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This sub has inspired me to do better.
| 0non-cybersec
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Reddit
|
Fixed points of operators with wavefront constraint. <p>Let <span class="math-container">$M$</span> be closed manifold and <span class="math-container">$\Psi^0(M)$</span> denote the space of pseudodifferential operators of order <span class="math-container">$0$</span>. For <span class="math-container">$Q\in \Psi^0(M)$</span> one can define the operator wave-front set <span class="math-container">$\mathrm{WF}'(Q)\subset T^*M\backslash 0$</span>, which consists of those points in phase-space, where <span class="math-container">$Q$</span> is microlocally non-trivial (see e.g. Definition 6.5 <a href="https://math.mit.edu/%7Ephintz/18.157-S19/18.157.pdf" rel="nofollow noreferrer">here</a>). Suppose now that <span class="math-container">$U\subset T^*M\backslash 0$</span> is an open conic set and let <span class="math-container">$\Psi^0_U(M)$</span> consist of those operators with <span class="math-container">$\mathrm{WF}'(Q)\subset U$</span>.</p>
<p><strong>Question.</strong> Given <span class="math-container">$f\in \mathscr{D}'(M)$</span> is there a way to tell whether <span class="math-container">$f$</span> is fixed by some <span class="math-container">$Q\in \Psi^0_U(M)?$</span> In other words, can we characterise the space <span class="math-container">$F_U= \bigcup_{Q\in \Psi^0_U(M)}\ker (\mathrm{id}-Q)$</span> in terms of <span class="math-container">$U$</span>?</p>
<p>Denoting <span class="math-container">$\pi:T^*M\rightarrow M$</span> the base-point projection, if <span class="math-container">$\pi^{-1}(\mathrm{supp}(f))\subset U$</span>, then one can simply take <span class="math-container">$Q$</span> to be multiplication by <span class="math-container">$q\in C^\infty(M)$</span> with <span class="math-container">$\mathrm{supp}(q)\subset \pi(U)$</span> and <span class="math-container">$q\equiv 1$</span> on <span class="math-container">$\mathrm{supp} f$</span>.</p>
<p>The more interesting case is when the complement of <span class="math-container">$U$</span> intersects every fibre of <span class="math-container">$T^*M$</span>, which gives a true microlocal constraint. E.g. if <span class="math-container">$Qf=f$</span> for <span class="math-container">$Q\in \Psi^0_U(M)$</span>, microlocality yields <span class="math-container">$\mathrm{WF}(f)\subset U$</span>.</p>
<p>What I'd be most keen to know is, how 'large' <span class="math-container">$F_U\cap C^\infty(M)$</span> is inside of <span class="math-container">$C^\infty(M)$</span>.</p>
| 0non-cybersec
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Stackexchange
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Netgear R7000 and R6400 routers are vulnerable to arbitrary command injection.
| 1cybersec
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Reddit
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subcaption bottom alignment of two pictures. <p>How to fix the alignment, so that both subfigures are bottom aligned?</p>
<pre><code>\documentclass[]{article}
\usepackage{subcaption}
\usepackage{tikz}
\usetikzlibrary{shapes.misc}
%opening
\begin{document}
\begin{figure}
\begin{subfigure}[b]{0.3\textwidth}
\begin{tikzpicture}
\node[shape=circle,draw=black, ] (B) at (0,1) {};
\node[shape=circle,draw=black,] (C) at (0,2) {};
\node[shape=circle,draw=black, ] (A) at (0,0) {};
\end{tikzpicture}
\end{subfigure}
%\hfill
\begin{subfigure}[b]{0.5\textwidth}
\[
\left(\begin{array}{cccccc}
& & & & &\\
& & & & & \\
& & & & & \\
& & & & & \\
& & & & & \\
& & & & &
\end{array}\right)
\]
\end{subfigure}
\caption{Edysdfsdfsdf}
\end{figure}
\end{document}
</code></pre>
| 0non-cybersec
|
Stackexchange
|
Display foreach loop iteration number in SSIS. <p>I need to keep a check on the iteration number for a foreach loop container task that I am running in Visual Studio 2017. How could I achieve this ?</p>
| 0non-cybersec
|
Stackexchange
|
How to use spot instance with amazon elastic beanstalk?. <p>I have one infra that use amazon elastic beanstalk to deploy my application.
I need to scale my app adding some spot instances that EB do not support.</p>
<p>So I create a second autoscaling from a launch configuration with spot instances.
The autoscaling use the same load balancer created by beanstalk.</p>
<p>To up instances with the last version of my app, I copy the user data from the original launch configuration (created with beanstalk) to the launch configuration with spot instances (created by me).</p>
<p>This work fine, but:</p>
<ol>
<li><p>how to update spot instances that have come up from the second autoscaling when the beanstalk update instances managed by him with a new version of the app?</p>
</li>
<li><p>is there another way so easy as, and elegant, to use spot instances and enjoy the benefits of beanstalk?</p>
</li>
</ol>
<p><strong>UPDATE</strong></p>
<p>Elastic Beanstalk add support to spot instance since 2019... see:
<a href="https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html</a></p>
| 0non-cybersec
|
Stackexchange
|
James Harden “Beard Drive”.
| 0non-cybersec
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Reddit
|
Is Pentti Linkola posing the most dangerous thoughts mankind has ever considered? Living an ascetic existence as a fisherman in a remote rural region of his frigid homeland, the Finnish philosopher has pondered mankind's position vis-a-vis the earth it inhabits and dares to utter the unspeakable..
| 0non-cybersec
|
Reddit
|
Rust wasm32-unknown-unknown Math functions not linking. <p>I'm trying the new wasm32-unknown-unknown target for Rust, and I'm experiencing issues invoking math functions (e.g. sin, cos, exp, atan2).</p>
<p>Cargo.toml:</p>
<pre><code>[package]
name = "wasm_math"
version = "0.1.0"
authors = ["..."]
[lib]
path = "src/lib.rs"
crate-type = ["cdylib"]
[dependencies]
</code></pre>
<p>src/lib.rs:</p>
<pre><code>#[no_mangle]
pub extern "C" fn invoke_sin(x: f64) -> f64 {
x.sin()
}
</code></pre>
<p>index.html:</p>
<pre><code><!doctype html>
<html lang="en">
<head><meta charset="utf-8"><title>Wasm Math</title></head>
<body></body>
<script>
const imports = { env: { } };
fetch("target/wasm32-unknown-unknown/release/wasm_math.wasm").then(response =>
response.arrayBuffer()
).then(bytes =>
WebAssembly.instantiate(bytes, imports)
).then(results => {
alert(results.instance.exports.invoke_sin(1.0));
});
</script>
</html>
</code></pre>
<p>I build the project with the command</p>
<pre><code>cargo build --release --target wasm32-unknown-unknown
</code></pre>
<p>When I open the html file in firefox, I get the following error:</p>
<pre><code>LinkError: import object field 'sin' is not a Function
</code></pre>
<p>Is there something wrong with my setup? Or is this a shortcoming in Rust/WebAssembly/Firefox? I could manually add the <code>sin</code> function to the <code>imports.env</code> object in the javascript, but that seems very hacky and I would have to do that for every math function that I use. Is there a better way?</p>
<p>I'm using the nightly Rust toolchain (nightly-x86_64-unknown-linux-gnu rustc 1.24.0-nightly (cddc4a62d 2017-12-26)) and Firefox 57.0.1 (64-bit).</p>
| 0non-cybersec
|
Stackexchange
|
I'm searching for book out of which this question have taken.Help me to find out.. <p><img src="https://i.stack.imgur.com/U3Y0P.jpg" alt="This is screenshot of question "></p>
<p>This question has been asked in UPSC exam and I have seen many books but I have not got this question anywhere. Please help me to find out.</p>
| 0non-cybersec
|
Stackexchange
|
Rowan Atkinson With His 1981 Aston Aston-Martin V8 Vantage.
| 0non-cybersec
|
Reddit
|
These Tiles.
| 0non-cybersec
|
Reddit
|
Where is the mistake in this logarithmic equation?. <p>The problem is:</p>
<blockquote>
<p>Given this equation find the possible values of $x$.
$$\log_{2}\left ( \frac{x+2}{x-1} \right )+\log_{2}\left [ (x+2)(x-1) \right ]=2$$</p>
</blockquote>
<p>First I defined the domain of the function.</p>
<ol>
<li><p>The denominator $x-1$ must not be zero: $x-1\neq0$.</p></li>
<li><p>The fraction $\frac{x+2}{x-1}$ must be bigger than zero: $\frac{x+2}{x-1}>0$.</p></li>
<li><p>The product $(x+2)(x-1)$ must be bigger than zero: $(x+2)(x-1)>0$.</p></li>
</ol>
<p>In the end I concluded that the domain should be $\left ]-\infty,-2\right [\cup \left ]1,+\infty\right[$.</p>
<p>Then I sarted to solve:</p>
<p>$$\begin{align*}
\log_{2}\left ( \frac{x+2}{x-1} \right )&+\log_{2}\left [ (x+2)(x-1) \right ]=2
\\
&\iff
\log_{2}(x+2)-\log_{2}(x-1)+\log_{2}(x+2)+\log_{2}(x-1)=2\\
&\iff
2 \cdot \log_{2}(x+2)=2\\
&\iff \log_{2}(x+2)=1 \\
&\iff x+2=2^1\\
&\iff x=2-2\\
&\iff x=0.
\end{align*}$$</p>
<p>This result is not in the domain!
Where I miss?</p>
| 0non-cybersec
|
Stackexchange
|
How can I determine if the operating system is POSIX in C?. <blockquote>
<p><strong>Related questions</strong><br>
<a href="https://stackoverflow.com/questions/430424/how-can-i-detect-the-operating-system-in-c-c">How can I detect the operating system in C/C++?</a></p>
</blockquote>
<p>How can I find out what operating system I am running under in GCC or in ANSI C?</p>
<p>I'd be fine If I can know if I'm running on POSIX.</p>
<hr>
<p>UPDATE:</p>
<p>It doesn't make a difference to me whether it is at compile time or run time. I'm using this in a debug routine, so performance isn't that important. </p>
<p>I'm looking for the path separator. Windows & Unix/Linux/BSD would be fine. </p>
<p>And, I'm trying to find the basename on a path. I found some solutions, but the solutions include a lot of includes which I do not want. I'm going to mod up <a href="http://www.koders.com/c/fidEB79B7607A210C3BB7B813E793465F9D469AE912.aspx" rel="noreferrer">this solution</a>.</p>
<hr>
<p>I'm on Mac OS X 10.4.11, and following <a href="http://bytes.com/topic/c/answers/215864-determine-os-compiler" rel="noreferrer">this URL</a>, I executed and got the following output:</p>
<pre><code>mac $ touch myfile.c
mac $ gcc -std=c99 -E -dM myfile.c
#define __DBL_MIN_EXP__ (-1021)
#define __FLT_MIN__ 1.17549435e-38F
#define __CHAR_BIT__ 8
#define __WCHAR_MAX__ 2147483647
#define __DBL_DENORM_MIN__ 4.9406564584124654e-324
#define __FLT_EVAL_METHOD__ 0
#define __DBL_MIN_10_EXP__ (-307)
#define __FINITE_MATH_ONLY__ 0
#define __GNUC_PATCHLEVEL__ 1
#define __SHRT_MAX__ 32767
#define __LDBL_MAX__ 1.79769313486231580793728971405301e+308L
#define __APPLE_CC__ 5367
#define __UINTMAX_TYPE__ long long unsigned int
#define __LDBL_MAX_EXP__ 1024
#define __SCHAR_MAX__ 127
#define __USER_LABEL_PREFIX__ _
#define __STDC_HOSTED__ 1
#define __LDBL_HAS_INFINITY__ 1
#define __DBL_DIG__ 15
#define __FLT_EPSILON__ 1.19209290e-7F
#define __LDBL_MIN__ 2.00416836000897277799610805135016e-292L
#define __ppc__ 1
#define __strong
#define __APPLE__ 1
#define __DECIMAL_DIG__ 33
#define __LDBL_HAS_QUIET_NAN__ 1
#define __DYNAMIC__ 1
#define __GNUC__ 4
#define __DBL_MAX__ 1.7976931348623157e+308
#define __DBL_HAS_INFINITY__ 1
#define __STRICT_ANSI__ 1
#define __weak
#define __DBL_MAX_EXP__ 1024
#define __LONG_LONG_MAX__ 9223372036854775807LL
#define __GXX_ABI_VERSION 1002
#define __FLT_MIN_EXP__ (-125)
#define __DBL_MIN__ 2.2250738585072014e-308
#define __DBL_HAS_QUIET_NAN__ 1
#define __REGISTER_PREFIX__
#define __NO_INLINE__ 1
#define _ARCH_PPC 1
#define __FLT_MANT_DIG__ 24
#define __VERSION__ "4.0.1 (Apple Computer, Inc. build 5367)"
#define __BIG_ENDIAN__ 1
#define __SIZE_TYPE__ long unsigned int
#define __FLT_RADIX__ 2
#define __LDBL_EPSILON__ 4.94065645841246544176568792868221e-324L
#define __NATURAL_ALIGNMENT__ 1
#define __FLT_HAS_QUIET_NAN__ 1
#define __FLT_MAX_10_EXP__ 38
#define __LONG_MAX__ 2147483647L
#define __FLT_HAS_INFINITY__ 1
#define __STDC_VERSION__ 199901L
#define _BIG_ENDIAN 1
#define __LDBL_MANT_DIG__ 106
#define __WCHAR_TYPE__ int
#define __FLT_DIG__ 6
#define __INT_MAX__ 2147483647
#define __LONG_DOUBLE_128__ 1
#define __FLT_MAX_EXP__ 128
#define __DBL_MANT_DIG__ 53
#define __WINT_TYPE__ int
#define __LDBL_MIN_EXP__ (-968)
#define __MACH__ 1
#define __LDBL_MAX_10_EXP__ 308
#define __DBL_EPSILON__ 2.2204460492503131e-16
#define __INTMAX_MAX__ 9223372036854775807LL
#define __FLT_DENORM_MIN__ 1.40129846e-45F
#define __PIC__ 1
#define __FLT_MAX__ 3.40282347e+38F
#define __FLT_MIN_10_EXP__ (-37)
#define __INTMAX_TYPE__ long long int
#define __GNUC_MINOR__ 0
#define __DBL_MAX_10_EXP__ 308
#define __LDBL_DENORM_MIN__ 4.94065645841246544176568792868221e-324L
#define __PTRDIFF_TYPE__ int
#define __LDBL_MIN_10_EXP__ (-291)
#define __LDBL_DIG__ 31
#define __POWERPC__ 1
mac $
</code></pre>
| 0non-cybersec
|
Stackexchange
|
Unable to boot the Laptop, Hard drive not responding. <p>When I start the Laptop, the Toshiba logo pops followed by message, "Reboot and select proper boot device or insert boot media in selected boot device and press a key".</p>
<p>I tried to modify the BIOS setup to boot from USB, but the change option is not active. Also, I'm unable to move within the BOIS setup since I'm not getting any display. </p>
<p>I need suggestion that, how to fix the problem? </p>
| 0non-cybersec
|
Stackexchange
|
\u\iamnotinterested2 offers an extensive and broad list of UK media publishing anti-EU fake news.
| 0non-cybersec
|
Reddit
|
JACK cannot start in realtime mode despite membership in audio group. <p>My jack server is unable to start in realtime mode despite me being in the <code>audio</code> group.</p>
<p>This is my setup:</p>
<pre class="lang-bsh prettyprint-override"><code>zegkljan@eddie:~$ lsb_release -r
Release: 16.10
zegkljan@eddie:~$ echo $USER
zegkljan
zegkljan@eddie:~$ grep audio /etc/group
audio:x:29:pulse,zegkljan
zegkljan@eddie:~$ groups $USER
zegkljan : zegkljan adm cdrom sudo audio dip plugdev lpadmin sambashare
zegkljan@eddie:~$ cat /etc/security/limits.d/audio.conf
# Provided by the jackd package.
#
# Changes to this file will be preserved.
#
# If you want to enable/disable realtime permissions, run
#
# dpkg-reconfigure -p high jackd
@audio - rtprio 95
@audio - memlock unlimited
#@audio - nice -19
zegkljan@eddie:~$ ulimit -a
core file size (blocks, -c) 0
data seg size (kbytes, -d) unlimited
scheduling priority (-e) 0
file size (blocks, -f) unlimited
pending signals (-i) 30955
max locked memory (kbytes, -l) unlimited
max memory size (kbytes, -m) unlimited
open files (-n) 1024
pipe size (512 bytes, -p) 8
POSIX message queues (bytes, -q) 819200
real-time priority (-r) 95
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 30955
virtual memory (kbytes, -v) unlimited
file locks (-x) unlimited
</code></pre>
<p>However, when I start jack via qjackctl with the "Realtime" option checked, I get the following messages (in the Messages window) containing the error "Cannot use real-time scheduling":</p>
<pre><code>Thu Dec 15 23:12:51 2016: Starting jack server...
Thu Dec 15 23:12:51 2016: JACK server starting in realtime mode with priority 10
Thu Dec 15 23:12:51 2016: self-connect-mode is "Don't restrict self connect requests"
Thu Dec 15 23:12:51 2016: ERROR: Cannot lock down 82274202 byte memory area (Cannot allocate memory)
Thu Dec 15 23:12:51 2016: Acquired audio card Audio1
Thu Dec 15 23:12:51 2016: creating alsa driver ... hw:K6|hw:K6|512|2|48000|0|0|nomon|swmeter|-|32bit
Thu Dec 15 23:12:51 2016: configuring for 48000Hz, period = 512 frames (10.7 ms), buffer = 2 periods
Thu Dec 15 23:12:51 2016: ALSA: final selected sample format for capture: 32bit integer little-endian
Thu Dec 15 23:12:51 2016: ALSA: use 2 periods for capture
Thu Dec 15 23:12:51 2016: ALSA: final selected sample format for playback: 32bit integer little-endian
Thu Dec 15 23:12:51 2016: ALSA: use 2 periods for playback
Thu Dec 15 23:12:51 2016: ERROR: Cannot use real-time scheduling (RR/10)(1: Operation not permitted)
Thu Dec 15 23:12:51 2016: ERROR: AcquireSelfRealTime error
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:capture_1'
Thu Dec 15 23:12:51 2016: New client 'system' with PID 0
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:capture_2'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:capture_3'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:capture_4'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:capture_5'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:capture_6'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:playback_1'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:playback_2'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:playback_3'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:playback_4'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:playback_5'
Thu Dec 15 23:12:51 2016: graph reorder: new port 'system:playback_6'
</code></pre>
<p>As far as I understand, being a member of the <code>audio</code> group should be enough to run in realtime. However, that is clearly not the case here. What am I doing wrong, or where could be the problem?</p>
<p>Feel free to ask for additional details.</p>
| 0non-cybersec
|
Stackexchange
|
How to use spot instance with amazon elastic beanstalk?. <p>I have one infra that use amazon elastic beanstalk to deploy my application.
I need to scale my app adding some spot instances that EB do not support.</p>
<p>So I create a second autoscaling from a launch configuration with spot instances.
The autoscaling use the same load balancer created by beanstalk.</p>
<p>To up instances with the last version of my app, I copy the user data from the original launch configuration (created with beanstalk) to the launch configuration with spot instances (created by me).</p>
<p>This work fine, but:</p>
<ol>
<li><p>how to update spot instances that have come up from the second autoscaling when the beanstalk update instances managed by him with a new version of the app?</p>
</li>
<li><p>is there another way so easy as, and elegant, to use spot instances and enjoy the benefits of beanstalk?</p>
</li>
</ol>
<p><strong>UPDATE</strong></p>
<p>Elastic Beanstalk add support to spot instance since 2019... see:
<a href="https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html</a></p>
| 0non-cybersec
|
Stackexchange
|
ITAP of the Great A'Tuin swimming through space..
| 0non-cybersec
|
Reddit
|
Basics in InfoSec - Guidelines/Suggestions. I'm looking to put in basic security measures in my new role. I'm thinking things like an InfoSec page on our website, an email address to send any questions or report any phishing etc., stuff along these kind of lines. Also, what technoligies would you suggest i.e. SIEM, IPS/IDS, web and mail filtering?
| 1cybersec
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Reddit
|
I assured her it wasn't personal. I lied..
| 0non-cybersec
|
Reddit
|
What is the most iconic spaceship not from Star Wars or Star Trek?. or better yet, what are *some of the most* iconic spaceship**s**
| 0non-cybersec
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Reddit
|
Prove G is a group given properties of G. <p>Let $G$ be a set with the operation $*$ such that:</p>
<ol>
<li><p>$G$ is closed with respect to $*$</p></li>
<li><p>$*$ is asociative</p></li>
<li><p>There exists an element $e \in G$ such that $e*x=x$ for all $x\in G$</p></li>
<li><p>Given $x \in G$, there exists $y\in G$ such that $y*x=e$</p></li>
</ol>
<p>The axioms of closure and asociativity are satisfied by the hypotesis 1 and 2.
Now it is left to prove that $x*e=x$ and $x*y=e$ to conclude $G$ is a group. I've made some sustitutions to try to get the commutative property on those produts but I don't get a way to achieve it. These set of suppositions are then stronger than the group definition as they can be deduced from these ones right?
What shoud I compute to prove $G$ is a group?</p>
| 0non-cybersec
|
Stackexchange
|
Isolating Internet-accessible internal hosts from each other. <p>I'm a sysadmin in a small company, and have what I would describe as a moderate understanding of networking. I'm trying to create a situation in which a number of internal hosts are accessible over RDP from the Internet, but cannot communicate with the office network, nor each other. All will share a single public IP, so users connecting from the Internet will append a port number in the Remote Desktop Connection client in order to reach a particular one of these hosts. The hosts will be virtual machines on ESXi.</p>
<p>Having done some initial Googling, I spent a day playing with Vyatta, and am really impressed with it (in particular I find its documentation excellent). However, I realise that my problem is not understanding specific concepts or following instructions; it's that I don't properly know what network technologies and topology I should be using. I imagine there are multiple possibilities. I've heard VLANs mentioned a lot.</p>
<p>I should add that we have a mid-range small business firewall and that, if necessary, we can designate one of its ports to be its own interface that passes traffic exclusively between the WAN and a spare physical NIC on the ESXi host.</p>
<p>So my question is, what technologies and topology would you consider most suited to creating the situation I have described? To recap, I want multiple internal VMs that are isolated both from each other and from the rest of our office network, but can be connected to from the Internet via RDP (on a single public IP but unique port numbers).</p>
<p>Many thanks in advance.</p>
| 0non-cybersec
|
Stackexchange
|
A pigeon shit straight into my beer.
| 0non-cybersec
|
Reddit
|
"Hello, cutie pie".
| 0non-cybersec
|
Reddit
|
20.04 takes a long time to boot from a m.2 ssd. <p>Noob here, I managed to install 20.04 to an SSD, a Samsung 850 EVO 250Gb (mz-n5e250) however, I am getting a fairly long boot time compared to a standard ssd install.
First of all, noticed that during install it detected the m.2 as /dev/sdd instead of /dev/nvme...probably nothing, installation proceeded without issue.
Now this is dual boot setup alongside Windows 10. Grub works fine and then it's a long wait...When I get to Ubuntu desktop I notice that in favourites I can see that root, efi and home are mounted as media, I haven't seen this before. Anyway, digging deeper the culprit appears to be udisks2:</p>
<p>sudo systemd-analyze blame:</p>
<pre>32.803s udisks2.service
6.452s NetworkManager-wait-online.service
5.296s plymouth-quit-wait.service
563ms systemd-logind.service
559ms snap-gnome\x2d3\x2d34\x2d1804-33.mount
558ms snap-gtk\x2dcommon\x2dthemes-1506.mount
557ms snap-gnome\x2d3\x2d34\x2d1804-27.mount</pre>
<p>and critical-chain:</p>
<pre>
graphical.target @34.045s
└─<b>udisks2.service @1.241s +32.803s</b>
└─basic.target @1.189s
└─sockets.target @1.189s
└─<b>snapd.socket @1.188s +478us</b>
└─sysinit.target @1.185s
└─<b>systemd-timesyncd.service @894ms +290ms</b>
└─<b>systemd-tmpfiles-setup.service @867ms +25ms</b>
└─local-fs.target @863ms
└─run-user-1000-gvfs.mount @22.329s
└─run-user-1000.mount @22.182s
└─swap.target @815ms
└─<b>dev-disk-by\x2duuid-3f951984\x2d35cf\x2d4e0d\x2d8dee\x2d072d2f4c8d66.swap @767ms +47ms</b>
└─dev-disk-by\x2duuid-3f951984\x2d35cf\x2d4e0d\x2d8dee\x2d072d2f4c8d66.device @759ms
</pre>
<p>So, I checked fstab thinking something might be amiss:</p>
<pre>
# <file system> <mount point> <type> <options> <dump> <pass>
# / was on /dev/sdd1 during installation
UUID=2ac96265-f633-42a7-8ab4-5f3f4a9065ec / ext4 errors=remount-ro 0 1
# /boot/efi was on /dev/sda2 during installation
UUID=6AE9-5D89 /boot/efi vfat umask=0077 0 1
# /home was on /dev/sdd3 during installation
UUID=8e1a5a66-e062-42cd-bf93-2042e61dd9ba /home ext4 defaults 0 2
# swap was on /dev/sdd2 during installation
UUID=3f951984-35cf-4e0d-8dee-072d2f4c8d66 none swap sw 0 0
</pre>
<p>compared it to blkid:</p>
<pre>/dev/sdd2: UUID="3f951984-35cf-4e0d-8dee-072d2f4c8d66" TYPE="swap" PARTUUID="90c89aee-5a06-4d7b-b292-45ea9a1bf90b"
/dev/sdd1: UUID="2ac96265-f633-42a7-8ab4-5f3f4a9065ec" TYPE="ext4" PARTUUID="6a78d7fe-ebdf-44c4-9839-58bd1d3435a2"
/dev/loop0: TYPE="squashfs"
/dev/loop1: TYPE="squashfs"
/dev/loop2: TYPE="squashfs"
/dev/loop3: TYPE="squashfs"
/dev/loop4: TYPE="squashfs"
/dev/loop5: TYPE="squashfs"
/dev/loop6: TYPE="squashfs"
/dev/loop7: TYPE="squashfs"
/dev/sda1: LABEL="Recovery" UUID="0294E89394E88A8D" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="166342dd-a166-4598-b639-ac44b12e1ffe"
/dev/sda2: UUID="6AE9-5D89" TYPE="vfat" PARTLABEL="EFI system partition" PARTUUID="9218c53d-42bd-4ca3-b222-e6fa7d52378f"
/dev/sda4: UUID="84C2F292C2F28826" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="5889556a-909f-4410-a177-30cb5b843280"
/dev/sdc2: LABEL="Data" UUID="ACF4143FF4140DE8" TYPE="ntfs" PARTLABEL="Basic data partition" PARTUUID="981bc30b-aedb-4269-814b-b768667d4dde"
/dev/sdd3: UUID="8e1a5a66-e062-42cd-bf93-2042e61dd9ba" TYPE="ext4" PARTUUID="ff33cea9-5f9a-476a-b2b4-a3d2da50e67e"
/dev/loop8: TYPE="squashfs"
/dev/sda3: PARTLABEL="Microsoft reserved partition" PARTUUID="b488c487-f54f-4f7f-a144-18e91e01efbc"
/dev/sdc1: PARTLABEL="Microsoft reserved partition" PARTUUID="1b884629-3787-4cab-a008-1f3de408c226"
</pre>
<p>So, everything looks okay (as far as I can tell). </p>
<p>I ran 'sudo cat /var/log/syslog | grep -i udisks2':</p>
<pre>May 7 10:56:51 ollie-MS-7B87 dbus-daemon[1103]: [session uid=125 pid=1103] Activating via systemd: service name='org.gtk.vfs.<b>UDisks2</b>VolumeMonitor' unit='gvfs-<b>udisks2</b>-volume-monitor.service' requested by ':1.2' (uid=125 pid=1097 comm="/usr/libexec/tracker-miner-fs " label="unconfined")
May 7 10:56:51 ollie-MS-7B87 dbus-daemon[900]: [system] Activating via systemd: service name='org.freedesktop.<b>UDisks2</b>' unit='<b>udisks2</b>.service' requested by ':1.27' (uid=125 pid=1119 comm="/usr/libexec/gvfs-<b>udisks2</b>-volume-monitor " label="unconfined")
May 7 10:57:11 ollie-MS-7B87 dbus-daemon[1472]: [session uid=1000 pid=1472] Activating via systemd: service name='org.gtk.vfs.<b>UDisks2</b>VolumeMonitor' unit='gvfs-<b>udisks2</b>-volume-monitor.service' requested by ':1.1' (uid=1000 pid=1467 comm="/usr/libexec/tracker-miner-fs " label="unconfined")
May 7 10:57:16 ollie-MS-7B87 gvfs-<b>udisks2</b>-vo[1517]: monitor says it's not supported
May 7 10:57:16 ollie-MS-7B87 gvfs-<b>udisks2</b>-vo[1119]: monitor says it's not supported
May 7 10:57:16 ollie-MS-7B87 dbus-daemon[1472]: [session uid=1000 pid=1472] Successfully activated service 'org.gtk.vfs.<b>UDisks2</b>VolumeMonitor'
May 7 10:57:16 ollie-MS-7B87 dbus-daemon[1103]: [session uid=125 pid=1103] Successfully activated service 'org.gtk.vfs.<b>UDisks2</b>VolumeMonitor'
May 7 10:57:16 ollie-MS-7B87 gvfs-<b>udisks2</b>-vo[1517]: monitor says it's not supported
May 7 10:57:16 ollie-MS-7B87 gvfs-<b>udisks2</b>-vo[1517]: monitor says it's not supported
May 7 10:57:16 ollie-MS-7B87 gvfs-<b>udisks2</b>-vo[1119]: monitor says it's not supported
May 7 10:57:16 ollie-MS-7B87 tracker-miner-f[1467]: remote volume monitor with dbus name org.gtk.vfs.<b>UDisks2</b>VolumeMonitor is not supported
May 7 10:57:16 ollie-MS-7B87 gvfs-<b>udisks2</b>-vo[1119]: monitor says it's not supported
May 7 10:57:16 ollie-MS-7B87 tracker-extract[1096]: remote volume monitor with dbus name org.gtk.vfs.<b>UDisks2</b>VolumeMonitor is not supported
May 7 10:57:16 ollie-MS-7B87 tracker-extract[1466]: remote volume monitor with dbus name org.gtk.vfs.<b>UDisks2</b>VolumeMonitor is not supported
May 7 10:57:16 ollie-MS-7B87 tracker-miner-f[1097]: remote volume monitor with dbus name org.gtk.vfs.<b>UDisks2</b>VolumeMonitor is not supported
May 7 10:57:23 ollie-MS-7B87 udisksd[942]: Acquired the name org.freedesktop.<b>UDisks2</b> on the system message bus
</pre>
<p>I can confirm that issue is not confined to the m.2 but also an external ssd on a fresh install. udisks2 is freaking out again mounting /efi , /root and /home as media in the favourites bar. Guessing there is something in my system setup that Ubuntu doesn't particularly like.</p>
| 0non-cybersec
|
Stackexchange
|
Chef node not checking in with the server. <p>I've recently moved my clients from one chef server to another, and now none of my nodes are checking in properly. I can manually run 'chef-client' successfully, and I do have the <code>chef-client::default</code> cookbook defined, yet they will not "check in".</p>
<p>These are Ubuntu 14.04 nodes connecting to a Chef 12 server on Ubuntu 14.04. The only difference between this server and the old one was that I've also moved to using named environments with specific cookbook versions for our own cookbooks. I haven't explicitly provided entries for the chef-client cookbook or any others since I'm fine with running the latest versions.</p>
<p>I can manually run <code>chef-client</code> without error, but I do not see any logs under <code>/var/log/chef</code> so I'm not sure where else to look. I even went so far as to set the <code>chef_client::interval</code> attribute on the environment to <code>1800</code>, but still no luck. Any help would be greatly appreciated.</p>
| 0non-cybersec
|
Stackexchange
|
Plane trying to land in a storm.
| 0non-cybersec
|
Reddit
|
How to merge multiple lines into single line but only for block of lines separated by blank line. <p>I am trying to merge multiple lines into single one but with additional conditions.</p>
<p>My input file looks like:</p>
<pre><code>Dm1*( stuff1 + stuff2 -
stuff3 + stuff4)
+ D1*(D1stuff1 + D1sstuff2 + D1stuff3 + D1stuff4 +
D1stuff5 -
D1stuff6 )
+ D2*(D2stuff)
</code></pre>
<p>So there are multiples lines which are also separated by blank lines. All the <code>*stuff*</code> contains long and complicated expressions which also can contain parenthesis.</p>
<h3>I want to keep the blank lines as it is but merge the other multiple lines.</h3>
<p>The expected output is</p>
<pre><code>Dm1*( stuff1 + stuff2 - stuff3 + stuff4)
+ D1*(D1stuff1 + D1sstuff2 + D1stuff3 + D1stuff4 + D1stuff5 - D1stuff6 )
+ D2*(D2stuff)
</code></pre>
<p>All the current attempts like</p>
<pre><code>awk '{printf("%s",$0)}'
</code></pre>
<p>put everything in a single line. Should I loop over lines or is there any way to identify the blocks between blank lines and apply something into that?</p>
| 0non-cybersec
|
Stackexchange
|
Marginalia inside tcolorbox. <p>I created some fancy <code>tcolorbox</code> for writing solutions of the problems:</p>
<pre><code>\documentclass{scrartcl}
\usepackage[breakable, many]{tcolorbox}
\usepackage{changepage}
\usepackage{lipsum}
\NewTColorBox[auto counter,number within=section]{solution}{+O{}}{%
breakable, enhanced,sharpish corners, colframe=blue!50,colback=white,coltitle=blue!60!black,
fonttitle=\itshape\bfseries, parbox = false,
check odd page,toggle left and right,
boxrule=0.3mm,top=0mm,bottom=0mm,left=2.1cm,right=1mm,
%grow to right by=1cm,
%toprule=1mm,
overlay={%
\ifoddpage%
\draw[red!75!black,line width=1pt]
([xshift=2.02cm]frame.north west)--([xshift=2.02cm]frame.south west);%
\else%
\draw[red!75!black,line width=1pt]
([xshift=-1.95cm]frame.north east)--([xshift=-1.95cm]frame.south east);%
\fi%
},
underlay={\begin{tcbclipinterior}
\draw[help lines,step=5mm,blue!20!white,shift={(interior.north west)}]
(interior.south west) grid (interior.north east);
\end{tcbclipinterior}},
title={solution},
label={},
attach title to upper=\quad,
after upper={\par\hfill%
{}},
lowerbox=ignored,
}
\begin{document}
\begin{solution}
\lipsum[1-40]
\end{solution}
\end{document}
</code></pre>
<p><img src="https://i.stack.imgur.com/oRXu8.jpg" alt="enter image description here"></p>
<p>I need the same <code>tcolorbox</code> with the possibility of margin notes behind the red line. It would be nice if the field behind the red line will coincide with the actual size of the current page margins</p>
| 0non-cybersec
|
Stackexchange
|
Cloud Forensics: Box. It seems we really enjoy forensicating desktop apps for cloud services. Last week we started from really secure cloud service app – Mega. This time we are going to continue with another, much more forensically friendly app, – Box.
So Box is a popular enterprise content management platform, but, of course, can be used by regular users for managing content in the cloud. Why do we say it’s much more forensically friendly? You will know the answer by the end of this post.
More: http://cyberforensicator.com/2018/04/21/cloud-forensics-box/
| 1cybersec
|
Reddit
|
Southwest jet getting a custom paint job.
| 0non-cybersec
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Reddit
|
After posting a few pre-wedding makeup trials, here's a picture from the wedding day [MISC].
| 0non-cybersec
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Reddit
|
I'm a Christian woman that had an abortion yesterday. Surprisingly, I had a positive experience!. Hi /r/TwoX, I just wanted to share my abortion experience with you and provide support for others who may have been in my situation. <3 I read a lot about other experiences on this sub when I was first making a decision, so I thought it'd be nice to share too.
Disclosure: The title of my post may be a little misleading. Although I do identify myself as a Christian (grew up radically conservative, now identify as a non-denominational), my views are certainly more "liberal" than average. For example, I believe that evolution and religion can coexist, that God is too loving and compassionate a god to condemn homosexuals, etc.
That said, abortion was something that I wasn't so open to myself -- I'm all for pro-choice legislation, but personally, I was pro-life. Then I got pregnant. My boyfriend and I are in a stable, long-term relationship, adults in our early twenties, with stable jobs and decent money. But it was still something we weren't ready for.
I was vehemently opposed to an abortion and my boyfriend and I fought about it constantly. I did some soul-searching on my own and realized that although I was opposed to abortion, I didn't really want a child at this point. My upbringing told me it was the "noble" thing to keep the pregnancy, but logic also told me that it was a terrible idea to bring a kid into the world that a) wasn't loved from the get-go b) might have a father that resents him and c) had a mother that didn't take the proper precautions to care for him (terrible eating habits, stress from work, some alcohol and smoking).
Anyway, I mulled over it for a couple weeks, primarily because this decision was one that completely went against what my moral code said. I was afraid of feeling regretful, sad, depressed, guilty, and even unworthy of God.
I did a lot of research and found that there wasn't much about Christian women and abortions (minus the fear-mongering). I read comments online where people had cited no direct opposition to abortion in the Bible, and even some accounts that God had ordered a man to make an abortion-type drink in the Old Testament. That was eye-opening. Then I found some stories of women who were comforted by the idea of grace and forgiveness. All of these things combined helped me come to terms that terminating the pregnancy was the right choice to make for me, despite a struggle (maybe?) of beliefs.
I told my boyfriend who was very supportive. I was already frightened by the things I read about abortion procedures and didn't want to put myself in a distressing mental space. I opted to do a medical D&C procedure (I was about 8 weeks along) under general anesthesia. If you can afford to go this route, PLEASE DO!!
The procedure couldn't have gone any better. I was put to sleep holding the nurse's hand and then next thing I knew, I was in the recovery room with my boyfriend. Thus far, I've had a bit of cramping and bleeding, but physically *and* mentally, I feel pretty good. I mostly feel relief and gratefulness, with a tinge of weirdness that I can't really explain.
I know that in time, my feelings may change, and I don't really know how to be prepared for that. An abortion is a difficult decision to make, whichever choice you take. But for now I don't feel like my life has changed dramatically!
My question for those of you who have been here: had your feelings changed after the abortion? Did you feel like your life has changed dramatically because of it?
Are there any ladies out there that are in a similar place as me (belief wise) that have gone through this experience?
| 0non-cybersec
|
Reddit
|
Tomorrow you'll forget everything you ever read. You can give 2 books for your future self to be as wise as possible. What do you pick?. Consider that tomorrow all your knowledge that goes beyond 'basic' every-day life situations is erased. You still have basic social skills, can take care of yourself and significant others, and can do a normal job to support yourself and your family. In a practical sense, you're still a functional human being, but everything you ever learned about any topic is gone.
You need to pick 2 books to give to your future knowledgeless self to regain what you think is the most important thing to know to become better. What books would you choose to best achieve that goal, and why?
| 0non-cybersec
|
Reddit
|
Hawthorne Burger from Umami. Description in comments [1830x1829] [OC].
| 0non-cybersec
|
Reddit
|
How to use spot instance with amazon elastic beanstalk?. <p>I have one infra that use amazon elastic beanstalk to deploy my application.
I need to scale my app adding some spot instances that EB do not support.</p>
<p>So I create a second autoscaling from a launch configuration with spot instances.
The autoscaling use the same load balancer created by beanstalk.</p>
<p>To up instances with the last version of my app, I copy the user data from the original launch configuration (created with beanstalk) to the launch configuration with spot instances (created by me).</p>
<p>This work fine, but:</p>
<ol>
<li><p>how to update spot instances that have come up from the second autoscaling when the beanstalk update instances managed by him with a new version of the app?</p>
</li>
<li><p>is there another way so easy as, and elegant, to use spot instances and enjoy the benefits of beanstalk?</p>
</li>
</ol>
<p><strong>UPDATE</strong></p>
<p>Elastic Beanstalk add support to spot instance since 2019... see:
<a href="https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html</a></p>
| 0non-cybersec
|
Stackexchange
|
ITAP Paragliding at the sea..
| 0non-cybersec
|
Reddit
|
how can I use the react-native-datetime-modal-picker with input?. <p>Everyone.
I want to link the input box and date-picker.
so I have tried this.</p>
<pre><code>import React from 'react';
import { Item, Input, Label } from 'native-base';
import DateTimePicker from 'react-native-modal-datetime-picker';
import moment from 'moment';
...
render() {
const { label, value, mode, displayFormat, ...other } = this.props;
const { show } = this.state;
return (
<React.Fragment>
<Item {...other} floatingLabel onPress={this.showDateTimePicker}>
<Label>{label}</Label>
<Input editable={false} value={value ? moment(value).format(displayFormat) : ''} onPress={this.showDateTimePicker} />
</Item>
<DateTimePicker
date={value ? new Date(value) : new Date()}
isVisible={show}
mode={mode}
onConfirm={this.handleDatePicked}
onCancel={this.hideDateTimePicker}
/>
</React.Fragment>
);
}
...
</code></pre>
<p>but unfortunately, onPress event doesn't handle when the TextInput disabled in IOS.
so, please help me to solve this problem.</p>
<p>Here is the project environment.</p>
<pre><code>...
"expo": "^34.0.1",
...
"moment": "^2.24.0",
"native-base": "^2.13.7",
"react": "16.8.3",
"react-native": "https://github.com/expo/react-native/archive/sdk-34.0.0.tar.gz",
"react-native-modal-datetime-picker": "^7.5.0",
...
</code></pre>
<p><a href="https://snack.expo.io/@whitedragon226/formdatetimepicker" rel="nofollow noreferrer">Watch on Expo Snake (before)</a><br>
<a href="https://snack.expo.io/@whitedragon226/formdatetimepicker1" rel="nofollow noreferrer">Watch on Expo Snake (fixed)</a></p>
| 0non-cybersec
|
Stackexchange
|
My dog's embarrassing baby photo..
| 0non-cybersec
|
Reddit
|
A way to do this integral without spherical coordinates?. <p>Let $B$ be the unit ball in $\mathbb R^3$. How can one integrate</p>
<p>$$\int_B e^{(x^2+y^2+z^2)^{5/2}}dx\ dy \ dz\ ?$$</p>
<p>The natural idea is spherical coordinates, but it seems like there is a nicer way to tackle this. Am I missing something obvious?</p>
| 0non-cybersec
|
Stackexchange
|
Caprese salad from MAST' in downtown Boston [OC] [5312x2899].
| 0non-cybersec
|
Reddit
|
How to use spot instance with amazon elastic beanstalk?. <p>I have one infra that use amazon elastic beanstalk to deploy my application.
I need to scale my app adding some spot instances that EB do not support.</p>
<p>So I create a second autoscaling from a launch configuration with spot instances.
The autoscaling use the same load balancer created by beanstalk.</p>
<p>To up instances with the last version of my app, I copy the user data from the original launch configuration (created with beanstalk) to the launch configuration with spot instances (created by me).</p>
<p>This work fine, but:</p>
<ol>
<li><p>how to update spot instances that have come up from the second autoscaling when the beanstalk update instances managed by him with a new version of the app?</p>
</li>
<li><p>is there another way so easy as, and elegant, to use spot instances and enjoy the benefits of beanstalk?</p>
</li>
</ol>
<p><strong>UPDATE</strong></p>
<p>Elastic Beanstalk add support to spot instance since 2019... see:
<a href="https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html</a></p>
| 0non-cybersec
|
Stackexchange
|
Jean-Paul Sartre's ethical critique: why are we obsessed with thinking in ethical models? (reading included). The reading begins on page 9 of [this text](http://philosophy.lander.edu/intro/articles/sartre-a.pdf) with the story of the student poised to face a tough decision.
This subreddit seems to focus a lot on ethics and ethical models, and how to act inside them. There are two threads right now on "justification" and it seems like threads in that vein seem to come up every day or two. That's not to say that they aren't good questions--they are--but always seem to run up against the limitations of ethical models that they are trying to operate from. I was thinking about this mode of thinking a little bit over the last few days and had revisited Aristotle's Nichomachean Ethics a little while ago when I was reminded about a little story from Sartre that I read some time ago. Within that little story up in the reading, the critique that he had really resonated within me. Particularly this bit: "No rule of general morality can show you what you ought to do: no signs are vouchsafed in this world." Which isn't to say that all ethics are completely arbitrary, but that, as the reading continues to say, that me and my actions are the arbiter. I believe that at its core, this is Aristotelian (especially related to Gadamer's relation to the element of application in *Truth and Method*), but that's besides the point. The point rather is that I feel like Sartre is really getting at the heart of the matter: ethical models for tough decisions will consistently fail us.
The two examples--the student choosing between his dying mother and joining the resistance and the failed Jesuit--illustrate a wonderful point: that tough decisions are rife with context. Thought experiments about pulling train levers only go so far. The formulae of Kantian or Utilitarian ethics will never encapsulate the dynamism of the human experience. JS Mill and Kant do have excellent treatises on their respective models, but it's the opinion of this author that they are unsatisfactory. I don't want to escape into a rabbit hole of obscurantism but Sartre and Aristotle seem to pierce the issue entirely: it is in the event of the decision and action that "ethicality" lies.
| 0non-cybersec
|
Reddit
|
Boot back to Windows?. <p>I'm sure this question has been asked thousands of times but here I go: so I installed the latest Ubuntu (dual booting with my Windows 8) and it keeps booting to the USB I used. If I take it out it try's to search for it and fails obviously so it says it can't find a boot disk. I need to get back to my windows how do I do this?!</p>
| 0non-cybersec
|
Stackexchange
|
IIS7 as site title. <p>When I search for my website on google both the title and description are showing as IIS7, how can I change this to a proper description?</p>
| 0non-cybersec
|
Stackexchange
|
arXiv:math/0111242v1 [math.PR] 22 Nov 2001
ar
X
iv
:m
at
h/
01
11
24
2v
1
[
m
at
h.
P
R
]
2
2
N
ov
2
00
1
The gambler’s ruin problem in path
representation form
Oscar Bolina
Instituto de F́ısica
Universidade de São Paulo
Caixa Postal 66318
São Paulo 05315-970 Brasil
E-mail: [email protected]
Abstract
We analyze the one-dimensional random walk of a particle on the
right-half real line. The particles starts at x = k, for k > 0, and ends
up at the origin. We solve for the probabilities of absorption at the
origin by means of a geometric representation of this random walk in
terms of paths on a two-dimensional lattice.
Key words: Random Walk.
MSC numbers: 82B41
1 Introduction
We consider the classical one-dimensional random walk of a particle on the
right-half real line. We assume that the particle is initially at position x = k,
k > 0, and moves to the right with probability p or to the left with probability
1−p. We consider that the particle is absorbed at the origin without fixing the
number of steps needed to get there. We calculate the probability P (x = k)
that the particles end up at the origin, given that it starts at x = k, by
means of a geometric representation of this random walk in terms of paths
on a two-dimensional lattice.
It is well-known that the probability P (x = k) is the kth power of P (x = 1):
P (x = k) = (P (x = 1))
k
. (1.1)
Because of this, we are not really going to prove the results that lead to (1.1)
(the proofs are quite obvious in our context). Instead, we prefer to use our
geometric representation as a ”visual” proof of these results.
1
http://arxiv.org/abs/math/0111242v1
bolina 2
2 The probabilities of absorption
A representation of this random walk in terms of path on a two-dimensional
lattice is given in Fig. 1 for an arbitrary initial position x = k (k > 0) of
the particle. In this representation, each horizontal lattice bond represents
a step of the particle to the right, while each vertical bond represents a step
to the left.
Let n denote the total number of steps of the particle to the right until it is
absorbed at the origin. (The number of steps to the left will then be n+ k.)
A path of length n — or simply a path — of the particle on this lattice
is the set of horizontal and vertical bonds from the origin to the point of
coordinates (n, n+ k) on the line L, as shown.
Let Ck(n) be the total number of paths of length n from the origin to point
(n, n+ k). A simple combinatorics analysis leads to the following expression
for Ck(n):
Ck(n) = k
(n+m− 1)!
n! m!
= k
(2n+ k − 1)!
n!(n + k)!
=
k
(2n+ k)
(
2n + k
n
)
. (2.2)
The probability that the particle arrives at the origin given the initial con-
dition that it starts at position x = k is given by
P (x = k) =
∞
∑
n=0
Ck(n)p
n(1− p)n+k. (2.3)
We show next how to carry out the summation in (2.3) using the geometry
of the lattice paths. We will need to solve explicitly for the first three values
of k, k = 1, 2, 3, before arriving at the general solution (1.1) by induction.
3 The case k = 1
The expression (2.2) for Ck=1(n) = C(n) in the particular case the particle
starts at k = 1 is the nth Catalan number
C(n) =
(2n)!
n! (n+ 1)!
=
1
n + 1
(
2n
n
)
. (3.4)
The Catalan numbers have some geometric properties associated with paths
on the lattice that we now explore. The first result is the following
bolina 3
k
n
L
(n, n+k)
Figure 1: Paths on the lattice, from the origin to the point (n, n+ k) on the
line L, represent the number of steps to the right (n), and to the left (n+k)
that the particle has taken in its random walk from position x = k on the real
axis until it is absorbed at the origin.
Theorem 3.1 The number C(n) given by (3.4) satisfies the following equa-
tion
C(n) =
n
∑
α=1
C(α− 1) C(n− α). (3.5)
Proof. Fig. 2 illustrates the theorem for n = 4. For this proof, we
have translated the paths in C(4) one unit to the left so as to make
the paths touch the line L. These paths can be decomposed as follows.
Starting from n = 0, and repeating the procedure for n = 1, n = 2 and
n = 3, raise vertical lines from the n-axis to the line L. The vertical
line at n = α generates two sets of paths, the set C(α) to the left of
n = α, and the set C(4 − α) to the right of n = α. These two sets of
paths contribute a factor C(α)C(4−α) to the number C(4). The sum
of these factors for values from zero to 3 is C(4). �
bolina 4
= + + +
C(0) C(3)C(4) C(3) C(0)C(2) C(1)C(1) C(2)
Figure 2: Decomposition of C(n).
3.1 Finding P (x = 1)
Now if we set
F (z) =
∞
∑
α=1
C(α− 1) zα, (3.6)
then we obtain
F 2(z) =
∞
∑
α,β=1
C(α− 1)C(β − 1) zα+β
=
∞
∑
n=2
n−1
∑
α=1
C(α− 1)C(n− α− 1) zn
=
∞
∑
n=2
C(n− 1) zn = F (z)− z,
so that (3.6) obeys the equation
F 2(z) = F (z)− z. (3.7)
Solving (3.7) for F we get the solutions
F (z) =
1±
√
1− 4z
2
. (3.8)
Observe now that the summation (3.6) when z = p(1− p) is (up to a factor)
the probability function (2.3) when k = 1. Thus we have
P (x = 1) =
F (p− p2)
p
=
1±
√
1− 4p+ 4p2
2p
=
1± (1− 2p)
2p
. (3.9)
bolina 5
This last expression gives the classical results for the probability that the
particle will end up at the origin given that it starts at k = 1. The solutions
depend on whether p ≤ 1/2 or p ≥ 1/2. For p ≤ 1/2, we get P (x = 1) = 1,
and for p ≥ 1/2 we get
P (x = 1) =
1− p
p
. (3.10)
For an interpretation of these results for other values of p, see reference [1].
4 The case k = 2
When k = 2, then (2.3) becomes
P (x = 2) =
∞
∑
n=0
C2(n)p
n(1− p)n+2. (4.11)
The coefficient C2(n) can be written in terms of C(n) on account of the
following result
Theorem 4.1 The following relationship holds for the coefficients C2(n) and
C(n) given by (2.2)
C2(n) = C(n + 1). (4.12)
Proof. In Fig. 3 we have drawn the paths that in C2(n) (in red), and
the paths in C(n+1). Now, translate the paths in blue one unit to the
left. The blue paths go over the red ones. It is a perfect match and we
are done. �
If we now substitute (4.12) into (4.11) we obtain, after some simple calcula-
tions,
P (x = 2) =
∞
∑
n=0
C(n+1)pn(1−p)n+2 =
∞
∑
l=1
C(l)pl−1(1−p)l+1 =
P (x = 1)
p
−
1 − p
p
and substituting for P (x = 1) from (3.10) we get
P (x = 2) =
(1− p)2
p2
bolina 6
2
1
n+1n
Figure 3: Relationship between C2(n) and the Catalan numbers.
if p ≥ 1/2, and P (x = 2) = 1 for p ≤ 1/2.
5 The case k = 3
We need this case to establish (1.1) for all values of k.
Theorem 5.1 For k ≥ 3 the following recurrence relation holds between the
coefficient Ck(n) and the coefficients Ck−1(n+ 1) e Ck−2(n+ 1)
Ck(n) = Ck−1(n+ 1)− Ck−2(n+ 1). (5.13)
Proof. The geometric representation of (5.13) is depicted in Fig. 4.
To prove it, note that if we remove the paths that stem from the two
purple bonds on the right side of Fig. 4 and translate the remaining
set of paths one unit to the left, we get exactly Ck(n). But the number
of paths we eliminated is exactly Ck−2(n+ 1), as the figure illustrates.
This completes the proof. �
The probability of absorption for k = 3
P (x = 3) =
∞
∑
n=0
C3(n)p
n(1− p)n+3. (5.14)
bolina 7
k
k−2
−=
k−1
n n+1 n+1
Figure 4: The recurrence relation (5.13).
Substituting for C3(n) its value from (5.13),
C3(n) = C2(n+ 1)− C1(n+ 1),
we obtain, after some straightforward computation,
P (x = 3) =
(1− p)3
p3
for p ≥ 1/2 and P (x = 3) = 1 for p ≤ 1/2.
6 The general case
By induction on k we can now prove, as the three cases above suggest, the
following result.
Theorem 6.1 The probability P (x = k) of absorption of the particle at the
origin, given that it starts at x = k, is given by
P (x = k) = (P (x = 1))
k
.
bolina 8
Proof. The probability of absorption of a particle that starts at x =
k + 1 is equal to the probability that it moves one step to the left to
x = k times the probability that it is absorbed at the origin from there,
that is (1−p)P (x = k), plus the probability that the particle moves one
step to the right to x = k + 2 times the probability that it is absorbed
from there, that is pP (x = k + 2). Hence,
P (x = k + 1) = (1− p)P (x = k) + pP (x = k + 2),
from which we get
P (x = k + 2) =
1
p
P (x = k + 1)−
(1− p)
p
P (x = k), (6.15)
The induction step now follows easily from (6.15). �
Acknowledgments I was supported by FAPESP – Fundação de Am-
paro à Pesquisa do Estado de São Paulo – under grant 01/08485-6. I also
thank Pierluigi Contucci for other path representations.
References
[1] F. Mosteller, Fifty Challenging Problems in Probability, Dover, NY (1987)
p. 9
| 0non-cybersec
|
arXiv
|
Bruises forming in stretch marks from belt?. So, I have some light stretch marks on my sides and the front of my slowly becoming visible abs. When I do squats or deadlifts I now use a belt to give me a little more stability and it's really helping.
But every time I do these lifts I have bruising forming in those stretch marks. The belt isn't too tight, it's set to "just slightly uncomfortable to wear all the time" position and it's the Valsalva maneuver which pushes it into the support range.
Anyone know how to stop this? reduce it? anything to worry about?
| 0non-cybersec
|
Reddit
|
How to block completely Windows Update on my network. <p>I know it is not safe but I need to know how to prevent all computers in my LAN to download updates.</p>
<p>I have squid as proxy with dansguardian and I use OpenDNS...</p>
<p>I have put on a blacklist on dansguardian microsoft.com but it looks like it is not enough.</p>
| 0non-cybersec
|
Stackexchange
|
Star Trek Nagios Dashboard. http://www.youtube.com/watch?v=La0kbll6qrk
| 0non-cybersec
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Reddit
|
So I decided to find out exactly which heroes have an audible "low ammo" noise..
| 0non-cybersec
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Reddit
|
javafx ComBobox add listener on selected item value. <p>I need to test the value of a selected item to call different methods, so I write this code adding a listener, but the code generate a syntax error</p>
<pre><code>@FXML
private JFXComboBox<String> cmbComp;
cmbComp.valueProperty().addListener(new ChangeListener<String>() {
public void changed(ObservableValue<String> composant, String oldValue, String newValue) throws SQLException {
if(/*test item value*/){
/*do something*/
}else{
/*do other thing*/
}
}
});
</code></pre>
<p>also I don't need an old value and a new one, just test the selected value, how can'I pass arguments ?</p>
<hr>
<p>I found the error, here is the new code, I hope it helps others</p>
<pre><code>cmbComp.getSelectionModel().selectedItemProperty().addListener( (options, oldValue, newValue) -> {
System.out.println(newValue)
}
);
</code></pre>
| 0non-cybersec
|
Stackexchange
|
Understanding lines in the routing table. <p>Below is my route table where <code>XXX.XX.XX</code> represents part of my public IP. I've been googling for about a week now trying to make OpenVPN work. First I couldn't SSH once running OpenVPN, then I tried using request-level proxies (before realizing that wouldn't be as secure as I'd like), and now I can't access the internet. The command <code>curl -4 https://icanhazip.com</code> results in the error <code>Could not resolve host: icanhazip.com</code>.</p>
<p>Because everything I've read about networking is essentially circular jargon to me, I'm trying to start from the beginning. I'm hoping someone can walk me through the 3 individual cases where each route line would be used.</p>
<pre><code>Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
default XXX.XX.XX.1 0.0.0.0 UG 0 0 0 eth0
10.10.0.0 * 255.255.0.0 U 0 0 0 eth0
XXX.XX.XX.0 * 255.255.240.0 U 0 0 0 eth0
</code></pre>
<p>Here is the route table after I run OpenVPN (and can't connect to the internet). It takes forever for this to load (without running <code>route -n</code>). <code>YYY.YYY.YYY</code> is the broadcast IP. <code>77.234.46.246</code> is the VPN IP address.</p>
<pre><code>Destination Gateway Genmask Flags Metric Ref Use Iface <--new
default YYY.YYY.YYY.1 128.0.0.0 UG 0 0 0 tun0
default XXX.XX.XX.1 0.0.0.0 UG 0 0 0 eth0
10.10.0.0 * 255.255.0.0 U 0 0 0 eth0
77.234.46.246 XXX.XX.XX.1 255.255.255.255 UGH 0 0 0 eth0 <--new
YYY.YYY.YYY.0 * 255.255.255.0 U 0 0 0 tun0 <--new
128.0.0.0 YYY.YYY.YYY.1 128.0.0.0 UG 0 0 0 tun0 <--new
XXX.XX.XX.0 * 255.255.240.0 U 0 0 0 eth0
</code></pre>
<p>So again, I'm looking for examples of when these are utilized (e.g., "when a user tries to access your website...") so I can at least figure out what needs to change in my OpenVPN configuration. <strong>I need my public IP address to be able to receive requests and outgoing requests to go through the VPN without messing up anything else (like SSH) - that's it.</strong> I don't understand how this doesn't come as standard configuration in OpenVPN.</p>
<p>This looks to be the last significant thing on a project I've been working on for months. Please help me move on with my life.</p>
| 0non-cybersec
|
Stackexchange
|
How to declare friend user-defined literal operator within template class?. <p>It is unclear why the code below does not compile with GCC g++ 4.7 telling the following:</p>
<pre><code>$ g++ -std=c++11 -fPIC test.cpp
test.cpp:11:45: error: ‘B operator"" _b(const char*, size_t)’ has invalid argument list
</code></pre>
<p>If class C is declared non-template then it compiles fine.</p>
<pre><code>#include <cstddef>
struct B{};
B operator+(B, B) { return B(); }
B operator"" _b(const char *, size_t) { return B(); }
template<typename T>
class C
{
friend B operator+(B, B);
friend B operator"" _b(const char *, size_t);
};
int main() { return 0; }
</code></pre>
<p>What is wrong with this code? Or is it a compiler bug?</p>
| 0non-cybersec
|
Stackexchange
|
$(\cos 2x + \cos x -1)/(\cos 2x) > 2$ for $x \in <0,\pi>$. <p>Have a trig problem here but it's not coming out right and would appreciate if someone could point out where I've gone wrong.</p>
<p>$$\require{Cancel}\frac{\cos2x + \cos x -1}{\cos 2x} > 2 \\ x \in <0,\pi>$$
First pull out $1$:
$$1 + \frac{\cos x-1}{\cos 2x} >2
\\\\\text {Assume} \\\cos 2x\neq0$$
Next use identity and move $2$ over:
$$1 + \frac{\cos x -1}{2\cos^2x -1} -2 >0$$
Use $t$ instead:
$$\frac{t -1}{2t^2 -1} -1 >0 \\\ \cos x = t$$
Use expansion formula:
$$\frac{t -1}{2(t-1)(t+1)} -1 >0 \\\ \cos x = t$$
Multply both sides to remove fraction:
$$-1 - 2t - 2 > 0$$
Then we have:
$$\cos x<\frac32$$</p>
<p>Not sure where I went wrong.</p>
| 0non-cybersec
|
Stackexchange
|
Calculate the product distribution. <p>Original question was to calculate the $X$, $Y$ and $XY$ distribution, however I have already done the first two, so I am just going to post the question the way I have it.
$$
f_{X,Y}(x,y) = \left\{ \begin{array}{ll}
ye^{-xy-y} & \textrm{when $x>0,y>0$}\\
0 & \textrm{in other case}\\
\end{array} \right.
$$
I calculated both
$$
f_X(x) = \left\{ \begin{array}{ll}
\frac{1}{(x+1)^{2}} & \textrm{when $x>0$}\\
0 & \textrm{in other case}\\
\end{array} \right.
$$
$$
f_Y(y) = \left\{ \begin{array}{ll}
e^{-y} & \textrm{when $y>0$}\\
0 & \textrm{in other case}\\
\end{array} \right.
$$
Since x and y are dependent, i think i can not use the formula given here <a href="https://en.wikipedia.org/wiki/Product_distribution" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Product_distribution</a>, can someone help? </p>
| 0non-cybersec
|
Stackexchange
|
How to use spot instance with amazon elastic beanstalk?. <p>I have one infra that use amazon elastic beanstalk to deploy my application.
I need to scale my app adding some spot instances that EB do not support.</p>
<p>So I create a second autoscaling from a launch configuration with spot instances.
The autoscaling use the same load balancer created by beanstalk.</p>
<p>To up instances with the last version of my app, I copy the user data from the original launch configuration (created with beanstalk) to the launch configuration with spot instances (created by me).</p>
<p>This work fine, but:</p>
<ol>
<li><p>how to update spot instances that have come up from the second autoscaling when the beanstalk update instances managed by him with a new version of the app?</p>
</li>
<li><p>is there another way so easy as, and elegant, to use spot instances and enjoy the benefits of beanstalk?</p>
</li>
</ol>
<p><strong>UPDATE</strong></p>
<p>Elastic Beanstalk add support to spot instance since 2019... see:
<a href="https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html</a></p>
| 0non-cybersec
|
Stackexchange
|
Box of rocks under the Vienna tram seats.
| 0non-cybersec
|
Reddit
|
Closure subspace proof easy, but I am overlooking something. <blockquote>
<p><strong>Theorem</strong>: Let $Y$ be a subspace of $X$; let $A$ be a subset of $Y$; let $\bar{A}$ denote the closure of $A$ in $X$. Then the closure of $A$ in $Y$ equals $\bar{A}\cap Y$.</p>
<p><strong>Proof</strong>: Let $B$ denote the closure of $A$ in $Y$. The set $\bar{A}$ is closed in $X$, so $\bar{A} \cap Y$ is closed in $Y$. Since $\bar{A} \cap Y$ contains $A$, and since by definition $B$ equals the intersection of all closed sets in $Y$ containing $A$, <strong>we must have $B \subset \bar{A} \cap Y$</strong>. On the other hand, we know that $B$ is closed in $Y$. Then $B = C \cap Y$ for some closed set $C$ in $X$. <strong>Then $C$ is a closed set of $X$ containing $A$;</strong> because $\bar{A}$ is the intersection of all such closed sets. Then we have $\bar{A} \cap Y \subset C \cap Y = B.$</p>
</blockquote>
<p>Would someone explain the bolded part to me? I don't understand why $B$ being the smallest closed set containing $A$ in $Y$, implies the inclusion, and just how do we know $C$ contains $A$? Is it because by definition $B$ is in both $C$ <strong>and</strong> $Y$ and by the definition of $B$ we must contain $A$? </p>
<p>Why is it not a good idea to prove $B = B \cup B' = \bar{A} \cap Y$?</p>
| 0non-cybersec
|
Stackexchange
|
Rvest html_table error - Error in out[j + k, ] : subscript out of bounds. <p>I'm somewhat new to scraping with R, but I'm getting an error message that I can't make sense of. My code:</p>
<pre><code> url <- "https://en.wikipedia.org/wiki/California_State_Legislature,_2017%E2%80%9318_session"
leg <- read_html(url)
testdata <- leg %>%
html_nodes('table') %>%
.[6] %>%
html_table()
</code></pre>
<p>To which I get the response:</p>
<blockquote>
<p>Error in out[j + k, ] : subscript out of bounds</p>
</blockquote>
<p>When I swap out html_table with html_text I don't get the error. Any idea what I'm doing wrong? </p>
<p>Thanks!</p>
| 0non-cybersec
|
Stackexchange
|
So I thought I would do a simple project..
| 0non-cybersec
|
Reddit
|
Variable Return Type of a Method in C#. <p>I want to give a parameter to a method and i want my method to return data by looking the parameter. Data can be in type of boolean, string, int or etc. How can i return a variable type from a method? I don't want to return an object type and then cast it to another type. For example:</p>
<pre><code>BlaBla VariableReturnExampleMethod(int a)
{
if (a == 1)
return "Demo";
else if (a == 2)
return 2;
else if (a == 3)
return True;
else
return null;
}
</code></pre>
<p>The reason why i want that is i have a method that reads a selected column of a row from the database. Types of columns are not same but i have to return every column's information.</p>
| 0non-cybersec
|
Stackexchange
|
My best friend has been missing for four years. Two weeks ago, I started getting messages from him.. I fell in love with Silas Wallbank the very first time that I met him \- at least, to the extent that one seven year old boy *can* fall in love with another.
I was the new boy in a class full of kids who had known each other since preschool \- my parents, hippies at heart, had thus far lived a somewhat nomadic life and had homeschooled me while we moved from place to place every few weeks. I had a beautiful childhood, really, but a health scare for my father and a financial blow for both parents shocked them into finally settling down in one place for long enough to make it worth enrolling me in a local school. I remember my first day with painful clarity; the way that the other children had giggled at my unusual name, at my wonky teeth, at my lisp. I remember the sinking feeling of dread that I was to become a target for bullying, that I wouldn’t make any friends.
Then the teacher sent me to go and sit beside Silas.
He was a waifish slip of a child – a head shorter than the other boys and slender to go with it. But he was *beautiful*. With a soft tangle of glossy black hair, alabaster skin, flushed, chubby cheeks and huge dark green eyes, he reminded me of the fairy princess from my mother’s favourite storybook. I told him as much and then blushed, fearing he’d be offended. Instead, he grinned at me, revealing a gap where his front teeth should be, and spoke.
“I like you, Peregrine. Let’s be friends.”
We’ve been best mates ever since. Si grew from an adorable child to an unfairly handsome young man. The baby fat melted away from his face to reveal a sharp jaw and cheekbones which could cut diamonds. He grew out his hair to cascade like a midnight waterfall to the nape of his neck. He hit a growth spurt in his early teens and hit it hard – he ceased to be the tiny, impish boy from our childhood and became a tall, lean teenager, all whipcord muscle and ethereal vampiric beauty. Unsurprisingly, we were often followed around at school and sometimes even on the weekends by a group of flighty girls, who would giggle and whisper behind their hands about Si and swoon every time he smiled in their direction.
With his good looks Si grew an air of effortless classic cool. You know the type that I mean. The type that is characterised by old weather\-beaten leather jackets and sunglasses when it’s not really that sunny out and ratty roll\-up cigarettes. It’s the type of cool that borders on pretentious without really meaning to, and Si is the absolute embodiment of it. Even when we were children, our peers acknowledged that he was special. Everyone was desperate to be his friend. But he only ever seemed to have time for me. Oh, he has a smile and a kind word for everybody and if you get him on to the topic of fantasy novels you’re in for one hell of a good conversation. But rarely do his interactions with other people extend further than that. And with good reason.
Like anyone, Si has skeletons in his closet.
Si’s mother was just 18 years old when she gave birth to her only son. Four years later, she died of a cocaine overdose which was speculated, but not confirmed, to be deliberate. His father – two years his mother’s junior – had been heartbroken, of course. But he’d also been bitter and angry. In his mind, the love of his life had been fine before she had a baby that neither of them had really wanted. In his mind, her death was Si’s fault. It became something of a hobby of his to polish off an entire bottle of whiskey a couple of times a week and subsequently knock seven shades of shit out of his son, just so he’d never forget his mother died because of him.
Naturally, years of this kind of treatment took a mental toll on Si, though nobody else would ever know it. On the nights that his father drank, Si would come to my house, bashed up and bloodied and cry in my arms until he fell asleep. Over the years, I begged him several times to tell someone, or to let me tell them. Terrified of what his father would do to him if he was ever found out, Si refused to go to any kind of authority, and swore me into silence about it as well.
We were 18 years old when Si vanished without a trace.
I saw him on a Saturday night. We were at a party – a friend’s eighteenth birthday – and sharing a joint on a bench in the host’s backyard. Very casually, he told me he was going away for a bit in the morning. I assumed he meant a holiday – maybe a trip to visit his relatives in Wales – and had told him I hoped he had fun. He’d laughed there, and then surprised me by kissing me full on the lips.
“You’ve been such a good friend to me, Rin,” he told me. “I really do love you, mate. I’m gonna miss you.”
Baffled, I told him I loved him too, that missing me was silly when we’d see each other again very soon. There, he’d just given me a sad smile, checked his phone, and told me he needed to go. Watching him leave that party was the last time I – or anybody else for that matter – saw him. He made it home but his father, paralytic drunk, was passed out on the couch and didn’t hear or see his return. When he went to check on him in the morning, he found Si’s room unusually tidy – most of his belongings were gone, and so was he. No note. No indication of where he’d gone or with whom. Just… gone. The police were contacted, of course, but they were entirely unhelpful, stating that they’d put out an announcement that we were looking for him but ultimately, at 18, Si was an adult and he wasn’t considered ‘vulnerable’. He was well within his rights to leave home and go wherever he damn well pleased without letting anybody know.
And that was it. Silas Wallbank had vanished.
I’m 22 now. In the four years that have passed since Si’s disappearance, I’ve done an awful lot of healing. Immediately after he vanished, I’d called and text him several times a day. Left voicemails until his answering machine was full. Sent message after message begging him to let me know he was okay. His phone was always switched on, but he never answered it. I took to trawling local news, searching for reports of missing people – and, later, corpses – that had been found. And nothing.
Eventually, I stopped trying. Panic turned to anger. Maybe the police were right. Maybe he had taken the fuck off and not let anybody know – and that was really shitty and unfair of him to do. I understood wanting to get out of his dad’s place, wanting to lay low so his old man wouldn’t find him. But where was the need in torturing me like this? One day, approximately two and a half years after he vanished, I eventually decided that it was no longer worth putting myself through that kind of mental strain. If Si wanted to ditch me, then fuck him. Shows how much he really cares. I still miss him. Of course I do. When I’m alone in my flat at night, having a beer or a joint and watching one of our old favourite movies, I sometimes like to imagine that he’s there beside me, cracking the same dumb jokes that he always used to. I dream about him sometimes, too. Sometimes they’re good dreams. Sometimes they’re bad dreams. Sometimes they’re nightmares. Aside from that, though, I rarely think too much about him these days.
That is, until two weeks ago, when I started getting some weird text messages.
The first came around midnight on the Saturday. It was from an unknown number, and contained only the bird emoji, four times over. At first, I was confused but wrote it off as some wrong number message. Didn’t seem at all malicious or too weird. An hour or so later, however, I got another message that made my blood run cold;
come on, tweety bird. don’t tell me you’ve forgotten our in\-jokes already.
Si, ever pleased by my aviary first name, had jokingly called me ‘Tweety Bird’ when we were kids and it had stuck as an affectionate nickname ever since. A string of bird emoji had become his way of getting my attention via text. Shaken, I replied fairy quickly, and the following conversation ensued:
Me: I don’t know who the fuck this is, but that’s not fucking funny.
Them: what do u mean u don’t know who it is. it’s silas u fucking tosspot.
Me: Seriously. Not funny. You’re sick.
Them: look. i’m sorry for vanishing. i can explain everything.
Me: I’m blocking this number now.
Them: wait.
The next message I received from the number was a voice message. Playing it just gave me more chills. A voice I’d know anywhere – Si’s voice, clear as day – “now do you believe it’s me, dickhead?”
I immediately tried to call the number, but it was rejected after two rings.
Si: can’t answer calls rn. i can explain everything. but not over text. need to meet u face to face.
Me: Why can’t you answer? Where are you? Has someone done something to you?
Si: i can’t say anything over text, rin. am ok. weird shit happening past 4 years. will meet u @ old library on 31st @ 11pm?
Me: I’ll try to be there.
Si: good. everything will make sense soon.
I’m really scared and confused about all of this. I know I said I’d go to the meeting, but I honestly don’t know if I should. The voice message was definitely Si and the text mannerisms match his but something feels very… wrong about all of this. I’m scared to go to the meeting in case something bad happens, but at the same time, I’d hate to not go and miss out on finding out what’s been going on with him. It's in two days and I still haven't decided. What do I do? Thanks.
[EDIT: UPDATE TO THIS CAN BE FOUND HERE](https://www.reddit.com/r/nosleep/comments/8nwbca/update_my_best_friend_has_been_missing_for_four/)
| 0non-cybersec
|
Reddit
|
How come OSM doesn't like (or offer) bulk downloading of tiles?. <p>On one hand they say that their data is completely free, and you are welcome to use it to create your own tiles from it, and they have no problem in you using their tiles for whatever. On the other hand they say that bulk downloading is "strongly discouraged", even though they also point out that maintaining their servers (for delivery) isn't free, and depends on contributors and sponsorships. </p>
<p>So how come it wouldn't be in their interest to let me download all the tiles, and then host them on my own domain? Also, just ball-parking it, how big would that be anyway, if i were to go up to <code>11</code> zoom, which seems sufficient for my interest.</p>
<p>Relevant document: <a href="https://operations.osmfoundation.org/policies/tiles/" rel="nofollow noreferrer">https://operations.osmfoundation.org/policies/tiles/</a></p>
| 0non-cybersec
|
Stackexchange
|
How can I compare the contents of .pdf files, excluding filenames from comparison?. <p>I usually use WinMerge to view the differences between files, but in this case it doesn't help. The files I'm comparing are known to have different filenames, which is creating false positives when 2 files with the same document inside have different filenames.</p>
<p>I have a folder full of many directories representing all the vendors my company does business with, and they include many .pdf files of receipts & invoices. It's the master vendor list. The invoices & receipts are named such that the names don't make sense without the surrounding directory structure to provide context. For example here we have "Vendors/Company Foo/Product Bar/Invoice#3.pdf"</p>
<p>Then I have another folder with many receipts & invoices in it, that used to be maintained separately from the master vendor list, and was supposed to include a manually-created copy of every receipt & invoice that was entered into the appropriate entry in master vendor directory structure. These receipts & invoices were to have been renamed so they're easier for the accountant to read & know what they refer to. For example here we have "Taxes/CompanyFoo ProductBar.pdf".</p>
<p>I've searched for files of type .pdf in the top-level folder of the master vendor list, so that my search results include receipts & invoices from all the vendors in the directory structure. Then I copied these .pdf files to another folder on my Desktop, so I can compare them. I compared those files to the files in the 'taxes' folder using WinMerge to see if any of the files in the 'taxes' folder don't exist in the 'master vendor' directories, and vice-versa.</p>
<p>But WinMerge counts files as different just because their filenames don't match. I need to know if the file content is different despite what the filename is. </p>
<p>There are hundreds of these files & if any are in the 'taxes' folder that aren't in their corresponding 'master vendor' directory, I need to rectify that & file them correctly.</p>
<p>Can someone recommend a tool that can do this?</p>
| 0non-cybersec
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Stackexchange
|
Bob finally did something for once..
| 0non-cybersec
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Reddit
|
How to prove that this sequence is monotonic?. <p>Given the recursively defined sequence $(x_n)_{n\in\mathbb{N}}\subseteq\mathbb{R}$:</p>
<p>$x_1=1$</p>
<p>$x_{n+1}=1+\frac{1}{x_n}$</p>
<p>How can I prove that $x_{2n-1}\leq x_{2n+1}$ and $x_{2n}\geq x_{2n+2}$ for all natural numbers without $0$ ?</p>
<p>That is, that the sub-sequence of all odd indices is growing and the sub-sequence of all even indices is falling?</p>
| 0non-cybersec
|
Stackexchange
|
Router Disconnecting randomly ! Bad Password?. <p>I have been facing this irritating issue lately, and have exhaustively searched for simmilar issues online but didn't got it solved yet.</p>
<p>I am using a <strong>D-link dual band route</strong>r.These are the present settings of the router::</p>
<ul>
<li>encryption :: WPA 2 AES for both 2.4Ghz and %5Ghz band</li>
<li>Group Key renewal :: set to 36000seconds</li>
<li>IP lease time set for 7 Days</li>
<li>DHCP IP reservation enabled for client (static ips mapped to mac address of clients, in my case just two clients)</li>
<li>Bandwidth fixed to 20 Mhz for both band i.e 5Ghz and 2.4 Ghz
Channels of both 2.4 Ghz and 5Ghz set to manual, to avoid interference with other (also interference ruled out by wifi analyser app) infrastructural wifi networks
Multicast disabled</li>
</ul>
<p>All other settings are default.</p>
<p>The router receives internet connection through a ethernet connection.</p>
<p>For the <strong>client side</strong> (my laptop) :</p>
<ul>
<li>OS :: linux 16.04</li>
<li>network manager :: wicd</li>
<li>ipv6 disabled</li>
<li>Encryption :: WPA 1/2 (Hex[0-9/A-F])</li>
<li>wicd is configured to only this network</li>
</ul>
<p>I am using a tp link usb wifi adapter to connect to network. Power management turned off, ipv6 disabled.</p>
<p><strong>Problem</strong> :: the connection to network (either of the bands 2.4Ghz and 5Ghz is not stable. SOmetimes it remains connected for 40 50 mins but disconnects suddenly. Once disconnected it won't reconnect for 15-20 mins, but if I restart the router it will immediately reconnect.At wicd side even when the link strength is 80-100% (also in iwonfig) the connection does not gets established once disconnected, it also shows message "bad password".</p>
<p>Also as per 'dmesg' whenever it disconnects I can observe that it throws a "sta recv deauth reason code(6)" followed by code(2) and code(3) repeatedly multiple times.</p>
<p>At the router side I don't know how to get logs.</p>
<p>Interestingly, my laptop very smoothly connects to university network and is very stable even with poor link strength.</p>
<p>Please help me I have been struggling a lot past month.</p>
| 0non-cybersec
|
Stackexchange
|
browserify bundle electron app main process file. <p>I am building a electron app and currently using browserify for the renderer (web page) files like any other javascript front end. I would like to also use browserify to bundle the main process files. However, browswerify is unable to find the electron built in modules like clipboard, ipc, browser-window, app, etc...</p>
<p>In my main.js file which serves as the entry point for the electron app. I have:</p>
<pre><code>const ipc = require('ipc');
const clipboard = require('clipboard');
const BrowserWindow = require('browser-window');
const app = require('app');
const yargs = require('yargs');
</code></pre>
<p>the const yargs loads fine as it is in the node_modeuls folder and browserify can resolve that. However the othe four items cannot be found by browserify and therefore fail my build.</p>
<pre><code>[11:49:17] Finished 'development' after 17 ms
Error: Cannot find module 'ipc' from '<path>'
Error: Cannot find module 'clipboard' from '<path>'
Error: Cannot find module 'browser-window' from '<path>'
Error: Cannot find module 'app' from '<path>'
</code></pre>
<p>Any suggestions?</p>
| 0non-cybersec
|
Stackexchange
|
Non-Homogenous Secord Order DE w/ constant coefficients. <p>I am getting stuck on finding a particular solution to the equation:</p>
<p>$y''-6y'+9y=(x+1)e^{3x}$</p>
<p>I know the general solution must be of the form $y_g=y_p+y_h$ </p>
<p>I fround the corresponding homogeneous solution to be $y_h=c_1e^{3x}+c_2xe^{3x}$ and I am stuck trying to find a particular solution $y_p$.
The method that should be used is the method of undetermined coefficients, and I have attempted solutions of the form $Axe^x, Ae^x+(Bx+c)e^{3x}$, and actually a few others to no avail. If someone could tell me the solution and $how$ they determined what form was necessary for the particular solution I would be much obliged.</p>
| 0non-cybersec
|
Stackexchange
|
Mythbusters takes a swing at Star Wars.
| 0non-cybersec
|
Reddit
|
Let's get to work.
| 0non-cybersec
|
Reddit
|
Simply connected 3-manifolds are homotopy equivalent to 3-spheres. <p>Let $M$ be a simply connected $3$-dimensional manifold (smooth, closed, connected). How to prove that $M$ has a homotopy type of a $3$-sphere?
I would like to use somehow Whitehead theorem: so the problem reduces to show the <em>weak</em> homotopy equivalence (i.e. the existence of a map $f:M \to S^3$ inducing isomorphisms on every homotopy group). </p>
| 0non-cybersec
|
Stackexchange
|
What is the difference between babel-plugin-* and babel-preset-*. <p>I am using both plugin and preset and my current react app but technically I am not able to make someone understand what is difference between preset and plugins. For me both are the javascript file which used by babel loader to compile the code.</p>
| 0non-cybersec
|
Stackexchange
|
How to set up PHP-FPM on Apache?. <p>I have a server with Ubuntu 18.04 and PHP 7.2</p>
<p>My site is with Drupal 8</p>
<p>How to set up PHP-FPM on Apache?</p>
<p>I find only tutorial for NGINX or are outdated.</p>
| 0non-cybersec
|
Stackexchange
|
To fix it.
| 0non-cybersec
|
Reddit
|
Determine if vectors are linearly independent. <p>Determine if the following set of vectors is linearly independent:</p>
<p>$$\left[\begin{array}{r}2\\2\\0\end{array}\right],\left[\begin{array}{r}1\\-1\\1\end{array}\right],\left[\begin{array}{r}4\\2\\-2\end{array}\right]$$</p>
<p>I've done the following system of equations, and I think I did it right... It's been such a long time since I did this sort of thing...</p>
<p>Assume the following:
\begin{equation*}
a\left[\begin{array}{r}2\\2\\0\end{array}\right]+b\left[\begin{array}{r}1\\-1\\1\end{array}\right]+c\left[\begin{array}{r}4\\2\\-2\end{array}\right]=\left[\begin{array}{r}0\\0\\0\end{array}\right]
\end{equation*}
Determine if $a=b=c=0$:
\begin{align}
2a+b+4c&=0&&(1)\\
2a-b+2c&=0&&(2)\\
b-2c&=0&&(3)
\end{align}
Subtract $(2)$ from $(1)$:
\begin{align}
b+c&=0&&(4)\\
b-2c&=0&&(5)
\end{align}
Substitute $(5)$ into $(4)$, we get $c=0$.</p>
<p>So now what do I do with this fact? I'm tempted to say that only $c=0$, and $a$ and $b$ can be something else, but I don't trust that my intuition is right.</p>
| 0non-cybersec
|
Stackexchange
|
[Homemade] Mango fried rice with Jerk Chicken.
| 0non-cybersec
|
Reddit
|
The Inebriator - Arduino Programmable Cocktail Making Machine! (x-post from r/videos).
| 0non-cybersec
|
Reddit
|
How to use spot instance with amazon elastic beanstalk?. <p>I have one infra that use amazon elastic beanstalk to deploy my application.
I need to scale my app adding some spot instances that EB do not support.</p>
<p>So I create a second autoscaling from a launch configuration with spot instances.
The autoscaling use the same load balancer created by beanstalk.</p>
<p>To up instances with the last version of my app, I copy the user data from the original launch configuration (created with beanstalk) to the launch configuration with spot instances (created by me).</p>
<p>This work fine, but:</p>
<ol>
<li><p>how to update spot instances that have come up from the second autoscaling when the beanstalk update instances managed by him with a new version of the app?</p>
</li>
<li><p>is there another way so easy as, and elegant, to use spot instances and enjoy the benefits of beanstalk?</p>
</li>
</ol>
<p><strong>UPDATE</strong></p>
<p>Elastic Beanstalk add support to spot instance since 2019... see:
<a href="https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html</a></p>
| 0non-cybersec
|
Stackexchange
|
Seeds?. Should I use the seeds from my hermie plant to start over or find something online? The pollen came from a nearby hemp field.
| 0non-cybersec
|
Reddit
|
Why am I able to open Wireshark and capture packets in macOS without root privileges?. <p>As far as I know, capturing packets using Wireshark requires root/administrator privileges. In Windows, it prompts for UAC elevation and runs with administrative privileges. The same thing in Ubuntu; it prompts for a password to authorize access before showing me the interfaces. </p>
<p>However, in macOS, there is no authorization required. I don't have to enter a password. Instead, Wireshark is directly showing me the interfaces and I am able to capture packets.</p>
<p>How is Wireshark able to do this on macOS? What is special about macOS that allows interfaces and packets to be monitored <em>without</em> administrative access?</p>
| 0non-cybersec
|
Stackexchange
|
Problem involving explicit solutions for differentials. <p>Hi so this is the problem I am trying to work out</p>
<blockquote>
<p>Find an explicit solution for $xy′ = e−y$, for $y(1) = 1$</p>
</blockquote>
<p>I worked it through to find the anti-derivative and ended up getting
y = ln(lnx +C), I went on to find C which was e^1. However I am not too sure if did the anti-derivative correctly and what it means by explicit solution. If anyone can break it down and explain that would be great :).
Thanks</p>
| 0non-cybersec
|
Stackexchange
|
I picked up Everyday Shooter for the PS3, and my mind=blown. If you like your video games with herbal enhancement, this will provide you with hours of entertainment..
| 0non-cybersec
|
Reddit
|
How to delete the old backup differencial files?. <p>I'm (trying) managing a large number of sql server instances among a number of machinces running SQL Server 2005 and 2008. Almost all the DB are in Simple Recovery Model.
I'm doing full backups every Sunday and differencial backups every day.
Even though I am using compressed backups, there are databases which are nearly a TB. Therefore, I need to have a proper use of the backups regarding the space they are allocating.</p>
<p>My goal: I just need to have one full and one differencial backup for each database every single moment.</p>
<p>My question : What actions should I perform in order to achieve my goal? I guess something i need to do with the expiration of the backups and the "Clean up history", but I am not sure what exactly i need to do.</p>
| 0non-cybersec
|
Stackexchange
|
How to use spot instance with amazon elastic beanstalk?. <p>I have one infra that use amazon elastic beanstalk to deploy my application.
I need to scale my app adding some spot instances that EB do not support.</p>
<p>So I create a second autoscaling from a launch configuration with spot instances.
The autoscaling use the same load balancer created by beanstalk.</p>
<p>To up instances with the last version of my app, I copy the user data from the original launch configuration (created with beanstalk) to the launch configuration with spot instances (created by me).</p>
<p>This work fine, but:</p>
<ol>
<li><p>how to update spot instances that have come up from the second autoscaling when the beanstalk update instances managed by him with a new version of the app?</p>
</li>
<li><p>is there another way so easy as, and elegant, to use spot instances and enjoy the benefits of beanstalk?</p>
</li>
</ol>
<p><strong>UPDATE</strong></p>
<p>Elastic Beanstalk add support to spot instance since 2019... see:
<a href="https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html" rel="nofollow noreferrer">https://docs.aws.amazon.com/elasticbeanstalk/latest/relnotes/release-2019-11-25-spot.html</a></p>
| 0non-cybersec
|
Stackexchange
|
RNFS.exists() always returns TRUE.
<p>I am using react-native-fs and for some reason whenever I use the exists() method it is always returning as TRUE. A sample of my code looks like this:</p>
<pre class="lang-js prettyprint-override"><code>let path_name = RNFS.DocumentDirectoryPath + "/userdata/settings.json";
if (RNFS.exists(path_name)){
console.log("FILE EXISTS")
file = await RNFS.readFile(path_name)
console.log(file)
console.log("DONE")
}
else {
console.log("FILE DOES NOT EXIST")
}
</code></pre>
<p>The output at the console is "FILE EXISTS", then an error is thrown that says:</p>
<blockquote>
<p>Error: ENOENT: no such file or directory, open
/data/data/com.test7/files/userdata/settings.json'</p>
</blockquote>
<p>How can it exist using the <code>exists</code> method, but not the <code>readFile</code> method?</p>
<p>On further checking it seems that RNFS.exists() is always returning true, no matter what the filename is. Why is it always returning true?</p>
<p>A display of path_name says <code>/data/data/com.test7/files/userdata/settings.json</code>.</p>
<p>Even if I change my code to something nonsensical like the following code:</p>
<pre class="lang-js prettyprint-override"><code>if (RNFS.exists("blah")){
console.log("BLAH EXISTS");
} else {
console.log("BLAH DOES NOT EXIST");
}
</code></pre>
<p>It still evaluates to true and displays the message:</p>
<pre class="lang-js prettyprint-override"><code>BLAH EXISTS
</code></pre>
<p>I have displayed the contents of the directory and verified these files do not exist.</p>
| 0non-cybersec
|
Stackexchange
|
Why use HTTPS Everywhere instead of going to the HTTPS site directly?. <p>My understanding is that HTTPS Everywhere redirects websites to an https:// version if they support it.</p>
<p>My question is, if websites do have an https:// supported version why aren't they using them in the first place?</p>
| 0non-cybersec
|
Stackexchange
|
A subset of $\mathbb{N}$ is finite if and only if it has a maximum element. <p>I have been stumped on both directions of the proof for quite some time now.</p>
<p>For the forward direction, I initially naively thought I could use the definition of finite (bijection <span class="math-container">$f: S \rightarrow [m] $</span> for some <span class="math-container">$m \in \mathbb{N}$</span>, and some subset of <span class="math-container">$S\subseteq\mathbb{N}$</span>) and declare <span class="math-container">$f^{-1}(m)$</span> to be the greatest element; I can't because the bijection does not guarantee the mapping in order.</p>
<p>I have thought about using a recursive definition but I feel like there is another easier way to go about doing this with maybe composition of functions?</p>
<p>Any suggestions and advice?</p>
| 0non-cybersec
|
Stackexchange
|
How to create Android Google Play's Grid View like Widget with different size images loaded dynamically. <p><img src="https://i.stack.imgur.com/aZkGv.jpg" alt="enter image description here"></p>
<p><img src="https://i.stack.imgur.com/ENpAk.png" alt="enter image description here"> </p>
<p>Hi<br/>
I have enclosed two app images which has grid view like widgets with different image heights and widths, loaded dynamically ,i need to create the same type of UI ,i could be glad if someone guide me to start with. </p>
| 0non-cybersec
|
Stackexchange
|
What iPhone apps are available for sending bulk SMSs?. <p>What iPhone apps can I use for sending bulk SMSs?</p>
<p>Hopefully something very simple to get started with....</p>
| 0non-cybersec
|
Stackexchange
|
I hate not knowing if it's mutual. I hate who I become when I like someone.. Anyone else feel this way?
I was considering writing about the person I currently like and how it's affecting me and advice for it but when I ever think I'm only gonna write a paragraph about someone I like I end up writing an entire essay and i'm like holy shit no one is gonna read this shit lol.
So instead I'd rather focus on the more generic root of the problem. It seems like when ever I'm interested in someone I just get depressed or sad. Even when they show interest. I just keep finding reasons in my head that it's not real. Or why bother I'm just gonna mess it up. Or she's just using me for attention. Or I'm gonna waste all this time just for it to end. I guess I had a lot of bad experiences growing up and while I'm still a bit better at this stuff I still suck. I've just had so many experiences where shit seems amazing and it then it's over. So why bother letting my guard down? Is this mentality just making me become my own self defeating prophecy at this point? Has anyone ever been able to overcome this feeling?
I think personally I just can't handle another heart break so I keep looking for excuses to save myself. I may be strong as heck physically but when it comes to this love stuff. I'm weak. How can I be stronger? Or should I just stay in my shell and accept being alone? I just want to overcome this feeling and be confident in love again. I miss being a young teenager when I was dumb and naive. I'm 25 and male if that's important btw.
| 0non-cybersec
|
Reddit
|
A man helps a cat get a drink of water in Mecca.
| 0non-cybersec
|
Reddit
|
EAZ bosses should count as multiple minibosses. Please either make bosses count as 5 minibosses or swap the requirements to kill 50 minibosses and loot 100 chest. Everyone keeps leaving after summoning the boss and then people just get backfilled and leave.
| 0non-cybersec
|
Reddit
|
Set all measurable real functions on $[0,1]$ with metric $\int_{0}^1 \min \{1,|f(t)−g(t)|\}dt$ is Fréchet without nonzero continuous linear functional. <p><strong>Bounty Edit:</strong> <em>In the following, all the questions will be highlighted by a bold number and a text written in italics.</em></p>
<p>I found the following statement in a book, and I am really struggling to see why it is true.</p>
<blockquote>
<p><em>The set of all measurable real functions on $[0,1]$, metrized via the map $$(f,g)\mapsto \int_{0}^1 \min \{1,|f(t)−g(t)|\}dt,$$ is a Fréchet space on which there is no nonzero continuous linear functional. (Even the linear functional $f\mapsto f(0)$ is not continuous on this space).</em></p>
</blockquote>
<hr>
<p>Regarding the very last statement in braces, I should have a proof of it.</p>
<blockquote>
<p><em>Attempted Proof:</em><br>
Let $f=0$, i.e. for every $x \in [0,1], f(x) = 0$, and define $f_n$ as
$$ f_n (x):=
\begin{cases}
1, & \text{ if } x \in [0, \frac{1}{n}],\\
0, & \text{ if } x \in (\frac{1}{n}, 1].\\
\end{cases}$$
To see that $f_n \to f$, notice that, for an arbitrary $n \in \mathbb{N}$, we have
$$ \begin{align*} d(f_n , f) &= \int_{0}^1 | f_n (t) - f(t) | \ dt \\
&\leq \int_{0}^1 | f_n (t)| + |f(t) | \ dt \\
&= \int_{0}^1 | f_n (t)|\ dt + \int_{0}^1 |f(t) | \ dt \\
&= \int_{0}^1 | f_n (t)|\ dt \to 0 \end{align*} $$
However, $f_n(0) \nrightarrow f(0)$, because for every $n \in \mathbb{N}$, $f_n (0) =1$, while $f(0)=0$.</p>
</blockquote>
<p>Concerning it, here there is my <strong>first question</strong>:</p>
<p><strong>1)</strong> <em>Is the way in which I wrote the proof correct?</em></p>
<hr>
<p>Regarding the main statement, the things that have to be proved are two:</p>
<p>a) $\mathcal{M}$ (that denotes the set of all measurable functions on $[0,1]$) is a Frechét space (complete metric linear space);<br>
b) there are no nonzero continuous linear functionals on $\mathcal{M}$. </p>
<p>Related to part (b) I found in Rudin's "Functional Analysis" (pp.36-37, section 1.47) a proof that the space $L^p$
with $0 < p <1$ behaves in the same way. Moreover, on the <a href="https://en.wikipedia.org/wiki/Locally_convex_topological_vector_space" rel="nofollow">wikipedia page on locally convex TVS</a> I found that there is still another space that behaves similarly, namely $L_0$, i.e. the set of all measurable functions with distance function $$d(f,g):= \int_{0}^1 \frac{|f(x) - g(x)|}{1+|f(x)-g(x)|}dx.$$</p>
<hr>
<p>Thus, here there are my <strong>other questions</strong>.</p>
<p><strong>2)</strong> <em>Is it possible to prove part (a) in different ways, namely one less constructive, and another one more constructive, with an actual $f \in \mathcal{M}$ to which an arbitrary Cauchy sequence $(f_n) \subseteq \mathcal{M}$ converge? If yes, how?</em></p>
<p><strong>3)</strong> <em>Is it possible to prove part (b) by showing that $\mathcal{M}$ is homeomorphic to $L_0$, which is homeomorphic to $L^p$ with $0 < p <1$, and then exploiting Rudin's proof? Are all those spaces actually homeomorphic? If yes, how?</em></p>
<p><strong>4)</strong> <em>If they are not homeomorphic, and we cannot use Rudin's proof, essentially, how do we prove the result, namely part (a) and part (b)?</em></p>
<hr>
<p>I am looking forward to any answer, because being self-thaught I am having some real problems concerning this result, and I have the feeling that grasping this proof (with the techniques involved) would help me a lot.</p>
<p>Thank you for your time. </p>
| 0non-cybersec
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Stackexchange
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Is it possible to have $D=\Bbb P$. <p>Let $f:\Bbb R\to \Bbb R$ and $D=\{x\in \Bbb R: f $ is discontinuous at $x\}$.</p>
<p>My problem is : Is it possible to have $D=\Bbb P$ where $\Bbb P$ is the set of irrationals in $\Bbb R$.</p>
<p>I know the answer is negative, but, how to prove it??</p>
<p>My attempt: First, I proved that $\Bbb P$ is not a countable union of closed sets in $\Bbb R$.Then, I read somewhere that $D$ is an $F_{\sigma}$ set (but don't know how to prove it).</p>
<p>If one could prove the second part, the problem is solved, but How to do it??
Thanks in advance!!</p>
| 0non-cybersec
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Stackexchange
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Centered prime squared in a triple of primes which divides the sum of the three primes squared. <p>Let be <span class="math-container">$p_k$</span>, <span class="math-container">$p_{k+2}$</span> and <span class="math-container">$p_{k+4}$</span> three primes</p>
<p>Now consider this example:</p>
<p><span class="math-container">$5^2$</span> divides <span class="math-container">$2^2+5^2+11^2$</span>.</p>
<p>I ask for for primes <span class="math-container">$(p_{k+2})^2$</span> dividing the following sum:</p>
<p><span class="math-container">$(p_k)^2$</span>+<span class="math-container">$(p_{k+2})^2$</span>+<span class="math-container">$(p_{k+4})^2$</span>.</p>
<p>Are there infinitely many solutions?</p>
| 0non-cybersec
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Stackexchange
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DKIM is not Failing When Messages Come From Another Domain. <p>Somebody sent out spam messages with a forged <code>From:</code> address, so that the messages appeared to come from us. The headers clearly show otherwise. We have DKIM and SPF set up. The problem is that in the bounce messages that came to us, I noticed this line:</p>
<pre><code>Authentication-Results: mta1097.sbc.mail.bf1.yahoo.com from=mydomain.org; domainkeys=neutral (no sig); from=mydomain.org; dkim=neutral (no sig)
</code></pre>
<p>I believe that this should say <code>dkim=fail</code>, which should cause all such messages to bounce. Instead, many were delivered. If it's relevant, when we do send messages through our server, DKIM passes. Is there a setting that can be changed in OpenDKIM to fix this?</p>
| 0non-cybersec
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Stackexchange
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SQLAlchemy introspection of declarative classes. <p>I'm writing a small sqlalchemy shim to export data from a MySQL database with some lightweight data transformations—mostly changing field names. My current script works fine but requires me to essentially describe my model twice—once in the class declaration and once as a list of field names to iterate over. </p>
<p>I'm trying to figure out how to use introspection to identify properties on row-objects that are column accessors. The following works almost perfectly: </p>
<pre><code>for attr, value in self.__class__.__dict__.iteritems():
if isinstance(value, sqlalchemy.orm.attributes.InstrumentedAttribute):
self.__class__._columns.append(attr)
</code></pre>
<p>except that my to-many relation accessors are also instances of sqlalchemy.orm.attributes.InstrumentedAttribute, and I need to skip those. Is there any way to distinguish between the two while I am inspecting the class dictionary?</p>
<p>Most of the documentation I'm finding on sqlalchemy introspection involves looking at metadata.table, but since I'm renaming columns, that data isn't trivially mappable. </p>
| 0non-cybersec
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Stackexchange
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