Are there standards for Bridge robots

Question: I'm thinking of building a bridge robot that bids and plays a hand.  Are there any standards for robots to play against each other?
Comment: You are ***very late*** to the party - competent programs have been available for over 5 years, and good ones are currently available. There have even been Computer Bridge World Championships foe several years: http://greatbridgelinks.com/gblsoft/.
Comment: Thanks for the info, but I am looking for a standard/protocol to have multiple robots to play against each other.
Answer: Under the conditions of contest for ACBL/WBF sponsored World Computer Bridge Championships Section VI. Method of Play the use of a Table Manager is mandated, of which two examples are mentioned by name:

Table Manager
One copy of each robot will be played on a computer.  Exception can be made to allow two copies of each program (a pair) to be played on one computer.
Matches will be controlled by a Table Manager program.  One that may be used Bridge Monitor, developed by Gerard Joyez, or a Table Manager developed by Ian Trackman of Blue Chip Bridge Ltd.  The latter program is the property of Blue Chip Bridge Ltd which has full copyright and other intellectual property rights to it.  If it is used it will be supplied to acceptable potential contestants solely for the purpose of preparing for the Montreal competition.  To receive a copy an entrant must agree to the above restrictions, abide by the copyright, agree not distribute the program, and sign a release statement provided by Blue Chip Bridge, Ltd.
Transmission of information as to deals, bids and play of cards and otherwise, will be consistent with the protocol defined on http://www.bluechipbridge.co.uk/protocol.htm.
Programs must not communicate with their "partner" program or any other program nor search for any information.  Any attempt to do so will be deemed to be a violation of the rules.  The penalty is disqualification.  The ACBL reserves the right to implement whatever network monitoring and/or other measures that it thinks fit without disclosure to the participants.

Under these conditions of contest, the protocol defined at http://www.bluechipbridge.co.uk/protocol.htm has been a de facto standard since 2005:

Introductory
2. The basic concept is that there are five programs, ideally running on five separate computers.  One program plays for each hand. The fifth program acts as the "Table Manager". The Table Manager's function is to deal the cards, transmit and receive all communications among the playing programs, keep the score and (to a limited extent) enforce the rules of the game.
3. All communications are in plain-text ASCII format (characters #10, #13 and #32 to #127 only), using TCP/IP. It has been suggested that all 8-bit ASCII characters should be allowed for e.g. accented characters, but this might cause display problems for receiving computers (opinions please).
....
10. Most messages are in plain English, so that the transmissions will be intelligible to operators and observers without decoding.
Connecting
1. To connect with the Table Manager, a player opens a client socket to the Table Manager's computer.  The player sends "Connecting ["team name"] as [Hand] using protocol version [x]".  The team-name should be enclosed in double-quotation marks (ASCII #34) to avoid any conflict with reserved words used in this protocol.  So that the team-name can be used as part of a file-name for hand records etc., it should consist only of characters which would be valid as part of a file-name. ....
Comment: From the various links you provided, I've created documentation for the Table Manager messages.  See https://unpkg.com/table-master-parser/dist/doc/index.html

Are there standards for Bridge robots


Analytic gradient for DLPNO-CCSD

Question: Is there a formula for analytical gradients (for geometry optimization) for the DLPNO-CCSD method? I ask because I know that it is not implemented in ORCA. Maybe PNO-CCSD is implemented in MRCC or MOLPRO.
Comment: I guess the answer is that geometry optimization can be done with DFT or DLPNO-MP2, so why do it with DLPNO-CCSD? I'm sure it can be implemented if someone really wants it, but it might not give better geometries than DFT or DLPNO-MP2. Sure CCSD can be more accurate than MP2, but the optimized geometry will involve so many approximations (e.g. DLPNO approximation, and small basis set since DLPNO would never be used with a big basis set) that there may be no value in using CCSD.
Comment: @NikeDattani - there are already several papers using DLPNO-CCSD(T) with basis set extrapolations. Sure, probably not 5Z or 6Z basis sets, but for medium-sized molecules, DLPNO-CCSD(T) with basis set extrapolation is tractable, so why not do a 2Z / 3Z or 2, 3, 4 extrapolation and remove basis set effects?
Comment: As to using DLPNO-CCSD(T) for geometry optimization or frequencies, it's clearly interesting, but it's not trivial. Neese is still a bit unsure about implementing polarizabilities.
Comment: @GeoffHutchison There's no doubt that DLPNO-CCSD(T) can be done with 3Z/4Z then extrapolated to the CBS limit. I can see the use in that for single-point energies; but for geometry optimization it seems like overkill! It would mean quite a lot of DLPNO-CCSD calculations with at least 3Z, and the resulting geometry is not guaranteed to be any closer to the "true" geometry than a good MP2 or DFT geometry. To get the "true" geometry we'd need to also properly account for things like Born-Oppenheimer breakdown and relativity: Doing FCI without fixing the rest isn't guaranteed to be more accurate.
Comment: @NikeDattani geometry optimization is available for canonical CCSD method in Gaussian. Thus, there is obvious motivation to do DLPNO-CCSD geometry opt if people do use canonical CCSD for geometry opt.
Comment: I would be a lot more careful with the word "obvious". It makes sense that geometry optimization was implemented for CCSD, but now that we know that CCSD geometries are not much better than MP2 or DFT geometries, it's not as important to implement geometry optimization at CCSD level anymore. MP2 and DFT are usually enough.
Comment: @NikeDattani I agree that "obvious" should be used more cautiously. I personally don't have many experience on running geometry optimization for large molecular systems but I think only people in application of these method are qualified to judge if CC level geometry opt is necessary.
Answer: Note that the DLPNO method is only implemented in ORCA. There are indeed analogous and similarly efficient and accurate methods, the PNO-LCCSD method in Molpro [doi.org/10.1021/acs.jctc.7b00799] and the LNO-CCSD method in MRCC [doi.org/10.1021/acs.jctc.9b00511].
To my knowledge exact analytical gradients are not implemented for either of them. There is an impressive implementation for analytical DLPNO-MP2 gradient in ORCA [https://doi.org/10.1063/1.5086544] and a first derivative for DLPNO-CCSD with respect to electric field components [http://dx.doi.org/10.1063/1.4962369].
So far it is not completely clear what kind of applications would benefit from the significantly higher cost of local CCSD or CCSD(T) gradients compared to, e.g., DFT, we will see.
Answer: As far as I know, analytic gradients for DLPNO-CCSD are not available in ORCA. Analytic first derivatives are available for both closed-shell and high-spin open-shell cases, which could be used for computing other first-order properties.
As the first exercise to implement analytic gradients within the DLPNO setup, the DLPNO-MP2 method was considered and the additional steps to implement gradients, especially those related to orbital response contributions, were carefully analysed.
It is indeed not clear whether or not it is worthwhile to use DLPNO-CC for geometry optimization, while there are cheaper and more efficient DFT methods for this purpose.
Comment: I wouldn't say that MP2 is comparable to DFT, because DFT can be more accurate or less accurate. CCSD(T) is less and less often called the "gold standard". CCSD(T) is great for single-point energies of single-reference systems, but I wouldn't call it the "gold standard" for geometry optimization. I most often see geometries obtained at DFT or MP2 level. DLPNO-CC is a lot older than 4 years, and there's also PNO-LCC and LNO-CCSD which can be the same or better. The PNO idea has been around for decades. DFT can be better than CC, e.g. transition metal complexes where Frank Neese chooses B3LYP.
Comment: Welcome to our site!
Comment: I tag geometry optimization in this question but the question itself is not limited to geometry optimization. Before the development of linear scaling DLPNO, coupled clusters is extremely expensive and single point calculations is only feasible in most cases. However, since we have linear scaling CC method and single point calculations are not satisfactory for many applications, if analytical gradient of DLPNO method is implemented, we could do ab initio MD which is really powerful. Consider if we could have dynamic simulations of bio-systems with CC level accuracy, it is going to be seminal .
Comment: Another important aspect is simulation of high resolution spectra, once analytical gradient is available, one could evaluate numerical hessian which is associated with frequencies. And I don't think DFT level frequency calculation is accurate enough in many cases.
Comment: @PaulieBao Analytic gradients exist for DLPNO-MP2, but has anyone done AIMD with it?
Comment: @NikeDattani the accuracy of MP2 is comparable to DFT while CC is the golden standard in electronic structure. It is not universally accepted to the material modeling community might just because the DLPNO-CC approach is a very new approach ( in less the 4 years). If the community know that there is linear scaling CC approach available, no one will use DFT any more.

Analytic gradient for DLPNO-CCSD


How do they shoot fight scenes without causing harm to performers?

Question: What are the techniques to create a realistic fight/combat scene without injuring the actors?
Comment: I was going to answer by referencing original Star Trek fight scenes, but then I realized we were talking about realistic scenes. We use to love how they wouldn't even try to get the stunt men to resemble the actors, beyond the matching uniform shirt.
Answer: The fight is shoot in many small pieces,in movies you can see how camera always changes many positions during fight scenes.
The camera position faces so that the fist blocks the view of impact,actors keep the distance between them so actually there is no real contact between them,the sound and the impact effects are added later on.Each scene is reviewed to make sure that actor that gets hitted timed accordingly to the first actor that is hitting him so that it looks believable to a viewer.
Also actors can perform parts of the fight in slow motion to make the best timed hits and other complicated awesome moves,it is edited and fixed later on so it looks like real time.
In movies like matrix with longer and steady camera scenes the fight requires a lot of choreography from actors and from the cameraman and it includes a lot of extras and ropes.
Answer: The moves are all scripted, I believe; so every actor knows which hits are coming up next and it's not a surprise...unless it's improvised like a slap or something (in which case that is totally real).
Answer: stunt men for the bigger action bits. Then, after they're on the ground and wounded, having just jumped down a few stories, put in the 'realies' (the actual actors, the faces people paid to see), put blood on them and shoot them standing up and talking. It's all choreographed, rehearsed and well-worked out. Action actors know how to throw and take a punch. Some, like Keannu Reeves are very skilled athletes, have a coterie of stunt men they trust, and will do things themselves when possible.
Answer: For the old John Wayne fights, they coordinated a swung punch just missing with the recipient moving their head quickly as if they were hit. Sound effects fill the credibility gap.
Sometimes in comedy shows, the person being hit will move their head the wrong way.
In modern digital action scenes, there can be wires, harness and such which are removed from the image later.
Also an actors face can be digitally added to a stunt performer. In Titanic, in the scene where our heroes run away from the gushing water, there was digital face replacement.
Whenever characters run from an explosion or fireball, it is always chromakey. It's actually easier to do it that way as well as safer.
Don't forget, there is such a complex set of insurance, Producers can't put a star at risk without the insurance company approving, otherwise a dead or injured star costing a hundred million or more might come out of the Producers own pocket. Double ouch!


Can anyone explain the idea of anodic nerve stimulation?

Question: Nerves get stimulated under the cathode, according to the conventional current direction. But in some research, it is said that anodic stimulation or anodic current stimulation can activate neurons. How does it occur physically? The picture below shows the two types of stimulation, but I can't get it.
Answer: Short answer
Both anodic and cathodic current pulses can evoke neural activity, as shown in your image.
Background
You have to be aware that the current direction is arbitrary and the 'convention' you mention depends on your discipline. In electrophysiology, the anode is generally considered to be the positive electrode, the cathode is generally the negative electrode and the anode the positive. In physics however, current is assumed to be positive (due to historical reasons) and therefore the definition of anode and cathode is opposite.
Secondly, there is no reason to assume that nerves under the cathode are stimulated (and not under the anode), as is shown in your picture - in both cases a neural response is elicited. For example in cochlear implants, biphasic current pulses are used, because these are safer than simple anodic or cathodic pulses. Biphasic pulses are charge balanced and consist of an anodic phase and an opposite cathodic phase. (Cochlear implants are arrays of electroides implanted in the inner ear that stimulate the auditory nerve directly and are used to treat sensorineural deafness).
In animals and humans, both anodic and cathodic pulses can evoke neural responses. In human cochlear implant users, the anodic phase is more effective than the cathodic phase. In contrast, in animals usually the opposite is observed. The reason for this discrepancy is unclear (Machery & Cazals, 2016).
Whatever the exact reason of their differing effectivity in evoking neural activation - both anodic and cathodic current pulses can evoke neural activity.
Reference
- Machery & Cazals, Adv Exp Med Biol (2016); 894:133-42
Answer: In both cases you generate loops of current, with current densities determined by the overall conductive geometry. So a current flowing from the cathode (negative electrode in electrophysiology), and thus imposing negative charges onto the outer surface of an apposed neuronal membrane, would create a local depolarization there, but would also at a distance draw negative charges away from the outer surface of the membrane, albeit with a lower current density, thus creating a local and weaker hyperpolarization there. Now, consider what happens when you switch to an anode. Current flowing from the anode would impose positive charges onto the outer surface of an apposed neuronal membrane, creating a local hyperpolarization there. But it would also draw positive charges away from the outer surface of the membrane at a distance, creating a local and weaker depolarization there. Crank up the current and you can make that depolarization at a distance strong enough to reach threshold. You would thus excite the membrane at that point, despite hyperpolarizing the membrane closer to the anode.
Because the conductive geometry of biological tissue, and thus the current loop pathways, can be quite complex, the effectiveness of cathodal versus anodal stimulation can vary and be hard to predict. Thus, one usually ends up choosing one over the other on purely empirical grounds.
Comment: Welcome and thanks for your answer. Answers are required to be backed up by credible sources in this community, preferably journal papers, but credible web pages (hosted by universities *etc*) are OK too. Wikipedia is tolerated, but I tend to downvote answers based on wiki pages only. I'm bannering this one. Cheers


How to pray Salatul Duha?

Question: How and when do i pray Salatul Duha (Sunrise Prayer).
Answer: Salat ad-Doha is an optional prayer which has according madhhabs a level between mandub and sunnah muakkadah (based on ahadith such as this of abu Hurrairah and this on the authority of abu ad-Darda' and abu Dharr).
The time for this optional prayer is after sunrise and before noon (a possible evidence for the starting time is this hadith from Jami'a at-Tirmdihi and the timing is limited by this sahih hadith).
The most preferred time for it is after the half of the time between sunrise and noon.

The scholars defined this as being when one quarter of the day has passed, i.e., halfway between sunrise and Zuhr prayer.
  See al-Majmoo' by al-Nawawi, 4/36;  al-Mawsoo'ah al-Fiqhiyyah, 27/224 . (Source islamqa #22389)

About the amount of raka'a's there's a consensus on the minimum (two raka'a's, based on narration such as this in sahih Muslim) while the there's a dispute on the maximum amount.
The Maliki's, Shafi'is and Hanbalis say it is eight raka'a based on ahadith such as here and here in sahih Muslim if one performed more those would be considered as nafl (optional). However some Shafi'is said it was tweleve due to a hadith compiled by imam al-Bayhaqi. The hanafis said the maximum is sixteen raka'a. Othe scholars among them imam at-Tabari said there's no limitation.
As for how to pray it the majority of scholars say one may pray it in two by two sets (as described here in the narration compiled by ibn Majah)and it is also permissible to pray it as four by four sets. ...
Additional references in Arabic Article and this fatwa on islamweb #28916
Answer: Assalamu'Alaykum O Rahmatullah O Barokatuh!
The question should be what time to pray salatul Duha.
Us after sun rise for example in London is at 07:30 after that time you can start to pray 2 rajah or 4. You can pray by two rakah like the Farj prayer or by 4 rakah like Duhur Asr Isha.
All the Salah are the same there is no difference. So you pray in the same way you pray Fard payer.
Assalamu'Alaykum O Rahmatullah O Barokatuh!
Take care.

How to pray Salatul Duha?


Not able to get list of schema names when I pass publication ID and with ItemTypeCriteria schema by using Broker API

Question: int iPubId = Integer.parseInt(publicationId);
CriteriaFactory criteriaFactory = new CriteriaFactory();
PublicationCriteria pubCriteria = new PublicationCriteria(iPubId);
ItemTypeCriteria IsSchema = new ItemTypeCriteria(ItemTypes.SCHEMA);
Criteria allCriteria = criteriaFactory.And(pubCriteria,IsSchema);
Query myQuery = new Query();
myQuery.setCriteria(allCriteria);
SortParameter sortParameter = new SortParameter(SortParameter.ITEMS_TITLE,
                                                SortParameter.ASCENDING);
myQuery.addSorting(sortParameter);
String[] itemResults = myQuery.executeQuery();
System.out.println("RERERERESULTS:"+itemResults.length);

Comment: Hello and welcome the Tridion Stack Exchange. Are you setup to actually publish *schemas*? You can filter to get certain component presentations based on a given schema, but the schemas aren't available in Content Delivery afaik, unless you put them there.
Answer: I am guessing your issue is related to this:
https://stackoverflow.com/questions/14530742/schematitlecriteria-yield-no-results-in-sdl-tridion-broker-query
I found that the titles of the schema's names are not actually deployed to the broker until at least one DCP based on that Schema has been published.
Comment: Hmm, I don't read the question this way. It looks like the OP is trying to create a query to get back the list of schema names. The other scenario is about getting DCPs based on a specific schema. Is the full list of schema names possible with the CD API in a single query?
Answer: Try this way:-
Query myQuery = new Query();

Criteria myCriteria = null;
ItemTypeCriteria isSchema = new ItemTypeCriteria(8);
PublicationCriteria pubCriteria = new PublicationCriteria(251);
AndCriteria andCriteria = new AndCriteria(isSchema, pubCriteria);

myCriteria = andCriteria;

myQuery.setCriteria(myCriteria);

SortParameter sortParameter = new SortParameter(SortParameter.ITEMS_SCHEMA_ID,
                                                SortParameter.ASCENDING);

myQuery.addSorting(sortParameter);
//myQuery.setResultFilter(new LimitFilter(25));

String[] itemResults = myQuery.executeQuery();
System.out.println("RESULTS: " + itemResults.length);

Note that I haven't tested yet
Answer: You can, by default, publish pages and (dynamic) component presentations to content delivery along with their metadata (including template metadata now, I believe).
Schemas may be in the Broker database, but doing the following doesn't make sense (I'd expect components or pages):
ItemTypeCriteria IsSchema = new ItemTypeCriteria(ItemTypes.SCHEMA);

You can, however, get all CPs based on a specific schema:
SchemaTitleCriteria criteria = new SchemaTitleCriteria("article");

You could get the list of schemas in delivery by publishing out a configuration (xml) page or store it in a dcp. This might be a use case to use the Core Service in delivery, but I wouldn't recommend it.
You could also configure Tridion.ContentManager.config to actually render schemas but you'd need a custom resolver along with whatever content delivery code you need to get this information. But it'd be easier to use a template building block assembly.
Comment: Schema Names are  published along with DCPs, but not if the components are just embedded on a page
Comment: Makes sense. In my setup I can see at least two schemas in the schemas table but can't get them back via the API (without first getting the DCPs).
Comment: But I still doubt we can get the *list* of schemas in a single query. :-)


Wireless doesn't work in 12.10

Question: I have Ubuntu 12.10. I have cabled in my TP Link Wi-Fi USB adpter but it doesn't work. Can anyone tell me where can I find drivers for linux? My model is TL-WN722N at 150 Mb/s.
Answer: You need to investigate 'USB mode switch' settings to support your particular modem. Otherwise, it will look like a USB storage device to Ubuntu.

See answer in: USB mode switch - Some Background
Answer: What's the output of your ifconfig and iwconfig commands?
Have you tried the ndiswrapper approach? http://sourceforge.net/apps/mediawiki/ndiswrapper/index.php?title=TP-Link_TL-WN722N

Wireless doesn't work in 12.10


Are qubits preferred over qumode, and if so, why?

Question: Qubit and qumode are different forms of quantum computation. But most existing quantum computers/chips seems to be of discrete variables. I heard that a group chose qubit for a quantum optical frequency comb experiment relating to quantum computing because the environment noise of continuous variable is much higher. Is this a reason for preferring qubit to qumode at present (if people do prefer it)?
Answer: Both models have their potential advantages and disadvantages. The CV model doesn't require energy intensive cooling systems. CV will also work better for continuous-valued problems. Nevertheless, since the model uses photons it brings various challenges to the table as well. Since both models (especially CV)  aren't developed, your question may not be the right one to ask right now.
If you're interested, I know that Xanadu is developing the CV model. They have some papers on CV algorithms and QML out right now.
Comment: Thanks, actually I have been studying things about the CV quantum computation for several years (as a beginner). But recently I have heard some pessimistic views about CV quantum computing, especially those implemented on optical devices. That's why I asked the question ^_^||| Xanadu's work is very interesting. Thanks for your introduction.


What logs should I check after a break-in?

Question: I've asked this same question on superuser but I didn't have that much succes. I'd like to learn more about forensic analysis, and I'm doing the challenges from Project Honeynet. I need to check the logfiles and see the IP's that connected remote to a computer. I have a dd image of the harddrive, and the only service that was running was apache. Besides Apache's logs, what other logfiles should I look into, to see who connected to the computer? I'm only interested in remote connections. As for the Linux system, we can consider it generic, with a 2.4 kernel.
Comment: Related but side note-you can't trust anything on a system that is broken into. It should be logging everything to a remote system...
Answer: everything. auth, syslog, messages, .bash_history, last, utmp, wtmp, cron logs, /tmp. thats just a start really because an attacker with root privs can alter anything (and probably did), so you have to find a place that was forgotten.
Answer: I agree with neoice and Bart.
Also, maybe check if any file-alteration monitoring tool (or rootkit monitoring tool) was installed (examples include, but aren't limited to: samhain, tripwire, rthunter). samhain/tripwire could give you the list of modified files, and rootkit hunter could show you not only suspected rootkits, but also other problematic areas. Actually, you may even want to run your rootkit hunter in a chroot to that disk image...


If you have a rental car from outside Germany, can you enter the environmental zones?

Question: If you have a rental car from outside Germany, without a so called "Umwelt-plakette" or environmental sticker what do I have to do to enter the environmental zones? Can I get a waiver if I show that I have a rental agreement?
Comment: Everybody can enter the environmental zones… the difficult part is avoiding the fine ;-)
Answer: As you probably know, cars registered abroad are not generally exempt from the environmental sticker requirement. The official websites from many cities are very explicit about that and the law includes provisions to determine in which category cars registered abroad fall. It would therefore be somewhat surprising if rental cars were exempted (after all, promoting tourism and the practical difficulties involved were not enough to justify an exemption…).
The law does however include a provision for the federal government to exempt some vehicles. Those include things like cars used by someone with a disability, official vehicles from the police, etc. but not rental cars (either local or foreign).
Furthermore, the cities and provinces can add some rules. There are many such rules and some of them are especially relevant for tourists (e.g. vehicles with a yellow sticker registered abroad can sometimes be used in places where German-registered vehicles need a green one) but I am not aware of any blanket exemption for rentals. You can find detailed information on these exceptions on each city's website or on the ADAC website.
Incidentally, the police can fine you even if you are not in the car. Since it's increasingly common for fines to be sent abroad within the EU, it would be likely to end up at your rental shop, which would presumably promptly charge you for it. Even if you would actually qualify for some exception, it would seem quite difficult to get the money back in these conditions.
Answer: No you cannot get a waiver. Entering the environmental zones without a sticker will get you fined. You can get a sticker for 5 EUR at a TÜV or DEKRA branch by showing the vehicle's registration papers.
Comment: @Gagravarr: if you don't have them with you, you'd actually be breaking another German law.
Comment: @andra: No, I'm saying that foreign rental agencies which allow their cars to be taken into Germany will provide such papers.
Comment: @andra Photocopies are regularly not sufficient, the originals are required. One may be lucky and have a lenient cop, but one may be fined for not carrying the originals. That is the registration certificate as defined in 1999/37/EG...
Comment: Would you have the vehicle's registration papers though, if you rented the car in a different country?
Comment: @michaelBorgwardt are you saying all foreign rental cars in germany are illegal?
Comment: @MichaelBorgwardt It usually is a copy of those papers
Answer: while the answers by Michael Borgwardt and Relaxed are both correct, you shouldn't worry about this too much - getting fined just for not having this sticker is not very common. Usually you'd be fined if you get stopped e.g. for driving too fast or parking violations and the police notices the missing sticker. also the police in Germany might be OK if you just tell them you didn't know
YMMV, the whole thing depends a bit on the city you want to visit - in Berlin for example this is handled very relaxed.
Comment: Difficult to know for sure but [it seems to be getting more common](http://www.tagesspiegel.de/berlin/immer-mehr-bussgeldbescheide-umweltzone-ueberfordert-autofahrer-/6246406.html) (for comparison, I think there is something like 3 million speed tickets issued per year in Germany, so fines for driving in a restricted zone without a sticker are indeed much less common).
Comment: Pretending that you didn't know may prove difficult, though, as you drive past a [rather explicit sign](http://www.erfurt.de/mam/ef/wirtschaft/erwicon/2014/fittosize_85_708_0_eb0e0b2e1748c53d9bb88457b96c300f_2012-05-08_umweltzone_bila.jpg) (it even shows what the sticker looks like!) upon entering a restricted area. Maybe colour blindness might work as an excuse ...


what does it mean by cold cache and warm cache concept?

Question: I read a paper and it used terms "cold cache" and "warm cache". What does it mean by cold cache and warm cache concept? I visit this but I need something more.
Comment: What would you regard as useful? How do you intend to use the information? I only ask because, you know: https://www.google.com/search?q=wikipedia+cold+cache
Comment: I wanna use this concept in my paper so i need more details about them .
Comment: It's just using temperature as a metaphor for understanding how useful a particular cache is since "usefulness" exists on a continuum. Warmer caches have high hit rates whereas cold caches are filled with data you're probably not going to ask for again any time soon and so they're just taking up space.
Comment: @JoelDavis - If caches did not need to handle errors then the above would be true, and the *only* method of replacing cached data that would have ever needed developing would be LFU, but because data is prone to error for a variety of reasons, handling a cold cache is a little more complicated than just replacing least-used data.
Answer: Well, in short: a warm cache is useful whereas a cold cache is not. In fact, a cold cache can be dangerous to use.
You see, the whole point of a cache is to keep oft-accessed data accessible. For instance a DNS cache will store locally the results of the name-resolutions that you've requested recently, and, when those same resolutions are requested again their results are already available and served immediately without querying a larger, likely off-site name database. In other words your computer doesn't have to ask your internet service provider's domain name server for the ip address to google.com because your computer already knows it - your DNS cache is warm.
But if you never request google's ip then it won't be in your cache. A cold cache is either too stale to be useful - as in the data it contains is likely too old to be accurate  - or it is entirely empty, and empty's plenty cold.
But often empty is better than old - though this is highly dependent, of course, on the data that is being cached. Empty's easy to handle because it just needs filling - that's a no-brainer - but old caches require error-correction. This is the primary logistical problem of developing and maintaining cache systems - how can you know the data you've cached is up to date and what is done if it isn't?
I won't be answering either of those questions - they're both implementation dependent and probably far and away beyond my capability, anyway - but it should be understood that all caching systems come with some inherent risk of inaccuracy. It goes with the territory. The risk may not be great - often it is only a risk of a few extra nanoseconds in processing time. The cache system will check requested data against whatever failsafe has been implemented by the cache designer and, if it's found wanting, then the cache system will, for instance, query the ISP's DNS for google's ip and all is well.
The warmer the cache, though, the less there is risked.
The warm cache's benefits of keeping dear data near outweigh the risks of the cold cache's drawbacks or... probably you shouldn't be caching.
Comment: As the famous quote goes, "There are two hard problems in computer science: Naming things, *Cache invalidation*, and off-by-one errors." Knowing that your cached values are old is exactly what cache invalidation means :)
Comment: On your comment about cache inaccuracy, that's not necessarily true. If the system/application has exclusive access to the data source, then cache entries can be updated or evicted as appropriate. It's only if you're dealing with concurrently accessed sources (e.g DNS, NFS or CIFS) that you run into this problem (even if only one has write access, such as with DNS).
Comment: "else why are you caching at all" Same reason you would have for caching anything else: protection against high latency. For example the filesystem cache is just so the OS doesn't have to go out to disk for common requests. The cache is still in a coherent state, though, since modifications to local filesystems would have to go through the kernel anyways. The ECC part isn't really relevant since that kind of corruption isn't due to caching being caching, it's due to a hardware error that would hit all systems equally no matter how they were designed.
Comment: The disk is a cache of RAM?
Comment: I think you have the relationship reversed. The recently accessed contents of disk are cached in RAM so memory is a cache for disk (or is at least used as part of the caching system). Disk access is the slow operation that storing stuff in memory is designed to get around.
Answer: In general, a cold cache is one that is not well populated (yet). So if your cache is cold, information must be retrieved using the, presumably, slower method. This is typically the case shortly after an application starts up or the types of queries change significantly.
Conversely a warm cache is well populated with information that you have recently or frequently retrieved.
With respect to ext filesystems and directory structures, there is some information about how caching generally works in the Virtual File System (VFS) in Linux here: http://www.tldp.org/LDP/tlk/fs/filesystem.html
Comment: @FaheemMitha It's true - LFU is definitely a very common acronym you'll encounter in this department. If your cache is reasonably certain to contain only recent information and it is full, then you must have some other means of determining which information is replaced as you read in new data. LFU is probably the way you'll go.
Comment: "recently or frequently"? Recently, yes. but frequently?
Comment: http://en.wikipedia.org/wiki/Least-Frequently_Used
Comment: @cpugeniusmv Thanks for the link. That could reasonably be included in your answer.


Guidelines for using Production Data in test environments

Question: Any one have any good recommendations/guideline policies about using production data within testing environments (sensitive vs non-sensitive)?
Answer: I'd suggest taking a look at this question and the answers first. There's some good information in this question as well.
The amount of data cleaning you need to do will depend on your application and regulatory environment. As a general guideline, any financial data must be scrubbed even if encrypted (if financial data isn't encrypted on your production system that's a whole other issue). Any personally identifiable data should be scrubbed even if encrypted. Personally identifiable data for children may be subject to stricter rules than personally identifiable data for adults.
Things to watch for:

Data scrubbing isn't just deleting anything sensitive. You'll need to replace it with something that meets validation and other data integrity rules.
The algorithm used to transform data should be one-way only.
Once transformed, your data should still be subject to the same business rules and still meet business rule standards. This gets particularly tricky when there is cross-validation being performed (e.g. does the state match the postal code).
Transformed data used to identify records needs to stay internally consistent. For instance, if a common lookup in your application is by social security number, then User X's social security number must be transformed to the same value in every part of the database it's found. (Yes, I know it's not good practice to use something like SSN as a key, but that doesn't mean you won't find tons of places that do this, my workplace among them).


How do I make my gas furnace throw out warmer air?

Question: I just bought a new house. It has a 2007 gas furnace. The make is a 2007 heil furnace .
I would like to know how to adjust the furnace to make it throw warmer air out of the ducts.
Answer: You can't.  Furnaces are either one stage where they output a single temperature, or two stage where they output two different temperatures depending on the temperature difference they make up.  Your thermostat controls this.
The air coming out of your furnace is far hotter then your thermostat setting, but your thermostat shuts off the furnace when the ambient air temperature reaches its setting.
Your only real option you can control is how long you run the furnace for.
Answer: As @Steven has stated the temperature is fixed based on the size of the burner, which is dictated by the design of the furnace. There are things you can do to increase the efficiency some you can do and some require a burner technician. Make sure the filter is clean, make sure the registers (outputs and returns) aren't blocked by furniture, check for leaks in the exposed duct work and seal with metal or duct tape not to be confused with the silver packing tape. Insulate any exposed ductwork that is uninsulated. If you haven't done it this year have the furnace inspected and cleaned and adjusted, also ask  if the ductwork needs cleaning.
Comment: Not duct tape, only metal tape.. Duct tape is not for ducts.


How does system testing differ from System Integration Testing (SIT)?

Question: I was asked this question during an interview. My thoughts are SIT is performed on a complete systems and System Testing can be done on a single module as well.
Comment: In an interview situation it might be good to be careful about these kinds of concepts. They are sometimes connected to a specific usage in one standard (or methodology) and could have a different flavor or meaning in a different standard. I would prefix the answer with something like: in my experience, or in the method we used ...
Answer: Systems testing is often performed against the whole platform, and treats the environment as a black box. system integration testing however, acts upon a subset of the whole system, and may mock other platforms, interact with databases, network sockets etc to evoke appropriate responses from the parts being validated.
The objectives of system testing is to validate the public exposed interfaces of the platform, by behaving as an end user, with no privileged access to internal systems. Integration verification attempts to verify that seperate systems operate well together before they're used in the whole system.
Comment: @Toby, in my dictionary there are **integration tests**, **system tests**, and **system integration tests**, so the integration goes bottom-up. All of course depends on where you put boundaries between your and other systems. So I would say integration tests verify integration of **internal** interfaces inside of your system, in system tests you mock **external** interfaces, and in system integration tests you play with real external interfaces. Whatever you call it, the point is to verify both internal interface integration and external interface integration.
Comment: Perfect! Clearly i was wrong about System Testing. Thanks a ton.
Comment: No problem, feel free to accept the answer if you think I answered your question. :-)
Comment: I would call testing parts of the system, possibly with mocks, just "integration testing" and system integration testing would be different thing. Just goes to show that it's good to make sure others are using the terms in the same way. :-)
Comment: @dzieciou lets say we have a system C which is combination of A and B (A + B = C). Now i can check perform Integration tests for A, Integration tests for B. After this i need to perform System tests on C which is the result(whole system). Where exactly will SIT come in here?
Comment: @Dan If you build all those parts yourself and they are all complete programs, you do integration tests for subparts of A and B, system tests for A and B and system integration tests for combination of A and B. If A and B are not complete systems themselves, you don't have any system integration testing to be done.
Comment: @Dan, see my answer. Wouldn't fit a single comment ;-)
Answer: In your comment you asked

Lets say we have a system C which is combination of A and B (A + B = C). Now i can check perform Integration tests for A, Integration tests for B. After this i need to perform System tests on C which is the result(whole system). Where exactly will SIT come in here?

In testing C, but I believe you won't learn much from short answers.
The long answer is the following. You have a system of systems here. You may perform tests at the same level (single system, system of systems), but at each level you may want to focus on different risks (integration problems, whole functionality).
Example
So let's say you're developing a system A (e.g., online shop) that interacts with external (i.e., not under your control) system B (e.g., PayPal).

Testing whole system A you may verify whether it does what is was requested to, e.g., you are able to select and order a product (system A tests). You may also focus on integration problems here, e.g., because system A integrates backend with frontend (UI). For instance, how frontend behaves when backend is down or backend response is delayed?

Testing A integrated with B you may focus on different problems. You may verify whether after ordering a product money were transferred from your PayPal account to shop account (functionality). This is system C tests. You may also check what will happen when your online shop does not pass (optional) description in payment request to PayPal (more about integration). I would call this system C integration tests.

Conclusion
You may always consult ISTQB glossary and ISTQB Syllabus if you need clear definitions. Practice is, however, more interesting. You combine multiple dimensions of testing: level (subsystem, system, system of the systems) and risk focus (functionality, integration problems, etc.). And often the boundary between what you test is not so clear. For instance, when you test your online shop functionality, at the same time you are also making sure that backend and frontend has been integrated correctly. The book "Lessons Learned in Software Testing" explains nicely about this combination of testing dimensions in "Lesson 48: Testing combines techniques that focus on testers, coverage, potential problems, activities, and evaluation".
To learn more about what risks integration tests focus on, see another answer.
Comment: Very well explained, and thanks for the ISTQB link :)
Answer: In my vocabulary system testing would be testing one complete product  ( http://en.wikipedia.org/wiki/System_testing ) and system integration testing would be testing combination of products ( http://en.wikipedia.org/wiki/System_integration_testing ). As always, it's good to make sure others are using terms in the same way and in an interview point out that you know about the ambiguity.
Answer: System Testing is performed on completed software or application. Integration Testing happens in 2 places - Before System Testing and After System Testing. Integration Testing can be split as Integration and Testing which means you are integrating the unit or components and testing the handshakes between these modules. Once the integration testing is done for all the modules, you perform the System testing as we now have the completed system. After System Testing and before User Acceptance Testing, we do the System Integration Testing. This term can be split into two - System Integration and Testing. Now imagine, your system has to integrate with another system to provide a solution to the end user. Now, you need to make sure your System is compatible and is able to exchange information with the other system. To ensure this, we perform system integration testing.
Example: You buy a COTS (Commercial Off the Shelf) product from the market. You will perform SIT to make sure, it talks to your existing system.
Hope this clarifies.
Answer: A good explanation can also be found in this slide:
System Test: As soon as an integrated set of modules has been combined to form your application, system testing can then be performed. System testing verifies the system-level reliability and functionality of the product by testing your application in the integrated system.
Note: QA team performs System testing/ done by independent test group
Integration Test: Integration testing is used to test the reliability and functionality of groups of units (modules) that have been combined together into larger segments. The most efficient method of integration is to slowly and progressively combine the separate modules into small segments rather than merging all the units into large component.
Note: Test engineers performs Integration testing in development phase


In Buddhism Can Devas do Something For Us?

Question: My mother is a christian woman but has strong traditional roots in voodooism and ancestral worship.My question is,Is it possible for human beings to invoke a deva/gods/territorial spirits(nagas etc) to do our bidding? In a Buddhist context Can a Deva help a human being? Is there such a story in the suttas.Why would a Deva help a human being? According to my mother a particular deva helps us because he was our family/relative/ancestor.Is this compatible with Buddhist Beliefs?
Answer: In Buddhist scriptures, devas are described as powerful beings who often interact with humans. So assuming devas are real, they can surely hinder or help humans in a material way. What no being can ever do is force or hinder another's spiritual path. There we are truly alone. Even Mara can only tempt beings to stray from the skillful path but can never succeed as long as we can see through its illusions.
Answer: Like a friend or even an animal (some cases animals have help people) can help us there are instances where beings in other planes can help us. This includes Devas. Again like a friend or animal they may be limited in their ability including due to the plane they are in.
Answer: Yes they can.
If one does good, particular "higher" beings (including Buddhas) can more easily help that being (they are attracted to the good karma).
If one does evil, asuras can more easily haunt that being (they are attracted to the evil karma).
There are many other properties to them that are completely irrelevant to the Buddhist project (see Noble Truths) and the importance of meditation and attainment within our extremely fortuitous but also extremely brief life-time...
But to answer your last question... yes it is compatible but also remember that Hindus also believe in this stuff. The difference with Buddhism from all (inferior) traditions is  there exists Buddhahood for the sake of all beings and the Three Trainings and this has little to do with over-concern for worldly matters (e.g. Mythbusters and other obsessions with paranormal phenomena). The Buddha himself said this and so did Confucius (who had Enlightenment).
To satisfy your curiousity though, devas are mentioned throughout the scriptures and the Buddha mentions his experiences with them in vivid detail.
The following is a taste of the first half of "The Mind Experiment" with excerpts from respective suttas:

The "devas" (collective name for heavenly beings) are not above men or
  outside the world, not transcendent but immanent, worldly beings. They
  all have distinct features and occupy certain positions in a vast
  hierarchy of levels, each heaven providing specific qualities of life
  and environment, body and consciousness. There is a Lord God in most
  realms but no one is in charge of the whole; there is no super lord,
  no unique and supreme ruler of the universe, no divine creator of all
  and everything.
Some Gods believe themselves to be eternal and almighty because of the
  exceptional qualities of their existence – such as an extremely long
  lifespan, unwavering happiness, extensive presence, power, and
  knowledge – which makes it difficult for them to "see things as they
  are" (impermanent, suffering, non-self, empty; Chapter 1). They enjoy
  such bliss and brilliance that it is difficult for them to realize
  that all beings are, in essence, equal; that their godly state is just
  a matter of natural and temporal retribution, the result of their own
  excellent karma, and that they too are subject to the universal law of
  causality, to suffering and frustration when their karma runs out.
  They experience decay, death and rebirth (in a lower plane). By
  themselves they do not discern ultimate truth, but when they did upon
  hearing the Buddha's teaching, "they beat their breasts and wept" (AN
  ii 33).
Gods are finite because they exist. They are delimited and conditioned
  by their own thusness, by the very attributes and properties
  (skandhas) that make them divine. They are "imprisoned in their
  person" (SN iii 85). Although none of them are responsible for the
  world or for other beings, they do have more-than-human powers. Their
  destiny highly exceeds our human one, because they have been much
  better than we have been; it is their excellent karma that took them
  there. Therefore we should emulate them for the moral and spiritual
  qualities that earned them such splendid existence. As religions know,
  they can appear on earth and interact with humans, they can protect us
  and intervene on our behalf; they are affected by our prayers, which
  they can answer insofar as [1] their power extends to us, and [2] we
  have the spiritual capacity and karmic affinity to receive their help.
  But there is not much they can do to alter man's destiny or their own.
Gods and heavens are part of and evolve within the whole of existence,
  or they would not exist. They are no exception to the general rule but
  subject to the universal process of origination-cessation just like
  the rest of us, ruled by cause and effect. They evolve according to
  the natural law and order of the universe (Dharma). Heavens and hells,
  gods and angels, spirits and demons are not a matter of mythology but
  of cosmology.
There is much more to reality than what our senses and brain register.
  From the human level, the pure worlds above are perceived when the
  mind ascends in pure concentration (dhyana-samadhi). "sursum corda" –
  lift up your hearts – is to be taken literally. To "contemplate God in
  Heaven" has been the main purpose of all religious exercise: to
  cultivate a supernatural awareness through prayer, moral excellence
  and mental purity, single-minded faith and contemplation. That means
  essentially to develop dhyana-concentration, to shut out the world of
  the senses, to silence the distraction of thought, to rise above this
  earthly-bodily dimension and "unite with Heaven."
At times when spiritual cultivation was more developed, gods and
  heavens were a natural part of life, as can be seen in the traditions
  of Greco-Roman culture, Judeo-Christianity, Islam, Hinduism, Daoism,
  and other religions. All of these offer observations that match one or
  more aspects of the heavenly reality as it has been elucidated in
  Buddhism. The Buddha's omniscience covered the whole of reality, and
  his revelations about gods and heavens have been, and can always be,
  corroborated by people with adequate samadhi power. There is nothing
  exclusively Buddhist about it; any spiritual adept can discern the
  superstructure of the universe.
The Buddha once described a heavenly voyage undertaken by one of his
  followers, to whom "the thought occurred: "I wonder where the four
  great elements—earth, water, fire, and air—cease without remainder"
  (in other words, "what is beyond the physical universe"). And that
  brother attained to such a state of mental concentration that the way
  to the deva-realms appeared before him." After having gone through the
  consecutive realms of the lower heavens and having put his question to
  the gods there (who referred him each time to a higher instance), "he
  became so absorbed in concentration that the way to the Brahma-world
  appeared before his mind thus pacified. He went to the gods of
  Brahma's Assembly . . .  then the Great Brahma himself appeared . . .
  and finally, as swiftly as a strong man flexes his arm, he vanished
  from the Brahma world and appeared in my presence" (DN i 215-222).
  The Buddha himself proceeded likewise. Once asked about the
  whereabouts of a group of his followers who had recently died, "he sat
  down, thinking over, considering and concentrating his whole mind on
  the question of them, making a resolve: I will find their future,
  their fate after this life, whatever it is. And then he perceived the
  destiny of each one of them. In the evening, after he emerged from
  meditation, looking bright and shining . . .  [the Buddha said:] 'Then
  an invisible spirit made himself known . . . and appeared himself
  before me, a splendid presence'." It was the spirit of a former king
  who explained his rebirth among gods as a king of non-humans, who now
  wanted to engage on the path of enlightenment and was asking the
  Buddha for advice. (DN ii 204)
On several occasions the Buddha described in detail the rebirths of
  disciples who were recently deceased, also mentioning their actual
  status on the path of spiritual realization. He advised his students
  to see this for themselves and explained a manner of self-inspection,
  like looking in a mirror, to discern clearly one's future and make
  sure that: "I have destroyed hell, animal-rebirth, ghost-realm, evil
  fates, and sorry states. I am a Stream-enterer (first stage of the
  path), incapable of falling back into states of woe, certain of
  attaining Nirvana." (DN ii 92-94) When he spoke about rebirth, he
  frequently warned against being reborn in the "descents" and "states
  of woe," among animals, afflicted spirits and miserable ghosts, or
  worst of all, in one of the hells.
Comment: That would be shirk , so how would you reconcile that with Islam?


Is there a name for the following gambling fallacy?

Question: I'm writing a paper on the game of blackjack and I'm trying to make a point about how a common player's attitude is a logical/statistical fallacy in the following situation:
When any common person steps up to a blackjack table, they realize that the odds are slightly in the dealer's favor (they're correct), but they also realize (correctly) that there's enough variability from the mean on any given hand for them to make some profit. Now they still won't bet a massive amount on any given hand, fearing that that variability could swing in the negative direction rather than the positive, but they might settle upon a smaller, "safer" bet that they'll make consistently. Their assumption (and this is where the fallacy comes in) is that they'll be able to make a large profit over time by betting a small amount on each hand and taking advantage of the large variability on each given hand.
In reality, as they play more and more hands, that standard deviation which overshadowed the mean cash gained for a single hand begins to dwindle in comparison to the mean. This is because the standard deviation increases proportionally to the square root of the number of trials whereas the mean increases proportionally to the number of trials. So, in the long run, the player will no longer be able to take advantage of that high volatility and will be in fact doomed (with a certainty of essentially 1) to lose money.
I realize this is a rather technical scenario (maybe more statistics than philosophy), but might there be any formal name for this sort of fallacy? (Or maybe a snappy-sounding name I could construct?)
Answer: It's just the fallacy of composition. The person is reasoning: It is possible for me to make money on a single hand, therefore it is possible for me to make money on a (sufficiently large) set of hands. The inference is incorrect, for the reason you mention above.


How do I make my room or even an apartment warmer/cozier?

Question: I'm currently living in an apartment paid by the company I work for, It's a 3 bedroom apartment, and each room has a bed for whoever is staying/living at the moment, the apartment tends to get really cold even when the sun is already rising everyday, I blame the coldness of the apartment to the lack of furniture in this apartment. I've managed to turn my room into a partial home by getting some basic furniture, 2 coffee tables, a dresser, a couch yet the apartment keeps getting so cold during nighttime, I know buying a heater is the easiest way to go, but I really want to fly low expense wise, since I'm only gonna be here til June. What are some easy and cheap alternatives to heat up my room(maybe, if possible, even the whole apartment) and keep it warm during the day and specially during the night? PS I've covered my window with a thick blanket to avoid some of the cold getting inside but it's still not enough.
Comment: Is there a thermostat?
Comment: No @James , it doesn't
Comment: Maybe it would help if we knew where you are located geographically.
Comment: Mexico city, so it'll still get chilly during the night even mid June. @James
Comment: Get a large (metal)tank full of water. Keep it near the window allow it to heat all the day by sunlight. Water will retain heat as it takes long time for water to either heat or cool
Comment: By the water tank hack you can at least spend night
Comment: @Fennekin If you have an answer, please post it below. Thanks.
Comment: You will spend and waste more water using that method than purchasing a 10 dollar heater at your local wallyworld or budget store...
Comment: What temperatures are we talking about anyway? Inside and outside, day and night?
Comment: Temperatures are trivial, since the feeling of being "cold" varies since everyone has different tolerance for different temperatures @hkBst
Answer: I assume the heat is escaping through the windows - which means they are probably single glazed.
Even if they are double glazed, you will get a big improvement by putting plastic film over the windows to increase their insulation level. It's very cheap and easy to fit. Here is an example on Amazon UK:
Answer: Let the sun in during the day, without opening windows. You need as much sun light as possible. Clean the windows, remove the curtains and blinds. The sun will warm the floor and walls and they will stay warmer during the evening.
You also have to reduce loss of heat. During the night close your windows and doors tightly. If there are gaps - use isolation band for doors and windows. Put thick curtains on the windows after sunset.
You can try to paint the outside wall in black, but it wont be cheaper than buying a simple electric heater and you will have the opposite problem during the summer.
Comment: Cost isn't that big of a deal, the only reason I'm not that convinced of buying a heater it's mainly cause I'm gonna move out in like 6 months. And I won't be able to take everything with me. For example my furniture, I won't be able to take it with me in the plane, so they're probably staying behind
Comment: Than you might wanna have look at simple space heaters: http://www.amazon.com/Space-Heaters-Home-Appliances/b?ie=UTF8&node=510182
Comment: Buy a cheap space heater, use it until you move it out, and leave it for the next person who will use the apartment and who will have the same problem.
Answer: The furnace in my house went out in the dead of winter last year (I live in Cincinnati, Oh - so it gets a little cold in the winter) I still haven't bothered getting it fixed even though this winter. All I did was bought a few little space heaters online (the best ones are the radiator style electric oil heaters they crank out some serious heat), some plastic sheeting that has adhesive strips to put over the windows and vents, some semi thin foam strips with adhesive to put on the inner sides of the door jams, and keep any doors closed to unused rooms putting blankets under the door to cut down on the draft. This all may be slightly excessive for you, but maybe some of the ideas could improve the temp for you.
Answer: In houses I lived in, Windows were often the weak spot of the heat insulation where heat is lost at night. Make sure the window and frame tighten correctly and you don't get wind through. You can buy rolls of rubber in case it isn't shutting tight e.g. on ebay. Alternatively and additionally, close the roller shutter do reduce wind blowing past the window and carrying heat away or pressing through remaining gaps (haven't wrapped my mind about how much of infrared radiation gets kept in the flat by closing the roller shutter).
On the inside of the window, close the curtains at night to reduce air circulation past the window (you may notice weak cold wind next to your window). (Again, if you don't have roller shutters, the curtains should lock infrared raddiation in, no idea how relevant this actually is)
Hack yourself. Ginger makes you warmer. I didn't investigate if it only makes you feel warmer or actually raises the body temperature (there are many people on the internet claiming it would increase your metabolism). My guts feeling is it feels 1-2°C warmer when you had a ginger tea on top of having had a warm drink. In Nepal in mountain huts they freshly rasp 1-2 teaspoons of ginger into the tea, I usually slice 1cm to 1 finger thick ginger into ~1mm thick slices (as thin as possible while still easy to cut), and put them in a cup of boiling water. If you don't like the taste, maybe add a bag of any kind of tea/infusion. In the office I don't want to worry about storing fresh ginger and have a caster of dried ground ginger which I put in a cup of infusion. It's a bit annoying to have the powder in the infusion when drinking though.
NB: I've been told that various kinds of drinks/fruits have the opposite of the desired effect (making you feel colder), so combining the ginger with those in the infusion might be a bad idea. Blamed were anything with caffein and citrus fruit, I didn't test that.
Answer: Keep your oven door open after cooking dinner, if you dont have a oven, you can also create your own candle heater using terra cotta pots.
Link here if interested... how to make your own candle heater
Comment: We don't have an oven(weird I know, and I don't really want to buy a lot of appliances, furniture since I'm not going to be here for long) but I'll take a look at the candle heater
Comment: How did this work out for you? It is a method that works 100%. Let us know if you decided to go down that route :)
Answer: Put on some more clothes when it gets cold, and get a thicker (or another) blanket for your bed.
Comment: This is an obvious answer, but you gotta remember that while at home we want to be comfortable as well, having 3 layers of clothes on won't feel very comfortable, and I have no issues of cold while in bed. It's the temperature of the rest of the house on a daily basis what bothers me, not the temperature of my bed when I sleep.
Comment: Sometimes the right answer does not require more than one line...


What is the difference between a go-around and a missed approach?

Question: What is the difference between a go-around and a missed approach? What are the steps involved in each of the procedures?
Answer: Approach, missed approach, departure & holding
Approach, missed approach, departure and holding are published instrument procedures. They are characterised by waypoints, alitudes, headings, climb-, and descend profiles.
An approach procedure tells you how to get from cruise to short final, from a holding to short final, or from cruise into a holding.
A missed approach procedure tells you how to get from climb out into a holding or to another point from where you can commence a new approach.
A departure procedure tells you how to get from climb out to cruise flight.
Takeoff, landing, go around & touch and go
Landing is the process of getting an aircraft from short final to a full stop on the runway.
Takeoff is the process of getting an aircraft from a full stop to climb out.
A go around takes an aircraft from short final to climb out directly, not touching the runway.
A touch and go takes the aircraft from short final to climb out, touching the runway in the process.
Relationships
The procedures listed above can be combined arbitrarily. Even though a missed approach is often flown after a go around, they are not synonymous. Missed approaches can also be (and are) flown after a touch and go, or, for training purposes, after a takeoff. Also, a missed approach is not the only thing you can follow after a go around: Sometimes, you want to perform a departure and continue toward your alternate destination.
Answer: A go around is terminology generally used during VFR flight. If a pilot is approaching the runway to land and decides that conditions are not conducive to a safe landing, he can opt to "go around". This can be for a wide variety of reasons including the pilot or aircraft being unprepared for the landing, the descent to landing being performed poorly, or even animals/FOD on the runway.
In a go around, the pilot will first apply power, then "clean up" by retracting flaps/gear as necessary to reduce drag (down to 20 degrees in a C172). Once a positive rate of climb has been established, the pilot will remove the remaining flaps and radio that he is going around. Generally the pilot will re-enter the traffic pattern and attempt to land again.
A missed approach is terminology used exclusively with instrument approaches. Instrument approaches always have a missed approach procedure in case the pilot is unable to complete the approach. This most often happens when cloud cover and visibility are poorer than allowed by the approach. If a pilot descends to a certain altitude and is unable to see the landing environment or at least the airport lights, he will "clean up" similarly to the go around procedure discussed above, tell ATC that they have "gone missed" and then follow the steps outlined on the instrument approach plate.  These steps generally involve the aircraft climbing to a safe altitude and entering a hold.  At this point the pilot can choose what their next course of action is.
Missed approaches can also be used if the pilot decides that he isn't well prepared for the approach, and the missed approach procedure must be initiated if the pilot doesn't stick to the approach closely enough.
Comment: You are wrong. Go-around is used in IFR aswell. I have heard ATC instruct aircraft multiple times: "BAW123 Go-Around I say again Go-Around, aknowledge". It is AFTER this instruction that they tell them to follow Standard Missed Approach PROC
Comment: I used and bolded the phrase "generally used during VFR flight" on purpose. While I too have heard it used during a landing done after an instrument approach, I think you would agree that while possible, go arounds are much more common during VFR flight.
Comment: Admittedly I've only been instrument rated for a year, but I have never been ordered to go around while flying IFR.  I have heard it happen once. Go arounds seem downright common for GA VFR flight. This seems super minor though, so I'll agree to disagree with you. I am US-based and you appear to be Canadian from your source, maybe there's some difference we aren't aware of.
Comment: I am trying to tell you that the Go-Around instruction is used on both IFR and VFR if needed. As far as I know VFR aircraft rarely request a Go-Around, but they frequently request a Touch and Go. Go-Around is used by ATC/Pilots when one side or another decides that it is unsafe to land, and is requested-issued when the aircraft is on final approach. Generally speaking, go arounds are used on IFR as much as VFR.
Comment: ^CAP 413, Chapter 4 Paragraph 65
Comment: "Go Around"  is used for both VFR and IFR. An IFR pilot will fly the "Missed Approach Procedure" after the "Go Aound" is initiated.
Answer: "Go Around" is the ATC instruction used in any circumstances, IFR or VFR, where it is necessary to execute a Missed Approach. There is no instruction such as "make Missed Approach", the instruction is "Go Around".


Can someone help me identify this Brazilian spider?

Question: Does anyone know anything about the identification of this spider? Sorry, but it's the only image I have. It was shot at 2004, January 25th (summer), at 11:27 AM, in Cerrado biome at Minas Gerais state, Brazil. It was walking over a Paepalanthus inflorescence (Eriocaulaceae), probably waiting to prey on its pollinators. A small section of web can be seen raised to the left (where it apparently comes from another inflorescence), touches one of the small flowers, and then it's apparently still connected to the spider, in a pattern that reminds me of Salticidae, though I'm not sure. I think its size is around 1 cm. I doubt a specific identification will be possible, but family, superfamily, subfamily, anything will be fine.
Answer: Interesting!  See those long spines on the legs?  Only two groups of spiders (that come to mind, anyway) have that sort of arrangement:
Lynx Spiders (Family Oxyopidae) and Pirate Spiders (Family Mimetidae).
Lynx Spiders are wandering hunters, and the ones I'm familiar with tend to have a body shape more like the familiar Grass Spiders (longish, tear-drop shaped abdomen and hunters cephalothorax - roughly rectangular, and often very blocky at the face.
For instance:
https://bugguide.net/node/view/1965

https://bugguide.net/node/view/1489229/bgimage
So, your spider looks to be a South American Lynx Spider, which unfortunately I'm not at all knowledgeable about.
I'm going to discount Pirate Spiders as a possibility, even with the association there with a bit of web (Pirate Spiders invade other species' webs and kill the occupants), because they're much more 'orb-weaver'-like in their general body shape.  This one is so Lynx Spider-like that I am pretty confident that it is one of those.


Can I Ghost Quarter to fetch basic land, while tapping my Gemstone Mine for mana using its last counter?

Question: My Gemstone Mine has 1 counter left. I tap it, remove 1 counter to produce B. Is the sacrifice effect a triggered ability -- meaning I have time to Ghost Quarter it and fetch a basic land?
Answer: You cannot do this.
Gemstone Mine's ability is a mana ability, which means that it does not use the stack. So it cannot be responded to; by the time you could do anything after activating it, Gemstone Mine would already be in the graveyard, and could not be targeted by Ghost Quarter.

605.1. Some activated abilities and some triggered abilities are mana abilities, which are subject to special rules. Only abilities that meet either of the following two sets of criteria are mana abilities, regardless of what other effects they may generate or what timing restrictions (such as "Activate this ability only any time you could cast an instant") they may have.

605.1a An activated ability is a mana ability if it meets all of the following criteria: it doesn't have a target, it could add mana to a player's mana pool when it resolves, and it's not a loyalty ability. (See rule 606, "Loyalty Abilities.")

605.3b An activated mana ability doesn't go on the stack, so it can't be targeted, countered, or otherwise responded to. Rather, it resolves immediately after it is activated.

Note that also you cannot accomplish this by switching the order. If you activate Ghost Quarter's ability first, and then respond to it by using Gemstone Mine, then when Ghost Quarter tries to resolve, it will not resolve because all of its targets are now illegal.

608. Resolving Spells and Abilities

608.2b If the spell or ability specifies targets, it checks whether the targets are still legal. A target that's no longer in the zone it was in when it was targeted is illegal. Other changes to the game state may cause a target to no longer be legal; for example, its characteristics may have changed or an effect may have changed the text of the spell. If the source of an ability has left the zone it was in, its last known information is used during this process. If all its targets, for every instance of the word "target," are now illegal, the spell or ability doesn't resolve. It's removed from the stack and, if it's a spell, put into its owner's graveyard.

If Gemstone Mine's ability were a normal activated ability, instead of a mana ability, (if it didn't produce mana, or if it targeted something), then you would be able to do this, because you could activate Gemstone Mine's ability, then respond to it with Ghost Quarter while the ability was still on the stack.
Answer: No.  Gemstone Mine's ability is a mana ability (Rule 605.1), which means it resolves immediately and doesn't use the stack (Rule 405.6).  Because of this, there is never an opportunity to "respond" to the portion of the ability that sacrifices Gemstone Mine.  So you're forced to either produce the mana (and immediately sacrifice Gemstone Mine) or target your land with your Ghost Quarter.
Comprehensive rules references: (emphasis mine)

405.6. Some things that happen during the game don't use the stack.
405.6c Mana abilities resolve immediately. If a mana ability both produces mana and has another effect, the mana is produced and the other effect happens immediately. If a player had priority before a mana ability was activated, that player gets priority after it resolves. (See rule 605,
"Mana Abilities.")

Definition of mana ability:

605.1a An activated ability is a mana ability if it meets all of the following criteria: it doesn't have a
target, it could add mana to a player's mana pool when it resolves, and it's not a loyalty ability.
Answer: No. The http://gatherer.wizards.com page, which Glorfindel has edited to include in your question, answers this: "Sacrificing this card when the last counter is removed is part of the effect of tapping it for mana."  If there were a carriage return between "Add one mana of any color." and "If there are no mining counters on Gemstone Mine, sacrifice it.", that would be a different matter; there would then be two separate abilities: an activated mana ability and a triggered ability. As it is, it's one block of text that is all one activated mana ability, and since it's a mana ability, it doesn't use the stack.
Comment: The text "If there are no mining counters on Gemstone Mine, sacrifice it" is not a valid ability on its own. If the "If" were instead "When", it would in fact be a triggered ability, but in that case it would be a triggered ability whether or not it is part of the activated ability.


How does running speed correlate to burnt calories?

Question: I'm thinking of something like, say, a line diagram. The horizontal axis would be "running speed" and the vertical axis something like "calories per minute". Has this matter ever been scientifically researched?
Comment: https://europepmc.org/abstract/med/870783 calories should be proportional to oxygen rate. it's a line. the gradient varies between individuals.
Comment: Well.... I know guys who can run 6 minute miles and have a conversation like they're walking. If I tried to run a 6 minute mile, I'd be gasping for air in about 30 seconds. The difference? Heart rate. Calorie burn is mostly dependent on heart rate and not speed. What's fast for some isn't fast for all. So, running a 6 minute mile for me would burn far more calories than a 6 minute mile for someone else. Heart rate increases to supply demand of oxygen from muscles that need them. The higher the demand the more calories
Comment: @Frank - Heart rate is not really a reliable gauge of calorie burn. There is an estimation because there is a somewhat linear relationship in steady state exercise between hr and vo2 uptake. But take the same person in two different workouts. One workout is at 90bpm running 10 minute miles, the next day they have extra coffee or fatigue, and the same 10 minute miles are now at 100 bpm. They are not burning an extra 10% calories.
Answer: It would look like this:

It's basically a straight line. Don't take the variations from the straight line too seriously. There are so many other factors involved (wind, distance, running form, etc.) that it doesn't make sense to try to measure it too precisely. The graph above is for a 30 year-old male with 70 kg and 1.75 m, calculated with the corrected MET values taken from the Compendium of Physical Activities. You can make your own graph with your personal parameters with this spreadsheet.
It is well-known that you burn approximately the same calories per km independently of speed. A fortunate numerical coincidence allows us to simplify the formula and simply take the speed in km/h to get how many calories you burn per kg per hour. For example: a 100 kg person running at 12 km/h burns about 1200 kcal per hour and a 50 kg person running at 20 km/h burns about 1000 kcal/h.
Comment: the chart you provided doesn't effectively prove your final point, as it seems to show that you burn more calories the faster you run, when in your final paragraph you say you don't. the vertical axis in the chart should be calories per kilometer, not calories per minute. obviously you will burn more calories if you run fast for a minute versus running slow for a minute, since you've just covered more ground (and your body has done more work).
Comment: @user3163495 The OP asked for calories per minute, which is what the chart shows. And it's not meant to prove my final point. The spreadsheet I linked to shows the graph you're interested in. It's basically an horizontal line. If you want to learn how everything was calculated, read https://sites.google.com/site/compendiumofphysicalactivities/corrected-mets or https://en.wikipedia.org/wiki/Metabolic_equivalent_of_task
Answer: Short answer: the line on such a diagram would just be a straight horizontal line. Running faster does not significantly increase calories burned.
Long answer: A "calorie" in the context of food and exercise is actually short for "kilocalorie", which is a unit of energy (or "work", as some people say).
Just like 1 mile is equal to 5,280 feet, 1 kilocalorie is equal to 4,184 Joules, which is the same amount of energy/work required to raise the temperature of 1 kilogram of water by 1° Celsius.
Let's say you dragged a 100lbs boulder 20 feet across the ground. No matter how fast you dragged that boulder, it will always be the same amount of work done: 100lbs moved 20 feet.
So, based on how much you weigh, the amount of calories you burn running a mile will roughly be the same no matter how fast you run. I know it sounds counter-intuitive, since running fast is harder than running slow, but that's science.
You might burn a few more calories in the wind since wind resistance increases the faster you go, but it's not very significant unless you are absolutely sprinting.
That is the reason the calculator on this site will always give you the same number of calories burned, no matter how fast a time you put for the "How long you ran" box:
https://www.runnersworld.com/training/a20801301/calories-burned-running-calculator/
Caveat: calories burned while running will always be the same, but there might be some increased after-burn of calories if you ran the mile super fast as opposed to normal speed, since your body has to work harder to catch its breath, cool off, etc.
Comment: As far as I read it, you argue that distance matters, but speed does not!
This also match an very old rule-of-thump: `energy(in kcal) ~ your weight(in kg)*distance (in kg)`.


How can we flag question that belongs on another site in the Stack Exchange network?

Question: I don't understand how to flag the question so it can migrate in other S.E. sites. It seems that when I flag it and I choose  "This question belongs on another site in the Stack Exchange network" can be only be migrated to Chemistry meta. I think physics, biology, mathematics should be included.
Comment: Relevant *why* I marked this as declined: [Why are there no migrations paths to Physics.SE, Math.SE, etc.?](https://chemistry.meta.stackexchange.com/q/4202/4945) [Guidelines for closing as off-topic, belong on a different SE](https://chemistry.meta.stackexchange.com/q/3963/4945)
Comment: I found [this](http://meta.unix.stackexchange.com/questions/882/how-to-migrate-questions-from-stackoverflow). I found that interesting and helpful.
Comment: @Martin yes but in fact unix have 5 sites we have only 1 site (meta), but we could have 5 I hope that someone notice this feature request and activate at least physics and biology...
Answer: We don't currently set up migration paths until after a site leaves the beta phase. The notion is that while in beta, a site's on- and off-topic lists will likely be in flux a bit. We don't want to set up migration paths and have content start flying around that was decided is off-topic, then maybe the community decides it was on-topic after all, etc. Additionally, migrations should be fairly rare, anyway; you should not only be sure that a particular question is off-topic for your site: you should be equally sure that it is on-topic for the destination site.
It doesn't hurt to think about which sites might someday be useful to have as migration paths from Chemistry.SE, but they won't be set up quite yet.


List field: translated values are not translated

Question: In my Drupal 8 project I have some list fields. For example maybe a field "project type" with the following key|values, coming from the original language German:
1 -> öffentliches Projekt
2 -> privates Projekt

Which I translated in the field's settings:
1 -> public project
2 -> private project

The field is NOT set to be translatable because the value should not be changed in a translation: the project type is in all languages the same! But now when I go to the node edit page, when I view the node or when I add this field as exposed filter to views I always see the German values of the field no matter what is set as the current language of the page. When I change the field to be translatable the value of the list field can be changed in English translation -> so it can come that a project is "public" in German and "private" in English what is not the desired result.
How do I get the translated values of a list field to be used in form element and node view when the list field itself should not be translatable?
Comment: You always enter the English strings/labels only in the field config, then display the form at least once in German, and after that go to interface translation and translate them to German. I think.
Answer: Ok, it seems that it was just a weird cache thing. I cleared the cache several times after changing these translations. Now the translated values of the select list appear without setting the field to be translatable.


Substitute for a tablet stylus

Question: I do a lot of sketching and drawing on my iPad. I usually use a stylus, but I recently lost mine. I can draw with my fingers, but I would prefer to use a stylus because it's just easier and I can do more stuff with one. I'm getting a new one soon (probably), but I need something to replace it for a week or two. What is a good substitute for a tablet stylus?
Comment: South Korean [sausage stylus](http://www.engadget.com/2010/02/11/south-korean-iphone-users-turn-to-sausages-as-a-cold-weather-me/). Really.
Answer: A carrot is a great 'on-the-fly' method, and doubles up as a healthy snack for after.
cheap, and readily available in most homes.
Comment: I don't really understand the down votes as most people have carrots... It's a very unusual solution too
Comment: If you down-vote me, please tell me why.
Answer: Aluminum foil works similarly to a stylus. I've successfully created a stylus by wrapping several (~7) layers of aluminum foil over the eraser end of a pencil. Note that the contact points will not be as smooth as with a good stylus (e.g., lines drawn may be dashed) and if the foil rips it may scratch the screen, so be cautious.
Comment: This is indeed the most easy and cheap way to replace a stylus. Just make sure, that you wrap a big enough piece of aluminum foil over your object (you can use anything you like, for example an empty ballpoint pen or chopsticks) so that your **fingers are in contact with the foil** when holding your self-made stylus. This is essential, because it's the only way the electrostatic energy can travel from your fingertips to the tablet.
Answer: Using Aluminum foil has already been mentioned by Mooseman. Since there are different ways of crafting your own stylus, I'd like to expand on this a bit.
The following method found on CNET uses aluminum foil as well but also includes a Q-tip to accomplish a screen gentle meeting place:
Here's what you'll need:

A cotton swab (aka "Q-tip")
Aluminum foil
Scissors
Tape
A pen

Steps:

Remove the ink from the pen.
Cut the cotton swab at a sharp angle and insert it into the mouth of the pen. Secure with tape.
Wrap the foil around the neck of the pen, a couple of centimeters above the tip of the cotton swab. Wrap tightly, and secure with tape at the top.
Moisten the cotton swab with a drop of water. (No, this will not harm your tablet's or phone's screen.)

This is what the process should look like:

Another method found on lifehacker uses conductive foam instead of aluminum foil. Here's a video in case you don't like reading instructions.
What you'll need:

A small piece of conductive foam (the kind that microchips and other small electronic parts come embedded in)
Scissors
A not insulated wire or a wire stripper to remove insulation more than twice the length of your pen
Tape
A pen

Steps:

Remove the ink from the pen.
Disassemble the rear of the pen so that you get a tube. If you can't easily achieve this, you may want to use a different pen or try to break the rear off.
Cut a small stripe off of the conductive foam so it's a little bit wider than the tip of the pen.
Wrap the wire around the foam multiple times at about one-third of the stripe.
Stuff the piece of conductive foam into the tip of the pen, making sure that some of the foam sticks out of the pen and the wire sticks out of the rear of the pen.
Wrap the excess wire around the pen in a spiral course (in direction of the tip).
Fix it in position with tape so that you're touching the wire with your skin while holding the pen normally.
Trim the sticking out foam so that it has a more round shape.

This is how it might look like:
Comment: Great answer! Safe for screens and cheap. Only prob, a bit clumsy, but that is the way with a lot of hand made styluses.
Answer: Any object with the following properties can act as a stylus:

The tip must be able to conduct electricity (like metal or a wet sponge)
It must conduct electricity to your hand (a pair of pliers with insulated handles doesn't work because the current cannot flow into your hand)
The tip must be roughly the size of a finger tip (in my experiment, it had to be wider than 5mm). Most displays filter out small points of contact to reduce unintentional activation.

The result of my 5 minutes experiment looks like this:

That leaves one last problem: how to avoid scratches on your display?

Tape a small piece of damp sponge to the tip of your DIY stylus
Wrap and tape a piece of normal office paper around the tip and slightly dampen it with water.
Cut a little piece of foil from either a bag of potato chips / crisps (the kind that looks silver on the inside) or an anti-static bag that electronic components are usually packed in. Tape that around the tip of your stylus.
If you happen to have conductive tape, simply tape a small piece onto the tip.

Substitute for a tablet stylus


What is the meaning and origin of the surname Nesselrothees?

Question: I am having trouble finding anything out about the surname Nesselrothees. My great grandmother was registered under the surname in 1840 England. Her father was Alexander Dorow Nesselrothees. He was apparently from Frankfurt.
Comment: Welcome to Genealogy.SE. You can find an introduction to our site in our [tour]. Could you please name your sources, e.g. for the origin of Alexander Dorow Nesselrothees?
Answer: If the family origin is indeed Germany, the name Nesselrothees reminds me of the German nobel family of Nesselrode. There is an extensive Wikipedia article (in German) on this family: Nesselrode (Adelsgeschlecht). Please provide more information on your great-great-grandfather, e.g. by linking sources. If there is a sourced link to Germany, I can maybe help with further research ideas to connect the name to the family mentioned above. The family name Nesselrode comes from Nessel ("nettel") and -rodung, an suffix meaning "clearing". The place linked to the family origins is Nesselrath, also referred to as Nesselrode in medieval times.
Answer:
The original spelling may have been "Nesselrath". A search for "Nesselr*" in the Historic German addressbooks includes a number of Nesselrath entries, and some additional variants: Nesselrat, Nesselroda, Nesselrode, Nesselrodt, Nesselroth
Since "Nessel" is also a surname, consider that "Nesselrothees" may have been a hyphenated name. Although "Rothees" does not appear in the previously referenced database, Rothes does: thus "Nessel-Rothes".

A final consideration: there are 2 German cities named Frankfurt, and a number of smaller placenames that include Frankfurt in the name.
Answer: It has taken me over 20 years to find my great grandmothers birth the reason being I have been looking for her under the surname Wolff which is the name she and her family were using on the 1851 English Census. I have since found 6 of her siblings registered under the name Nesselrothees. I have her birth certificate and have ordered some of the others.
I have 6 births and one death under the name Nesselrothees and maybe 4 births and 2 deaths under the name Wolff. Her fathers name on the 1851 census was Alexander Heinrich Wolff born Frankfurt on the Mein, occupation Professor of Piano Forte. He died in 1855. He was 20 years older than his wife and in saying that I can't find a marriage for them.
Comment: Welcome to G&FH.SE!  I also would like to encourage you to take the [tour].  Stack Exchange is not a forum -- it is a question-and-answer site.  Your post will be deleted because it is not an answer to the question you posted above -- if you want to ask a question about finding this marriage record, please ask a new question and copy this information into that question, using the guidelines in [How do I ask a good question?](http://genealogy.stackexchange.com/help/how-to-ask).
Comment: I agree that the information that you have provided here will be very useful as a new question about finding the marriage certificate (which may inadvertently turn up new leads). However, it does not qualify as an answer to the original question you asked here about the origin and meaning of the surname.
Comment: My 3x Great Grandfather is Alexander Heinrich Wolff, but have no information on his family. Were you ever able to find out the link between Wolff and Nesselrothees?