Launch HN: AmpUp (YC W19) – A reservable electric car charging network - <AUTHOR> Hi HN,
This is Tom from ampUp (https://ampup.io/). We're building a reservable electric car charging network out of shared private and home chargers.
As a Nissan Leaf driver without a home charger, charging has been almost a daily headache for me. For many commutes and trips I have to ask myself, should I drive my Leaf, use Uber, take public transit, walk really far, or just not go? This is due to the walk-in-only model of the public charger, which results in unpredictable availability. Worse, public charging is growing at a slower rate than EV adoption, and the range estimators on EVs are no better than a 10-day weather forecast.
I used the Plugshare app and it helped some, particularly the couch surfing style of charging where I arrange a 2 hour slot with some home charger hosts. When it worked well, it took out the unpredictability and therefore anxiety. However, it doesn't always work well. Many times hosts won't respond to text/calls to make the booking, and a couple times I forgot to bring cash/check to pay for the electricity as the host indicated.
My first attempt at this problem was building a webapp that worked as an addon to Plugshare where hosts can create a calendar for their charger, and set an hourly price where drivers can pay via credit card. Once that's set up, the host would paste the unique url to their charger's calendar in the description section of their Plugshare listing. Long story short, this added as much inconvenience as benefit, and drivers still ended up calling the host.
Given enough interests from hosts and based on experiences of a few drivers including myself, I decided to make a second attempt and just build a better app that focuses on the hosting and reservation flows.
After about 2 months of hustling and grinding, we released ampUp (https://ampup.io/), where users can host multiple chargers at flexible schedules and adjustable prices. Since the hosts set up sharing calendar for their chargers, the other users can make reservations with instantaneous confirmation. We use Stripe to enable peer to peer payment with credit card rather than cash/check. We know EV owners are willing to pay for charging and it's important for hosts to be able to make a meaningful amount if we want to scale this to match our vision where one day there will always be a reservable charger near where the user is or will be. From our analysis, with a competitive (to public charger) pricing of $3/hr, hosts can expect to make $190-$270/month in profit with just 3 rented hours per day.
For ampUp, our business model is to charge a flat 1 dollar to the driver per reservation. If we use the $3/hr example from earlier, a 3 hour session will cost a total of $10 to add about 60 miles from a residential level 2 charger. This "fuel" cost is on par with the most fuel-efficient gas car which is the Mitsubishi Mirage. These numbers are based on Bay Area electricity and gas costs.
ampUp already has thousands of hosts, but many of them are listings we collected from all over the internet. The difference in the user experience with those hosts is that we have to confirm the reservation with them, as opposed to our own. This is a temporary limitation in the "do things that don't scale" spirit. Our goal is to instantly confirm
reservations like Airbnb.
We sincerely invite the HN community's feedback on our idea and on the app and everything else in this space. You can reach me directly at email@example.com or for firstname.lastname@example.com. You can download the app at the top of https://ampup.io/. We hope ampUp will help more people to drive their electric vehicles as effortlessly as driving a gas car! <comment><USER2> > From our analysis, with a competitive (to public charger) pricing of $3/hr, > hosts can expect to make $190-$270/month in profit with just 3 rented hours > per day.

$3/hr * 3 hours/day * 30 days = $270. However, this doesn't subtract the cost of electricity to the provider.

My local utility (San Diego Gas & Electric) has a (rather high) standard-rate of $0.51578/kwh in summer (beyond >400% of baseline, which I assume I would hit if I was powering EVs 3 hours every day) [1]. Nissan Leaf's Level 2 charging is 6.6kw [2], so my cost calculation for this service would be:

$0.51578 kwh * 6.6 kw * 3 hours/day * 30 days = $306

So my napkin math says I would _lose_ money ($36/month) providing this service. Am I missing something or would I have to charge more than $3/hour to stay out of the red?

[1] [https://www.sdge.com/sites/default/files/regulatory/3-1-19%2...](https://www.sdge.com/sites/default/files/regulatory/3-1-19%20Schedule%20DR%20Total%20Rates%20Table_0.pdf)

[2] [https://pluginamerica.org/understanding-electric-vehicle- cha...](https://pluginamerica.org/understanding-electric-vehicle-charging/)

<comment><AUTHOR> Yes, the calculation is based on $0.19/kWh charged by PG&E, with tiered rate, that cost does go up. So hosts will need to adjust the hourly prices depending on local cost and actual traffic. The $270 is from hosts with solar panels that have credits stored up. One user living in Santa Clara has 15000 kWhs saved up from almost a decade use of solar.

<comment><USER2> Thanks, that's a helpful example. This does sound like a great way for residential solar users to offload excess production, particularly if they can't tie it back to the grid directly (e.g., SDG&E's Net Energy Metering program [1]), or if the service rates can be higher than the grid-tie rates.

I guess that underscores that the napkin math gets pretty complicated and local use-cases can vary greatly. I'd be very interested in user-focused calculators that could help in guiding these napkin-math decisions the right hourly price to set locally, and/or whether the combo of residential-utility rates and local average public-charging prices makes it worth providing the service at all.

[1] [https://www.sdge.com/residential/savings-center/solar- power-...](https://www.sdge.com/residential/savings-center/solar-power- renewable-energy/net-energy-metering)

<comment><AUTHOR> Yes, we have a ticket in the back-log to offer a feature that recommend pricing for the hosts. Taking into account public charging rates, utility rates, and traffic. The smart switch also has the purpose to distinguish charging vs just parking. So in some areas, we want to offer a separate rate for parking in the future.

</comment></comment></comment></comment><comment><USER3> This is really cool Tom! A couple of questions:

\- I don't have an electric car charger, but my understanding is that the charger is usually located inside a garage, meaning that the host would have to let the driver into the garage/house. If that's the case, what kind of liability insurance would AmpUp provide?

\- Does AmpUp provide pricing recommendations for hosts, or provide information on what other hosts on the platform are charging?

\- Is there a internal ratings system for hosts/drivers like Lyft/Uber? Otherwise if a host provides a date/time for charging and doesn't show up and it becomes a major logic path, you would have to provide calls/text support anyways.

\- Are you concerned about the possible gamification of prices and hosts on the platform, like that of Airbnb's, that may unduly affect pricing or quality of service for customers that would box you into a corner, and are there any game plans developed for tackling such behavior?

Best of luck, and hope to see greater EV adoption because of AmpUp!

<comment><AUTHOR> Ratings and reviews are coming. Right now hosts on ampUp are nearly all hand picked. A lot of home chargers in the Bay Area are installed outdoor, and for the ones installed in door the current hosts are all very nice people. I've been to a bunch of them myself. For term of use and liability, we currently roughly follow the same used by Airbnb, but we definitely plan to update. I'm not too concerned about hosts asking for high prices, because public charging will always be an option, so public charging prices will act as a reference.

</comment></comment><comment> z-cam Congrats on launching! Great job getting >1,000 hosts in a concentrated area-- this is where others have fallen short with this idea.

Do you have plans to integrate with public & semi-private CPOs? (charge point operators)

We are a startup CPO. I'm thinking about some of our multi-res customers who installed stations in visitor parking. They have asked us to list their stations publicly so they can recoup their initial costs. Your platform might be a good fit for this.

Let me know if this is interesting!

<comment><AUTHOR> Let's talk! That sounds very interesting. We firmly believe in the reservation based model. Taxis use to be hailed, but now we reserve them. firstname.lastname@example.com

<comment> z-cam Yes, removing the uncertainty of if there is a plug available is a big plus

Talk soon!

</comment></comment></comment><comment><USER4> In TX I got quote for $500-$800 for installing charging panel anywhere I want. I am confused why wouldn't somebody who has a house, and can afford EV car with $7500 credit, not make ONE TIME investment of $1k (US average pricing) to _permanently_ setup house for EV charging?.

Also there is a high chance of pissing neighbors off if you have constant stream of new cars coming into the street, I know me and my neighbors would be, as we have kids playing outside.

<comment><USER5> Not to mention a lot of utilities will give you rebates for charging equipment. PG&E is now up to an $800 rebate if you switch to their EV plan... that will buy the charger or the install.

It's knowing about all these rates and rebates that's tricky. Dealers should be able to provide you with all this info, but well, that's a whole other story...

<comment><AUTHOR> Yes, I'm still planning to install a home charger and share it.

</comment></comment></comment><comment><USER6> "As a Nissan Leaf driver without a home charger" isn't that the main problem and not the current charging network?

<comment><USER7> I am also a Nissan Leaf driver. Charging at home is possibly the best reason to have one. Unlike a gas car, I can leave home for every trip with a full "tank".

<comment><AUTHOR> Fully juiced. haha. Well, I think many people are jealous of you, me included. I actually live in a single family house, but my electric panel is all the way in the backyard. I don't have a sub-panel in the garage. The quotes I got are all around $2000 total to install home charging for me. I wanted to install one and share with people, but so far haven't been able to pull the trigger.

<comment><USER8> Do you currently just use level 1 charging, or not at all?

Most EVs charge at about 3mph from L1, and if you're on-plug for 10 hours overnight, hey, that's longer than a lot of people commute in a day. Might be able to keep your SoC pretty high with that alone.

Of course L1 is too slow to be useful for sharing, but for a resident it often works out quite well.

<comment><AUTHOR> Yes, that is my fall back option. I still keep the charging cable that came with the Leaf in the trunk, just in case!

So far, I haven't needed to go to the fall back option. I charge at a l2 host place near my work, and once a week I go to a fast charger near some restaurant.

</comment></comment></comment></comment></comment><comment><USER9> First off, congrats on the launch and for tackling an underappreciated problem with EVs.

I'm excited about the concept, because it has the elements of something great. But I'm skeptical about the "sharing economy" approach of renting out time on home chargers. Like others have mentioned, the real problem is affordable, available chargers at the user's residence, rather than trying to make more chargers available in residential neighborhoods.

But the other problem that EV users have, especially users that aren't simple there-and-back commuters, is that they need _predictable_ and _dependable_ charging while away from home.

I own an EV myself, and I can't tell you how many times I've made a trip somewhere during the day, expecting to have a charger available, only to find that they're all taken when I arrive. This is somewhat alleviated by networked chargers, where you can see whether they're available beforehand, but there's been many occasions where the charger is snagged by someone else while I'm driving there. Because of this I'm extremely cautious about driving too far in a given day, and in fact, end up using a regular gasoline car if I know I have to drive beyond the range of my EV, since it's too hard to tell if and when I'll be able to charge along the way.

So where your concept comes in is the ability to reserve chargers. That means I can actually plan my day, plan a road trip, etc. And ideally the chargers will be in the same places I actually want to go - along freeways, in shopping centers, downtown, etc (i.e. not far off in residential areas).

I could definitely see this as a service that could plug into existing networks (e.g. EVGo, Blink, Chargepoint, etc), although getting them all to play nice together is difficult. But I would heartily applaud someone who could organize and simplify EV charging away from home and make it dependable and predictable. Good luck!

<comment><AUTHOR> Hi Jason,

I can tell this problem has affected you and you have thought about it deeply. Really appreciate your feedbacks. Overall I agree with you completely. The biggest assumption regarding this startup/project is that the p2p charging market can be build up to a substantial size beyond just one-off emergencies or long road trip cases. This is something some folks doubt and something I'm betting my blood, sweat and tears in. What makes me confident is my own experience. I was FORCED to try the couch surfing type of charging with Plugshare first that I was super skeptical of myself, and LUCKILY my first experience worked really well. I also noticed with just 2 simple features the experience can be mostly consistently good. There are more than 10,000 hosts on Plugshare, and if the experience can be consistently good, it could turn into THE largest charging network in the world. We are not there, but I want to get there.

</comment></comment><comment><USER10> Very interesting idea with great potential. I'm sure you will iron out the problems because the demand is certainly there. May I ask what your tech stack is for the app and also are you going to develop a web app and what will be the tech stack for that? Or is a web app seen as unimportant?

</comment><comment><USER11> So this costs the driver $1 per 6 miles? If gas is $3/gallon and my car gets 24 mpg, then I'm paying $1 per 6 miles. This is not on par with the Mirage's 36/43mpg.

Your service effectively makes electric cars equally or more expensive to drive than gas cars. Could work but seems to remove a solid benefit of EVs.

<comment><AUTHOR> You have a point on this one. However, it's not my service that's causing this. The price suggested was based on public charging rate, and the money will go to the hosts. There's no way to guarantee profit for the hosts always given electricity rates will change and gas prices will likely drop. The miles per kWh also changes depending on how you drive and the weather. Typical users will have a combination of home, workplace, public, and peer to peer charging. The total should still make EVs cheaper to drive. If all chargings are done via ampUp, yes the cost maybe as high or even higher than driving gas car. It's not likely, and peer to peer charging does add the reservation/predictability benefit to it.

</comment></comment><comment><USER12> Awesome project!

Few notes about the website:

Check the meta tags. "title" says "Template" and "description" says "Sample". I tried to share this with my friends and url preview said Template / Sample.

Currently your website title is "Home" it probably should be your apps name.

Good luck.

<comment><AUTHOR> Thank you!

</comment></comment><comment><USER13> > From our analysis, with a competitive (to public charger) pricing of $3/hr

My 2012 Leaf takes 3 hours to fully charge on a L2 charger, and that gets me 35-40 miles range. $9 for 35-40 miles. My Camaro gets 20 miles to the gallon, it's significantly cheaper to put gas in the 320HP Camaro than pay this kind of rate for charging.

<comment><AUTHOR> A 6.6 kW L2 charger should put about 20 miles per hour of charging, so for 3 hours that's 60 miles. I do believe the 2012 Leaf gets maybe 40 in total, since battery degrade and older Leafs actually tell you how much your battery has degraded.

With that exact example of $3/hr, yes it's more expensive to use p2p charging than driving your Camaro. There are hosts that offer cheaper or free charging. The $3/hr is an example based on public charging rate in the Bay Area. Another case is if the host happen to be in a highly visited location and charge $10/hr for charging and parking.

EVs are still overall a bit more expensive than gas cars. That's why there are still subsidies. In the bigger picture, it's still paramount we switch to a cleaner and more sustainable energy source, and electrifying transportation is an inevitable step. I'm confident the technology will mature and will mature fast.

</comment></comment><comment><AUTHOR> We are still working on a long list of exciting features collected from user feedbacks and my personal experiences. Please stay tuned for those by following our Twitter: [https://twitter.com/ampup_io](https://twitter.com/ampup_io)

</comment><comment><USER14> I am happy you all are launching and wish you well. Increasingly seems the companies launching on HN are in search of a problem. Renting a charger because you don't have one at home seems like a backwards way to solve the problem! But, I am only one person and not the market

<comment><AUTHOR> There are definitely more than one way to solve a problem, and ampUp is just one of the many efforts out there trying to alleviate the range anxiety issue. The way you phrased seem to suggest everyone should install home charging, which is definitely not possible when more people adopt EVs. I started having a problem myself, then trying to use existing solution to solve my problem first, and finally offering something I think works better.

</comment></comment><comment><USER15> The problem still is the charging time. EV occupied the space longer than a gas car does refill. Until we reached the technology where the batteries can be charged in seconds, 'drive EV as effortlessly as driving a gas car' is a bit of overstatement i think.

<comment><USER8> For the majority of EV owners who do have home chargers, the "time you spend involved in charging" is about 10 seconds to plug in when you park at night, and 10 seconds to unplug and stow the cord the following morning. That's less time than you spend at the gas pump.

This also applies to folks who can charge at work. Charge speed does not matter if charging happens while you're inside doing something else for several hours.

</comment></comment><comment><USER16> Do hosts have to be home in person or are you guys partnering with smart garage door opener companies? I can't see letting people use my garage at night since space is a premium and I need to charge my own car.

<comment><AUTHOR> At this point if the charger is in an access restricted place, the host will need to somehow allow access. In California, there are many that have the charger installed outdoor and use the garage as another room or a gym. In the Bay Area, for instance, 36% of people who share their charger have it installed outdoor. For chargers installed outdoor, it's fully automated. Working with remote controlled garage opener and some security camera partners are definitely in our plans. We are also looking into the option of extending the charging cable, so it can be left outside.

<comment><USER8> Many chargers have wifi or bluetooth connectivity. Seems to me that there's an obvious integration here. Visitor's phone and charger authenticate each other, charging starts.

OpenEVSE could be a perfect platform for prototyping this. Our hackerspace has one on the wall right now, and we're adding another because so many members drive EVs now.

<comment><AUTHOR> Thank you! Let me know if you are open to try an integrated pilot with us.

</comment></comment></comment></comment><comment><USER17> Can't see how this will be a sustainable business, at all. The whole goal of the network is to eliminate the waiting problems. Which will be solved in 5 years.

<comment><AUTHOR> EV growth is much higher than charging infrastructure growth. The current network of public chargers are predominantly level 2 chargers. There are many things that limit public charging installations like architectural changes and grid upgrade involved that need approvals from different entities. Some apartment management refuse installations because the architectural changes would violate rights of some tenants. I have heard a year's time was taken from the moment HOA approved EVSE installation to the actual EVSE being installed. The most optimistic projection for EV adoption world wide by 2025 is 14%, and I strongly doubt charging infra will be sufficient or have caught up by then. This problem will get worse before it gets better. If we change the time frame to 10 years, many many things could happen and I hope ampUp can continue to adopt.

</comment></comment><comment><USER18> Awesome project, guys! Congratulations on the launch. Can't wait to see where this electrification takes us, and stoked YC is supporting EV startups. More!

<comment><AUTHOR> Thank you! We love feedbacks on the app to keep making it better. Email me directly at email@example.com

</comment></comment><comment><USER19> Genius! Applauding for the concept and clean, easy to understand design.

<comment><AUTHOR> Thank you for the encouragements! There are still a ton of work to be done to get the user experience to what we envision. Please keep the feedbacks coming!

</comment></comment><comment><USER20> Great Idea! I hope you have much success!</comment>


Modern C [pdf] - <AUTHOR> http://icube-icps.unistra.fr/img_auth.php/d/db/ModernC.pdf <comment><USER2> I might have to make a _What has changed in C since 1980_ page for old programmers. I've tried to stay current, but I learned something from this book already:

        size_t strlen(char const string[static 1]);
        int main(int argc, char* argv[argc+1]);

This allegedly helps prevent null pointers from being passed in, and presumably tells the analyzers and optimizers some things they should know.

It's worth a look at C11 as well, some of what you might have used gcc or clang attributes for has climbed into the language, such as _Noreturn, _Alignas, _Alignof and their friend aligned_alloc().

Addendum: Well, you can pass in pointers that go to fewer elements, but you can't pass in an actual naked null.

<comment><USER3> I didn't know about use of static keyword in array parameter declaration, but I dare to say that a lot of senior C programmers are unaware of this C99 feature.

It's nice to be able to specify function's expectations on that level, yet it looks that only clang (tested with 3.5.0) takes use of it, while gcc (tested with 4.9.1) seems oblivious to it. Be it NULL or shorter string literal than expected, gcc with -Wall -Wextra -pedantic -std=c99 spits nothing. Both mistakes are detected by clang.

Sadly even clang doesn't warn us when fun(int len, char str[static len+1]) is called like fun(5, "test").

But I'm not sure that I agree with the rule 22.214.171.124 Don't use NULL. In any sane C environment NULL is defined as follows (unless __cplusplus is already defined, because then it's defined as 0 or 0L)

        #define NULL ((void*)0)

and IMHO there is nothing wrong with that.

Distinguishing kind of 0 we're dealing with (even if it's not strongly guarded by compiler) is often important for readability and eases maintenance of the code (0 vs '\0' vs NULL). While comparing pointer with NULL (writing p == NULL or p != NULL instead of simply !p or p) may seem superfluous (yet I have nothing against programmers doing so), calling function with pointer parameters providing 0 argument instead of NULL seems less clear to me.

> if you really want to emphasize that the value is a pointer use the magic > token sequence (void *)0 directly.

I don't buy it.

<comment><USER4> One of musl libc guys wrote quite convincing article about NULL: [http://ewontfix.com/11/](http://ewontfix.com/11/)

There was also discussion on musl mailing list (I don't know is this best link to it): [http://www.openwall.com/lists/musl/2013/01/09/1](http://www.openwall.com/lists/musl/2013/01/09/1)

<comment><USER3> The topic was modern C and in modern C environment NULL is defined as

        (void *)0

There is no point in writing longer form and it's still clearer and safer than 0 alone.

C++ is another story with its

        void* hate

built-in. In this land you rather write

        (type*)0

or

        (type*)NULL

(or

        static_cast<type*>(0)

for extra purists), but as you're denoting pointer type already in this notation, there is not much gain in using NULL instead of 0 (well, beside grepability).

In many cases you can be done with 0 alone in C++, that's true, and in such cases NULL at least poses some intention, but if you're not careful enough, you may end up putting NULL alone (without pointer-to-type cast) in some variadic function and things start to blow up all of a sudden (that is if your NULL integer width isn't the same as pointer width). That's why having a habit of writing

        (type*)0

is a good thing in this land.

Regarding musl check also:

[http://git.musl- libc.org/cgit/musl/commit/include/stddef.h?i...](http://git.musl- libc.org/cgit/musl/commit/include/stddef.h?id=c8a9c221)

In short, musl's stddef.h has following lines:

        #ifdef __cplusplus
        #define NULL 0L
        #else
        #define NULL ((void*)0)
        #endif

NULL defined as 0L for C++ is nice workaround, but it works only for LP64 platforms.

In the same vein for Windows C++ x64 environment you need NULL to be 0LL, as it is LLP64 platform.

</comment></comment></comment></comment><comment><USER5> Please have a native English speaker edit this book before distributing it. It'd be a shame to have such substantial work dismissed due to awkward use of language.

<comment><USER6> I've just emailed the author offering to proof/edit. I used to do copy editing in a past life.

Update: He wrote back and agreed.

<comment><USER7> I love the internet when this happens. Thank you!

</comment></comment></comment><comment><USER8> Couple of things:

\- Pages 156 to 164 are missing (I tried to skip straight to the "Ambition" section but couldn't find it).

\- The first sentence, "It has been a long time since the programming language C is around" sounds wrong to a native English speaker. Say "The C programming language has been around for a long time" or "It has been a long time since the C programming language appeared". "Since" in English generally refers to things that happened in perfect tenses (as opposed to e.g. "depuis" in French that has an imperfect tone).

Hope these are helpful. Book sounds great.

<comment><USER9> Only the first 3 sections have been written, so the other stuff is coming later.

</comment></comment><comment><USER10> This looks awesome, I haven't had the need to become more proficient at C since having learned (the basics of ) it as my first language, but this gives me some motivation to learn more about it.

I also really like that the book can be read by people of varying levels of experience, with sections devoted to different groups.

</comment><comment><USER11> I really like C99. I've been trying to write C like that and the only problem is that there are some users who _really_ like their MSVC from 1998 that doesn't support half of that book.

<comment><USER12> You mean their MSVC from 2012. They only just added support for C99 with the latest release.

<comment><USER13> Because C is legacy on Windows. No need for C when there is C++, which also allows for safer systems programming.

The C99 subset that was added was what is required by C++11/C++14 standards and some key customers.

There are no plans for full ANSI C compliance, as discussed here

[http://channel9.msdn.com/Events/Visual-Studio/Connect- event-...](http://channel9.msdn.com/Events/Visual-Studio/Connect- event-2014/029)

[http://channel9.msdn.com/Events/Visual-Studio/Connect- event-...](http://channel9.msdn.com/Events/Visual-Studio/Connect- event-2014/311)

</comment></comment></comment><comment><USER14> Using unsigned ints everywhere seems like bad advice. Years may always be non- negative, but year1 - year2 won't be half the time.

And if it's modern C, why not use the typedefs from stdint.h?

<comment><USER15> If your result can be negative, use a signed integer. But in many cases you shouldn't: unsigned integers have well-defined behaviour, you should take advantage of that.

Also, while it's true that modern C has the stdint.h typedefs, the old types are still good. All of the standard library, and many libraries you use, use the old types, so this makes interaction with them more practical. Furthermore, it'd probably best to use sizes suited to your platform. A long will be 32-bit on a 32-bit system and 64-bit on a 64-bit system. You only need long long in some cases. You can't avoid the traditional C types for things like strings, either.

Really, stdint.h only matters if you're reading binary data or performance is ultra-important, IMO.

<comment><USER16> > A long will be 32-bit on a 32-bit system and 64-bit on a 64-bit system.

Not on Windows. Long is there always 32 bits.

<comment><USER15> Ah, yes, I should've noted that.

</comment></comment></comment></comment><comment><USER17> "Rule A C and C++ are different, don't mix them and don't mix them up." :D

</comment><comment><USER18> there is also 21st Century C: [http://shop.oreilly.com/product/0636920025108.do](http://shop.oreilly.com/product/0636920025108.do)

half of it is about tools (valgrind, make, autoconf) and it also talks about libraries (sqlite, gsl, etc...) of course there are some chapters about the language itself

<comment><USER19> How did you like that book? I was thinking about buying it, but a number of the reviews I read dampened my enthusiasm.

FWIW tptacek likes _C Interfaces and Implementations_ by Hanson, wonder how that compares.

<comment><USER20> > I was thinking about buying it, but a number of the reviews I read dampened > my enthusiasm.

A bit meta:

Looking for a book in a particular subject, I picked one because of a number of the reviews I read, but actually reading the book dampened my enthusiasm.

I don't know about this particular book, but if the subject is worth it it is probably also worth your time to check it out yourself :-).

</comment></comment></comment><comment><USER7> I enjoyed "Learn C the hard way" by Zed Shaw, but [http://hentenaar.com/dont- learn-c-the-wrong-way](http://hentenaar.com/dont-learn-c-the-wrong-way) kinda opened my eyes for some issues, and Zed seems to aggree ([https://twitter.com/zedshaw/status/562535244713058304](https://twitter.com/zedshaw/status/562535244713058304)) that the material needs a rewrite.

</comment><comment><USER21> I can't seem to copy/paste the code examples without it messing up the formatting. Can this be resolved?

</comment><comment><USER22> Is this a draft ? Section on Reetrancy seems to be missing ?

<comment><AUTHOR> It is a draft.

</comment></comment><comment><USER23> The book doesn't render properly in FF (but in Adobe Reader).

</comment><comment><USER24> I hate to be that guy, but I find the formatting very off putting -- especially with respect to the internal links. Compare to [https://github.com/sarabander/sicp-pdf](https://github.com/sarabander/sicp- pdf) , which I find visually pleasant.

<comment><USER25> The internal links framed by a colored box are the default rendering of the LaTeX hyperref package. I also don't like them, but they seem to be pretty common, e.g. most arXiv papers do that. You can turn it off by passing the 'hidelinks' parameter when loading the package.

</comment></comment><comment><USER26> The book claims that integer numbers wrap around. Thats not strictly true. According to the C spec the overflow behavior is undefined, how ever on all hardware known to man it wraps around. Why does it matter? Because some compilers may assume no wrap around ever happens and use this to optimize.

<comment><USER27> It only claims that for unsigned integers, which is true. It also correctly says that signed overflow is undefined.</comment></comment>


Mark Zuckerberg: Facebook Opposes SOPA/PIPA - <AUTHOR> https://www.facebook.com/zuck/posts/10100210345757211

<comment><AUTHOR> Here is the statement, in case login is required to view the post on Facebook:

 _The internet is the most powerful tool we have for creating a more open and connected world. We can't let poorly thought out laws get in the way of the internet's development. Facebook opposes SOPA and PIPA, and we will continue to oppose any laws that will hurt the internet.

The world today needs political leaders who are pro-internet. We have been working with many of these folks for months on better alternatives to these current proposals. I encourage you to learn more about these issues and tell your congressmen that you want them to be pro-internet.

You can read more about our views here: <https://www.facebook.com/FacebookDC?sk=app_329139750453932.*>

<comment><USER2> Login not required, I have FB login and widgets disabled and I can read it fine. Some of the commenters point out a good question here: why has Facebook not joined in with the blackout in some form? Or is it just US only, like Craigslist.</comment></comment>


Samsung attacks Galaxy S6 Edge bend-and-break tests - <AUTHOR> http://www.bbc.co.uk/news/technology-32201614

<comment><USER2> _" Some smartphones have different [levels of] durability in each [of their] front and back sides respectively. SquareTrade has only tested the front side, which may mislead consumers about the entire durability of smartphones."_

What a ridiculous argument. Someone should teach them about chains and weakest links.

</comment><comment><USER3> Marketing 101. Say it till someone else proves otherwise... then say something else.</comment>


Why Finland is good at handling forest fires. It's not because of raking - <AUTHOR> https://www.washingtonpost.com/world/2018/11/19/why-finland-is-so-good-handling-forest-fires-hint-its-not-because-raking/ <comment><USER2> Eh What utter shit is this? There are no "Controlled Burnings" in Finland anymore. Just meticulous collecting (aka raking) and mulching loose material from clear cutting. The material is used in energy production.

The problem elsewhere (eg Sweden and California) is the "Green Forestry" principles, which prevent removing excess biomass from forests, and at the sametime a policy to actively suppress forest fires is enforced. This leads to an overly accumulation of biomass in trees and forest floors, which in turn makes forests vulnerable to raging and fast moving forest fires, when critical amount of biomass has been accumulated.

As I recall "Controlled Burnings" were quite popular in 1950s in Finland expecially around railroads, because steam locomotives were such a fire hazard.</comment>


GCC 4.9 Will Make Compilers More Exciting In 2014 - <AUTHOR> http://www.phoronix.com/scan.php?page=news_item&px=MTQ5NjM <comment><USER2> Since the link is to phoronix I assume this is blog spam, could someone link the original? I've given up trying to find the number of technologies to disable to make phoronix and its multitudinous tracking bugs usable.</comment>


Do you have an ad-based revenue model? - <AUTHOR>

I'm astonished by the number of founders banking on ad-based model as the primary source of generating revenue. Does it really work for startups? What is your revenue model? <comment><USER2> I know. Look at all those crazies thinking they'll make money on ads. None of the big boys do that; just look at these recent top tech startups (reading through Alexa):

      Google
      MySpace
      YouTube
      Blogger
      fotolog
      Photobucket
      Flickr

Wait. Every single one of these startups is advertising supported. I wonder why people think advertising is a workable business model...</comment>


Show HN: Tech stories with lots of conversation in past 24 hours - <AUTHOR> http://knowabout.it

<comment><AUTHOR> At the moment the site mostly just monitors HN and reddit for new (tech related) posts that are getting a lot of comments in the past 24 hours...but if people find it useful, I may expand to monitor more sources (and offer a daily email digest)

<comment><USER2> Thank you, I like it.

Are you going to have an archives/history section so we can look back at the popular stories for a particular day?

<comment><AUTHOR> To move through archives just add the date to the overall url...example for Aug 21st -> [http://knowabout.it/08-21-2014](http://knowabout.it/08-21-2014)

<comment><USER3> What, no ISO 8601?!

How very US-centric.

[http://enwp.org/ISO_8601](http://enwp.org/ISO_8601)

<comment><AUTHOR> Sorry ;-)

</comment></comment></comment></comment></comment><comment><USER4> Nice! I could see myself using something like this.

Personally, I'd tweak the rankings a bit -- right now, all of the reddit posts are above the more-interesting HN articles. For me, an article with 100 points and 40 comments on HN is likely a more interesting story than a post in /r/Android with 200 comments.

Perhaps the ranking algorithm could be comments per audience-size?

<comment><USER5> _Perhaps the ranking algorithm could be comments per audience-size?_

the true next step would be a way to personalize rankings, even something simple as being able to filter out some topics

<comment><AUTHOR> Great suggestion...I'll think about the best way to implement this (without driving up the costs/processing too much). Thanks!

</comment></comment></comment><comment><USER6> This is reminiscent of what Engage.io was trying to do with its popular conversations feature before it shut down. I like the fact it focuses on tech conversations rather than conversations in general, there's so much more value to me in pre-filtering the content to a vertical I'm interested rather than trying to be everything for everyone. Great job, it's immediately engaging.

</comment><comment><USER7> It reminds me of Techmeme in a way. If you could group together stories that are alike (e.g. all of the Apple September 9th ones) and link to each discussion, it would be rather interesting (compared to Techmeme which focuses on all the authoritative sources discussing something, not communities like HN or Reddit).

<comment><USER8> I've been playing around with a somewhat similar project at [http://news.siliconfilter.com/](http://news.siliconfilter.com/) for the last few weeks. My biggest challenge was the grouping that I need to do in the background so I don't show multiple versions of the same story from different sites. I'm mostly using some basic text and link analysis for that. I think Techmeme does some of that by hand.

</comment></comment><comment> squeaky-clean Oh man, another place for me to waste time. This seems very cool, I'd love to see more sources added to it. I agree that the source and topic should be made more easily discernible. Once you add more sources, I could see it getting confusing.

A daily email digest would be a good idea for many users. I like to get involved in a discussion, though, but the digest would have to be sent after the discussions are over. Maybe a section for "rising" discussions if that's possible with how you've designed this?

I'll definitely try to use this next week as my time-waster.

<comment><AUTHOR> awesome ideas - will work on implementing. Thanks!

</comment></comment><comment><USER9> It's a nicely done site. It may just be my interest has diverged from generic tech news, but this looks like internet scale bikeshedding. It's not the biggest impact developments, or the biggest breakthroughs, it's the boring stuff that's relatable to a large number of people so it gets a lot of low quality comments.

<comment><AUTHOR> Thanks - _very_ valid points...but the idea of the service _is_ to make sure I can quickly/easily know about the things people are recently talking about (regardless of quality). The quality journalism that alerts us to the big breakthroughs and interesting stuff requires a more serious investment in resources I think ;-)

</comment></comment><comment><USER10> Make the source/topic more visually prominent. Many of these headlines don't make any sense without context.

<comment><AUTHOR> Good point - I'll work on getting better context into each link. Thanks!

</comment></comment><comment><USER11> Here's another test site for something similar: [http://www.informio.com](http://www.informio.com)

[Won't launch the project with tech though when finished]

</comment><comment><USER12> Nice, its about time someone re-invented the old Technorati concept. Doing sentiment analysis on news trends seems like such a useful idea, I'm really surprised there are more sites like this.

</comment><comment><USER13> Awesome! I was thinking of curating popular HN posts in a similar way, but with a little less frequency (higher threshold before it gets pushed to a feed or whatever). Very cool.

</comment><comment><USER14> It's all about android because it seemed ordered by the number of comments, you should average it by theme.

<comment><AUTHOR> Good point - my orig. motivation was just to get a quick list of stuff I'm too busy to catch (because I'm off coding during the day)...so I cared more about things _making_ the list than I did about the actual position on the list...but better grouping (like others mentioned) and better scoring (also mentioned by a few) is probably worth some time/focus...so I'm adding it to the list. Thanks!

</comment></comment><comment><USER15> Brilliant. But need to make UI more pleasing.

<comment><AUTHOR> I just released an update to the UI...would love to know if it's more pleasing for you. Thanks!

</comment></comment><comment><USER16> i am working on similar project, check : [http://tekh.me](http://tekh.me)</comment>


India-China to fight for top 2 positions this century, Masayoshi Son of SoftBank - <AUTHOR> http://tech.economictimes.indiatimes.com/news/internet/india-china-to-fight-for-top-two-positions-this-century-masayoshi-son-softbank-group/47778976

<comment><USER2> [http://opinionator.blogs.nytimes.com/2013/01/19/india-is- los...](http://opinionator.blogs.nytimes.com/2013/01/19/india-is-losing-the- race/)</comment>


Skewed VIEWS: The Huge Truth About Drake's Record-Breaking Chart Run - <AUTHOR> http://www.stereogum.com/1892123/skewed-views-the-huge-truth-about-drakes-record-breaking-chart-run/franchises/but-whos-buying/ <comment><AUTHOR> This is such a relevant topic, so well researched, and dare I say it - realistic in perspective - that it's a must read for anybody who cares about the streaming music business / model / market. Also, I recommend the other articles in the series, they have merit and similar rigor.</comment>


Ask HN: Ratio of points on HN to SO - <AUTHOR>

Stupid question of the day - what's your ratio of points here vs points on StackOverflow? <comment><USER2>
        35181 ÷ 430 = 81.81:1</comment>


Show HN: Incubator as a Service – we build, launch and test your employees ideas - <AUTHOR> I've been wanting to experiment with this for a while. It's a subscription service for companies that want to utilise the new product or service ideas their employees come up with.
With a fixed fee of $7500/mo, we'll basically work on up to 2 different ideas at the same time of your employees. This includes:
- Designing & Building an MVP - Validating the idea and get early signups - Talk to early beta testers and gather feedback - Keep the original team/employee in the loop and have him/her participate into guiding the product further.
When you decide the idea is ready for the next phase, you can build your own internal team or do so with our help.
Interested, contact is in my bio <comment> dane-pgp It's an interesting idea, and I hope it's successful, but I'm wondering if a similar business model is possible. Imagine a service where a company or individual could submit a suggestion for a product / app / service, with no upfront cost, and the receiving company would offer to create the MVP and generate revenue from it until they recouped their costs, then demand only a small percentage of all future sales / subscriptions.

The company offering this would obviously have to be very careful about which ideas it invested its resources in, because it would be taking all the risk, but for simple ideas the exposure would be quite small. Also, anyone using this service would want to be very clear about what "recouping their costs" means, so that there isn't any creative accounting going on. In practice, it might just end up as a way for one company to harvest a lot of barely profitable ideas, but that might be sustainable, and eventually they might bag a unicorn.

<comment><USER2> It's been said many times that ideas aren't worth much, implementation is. Chances are that shipping dozens and dozens of 'ideas' won't yield a sustainable business model.

<comment><USER3> The business model is implementing customer's ideas, or at least an MVP of them. They're monetizing the prototypes, not the ideas themselves.

<comment><USER4> There is no customer here if they're not paying.

</comment></comment></comment></comment><comment><USER5> The challenge that you will run into is the people problems.

Basically, doing new stuff and building an MVP is the fun work that many of your future client's employees would want to do. If you take on the fun work, then they may not be motivated to finish it.

Instead of building the MVP, it would be better to be a coaching service to help build up your client's employees ability to lead new projects. Provide marketing and complimentary support skills and teach the future leader what is possible and how to leverage others.

Independent of the actual results, a missing thing for many companies is the ability to build up leadership.

<comment><USER6> That's actually something I'm working on building - unlimited, on-demand management/leadership coaching for team leaders.

[http://LeadingUp.co](http://LeadingUp.co)

</comment></comment><comment><USER7> You're a dev firm on retainer. Also, it's creating more work for the principals involved. If it's a small org, they have neither time nor resources to do this to begin with, at medium org they might like it they might not, at the large orgs they would do it in house. So you end up targeting the same demo as every remote dev shop cold calling, competing against the boss's inclination that Fiverr would take care of it cheaper.

My suggestion is to take existing admin dashboard projects out there, integrate a few data sources for common use cases then sell that with the option to pay for dev hours to further customize.

Companies need more automation, data visualization, notification, reporting tools than anything else anyway.

</comment><comment><USER8> A well designed and written landing page selling me on this with previous project examples would have gone a long way...

</comment><comment><USER9> Not many companies would have budget for this.

I'm not even sure which part of the company finances it would come from... Maybe employee training?

</comment><comment><USER10> sounds like a dev shop but without an hourly rate. Monthly payment for some unknown amount of work.</comment>


Daquiri – logging for Python that works by default - <AUTHOR> https://julien.danjou.info/blog/python-logging-easy-with-daiquiri <comment><USER2> > Each time I write a new application, I need to remember how to set logging > up.

You mean, like this?

      import logging.config
      import yaml

      with open(log_config_file) as f:
          logging.config.dictConfig(yaml.safe_load(f))

Because this is _the_ correct way that allows the user to supply their own configuration that is not tied tightly to your little program.</comment>


Show HN: What does it feel like to be one of 7 billion? (built with D3) - <AUTHOR> http://blog.vctr.me/experiments/7billion.html

<comment><USER2> Great work, but would be great for a frame of reference to add something at the end that zooms back out (and maybe uses a different scale to fit on screen) that shows you against everything.

As soon as I discovered to click to go to the next tier, I just kept clicking and didn't pay attention to how many levels, how many people, etc.

Otherwise great work!

</comment><comment><USER3> It feels like "we're alone in the Universe".

</comment><comment><USER4> neat project!

<comment><AUTHOR> ty :)</comment></comment>


Facebook fugitive attached GPS monitor to a "motorized contraption" - <AUTHOR> http://arstechnica.com/tech-policy/2015/03/facebook-fugitive-attached-gps-monitor-to-a-motorized-contraption/

<comment><USER2> 40 years sounds like an awful brutal sentence hanging over this man's head.

Then again, the accusation is that he forged documents and emails, and deleted others, as part of a lawsuit. That seems pretty bad.

But 40 years literally takes someone's life away. The crime was nonviolent. Maybe 10 years in jail would be a harsh enough penalty? That's pretty life- changing. I suppose it's up to the judge, maybe if he wasn't using crazy methods to flee from bail he wouldn't end up with the max penalty. Seems like he's screwed now.

This whole thing makes me uncomfortable.

<comment><USER3> Seriously. I don't get how a non violent crime like this gets more jail time then if someone was a heroin selling murderer.

<comment><USER4> Welcome to the wonderful world of federal overcriminalization.

Aaron Swartz faced 13 federal felonies (the Feds upped it from 4 to 13 at some point) and a possible maximum of 50+ years in prison: [https://www.techdirt.com/articles/20120917/17393320412/us- go...](https://www.techdirt.com/articles/20120917/17393320412/us-government- ups-felony-count-jstoraaron-swartz-case-four-to-thirteen.shtml)

Then there's the No Electronic Theft Act, which Clinton signed into law. It made not-for-profit copyright infringement -- think sharing on P2P networks -- a federal felony. Previously it was a civil matter.

Now <gvb> is correct that there are sentencing guidelines that will make the _likely_ sentence less. But even the outside possibility of a young man or woman leaving prison when they're 70-80+ years old for a non-violent crime is remarkable. (Note I'm not defending Paul Ceglia, who may well have committed fraud and should pay the price if convicted; I'm merely saying that the punishment should correspond to the gravity of the offense.)

These are DOJ stats for the year 2000, but it gives you an idea of the range for violent felonies: "The mean prison sentence for murder and nonnegligent manslaughter was nearly 20 years and 8 months." [http://www.bjs.gov/content/pub/ascii/Fssc00.txt](http://www.bjs.gov/content/pub/ascii/Fssc00.txt)

Harvey Silverglate's book "Three Felonies a Day" is an excellent resource, and I separately wrote about the overcriminalization of federal law here: [http://www.cnet.com/news/from-wargames-to-aaron-swartz- how-u...](http://www.cnet.com/news/from-wargames-to-aaron-swartz-how-u-s-anti- hacking-law-went-astray/)

<comment><USER5> Declan, you know you're oversimplifying the Swartz case. We've discussed this before. You are technically correct that the gap between "likely" and "possible" is decades, but that outlandish "possible" is, well, outlandish.

The difference between the 7 months Swartz was threatened with by prosecutors and "50 years" is the question of whether multiple CFAA counts for the same crime "group". We know the answer to this: they do. Defendants convicted on multiple counts of CFAA offenses for the same underlying criminal act serve a sentence for a single count (the most severe). A judge could override this, but the onus should be on the "50 years" people to cite a CFAA case in which a judge has ever manipulated CFAA grouping rules to amp up a sentence. The argument seems to suggest that a judge might be so upset by Swartz that they'd _throw out a chunk of the sentencing guidelines_.

 _Swartz 's own attorney_ wrote, after his death, that a conviction on all counts might still leave Swartz at a sentencing level that allowed probation: his crime was non-remunerative, the statute he was charged on is oriented heavily towards financial crimes, his primary victim was unmotivated, and he had no criminal record.

When Swartz's sentence is brought up on a message board, what's really being discussed is the nature of judicial discretion versus the federal sentencing guidelines.

That's unfortunate. Leaving aside the fact that any custodial sentence for Swartz would have miscarried justice, and beyond the trauma of enduring a federal criminal prosecution, the likely guideline sentence for Swartz's charge (if you stipulate that he was guilty, which you can't do here) is not prima facie insane.

But other CFAA sentences _are totally insane_. When you handwave around Swartz's sentence, you make it easy for people who understand (at least a bit about) federal sentencing to laugh off other CFAA sentences. But there have been recent cases in which the CFAA's sentencing process is much more clearly unjust.

<comment><USER4> <tptacek>: Yes, we've been around this circle before, and I don't think we're going to change each other's minds.

As for Aaron Swartz's attorneys, they would have jumped at the chance for probation. They explicitly offered it as a deal to the Feds, who rejected it. Prosecutors held out for a felony plea and prison time: [http://www.thedailybeast.com/articles/2013/01/15/aaron- swart...](http://www.thedailybeast.com/articles/2013/01/15/aaron-swartz-s- unbending-prosecutors-insisted-on-prison-time.html)

So because of the combination of federal overcriminalization (thank you, Congress) and prosecutorial overzealousness (thank you, Carmen Ortiz), this is what Aaron had to look forward to:

 _If he plead guilty to a felony, he could have been sentenced to as many as 5 years... Each additional conviction would increase the cap by 5 years, though the guidelines calculation would remain the same. No wonder he didn 't want to plead to 13 felonies. Also, Aaron would have had to swear under oath that he committed a crime, something he did not actually believe._ [http://cyberlaw.stanford.edu/blog/2013/01/towards- learning-l...](http://cyberlaw.stanford.edu/blog/2013/01/towards-learning- losing-aaron-swartz-part-2)

<comment><USER5> Did you read her whole post? The hypothetical you're referring to is preceded by a paragraph that ends with "But Aaron could easily have come out to over a year in his guideline calculation" in the case where he went to trial and was found guilty.

</comment></comment></comment></comment></comment></comment><comment><USER6> I work in the correction industry with devices like this one. Most devices don't have accelerometers in them so so the "motorized contraption" would not be needed, the picture is too blurry for me to make out what brand of ankle bracelet this is or I could tell you if it has one. GPS drift would make it impossible to tell if someone is moving in their house (Normally looking at GPS points shows a clustering around the house and sometimes as far as a 50+ meters outside their house.

As to those asking how he got it off, the article says it was "sliced" off so my guess is he cut the strap (then lied about the fall) which cut the fiber optic cable in the bracelet, he then reattached the fiber optic cable and taped it up. The police SHOULD have been sent as soon as they got a strap tamper alert but it appears they believed the fall story. Note most of the time police don't talk to the participants when this happens, rather a monitoring company staffs a call center then send recording of the call and notes to the user's supervisor who then can choose to alert the police. Apparently there is another way to get these off if the bracelet is loose enough that involves a plastic bag and sliding it off (a co-worker mentioned a video going around of it but I've never seen it) but due to the fact this article mentions they were alerted to it being tampered with I doubt that is the case.

</comment><comment><USER7> If all he needed to do was to show some movement of the tracker, he could have just duct-taped it to a Roomba. He'd get much more realistic motion with much less effort.

<comment><USER8> Great idea except for the battery life. He presumably wanted more than a few hours of activity.

<comment><USER9> Doesn't roomba charge itself and then go for another run?

<comment><AUTHOR> This issue is charging the ankle bracelet, not the roomba (which connects itself to a charger as you point out).

<comment><USER10> Well, I guess you could plug the bracelet to a power source with a long cord.

</comment></comment></comment></comment></comment><comment><USER11> Like the scene in Home Alone where the kid puts cardboard cutouts on a model train set, to make the burglars think there's a party happening at the house. :)

Edit: I guess that scene was more elaborate than I remembered: [https://www.youtube.com/watch?v=LHOuoJmcozk#t=2m13s](https://www.youtube.com/watch?v=LHOuoJmcozk#t=2m13s)

<comment><USER12> Apparently there isn't a lot of "Get Smart" on YouTube or else I could have pointed to that ~20 years earlier.

</comment></comment><comment><USER13> Why is this even a criminal case? Could a civil court not just chuck out the idiotic claim on the lower 'balance of probabilities' test?

<comment><USER14> The criminal case was brought against Ceglia when it became apparent that his claims to a stake in Facebook were based on forged documents. That's fraud; it's a criminal offense.

<comment><USER15> It's interesting that the big law firms like DLA Piper[0] who backed him pro bono and conducted "extensive due diligence" on his claims walked away without even much of a tarnished reputation.

[0] Facebook are suing them. [http://abovethelaw.com/2014/10/lawsuit-of-the- day-facebook-s...](http://abovethelaw.com/2014/10/lawsuit-of-the-day-facebook- sues-dla-piper/)

<comment><USER13> Thanks to grandparent for clarification. Allegedly forging documents will get you in trouble quickly certainly. I suppose it depends on the resources the big law firm has for spotting forgery.

</comment></comment></comment></comment><comment><AUTHOR> I wonder how he got the bracelet off of his ankle, without setting off an alarm.

<comment><USER16> It says in the article that the police were alerted to bracelet tampering: "The filing said the authorities got suspicious that something was awry with the GPS device on March 6. An agent spoke with Ceglia on the phone and "Ceglia reported that the bracelet had been damaged in a fall." But the agent said it subsequently was "functioning properly" until the next day."

<comment><USER8> This implies that these things must throw false alarms with some regularity, otherwise this would have been a huge red flag and they wouldn't have hesitated to follow up immediately.

<comment><USER12> This seems likely. Even if you get him on the phone, you could have an officer drive by sometime in the next day to visually inspect that the ankle bracelet is still there.

(Of course I would get a second bracelet and strap a dummy one to my leg to show to the officer. Officer would need some way of verifying he's seeing the right one.)

</comment></comment></comment></comment><comment><USER17> Everything else aside, this is a beautifully executed hack.

</comment><comment><USER18> Why not attach it to the dog? Or a Roomba?</comment>


Ask HN: Retainer ideas for a designer - <AUTHOR> As a developer, one could host a webapp and charge for a retainer (with hardly any ongoing work). As a designer, I'm wondering if there's something (besides a retainer for ongoing work...) that I could charge clients for without me having to do extra work. <comment><USER2> A client of mine had a designer on a retainer. They're a mail order business and would sometimes get very last minute offers on ad space just as magazines were going to press - and the designer had to be available to crank out a print ad with their very latest offers at very short notice. Unfortunately they stopped print advertising in the end and he was let go.

They do send a lot of marketing emails but employ someone in-house to design those nowadays (who also handles the limited print ads that they still run).

<comment><USER3> Do this. Look for clients that regularly run banner ads or similar (or offer services / run ads yourself based on that offering). Offer X amount of time, or up to X ads per month - whatever is fair for your price. Some clients will use it all, some clients are just happy to have a designer on hand who can whip up what's needed (so money for very little).

Similarly, just offer clients retainer work. X amount per month, but you'll jump for them when needed. Example: we just had to get a designer to put something together for a really quick project. They were literally on call, turned it round in about 6 hours. Some months that's how it goes - a lot of work for not much. But other months they may not get a call.

<comment><USER4> There was lastly some guy or girl at HN who talked about his or her company which does precisely what you say as a service! Don't know name anymore

</comment></comment></comment><comment><USER5> I'm unclear what you are after - are you asking us to help justify charging them for nothing, just because you did work for them in the past? Like, a license fee for continuing to use your designs? Or are you asking what services could be provided on a monthly basis that don't require actual work?

</comment><comment><USER6> We don't charge a retainer, but do bill in advance. This can solve a lot of cash flow issues, and even out your billings. I've written about this approach here: [http://www.erickarjaluoto.com/blog/how-we-fixed-our- studios-...](http://www.erickarjaluoto.com/blog/how-we-fixed-our-studios-cash- flow-problem/)

</comment><comment><USER7> \- "As a developer, one could host a webapp and charge for a retainer (with hardly any ongoing work)"

This is not really true. Depending on the stack / type of project, there is a number of things you do on regular basis to maintain a project. People are bad at technology and a lot of it for me is usually fixing human error (especially CMS driven projects).

Also, the one time something breaks and the developer has to spend time rectifying the issue is spread out as a cost across a number of payments.

Not just a rant - there is an answer in what I've said - value is offered as part of the retainer. Client receives the peace of mind they need and doesn't have to worry about having to find someone to fight fires, when they do eventually hit.

Find things that offer value, be it peace of mind or something else, and upsell towards the end of your projects.

<comment><USER8> This. I use a service to keep two servers online. _They_ worry about updates, security issues, and what-not. If I want to know if the latest $OhChristWhatNow affects me, I don't have to deep-dive the forums. I email my service- they're on it.

I deal with other servers, but leave these biggees to the full-time pros.

</comment></comment><comment><USER9> You could partner with a developer and create some themes and sell them in theme marketplaces. That's one way designers can make scalable recurring revenue. Most of the customer support will be on the developer's side to solve bugs and installation problems.

</comment><comment><USER10> There's the opportunity for retainer for the _possibility_ of additional work. (If they need you, you have taken that money in order to have availability for them.)

</comment><comment><USER11> This question is confusing. It sounds like you just want money without providing value. I would worry less about that part. Figure out something you can actually provide first without thinking about the free money, maybe a-lot x hours a month for providing additional digital assets (you made their logo but if they need it in different sizes, colors, svg, included with a picture, facebook banner, google business, some advertisement, etc) that might have value if they can't do that themselves or don't have the time. It's almost always the later.

</comment><comment><USER12> The key to getting a retainer irrespective of being a programmer, designer, or gardener is client selection. For a designer, one obvious route to passive income is licensing fees. But again, finding clients that will be happy to pay such fees is the bigger problem in a world where many people will assume they own the designer's design by virtue of commissioning the work.

Good luck.

</comment><comment><USER13> A retainer is a liability on your books. When the relationship ends, you pay it back. The purpose is to give you the money needed to do what's necessary, basically prepaid work. Also, it should make it clear that the client's work is priority over work not yet contracted.

</comment><comment><USER14> Anytime I've ever charged a retainer, it's been because there has been ongoing work and they've needed me to be available at short notice. A retainer acts as a little bonus to keep me from giving another gig higher priority.

</comment><comment><USER15> I'd pay a designer for retainer. We have a designer we work with at the moment who is great and I have ongoing needs. Woudl be easier to send bits and pieces as we need them instead of batching.

</comment><comment><USER16> Create visual assets that can be reused (templates, logos, icons, illustrations) and sell those on various marketplaces? Apply subscription model licensing to the designs you create for clients?

</comment><comment><USER17> Are you talking about a royalty?

</comment><comment><USER18> What's in it for your clients?

</comment><comment><USER19> Doing work rocks</comment>


Bash aliases for Django - <AUTHOR> https://github.com/algotech/dotaliases/blob/master/doc/bash/django_aliases.md <comment><USER2> If that's your thing, I just wrote a long blog post on using Make with Django: [https://thraxil.org/users/anders/posts/2016/03/03/Using- Make...](https://thraxil.org/users/anders/posts/2016/03/03/Using-Make-with- Django/)</comment>


An Intensive Introduction to Cryptography - <AUTHOR> https://www.intensecrypto.org/public/ <comment><USER2> Another great crypto resource (though it's really an intro course) that's out there is the Cryptography course on Coursera: [https://www.coursera.org/learn/crypto](https://www.coursera.org/learn/crypto). It's taught by Dan Boneh who, in addition to being a genius, also happens to be incredibly talented at explaining crypto concepts in a way that leads to deep understanding. It's a great treat watching him write out and explain different proofs from memory.

After taking these two crypto courses, I signed up for CS155 [https://crypto.stanford.edu/cs155/](https://crypto.stanford.edu/cs155/), which is his undergrad class on security at Stanford (they were offering it through their professional center, I don't think they still offer it, which is a bummer)

</comment><comment><USER3> On the other side of the spectrum, The Manga Guide to Cryptography came out recently, if that's more your style: [https://nostarch.com/mangacrypto](https://nostarch.com/mangacrypto)

<comment><USER4> The Manga Guide series has been surprisingly good in general. Not the most in depth stuff but generally quality intro texts.

Unfortunately from the preview the typesetting of the English translation in the new crypto book looks awful. Hopefully the actual content is still of good quality.

<comment><USER5> Unfortunately there are missing exponents on some of the calculations.

</comment></comment></comment><comment> Ar-Curunir This is a class for folks trying to understand the theory behind modern cryptography rigorously; it focuses on the theoretical foundations of crypto like one way functions and PRGs and builds up from them.

This course will not teach you how to implement crypto, but the material here is incredibly important to understanding the abstractions and reasoning behind modern cryptographic constructions, and is a prerequisite to becoming good at implementation aspects of crypto.

</comment><comment><USER6> a word of warning. off the page textbook crypto _examples_ are not a good crypto scheme you have to think like a bank robber to start securing your bank. if you think like a banker then you will try to cut costs and corners to make revenue.

addendum > _Anyone, from the most clueless amateur to the best cryptographer, can create an algorithm that he himself can 't break. It's not even hard. What is hard is creating an algorithm that no one else can break, even after years of analysis. And the only way to prove that is to subject the algorithm to years of analysis by the best cryptographers around._

good crypto cant be broken by knowing the algo thats why closed proprietary crypto is POS

addendum 2 )

this makes the case for open source so there are multiple perspectives rather than _ECHO CHAMBERS_ bcz when it comes down to it you can talk yourself into thinking anything is great when it is your own pet theory.

BTW im working around the posting too fast BS so thats why the addendums to parent post.

</comment><comment></comment><comment></comment><comment></comment><comment></comment><comment>=== ALSO off topic but, concerning:

Detecting Screen Content via Remote Acoustic Side Channels

{[https://www.cs.tau.ac.il/~tromer/synesthesia/](https://www.cs.tau.ac.il/~tromer/synesthesia/)}

every time a pixel changes it makes a UHF+ EMF _chirp_ every time a bus channel makes a bit state transition it makes a UHF+ _chirp_ if you evesdrop the EMF radiation preserve it and analyse your data then you can reconstruct _EVERYTHING_ that the hardware is doing not just the display screen.

<comment><USER7> Although be wary of how far even that can take you. As Bruce Schneier has said[0]:

> Anyone, from the most clueless amateur to the best cryptographer, can create > an algorithm that he himself can't break. It's not even hard. What is hard > is creating an algorithm that no one else can break, even after years of > analysis. And the only way to prove that is to subject the algorithm to > years of analysis by the best cryptographers around.

> If I have any contribution to this, it's to generalize it to security > systems and not just to cryptographic algorithms. Because anyone can design > a security system that he cannot break, evaluating the security credentials > of the designer is an essential aspect of evaluating the system's security.

[0] [https://www.schneier.com/blog/archives/2011/04/schneiers_law...](https://www.schneier.com/blog/archives/2011/04/schneiers_law.html)

</comment></comment><comment><USER8> What is a typical path for those who want to follow this as a career? Is it mostly PhDs in academia? Or governments? Or industries? How do they fall as a distribution?

<comment><USER9> I worked on the Windows crypto team for a few years. Learned a ton about this area. Most of the work, however, is plumbing. Only a tiny fraction of crypto work is actually on algorithms and that's mostly performance related.

<comment> tom-c The interesting thing about Crypto performance tuning is that you really have to ensure that no logical path does a different amount/kind of work than another(i.e. no short circuiting). I used to not think much of it until I saw an RSA private key recovered via acoustic analysis of capacitor whine due to a short circuit condition in a function to multiply two large numbers.(this was using a recent release of openssl) To my knowledge no other area of programming really has this pitfall

<comment><USER10> If this "I saw" has any further public details, I'd absolutely love to learn more, and I'm pretty sure others would as well.

In particular, I'm especially interested in electrical or real-world attacks - such as capacitor whine! - that can be applied a weakened security situations like asymmetric logic/branching. I vaguely recall CPU voltage fuzzing is a thing, I want to go learn more about that at some point.

I'm only familiar with eg ultrasonic accoustic airgap attacks (like MOSQUITO, eg [https://securityaffairs.co/wordpress/70192/hacking/mosquito-...](https://securityaffairs.co/wordpress/70192/hacking/mosquito- attack-airgapped-networks.html)).

<comment><USER11> For the specific case of acoustic signals, see [https://www.tau.ac.il/~tromer/acoustic/](https://www.tau.ac.il/~tromer/acoustic/). For "CPU voltage fuzzing", Google "glitch attack" (e.g. [https://wiki.newae.com/Tutorial_A2_Introduction_to_Glitch_At...](https://wiki.newae.com/Tutorial_A2_Introduction_to_Glitch_Attacks_\(including_Glitch_Explorer\)) ) or, more generally, "fault attacks".

The relevant academic community can be found around [https://ches.iacr.org/2018/program.shtml](https://ches.iacr.org/2018/program.shtml).

(I work for a company building high-assurance crypto appliances for the Dutch government, so I have a professional interest.)

</comment></comment></comment></comment></comment><comment><USER12> For those looking to get working knowledge of modern cryptography, I recommend [https://www.amazon.com/Serious-Cryptography-Practical- Introd...](https://www.amazon.com/Serious-Cryptography-Practical-Introduction- Encryption/dp/1593278268)

I've been working my way through it and it's the most lucid intro text I've read on the subject.

</comment><comment><USER13> Was this created with Idyll ?

[https://idyll-lang.org](https://idyll-lang.org)

<comment><USER14> My guess would be that it was created in Bookdown with the Tufte handout style[0]

[0] [https://bookdown.org/yihui/rmarkdown/tufte- handouts.html](https://bookdown.org/yihui/rmarkdown/tufte-handouts.html)

<comment><USER15> It looks like the author used pandoc with Tufte handout

* css: [https://github.com/edwardtufte/et-book/](https://github.com/edwardtufte/et-book/)

* latex: tufte-handout style from CTAN</comment></comment></comment>


Women who clean at home or work face increased lung function decline - <AUTHOR> https://eurekalert.org/pub_releases/2018-02/ats-wwc021318.php <comment><USER2> Not sure why this struck a nerve with me but this is really shitty reporting. I guess because the site labeled itself as science news but the article is all confirmation bias and correlation v causation.

On entry to the article of course it seems like common sense that breathing in what could boil down to chlorine gas (bleaches) and peroxide mist etc would be bad for you.

But the entire article is then trying to fit a poorly designed and sampled study to that common sense. By the time you get to the end of the article where there was no measured effect in men, I don't think the collected data supports any of the color commentary.

It would be interesting to see a properly sampled study in a country like the US with wider socioeconomic gradient and crosscutting clean v non-cleaners.

<comment><AUTHOR> Bad reporting?

It does a pretty good job explaining what was analyzed in the study. It talks about negative results (i.e. no effect in men, no COPD), and at the end of the article it discusses the limitations.

It is a Eureka report--It's a press release that I think is usually written by the researchers themselves or the University.

Is the science valid? Maybe, maybe not. But I do not perceive this as bad reporting

</comment></comment><comment><USER3> I recently bought a robotic vacuum cleaner; I'd vacuum normally about once a week, and it seemed that I'd need to vacuum more often, because the dust gathers everywhere; having not the time or the inclination to bring out the heavy hoover, I decided to buy a robot one.

It is the best investition in the last 12 months, by far. It goes around automatically each day and keeps the floor clean. But that's not impresses me. What I'm impressed about the the level of dust that it accumulates each day. I'd expect each day to be a bit less, but no, it's about the same. So I set out to figure out where the dust comes from, as I live in a clean area of the city, surrounded by trees and greenery.

To my shock, it's us. The dust is primarily decomposed skin and clothes chafing off due to the skin friction. I can't imagine how damaging this is to our lungs, of course, nothing compared to chemicals or coal dust, but still...

I can't recommend enough to everybody to buy a robotic vacuum cleaner these days. I bought a cheap Eufy, and I can't imagine what a more expensive one would actually do more than this one.

<comment><USER4> After reading about the house mapping of some robotic vacuum cleaners I'm hesitant to let one into my home.

<comment><USER5> ... Why? What's so confidential about your floor plan?

<comment><USER6> Could you send me a detailed copy of your floor plan? Ideally, SVG? Thanks! Oh, and anything else the robot sends too, like your IP address and maybe GPS coordinates?

If you're willing to send, great -- thank you. I'd love to know, for undisclosed reasons. My email is in my profile, and you can even encrypt the files you send me using PGP. Although note that I'll be putting it on my Azure account and leaving it there for eternity.

If you're not willing to send me that, then please don't even try the "you've got nothing to hide" line, because you clearly do! I'm going to start challenging this every time I hear this excuse because it's demonstrably nonsense when challenged.

You won't send me that SVG because you know I have no fucking business knowing what your house looks like. Neither does the robot cleaning company. The files could be kept on the device without any real loss of functionality. As Washuu posted below, they are now selling these floor plans. Should I make money off the floor plan you send me?

<comment> shaki-dora

         |-=-=-|
         |     |
         | LR  |
         |     |
         |-- --|
         |     |
         *     |
         |-- - |
         |   |B|
         |   |R|
         |   |-|
        ||     |
        ||Kitch|
         |     |
         |     |
         |-- --|
         |     |
        ||     ||
        || BR  ||
         |     |
         |-==--|

All rather approximate. Each - is about 1m. * is main door. Address is Laustizer Str. 24, Berlin. Second Floor on the left.

<comment><USER7> I noticed that entire building facades on your street are hidden in Google Street View ([https://imgur.com/a/NzDZP](https://imgur.com/a/NzDZP)).

I'm curious why is that so? Is it possible due to GDPR?

<comment><USER8> Way older than GDPR, opting out has been possible for Streetview as long as it is available in Germany. Many people didn't like the idea of Streetview, and the legal status isn't entirely clear (exceptions for photography in public are fairly limited in Germany), so Google added this instead of risking larger PR and legal problems.

</comment></comment></comment></comment></comment></comment></comment><comment><USER9> If this worries you, here's a cleaning tip for cleaning your tub with much better results and much less effort.

In a spray bottle, mix 1/2 vinegar and 1/2 unscented dish detergent. Spray your shower/tub down with the mixture, including shower curtain. Walk away. In 30 minutes rinse off. You'll never use one of those industrial scented cleaners to do this again.

<comment><USER10> Or, you know, simply use soap and water in a small bucket, which is much less likely to be inhaled and will smell much better. Sometimes just water will work. You can also steam clean with plain water. These will clean most things, including windows if you use a squeegee. Simply wiping with water will make things appear clean, and magic erasers (soap free) can be used for stubborn stains.

Tubs and showers aren't generally a problem if you rinse and squeegee after you are done. Curtains are a pain, but doors are similar. Plain dishsoap takes off soap scum.

<comment><USER9> Absolutely. Squeegee after use also helps a lot.

If you get mildew, using a squeegee will usually prevent that. To get rid of it, though, use fresh hydrogen peroxide instead of bleach.

The vinegar/dish detergent mixture really gets the soap scum, though.

</comment></comment></comment><comment><USER11> I wonder if there is a similar effect observed in people who cook regularly - especially at high temps or in poorly ventilated spaces. Cleaning the exterior and filters of the exhaust cabinet makes me wonder about the interiors, of, for instance, apartment dwellers doing wok frying.

<comment> def- "Chinese food cooking and lung cancer in women nonsmokers." [https://academic.oup.com/aje/article- pdf/151/2/140/272296/15...](https://academic.oup.com/aje/article- pdf/151/2/140/272296/151-2-140.pdf)

> This study presents evidence that cooking habits are associated with lung > cancer in Taiwanese women nonsmokers. As shown in this and our earlier study > (1), women who do not use fume extractors during cooking are at high risk of > developing lung cancer. Furthermore, women who wait until the oil has > reached a high temperature before cooking the food (stir frying, frying, and > deep frying) and do not use a fume extractor have a consistently higher risk > of lung cancer when compared with both hospital and community controls.

and further:

> In Taiwan, the market for vegetable oil increased from less than 50 percent > to 85 percent between 1950 and 1990. However, vegetable oil containing > unsaturated fatty acids was found to be more unstable than lard oil at > higher temperatures and could emit benzoapyrene, which was not found in lard > oil fumes (26).

</comment></comment><comment><USER12> I heard someone on the radio, possibly one of the authors, discuss this and they seemed to be emphasising aerosol sprays that produced very small droplets rather than cleaning chemicals generally.

</comment><comment><USER13> Can this be solved by just wearing a face mask?

Why don't we wear face masks when cleaning?

Edit: face mask not meat mask!

<comment><USER14> In theory, an N95 mask should work. At its weak spot - .1 microns or so - it's still 95% effective. It's been shown to be 95% vs NaCl, which is smaller than bleach (NaOCl).

But in personal experience, whenever I finish up with a patient in contact isolation, I use bleach wipes on my steth. Not only does the odor strongly penetrate the mask, but by mitigating the dilution effect of free air flow, I honestly feel like it concentrates more of the crap inside the mask.

For whatever anecdote is worth.

</comment></comment><comment><USER15> also, see a longer discussion at "Deodorants, perfumes, soaps pollute air at levels as high as cars": [https://news.ycombinator.com/item?id=16395372](https://news.ycombinator.com/item?id=16395372)

i wouldn't be surprised if the same held true for cleaning agents.

</comment><comment><USER16> > The number of men who worked as occupational cleaners was also small, and > their exposure to cleaning agents was likely different from that of women > working as cleaning professionals.

I don't understand this. How being a male working as cleaning professional will get a different exposure to cleaning agents? It's the same job, with the same chemicals.

A family member working in the construction business told me that it was also the case for construction worker, they were dying much younger than the average, because of exposure to airborn particles from paint, concrete, asbestos, dust, wood and other various chemicals.

</comment><comment><USER17> Miners with "black lung" didn't need a study or scientists to tell them about it.

<comment><USER18> And yet scientists still did a totally "unnecessary" study about them [1], because _today_ miners are dying at younger ages than they did in the past and that's a troubling conclusion that you wouldn't immediately guess from annectoda.

Science is important, even for the 'its obvious, everyone knows it is dangerous' kinda stuff.

[1] [https://www.cdc.gov/mmwr/volumes/65/wr/mm6549a1.htm](https://www.cdc.gov/mmwr/volumes/65/wr/mm6549a1.htm)

<comment><USER19> > Science is important, even for the 'its obvious, everyone knows it is > dangerous' kinda stuff.

Indeed. Intuition, or in other words the "well, that's obvious" feeling, might be a good lazy approximation of the truth, but it is often wrong when examined closely.

<comment><USER20> > ... but it is often wrong when examined closely.

Having witnessed the whiplash in scientific understanding I'd almost say that "it's more complicated than that" is a more accurate summation. Since often the approximation isn't totally wrong but it's more a simplification of the issue.

</comment></comment></comment></comment><comment><USER21> So what's the solution? Wear a Asia style face/dust mask while cleaning?

<comment><AUTHOR> That won't stop submicron sized particles

</comment></comment><comment><USER22> can we finally offer scientific explanation for why we rarely clean our apartments??

<comment><USER23> No wonder I always felt so miserable when I had to clean!

</comment></comment><comment><USER24> Nowadays everything kills you...sitting at your desk at work, cleaning at home....

<comment><USER25> People said the same thing about sun exposure and smoking half a century ago.

<comment><USER26> So? His point still stands.

If you want to maximize your life expectation, you have to restrict yourself quite a lot.

And I think the goal of studies like this should not be to say "don't use it, it kills you" but rather to make us find a better alternative.

<comment><USER27> In terms of absolute physical harm, yes.

If you live with other people you probably need to convince them to do things differently too.

In my experience this can be very stressful and I wonder if the induced stress of even worse for ones health.

</comment></comment></comment></comment><comment><USER28> Women, but not men? So nobody should clean? Is it just me experiencing this gender bias cognitive dissonance? For me this renders the whole study suspect and dodgy: if they missed this Elephant In The Room bias, what other, more subtle, issues might they have missed/ignored/swept under the rug?

<comment><USER29> Actually it should say "European Women" rather than just "Women"

<comment><USER30> If you're going to be pedantic, at least go all the way: "3,298 European Women"</comment></comment></comment>


Show HN: Super Easy Forms (free) – The best way to create HTML contact forms - <AUTHOR> https://supereasyforms.com/ <comment><AUTHOR> We developed this tool as a gift for the community. Contact forms should be easy and free to make. Some of what makes us different - Features:

100% customizable html forms (No iframes) Create an unlimited amount of forms Store unlimited form submissions Register an unlimited amount of emails. Easily export submissions from the database

Please download and use Super Easy Forms. Feedback is welcomed =)</comment>