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To Really Cut Emissions, We Need Electric Buses, Not Just Electric Cars

rover42 Super-capacitors? (486 comments)

Shanghai has had some buses using these for several years. They recharge at some of the bus stops.

about two weeks ago

Google Offers a Million Bucks For a Better Inverter

rover42 Weird restrictions (260 comments)

They exclude people in various places from entering. https://www.littleboxchallenge... I can see why Cuba, Iran, N Korea, Syria & Sudan are listed. But why on Earth are Brazil, Italy & Quebec on the list?

about 2 months ago

Ask Slashdot: Beginner To Intermediate Programming Projects?

rover42 Text-scanning programs (172 comments)

You want to use Python, which is a good language for text manipulation. That suggests various projects based on scanning through text. Take any interesting large piece of open source software. How many switch() statements lack a default: case for error handling? You can get a first approximation with a few lines of shell & grep, but doing it right would need a language like Python and a moderate amount of work. What else would be easy to check? Take text samples from several different news sources. How do their vocabulary choices differ? Does that indicate their political biases? Can you program some of the standard indicators of reading level (see Wikipedia)? Do they get different scores?

about 4 months ago

Ask Slashdot: Beginner To Intermediate Programming Projects?

rover42 Try some classic problems? (172 comments)

There are a number of problems that are often used as exercises. Textbooks at any level from high school to grad school have examples; here are a few off the top of my head: Games: start with something really easy like tic-tac-toe, then try more interesting games. 8 queens: put 8 queens on a chessboard so that none of them checks any other. The easy version is to just find one solution. It gets a lot harder if you want to do it efficiently and/or find all possible solutions. Doing it in reasonable time for N queens on an N by N board is really hard. Markov chains: Analyze some large sample of text to count how often combinations of words or letters turn up. Then write a program to generate text using those statistics. How long a chain do you need to look at to get more-or-less sensible output?

about 4 months ago

Industry-Wide Smartphone "Kill Switch" Closer To Reality

rover42 What will it be used for? (139 comments)

Will the companies start killing phones if there is an overdue or disputed bill? If you unlock or jailbreak a phone? If this bill is passed without really strong consumer protections built in, it could be a disaster.

about 5 months ago

Ask Slashdot: What Do You Do If You're Given a Broken Project?

rover42 Instrument the code (308 comments)

As others have suggested, talk to the original developer, document the problems and keep your boss informed. If you are a contractor being supplied by one firm to another, keep the appropriate people at both companies informed. Also, look for ways to measure the problems. First, can you run the code through lint(1) or crank the compiler options up to reveal problems? Then can you add runtime error checking or data validation code? This may help you fix things and/or be useful as documentation. Once, when working as a tech writer, I wrote a half a dozen little scripts to inspect 600,000 lines of C from a dozen programmers. Hmmm. Less than 5% of switch() statements had a default: case for error-checking. Less than 20 uses of the assert() macro in the whole code base. And so on. The programmers mostly came from a Pascal-like environment so almost none were using C idioms like if( (p = fopen(...)) == NULL) for error checking. That is OK but I found dozens of cases where they were allocating memory, starting processes or opening files, sockets or pipes with no error checking at all.

about 8 months ago

Censorship Doesn't Just Stifle Speech — It Can Cause Disease To Spread

rover42 Religion & epidemics (70 comments)

There was a medieval cholera epidemic spread by multiple groups of religious pilgrims. It began with Hindu pilgrims bathing in the sacred Ganges at Varanasi & then going home; that spread it over most of northern India. Moslem pilgrims going West for the Hajj then spread it to Persia, Baghdad, Jerusalem, ... Finally, crusaders brought it to Europe. It killed tens or hundreds of thousands in all those places.

1 year,26 days

Looking Beyond Corn and Sugarcane For Cost-Effective Biofuels

rover42 Rubber plants? (242 comments)

In the 80s, I met a PhD biochemist who had worked on making synthetic rubber from petroleum products. He said going the other way -- from the latex in rubber tree sap to something that could substitute for gasoline -- looked feasible. All the science was known and in principle the process would be straightforward, but neither the engineering nor the economic/political problems involved had been solved. Is anyone looking at this sort of thing today? What about oil-producing plants, such as oil palms?

about a year ago

Real World Code Sucks

rover42 Once upon a time ... (292 comments)

I woked as a texg writer at a large company that I won't name. The group I was in developed test tools for internal use company use, nothing that got shipped to clients. They had 600,000-odd lines of C code in the tool set. One day I did some grepping through it. I cannot recall everything I checked, but all my results were awful. Things I do recall: A couple of thousand uses of functions that could fail like fopen() or malloc() without the idiom (fp = fopen(...)) != NULL or the same with ==. I checked a few manually, and none had any other error checks. Only about 5% of switch() statements had a default case. There were under 10 uses of the assert() macro in the whole set, all in one guy's code.

about a year and a half ago

Ask Slashdot: How Does an IT Generalist Get Back Into Programming?

rover42 Re:Stay in the IT Discipline....go DevOps (224 comments)

Yes. In particular, you mentioned doing various things related to databases. Consider learning more SQL and looking at DBA jobs. Those require most of the skills that progammers need, some of them pay quite well, and all the skills you already have would be useful fo a DBA.

about 2 years ago

Zero Errors? Spamhaus Flubs Causing Domain Deletions

rover42 Re:no sympathy (170 comments)

An anonymous user writes: " It's time to switch from mass-email to a web page with RSS. If people really want your newsletter, they'll come to you." That would be fine in many cases, but it does not work for the purpose in question here. For example, consider a user in some country where many web sites are censored, blocked by government filters. He or she can use a proxy, but the gov't routinely blocks proxy sites too. Even VPN hosts may be blocked. Benhett's group's role is to continuously create new proxies, let people know about them, and hope they can get some mileage from them before they are blocked. The notifications cannot be done via the web, for two reasons. One is that the web site involved would of course be blocked, so it would do users little good. The other is that it would give censors a list of proxy sites to block.

about 2 years ago

Linus Torvalds Will Answer Your Questions

rover42 Immutable files (460 comments)

I'm a bit of a conservative technically. No C++, just C, and if I need scripting I'll use the shell, sed(1), awk(1), etc. rather than learn Perl or PHP. I see the benefits of some of the more modern stuff; I just don't feel I need them. There are only two things added to Unix since Seventh Edition that I'm absolutely certain were improvements. One is TCP/IP networking. The other is the immutable files from 4.4 BSD. They seem to me to be a very simple and powerful security mechanism, one that would let me fairly straightforwardly secure much of a system. Much easier than working with SE-Linux in particular. My question of course is why the Linux kernel does not (yet?) support immutable files. Yes, I know about chattr(1), but it does not give BSD-style immutable files that even root cannot change.

about 2 years ago

Chip and Pin "Weakness" Exposed By Cambridge Researchers

rover42 Re:Presumed secure = blame the user (133 comments)

muhula writes: The scary part of this chip and pin vulnerability is that banks have a history of blaming the consumer and not issuing refunds ... banks systematically suppress information about known vulnerabilities, with the result that fraud victims continue to be denied refunds Ross Anderson heads the Cambridge group that found this attack and the earlier man-in-the-middle attack (a gadget between card & reader that makes all PIN verifications succeed no matter what number you enter). He's been writing about bank vulnerabilities for years. A famous older paper: "Why cryptosystems fail" Problems with PIN numbers:

about 2 years ago

Ask Slashdot: What's the Best Place To Relocate?

rover42 Phillipines? Malaysia? ...? (999 comments)

As someone said earlier, forget China (unless you can get a Western company to send you there at a Westen salary). Visa policies are fairly tight; there is no simple way to get a visa longer than one year. Ten-year vias are possible, but you need five years married to a Chinese, four years in a senior job in China, or starting your own successful company in China before you can even apply.

It is not a perfect fit for what you want, but check the Wikitravel article on "retiring abroad" for info on various places that are cheap to live and that do encourage immigration:

more than 2 years ago

On my summer vacation, I did / will do / am doing:

rover42 Several of the above? (240 comments)

I'm flying through 12 times zones with stops in four countries. Seems like fairly low-key travel to me as a long-term expatriate, but does that rate as "spectacular" on your scale? I carry a laptop and do some work during the the holiday, but it isn't particularly "drudgework".

more than 2 years ago

Ask Slashdot: Find a Job In China For Non-native Speaker?

rover42 Re:Jobs in China (402 comments)

I was a techncal writer at home. Here in China, I work in the Computer Science department of a university as an editor. Publishing papers in international journals is a degree requirement for graduate students here. Their English is generally good enough to write something mostly comprehensible, but usually below the standard a decent journal requires. Your best bet for similar work in Beijing would be the top technical university there, Tsinghua:

more than 2 years ago

Ask Slashdot: Find a Job In China For Non-native Speaker?

rover42 Jobs in China (402 comments)

Much the best of the many China expat forum websites is: There are an almost infinite number of English-teaching jobs in China, and any foreigner here will get offers to tutor people. However, many contracts forbid outside work; it is quite common to cheat on this and employers often overlook it, but you cannot count on that. For an overview of overseas English teaching in general, see: Getting one of the teaching certificates they discuss might help a lot if you want that sort of work. As someone said in another post, many of the best-paid teaching jobs are at schools that are joint ventures between a foreign and a Chinese institution. For jobs in IT, the best pay & conditions are at foreign companies. There is not a lot of demand for foreign developers and engineers, though there is some, but project managers are in great demand. In some cases, anyone who speaks English well enough to talk to the clients will be given the title "project manager"; in other cases they want real management skills.

more than 2 years ago



Ask Slashdot: tiny computer and projector?

rover42 rover42 writes  |  more than 2 years ago

rover42 (2606651) writes "I travel a lot, usually on a tight budget and often on airlines with tight luggage weight restrictions and high fees for going over, so travelling light is very important to me. So is connecting to the net when travelling, which creates a conflict. I do not trust machines in Internet cafes and my laptop adds significant weight & bulk to my luggage. I could buy a small netbook or a Macbook Air, but is there another choice?

There are quite a few tiny computers available, Rasberry Pi and the like. Alone, they don't solve my problem because you need a screen and that is at least as heavy as a laptop. However, there are also quite a few tiny projectors (e.g. see Would a tiny computer plus a tiny projector do the trick? Which ones? All I need for software is some open source Unix (any *BSD or LInux distro should be fine, or even Minix), a browser and an editor. I don't need large storage or a fast CPU.

Has anyone done something like this? Does anyone have a recommendation for either the computer or the projector?"

Chinese Internet firms "punished" for rumors

rover42 rover42 writes  |  more than 2 years ago

rover42 (2606651) writes "Major Chinese sites Sina and Webo "have been legally punished for permitting the spread of unfounded rumors. Specifically, the report cites unfounded rumors that were spreading like wildfire on Sina Weibo of an attempted coup d’etat happening in Beijing."

The source is the state-run Xinhua."

Link to Original Source


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