Please create an account to participate in the Slashdot moderation system


Forgot your password?
Polls on the front page of Slashdot? Is the world coming to an end?! Nope; read more about it. ×

Comment: Re:Yeah, but can you stop the NSA (Score 1) 49

by mcrbids (#49827883) Attached to: New SOHO Router Security Audit Uncovers Over 60 Flaws In 22 Models

Just to be fair "perfectly secure" is probably overstating things considerably. It would pass "no known exploits" pretty well, certainly "commercially viable".

The only "perfectly secure" computer is off, unplugged from the Internet, and encased in 50 feet of reinforced concrete. And even then, there *are* ways to exploit it using *ahem* brute force...

Comment: Re:Odd thoughts: (Score 1) 191

by BitZtream (#49827485) Attached to: Microsoft To Support SSH In Windows and Contribute To OpenSSH

BSD tools are pretty standardized yes.

UNIX tools are specific, its a certification.

GNU/Linux is a SysV bastarded child formed by merging a pretty great kernel with any number of half assed intentionally incompatible in subtle ways user land utilities.

Nothing about Linux is BSD or UNIX other than the feel. Windows is in fact more UNIX than Linux is, with its posix certified interop layer that Linux supports well, but is not certified.

A older version of OS X is UNIX and Posix certified.

Comment: QUIT! (Score 1) 554

Excuse me while I hijack this comment.

You should QUIT while you can. Start you own business while you are able to live with your parents, sleep in a car, eat beans and rice, etc.

If you wait until you have a spouse and kids, you are locked in. Your options become limited.

Also, LISTEN when you are told to start a retirement account NOW. Don't wait even a month.

If you are not the entrepreneurial type then get your attitude adjusted. You are part of a team and not just some cog. It's easy to think that but you'd be surprised at what happens when you stop thinking that and act like a team member. People start coming to you, relying on you, and you start getting promoted. Don't sit in your cubical and bitch and moan. If your environment that precludes that, then find another environment. You've already decided that you are not going to work for yourself so find the best people to work for.

Comment: Re:I hate Uber but... (Score 1) 225

Yea, managed by assholes like that ... Knowing how they already treat their employees/drivers ...

They didn't get top researchers, that got the idiots to stupid to realize how much your fucking yourself over by willingly going to work for Uber.

Are you really that stupid? You think leaving a stable Uni to go work for "the most punchable management shit weasels" is a smart plan? You think they'll follow through on all their promises and standard social contracts for these guys ... But otherwise will shit on all the rest of society world wide?

There's a VERY solid chance uber won't exist in a couple years when governments finally get tired of their bullshit and fine them into oblivion ... At which point your just fucked because everyone else in your field knows about the morons who jumped ship for a big paycheck at a really shitty company.

Comment: Re:What a shocker (Score 4, Informative) 54

by mc6809e (#49802169) Attached to: Land Art Park Significantly Reduces Jet Engine Noise Near Airport

Who would have thought having trees, shrubs and other natural barriers between an airport and the people would reduce noise levels?

It's as if clear cutting was found not to work.

Who thinks that? People that have never studied noise abatement and think their cleverness is enough to allow them to intuit the science.

Trees and shrubs do very little. A thorough study from the state of Virginia showed

No matter how the sites were examined, there was no measurable difference in road noise. All differences at the more distant measurement locations were due simply to the distance effect rather than to any additional mitigating effects of trees, whether measured by planting density, age, height, or average tree diameter.

Comment: Re:I hate fear mongering... (Score 2) 225

by BitZtream (#49794817) Attached to: Why Detecting Drones Is a Tough Gig

Let me drop a 2 pound drone on your head from just 10 feet above you.

IF you survive it is unlikely you'll make such ignorant statements ever again, and I'm not even talking about loading it up with ordinance or even simply flying into you at high speed.

It's is trivial for a 2 pound drone to kill you by accident, all it takes is the most minimal effort to do it intentionally.

Comment: Re:Tesla enables Edison to win the endgame? (Score 1) 588

by BitZtream (#49794177) Attached to: How Tesla Batteries Will Force Home Wiring To Go Low Voltage

No, it doesn't.

DC is in fact absolutely shitty for long hauls, and that is in fact why we use AC.

Power plants run alternators at specific RPMs intentionally to produce AC. There are no American hydro power generation stations using DC. That would be stupid. Every single one of them uses 3600 hertz multiphase output, one of those phases will give you 60hz AC.

The parasitic losses of DC over long distance is reason enough that it's not done, when you couple in the fact that it HAS TO BE AC in order to do any sort of reasonably efficient voltage conversion just seals the deal.

It's used in SHORT haul international interconnects when each side uses different frequencies for their grid OR when they don't want to stay phase synced.

DC is stupid for normal people for anything other than the last leg, like between your Wallwart and device.

There are three ways to cut down DC voltage: convert to AC and use a transformer, use PWM and large capacitor bank to smooth it back to DC... Or resistive and essentially turn the extra voltage into waste heat. All of those suck, the last most of all, but also the one that can handle large loads best.

There is one way to boost DC voltage. Convert it to AC, or at least half wave AC and use a transformer.

Comment: Re:Use High voltage DC stupid... (Score 2) 588

by BitZtream (#49792181) Attached to: How Tesla Batteries Will Force Home Wiring To Go Low Voltage

Heh I should have read your whole post before replying to the first line, but let me pick you apart in another one instead.

1. Most stuff just works on high voltage DC as discussed above. Most switching power supplies simply don't know or care about AC or DC and due to their efficiency switching power supplies are used in almost everything electronic.

Absolutely wrong. The first thing most power supplies do is step down from high voltage AC to something in the general range of whats needed on the highest output value. They step down with a transformer. That transformer only works with AC, if you put DC in it, you're just going to burn it up as it turns into a magnet carrying more current (because its not AC, so the there is no inductive resistance, so there is more current). Please don't give anyone advice on electricity. Ever.

2. It's easier (and more efficient) to use high voltage DC for charging the batteries. All you need is a rectifier to convert that 220 into about 250V DC and charge the batteries, which is about as simple and efficient as it comes.

... You do realize those batteries you're referring to are actually made up of a bunch of smaller batteries right? There is no single cell at 200v. You aren't charging one 200v batter, you're charging a handful of 12v batteries that you're just blissfully ignorant of.

3. It's easer (and more efficient) to make an inverter that uses high voltage DC as input. It's pretty easy to just flip the current one way then the other to get AC sufficient to run most induction motors and transformer powered devices.

You have absolutely no idea what you're talking about. The conversion from DC to AC is THE BIGGEST LOSS in the inverters you're referring to. The actual transformer itself is pretty damn efficient if designed properly. Dealing with high voltage DC is extremely dangerous. It ARCs over distances that AC won't. You can put 200v AC traces on a circuit board with little space between them. Do the same thing with the same DC voltage and the board is going to randomly arc all over itself.

4. It's more efficient to use higher voltage in terms of wire size because IxR losses are less for the same power transfer. Chances are the same wires you have now will be fine, but if you go to low voltage (say 13.8V like in your car) you are going to need bigger conductors to avoid the voltage drops over long high current runs. Use higher voltage and lower current, and stick with the wires you have.

The first part is true, larger wires are better for lower current loss. The rest of this is false. DC has different properties than AC. Insulators, wire spacing, and load will behave differently at 200v AC versus DC. You CAN NOT use the same wiring unless you want to burn the building down. Please don't ever tell people anything about electrical wiring, you're going to get someone killed.

The rest of your post is pretty much factually incorrect in everyway as well, but I'm tired of pointing out how little you seem to know about the subject. Again, please stop trying to tell people things like this, its fraking dangerous and people could die from this ignorance.

Comment: Re:Use High voltage DC stupid... (Score 1, Insightful) 588

by BitZtream (#49792041) Attached to: How Tesla Batteries Will Force Home Wiring To Go Low Voltage

We need to use HIGH voltage DC at about the same voltage as your house is now, forget about going "low voltage" DC.

No, we don't.

120v AC will kick you off of it if you touch exposed wires.

120v DC will cause you to clamp down if you grab onto a wire or device that electrocutes you, and worse still, it'll kill you at much lower voltages than AC.

On that alone, HVDC is stupid in the home.

Thats ignoring things like how circuit breakers and switches behave under DC verses AC.

AC has a ridiculous number of safety advantages that are not present in DC, which is why you RARELY see high voltage DC.

Couple in the resistive losses of DC and HVDC suddenly looks really stupid to anyone with a clue.

Never let someone who says it cannot be done interrupt the person who is doing it.