Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×

Comment Bunch of stuff... (Score 1) 395

Logically you do not charge electric vehicles at a "commercial vehicle charging station" but at any regularly used parking point via induction charging.

Or you can do both. Going to all/most-cars-are-electric with older battery technology requires multiplying the grid capacity by about a factor of six. Fast charge capability improves on that drastically - for several reasons I'll get to below - but it still involves trippling it or so. As long as you're building it out to feed cars, you might as well build it out selectively, to both good "gas station" sites and to likely sites for charging while parked.

With fast-charging batteries you can ALSO put some charging coils under major roadways to charge them as they drive. (You wouldn't have to electrify the WHOLE roadway, just chunks of it. And you can have the utility handshake with the car's electronics to collect for the power - or refuse to supply it if it's unwanted or payment won't be forthcoming.)

Not all parking spaces and roads are worth electrifying, and people also need service when traveling. So IMHO, with fast enough charging to make it practical, there will still be quite a demand for electrified "gas stations" to fast-charge those cars that didn't have enough opportunity to slow-charge.

Fast charging at home, though would be problematic: You'd have to drastically increase your service, and the infrastructure behind it. There are a LOT of homes, and in some cases a lot of distance to run bigger wires and a lot of transformers to upsize. Building out "filling stations" for fast charging, or doing that first, lets the utilities concentrate their investment. Fast charge at an electric "gas" station while waiting for your neighborhood's turn for upgrade (or just avoiding paying for one) makes considerable sense.

Fast charging enables a substantial mileage improvement, too, especially in stop-and-go traffic or on hilly terrain. It HAS to be very efficient (because any substantial losses would fry the battery). With it being both efficient and fast, you can use it for braking, even rapid braking, and scavenge most of the energy that would otherwise be lost as heat. Current vehicles can recapture a little of the braking energy - if you stop slowly. Fast-charge batteries can get MOST of it - and then recycle it for restarting, or just cruising against wind resistance and friction once you're off the mountain. ... mega battery factories are so financially risky at this time, real battery breakthroughs are coming down the line, that will change everything.

Maybe not so much: As TFA points out, THIS one is pretty much a cheap drop-in, and the resulting battery is so good that it makes the quantitative leap in to the practical. Lithium is really light. So this battery might be so close to optimum that it will be hard to make big enough additional breakthroughs to displace it if it takes market share now and does its own incremental improvements later. Meanwhile, the perfect is the enemy of the adequate. This looks good enough that it's time to adopt it. So "the future" might finally be here.

Not just used in cars of course but also to be used in residential properties to really drive renewable energy sources and people in the burbs being able to escape the grid ...

Right on! Raw generation with solar photovoltaic in sunny locations is already cheaper than grid power. Windmills in windy areas have beaten the pants off it for a long time and in moderaty windy areas has done the same since strong rare-earth magnets became available at reasonable prices. The control electronics participates in the Moore's Law effect and its price will drop even faster, due to economies of scale, if deployments become common. The big rub has alwayd been storage.

High efficiency, high capacity, high charge/discharge rate, many cycle, long calendar life batteries, made of inexpensive, common, non-toxic materials, built in high quantity under substantial price pressure for automotive applications, would fill in the last hole. Further, the capacity appropriate for a car is happens to be great for a house as well. They're a major game changer for yet another game.

Further, if lots of houses go to renewable, they'll have periods where the winds have been calm and/or the sky dark where there isn't enough energy available to charge the car AND avoid a blackout at the house. That's a good time to charge the car at the electric "gas" station. But for that to work the stations must exist.

Comment Leaving 5,000 doing something interesting. (Score 3, Insightful) 146

3.995 million of them are currently collecting dust in the desk drawers of neckbeards.

Leaving 5,000 of them doing something interesting and useful - and probably something that couldn't be done affordably with a brain that cost $800 or more.

If the computer costs just chump change, who CARES if most of them end up gathering dust? The cost of that is trivial, which the benefit of those that DO get used is substantial.

It's like pencil sharpeners (back before cheap automatic pencils): They spend almost all of their time idle. But they're so cheap that it makes more financial sense to have one in every office than to have one for the company and a department scheduling its time-sharing.

(That analogy was acutally used, to get executives to rent a clue, during the transition from central timesharing systems to ubiquitus desktop machines. When a computer costs several million and needs a clean room and dedicated hierarchy, it makes sense to have one and spend a lot of effort rationing it out. When one costs a thousand bucks it's far cheaper to put them on every desk and leave most of them horribly under-utilized. Such a price drop creates a qualitative change to resource allocation strategies.)

Comment I'm using BeagleBone Black. (Score 2) 146

I'm using BeagleBone Black. Not wedded to it - it was just handy. Any of several others would have worked, but this was available and had the right stuff available, too.

$55, half a gig of RAM, four gig of flash filesystem (plus a socket for adding more).

Runs Linux (and several other OSes with ARM support.). Comes stock with Agngstrom but I installed a port of Ubuntu 14.04 LTS and an upgrade to the corresponding kernel version. (The stock Ubuntu port to BBB uses an older kernel, but there's another project that ports later kernels as drop-in replacements.)

The kind of capabilities you are looking for are out there.

Comment Know your enemy. (Score 1) 187

Holy crap, I can hardly believe this topic. Who in their right mind would want FM opinion on anything? This is really puzzling to me.

There's a saying that applies: Know your enemy.

I doubt anyone will be fooled into thinking his arguments are unbiased, or correct, and adopt the mindset he's pushing. (If nothing else, there will be PLENTY of warnings from posters in the discussions. B-) ) So this is a chance to do a little research: Find out what arguments are being brought into court and congressional cloakrooms by those opposed to innovation and competition from outside of established corporate monoliths, so we can get ready with counter arguments.

Comment You don't need Florian to answer that. (Score 4, Insightful) 187

As an independent software developer, how can I avoid getting dragged into a patent lawsuit? How can I leverage my rights to ensure others aren't exploiting my patents?

You can't.

A patent is just a license to sue.

It licenses others to sue you if they think you might be infringing their stuff (or they can get you to pay them to go away even if you aren't). It licenses you to sue others who are infringing your patents. That's all it is.

If you want protection for your creations, you have to be ready to put on the armor and walk into the arena to defend them.

Comment Re:Actually, it's easy. (Score 1) 174

I'm pretty sure that Battlefield is a UDP not TCP protocol so does UDP have the 'intelligence' to discard duplicate packets?

No it doesn't. UDP is just minimalist port-number-multiplexed, checksummed, access to the underlying IP protocol. It delivers the packets as they arrive, with no sorting out at all. (The underlying IP layer handles fragmentation and reassembly, but that's about it.)

That is why the SERVER and CLIENT that USE UDP have to, themselves, handle the dropping, reordering, and duplication of packets.

Comment Re:Actually, it's easy. (Score 1) 174

Data structure might be...

Of course, with only two links, you only have to track the packets that have come in on one link but not yet on the other. That makes it even easler.

Similarly, but not quite as simply, with more than two links, with situations where you throw things down some but not all of them, etc.

Comment Actually, it's easy. (Score 2) 174

This isn't possible, nor should it be.

Actually, it's almost trivial.

I don't know if there's something already available and free, so here's how I'd build it.

It'd startt with OpenVPN. (Mosly because it's the only hackable VPN I'm familiar with that's currently supported.)

I'd first take advantage of the fact that servers and clients are SUPPOSED to be able to handle duplicated and reordered packets and do it the simple way: Just hack it to throw each packet down both pipes, and at the receiving end just forward both copies.

Then, if the server and/or the client DON'T handle the duplication gracefully, I'd add sequence numbering to the VPN wrapping (if it isn't there already) and a mechanism at the receiving end to keep a small amount of history of what has gone out and drop the slower copy (if it arrives before the history of its other copy has timed out).

Data structure might be a small tree or heap of ranges-of-packets-that-have-left (pruned to drop older stuff when getting too nodefull or near sequence-number-wrap-around due to good packet weather), or maybe a rotation of three hash tables - "now", "recent", and "being cleared / cleared and waiting for rotation" - with the first two in use.

Comment I have no problem at all imagining that. (Score 4, Informative) 174

I find it hard to imagine that it would (at least routinely) be faster than using his current wireless setup to route his traffic from his desktop ... through his cable modem ... through his ISP ... through a remote datacenter (somewhere) ... to the Battlefield servers

I have no problem at all believing that. The OP says he is using two MOBILE access devices from two (wireless) carriers and is (if I read him right) experiencing substantial intermittent (but separate) delay and/or drop events in both of them. If he throws each packet down both of them and the first one to arrive at the data center gets to the game server, the packets that are lost or delayed on BOTH paths will be very much rarer and his gaming experience will be substantially improved.

Yes, he'll get a little extra latency on the fast packets - which is most of them. But server farms generally have fat and blazingly fast backbone connections, so it shouldn't be a lot added. A small price to pay to make almost ALL packets arrive reasonably quickly and almost NONE experience big delays or loss.

Comment Re:What makes you think (Score 4, Informative) 174

Doesn't TCP require it come back on the path too?

Absolutely not. Nor does it expect that to usually happen. The routes in opposite directions are often different. (For starters, they're based on the local knowledge of the routers at opposite ends of the path, which are typically familiar with their neighborhood and may have no clue about what things are like near the other end.)

The routes of diffetrent packets in the same direction are often different, too (like for load-balancing by throwing alternate packets down two slower links to get an effectively faster link). Every packet is potentially routed differently (though routing protocols like label switchingmay often set up connection-like shortcuts that make consecitve packets take the same path - to speed things up).

What matters is just that they get to the same ENDPOINT. Some may be silently lost. Some may be duplicated. Some may arrive out of order (like when a route changes and later packets get there faster).

It's been like this since IP, UDP, and TCP were invented. It was a core principle of their invention.

= = = =

Having said that:

Deviation (other than packet drops) from simple first-in-first-out packet flow tend to be rare. So not all servers and/or clients handle them well. (TCP will sort out missing and misordered packets on the receiving end - sometimes at substantial cost in buffering and latency. UDP will not - for simplicity, speed, and for when occasional lost packets are less of a problem than high latency and occasional long delays. So if the server and/or client can't handle transmission problems well, performance may suffer or functionality simply fail.)

Many networking company customers of high-speed router makers make the additional requirement that a stream of packets coming in one particluar interface from one particular source and going out another particular interface to a particular destination are not reordered. That's a pain when the router's guts are a sea of little processors each handling packets individually, so additional special purpose hardware may be added to track packet order and insure things don't get reordered between input and output queues.

Comment Re:Only in Africa? (Score 1) 478

The situation in the American South is totally different though, right?

Nice rhetorical scoring, but, yes, it *is* totally different. Comparing the poverty, lack of trust in government workers and dysfunctional healthcare system in the US South to those factors in Africa is like comparing the neighborhood pool to Lake Erie.

How about the situation at the US southern border for illegal immigrants?

The US takes them into custody. It puts them in crowded rooms - standing room only - for hours to days, with lots of others recently apprehended or who turned themselves in, and inadequate sanitary facilities (and inadequate instruction for those who don't know how to use the ones that ARE there). That looks to me like an ideal way to insure that if ONE of them has Ebola, dozens or hundreds will be exposed.

Then, after carefully NOT taking any information like fingerprints (which might be used to identify and collect them later), it busses them (in crowded vehicles) all over the country and resettles them - typically with alleged "family" who often living in crowded conditions and with incentives to avoid authorities - especially any that come looking for them.

Comment He didn't deny them in the hospital. (Score 4, Informative) 478

[Hospital sent home the ebola patient in Dallas, though he had classic ebola symptoms and had traveled to Liberia.]

Yep, especially when they deny all of the screening questions.. That's helpful.

He denied the screening questions at the airport. ('Let's see. If I answer yes you won't let me fly and will throw me in with everybody else who answered yes. Of COURSE I didn't have contact with Ebola!)

He DIDN'T deny the questions at the hospital. They knew he'd been to Liberia recently. But their bureaucracy didn't get that info to the person who made the release decision.

Comment That needs another caveat: (Score 1) 144

an educated population is one of the best defenses against mindless wars. That's why it's so important to the corrupt governments that want to wage those wars to have control of the education systems in their societies.

Because MISeducating their population is key. "Give them a light, and they'll follow it anywhere."

But this needs another caveat: If the population in general doesn't have any effective power over the goverenment, they can know exactly what's going on, be against it, but be utterly unable to change it. If some of them attempt to make such change, it just separates them out from those who will knuckle under, for easy removal from the herd.

Comment How about polywell? (Score 1) 315

This article led me to check what was up with the Navy's work on the Polywell concept, long kept under their hats. I discovered:

The navy just published their results last Sunday!

I haven't time to look into it for the next few hours, but this may be very interesting news on the "are we there yet?" front.

Comment Re:The $50,000 question... more energy out than in (Score 1) 315

No. Current solar absorption (accounting for albedo) is on the order of 50PW. By comparison, current peak world wide energy production is a paltry few TW. We're several orders of magnitude away from the point where our civilization's thermal output becomes a concern.

Not to mention that we woudl stop putting carbon dioxide from energy production into the atmosphere (and could, if it became an issue, use some of that fusion power to freeze some of it OUT of the atmosphere and do things like turn it back into coal and bury it.)

If human industry generated CO2's contribution to the greenhouse effect IS significant, we could pull that "gift that keeps on giving captured solar heat" back out of the air and put it into the bottle - at least until we reach pre-industrial levels. (Beyond that we probably don't want to go, because of the detrimental effect of low CO2 levels on plants.)

Slashdot Top Deals

If Machiavelli were a hacker, he'd have worked for the CSSG. -- Phil Lapsley

Working...