Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror

Comment: Because money and the inherent problems with AC. (Score 2) 516

by fishnuts (#48468617) Attached to: Ask Slashdot: Why Is the Power Grid So Crummy In So Many Places?

It costs money to upgrade and stabilize the power grid. It costs money to stay ahead of the failure curve.

The current infrastructure sucks mainly because it's unpredictable and takes too much effort to synchronize disconnected sections of the grid before connecting them. You can't just "route around" a dead transmission line if there are generator stations active on both sides of the break. You must wait for the two sides to synchronize in phase before connecting them, which can take several seconds to a minute. If you don't, you'll cause even more breakers to trip.

None of this would matter if we switched distribution to HVDC. We have the technology, but again, the cost to convert everything to employ DC-DC switching converters is prohibitive. The biggest upside to switching everything to DC (all the way to the end-user) is that you could add standby capacity by simply connecting batteries to your mains circuit between the main breaker and load panel. The more people in a neighborhood using batteries to buffer their power source, more aggregate protection the neighborhood has against blackouts.

Comment: All of these concerns would be moot with DC. (Score 1) 579

by fishnuts (#45798399) Attached to: Utilities Fight Back Against Solar Energy

(Note, this is more of a stream of consciousness than an actual comment, so I apologize in advance if this sounds ADD-ish)

Get rid of the bulky, loud transformers and phase shifting coils and cap banks. Run -12KVDC to -20KVDC over the residential feeder lines down to neighborhood-located equipment with switchmode buck converters to give -240VDC and -120VDC to homes via their usual 3 mains wires, and a fourth wire for homes who wish to feed power back into the local grid via switchmode boost converters. The power transformer boxes on the corner of every block will contain high-frequency switching equipment and a few batteries (for keeping the block lit during upstream switching events and outages) instead of 2000-pounds of copper and laminated steel. The neighborhood substations will have their giant transformers and oil-filled breakers and phase compensating equipment replaced with IGBT-based switch stacks and intelligent converters that quickly compensate for changing load and back-feed conditions completely silently. Managing connections between substations and the high voltage grid will be an order of magnitude simpler and safer when all you have to worry about is matching the voltages within a few percent and measuring static currents after connections are made, rather than comparing frequency, phase angles, and power factors. With today's "modern" AC grids, you're liable to blow fuses/breakers/transformers if you connect two independently-fed parts of the grid together without first matching phases and frequency.

I know it's just too late for the change from AC to DC in the home to be practical. The biggest, most power-hungry devices just don't have an "upgrade path" to DC: Air conditioning and refrigeration compressors, fan/blower motors, fluorescent lights would all need complete replacement with DC-compatible equivalents. It would have been better if appliance manufacturers had designed their devices to be run off either types of mains from the start... Large, high-torque brushless DC motors are quite cheap now, and switchmode power supplies are now smaller and cheaper than 60HZ AC power transformers, and many of them will actually work equally well being fed by 120-240VDC.

Comment: Transfer switches, batteries, and inverters, oh my (Score 1) 579

by fishnuts (#45791879) Attached to: Utilities Fight Back Against Solar Energy

Automatic transfer switches eliminate any danger of locally generated power being fed back into the grid if there's any sort of danger in connecting the two. The electric company would only have to tell home owners to employ transfer switches in order to stay connected to the grid (with the only side effect being that they can't contribute excess power back to the grid)

My local utility company actually employs smart meters that can monitor both grid-side and home-side circuits for dangerous conditions in cases where there's a grid-tie inverter in the home. The smart meter instantly disconnects the home from the grid if there's an excessive surge in current being fed back into the grid (by analyzing the voltages, transfer current, and phase angles of both sides). The same meters also communicate with the utility company over a combination RF and powerline-based data transmissions, eliminating the need for guys to be dispatched monthly to read everyones meters.

In other news, you can buy a good charge controller, a 50KWh bank of deep-cycle batteries, a 2KW inverter for lights and outlets, and a 12-KW inverter for air conditioning, all for about $12K. This setup can run A/C for 5 hours a day and your only reliance on the grid would be to top-off the batteries on dark days.

If you have the means to get off the grid, by all means, you should, because most electric companies don't care about anything but profits.

Comment: Does DJB insist that the library ... (Score 3, Insightful) 140

Does DJB insist that his crypto library gets installed under /var/lib? He's always insisted that his qmail binaries get installed under /var/qmail, and had everyone I know in the unix admin/engineering field shaking their heads, knowing that having executables and libraries on the /var filesystem is retarded and dangerous.

Comment: Re:damn philanthropists (Score 4, Insightful) 406

by fishnuts (#45256505) Attached to: A Look at the Koch Brothers Dark-Money Network

Regarding your statement, "But this is typical of the Progressives, they don't mind when it is THEIR guy mucking up the politics."

It's typical of _everyone_ in politics, _everyone_ in the media, and _everyone_ with an agenda. Don't blame just one party when _everyone_ is doing it. It's human nature to deny the guilt of yourself and the people you associate with when the goal is to discredit or disarm a group with opposing views.

Comment: At what scope of time or size of output data? (Score 4, Insightful) 240

by fishnuts (#45128427) Attached to: Linux RNG May Be Insecure After All

At what scope/scale of time or range of values does it really matter if a PRNG is robust?
A PRNG seeded by a computer's interrupt count, process activity, and sampled I/O traffic (such as audio input, fan speed sensors, keyboard/mouse input, which I believe is a common seeding method) is determined to be sufficiently robust if only polled once a second, or for only 8 bits of resolution, exactly how much less robust does it get if you poll the PRNG say, 1 million times per second, or in a tight loop? Does it get more or less robust when the PRNG is asked for a larger or smaller bit field?

Unless I'm mistaken, the point is moot when the only cost of having a sufficiently robust PRNG is to wait for more entropy to be provided by its seeds or to use a larger modulus for its output, both rather trivial in the practical world of computing.

Comment: Re: Shoot first (Score 0) 871

by fishnuts (#45063335) Attached to: Bennett Haselton's Response To That "Don't Talk to Cops" Video

Spoken like a true Libertarian. I'm surprised you didn't pull "authoritarian", "fascist", or "statist" out of your hat.

Society prospers when individuals work towards the prosperity of the societal unit, as well as their own being. When you stop caring about the greater good, what good are you to your country?

Would you rather just be an isolationist and give the rest of the world the finger?

Comment: Re:How close to 100% is the Windows 7 percentage? (Score 4, Insightful) 246

by fishnuts (#44845285) Attached to: Majority of Enterprise Customers Finally 'Migrating Away From Windows XP'

As an IT manager who oversees deployment and maintenance of about 60 desktops and laptops, some of which are shared among multiple employees, consistency in OS availability for the end user is key. We upgrade one or two machines per month, and we started using Windows 7 three years ago, so about 15 systems still run XP. We're not touching 8.1 until there are no more XP systems on our network, AND people show interest in actually using 8.1, AND at least one service pack has been released to address outstanding issues since its public release, AND we discover a way to disable the "Tiles" start screen. Supporting systems with two different desktop interfaces is a serious pain in the ass, especially for non-technical users. So far, only two people have shown interest in using Windows 8 (techie geek types), and the vast majority of our employees are averse to changing their OS at all.

I've had to customize Windows 7 a bit to make it "comfortable" for the lowest common denominator: Long-time XP/2000 users.

Data Storage

ZFS Hits an Important Milestone, Version 0.6.1 Released 99

Posted by samzenpus
from the brand-new dept.
sfcrazy writes "ZFS on Linux has reached what Brian Behlendorf calls an important milestone with the official 0.6.1 release. Version 0.6.1 not only brings the usual bug fixes but also introduces a new property called 'snapdev.' Brian explains, 'The snapdev property was introduced to control the visibility of zvol snapshot devices and may be set to either visible or hidden. When set to hidden, which is the default, zvol snapshot devices will not be created under /dev/. To gain access to these devices the property must be set to visible. This behavior is analogous to the existing snapdir property.'"

Comment: Does this mean we could possibly have CONTROL? (Score 3, Interesting) 99

by fishnuts (#41964321) Attached to: The Shumway Open SWF Runtime Project

Does this mean developers might actually implement 'MUTE', 'FORCE STOP', or 'RESTART' context menu items for shockwave apps? I despise going to read a page with ads and other shockwave sidebar widgets that make noise or chew up CPU cycles and have no way to pause/mute/stop them. It also bugs that you must reload the entire page to get a flash app to restart.

It's beyond me why Macromedia/Adobe never wanted us to have those essential controls. The only thing we get, in some rare cases, are the ability to prevent the app/player from looping, or to turn down rendering quality.

Hardware

+ - Why Can't Industry Design an Affordable Hearing Aid? 1

Submitted by
Hugh Pickens writes
Hugh Pickens writes writes "Tricia Romano writes in the NY Times that over the last 10 years, purchasing a hearing aid had become even more difficult and confusing than buying a new car — and almost as expensive. "I visited Hearx, the national chain where I had bought my previous aids. There, a fastidious young man spread out a brochure for my preferred brand, Siemens, and showed me three models. The cheapest, a Siemens Motion 300, started at $1,600. The top-of-the-line model was more than $2,000 — for one ear. I gasped." A hearing aid is basically just a microphone and amplifier in your ear so it isn’t clear why it costs thousands of dollars while other electronic equipment like cellphones, computers and televisions have gotten cheaper. Russ Apfel, an engineer who designed a technology now found in all hearing aids, says there is no good reason for the high prices. “The hearing aid industry uses every new thing, like digital or a new algorithm, to raise prices,” says Apfel. “The semiconductor industry traditionally reduces the cost of products by 10 to 15 percent a year,” he said, but “hearing aids go up 8 percent a year annually” and have for the last 20 years."

Comment: "widescreen" letterboxing/stretching (Score 1) 839

by fishnuts (#38270994) Attached to: TV Isn't Broken, So Why Fix It?

I think that until _all_ TVs have 16:9 screens and _all_ studios broadcast unmodified/uncropped/un-letterboxed content, we'll have the following two problems:

The disparity in video formats and whether they "letterbox" a high-def program for standard-definition channels is frustrating. Most modern studios and news stations in the US are recording in HD, then either letterboxing it for SD broadcast (adding black bars on top and bottom to make it 4:3 aspect ratio), or cropping the left and right side of the image to get the 4:3 image. The former is horrible for people with HD sets that can't overscan (scale up the side of the image so it fills the screen, eliminating the black bars) and you lose effective image resolution... I wish someone would drill it into their heads that letterboxing HD content is BAD for SD broadcasts. Your camera crew should try to capture actors and action within the central 4:3 area of the image so you can crop and scale your HD content for people with SD TVs or receiving SD channels.

Even more frustrating is when I go to a public place with widescreen TVs showing standard-def channels (in 4:3 format), S-T-R-E-T-C-H-E-D to 16:9, so everyone looks fat and square-shaped graphics become rectangles. Half the widescreen "HD" TVs sold now are able to overscan properly, and the other half can't at all (they just stretch the image). A few good brands can do a "panorama" transform, which is a compromise, but makes diagonal lines look curved. There really is no legitimate reason for a TV to stretch a broadcast image horizontally, yet everyone thinks they NEED to do it to "fill" their wide screens with a 4:3 SD image. It boggles me that so many people purposely distort the image just so it can appear "widescreen".

Sigmund Freud is alleged to have said that in the last analysis the entire field of psychology may reduce to biological electrochemistry.

Working...