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Comment: Re:It's worse than just 0.5 GB of slow memory (Score 1) 159

by ChumpusRex2003 (#49105085) Attached to: Nvidia Faces Suit Over GTX970 Performance Claims
It has 7/8 of the processor. In traditional GPU designs, this would mean that only 7/8 of the RAM is addressable and that the RAM data bus is only 7/8 as wide - as parallel modules of both stream processor, L2 cache and memory controller get disabled.

The 1st 3.5 GB operates on the 7/8 wide bus (224 bits); this is the same as on any other reduced core count card. However, nvidia added a new "bypass" bus inside the GPU permit 2 memory controllers to be driven by a single L2 cache module. This avoids the need to reduced addressable RAM in the event of a L2 cache module being disabled. This last memory controller without a dedicated L2 cache module then accesses the top 0.5 GB of RAM via a 1/8 wide (32 bit) bus.

Comment: Re:A precaution when done ahead of time. (Score 1) 311

by ChumpusRex2003 (#49068587) Attached to: Nuclear Plant Taken Down In Anticipation of Snowstorm
The key point is to allow the reactor to cool for 24 hours or so in a maximally controlled environment - grid power, with backup diesel generators and full tanks for fuel. Once you're through the first 24 hours, the thermal load of decay heat is almost an order of magnitude lower, and much easier to handle.

It is also undesirable to expose the plant to grid transients. Short circuits on the grid, can cause severe mechanical disturbances to the alternator and turbomachinery. In a nuke plant, the LP turbines are typically very large, low speed machines with huge blades. These are susceptible to shock loadings due to their high moment of inertia. In fact, in nuke plant turbines, grid transients are one of the most important factors in determining fatigue life of the turbine assembly.

More over, there is a degree of thermo-hydraulic coupling between the turbine and reactor (or at least the steam generators) - these pressure and heat transients are also a contributor to fatigue life of the primary coolant circuit.

Comment: Re:A precaution when done ahead of time. (Score 1, Informative) 311

by ChumpusRex2003 (#49068511) Attached to: Nuclear Plant Taken Down In Anticipation of Snowstorm
That's not quite correct. There was no some damage to the emergency cooling systems, but it wasn't catastrophic.

At unit 1, the emergency isolation (condenser) cooling system (UPS powered) were manually turned off about 20-30 minutes after the earthquake, because they didn't want to "cold shock" the reactor, and switched instead to alternate methods of cooling (which required AC power). In the confusion that followed loss of AC power, they relied on staff to run outside and check the emergency cooling vents for steam. Staff were not familiar with the volume of steam which should flow from the isolation cooling system (should completely engulf the plant in thick cloud) and reported "faint steam" which was presumed to be due to operation of the isolation cooling system - but was, in fact, residual heat in the vent stacks, as they cooled following shutdown of the isolation condensers. Unit 1 likely suffered total core meltdown within 3-4 hours of the earthquake.

At plants 2 and 3, the emergency cooling system failed after the UPS systems powering the control systems depleted their batteries - a period of about 9 hours after the earthquake. Partial meltdown likely occurred within a few hours of core cooling loss. The extent of core damage is much lower than occurred in unit 1 because the first few hours are when decay heat is highest, and therefore severity of meltdown drops dramatically once through this period.

Fire pumps were brought in to inject water into the reactors at units 2 and 3. In this case, the water pooled in a tank and never reached the reactor. This was not due to a valve fault. The plan to inject water using fire pumps was an ad hoc plan, and the assumption was that the tank was connected to the injection line via a "positive displacement" pump (which would act as an obstruction to flow when unpowered), in fact, the pump was an impeller pump, through which the water could flow with ease. Even if this had worked, this was too late anyway, meltdown would have been near complete by the time the pumps were brought on site, and connections made.

The main lessons learned were: Don't turn off safety systems during an emergency Make sure staff are able to recognise the correct operation of safety systems Ensure that plans for the emergency provision of cooling water are pre-prepared, validated and well rehearsed. Ensure that emergency portable pumps are available near (but not too near) to site, and that their performance has been validated as acceptable Ensure adequate redundancy of hydrogen-oxygen catalytic recombiners Don't forget about the fuel pools.

Comment: Re:Not a fan (Score 1) 304

by ChumpusRex2003 (#48894223) Attached to: Government Recommends Cars With Smarter Brakes
You raise an interesting point that the interaction of various sensor assist systems can be erratic

In your example, your description cannot be technically correct, although I am not denying that it introduces a degree of instability that would not otherwise exist. Traction control does not, and cannot, apply the brakes. It also does not assume you are or are not in a spin, only that one wheel has lost grip. More advanced systems, e.g. ESC, do detect spin, but they do it with a yaw rate sensor, so it is directly measured, not assumed. The normal operation of traction control is to detect one of the drive wheels spinning faster than the other wheels, and when activated it reduces engine torque (through triggering fuel cut, ignition retard, and/or electronic throttle closure).

One of the things that OEMs found after integrating systems like traction control, stability control, ABS, etc. was that at the boundaries of slip/acceleration/yaw between the systems and normal operation, there were discontinuities in the vehicle dynamics. So, that if you were accelerating, and a drive wheel slipped, there would be a sudden, dramatic reduction in engine torque; or in the event of an impending spin, there would be a dramatic braking of the inside wheel, which could lead to an overcorrection.

Over the last 5 years, the OEMs have realised this, and they have been working very hard to smooth the discontinuities that these systems create. There are all sorts of marketing words for this, e.g. Toyota have "Vehicle dynamics integrated management". All this means is that the sensitivity and power of these systems has been carefully matched to the car and each other, to avoid sudden shocks.

Comment: Re:Anyone else concerned? (Score 1) 164

by ChumpusRex2003 (#48836115) Attached to: Man Saves Wife's Sight By 3D Printing Her Tumor
You have made my point (which admittedly I didn't make very clearly). What is useful is a knowledge of anatomy, and knowing what the potential problems are, and careful examination of the raw data of the CT scan. A skilled doctor would have specifically looked for the optic nerve in relation to the tumor. For whatever reason, this was not detected, or not communicated appropriately, resulting in a delayed treatment.

Complex 3D rendering or printing, while it looks impressive, generally isn't all that useful for making the diagnosis - the raw (or minimally processed) data tends to show the anatomical relations most clearly. The raw volumetric data shows everything; a 3D rendering depends upon some sort of thresholding, and the 3D projection necessarily results in occlusion and obscuration of objects. The thing about 3D rendering is that it is immediately recognisable by the lay person, or doctors without specific training in interpretation of CT, whereas the appearance of the anatomy is rather alien to most people when presented as cross-sectional raw data.

As for treating tumors, I'm afraid you're wrong about that. Watch and wait is very important for tumours around the eye and base of skull, because the anatomy here is so complex and fragile that the whole tumor may not be removable, or may be removable only at significant cost (loss of vision, facial disfigurement, risk of infections due to bone holes, etc.) For this reason, if a tumour is only causing minor symptoms, and there is good reason to suspect a benign tumor (i.e. not cancer liable to spread elsewhere in the body), there are often good reasons to delay surgery, until such time as the symptoms resulting from side effects of surgery are likely to be less than the symptoms from the tumor.

Comment: Re:Anyone else concerned? (Score 1) 164

by ChumpusRex2003 (#48813031) Attached to: Man Saves Wife's Sight By 3D Printing Her Tumor
3D visualisation is pretty standard on medical imaging software, but it's not really that useful for most situations. The issue here appears to have been the missed diagnosis of optic nerve compression by the tumor. As it is, a 3D rending/print of a CT scan won't help with that, as both the nerve and tumor will have similar appearances and very low background contrast to normal tissues. Where 3D rendering or printing of CT is useful is for examining the bone. It sounds like the 3D printing is an interesting factoid tacked onto a story about a misdiagnosis which was corrected after the patient/relatives asked for a 2nd opinion. This, of course, assumes that the diagnosis was wrong in the first place. "Watch and wait" is often far preferable to surgery for slow growing tumours in awkward places.

Comment: Nukes should already be hardened (Score 1) 39

Most national regulators require that any safety-critical computer systems in nuclear facilities are formally proven correct. Due to the difficulty in producing absolutely bug-free code, and proving that you have done so, a lot of systems continue to rely on pure analog control.

For example, nuclear-grade UPS systems typically offer a feature such as the following: "Digital logic free. 100% analog control with fully verified behavior. No need for expensive and time consuming software verification"

Similar validation is available for nuclear grade diesel generators and their control systems.

Similar design principles are often applied to the reactor instrumentation, although reactor control is usually digital and verified to the highest level. That typically means no inputs to the system, except the core sensors and core controls. The software uses only a minimal subset of language and OS features - e.g. no memory allocation, no dynamic linking or binding, etc. Calibration and model data must be built into code using a validated code generator and then statically linked into the binary, all memory must be statically allocated at compile time, etc.

The risk is whether less critical systems may be at risk - SCADA and similar systems may be in use for alternator controls, or in switchyard controls. The risk is that grid power to the plant could be interrupted, forcing the plant onto generator power. Or perhaps, other plant might be degraded - non-critical water pumps or plant controls, could mean that under degraded conditions, the plant has less tolerance to a reactor accident.

Realistically, unless you have schematics which detail the control systems in use, it is not possible to determine the severity of a particular attack. Further the interaction between different plant systems may be difficult to predict.

Even if the only realistic target for a cyber attack is the switchyard, that is still highly disruptive and degrades the safety margin of the plant by removing grid power as an energy source.

+ - Collection misconceptions: the air in the cabin is hazardous to health->

Submitted by Anonymous Coward
An anonymous reader writes "One of the components widespread among the people aerophobia — long-held belief that the air in the cabin liner, particularly heavily saturated with microbes and therefore catch a flight a breeze. At first glance it is. Inside, crowded, and the air inside the aircraft (especially when landing on it) seems a little stale."
Link to Original Source

+ - SPAM: Sim City 4 Cheats PC, Xbox 360,PS3

Submitted by Anonymous Coward
An anonymous reader writes "- The original Sim City 4 Cheats was very simple and by today’s standards, very primitive. The graphics were crude two dimensional blocks and the terrain itself was pretty unrealistic. But people had a blast playing it. As you kept building onto your city, which had to be done under certain basic rules, it became harder and harder to keep it from crumbling under your nose. There was a degree of realism to the game. As your city grew and the population grew with it, so did crime, pollution and all the other negative things that went along with Sim City 4 Cheats."
Link to Original Source

+ - Google Earth API Will Be Retired On December 12, 2015

Submitted by Anonymous Coward
An anonymous reader writes "Google today announced it plans to retire the Google Earth API on December 12, 2015. The reason is simple: Both Chrome and Firefox are removing support for Netscape Plugin Application Programming Interface (NPAPI) plugins due to security reasons, so the API’s death was inevitable. The timing makes sense. Last month, Google updated its plan for killing off NPAPI support in Chrome, saying that it would block all plugins by default in January and drop support completely in September. The company also revealed that the Google Earth plugin had dropped in usage from 9.1 percent of Chrome users in October 2013 to 0.1 percent in October 2014. Add dwindling cross-platform support (particularly on mobile devices), and we’re frankly surprised the announcement didn’t come sooner."

Comment: Re:What is critical thinking? (Score 4, Interesting) 553

by ChumpusRex2003 (#48223369) Attached to: Employers Worried About Critical Thinking Skills
Which is exactly why the "establishment" has been trying to ban it.

No, really! The Republican party had the opposition of "teaching of higher-order thinking skills, critical thinking skills and similar programs" in schools written in their platform document as one of their policy aims.

Wash post

Comment: Re:Computer Missues Act 1990 (Score 3, Insightful) 572

Why would FTDI have to ensure their driver doesn't break chips that aren't theirs? There's no agreement, licensing, or goodwill. The problem is that this was not accidental. The FTDI anti-clone code in the driver is very sophisticated and actually performs a "preimage" cryptographic attack, to ensure that the clone chip doesn't detect the invalid configuration and auto-reset to factory defaults. Deliberately and with premeditation setting out to "damage" (which in legal terms includes temporary malfunction or impaired function) hardware is not legal without a court order or similar legal basis. The 2nd issue, is that of ensuring that they do not inconvenience wholly innocent parties. They failed at this. The FTDI anti-clone code will also deactivate genuine FTDI chips which have been configured with an external configuration memory in certain circumstances. This has been reported by a company which build development boards with numerous FTDI chips in different configurations; they found that the chip with an external EEPROM would get corrupted by new driver, even though the components were obtained from an authorized distributor.

Comment: Re:"Reasonable" my ass (Score 3, Insightful) 700

by ChumpusRex2003 (#48208525) Attached to: FTDI Reportedly Bricking Devices Using Competitors' Chips.
However, a lot of manufacture is contracted out. If you're buying 10 or 20 chips for internal R&D you'll likely get genuine ones.

However, when you find a contract manufacturer and ask them to make 100,000. You require an XYZ, Inc. ABC123 chip and ask the manufacturing contractor to source it. Unbeknown to you, they obtain a counterfeit source. The chip is virtually identical externally, and functionally very similar, so that your product passes validation testing.

You as the device designer and seller may have no idea that you have fake chips on your device. Perhaps, your RMA rate is higher than you expected due to chip failures, or perhaps you are getting a lot of bug reports from the field which are not reproducible on your prototypes, but are on production devices.

This isn't the first time a USB->UART vendor has taken vigilante action against fakes. The vendor Prolific had major problems with low-quality, buggy and slow fake chips, causing major support headaches for customers and themselves. I believe they ended up discontinuing their main product and replacing it with an incompatible version, while poisoning the drivers so that they would BSOD/Kernel panic if they detected a fake chip.

What the world *really* needs is a good Automatic Bicycle Sharpener.