Please create an account to participate in the Slashdot moderation system


Forgot your password?

Comment: Re:Not a fan (Score 1) 285

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.

Comment: Re:The good news (Score 5, Informative) 700

by ChumpusRex2003 (#48208359) Attached to: FTDI Reportedly Bricking Devices Using Competitors' Chips.
Yes. A company called Supereal is selling enormous volumes of "FTDI" chips into the Chinese market. The chips are labelled with the FTDI name and logo and during the USB negotiation, they announce themselves using the FTDI vendor unique ID, in order to use the ubiquitous and flexible FTDI driver (rather than require any development work for their own driver).

See for an example of a fake chip - labelled FTDI on the outside, but supereal on the silicon.

The problem is that the fake chips are buggy and slow compared to the genuine article, causing headaches for USB peripheral designers and support and reputation headaches for FTDI. There is a huge market for USB UART chips, and it is quite competitive, but few of the products on the market are actually as reliable, fast and robust as you would expect them to be. The FTDI FT232RL is one of the best in terms of reliability and has the best drivers, while also providing some handy bonus functionality.

It appears that FTDI have reverse engineered the fake chips and found that they can be reprogrammed. When their driver detects a fake chip, it uses the internal configuration commands to erase the EEPROM memory containing the Vendor Unique ID. With this EEPROM blanked, the chip is unable to complete the device detection process in the OS's USB stack.

Comment: Re:no? (Score 4, Informative) 38

by ChumpusRex2003 (#48064205) Attached to: Snowflake-Shaped Networks Are Easiest To Mend
The aim was not to find the "best network", but the "best network without redundancy".

The point was that most networks are designed with redundancy in mind, but not all networks require that degree of reliability. For those networks where reliability is not necessary, it would be helpful to know what the lowest cost configurations are.

Comment: Re:Oh good (Score 1) 907

by ChumpusRex2003 (#47998799) Attached to: Miss a Payment? Your Car Stops Running
one or both of them are full of something. Not necessarily. They could both be right. The interlock device only defeats the starter. However, if the car lessee is defaulting on lease payments, then it is likely that they are also cutting back on scheduled maintenance and repairs. It is entirely possible that the engine is unreliable and idles poorly, being prone to stall when idling. It is perfectly possible in such a case, for a driver to reach an intersection, have the engine stall, and then be unable to restart it because the interlock has defeated the starter.

"The trouble with doing something right the first time is that nobody appreciates how difficult it was." -- Walt West