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2 Galileo Satellites Launched To Wrong Orbit

ChumpusRex2003 Re:Interesting difference between GPS and Galileo (139 comments)

The SAR component of galileo is a separate service to the positioning service. The intention is that it can operate as an EPIRB receiver. Conventional emergency beacons can be located by satellites, but the resolution is poor (tens of miles) and the time to fix is long (30-60 minutes). The beacon transmits a signal, and suitably equipped satellites detect the beacon, and relay it to ground stations, which then compute the location of the beacon by measuring the change in Doppler shift as the satellite flies by. The SAR component of galileo was designed with the intention that the overhead satellites would detect the time-of-arrival of the beacon signal and cross reference it with the satellites' atomic clocks, effectively performing a reverse GPS-fix. Such a system would be able to obtain a fix within minutes or seconds, and such a fix would likely have a resolution of 1-2 miles. The SAR component is not a mandatory service. You can use the passive location service without implementing SAR in a device. You would only use the SAR service, in an emergency locator beacon device. At the time the galileo SAR system was designed, feedback was a problem with locator beacons. The user had no idea if the signal had been received. Later revisions to the system mean that modern beacons and satellites now offer two big upgrades - the beacons can contain a passive GPS reciever, and can embed the location data in the beacon signal; and the satellite system can transmit feedback to a compatible receiver telling it that it's signal has been received and a position fix made. The Galileo SAR function is therefore rather redundant, but it's often helpful to have a 2nd independent and redundant safety system available, so I can see that it would still get used.

4 days ago
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Network Hijacker Steals $83,000 In Bitcoin

ChumpusRex2003 Re:Where is the validation? (101 comments)

The mining hardware/software will report a realtime hash rate, based upon the operation of the hardware/software.

However, the process of mining is a stochastic random process. Essentially, the job of a miner is to find a partial "hash collision" - essentially, the miner hashes the transaction data and a random nonce, and aims to find a hash as close to 000000000....00 as possible. The bitcoin/alternative network agrees a priori, what threshold counts as a "hit". The miner essentially tries random nonces, until it either gets a hit, or is told that its transaction data is stale, and needs to be refreshed.

Because, in the case of bitcoin, the network sets the target such that on average 1 "hit" is found every 10 minutes worldwide. This means that an individual miner might have to run for weeks or months to get a win and be awarded the (currently) 25 BTC reward for successfully computing a hash below target. In practice, therefore most miners operate on "pools", where a central server coordinates multiple diverse pieces of mining hardware operated by multiple individual operators. The pool operator when they receive a 25 BTC reward, then divides it up amongst the contributors.

The way the individual pool servers account for hash rate is to set a lower hash target, and count the number of "hits" each miner gets. E.g. if the main bitcoin network has target is Because pools can only detect hashrate by the rate at which "hits" are delivered, the reported hashrate will necessarily vary by virtue of the statistical properties of a stochastic process. The degree of variation depends upon the "difficulty" (target) set by the pool operator, the degree of "smoothing" that the pool operator applies to the displayed statistics, your hash contribution (a bigger contributor, will have a smaller coefficient of variation in their displayed hashrate, again for statistical reasons) etc.

Things are further complicated because many of the affected pools are "multi-coin" pools. The pool server automatically scans multiple cryptocoin networks, and various cryptocoin exchanges, to work out which coin is most profitable, the server will then jump between coins every few seconds or minutes as needed. For various technical reasons, different coins have different "stale" and "orphan" rates - "hits" which should have resulted in new coin creation, but where the hit was rejected (either immediately - stale) or initially accepted, then rolledback (orphan). Some of the alternative coins had rather dubious technical designs which could lead to massive reject rates, and this too could result in displayed hash rates fluctuating like mad.

The final issue is that many pools were often run by rank amateurs, and were targets for hackers/DDos like red-rags are to a bull. DDoSes, random server crashes, bandwidth exceeds, etc. were all common place, as well as various software bugs in "multi-pool" backend software would cause miners to end up disconnected from servers. Smarter miners would have typically have several pools configured on their mining hardware, so that the software could fail-over to another server. However, even that wasn't always successful. I once left my mining hardware unattended for a week, and configured it with 8 pools. When I checked the logs when I got back, there was a period of about 24 hours when the mines were idle, as all servers were off line.

about three weeks ago
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TEPCO: Nearly All Nuclear Fuel Melted At Fukushima No. 3 Reactor

ChumpusRex2003 Communications and knowledge were a problem (255 comments)

This is the crux of the problem. No one knew what was going on and what to do. Investigations over the last few years have shown that typical TEPCO safety drills were very limited and basic; there was little planning or rehearsal of complex accident scenarios, just basic minor incidents.

There were poor decisions and communication between various designers and operators. Take for example, the situation at reactor 1. After the generators started, the emergency reactor cooling condensers should have switched on to provide cooling. However, operators had found that they were very effective and being unfamiliar with their use were concerned that they would cause thermal shock to the reactor. Not familiar with the operation of this system, the operators decided to manually switch off the condenser system to arrest the temperature drop. They would then switch them on again manually as reactor temp rose again. This worked fine, until the generators failed, removing control and monitoring from this system.

Operators at emergency control, in a separate quake-proof building asked for confirmation of operation, but the control room could not give it. So,workers went out to inspect the reactor building for steam rising from the condenser stacks. They reported some steam rising, and it was assumed that the system was operational. However, the condenser system had never been used or tested since the plants were constructed 40 years ago. No one knew how they worked and how quickly they could cool the reactor, no one knew how much steam was produced during operation. It turns out that the workers sent out for reconnaissance saw only faint steam trickling from the stacks, consistent with the system having been switched off for many minutes, but still containing some residual heat. Had the system been switched on, the clouds of steam would have been so profuse and so dense that the it would have been impossible even to see the reactor building, let alone identify the condenser stacks.

On the assumption that the system was operational, other attempts to provide emergency cooling were suspended or delayed. A steam/battery powered pump system was available to deliver fresh water to the reactor, but without a heatsink (condenser) available, the reactor temperature rapidly rose and so did reactor pressure, eventually overcoming the maximum discharge pressure of the coolant injection system. After a few hours, the UPS controlling this system discharged and it also failed.

After 24 hours, reactor pressure unexpectedly dropped. Operators realised that this might permit external coolant injection and fire engines were called in. There was a huge delay, as the fire engines were unable to reach the site due to debris and some had been destroyed by the tsunami. Subsequent investigation showed that despite massive coolant injection, coolant did not rise in the reactor. The cause was thought to be due to damage to the reactor vessel or a pipe. In retrospect, it probably indicated damage to the reactor following meltdown of the fuel.

There were also design oversights in the emergency systems for the plants. One of the final backup schemes for reactor cooling was the ability to connect fire engines to the reactor to inject coolant. It subsequently became apparent that in units 2 and 3, this water didn't reach the reactor, and collected in a condenser unit instead. This was always going to happen, due to the way in which the water pipes were connected. There was a pump connected between the storage tank and the injection flow pipe. Under normal injection conditions, the pump would have been running, and any additional water from the fire engine would likely have gone towards the reactor, and this presumably was the assumption under which the water injection protocol was developed. However, under power failure conditions, the pump was unpowered. Due to the design of the pump - a rotodynamic (impeller) pump. this pump would have offered little or no resistance to reverse flow when unpowered.

about three weeks ago
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UK Computing Student Jailed After Failing To Hand Over Crypto Keys

ChumpusRex2003 Re:Seems appropriate (353 comments)

This would not help. The exact offence is "failing to make readable encrypted data". In order to convict, the prosecution only have to prove that the data is encrypted, that you had control over that encryption and that they have not been able to read it. Loss of damage of the encryption keys is not a defence. The law was specifically designed this way in order to discourage self-destructing encryption keys, etc. The only defence against such a prosecution is to keep a backup of the encryption keys available, so that they can be handed over on request.

about a month and a half ago
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Qualcomm Takes Down 100+ GitHub Repositories With DMCA Notice

ChumpusRex2003 Re:Counter-notice! (349 comments)

Once the ISP receives a "put back" notice, they must pass to the original complainant in a timely manner.

The ISP must then wait for 10 days, to give the original complainant time to consider the "put back" notice, and decide whether a court case should commence. After the 10 day waiting period, if the ISP has not received notice of a restraining order blocking the put back because of an impending court hearing, then it is allowed to restore the content.

In order to avoid liability to their customer, the content must be restored with 14 days of receiving the "put back" notice, provided that the complainant has not obtained a restraining order blocking the put back.

about 2 months ago
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EU's Online Shoppers Get an Extended "Cooling Off Period"

ChumpusRex2003 Re:Wait what? (140 comments)

The change to digital data is welcome.

At least in the UK's interpretation of this EC directive (the Distance Selling Regulations), digital downloads were NOT excluded. The purchase could cancel the purchase at any time up to 7 days after purchase and receive a full refund. Technically, you could download a software package or a movie, and then change your mind and claim a full refund.

While the Distance Selling Regulations specifically excluded copyright material such as computer software, movies, music, etc. - they do so only in physical form i.e. CDs, DVDs, etc. Downloads are treated as a "contract for a service" which do not fall in the scope of this very limited exclusion.

The ambiguity over digital downloads has caused a lot of heartache for a couple of small software developers that I know - albeit not enough to try to take it to court. I'm not sure that there is any caselaw actually addressing this loophole in the current system.

about 2 months ago
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Did the Ignition Key Just Die?

ChumpusRex2003 Re:I don't like the control it takes away from you (865 comments)

That's correct, but the same system also has lots of other complex behaviours which could cause confusion.

How do you turn the car off but leave the radio on for the passenger - e.g. at a gas station?
A: Come to a stop. Put the transmission in neutral. Press start/stop button. Engine turns off, and the power system is switched to "accessories" mode.

Q: How do you turn the power off completely?
A: Put transmission in Park. Then press start/stop button

Q: What if I want to turn the power off and leave the car in neutral e.g. for maintenance?
A: You have to switch into Park first. The press start/stop. Then use the transmission shift override to select Neutral.

Q: How do you turn the car off in an emergency - e.g. stuck accelerator pedal?
A: You can't just press start/stop, as the vehicle speed sensor inhibits the button, so you can't turn off the ignition whilie the vehicle is moving. This isn't even in the manual. However, pressing and holding start/stop for 10 seconds will cause the ignition to turn off completely. This is a surprisingly long time in an emergency. In fact, in several "unintended acceleration" episodes, the drivers said they tried to turn off the push-button ignition, but couldn't turn it off.

Q: How do you give a prolonged crank, if the car fails to start (e.g. poor fuel, or cold weather)?
A: You have to let the computer attempt 3 failed starts. After that, the behaviour of the start/stop sequence changes. After the 3rd attempt, a momentary push of the button, will make the computer crank the engine for up to 30 seconds, for as long as the brake pedal remains depressed.

about 4 months ago
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Why Are We Made of Matter?

ChumpusRex2003 Re:Ah, antimatter (393 comments)

That's almost right. Nuclear fission reactions have a mass -> energey conversion of ~ 0.1%.

about 5 months ago
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Blender Foundation Video Taken Down On YouTube For Copyright Violation

ChumpusRex2003 Re:I don't get it (306 comments)

The summary is quite clear.
Blender produced the video, Sintel, and publish it to Youtube under the creative commons license.
Sony reuses the video as part of their 4k marketing material.
Sony provides youtube with a "reference" copy of their marketing material, and tells youtube to find copies of the material and to exercise Sony's rights over it.
Youtube finds the original Sintel video and matches it to a "reference" copyrighted work (Sony's marketing material).
Youtube arranges for forced commercial licensing of the Blender video with proceeds going to Sony.

about 5 months ago
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Blender Foundation Video Taken Down On YouTube For Copyright Violation

ChumpusRex2003 Re:Stop using Youtube (306 comments)

Which is more or less exactly what happens with the DMCA.

The accuser sends a notice to the hosting company saying they believe they are publishing infringing material.
Hosting company informs customer, and will remove content if no reply is received within 24 hours.
Customer responds, that they own the copyright, and once done hosting company restores the content, if removed, or does not remove it if the time period has not elapsed.

Once that stage is reached, the accuser must pay all costs and the video stays up until the case is closed.

The issue is that most providers will remove the material fist, and ask questions later - even though, they are permitted to leave the material for 24 hours to allow the accused to respond.
The other issue is that there is no penalty or cost for an accuser to make false claims under the DMCA. A malicious accuser can easily cause huge administrative headaches for hosting companies and content creators, and face no penalty or cost for it. Things get a lot more expensive and risky for the accuser at the 2nd phase once, and the number of copyright cases that progress after a DMCA counter-claim is very small indeed.

about 5 months ago
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UK Government Pays Microsoft £5.5M For Extended Support of Windows XP

ChumpusRex2003 Re:Why not use GNU/Linux? (341 comments)

There may not be a satisfactory alternative.

I was last month negotiating over the purchase of a results reporting and communication system. I spoke to one of the biggest suppliers and asked what platforms they supported: "We support Windows 7 with IE 8." "We're increasing moving to mobile devices, what support do you have for Windows 8, IE9, Mac OS, Android, iOS and other browsers such as Safari, Chrome and firefox". "We will be adding Windows 8 support in our next annual update, which will be available for the standard version upgrade fee. There are no plans to support any other browsers or OSs".

There are a variety of other products in this field, but they all have widely different features, integration capability (can it integrate with neighbouring hospitals systems, or primary care physician systems), etc.

If the only product which can provide your "core specification" is restricted like this, then you can't just go elsewhere.

about 5 months ago
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UK Government Pays Microsoft £5.5M For Extended Support of Windows XP

ChumpusRex2003 Re:Proprietary (341 comments)

Actually, they often do care about open-source, but in the wrong way.

I was recently purchasing some specialist medical software, and one of the key terms in the contract specified by senior management, was "the software should not contain any open-source components, except where no close-source alternative exists, and the vendor must ensure that appropriate restrictions over access to the source code are maintained at all times during the duration of the contract".

I managed to get that one negotiated to something less unrealistic (i.e. open source 3rd party libraries permitted), as the only realistic product choice made heavy use of technologies such as xuggler, libpng, openjpeg, etc.

The reason for this, "security". The management were adamant that "open source" was a catastrophic security risk, because "it exposed vulnerabilities in the software". They could/would not be educated on this matter.

about 5 months ago
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UK Government Pays Microsoft £5.5M For Extended Support of Windows XP

ChumpusRex2003 Re:Why not use GNU/Linux? (341 comments)

This is exactly it. I know one hospital that recently "refreshed" their hardware to new Quad core 4th generation i5 desktops. The OS - Windows XP SP1. Why?

The specialist medical applications that they run are too expensive to upgrade, and the version they run doesn't support XP SP2. Medical software is not cheap - something like a "results reporting system" which aggregates test results from multiple departments (e.g. blood chemistry, hematology, MRI, ultrasound, physiology, cardiology, etc.) and presents them to a physician - can cost $1million for the license. For a PACS (X-ray viewing and archiving) software, the license could easily cost $10 million for a large hospital (or group of hospitals).

If it would cost you $2 million to replace a specialist app, then you may be stuck with having to use an older OS - especially, if the app developer has gone out of business and you no longer have any support (very, very common in the medical industry).

Some of the more forward thinking IT departments have started rolling out Windows 7, and using some sort of virtualization service, to run the specialist apps under the appropriate OS/IE version/Java runtime/.NET runtime that each one needs. The difficulty with this, is that you essentially have not just your Win7 environment to manage, but also all the individual virtualized run time environments. The administrative burden that this requires can be substantial.

about 5 months ago
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MtGox Finds 200,000 Bitcoins In Old Wallet

ChumpusRex2003 Re:Smelling more fishy every day. (227 comments)

Yes. It is practical, and if you have a bitcoin client (with knowledge of your public key) running, it will show your balance in real time.

This type of setup is often called a "watch wallet" and a number of bitcoin exchanges have these set up as a method of auditing their transactions against their deposit/withdrawal database (to detect intrusions, database bugs, and to detect insider thefts).

about 5 months ago
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MtGox Finds 200,000 Bitcoins In Old Wallet

ChumpusRex2003 Re:What does "stealing" bitcoins mean anyway? (227 comments)

That is correct. There is no such thing as "a bitcoin" - instead, all you have are balances in a distributed public ledger.

Each balance has an associated public key pair. A payment instruction in bitcoin simply consists of a digitally signed message effectively saying "1Alice56789 pays 1.234 BTC to 1Bob12345 ". This message propagates around the network, and if Alice has sufficent funds to cover the transaction, and the signature is genuine, then the network will, in due course, add it to the ledger. If Alice doesn't have sufficient funds or the signature is invalid, then it will not be added to the ledger and the transaction will fail.

If you possess the private key associated with a particular "account", then you effectively control its spending power. All you need is the private key to the relevant "address" to control all the bitcoin held in it, or that may arrive in it, for all time.

It is not possible to transfer BTC without someone knowing. As soon as the transfer is confirmed, it appears in the public ledger. Similarly, because the ledger is public, if you know who holds the private key to a particular address, you know how many BTC they control.

In fact, on the day that Mt Gox claimed to have lost all their BTC, the general public knew that this was BS. Mt Gox had a couple of years ago, revealed the identity of some of their "cold" addresses. On the day of their bankruptcy, the bitcoin community had identified 200k BTC still held within these addresses, hence why the announcement was widely disbelieved. A competeing hypothesis to "transaction malleability theft" was that Mt Gox had simply lost their private keys to the BTC effectively resulting the in those BTC being forever lost. The fact that Mt Gox had started reorganising and moving these BTC to new addresses a couple of weeks ago, also had not gone unnoticed.

about 5 months ago
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Utilities Fight Back Against Solar Energy

ChumpusRex2003 Re:There must be a very good reason... (579 comments)

This is true. However, you cannot install grid-connected solar in the UK without permission from your local electricity distribution network operator (DNO).

There are now significant parts of the county where the DNOs routinely deny permission because the grid is saturated.

about 8 months ago
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Utilities Fight Back Against Solar Energy

ChumpusRex2003 Re:There must be a very good reason... (579 comments)

Because it is exceedingly expensive to do so.

The issue is that of voltage tolerance. The grid is designed to supply power form central to peripheral. The central voltage is held higher than peripheral, so that the expected voltage drop through supply impedance will result in a voltage at the customer premises which is within tolerance.

If current flow is reversed through the high impedance "last mile", then you can get severe voltage elevation at the point of connection of the generation. This can result in equipment damage (usually the customers) and legal problems for the electricity network operator.

The only way to deal with this problem is to increase the "prospective fault current" of the customer circuit by reducing the system impedance. This isn't something simple like replacing transformers, it is extremely expensive and requires repalcement of cabling with heavier gauge wire, upgrade of safety equipment to withstand the higher fault currents, and may require uprating of transformers and switchgear to handle the magnetic and thermal forces of a fault on the now upgraded circuit.

There are other issues too. Grid transformers are often not designed to operate in reverse power - the tappings are designed for voltage drop in the direction of HV to LV. Under reverse power, there may be insufficient tap range to get satisfactory voltages. Only way around this is to replace the transformer.

Finally, there are second order effects, such as reduced efficiency of transformers when operated in reverse power, due to higher levels of flux leakage from the secondary (primary windings usually go nearest the core, so that stray flux cuts through the secondary and transfers power).

about 8 months ago
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Online Shopping: Hazardous To Junk Food's Health

ChumpusRex2003 Re:Or, maybe (151 comments)

Actually, as cereals/grains make up a large part of the modern diet, the fact that they are poor sources of certain vitamins becomes relevant. For example, breakfast cereal commonly has folic acid added, not because it was lost during process (although some is), but because it is an important public health measure. Same for flour for bread making.

Additionally, some nutrients will be lost from processing - usually cooking, as most breakfast cereals are baked. Many vitamins are heat unstable and are therefore added back by the manufacturers.

about 9 months ago
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Can the US Be Weaned Off Ethanol?

ChumpusRex2003 Re:Ethanol is a crock nobody wants (330 comments)

Ethanol can be a big problem with certain modern cars.

Toyota and its luxury devision, Lexus, have this problem with models up to 2008. For example, the 2008 Lexus IS (built during calendar year 2007) is not E10 compatible. In areas where E10 fuel was legally mandated, lexus noticed a high rate of warranty replacements of the fuel injection pump and fuel injector failure, as well as fuel leaks from the fuel injection manifold. This was found to be ethanol induced corrosion of the metal alloys used in the injection pump and manifolds. Oxidation and debris from the corrosion would also clog injectors or cause them to leak.

These cars were recalled in the US, but were not recalled outside of the US. Customers with these cars who are now out of warranty are potentially SOL, if they live in an area where E10 is expected to be mandated shortly.

It's not just recent Japanese cars that have problems with E10. Recent european cars also have major problems with E10. Mercedes-Benz vehicles built between 2002 and 2005 are not E10 compatible, as are numerous post 2000 Fiat vehicles, Audi/Volkswagen/Seat/Skoda vehicles with direct injection systems built before 2006, etc. The list of non-compatible cars is very long.

about 9 months ago
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NYC's 250,000 Street Lights To Be Replaced With LEDs By 2017

ChumpusRex2003 Re:How many people will die because of this? (372 comments)

I sense some exaggeration here. In the US CFLs never got that cheap in any size that I've ever seen, even at the mass discount stores. That must have been some massive government subsidy.

Not an exaggeration. Many stores would sell subsidised CFLs for about that price. Same with other energy saving products (I'd seen rolls of thermal insulation material - 10 yards, 6" thick on the shelves at hardware stores for about $2-3 each; but there were big warnings on the shelves which read something similar to the followion - warning! for personal domestic use only. Commercial use of this product is illegal. By purchasing this product, you certify that it will not be resold, used in the course of business or in the construction of a new building)

In fact, the energy suppliers had "energy reduction" targets to meet, and huge fines were levied if they didn't spend $x per year on assisting customers to use less energy. A common way for the energy companies to do this, was to buy massively cheap CFLs from China, claim the cost as a "green expense" and then just mail out unsolicited boxes full of CFLs to every customer. That really did happen, and the bulbs were the lowest possible grade available. The best bit, was that the energy companies could claim the cost of the CFLs as a "green expense", and the government would fund them. Where did the govt get the money from, it came from a surcharge on energy bills. It was even better for the energy company, if they could get a kick-back from the CFL vendor as part of a big order at list-price.

The cost of these "green projects" added to domestic energy bills comes to about $250 per household per year, accounting for about 15% of the total cost.

about 10 months ago

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