designtofly

That's not a fair comparison. If you looked at one of the early slides in the presentation that the slide in question came from, you can see that NASA decision makers are trying to balance three conflicting objectives: 1) Budget realities, 2) risks, and 3) benefit to stakeholders. This is no different than any corporate board. The stakeholders of NASA are the American people. As such, NASA has a duty (implicit or otherwise) to bring as much benefit to the American people as possible. It does this through several avenues. One of the biggest, and one that is often overlooked is the amount of knowledge that NASA has generated. You show me one for-profit company that has been as open as NASA at making all of their information public and available. [1] Secondly, it would be naive to think that NASA does not have an obligation to provide benefit to their stakeholders by providing jobs.

With this framework in mind, what objective is the car designer trying to balance when deciding to use more steel? If the writer decides to use more words, what objective are the trying to meet? The first case you bring up is ridiculous and I'm not going to address any further. The second case is more fair. The novel writer does have to balance clarity of writing and the amount of pleasure they bring to the reader. Someone buying a 50 page book is going to feel pretty ripped off if they read it in 30 minutes. Why are the Harry Potter books so damn long? Because people love to read them. She could have just as easily written the same story in a lot shorter format if she had so decided.

[1] http://ntrs.nasa.gov/search.jsp

This slide is taken out of context to support the author's own ideology. First off, this slide describes only one of 13 criteria used when deciding on alternatives. This is certainly not the focus of the presentation. This presentation is showing the multitude of objectives that NASA decision makers must take into account when deciding on the future of their program. This is strictly an exercise in Multi Attribute Decision Making [1]. In general, with MADM techniques, you frame the objective as a weighted combination of criteria that you meet with appropriate weightings. We have no idea what "weights" (i.e. importance) were put to this criterion of maintaining workforce.

What is wrong with framing _this particular issue_ in this way? Why would any organization, especially one heavily based on knowledge gathering, prioritize a reduction in workforce. Anyone who understands the issues of the aerospace workforce knows that knowledge retention is one of the most important issues facing the industry right now. All of the smart people that got us to the moon and created all of the other aerospace accomplishments of the last 50 years are either retired or very close to retiring. Y'all should understand that people are assets.

As an aside, the reason that NASA is so expensive is because it is risk averse. It is risk averse because the public (and Congress) cannot tolerate any failures. They are reacting to public sentiments any time something goes wrong. They have some of the best risk and reliability assessments of any industry (even though they are not perfect). The ONLY way private companies can do better is if they accept more risk. As soon as NASA tried to accept more risk, they were blamed incessantly for having a "management driven culture." What do you think a private company is going to do?

[1] http://www.google.com/search?hl=en&q=multi+attribute+dec...

I think you've missed the point of what they are doing. Of course, I may be wrong as well since this is the first that I've seen of this instrument, but here is my take of what they are doing. They are sampling the vibrations of the small guitar top in strategic places using piezo sensors. From this information, they are extrapolating the information using a digital computer to emulate the sound of a complete guitar. What you are hearing in the video is not just the sound of the small wooden inset. If you skip to ~1:55 in the video, you will see their animation of the vibration patterns on a full-sized guitar. My question would be whether they would really be able to determine and emulate the vibration patterns of any guitar top while only sampling 5 (?) locations relatively close to the bridge of the guitar.

As far as the pickups go, even though they might look cheap, they are insignificant and operate completely different than electric guitar pickups. All they need to do is provide the frequency information which is processed by the digital computer. You aren't actually hearing the analog output from the pickups.

I also don't see this guitar as a competitor to digital amps with effect processors.

Over time? That was 3 months ago.

What you call a "nice gesture," most everybody else calls collusion [1].

[1] http://en.wikipedia.org/wiki/Collusion

It's interesting that you brought up the car, so let's use that example. Would you argue that you should have the ability to remove emissions-regulating devices from your car? After all, they add weight, complexity, and reduce power.

We have emissions regulations. We also have the DMCA which prevents anti-circumvention of piracy protection measures (which the modifications in question aim to do). We, as a society, have generally agreed that emissions regulation is important. We have also agreed that software piracy undermines the viability of the computer/electronics industry.

It's not as black-and-white as "it's mine and I should be able to do anything I damn well please." These modifications have an effect on society at large. In the case of the car, your "right" to modify your car does not trump the rights of society to not have to deal with whatever modifications you deem you deserve. Similarly, even game console modifications have externalities and effects on the industry. They damage the online gaming ecosystem. They reduce revenue. The prevent game consoles from patching and regulating online play.

The purpose of the modifications is to run pirated games. I don't see anything illogical or indefensible with these companies (and the government) going after people who modify hardware in order to run pirated software.

This particular modder crossed the line between hacking for fun or knowledge to facilitating a crime. I know the "criminal" aspect might not get a lot of sympathy from the pro-piracy contingent on this site, but it's still a crime. If you don't want people like this to get arrested, then call your congressmen.

Pretty harmless? I'll admit that I don't know much about this case, but this bit seems to indicate otherwise:

"Mr McKinnon admits that he hacked into 97 US computers from his bedroom in north London between 2001 and 2002 and left a message on one machine saying: "I will continue to disrupt at the highest levels.""

Two years, almost 100 computer systems, taunting and threats.. that doesn't sound so harmless to me.

[1] http://www.telegraph.co.uk/news/worldnews/northamerica/usa/5...

In the same vain, we should also discourage upvoting simply for agreement. There is no reason why one-liners should get upvoted to very high scores. Upvotes should reward content and thoughtful discussion.

By any objective measure, iTunes has a monopoly with 87% market share in 2008. [1] Therefore, it can claimed that any actions against competitors can be construed as abusing monopoly power. Yes, there are other media players and other phones and other ways to buy media. However, the precedent is clear that Apple has "enough" of a monopoly to take these claims seriously. These claims are at least as serious as those launched against Microsoft in the 90's and in the EU-led accusations currently.

[1]: http://news.cnet.com/8301-1023_3-10213149-93.html

I disagree. We're talking about the most closed-off and spiteful technology company here (who do make very pretty products). Not only that, but why in the world would the "security" issue be a more logical when Tim Cook said the following:

"However, we will not stand for having our IP [intellectual property] ripped off, and we’ll use whatever weapons that we have at our disposal. I don’t know that I can be clearer than that." [1]

[1]: http://brainstormtech.blogs.fortune.cnn.com/2009/01/26/apple...

Well, I think the half price sale was a very smart move on Microsoft's part. By the end of the promotion, it was sold out on Newegg.com, and it dominated the software category on Amazon. This created a lot of buzz and demand over a short period and generated a lot of positive publicity.

Microsoft's biggest mistake with Vista was not controlling the PR. This promotional campaign lets Microsoft create a big enough lead-in demand so that it will continue to build until the actual release date.

In the end, IMHO, I think that Microsoft will continue to offer these promotions for its retail customers up to and after the official launch. Hopefully they realize that, for retail buyers, Windows 7 MSRP is still too high. They need as many people as possible upgrading, but not at the expense of the corporate buyers. Therefore, I think they will continue to offer promotions for retail buyers at pretty heavy discounts.

I'll also chime in to say that I was pretty impressed when running Windows 7 RC for a few days to test it out. Coming from XP, it was very fast and intuitive interface. I ordered 2 copies of the Professional Upgrade edition during the promotional period.

He means that solar and wind power (and other renewable energy sources) represent only a tiny fraction of power generation in the US. Therefore, using them as a justification for the "clean" generation of hydrogen just doesn't make the case.

He is right that they are indeed "rounding errors." The DOE's own data shows that "Wood, black liquor, other wood waste, biogenic municipal solid waste, landfill gas, sludge waste, agriculture byproducts, other biomass, geothermal, solar thermal, photovoltaic energy, and wind" contributed to only 3% of total energy production in the US in 2008. [1]

[1] http://www.eia.doe.gov/cneaf/electricity/epm/table1_1.html

It is not traded in the same form it was prior to the bankruptcy. It was delisted from the NSYE and its symbol was changed. It is now GMGMQ and is traded over-the-counter (OTC). [1] This is the method that most penny stocks are traded through. This is not a formal stock exchange.

[1] http://www.investopedia.com/terms/o/otc.asp

Aircraft with Wide Area Augmentation System (WAAS) are certified to use GPS as a primary navigation source. [1] [2]

[1] http://www8.garmin.com/support/faqs/faq.jsp?faq=221

[2] http://en.wikipedia.org/wiki/Wide_Area_Augmentation_System

No, the GPS is not a reliable backup device. The issue is not latency. Aircraft GPS systems generally update faster than 1 Hz, which is plenty fast for most things. The real issue is that GPS gives you the ground speed, and not the airspeed. The wind speeds at 30,000 ft can exceed 200 knots [1]. Therefore, depending on the wind speeds and direction of travel, your airspeed and ground speed can be vastly different. Of course, it is theoretically possible to correct the GPS groundspeed using weather data (would have to be downloaded from external sources) to correct for upper winds, but this is not reliable over much of the surface of the world.

[1] http://en.wikipedia.org/wiki/Jet_stream

Credit to iends who found this during the previous discussion of this topic: http://news.ycombinator.com/item?id=662254

Original thread: http://news.ycombinator.com/item?id=662200

It seems that the reason that this type of strategy is so rampant and insidious is because it makes it easy to substantiate cost cutting goals using unrealistic bids from inexperienced subcontractors. The costs that often go neglected in the whole process is the added managerial costs that go along with any outsourced work. For most projects, especially complex ones (as is aircraft design and manufacture), the overhead costs can easily outweigh initial cost saving estimates from outsourcing.

More importantly, it is a very short sighted strategy that favors short term cost savings against the long term institutional knowledge that will help sustain it in the long term. With the incredibly long development and production cycles, Boeing might not have the appropriate capabilities in the long term. While Boeing did do the initial design on the 787, they have outsourced much of the detailed manufacturing design to their vendors, leaving an important knowledge gap.

Here is an interesting presentation titled "Is Outsourcing Profitable?"

http://www.strassmann.com/pubs/gmu/OutsourcingV6.pdf

It presents some case studies and findings that do not substantiate the cost savings claims of outsourcing.

Only if you believe Elon's side of the story (I don't).

If you believe Martin Eberhard, here is his take:

Martin: "The 2-speed transmission was the first major edict to come from Elon, and though I thought it was an unnecessary risk for the first model year's cars, I was certainly willing to be a team player and support Elon's edict. I knew there were risk and cost associated with the decision, but by themselves, I felt we would be able to manage them."

Editor: Here's an another example of how different people see the same events through their own personal filters. Musk acknowledges that he pushed for the 2-speed transmission from Job 1 in order to meet the original performance targets. From a December 2007 interview in Inc. magazine: "The most controversial of Musk's edicts involved the transmission. Martin Eberhard, Tesla's co-founder and then-CEO, argued that it would be quicker and easier to build the car with a single-speed transmission. Musk ordered a two-speed model so that the Roadster would be able reach a top speed of well over 100 miles per hour."

Of course, it's never quite that clear cut. My belief is that Elon's ego and pocketbook far exceeds his engineering and management ability.

This was from a very interesting piece done by Autoblog Green:

Part 1: http://www.autobloggreen.com/2008/06/23/autobloggreen-qanda-... Part 2: http://www.autobloggreen.com/2008/06/24/autobloggreen-qanda-... Part 3: http://www.autobloggreen.com/2008/06/25/autobloggreen-qanda-...

You're correct in that being in the "coffin corner" is not dangerous in itself. In straight-and-level flight, if you go any faster, the extra drag will slow you down. If you reduce your thrust from your engines, you will slow down and lose altitude.

The problem comes about if you enter into any unusual attitudes, which is certainly possible in severe turbulence. The most important part would be a safe recovery to straight and level flight. An unusual attitude can put you in a situation where you overspeed the aircraft (e.g. nosedive). Above the maneuvering speed of the aircraft, you must be very careful to regain control without overstressing the airframe.[1] If your speed sensor(s) are giving you or the autopilot faulty readings, it would be very difficult to know the safest way to regain control of the aircraft after being put into an unusual attitude due to turbulence.

[1] American Airlines Flight 587 crash (NY, 2001) taught us that even below the manuevering speed of the aircraft, the airframe can be overstressed due to dynamic loads from pilot control inputs.

"Thunderstorms are the "tallest" weather phenomena that we experience here on the ground. An "average" height of thunderstorms is 30,000, however, depending on atmospheric conditions (i.e., the height of the tropopause) some thunderstorms can reach as high as 50,000 to 60,000 feet over the central U.S. and in the tropics near the equator. In some stronger thunderstorms, the upward vertical motion in them can "punch" through the tropopause and will actually penetrate into the stratosphere before stopping their upward growth."[1]

"The Airbus SAS A330-200, with 228 on board, appears to have flown into or near a large cluster of thunderstorms northeast of Fernando de Noronha, located off Brazil’s coast, according to AccuWeather.com.

Updrafts may have reached 100 mph, and the storms, stretching for over 400 miles (644 kilometers), towered as high as 50,000 feet, according to the weather service." [2]

Airbus A330 Service Ceiling: 39,370 ft (12,000 m) [3]

[1] http://www.srh.noaa.gov/shv/Past_Questions_FOUR.htm

[2] http://www.bloomberg.com/apps/news?pid=20601085&sid=aFSn...

[3] http://www.aerospaceweb.org/aircraft/jetliner/a330/

The answer is right there on the linked page.

Q: How is Mathematica Home Edition different from the professional version of Mathematica?

Mathematica Home Edition is a fully functional version of Mathematica Professional with the same features.

I completely agree with you! The same should be said for genetic algorithms. I don't understand the obsession around here with both ANN and GA. They are interesting tools, but they are not some holy grail with unlimited applications.

Both of them are inefficient and rarely the right tool for the job. GA and ANN are used for situations where you don't care about how you got to the solution and what it took to get there, as long as you get close to it in the end.

The physical phenomenon is called multipath and can become an incredibly difficult and important problem in many applications (e.g. radar guided missiles).

http://en.wikipedia.org/wiki/Multipath

The analysis you linked to does not refute anything said here. In fact, the conclusions of the study you showed are a necessary assumption for this problem (that each gender has an equal probability and independent of birth order). This problem has nothing to do with biology but rather using posterior information to come up with a probability given a statistical experiment.

However, I did not vote you down.

I would advocate a system similar to that used in trademark infringement cases.

From http://cyber.law.harvard.edu/metaschool/fisher/domain/tm.htm

If a party owns the rights to a particular trademark, that party can sue subsequent parties for trademark infringement. 15 U.S.C. §§ 1114, 1125. The standard is "likelihood of confusion." To be more specific, the use of a trademark in connection with the sale of a good constitutes infringement if it is likely to cause consumer confusion as to the source of those goods or as to the sponsorship or approval of such goods. In deciding whether consumers are likely to be confused, the courts will typically look to a number of factors, including: (1) the strength of the mark; (2) the proximity of the goods; (3) the similarity of the marks; (4) evidence of actual confusion; (5) the similarity of marketing channels used; (6) the degree of caution exercised by the typical purchaser; (7) the defendant's intent.

I would say that in this case, the OP's argument fails in just about all of those factors listed above. The true trademark holder has exclusive rights to market their product as they see fit.

There is no "Tim Daily" that is employed by the AISD.

http://www.austinisd.org/inside/directory/index.phtml?alpha=...

What's also interesting is how it will affect what airliners look like. These engines pose a very significant problem for integration onto an aircraft. Projected diameters for an engine of this type range from 12-17 feet. Compare this with a diameter of about 56-60 inches on a current high bypass engine as found on a 737.

Picture: http://seattletimes.nwsource.com/ABPub/2006/05/09/2002983476...

Article: http://seattletimes.nwsource.com/html/businesstechnology/200...

Yes, it is generally true. There is not a big dependence on flight speed because the inlet on jet engines slows down the flow before it enters the engine. So even though an airliner might be flying at Mach 0.85, the face of the engine only sees about Mach 0.3. The reason the duct improves the thrust of the engine is because it reduces the pressure losses (improves efficiency). A fan (or any stage in the engine compressor) increases the pressure of the air. Since air moves from high pressure to lower pressure, the air that you just pressurized wants to sneak back around to the front of the fan around the tips. By putting a duct around the fan, you help keep air from sneaking back and robbing you of the work that you just did on it. In fact, the efficiency that you gain is highly dependent on the clearances between the duct and the tip of the fan. A lot of work goes into reducing these clearances as much as possible. You can imagine that that is a non-trivial task since the parts of the engine expand and contract based on temperature, and also vibrate and have dynamic structural behavior.

That was certainly a big part of it. Jet engines, although revolutionary, were developed only about 40 years after heavier-than-air flight began. It's hard to group all jet engines into a single category and discuss trends of the entire group. One grouping you could make is the distinction between turbojets (and very low bypass turbofans) and medium/high bypass turbofan engines. With turbojet engines (like the original designs starting from the 1940s), you had the ability to produce a lot of thrust at the expense of fuel consumption. These are the types of engines that you had in military jets and supersonic planes like the Concorde.

However, for modern airliners, fuel consumption is important. So a second class of jet engines was used that send a small portion of the air through the "core" of the engine, where it is burned and power is extracted, and the majority of the air is accelerated through the fan without being combusted. This is much more efficient (and much quieter, since most of the noise you hear is from the interaction of the high speed air coming out of the engine with the surroundings). The open-rotor concept described in this article is just a natural extension of the high-bypass engine. You get a much more efficient engine when you can increase the ratio between the amount of air that you accelerate through the fan compared to how much you send through the core and burn (this is called the bypass ratio). Since the weight and drag penalty increase exponentially as you increase the size of your engine, removing the duct around the fan becomes necessary once you get to very large bypass ratios.