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Comment: This might not be a good idea ... (Score 5, Interesting) 94

by Cassini2 (#49706625) Attached to: In-Database R Coming To SQL Server 2016

The problem with R is that everything is a vector. When you hit something as big as a multi-terabyte database, the vector doesn't fit in memory anymore. An interpreted language like R, and even many compiled languages, expect memory accesses to be quick. However, if the data accesses are requiring SQL calls, then the R-SQL server marriage will be very slow. I'm sure they will be able to do some small demonstrations that look quick, but once the database becomes large, then things will be very slow.

On the good news side, there are some operations like average and standard deviation that reduce into loops of sums. Those should map onto SQL queries relatively well.

On the bad news side, a popular operation is to build a covariance matrix. With a large data set, it is easy to create a covariance matrix that does not fit into RAM.

R would be a better match against an distributed database (NoSQL, MongoDB), where the memory requirements of the vectors could be split across multiple computers. Although, that too might require some changes to R.

Comment: Is this an Arduino product? (Score 2) 42

by Cassini2 (#49704905) Attached to: Linino-Enabled Arduino Yun Shrinks In Size and Cost

Whatever happened to the Arduino vs Arduino suit?

What makes hardware is great software support. I would hate to wind up with a piece of hardware that can only run a small fraction of the Arduino software.

Also, along those lines, is OpenWRT a friendly enough distribution to make the user experience as easy as it is with the old Arduino?

Comment: Re:Ok.... Here's the thing, though ..... (Score 1) 533

by Cassini2 (#49527593) Attached to: Utilities Battle Homeowners Over Solar Power

I think the Navy ships use turbines that are similar to the ones used for power generation. However, the are differences, because of the fuels used, and the marine application. Also, some (many?) ships use steam turbines. There are lots of different types of turbines, (and the Navy doesn't like to spill its secrets.)

This is also why the Navy has engines that can run on almost anything, but fighter planes require a specific type of jet fuel. It depends on what you are building.

Comment: Re:Ok.... Here's the thing, though ..... (Score 1) 533

by Cassini2 (#49527505) Attached to: Utilities Battle Homeowners Over Solar Power

There are small turbines located near key loads that are expressly designed for rapid start/stops. However, the size and design of the turbines matter. There are advantages to using different units to power large fractions of the grids load.

I looked up your coal statistics. You are right in that a small modern coal plant can start fairly quickly. However, there are a great many old power plants out there, and some take days to start (and stop). You can't assume that a power plant near decommissioning will perform as well as a freshly built plant.

A big provider will have a large mix of generating capacity. This gives them the capability of using the cost-optimal station at any point in time. Historically, before wind-power arrived, it wasn't necessary to design power stations to deal with rapidly changing distributed power inputs. Also, when applicable, there are efficiency advantages to implementing combined cycle power plants, and the thermal time constants involved are such that it is difficult to spool up a second cycle quickly. There is a great deal of complexity in making decisions that minimize costs while maintaining grid reliability.

Comment: Re:Hold it (Score 1) 649

by Cassini2 (#49515115) Attached to: Automakers To Gearheads: Stop Repairing Cars

If the automakers can use the DMCA, then they can make it so the only source of expensive repair parts is the OEM itself. Using the DMCA, every module that contains a computer can be made expensive and tough to replace, and require trips to the dealer for service. Initially, it will start with the expensive stuff, like the ABS sensors, the engine sensors, the engine ECU, the body control computer. Eventually, even stuff that doesn't really need computers, will include them.

And the HP and Lexmark toner cartridge cases which were just about embedded serialization

Exactly. The automakers want to follow the same strategy as the ink manufacturers. Want a new engine filter, it must be an AC Delco filter. Sooner or later, frequently replaced parts of the car will get micro-chips to boost repair revenues.

Comment: Re:Ok.... Here's the thing, though ..... (Score 1) 533

by Cassini2 (#49508037) Attached to: Utilities Battle Homeowners Over Solar Power

I worked on natural gas turbines. Going from a dead standstill to full on within one minute with any frequency will void the warranty. The thermal stresses involved from going from cold to hot are significant.

You are correct in that a hot unit can handle smaller variations in load relatively well. However, these decisions are not taken without analysis. Ontario would not pay outside operators to idle turbines unless it was the cheapest option. Historically, Ontario did not have sufficient NG capacity to spool up and down and make everything work.

Comment: Re:Ok.... Here's the thing, though ..... (Score 4, Informative) 533

by Cassini2 (#49505255) Attached to: Utilities Battle Homeowners Over Solar Power

Batteries are not cost-effective. The electrical grid must always be balanced. As such, utilities try to find methods of stabilizing the grid without using batteries. Technically this works. However, the economic impact of the guaranteeing a market for subsidized solar and wind power, is another set of hidden subsidies. Ironically, some of these hidden subsidies are going to fossil fuel companies.

To make a complex story short, the grid must always be balanced. If the power source cannot be controlled (like solar), or if the power source is unreliable (like wind), then it is necessary to make up the difference in some other way. The cheapest methods are to remotely turn on and off loads, and to remotely turn on and off generating stations.

The problem with starting and stopping loads is that there are not many loads that can be turned on and off remotely, and still accomplish something useful. Ontario has been experimenting with ways to turn off home air-conditioners during the day. Also, big consumers often get a preferred electricity rate, with the understanding that their electricity is "interruptible". However, there is only so much that this can be pushed. People want a cool house. The price of "interruptible" electricity is a few cents per kWh, which is often below cost.

This brings us to starting and stopping generating stations. A nuclear station takes days to start and stop. A coal station takes on the order of a day to start and stop. A natural gas turbine take about 3 to 6 hours to start. Natural gas (NG) turbines have the ability to run at a "hot-idle", but this is expensive. At "hot-idle" an NG station is still running, it is just not producing power. Hydro power plants (hydro dams) can be started quickly, however unexpected rapid changes in water levels have killed people downstream. As such, very few generating stations can turn on and off as quickly as wind-power changes.

Probably the best way to solve the problem is to have many small power plants, either small hydro-dams or small NG-turbines, and only turn on and off a fraction of those units at any one time. If the grid operator is required to purchase significant amounts of wind-power, then the grid-operator might have to go very far afield to find a sufficiently large enough pool of existing small generating stations that can be started and stopped quickly. In the case of Ontario, Canada, it needed to pay US power plants to not produce electricity to keep the grid balanced. Ontario has a large energy grid, however Ontario was not large enough to deal with wind-power's fluctuations without external help.

In the case of Ontario, which is purchasing solar at 90 cents/kWh and wind at 17 cents/kWh under certain existing contracts, then a "hidden" solar/wind subsidy is going to mines and smelters and fossil fuel producers to keep the grid balanced. This subsidy is cheaper than battery and capacitor banks. However, conservation is far cheaper than many of the above schemes.

Compared to solar/batteries, conservation is the way to go. LED light bulbs almost make sense at current electricity prices. At 90 cents/kWh, converting existing fixtures to LED light bulbs is cheap. Appliances can be moved from electricity to propane or natural gas. Stoves, hot water heaters, furnaces, and even the fridge and air-conditioner can be converted. This is cheaper than paying for battery storage. What little load is left, can then be powered off a roof-top solar / battery system. Conservation is by far the cheapest option.

Comment: Re: Too many pixels = slooooooow (Score 1) 263

by Cassini2 (#49418347) Attached to: LG Accidentally Leaks Apple iMac 8K Is Coming Later This Year

The Hercules graphics card fixed the limitations of MDA, and back in the early days, they had the highest resolution graphics available on a PC.

I remember writing circuit board design software on Windows 2.03 in monochrome graphics on a 286 PC! It was the best thing out there.

Comment: Look at the table in the PDF (Score 5, Informative) 71

by Cassini2 (#49411297) Attached to: USPTO Demands EFF Censor Its Comments On Patentable Subject Matter

In the PDF, there is a table in the PDF of the EFF's response where it compares the issued patent against the rejected patent at the Supreme Court. The wording is amazingly similar.

The significant change between the two is patents swapping the words "banking transaction" for the use of "a credit or charge account", and then updating the rest of the text appropriately. If you do not understand what the EFF's point is, then take a look at the table. It does not take much imagination to see that the patent at stake in the Supreme Court case, and the newly issued patent, are almost identical.

Comment: Two Graduates for the same amount of work! (Score 1) 121

by Cassini2 (#49404193) Attached to: Stanford Turns To Pair Programming: 1 CS Education For the Price of 2?

If this course goes the way of the intro-CS classes of old, then one person will do all of the work, and the other will be bewildered and lost. Once expanded to the entire curriculum, the graduates will be evenly split between the learned and the lost.

I often wonder if programming is an inate ability that can only be polished and improved. It is like fine art or music, it is immediately obvious who the great performers will be. The brilliant students eclipse the teacher in ability. As such, the rote of the teacher is to expose the students to the ideas and works of the great masters, and to help the student with their carreer.

Comment: Re:BCD mode (Score 1) 140

by Cassini2 (#49402157) Attached to: Building an NES Emulator

BCD mode is used extensively in COBOL and in the banking industry. Also, conversions between binary and decimal numbers are really slow on processors that lack a multiply, divide or mod instruction. If the only divides and multiplies are by 10, then BCD math is quite competitive on an 8-bit processor. With the right workload, it is also competitive on some 16-bit processors.

Many older and/or embedded processors lack a fast or single-cycle multiply and divide instructions. For instance, 8080A, 8085, 8088, 8086, 80186, 80286, 80386, 68000-68020, Microchip PIC, Z80, Z8, 8052 and successors, they almost all lack really fast multiply and divide instructions. The 80386 used 9 to 41 clock cycles on multiply. The dsPIC33E is a relatively modern embedded DSP from MicroChip. It takes 18 clock cycles to do a 16-bit divide. I try hard to avoid a 32-bit divides in critical real-time code.

A triangle which has an angle of 135 degrees is called an obscene triangle.

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