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Comment: Re:The UK Cobol Climate Is Very Different (Score 1) 225

by AaronW (#47924685) Attached to: College Students: Want To Earn More? Take a COBOL Class

I consider my workplace a professional workplace. In my group we're working on the Linux kernel, networking code and in my case bootloader code for some massive embedded processors (right next to me I have two 48-core 64-bit processors running in tandem (total 96 cores) with 40Gbps ports hooked up. Nobody in my group, from the manager on down wears a suit. If I wore a suit to any of the engineering jobs I've had since college a lot of questions would be raised. A number of people commented on the fact that I did wear a suit when I just started out because I was the only one.

I don't think they care what we wear as long as we're wearing clothes.

Then again I live and work in Silicon Valley but it was the same way when I visited our other engineering facility in Massachusetts.

Comment: Re:reading the results wrong (Score 2) 207

by AaronW (#47895763) Attached to: Early iPhone 6 Benchmark Results Show Only Modest Gains For A8

The problem with phones and tablets is they're pushing more and more pixels despite the fact that they're already smaller than what you can see. The drawbacks of having more pixels are that less light passes through and it takes more processing power to manage all of those pixels. My 7" tablet does 720P resolution. I can't see a discernable difference between a tablet with more pixels. The differences I see are things like how well they display color and viewing angle and brightness.

Comment: Re:Unfamiliar (Score 1) 366

by AaronW (#47887873) Attached to: The State of ZFS On Linux

I can do most of those things using my old Areca hardware RAID controller and XFS.

Data integrity is maintained in my RAID array which has its own battery-backed ECC memory. I can grow and shrink logical volumes on the fly. I can change the striping or even the RAID level without any downtime. I replaced all of the drives in my RAID array (one at a time) with larger drives with zero downtime.

Running XFS makes it easy to do incremental backups or doing the equivalent of DD on a mounted filesystem using xfsdump. It also supports defragmentation while mounted.

The RAID array also does data scrubbing and runs all of the SMART checks.

I can easily add more capacity without downtime, just drop another disk in the array and add it.

While I can't do snapshots or native compression, I can do most other things. Compression would do nothing for me since most of my data is already compressed. I run continuous backup software to back up onto removable SATA drives as well as to a cloud backup service (Crashplan) which encrypts everything. It maintains snapshots of everything and I have several TB backed up that way.

While I haven't played with ZFS, I did try out BTRFS but had to throw it out. Performance was abysmal on the SSD I was using and without a clear way of knowing how much space is free is a major issue. If everything is snapshotted, how do you deal with deleted files when you run low on space? The performance of trying to put my IMAP server on it was unusable. I gave up after a couple of hours trying to write all of my emails to it on a SSD. On XFS or EXT4 it takes a fraction of the time, despite it being hundreds of thousands of small files.

Also, I can still run bcache or some other method of using a SSD to cache my data.

I have been using XFS for years and always found it to be reliable, more so than my experience with EXT2/3/4 though I'm also one of the rare people who never had a problem with the killer Reiserfs. My IMAP server ran for 10 years on Reiserfs with the same hard drive with uptimes on the order of years before I finally retired the machine (the hard drive has over 10 years of uptime according to SMART). The only major problem I had was that the Linux kernel had a bug where the uptime would wrap after 497 days. After that happened a few times I finally had to reboot the computer when the UPS died and it loaded an updated kernel.

+ - Researchers Closer to Industrial Graphene Production Due to $10 Bet->

Submitted by AaronW
AaronW (33736) writes "After trying and failing to convince Nina Kovtyukhona to test her technique of separating layers of graphite and boron nitride to instead try graphene, Thomas E. Mallouk made a bet with Nina that her technique method would work. If it worked, Nina would owe him $10. If it didn't, he would owe her $100. Thomas is now $10 richer and we are now a step closer to industrial scale graphene production."
Link to Original Source

Comment: Re:They are stagnant (Score 3, Interesting) 157

by AaronW (#47828037) Attached to: Tesla's Next Auto-Dealer Battleground State: Georgia

I agree with you. I'm also the owner of a Tesla (18 months, 19K miles). Tesla is constrained by batteries. They can't make them fast enough. There's also a huge demand for the model X with thousands of pre-orders yet it is sight unseen. This is from a company that does no advertizing other than their showrooms.

Comment: Re:Probably not. (Score 2) 546

by AaronW (#47820103) Attached to: Does Learning To Code Outweigh a Degree In Computer Science?

In my case I studied computer engineering. I did not take a programming class per-say. I took classes where you were expected to learn the programming language but it was more about the algorithms than the language. For example I learned C in my first upper-division algorithm programming class but most of our time was not spent on the programming language.

My degree also gave me access to a lot of things that would not be easily doable outside of the university such as a lot of hardware concepts. A lot of what I learned was also hands-on. For example, we designed and built our own CPUs and systems built around the CPUs. Back when I did it it was a combination of wire wrap and FPGAs and a number of discrete chips. We had access to the various data sheets and learned about concepts like fan-out, propagation delay, glitch free logic and more.

The skills I learned in college I use to this day even though it was 20 years ago and those skills are in high demand. It would be far more difficult to be self-taught in all of the knowlege I learned there. What I learned in college gave me a good start to continue learning once I joined the industry and where I continue to expand my skills where I work on the bootloader and the Linux kernel for multi-core 64-bit MIPS CPUs (currently 48 cores) and high speed networking (40Gbps).

Comment: Re:Coal is vegetation, i.e. Trees (Score 1) 708

by AaronW (#47769691) Attached to: Climate Damage 'Irreversible' According Leaked Climate Report

There also was a long period of time where fungus and bacteria were unable to digest lignin so dead plant material would just accumulate. This is what formed most of our coal. Only later were fungus and bacteria able to evolve mechanisms to break down and use the lignin.

While it is possible to sequester plant based carbon, it would require heating it to charcoal and burying it in order to prevent it from being recycled back into the atmosphere.


Comment: Somewhat prepared (Score 3, Interesting) 191

by AaronW (#47743585) Attached to: Slashdot Asks: How Prepared Are You For an Earthquake?

All of my bookshelves are strapped to the wall. My hot water heater has three straps (only 2 are required). Emergency rations are available plus I have my camping equipment and propane for my stove. Next to my bed I have an emergency radio that charges via USB, solar or a hand crank. I'm not terribly concerned about water though I keep several gallons of bottled water. I have a water purification system for camping but the main water supply is literally two blocks away from me though it's on the other side of the Hayward Fault. They just retrofitted the water pipes crossing the fault a few months ago right near my house. In an emergency there's always 50 gallons in my hot water tank. I also have a wrench handy for turning off the water and gas. I'm more worried about gas, especially given that we're supplied by PG&E. It took many years of complaining by my parents until they fixed a rather sizeable gas leak under their property. The only thing I'm missing is a generator.

I imagine I'll have a lot of stuff falling off of my shelves making a huge mess.

My house is only a few hundred feet from the Hayward fault. The fault goes right through one of the nearby apartment buildings. Many years ago the developers would conveniently relocate the fault to suit them. Our old city hall which was built on stilts was built on top of a mound that was pushed up between two traces of the Hayward Fault.

My house is bolted to its foundation and is only a single story so it will probably be OK though I might have some damage from my chimney. I also have earthquake insurance though it's quite expensive (around $4K/year).

Comment: Re:Meh. the time limit is still there (Score 1) 174

by AaronW (#47685485) Attached to: Tesla Removes Mileage Limits On Drive Unit Warranty Program

The superchargers are not subsidized in any way by taxes. The cost of the electricity used is factored in to the price of the car itself for the 85KWh battery or is a $2000 option for the 60KWh battery car. The actual cost of the electricity is not much. If Tesla is paying $0.10/KWh then a full charge is $8.50. $2000 would cover a lot of charges. Since most charging is done at home overnight it ends up not costing Tesla much money at all. As they build out their solar the cost of the electricity drops even further. Tesla also paid back, with interest, their government loan. The $80K cars are being used to fund their development of $30K cars.

Tesla has agreements with the property owners for installing their superchargers in their parking lots and it's often in the property owner's interest since that means that someone with an expensive car will be stopping by there for half an hour or so to charge and will likely want to use the amenities in the area. Public funds are not used in any way.

Comment: Re:Meh. the time limit is still there (Score 1) 174

by AaronW (#47685453) Attached to: Tesla Removes Mileage Limits On Drive Unit Warranty Program

Currently there are far more superchargers than hydrogen filling stations and they are expanding very rapidly. On top of that, there are tens of thousands of public charging stations at shopping centers, parking garages and elsewhere. Electricity is everywhere. A supercharger is estimated to cost under $200K. A hydrogen filling station cost a minimum of between 2 to 4 million to build and the cost of hydrogen will never be competitive with gasoline, especially if made from cracking water water.

The cost of a battery swapping station is still far less than the cost of a hydrogen filling station. Most of the time the only thing that is needed for the battery swap is electricity and periodic restocking of batteries, which may not be all that often since the cost of swapping includes swapping again for your original battery. For one thing, the hydrogen filling station will need to be manned when it's open for safety, the battery swap does not need that since it is fully automated. Second of all, the cost of a hydrogen filling station will be far higher. If hydrogen is not made on site then a LOT of trucks will be needed to transport the hydrogen since a truck can typically only carry enough hydrogen to fill around 200 vehicles due to the heavy high pressure tanks involved. Regular pipelines cannot transport hydrogen due to embrittlement and leaks. High pressure pumps are also required. The equipment to make hydrogen on-site is also very expensive, and if it is made from water then a tremendous amount of electricity is required. Most likely it would be made from natural gas through steam reforming which also releases CO2. It takes several times as much electricity to make hydrogen to power a single hydrogen fuel cell car as it does to power an EV. In fact, 20% of hydrogen's energy content is used just to compress it.

Furthermore, you will need far more filling stations since EVs typically do most of their charging at home. With hydrogen this is not really possible. The only time I need to use a supercharger is during long trips. I have no need for most of my driving which is within the range of the battery. I spend 5 seconds plugging in at night and 5 seconds unplugging in the morning. Superchargers are typically needed along long distance routes, not in every town like gas stations or hydrogen filling stations.

Comment: Re:Meh. the time limit is still there (Score 3, Interesting) 174

by AaronW (#47683559) Attached to: Tesla Removes Mileage Limits On Drive Unit Warranty Program

I see superchargers popping up all over the place. They're becoming quite common along the east and west coasts. They're not needed for in-town driving since most people charge at home. The battery swap will cost about the same as a full tank of gas and includes swapping your original fully-charged battery back on the return trip. Using the supercharger is free forever.

I've used the superchargers numerous times and they were not a major inconvenience. When I drove up to Lake Tahoe from the Bay Area I stopped at the one in Folsom. I went and grabbed a burger and by the time I was done eating and using the restroom the car was ready to go and it cost me nothing to use.

Every morning I start out with a full battery. It takes me 5 seconds to plug in at night and 5 to unplug in the morning. I spend far less time charging than I ever did waiting in line to fill up with gas at Costco. Besides, I don't have to stay with the car while it's charging. Usually there's other stuff to do within easy walking distance. In 30 minutes I get 170 miles of range. They're generally only needed on long trips, not for everyday driving since it's more convenient to charge overnight at home. Even charging at home I average over 50 miles of range per hour of charging (with a dedicated 80A 240V charger).

The chargers are popping up all over the place as can be seen on Tesla's interactive map:

Better Place died because nobody wanted the EVs that they worked with. Their range was also quite limited and the Better Place setup was quite expensive. With the Tesla I have a choice. I can pay to fill up in 90 seconds or spend nothing and wait a while.

My last electricity bill for around 1500 miles of driving was $62.57 for 39 days, and I'll admit I tend to exceed the speed limit and accelerate hard, so I'm not taking it easy either. Next month I'm driving up to Seattle and it will cost me $0 in electricity.

Comment: Re:To make it clear (Score 4, Informative) 174

by AaronW (#47683533) Attached to: Tesla Removes Mileage Limits On Drive Unit Warranty Program

The drive unit is a combination of the single electric motor, gear reduction, differential and inverter and axles. It's all a single unit that can be quickly replaced. As Elon stated in his last earnings call, most of the problems were due to some cables that were tucked up in there coming loose and making noise. Before finding out that that was the root cause they just replaced the drive unit because it could be done quickly. Now it turns out all they do is apply some zip ties to fix the problem. The car is fairly modular and should be fairly easy to work on, especially since there's no engine in the way of everything. Things like power steering, coolant pumps, AC, etc. are all easily accessible after removing the frunk plastic tub or the plastic panel under the front of the car.

When I have taken my Tesla in for a problem they don't fool around but try to address it as quickly as possible. All of the issues I've had with my car, an early model S, have been addressed by later versions of the car.

Here's a picture of the drive unit:

New systems generate new problems.