Computer Science

I have a question about the functioning of 2PL and deadlocks. I'm not sure why this is so difficult for me to grasp, but I tried drawing a pseudo sequence diagram to help. Is my understanding of 2PL correct? I am aware that deadlock handling is not exclusive to 2PL. Is it accurate that if T1 acquires a writelock (exclusive) and T2 tries to acquire a readlock, T2 is obliged to wait? I realise that only one transaction may have a writelock, however according to 2PL, if a transaction is updating (has the writelock), another transaction cannot read (acquire the readlock). Looking forward

First, does a computer chip require an atmosphere to run? In other words, it can run in a vacuum, right? Second, I know there is an upper limit to acceptable temperatures for chips to run correctly in (hence heatsincs and fans in computers), but is there a lower limit?

Hello, I have been looking into both 2.4Ghz mice and normal standard wireless mice. I am not really sure on what the advantages are for each one. I know that 2.4Ghz is more expensive than normal ? But what are the advantages ? Is it true that they work from a further distance than normal wireless mice ? Anyone got any advice ? Thanks !

This seems like a genuinely stupid idea to me, but I can't help but pose the question: could an algorithm be written to beat the game 2048? Remember, computer science is definitely not my area of expertise, so try not to be too hard on the n00b.

3-Sat is basically a Boolean expression written as an and of 3 or statements. (a!bc) and (!a!bc) and (!ab!c) and (!cde) and (!bc!d) 010**** 110**** 101**** **100** *010*** (aaa) and (!a!a!a) 0******* 1******* It can be solved in deterministic polynomial time by performing a bitwise unique match on FALSE values stored in an array. For example (a or !b or c) is only false for (010). We add the false values to an ordered array so a,b,c etc and simply do a bitwise check to see if the opposite already exists in the array, so for 010 that would be 101. If the opposite already exists then the Boolean expression is unsatisfiable. This would need to it…

check this out! http://news.bbc.co.uk/1/hi/sci/tech/8060082.stm

Quick question. I'm trying to make a 3D array in the sort of: array( 1 => (1, 1), 2 => (1, 1) ); type of way. I inductively assumed the following would work but I get a "parse error, unexpected T_DOUBLE_ARROW": <?php $tt = array( 1 => (1 => (0, 0, 0), 2 => (0, 0, 0), 3 => (0, 0, 0)), 2 => (1 => (0, 0, 0), 2 => (0, 0, 0), 3 => (0, 0, 0)), 3 => (1 => (0, 0, 0), 2 => (0, 0, 0), 3 => (0, 0, 0)) ); ?> So obviously the above is wrong but my good friend google doesn't seem to have a better way. So, anybody know how? (This is going to be my filing system for a new game I'm working on: [x][y][info])

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I have learned 3D studio max at school, but I can't find a Mac version of 3D studio max.... Any one knows where to obtain a mac version? or if not possible, any equivalent mac software to 3D studio max? thx for furthur responds Albert

does anyone here use this technology in their laptop or know anyone, and what in your opinion is the best deal? and roughly how does it work? I`m thinking of getting Anywhere Internet for my laptop, and am looking at either PCMCIA cards or a USB dongle to do this with, I`m leaning towards the PCMCIA as there`s little in way of sticky-outy bits that can break off. as far as I can tell the card works like a modem using most of the Active bits found inside a mobile phone, and you need to stick a SIM card in it. beyond that I`m totally lost:confused: anyone?

So I have been having some fun messing around with the 3x+1 problem, also called the Collatz Conjecture. What I have been able to do is create a program in Python that given an integer will print each step of function until it becomes 1. The code I wrote for this was: from __future__ import division from visual import * from visual.graph import * n= while n!=1: if n%2==0: n=n/2 if n%2!=0 and n!=1: n=3*n+1 print n What I would like to do is to modify this so that I can have the program run for a large number of numbers, and return the number of steps it took to get to 1 for each number. Sadly I really have no idea how to approach …

What sort of speeds could you get out of a computer that somehow used 4D calculations as a sort of "thinking space" to become more efficient?

This bit taken from another thread, gave me this idea. I've heard these analogies before, but never with a comparison to computer games. So my question now is, how hard would it be to have a non-euclidian game universe? Say, a first person shooter with 3 space dimensions, 1 time dimension, and a closed space-time? Would people get the hang of warped space? Or would they get incredibly annoyed? Could one of the physics/graphics engines be modified for this purpose or would you have to start from scratch? Would graphics cards be useless for this?

Please see full BBC article here...http://news.bbc.co.uk/1/hi/technology/7044606.stm

http://news.bbc.co.uk/2/hi/technology/2822333.stm What a connnection! lol

Hi all, I have a question. It's regarding chess software. The strongest playing chess playing chess program currently is Rybka 3 developed by Vasik Rajlich. Now there are two compiles of Rybka: there is a 32 version for 32 bit Windows and a 64 bit version for 64 bit Windows. I realized that the 64 bit version playes quite stronger than the 32 bit version. What is the reason for this? Why does the 64 bit version play much stronger?

This thought came across my head recently. All of the processor vendors are starting to show off their 64-Bit CPU's for home & business use. My question is, does anyone know if the original x86 compilers will compile efficient code on the new 64-Bit processor? Most claim to be native to x86 as well as their new instruction set, but some (Itanium & Itanium2) claim to simply "emulate" the 32-bit enviroment, which would mean that just about all compilers will produce inefficient, crappy code on them. If Intel plans on dominating the server market, and the servers are running older x86-oriented software (Apache, Linux, etc), then will the processor even add po…

// 64-bit random number generator. // CODE DELETED }

OK, so I've got a bunch of speakers lying around so I thought I'd make a home made "surround sound"... the reason I use "" is because it's not technically true surround sound as I'm using the standard stereo port on my computer, but I'm feeding that signal into a tiny breadboard to which I can attach lots of speakers, the end result is that I've got 7 speakers operating on two channels (standard left/right stereo). My only thing is, I now have 7 speakers drawing current from 1 port which is meant to supply 2 speakers, could this put a high, potentialy damaging, drain on the port/computer? Actually the comp can handle it, looking at PSU supply/current useage but co…

As the title implies, I need a way to compute a huge number of permutation fast, you can test it in this calculator. The order and repetition doesn't matter so choose no for both. Now the thing is since the number is so big, it would be store inside an array of number. And I've done that much, but to computer the number requires 800000000 iteration, and it takes a long time. I saw that Python has a script call npr that can computer it really fast. I want to know if there is a way to do it for c#. In other words, I want to compute 8000000000! / ((4000000000!)(8000000000-4000000000)!) Let me know if there is any lead in this one, I would like to know if there is a w…

Aights so this is the problem. I need to know everything there is to know about maple 9.5. Please enlighten me. If you need somewhere to start how do I graph a function. step by step please. Any help appreciated.

Recently purchased some. Windows however does not seem to recognise that they are what they are, it says that the disk capacity is 702mb and WMP still says, in burning mode only 80 mins free, anybody else had the same problem?

I am trying to achieve a box like this using the 960 Grid System, my only issue is how to get the headings on the side of the box. Any code/ideas would be fabulous! Thanks, Dan

Hi guys, got a small issue. I'm developing a site and I'm using the 960 Grid System, which is great everything should mathematically be alligned. I've got this problem as you can see above the social networking bar extends outside of the grid system. I've increased the padding on the links as a test just to see if was the links but it seems to be the division/div itself. Here's some source code, HTML: <div id="secondnavbar" class="grid_12"> <!--AS YOU CAN SEE ITS SET AT grid_12 SO I'M STUMPED--> <p class="navpar"> Social Media: <a href="http://www.facebook.com/aberguild" class="facebook"> FACEBOO…

From what I'll reasonably guess, computer languages and implementation decisions have evolved sort of ad-hoc, which if true is one reason for the difficulty level of mastering computers. Another element, I'd suppose, is the loss of any paths that could've a) streamlined design, b) focused more on best practices, and/or c) increased overall efficiency. To elaborate, such a path can be any worthwhile fork in the past's road of computer developments that for a reason got abandoned/neglected/overlooked (for a less effective one?). If we add up all such instances of lost paths, those might be enough, potentially, to compound the overall level of complexity creep* in today…