performance Definition and 240 Threads

Hello, In Fortran 90, will the performance (in terms of computational efficiency) of the following two be the same. If not, which one will be faster. Please advise with the reasoning: (i) do i = imin,imax do j = jmin,jmax do k = kmin,kmax Several statements (rigorous...

I was wondering, are there significant effects on the performance of a solenoid when the solenoid is inside an external magnetic field? Does it affect the rate at which the magnetic field is established within the solenoid?

Homework Statement Okay, so in my Physics 2(high school) class the instructor gave us a lab without any instructions whatsoever even though we have only been covering electricity for 2 days. The question he posed to us was "What factors affect a battery's performance?" and we have to write up...

what equation would i use to find the max velocity and max alt of a rocket. the probem gave me mass of rocket (g), mass of engine (g), mass of propellant (g), average thrust of engine(Newtons), burn duration of the engine (seconds). i got an example which is massrocket=23,mass...

How can we predict the actual test performance of pump from CFD. I need some formulation/calculation method to predict closure.

I got a small 16inch folding bike weight 13kgs and managed to shed it down to 9kg and working in weight reduction further... eg using hollow shaft at the peddle and using clips at the axles and replacing to 14inch rims and redoing the frame in lighter stainless 201 - these are my next to-do...

I recently got my first job after graduating with a BSME and was upset with my evaluation I received. This is a very small company and I was the first truly entry level person that they hired. I am upset because I was trying so hard, but no matter what, it seemed like I was making the wrong...

I am contemplating a new PC build, but I feel that since I am so neurotic about details, it is not going to happen for quite some time. I need to put a lot more research into it. But for the time being, I would like to maximize the performance I get out of my old Dell dimension. The specs right...

Dear twofish-quant, I found this thread interesting especially since I have a daughter in college, and have friend's whose kids are in the same situation. During a discussion with one of them about achievement, grades, stress, time management, cramming, all nighters, etc... I asked him...

Let's say you have a turbojet shaft that needs sealed. Temperatures and pressures are very high (very). Now let's assume that you don't know squat about seals. Aside from brush and labby seals, what other sealing options exist that can operate at extremely high pressures/temperatures (and...

Hello, I am a tactical driving instructor and a precision/stunt driver. For more than 15 years I use high PSI tire inflation method on my family car, tactical training courses or stunt performance cars. Namely, if on the side wall of the tire manufacturer is indicating that maximum PSI 41...

I am attempting to build an intake setup for an engine I'm working on. I currently have a 3" diameter aluminum pipe on the throttle body that just curves off to the side. I would like to try and get some cooler air by routing it down into the bumper. I have access to 2.5" diameter piping. I was...

If I have a designed gear box that needs a motor to run , and according to my calculations the input power for the gear box must be 10 Kw at 10 r.p.s must I chose a motor with the same input specifications ? when I buy a motorwith certain specifications like : 10 kw 3000 R.P.M , does these...

A contractor furnished a performance bond having a face value of $100,000 and a payment bond of $100,000. The contract price was a lump sum of $1,000,000. The contractor had completed 60 percent of the work and had been paid $540,000 by the owner. Then the contractor defaulted, leaving unpaid...

I'm just starting to use MPI in Fortran90 and have some questions on improving performance. At the start of a calculation, I run a stage to distribute all required data to the slave nodes. This is a one-off step, but seems to be taking a long time. The code running on the master node...

I'm still reading the paper, but this appears to be a http://arxiv.org/abs/0906.0022" on the students' response to two different curricula on teaching intro E&M at the undergraduate level. They did this at 4 different well-known universities in the US and arrive at a rather conclusive and clear...

01.http://img2.orkut.com/images/milieu/1/1213787033773/32174292/pt/Zpog0ya.jpg How to post image here Its our rc car driven by 3.2 hpi engine 2 speed transmission system, bell crank steering mechanism , fuel use nitro+mthnol its a two stroke engine two wheel drive question:how to increase...

Hi, I am using Sensored BLDC motors for some robotic movements. I am driving my motors using motor drivers. I am using ball screw mechanism for lifting a pedal up and down. On the pedal, there will be always a very high load, placed on it. Now, my motor can lift up the pedal with my desired...

The problem is: Compare the performance of the forward, backward, and central difference methods for estimating the derivative of the following function: y(x)=e^-xsin(3x). Use 101 points from x = 0 to x = 4. Use a random additive error of +/- 0.01. I understand the process of solving this...

Hi guys, great forum you have here... basically, a couple of years ago, I've gotten involved in the hobby of watercooling computers by adding a radiator, pump and waterblocks on the cpus and other heat sources. well, as I've been researching builds by other folks, i notice that some...

hi, is there a reason that powerpc and itanium have been unable to outperform the x86? apple had the g3, g4, g5 and at times claimed powerpc and risc outforms the pentium, and intel itself bet that itanium epic would outperform the x86, and have lower power consumption and replace the x86...

I finished my co-op this past Feb after working at a major technology company (think Intel, AMD, IBM, HP, etc) in a pretty specialized field. For my end of term student performance report, I received quite a good response from my manager. In all the competency categories, I received an...

Hello, I have 2 24V lead acid batteries in parallel to make a power supply for my circuit. I want to do some drain tests, and plot a curve for % energy remaining vs. time. The load on the battery isn't that large, and I don't want to have to supervise my experiment for 12 hours solid. Im...

PROBLEM 1 (work done by gas) Homework Statement 1. An ideal monatomic gas originally in state A is taken reversibly to state B along the straight-line path shown in the pressure-volume graph. What ist he work done by the gas? A) +12 cal B) +122 cal C) 0 cal D) -110 cal E) +110 cal...

Efficiency is essentially the ratio of what you get to what you put in. COP also seems to represents the same thing (i.e. COP of a refrigerator is Ql / W, which is the amount of heat removed / the amount of work done to remove it). I know efficiency cannot exceed 1, but how come COP can have...

Homework Statement I need to find out the rockets max velocity and max altitude. My teacher gave us an example but everytime i use the stuff we know his answer doesn't match mine. So we know: Rockets mass=23 grams mass of engine=16.2 grams mass of propellant=3.12 average thrust=8 Newtons burn...

What is an optimal CO2 concentration (a range of values or percentages) for maintaining baseline performance among humans? For example, short term exposure to CO2 concentrations less than 5% has negligible impacts on performance (I don't think this is true, it's just an example). If anyone...

Hi. I am designing an experiment focused on radio waves for my experiment and this is the basis of it: Three antenna's will be tested for point to point transmission (VHF): [ 144 MHz ] >>3/4 Wave antenna >>1/4 Wave antenna >>5/8 Antenna (Best Angle of Radiation Usually) These...

i have just finished my undergrad in physics with dismal scores. i really wanted to study physics. i found it exciting and still do. but exams are a real hardle for me. i just have a phobia for them. now i am entering my grad school and for the first time after starting physics i am doubting my...

Lightness and Trouble describe current thinking about the most fundamental physics questions--the underlying nature of space and matter. Ten years ago such books might well have emphasized string efforts in that direction. These books do not. They are in that sense post-string popular accounts...

Hi fellows; we used the gas turbine from solar inc. A catterpillar company model centaur 4502 and 4702.i am resposible for the test cell where the gas turbines engine tests after over hauling.i face some problems.our engines are two shaft the power turbine direct couple with the dynmometer.the...

What are the variables that influence the performance of an internal combustion engine?

Hi, I was trying to analyze the performance of a so called expert stock picker. Can you please check my argument? Are there any holes in my argument? According to the stock picker, out of 15 stocks he picked over his career 10 turned out to be big winners. I made the following argument...

Can someone please explain to me what "Performance Factor" is? I wasn't sure where to post this, but as the title implies I need someone to explain to me what the concept of "performance factor" is. I'm not sure if that's the correct english phrase I'm looking for, but that's how my dictionary...

how can i get greater performance from an standard inverter duty motor( marathon black max). I am in the process of buiding an inverter/controller to use as part of an EV conversion.

This O2 Maximum Performance product is an energy enhancer. It's a bottle where you puff in 92% oxygen. I think most people would agree more oxygen = more energy, but I wonder how much just a few puffs will do for you. The bottle servings per container is about 60 puffs at $20. Most times...

Hi all, I have been thinking about an interesting concept. I have the laptop version of the 7800go and I know that most programs don't support laptop versions of GPU and hence most programs use them inefficiently and this results in poor performance. I have come up with a few solution...

Hi guys, Now I want to build a computer for intensive calculation. I am expecting to spend somewhere 4000 dollars just for machine. The only thing I must need is nvidia video card. hhd size isn't important but the speed is. Do you guys have any suggestion?

I need to perform standard set theory operations such as union, intersection, difference on sets of integer numbers. Each set can have a few hundred elements and each operation can involve a few hundred sets. The operations can easily be written in Java using the Java Collections Framework...

How come processors run faster under cold conditions and slower under hot conditions? I always assumed resitance would play an important part in this and if a processor is made up of some type of semiconductor then resistance would decrease with temperature thus allowing more current to flow...

How do low grades (say, Cs or lower) in general education courses affect graduate school admissions? In my case, I'm a pure mathematics major who is failing honors microeconomics. I just absolutely loathe the subject. How is this going to affect my future? Will they care, or just look at my...

Hello all, We would like to build a system in order to evaluate the performance of air-conditioning. Who can help us to disign this system or introduce the company where we can consult? thank you! Pham Vinh

can anybody help me with this question? A 10 stage instruction pipeline runs at a clock rate of 1GHz. The data forwarding scheme and the instruction mix are such that for 15% of instructions one bubble, for 10% two bubbles, and for 5% four bubbles must be inserted in the pipelin. The...

For those who don't know, I'm an HVAC engineer. From time to time, the issue of heat pump efficiency comes up. When picking a system, obviously efficiency (cost) is important, so we need to decide between, usually, heat pumps (air source) and gas for a small split system. The government has a...

Greetings all! There is a bit of a debate in the world of mountain bikes, concerning the conventional 26" wheel diameter versus the rising popularity of the 29" wheel size (nominal diameters). One of the popular beliefs is that the 29" wheel requires a larger brake rotor than a 26" wheel...

Just a couple of weeks ago, my laptop started making a very loud roaring noise and experienced a severe slowdown in performance (programs and windows open very slowly) at the same time. It takes a couple minutes after booting up for the noise to begin, but once it starts it is continuous. At...

Biologically, what does it do to provide more energy?

Questions come up time to time regarding stainless steels and special or high performance alloys. Manufacturers and suppliers have some technical information on their websites. For example, here are some major suppliers: High Performance Alloys, Inc. http://www.hpalloy.com/Alloys/...

Hi, I wanted to make an equation with Newtonian physics, but failed. Here's the problem: Consider an object with that ^ has m mass, and a built in drag & | magic motor that has P friction...

So I know that my CPU is now slowing down, even though Process Explorer reports system usage as varying between 30-70%, far short of 100% system usage. What is the most reliable way to measure system usage before the system starts to slow down?