performance Definition and 240 Threads

  1. N

    Java Comparing Python and Java: Performance & Standard Libs

    Any one have any opinions on the differences between these two language (and their closeness to C)... chroot posted about python being almost as complete as java interms of standard libs. I attended a presentation which seemed to verify that claim though you have to download some of the added...
  2. Cyrus

    Introducing My New Road Bike: Performance & Speed!

    After waiting a week and a half she's here! http://photos-004.ak.facebook.com/photos-ak-sf2p/v78/133/69/5736845/n5736845_34678004_5514.jpg http://photos-005.ak.facebook.com/photos-ak-sf2p/v78/133/69/5736845/n5736845_34678005_5782.jpg Oh yeah, its Ultegra components...
  3. B

    Sun Sensor Performance in Earth's Shadow

    Hi, Will a sun sensor work if the satellite is in the Earth's shadow? thanks!
  4. L

    Debate: Pressure vs Force in Water Gun Performance

    [SOLVED] Water guns Currently on a forum about water guns there is a debate going on about what determines a water gun's performance between pressure and force. On one side are people who say that higher pressure differentials combined with a higher "Cv value" will mean more flow, which...
  5. A

    Aerodynamic performance of a double shrouded fan

    Hai I am using a double shroud fan wheel for our application. what will be happened, if i use the same dimensions fan wheel with single shroud ?. can u clariffy for the same in the following points. 1. Discharge 2. Total Head or static head or Dynamic head 3. Power With regards...
  6. M

    Question about performance (computers), does this make sense?

    Hello everyone we were given this question to think about, and I wans't sure if my reasoning was right or not, what are your thoughts? #1. It is obvious that using more hardware results in better performance, but that the performance increase is not linear in the amount of hardware added...
  7. L

    How temperature affects GM tube performance?

    Anyone familiar with GM tube, please share some experience on the effect of temperature to GM tube performance, how does it influence? I found our GM tube tally has increase a little as the temperature increased rapidly from 4 degree to 55 degree, I wonder is it a casualness or a indication of...
  8. R

    Heat pumps and coeffiecent of performance

    Hi everyone, I was hoping to ask a thermodynamics problem, specificially one about heat pumps and coeffiecent of performance. I am wondering if I am missing something. I am given that heat pump is heat a building. Inside temperature is to be maintained at 22 degree celcius, outside is...
  9. H

    Car Brake Performance Using Disc-Brake Variations

    Hi all, Im a Mech Eng student getting my 3rd year project underway, Using a simple ABS Disc Brake system model, i would like to analyse braking performance for calculations obtained with variations of brake pad size, mateial, and also different disc sizes and materials. My question...
  10. 5

    Can it hurt an engine's performance by having to big of a throttle body?

    It is always a big debate on mustang sites on whether a big X throttle body is not needed or that it will not hurt anything as far as the performance goes. Some say, "too much air can't hurt." Some say, "too much air can hurt."... Which one is it?
  11. 5

    OT: Looking for good book on performance engines (ICE), trying to learn

    Well I have always been interested in engines and how to make them more efficient and make more power. Particularly the popular modifying of Ford and GM engines (302ci, 351ci, 350ci, etc.). I am looking for a book that could help me understand how a cam actually works, and what to tweak...
  12. K

    Carnot Refrigerator coefficient of performance

    A Carnot refrigerator operating between -10.0 C and 40.0 C extracts heat from the cold reservoir at the rate 300 J/s. What are (a) the coefficient of performance of this refrigerator, (b) the rate at which work is done on the refrigerator and (c) the rate at which heat is exhausted to the hot...
  13. J

    How does motor slipage affect fan performance with a VFD?

    Im a HVAC contractor/designer. I am looking to install a fan unit with a VFD. This is 3 phase, 60HZ, 460 volts, 40HP AC motor. Im trying to create a "system curve" like a fan curve that would show the cfms at various frequency settings being changed by the VFD. I can reiterate or...
  14. K

    Maximize Mousetrap Car Performance for Physics Project

    I need to build a mousetrap car for a physics class and i was wondering if anyone could possibly give me any ideas on how to make the car travel faster and further. The requirements are that it needs to travel 25 ft for an A while carrying a full (closed) can of pop.Also, we can't use anything...
  15. S

    How Does Heat Pump Performance Vary Between Northern and Southern Climates?

    1. North vs. South. A heat pump is designed for southern climates extracts heat from the outside air, and delivers air at 20C to the inside of the houses. What is the average coefficent of performance of the heat pump: (Consider this to be a Carnot device) a) In the south where the average...
  16. B

    Wind Turbine Blades and Wind Speed Performance

    I wonder if anyone could shed some light or information about the subject I'm looking into. How will wind turbines with varied amounts of blades perform in varied wind speeds. E.g. the less amount of blades you have the better a turbine will perform at higher wind speeds? Any help on the...
  17. Cyrus

    MATLAB Matlab program to montior the motor performance

    I am considering writing a MATLAB program to montior the motor performance of my model airplane. I would have to do it through USB, because I only have one 232 port, so I can't use multiple devices from that one port. I would like to montior the temperature, voltage, current, power, static...
  18. C

    Magnetic Compass Needle: Remanence & Airgap Effects on AC Performance

    1)does a magnetic compass needle have high remanence or low remanence? 2)in a shell type transformer core required to carry DC in addition to normal AC, what effect does the introduction of an airgap have on AC performance of such transformers.
  19. ranger

    What those words on yearly performance review realy mean

    Every wonder what your boss is really trying to tell on his yearly performace review...
  20. S

    Analysis of Performance of Rotary Vane Compressor

    Hello all. I have the following questions regarding the analysis of the performance of a rotary vane compressor. 1) Why can the specific kinetic and potential energy changes normally be neglected? 2) If an adiabatic compression is considered, what is the primary cause of energy loss...
  21. N

    STL, in large systems sims/high computing performance

    (hehe here's another one for you dduardo :biggrin: ) Does anyone know if STL is used or is capable of being used in large system simulations? Or is it best to write your own datastructtures? Looking to do some computational astrophysics or large neural nets and am not sure whether to use STL...
  22. L

    Conquering Exam Anxiety: Tips for Optimal Performance

    I had a midterm today, and I think I did bad on it even though I studied hard for it. When I first glanced at the paper, I knew how to every problem. But when I started to each problem, my neck started to go stiff, and I couldn't think properly. It seems as if though everything I studied...
  23. J

    Optimizing Modem Performance: Understanding Communication Parameters

    Why are communication parameters important when a computer uses a modem? Thank you in advance
  24. R

    Lingusitics Relationship between Asiatic language and science/math performance?

    In the states there is a positive stereotype about the high performance of Asian students academically, particularly in the maths and sciences. I have heard there is a study of american students that showed asians scoring an average of 10 points higher IQ than other groups, but this is...
  25. R

    Overcoming Poor Undergraduate Performance to Pursue Math PHD

    I'm now a programmer in a Shanghai based IT company. I have been graduated from college for 4 years and my major in college is not math or physics related. But I kept thinking my "philosophical stuff" along and recently found there's answers for me in both pure mathematics and theoretical...
  26. W

    Einstein Cycle: Analysis of Low Temperature Refrigeration Performance

    I'm sure most of you have heard of the Einstein Referigeration Cycle . For those who have not I've listed the references for further reading.. http://www.me.gatech.edu/energy/pubs/SLA_2.pdf ok 342 K is about 156 F ,for anyone with an attic , it seems to me that this is the perfect solution to...
  27. ohwilleke

    Aluminum Wire Performance: Advantages & Disadvantages

    Does an aluminum wire have any performance disadvantages other than having to be thicker to carry the same amount of current?
  28. A

    What Is the Coefficient of Performance of a Carnot Heat Pump?

    This question is killing me because I just can't seem to get it. A heat pump is used to heat a house in winter; the inside radiators are at T_h and the outside heat exchanger is at T_c. If it is a perfect (e.g., Carnot cycle) heat pump, what is K_pump, its coefficient of performance? Give...
  29. N

    3 Volt DC Motor Performance Graphs

    Does anyone know where I can find 3 Volt DC Motor Performance Graphs on the web? I'm looking for something like this, but with a 3 Volt motor. My googling has yet to find any relevant results. Thanks in advance.
  30. H

    Maximizing Heat Engine Efficiency: How to Find the Optimum Performance

    how can I find efficiency of heat engine operating between two differenct temperatures?
  31. M

    Factors Affecting Ribbon Cable Performance

    Can someone give me some examples of factors that affect the performance of ribbon cable please.
  32. X

    Setting Quality Targets: Analyzing Call Centre Performance

    Hi, This is not a physics question. However, I was hoping someone could help me. A call centre sets a quality target of answering the telephone within 30 seconds. The results of monitoring show a normal distribution with an average answer time of 28 seconds and a standard deviation of 2...
  33. D

    SNL Season Premiere - Ashlee Simpson's Flop Performance

    Did any of you see Saturday Night Live's season premier? :biggrin: You've probably already heard about Ashlee Simpson being exposed for the talentless fraud that she is. SNL is known for great, live musical performances, but Simpson is probably its biggest screw-up ever. Instead of...
  34. enigma

    Airfoil moment performance details

    I'm looking for either tables or graphs which show variations in moment coefficient (either about the 1/4 chord or the leading edge) as angle of attack changes. I have details for a handful of NACA standard airfoils from Anderson's Intro to Flight book, but I'm looking for more. Most of...
  35. H

    C/C++ Program Performance: Validating Entries & Measuring Processing Power

    I,m writting code in C/C++ and when i validate my enteries(ensure they are numeric) i use !cin.good(). Also how do i clear the buffer after an invalid entry? I usually use cin.seekg(0);cin.clear(); How do they work? Is there a better way? How do i find out how much processing power and...
  36. S

    Computer Troubleshooting: Emergency Shut Down and Slow Performance

    Hey guys, last night my computer was fine until a game froze but since it was about 2:00 AM i just did an emergency shut down and went to bed. Anyways today when i put my computer on it moved painlessly slow. When I try to use the internet it says not responding, almost none of my programs can...
  37. M

    Increasing Performance in F1 Cars | Max

    Hi, I am new to this site and i have a question that has been making me thinking for ages, what factors other than different grades of fuel and oil in F1 engines increase the power, because i have found that say Honda or BAR are down on BMW and Ferrari in terms of power by up to 100HP. Thanks Max
  38. Dissident Dan

    C/C++ Performance: OO vs Procedural (C++ vs C)

    I'm wondering what the performance differences are between using C and C++. I think that it's quite clear that large C programs will generally run faster that large C++ programs, but how much so, and what factors have what effect? For example: I would assume minimal or no effect in the...
  39. M

    Coolant Systems For Armor Design: Efficiency & Performance

    i am designing an armor in my head (along with hundreds of other things) and i want to know specifics about cooling systems. I've decided on a coolant system pumped by feet/arm movements/etc but i need to know: how effective are such systems? specifically, how long would they last, how cold can...
  40. A

    Unlock the Solution to Score Player Performance in Team Game

    Hi all, this may seem a bit martial or militaristic, but remember it's just a model for a mathematical process that I'm interested in. OK. Imagine you have a game (or fight) where 2 teams oppose each other. The exact nature of the game is not important. However, the game has several rounds...
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