Systems Definition and 1000 Threads

A system is a group of interacting or interrelated elements that act according to a set of rules to form a unified whole. A system, surrounded and influenced by its environment, is described by its boundaries, structure and purpose and expressed in its functioning. Systems are the subjects of study of systems theory.

View More On Wikipedia.org
Recent contents Top users
  1. T

    How do I solve a circuit with multiple nodes and loops?

    Homework Statement In attatchment Homework Equations Not sure How to come up with the other equations. The Attempt at a Solution Assuming a node is an element connected to two or more elements. 1) Moving clockwise from V i1 to i2. Node one is between the negative side of the...
  2. G

    Electrical Engineering - Control Systems - Design Via Frequency Respon

    done editing Homework Statement I'm given the following transfer function that represents a physical apparatus G(s) = \frac{X(s)}{F(s)} = \frac{3.333*10^{4}}{s^{2}} I'm asked to design a lead compensator to achieve closed-loop stability. The requirements are that it must have a transient...
  3. D

    Why do bound systems have less rest mass than the sum of its parts?

    Hi PF. This a fact well aware to just about anyone that has had even basic chemistry, but I'm having a hard time coming to an understanding as to why this must be true. So why? Also, if I knew that some box contained, say, a proton and an electron, could I ever know whether or not, inside...
  4. timthereaper

    What is the difference between digital controls and digital control systems?

    "Digital" Control Systems I recently took a control theory class at my local university and we learned about PID, loopshaping, and state-space methods and implemented them in MATLAB/Simulink and used an Arduino for some projects. However, I was talking with some EEs (I'm an ME) and they were...
  5. J

    Control systems design software

    Are there any software programs for purchase that allow control system modeling and design for individual use under $1000
  6. B

    Two force systems have the same resultant

    Homework Statement Attached image. Homework Equations Cosine rule |F| = √(Fx2 + Fy2) The Attempt at a Solution I tried to calculate the force components in the x and y direction for both and got two expressions for R (one from each system) and made them equal each other...
  7. X

    Control Systems - Root Locus with proportional control

    Homework Statement Homework Equations See below The Attempt at a Solution Root Locus? Easy Peasy right? Based on provided equation G(s), i solved the coordinates of the root locus diagram using quadratic equation. For the 2nd part of the question, i have to find gain at which rise time...
  8. X

    Control Systems - stability and settling time

    Homework Statement Given G(s) = 1/[(s^2+s+4)(s+6)] and C(s) = k, find the limit of stability of k. Also, what is the range of k such that the settling time is between 10 and 20 seconds. Homework Equations Provided above The Attempt at a Solution I have attempted to set this...
  9. 2

    Controlled systems - Closed loops

    1. Homework Statement [/b] http://snag.gy/m9Iq0.jpg Homework Equations The Attempt at a Solution I know that the sensistivity of a closed for at small change is given by the formula S = ∂ Ln T/∂ Ln G And T(s) = G_c(s)G(s)/1 + G_c(s)G(s) But since i don't have any G_c(s), i...
  10. A

    Single Degree-of-Freedom Systems

    An SDOF system (m = 20 kg, k = 350 N/m) is given an initial displacement of 10 mm and initial velocity of 100 mm/s. (a) Find the natural frequency; (b) the period of vibration; (c) the amplitude of vibration; and (d) the time at which the third maximum peak occurs. Ans: 0.666 Hz; 1.502 sec...
  11. A

    Math used in computer algebra systems

    I am recently very interested in computer algebra systems and was thinking about the maths in it. Basic things that CAS does is algebra(solve set of equations), integration, limits, series etc. Various algorithms are used for such operations. For e.g.:- for integration there is an algorithm...
  12. A

    Cross products for unit vectors in other coordinate systems

    I am a bit confused often when I have to compute cross products in other coordinate systems (non-Cartesian), I can't seem to find any tables for cross products such as "phi X rho." in spherical I think that these unit vectors are considered to be "perpendicular," so would phi X rho just be "+/-...
  13. C

    Calculating Molar Energy Change in Molecular System Conversion?

    Homework Statement Consider a molecular system containing X type molecules and Y type molecules. X and Y can interconvert, and each has two energy levels (given below). The population in moles (n), of each energy state for X and Y, are given at equilibrium of T=300K. For X n0=0.8 and E0=0...
  14. J

    Thermodynamics : Open and close control systems

    Hi all, Q: How do you find out the boundary work using control volume analysis for a tire that is punctured all of a sudden? To proceed, I started off by using the tire as a control volume with one outlet. Using first Law, E(in) - E(out) = dE/dt Final Conditions: P(final) =...
  15. G

    Electrical Engineering - Control Systems - 2cnd Order System

    Homework Statement Given a electrical circuit as one below One can find the transfer function For second order systems this can be written as I know that the damping coefficient can be found using the following formula In the over damped case ζ>1 can easily occur depending on the...
  16. B

    Control Systems Theory: Determing break frequency mathematically.

    Hey there. I have an open loop transfer function TF = K/(t*s^2 + s) where K is known. Given a value for the break frequency (say, w_b = 10 rad/s), I have to determine the value of the time constant, t. I understand how do this with a bode plot, but not entirely sure how to proceed...
  17. K

    MHB Solving Linear & Nonlinear System w/ Reparametrization Function

    I have a problem on which I am stuck and would like help on how to proceed. The problem and my work is fairly lengthy, so please bear with me. **Problem:** A model for transport of a solute (moles of salt) and solvent (volume of water) across a permeable membrane has the form...
  18. A

    Question regarding systems in work & energy

    My professor (for some weird reasons) makes us write "system [body(ies)]" whenever we are asked to solve a physics problem for work and energy. Systems make me completely confused because sometimes if we have two or more systems, then the net work becomes zero. My question is this: How do I know...
  19. H

    Interatomic potentials for diatomic systems

    I have a molecular dynamics code and I want to model the reaction of O with Mg to form MgO at arbitrary temperatures. I am a little confused, however, because oxygen will exist as the diatomic molecule O2. This seems to mean that O2 molecules will have one type of interaction with a bonded...
  20. G

    Control Systems Engineering - Signal Flow Graphs

    Hi, I seem to be having some issues going from state space representation of a system to signal flow graph representation. My troubles seem to be, if I have something like this \frac{d}{dt}x_{1}(t) = v_{1}(t) In state space representation I list functions to which the derivatives are as...
  21. W

    Two basic types of horizontal stabilizer systems

    There are two basic types of horizontal stabilizer systems on most general aviation aircraft. Horizontal stabilizer with elevator, and or horizontal stabilator. If the horizontal stabilator system that is on most piper aircraft and some high performance fighter aircraft, then why are so many...
  22. U

    Optics: Whispering gallery modes in large systems

    While reading about whispering gallery modes, I have learned that whispering gallery modes can be seen for "microscopic spheres or toruses" -Wikipedia- , But can they practically be observed in relatively large prisms or glass spheres (m or even cm magnitude) ?
  23. A

    Microcontroller kit for a beginner embedded systems hobbyist

    I am interested in learning how to design embedded systems. I have a solid background in high level C++ (primarily for modelling and visualisation), but my knowledge of computer hardware is somewhat limited. I am interested in starting an embedded system design project to educate myself on the...
  24. A

    Systems and Signals questions-plots

    Systems and Signals questions---plots Homework Statement Problem: Express the bottom 5 plots in term of x(t) (the top plot) with its time shift, time scale, time reverse and superposition properties. (see attached picture) Homework Equations The Attempt at a Solution I have...
  25. G

    Control Systems Engineering - Masons Rule Help

    Homework Statement I'm trying to find \frac{V_{Load}(s)}{I_{Dist}(s)} using Mason's rule. I was able to solve for \frac{V_{Load}}{I_{Cf}(S)} using Mason's rule but am not sure how to solve for \frac{V_{Load}(s)}{I_{Dist}(s)}. http://imageshack.com/a/img31/4299/zr5.PNG Homework...
  26. K

    Fundamental thermo systems problem

    1. Unit mass of a fluid at a pressure of 3 bar, and with a specific volume of 0.18 m3/kg, contained in a cylinder behind a piston expands reversibly to a pressure of 0.6 bar according to the law p = c/v2, where c is a constant. Calculate the work done during the process. 2. P1V1=P2V2 3. I know...
  27. P

    Solving systems of linear equations

    Homework Statement x + 3y + z = 4 2x + 2y + z = -1 2x + 3y + z = 3 Find the general solution, and two particular solutions. The Attempt at a Solution y = 4; x = -1; z = -7; if I am not mistaken. So how am I supposed to find a general and two particular solutions if there is only...
  28. E

    How to Calculate Total Current for HV Distribution Feeder Systems?

    Homework Statement The attachment lists the question I'm posed in full. I have completed (i) and (ii) but am stuck on (iii) The Attempt at a Solution I know that load B draws 3.2*10^6/sqrt3 * 11 * 10^3 = 167.9 @37° and load C draws 1.8*10^6/sqrt3 * 11 * 10^3 = 94.5 @53° I need...
  29. 2

    Are Electronic Braking Systems the Future of Automotive Safety?

    Hi there, I'm currently researching for a Product Design project and was wondering if anyone had any insights into electronic braking systems. Are there any current systems being used on general automotive vehicles at moment? E.g The brake pedal represents the pressure of braking...
  30. F

    Earthing systems and other things

    I recently started working at ABB as a engineer. I wish someone here could help with some questions: 1) In a single phase IT system, why does the circuit breakers have to be bipolar? I believe it is because of a second fault occurence, but i don't really understand what happens. 2) If you...
  31. R

    Project help 'Power quality in renewable energy systems'

    I am currently undertaking a HND in Electrical Engineering and for my graded unit project I have chosen 'Power quality in renewable energy systems'. I was hoping someone could recommend a good book to help. Thanks
  32. C

    MHB How to Solve This 2nd Order ODE in Control Systems?

    I'm trying to solve this equation analytically, but I can't even find the auxiliary equation or general solution! Km = 0.5 C*e = 0 K2 = 0.03 K1 = 0.05 x* = 49
  33. G

    Engineering Control Systems Engineering - Circuits

    Homework Statement Find the transfer function, G(s) = \frac{V_{0}(s)}{V_{i}(s)} for each network shown in figure P2.3. [Section 2.4] http://imagizer.imageshack.us/v2/800x600q90/20/1ocq.png Homework Equations The Attempt at a Solution When I try and solve this problem I...
  34. M

    A mechanics problem with moving and fixed coordinate systems

    [b]1. A point P is described in terms of a fixed coordinate system XYZ with unit vectors I,J,K and a moving coordinate system xyx with unit vectors i,j,k.at a given instant the location of the origin of the moving system is 80I-90J.the velocity of P relative to moving system is 50i+45j;the...
  35. ShayanJ

    How Do Different Coordinate Systems Affect Vector Operations?

    Recently I've been studying about orthogonal coordinate systems and vector operations in different coordinate systems.In my studies,I realized there are some inconsistencies between different sources which I can't resolve. For example in Arfken,it is said that the determinant definition of the...
  36. R

    Are Oblique Coordinate Systems More Useful Than Orthogonal Systems in 2-D Space?

    In a coordinate system two axes are inclined at an acute angle θ. Is this coordinate system different from a coordinate system in which the axes are inclined at an angle (180 - θ)? if we look at the four quardents in either of the above set of axes, both are included giving the impression that...
  37. D

    Conceptual question of many particle quantum systems and state vectors

    Apologies if this seems a bit trivial, but I was hoping to clear up a bit of confusion that I'm having. First Question: When considering an N-particle quantum system, described by some wave-function, \Psi\left(\vec{r}_{1},\ldots,\vec{r}_{N}\right). Is it correct to consider each particle to...
  38. T

    Double Regulating Valves & 2-Way Valves: Why Install for Chilled Water Systems?

    In working with chilled water system, why do we install "double regulating valve" and "2 way valve" when connecting the pipe to the AHU ?
  39. A

    Solving Linear Systems (Basic Question)

    Hi. I don't understand how a solution to a linear system is obtained (for example geometrically; don't consider the substitution method and elimination), and I am feeling very frustrated. Say I have the following equations: y = x + 5 b = 2*a (the relation remains the same even if I change...
  40. S

    Thermodynamics and Open Systems

    Two caveats: One, I may or may not be posting my questions in the correct section of this forum. If not, then please kindly direct to where I should post it. Two, I studied English in college. I am not entirely ignorant of the sciences, but they are certainly not my area of expertise...
  41. N

    Hydraulic System Solutions Cambridgeshire | Design, Supply & Install

    Can anyone recommend a company in the Cambridgeshire area that offer a full hydraulic service including bespoke design, supply, installation, testing and commissioning of hydraulic control systems and solutions and systems that have been used for standard and high risk applications including...
  42. mathwhiz

    Preparing for Signals and Systems

    Signals and Systems Vs Circuits I I really just would like to know which course, in your opinion, was more difficult circuits I or signals? I've already taken circuits and signals is up next. Also, what should I be reviewing in order to prepare myself, during the break, for Signals and...
  43. S

    Topological Conjugation between two dynamical systems

    Find a topological conjugation between g(x) and T(x) where g and T are mappings (both tent maps [graphically speaking]) g:[-1, 1] → [-1,1] g(x) = 1-2|x| T:[0,1] → [0, 1] T(x) = 2x when x ≤ 1/2 and 2(1-x) when x ≥ 1/2 h ° T = g ° h (homeomorphism) h:[0, 1] → [-1, 1] h(x) = cos(∏x)...
  44. S

    Topological Conjugation between two dynamical systems

    Homework Statement Find a topological conjugation between g(x) and T(x) where g and T are mappings (both tent maps [graphically speaking]) Homework Equationsg:[-1, 1] → [-1,1] g(x) = 1-2|x| T:[0,1] → [0, 1] T(x) = 2x when x ≤ 1/2 and 2(1-x) when x ≥ 1/2 h ° T = g ° h (homeomorphism)The...
  45. I

    Accuracy of robotic positioning systems

    Hi friends, I search after examples or videos or names of robots or machines that work in a very accurate scale something like one millimeter of accuracy or better accuracy, so if you know about a robot or machine that work very accuracy so I will glad if you can write this in this thread.
  46. N

    Advanced Control Systems in Cambridgeshire: Find a Provider

    Can anyone recommend a company that provide advanced control systems for marine and civil engineering in the Cambridgeshire area? Thank you
  47. D

    Delocalization in metals and conjugated systems

    Hi Fellow Members, I am a bit confused about delocalization concept. Since, in organic chemistry we have been told that delocalization only exits between conjugated systems but in inorganic chemistry there is delocalization of electrons in metals with no double bonds. Isn't it...
  48. M

    Thermodynamics - closed systems

    Homework Statement A cylinder fitted with a piston contains air at 1.0 Bar and 17°C. The gas is compressed according to the law PVn = const., until the pressure is 4 bar when the specific volume is found to be 28% of the initial value. Heat is then added to the air at constant pressure until...
  49. M

    MHB Solving Systems of Linear Equations with ljx.m

    Hey! I need some help using the Matlab function ljx.m for solving a system of linear equations. I found a solved example for A= \bigl(\begin{smallmatrix} 1 & -1 &0 & 1\\ 1 & 0& 1 & 0\\ 1 &1 &2 & -1 \end{smallmatrix}\bigr) and b= \bigl(\begin{smallmatrix} 1\\ 1\\ -1 \end{smallmatrix}\bigr)...
  50. A

    Other than ZFC, what other axiomatic systems are useful?

    Other than ZFC, what other axiomatic systems have been shown to be useful to the real world? I'm a layman that is reading through the Wikipedia articles and it seems like the axioms are becoming more Philosophy than Math. We can use a different axiomatic system other than ZFC, but are there...
Back
Top