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.

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  1. P

    Finding LTI (Linear Time-Invariant Systems)

    Homework Statement Tell whether following systems are i. linear and ii. time-invariant: $$y(t) = \int_{-\infty}^t x(\tau)d\tau$$ $$y(t) = \int_{0}^t x(\tau)d\tau$$ $$y(t) = \int_{t-1}^{t+1} x(\tau)d\tau$$Homework Equations N/AThe Attempt at a Solution I'm a little thrown off by the integrals...
  2. JonnyMaddox

    Non-square linear systems with exterior product

    Hi, how can I compute the general solution of a system of linear equations? Non-square systems for example. I have the book Linear Algebra via exterior products, but it is the worst book in the history of math books, I think I'll burn it somehow, whatever. I can calculate the solution with the...
  3. U

    Can I use 2 different coordinate systems for one system?

    Homework Statement As shown in the image below, can I use 2 different co-ordinate systems when drawing the free body diagram for each object? Homework Equations The Attempt at a Solution
  4. T

    Exploring Complex Roots of Underdamped Systems: Why the Sine Term?

    I'm trying to do some refreshing of differential equations featuring damped systems. Specifically, I have a question regarding the differential equation solution to an under damped system involving complex roots. Referring to the attached pdf, an under damped system will yield a complex...
  5. S

    Radar systems in cars - health hazard?

    Many modern cars now employ radar systems for intelligent cruise control as well as blind spot monitoring. Can the radar waves that are reflected back to the vehicle for these applications pose a health hazard to the vehicle occupants?
  6. J

    How Does Scoring Simplify Chess Rating Systems?

    All chess rating systems including the Elo rating system are based on a procedure called "scoring" which assigns a score of 1 for a win, 0 for a loss, and 1/2 for a draw. This procedure reduces the trinomial nature of chess game outcomes to a binomial variable and thereby greatly simplifies the...
  7. M

    Power Loss Calculation in Distribution Systems

    what is the best software to calculate power losses in a distribution system?
  8. A

    Pressure of thermodynamical systems and gravity

    In almost every textbook I have seen, pressure is said to be one of the most important state variables of a thermodynamical system. But if the system is three-dimensional and on planet Earth, it is not constant! This problem, however, is neglected in every reference I consulted. It seems to...
  9. MartinJH

    Engineering What is a typical day like for a systems engineer?

    Hopefully this is in the correct section. I'm studying systems engineering and I'd like to know a typical day in the life of such. I've done some research but I can't quit assume what a working day would involve and perhaps, generally, what I can focus on. * What sort of projects are worked on...
  10. M

    A question about Operating Systems

    I have always been wondering that why there is only one commercial operating system which is Microsoft Windows whereas there are a lot of commercial cars, computers, publishers. Best Regards.
  11. T

    Exploring the Feasibility of Road Downhill Propulsion Systems

    Having recently taken up road downhilling, I want to investigate the feasibility of producing a personal, wearable thrust driven propulsion system. Doesn't have to be terribly powerful, controllability should be via twistgrip maybe. I'm drawing pictures of an ergonomically-designed frame which...
  12. H

    Resonant frequency calculations for 'solid object' systems

    Hi, thanks for stopping by :) This is for a big assignment (Yr 12). I asked my physics teacher this, but she couldn't give me a definite answer, and neither could my music teacher who previously studied physics, and then he messaged an engineer he knew, who hasn't replied yet... ~ Given...
  13. B

    What is the tension in the rope of a pulley system in equilibrium?

    Homework Statement When a 50-kg mass on a pulley is allowed to drop, the friction in the pulley creates a constant 200 N force upward. What is the tension in the rope? Homework Equations F (upward) = F (downward) The Attempt at a Solution I attempted this problem by assigning the...
  14. J

    Casual talk. Constrained Hamilton systems. Dirac brackets.

    Casual talk. Constrained Hamilton systems. Dirac-Poisson brackets. Casual talk. Constrained Hamilton systems. Dirac-Poisson brackets. Hi guys, I think I have finally succeeded in understanding the ideas which Dirac explained in the two first chapters of his book "Lectures on Quantum...
  15. C

    Mapping Coordinate Systems Using Quaternions

    During the course of working with inertial measurement units (IMU) I have run into a problem. The issue is that an IMU reports accelerations relative to the IMU's orientation rather than it's initial orientation. The IMU's initial orientation is the identity quaternion (1,0,0,0). All changes...
  16. N

    Making the Right Choice: Deciding Between Physics & Computer Information Systems

    Hey guys! I am in community college, and this will be my first semester. But I am basically confused in making perfect choice for my major. And the reason is I am good at Math, but bad at Chemistry and Biology. Following are the courses required to obtain an Associate degree in respective...
  17. F

    Power Law Derivation for dynamic systems

    Just a quick question. Let A and B be two points. Electrical work is defined as the amount of energy it takes to move an amount of charge Q through a potential difference VB-VA (for our purposes here, we will assume that the voltage values are measured with respect to an Earth ground) and is...
  18. E

    Is having Circuits 2 a corequisite for Signals and Systems viable?

    Hello all, I am currently studying as an EE and realized I messed up something with my career path. I am not sure if it possible to get an internship at a company for primarily DSP if you haven't taken a DSP class? If not, things could be mended if it were possible to take circuits 2...
  19. L

    Solve Systems of Equations 17.3-(17.3)e^(-92.34940680845194549420x)^y

    17.3-(17.3)e^(-92.34940680845194549420x)^y)=17.30181504460159157646-((17.3-(17.3)e^((-0.00118329948908244714x)^y)) anyone know how to solve this or a calculator that can?
  20. L

    Time averages. Charge density wave systems

    Homework Statement How to get equation ## \frac{d \theta}{dt}=-\omega_d+\omega_1\cos (\omega t)## where ##\omega_d## is the average drift frequency and ##\omega_1## is proportional to the amplitude of the ac current. from ## \frac{d \theta}{dt}=\omega_{co}(\frac{V(t)}{V_T}-\sin \theta) ##...
  21. STEMucator

    Isolated Systems, with ##\Delta E_{th}##

    Homework Statement A ##m = 2.0 kg## box slides along a floor with speed ##v_1 = 4.0 \frac{m}{s}##. It then runs into and compresses a spring until the box stops. Its path to the initially relaxed spring is frictionless ##(F_f = 0)##, but as it compresses the spring, kinetic friction with a...
  22. L

    Robotics and automated systems, is it useful to a mechanical engineer?

    Hi i just finished my first year of general engineering and am on a 4 month break. If there are any senior engineering students or engineers out there, I just want to know if its useful to take a two month course in embedded systems and microcontrollers. Thanks
  23. S

    Why Is Infinite Degrees of Freedom Important for Thermal States?

    Are electrons closed systems?
  24. M

    Astronomy; Precession data co-ordinate systems

    Homework Statement Use a coordinate conversion application to roughly map out the amount of precession in coordinate positions (R.A and Declination) in the sky between 1950 and 2000. Homework Equations I can easily find a converter on the internet The Attempt at a Solution I...
  25. L

    Mechanical Principles - Rotating Systems

    A load of mass 250kg is required to be lifted by a means of a winding drum and cable. The mass will be initially at rest, accelerated uniformly upwards for 4 seconds and then decelerated uniformly for one second. such that a final height of 10.5 metres is gained. The winding drum has a mass...
  26. F

    Angle between two orthogonal coordinate systems

    If two orthogonal coordinate systems (xyz and x'y'z') share a common origin, and the angles between x and x', y and y', and z and z' are known. What is angle between the projection of z' on the xy plane and the x axis? Thank you for your help!
  27. K

    Designing Lag or Lead Compensators with 3rd order systems

    For a 3rd order system, can I use 2nd order approximation (granted dominant pole is ≈5 Tau away from third pole), when designing a Lead or Lag compensator? Can this OLTF = K/{s(0.1s+1)(s+1)} be approximated to 10K/{s(s+1) which ultimately gives CLTF=10K/{s(s+1)+ K} ? and then design...
  28. S

    [Signals and Systems] What's the signinfance of negative time?

    Hello all, This one thought came to my mind just now. What's the physical significance of signal representation in negative time, i mean second and third quadrant. So for example, sin(t) and sin(t).u(t) aren't they same for all practical purposes? I know, mathematically they are...
  29. I

    What is the significance of using a log scale in bode plots?

    How did they get the blue box? I know where they got the 0.5 inside the brackets from but not sure about the rest. The bode plot in my data book has log10(wt) as the x-axis..
  30. N

    Detect planets in solar systems like ours

    Hi, With today's technologies, if our exact solar system were at a few light-years from us, could we detect its planets ? /Nico
  31. kq6up

    Using Matrices to Solve Systems of Masses and Springs

    I am going through Mary Boas' "Mathematical Methods in the Physical Sciences 3rd Ed". I finished the chapter 3 section 12 problem set, but I do not understand how she gets eq. 12.39. These don't seem obviously equal to each other. Here is the equation: $$\lambda Tr=Vr$$ Where T is a matrix...
  32. zdcyclops

    Emergent coordinate systems in quantum physics

    Do unobserved particles exchange information with other particles? If not then they are not only unobserved but also un-observing, which would seem to mean that they not only do not have a well defined position but that the very concept of position does not exist for them, nor does distance or...
  33. I

    Thermodynamics: Cycles and systems

    In the lecture notes my university provided I am told that according to the first law of thermodynamics: ΣQ = ΣW (for a cycle) ΣQ = ΣW + ΔU (for a closed system) Does this mean that there is always a change in internal energy in a closed system? Or can ΔU=0? In other words, can ΣQ = ΣW, and if...
  34. K

    Understanding Bode Plots for Second Order Systems with ς‚= 0

    hey guys, i have a question regarding bode plot g(s)= 1/(s2+4) i did get the magnitude plot correct but i am unable to understand the phase plot. by calculating on paper i got 0° but in MATLAB it changes from -360° to -180° i haven't understood how the initial phase is -360 which...
  35. M

    Information on three phase systems

    There is a lecture called fundamentals of electric and electronics and there is a new topic in that lecture I have to learn but I have little information on it. Topic is three phase systems or three phase power calculations or something like that. There are big letter such as R,S which...
  36. T

    Question about automotive braking systems

    This may not be the proper place to ask this so forgive me if wrong. Can someone direct me to the Federal Reg that "specifically" dictates that hydraulic braking systems MUST have 45 deg. "double" flare connections? I'm involved in a protracted forum thread regarding 45 deg double flare on...
  37. P

    Closed Systems and Isolated Systems

    Within the scope of classical mechanics, what exactly is the definition of a closed system, and of an isolated system? Also, do these definitions differ in thermodynamics? And does the law of conservation of linear momentum apply to a closed system or an isolated system?
  38. A

    Is Computational Systems Biology a Good Major for Engineering Grad School?

    I was wondering what are the general opinions on the field? I am a freshman physics major planning to switch to this major. I can basically pursue an emphasis on neurosystems, CS, molecular biology or bioinformatics. If I do end up majoring in CSB, I will probably double major with math or...
  39. B

    What is the Wronskian of the given solution vectors?

    Homework Statement We know that X= (1 over 3)e^t+(4 over -4) te^t is a solution to X'=(2 1 over -1 0)X. Verify that the solution vectors are linearly independent on (-∞,∞).Homework Equations I know that the wronskian of the solution vectors cannot be 0 if they are linearly independent.The...
  40. A

    Discover Tension in Systems I and II: A Physics Homework Question

    Homework Statement PLEASE click on attached picture below: What can be concluded about the tension in the cords holding the balls stationary in Systems I and II when both systems are at rest? In both systems the mass of the larger ball M2 is exactly twice the mass of the smaller ball...
  41. T

    Measuring MVARs in the Field: EMS Systems Explained

    How are MVARs actually measured in the field? How do EMS systems know the difference between MW and MVARS as opposed to an absolute value of MVA? Thanks!
  42. V

    Difference between formal systems and theories

    A theory is a subset of a formal language together with a set of inference rules on that formal language in which the members of the theory need no premises to be true, right? So if I had a subset ##\mathcal{T}## of a formal language ##\mathcal{F}##, and a set of inference rules in which all...
  43. F

    Lattice systems and group symmetries

    Dear all, In Marder's Condensed matter physics, it uses matrix operations to explain how to justify two different lattice systems as listed in attachment. However, I cannot understand why the two groups are equivalent if there exists a single matrix S satisfying S-1RS-1+S-1a=R'+a'...
  44. O

    Comparing Belt & Gear Systems for Power Transfer

    What are the factors to take into account when deciding between using a belt or a gear system for transferring power? Thanks
  45. D

    Expanding the definition of inertial coordiante systems.

    Einstein has a thought experiment with two trains which he uses to prove linear motion without acceleration is inertial. Inertial means there is no physical test which will prove which train is moving and which is stationary, no coordinate system is preferred and that coordinate system are...
  46. L

    Orienational order parameter in isotropic systems

    Hi everyone, I have what may be a dummy question. In NMR or in the study of liquid crystals for example, an order parameter S is often used: S=\left\langle\frac{1}{2}\left(3\cos^{2}\theta-1\right)\right\rangle with \theta the angle of the molecule with a "director" (the magnetic field in...
  47. S

    MHB How to Prove the Zero Solution in Homogenous Linear Systems?

    may I get hints on how to show that if k∈R. if x is a solution of the IVP x' = Ax with x(k)= 0(vector0 then x= 0(vector)
  48. O

    MHB Proving the Uniqueness of Solutions to Autonomous Systems: A Study on λ and R_n

    i am studying autonomous system, i came across this proposition λ is in R and vector b is in R_n where the IVP x' = Ax + c , with x(λ) = b has at most one solution is it possible to prove this
  49. J

    Bode Plots & Frequency in Control Systems: Demystified

    What frequency are they referring to when they plot magnitude versus frequency in a bode plot of a control system? I don't understand where frequency comes from in control systems. I've researched this and I'm still very confused by what is meant by frequency.
  50. I

    Newton's 2nd law for open mass systems

    Sorry, but this will be a long post. This isn't homework, I'm reviewing physics after many years of neglect. Halliday & Resnick, 4th Ed., section on variable mass and rockets, refers the interested reader to an article, "Force, Momentum Change, and Motion," Martin S. Tiersten, Am. J...
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