Recent content by Aerostd

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    Convergence of a recurrence equation: x(k+1) = 0.5x(k) + u(k)

    Something seemed fishy to me, so I went back to this and found a mistake. I need your help to see if what I have done this time is correct and legal. I'll start from the top again. -- Show that x(k) goes to zero in the limit. Let ϵ>0. Now, we know that 0.5k and u(k) both go to zero(by...
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    Convergence of a recurrence equation: x(k+1) = 0.5x(k) + u(k)

    -- Show that x(k) goes to zero in the limit. Let \epsilon > 0 . Now, we know that 0.5^{k} and u(k) both go to zero, therefore, for all \epsilon_{1} > 0 , there exists k_{1}>0, such that if k > k_{1}, then | 0.5^{k} | < \epsilon_{1} and | u(k) | < \epsilon_{1}. Now x(k) = | 0.5^{k}...
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    Convergence of a recurrence equation: x(k+1) = 0.5x(k) + u(k)

    Sorry about that. I understand and can solve it now. Thanks.
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    Convergence of a recurrence equation: x(k+1) = 0.5x(k) + u(k)

    Hi. Thanks a lot for replying. If I replace 0.5^{i}u(k-i) by M where M is it's max value, then I can get an upper bound on x(k). But this upper bound might blow up as k tends to infinity (for the case where M>1). I won't be able to conclude what happens to x(k) as k tends to infinity.
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    Convergence of a recurrence equation: x(k+1) = 0.5x(k) + u(k)

    Homework Statement Hello. I am trying to prove a result that I have been making use of, but never really proved. Consider the recurrence equation x(k+1) = 0.5 x(k) + u(k), where u(k) is a bounded sequence. For this problem, assume that u(k) goes to zero. I want to prove that x(k) goes to...
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    If xn = yn + zn, and xn, yn, zn >0, and xn xonverges, then yn converges.

    Actually I just thought of one. Thanks. :confused: as always.
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    If xn = yn + zn, and xn, yn, zn >0, and xn xonverges, then yn converges.

    Homework Statement Let x_{n} = y_{n} + z_{n} Also, x_{n}>0 , y_{n}>0 , z_{n}>0 . We also know that x_{n} converges. Prove that y_{n} converges. Homework Equations I want to use the Cauchy criterion because the limits are not given. So start with an [tex] \epsilon >0 [/itex]...
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    Understanding Hausdorff Dimension of 1-d Line

    Hi, I had a question about understanding some basic thing about the Hausdorff dimension. Specifically, I'm trying to understand why the two dimensional Hausdorff dimension of a 1-d line is zero. In terms of the two dimensional Lebesgue measure, I can see that I can cover the line by a...
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    Control System Help (not an EE)

    I think your system has two degrees of freedom. You should have two differential equations, one for acceleration of x_{1} and one for acceleration of x_{2}. Also, It seems from the problem statement that you have one input f, and two outputs x_{1} and x_{2}. Which means that you should have...
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    Understanding Product Sigma Algebras: Definition, Notation, and Example

    Thanks a lot. I guess now I will move on to the next page in the book. I don't know if I should open a new thread or not but here goes. This is Proposition 1.3 in Folland. I am interested more in the notation than in the proof given in the book. The proposition is If A is countable, then the...
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    Understanding Product Sigma Algebras: Definition, Notation, and Example

    Homework Statement I should mention beforehand that I do not come from a math background so I may ask some trivial questions. I am reading the book "Real Analysis" by Folland for a course I am taking and am attempting to understand a definition of product sigma algebra. It is stated in the...
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    Bead sliding on a rotating straight rigid wire.

    Homework Statement I think I will start with the figure below: The wire of infinite length rotates about the point "a" with constant angular speed. The bead starts out at rest. There is no friction or gravity. I have already derived the equations of motion for this system (I used...
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    Observability and existence and uniqueness

    My question is that if two different initial conditions give you the same free response, doesn't that violate the definition of a state?
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    Observability and existence and uniqueness

    Homework Statement I have set up this problem for myself. Let P be a system of the form x' = Ax + Bu y = Cx + Du The definition of a "state" is: "x(t) is a state for a system P if knowledge of x at some initial time t_{0} and the input u(t), t \geq t_{0} is sufficient to uniquely determine...
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    Using SVD to solve a set of equations.

    Homework Statement This is not a homework problem. I encountered this while working with total least squares for the first time. Ultimately a point is reached where Az=0 must be solved. z is of the form [x,1]^{T}. Let A be nxm, z be mx1. Suppose A is rank deficient by one. So the SVD of A...
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