Recent content by catcherintherye

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    Theory of traffic flow/ poisson arrivals and mean delay

    Hello, From the following formula in the following theorem I am to deduce the mean delay of a customer arriving at a queue. Theorem 1 Suppose that customers arrive at a single server queue according to a Poisson process mean rate q and that service times are exponentially distributed mean...
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    Finding conjugacy classes

    I was wondering if anyone knows a more efficient method of finding conjugacy classes than the one i am currently using. tex/ Example D_6* =<x,y| x^3=1, y^4=1, yx=x^2y> now to find the conjugacy classes of this group i would first write out the orbit of x <x> ={ 1x1, xxx^2, x^2xx...
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    I'm trying to prove that a linear map is injective

    hello, I've been reading some proofs and in keep finding this same argument tyo prove that a linear map is injective viz, we suppose that t(a,c) = 0 and then we deduce that a,c = 0,0. is it the case that the only way a linear map could be non injective is if it took two elements to zero? i.e. t...
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    How Do You Solve Group Ring Isomorphisms in Mathematics?

    obviously i haven't made myself clear, i'll post the question in it's entirety... Let A,B be algebras over a field F. We say that A and B are isomorphic over F written A\cong_F B when there exists a bijective ring homomorphism \varphi : A \rightarrow B which is also linear over F, i.e...
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    How Do You Solve Group Ring Isomorphisms in Mathematics?

    I have about 5 questions all of a similar form ... \mathbb{F}[C_2] \cong \mathbb{F} \times \mahbb{F} if 1+1 \neq 0 in \mathbb{F} \Re [C_3] \cong \Re \times C \Re [C_4] \cong \Re \times \Re \times C these were on the first sheet given out and I still don't know how to do...
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    Maschkes theorem/group rings

    In the statement of Maschke's theroem we are told 'Let G be a finite group and F a field in which |G| not equal to zero. As an example we are told if our group was C2 (cyclic) then we could not have F=F2 (the field with 2 elements). I fail to see how C2 and F2 are related, surely |C2|=2...
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    Complementary slackness and the transportation problem

    i don't think so, the variables y_i, z_j are dual variables, i don't think they have units as such. The primal problem was to minimize cost subject to some constraints, more specifically, minimize \sum_{i=1}^{4}\sum_{j=1}^{6}c_ij x_ij subject to x_ij \geq 0 \sum_{j=1}^{6}x_ij \leq...
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    Complementary slackness and the transportation problem

    hello,I have been given the transportation problem (T) defined by the cost matrix \left(\begin{array}{ccccccc}5&3&9&3&8&2\\5&6&3&15&7&16\\9&20&10&22&17&25\\3&7&3&14&9&14\end{array}\right) the demand vector q=(2,8,9,4,6,2) the supply vector p=(3,13,6,9) the problem is as...
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    Complementary slackness and the transportation problem

    btw, i really need a prompt answer if at all possible, this is for my referal which has to be in next week!
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    Complementary slackness and the transportation problem

    hello,I have been given the transportation problem (T) defined by the cost matrix \left(\begin{array}{ccccccc}5&3&9&3&8&2\\5&6&3&15&7&16\\9&20&10&22&17&25\\3&7&3&14&9&14\end{array}\right) the demand vector q=(2,8,9,4,6,2) the supply vector p=(3,13,6,9) the problem is as...
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    Solving Linear Program (P): Adding Slack Variables

    i am working with the following linear program (P) max 2x_1 - x_2 subject to x_1 \leq 3 - x_1 + x_2 \leq -1 x_1 + x_2 \geq 2 x_1, x_2 \geq 0 my question is this, when introducing slack variable...
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    Solving Linear Program (P): Adding Slack Variables

    i am working with the following linear program (P) max 2x_1 - x_2 \\ subject to x_1 \leq 3 \\ - x_1 + x_2 \leq -1 \\ x_1 + x_2 \geq 2 \\ x_1, x_2 \geq 0 my question is this, when introducing slack variable...
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    Sylow Theorem Part 2: Find Order of Subgroup PQ

    okay so I'm going through the proof of sylow part 2, i.e. the bit that says if N_p is the number of subgroups of G of order p^n then N_p \equiv1modp now I have got to the part where I have taken the subgroup P of order P^n that you get from sylow part 1 and I have to show that it is a...
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    Factorisation of x^22 -3x^11 +2

    factorize x^{22} -3x^{11} + 2 right so I have p(x) = (x^11 -2)(x^11 - 1) (x^11 -2) satifies eisentstein, obviously x-1 is a factor of the second factor. Long division reaps x^{10} + x^9 +...+x + 1 the solution asserts that this is also irreducible, but I do not see this?? Is this...
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    Failure of the sylow counting argument

    show that there is a normal subgroup of G of order 5 when G is a group of order 30. My friend just called me with this problem, he said the usual method of solution fails. (i.e. using sylow and then showing that the subgroup is unique and deducing that it must therefore be normal), I told him to...
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