0

introduction: attenuation correction is a useful process for improving myocardial perfusion spect and is dependent on activity and distribution of attenuation coefficients in the body (attenuation map). attenuation artifacts are a common problem in myocardial perfusion spect. the aim of this study was to compare the effect of attenuation correction using different attenuation maps and different...

We examine the power of quantum Turing machines (QTM’s) which compute string-valued functions of their inputs using small workspace. A (probabilistic or quantum) Turing machine has three tapes: A read-only input tape, a read/write work tape, and a “1.5-way" write-only output tape. Consider a partial function f : Σ 1 → Σ 2 , where Σ1 and Σ2 are the input and output tape alphabets, respectively. ...

The correction of certain errors in mitosis requires capture and release: new kinetochore microtubules must be captured and old, misdirected ones must be released. We studied capture and release in living grasshopper spermatocytes. Capture is remarkably efficient over a broad range in the angle at which a microtubule encounters a kinetochore. However, capture is inefficient when kinetochores po...

We study space-efficient algorithm for computing a centerpoint for a set P of n points in R, where the points in P are given in a read-only array. We propose an algorithm that finds a centerpoint of P in O(T (n) log n) time using O(S(n)) extra space, where T (n) and S(n) are the time and extra space complexities of computing the median among a set of n elements stored in a read-only array.