امروزه در مبحث محاسبات رآکتورهای هسته‌ای مثل فرسایش و مدیریت سوخت، تحلیل گذرا بازسازی توان میله‌های به دنبال روش‌هایی جهت استفاده کدهای هستند که علاوه بر دقت قابل‌قبول از هزینه زمان بهینه‌ای برخوردار باشند. این پژوهش با گسسته‌سازی معادله پخش نوترون روش نودال بسط شار جریان ‌متوسط مرتبه بالا نشان داده می‌شود روش‌ بهینه قابل‌قبولی بهره می‌برد. مستقیم الحاقی نوترون، برای هندسه مربعی دوبعدی دو گروه ...

The recent emergence of the discrete fractional Fourier transform (DFRFT) has caused a revived interest in the eigenanalysis of the discrete Fourier transform (DFT) matrix F with the objective of generating orthonormal Hermite-Gaussian-like eigenvectors. The Grünbaum tridiagonal matrix T – which commutes with matrix F – has only one repeated eigenvalue with multiplicity two and simple remaining...

We propose a design procedure for the real, equal-norm, lapped tight frame transforms (LTFTs). These transforms have been recently proposed as both a redundant counterpart to lapped orthogonal transforms and an infinite-dimensional counterpart to harmonic tight frames. In addition, LTFTs can be efficiently implemented with filter banks. The procedure consists of two steps. First, we construct n...

We introduce a new discrete fractional Fourier transform (DFrFT) based on only the DFT matrix and its powers. Eigenvectors of the DFT matrix are obtained in a simple-yetelegant and straightforward manner. We show that this DFrFT definition based on the eigentransforms of the DFT matrix mimics the properties of continuous fractional Fourier transform (FrFT) by approximating the samples of the co...

A fundamental result of free probability theory due to Voiculescu and subsequently refined by many authors states that conjugation by independent Haar-distributed random unitary matrices delivers asymptotic freeness. In this paper we exhibit many other systems of random unitary matrices that, when used for conjugation, lead to freeness. We do so by first proving a general result asserting “asym...

background: a balanced nutrition schedule provides the essential substances for proper oral health. objectives: the aim of this study was to investigate the association between dental caries and body mass index in 6-11 year-old children in zahedan. materials and methods: in this cross-sectional study 1213 children (670 girls, 543 boys) were included. body mass index (bmi) and clinical examinati...