Large-scale Ferrofluid Simulations on Graphics Processing Units

We present an approach to molecular-dynamics simulations of ferrofluids on graphics processing units (GPUs). Our numerical scheme is based on a GPU-oriented modification of the Barnes-Hut (BH) algorithm designed to increase the parallelism of computations. For an ensemble consisting of one million of ferromagnetic particles, the performance of the proposed algorithm on a Tesla M2050 GPU demonstrated a computational-time speed-up of four order of magnitude compared to the performance of the sequential All-Pairs (AP) algorithm on a single-core CPU, and two order of magnitude compared to the performance of the optimized AP algorithm on the GPU. The accuracy of the scheme is corroborated by comparing the results of numerical simulations with theoretical predictions

On factorization hierarchy of equations for banana Feynman amplitudes

We present a review of the relations between various equations for maximal cut banana Feynman diagrams, i.e. amplitudes with propagators substituted with $\delta$-functions. We consider both equal and generic masses. There are three types of equation to consider: those in coordinate space, their Fourier transform and Picard-Fuchs equations originating from the parametric representation. First, we review the properties of the corresponding differential operators themselves, mainly their factorization properties at the equal mass locus and their form at special values of the dimension. Then we study the relation between the Fourier transform of the coordinate space equations and the Picard-Fuchs equations and show that they are related by factorization as well. The equations in question are the counterparts of the Virasoro constraints in the much-better studied theory of eigenvalue matrix models and are the first step towards building a full-fledged theory of Feynman integrals, which will reveal their hidden integrable structure.Comment: 13 page

Irreducible representations of simple Lie algebras by differential operators

We describe a systematic method to construct arbitrary highest-weight modules, including arbitrary finite-dimensional representations, for any finite dimensional simple Lie algebra $\mathfrak{g}$. The Lie algebra generators are represented as first order differential operators in $\frac{1}{2} \left(\dim \mathfrak{g} - \text{rank} \, \mathfrak{g}\right)$ variables. All rising generators ${\bf e}$ are universal in the sense that they do not depend on representation, the weights enter (in a very simple way) only in the expressions for the lowering operators ${\bf f}$. We present explicit formulas of this kind for the simple root generators of all classical Lie algebras

Finding a point of growth for domestic producers : focus on food products with a short shelf life

The article proves the relevance of the production of food products with a short shelf life by domestic producers, analyzes the findings of theoretical works related to the study of consumer choice and the formation of consumer habits, presents examples of successful competition between regional producers in various regions of the country with federal players. The significance of food production with a short shelf life as a point of growth for domestic business is substantiated and the opportunities and advantages of production of these types of products and the possibility of their promotion in various territories are shown.peer-reviewe

SURVEI MINAT SISWA KELAS VIII PADA PERMAINAN TENIS MEJA DI SMPN 2 RANGKASBITUNG TAHUN 2021

ABSTRAK Penelitian ini dilatar belakangi belum maksimalnya sarana dan prasarana pada permainan tenis meja. Tujuan dari penelitian ini adalah untuk mengetahui seberapa besar minat siswa kelas VIII pada permainan tenis meja di SMPN 2 Rangkasbitung tahun 2021. Penelitian ini merupakan penelitian deskriptif kuantitatif. Metode yang digunakan adalah survei dengan instrument menggunakan angket. Subjek dalam penelitian ini adalah seluruh siswa kelas VIII SMPN 2 Rangkasbitung tahun 2021 yang berjumlah 267 siswa, sedangkan sampel penelitian yang diambil sebanyak 15% berjumlah 40 siswa. Teknik analisis data menggunakan statistik deskriptif dengan persentase. Berdasarkan hasil penelitian dan pembahasan sebelumnya yaitu hasil penelitian minat siswa kelas VIII pada permainan tenis meja di SMPN 2 Rangkasbitung tahun 2021 sebagian besar berkategori tinggi 60%, kategori sangat tinggi sebesar 35%, kategori sedang sebesar 5%. Hasil tersebut dapat disimpulkan bahwa minat siswa kelas VIII pada permainan tenis meja di SMPN 2 Rangkasbitung tahun 2021 adalah tinggi. Kata Kunci : Minat, Permainan Tenis Meja ********* ABSTRACT The background of this research is that the facilities and infrastructure in the table tennis game are not maximized. The purpose of this study was to find out how much interest in class VIII students in table tennis at SMPN 2 Rangkasbitung in 2021. This research is a quantitative descriptive study. The method used is a survey with an instrument using a questionnaire. The subjects in this study were all grade VIII students of SMPN 2 Rangkasbitung in 2021, totaling 267 students, while the research sample taken was 15% of 40 students. The data analysis technique used descriptive statistics with percentages. Based on the results of previous studies and discussions, namely the results of research on the interest of class VIII students in the table tennis game at SMPN 2 Rangkasbitung in 2021, most of them were in the high category of 60%, very high category of 35%, moderate category of 5%. These results can be concluded that the interest of class VIII students in table tennis games at SMPN 2 Rangkasbitung in 2021 is high. Keywords : Interest, Table Tennis Gam