Commuting foliations

The aim of this paper is to extend the notion of commutativity of vector fields to the category of singular foliations, using Nambu structures, i.e. integrable multi-vector fields. We will classify the relationship between singular foliations and Nambu structures, and show some basic results about commuting Nambu structures.Comment: New version, with a completely new section which clarifies the relationship between singular foliations and Nambu structures. The size of the paper has doubled from 10 to 20 page

An efficient hardware logarithm generator with modified quasi-symmetrical approach for digital signal processing

This paper presents a low-error, low-area FPGA-based hardware logarithm generator for digital signal processing systems which require high-speed, real time logarithm operations. The proposed logarithm generator employs the modified quasi-symmetrical approach for an efficient hardware implementation. The error analysis and implementation results are also presented and discussed. The achieved results show that the proposed approach can reduce the approximation error and hardware area compared with traditional methods

Density-dependent phonoriton states in highly excited semiconductors

The dynamical aspects of the phonoriton state in highly-photoexcited semiconductors is studied theoretically. The effect of the exciton-exciton interaction and nonbosonic character of high-density excitons are taken into account. Using Green's function method and within the Random Phase Approximation it is shown that the phonoriton dispersion and damping are very sensitive to the exciton density, characterizing the excitation degree of semiconductors.Comment: ICTP preprint IC/95/226, Latex, 10 pages, 3 figure

THE READING CULTURE OF ENGLISH MAJORED STUDENTS AT TAY DO UNIVERSITY, VIETNAM

In the 21st century, the development of many modern entertainment facilities makes people rarely focus on reading books. So, the reading culture gradually fell into oblivion. In reality, when teachers ask students about their reading habit, students often say “we seldom read books”, they mostly read books because of teacher requests or school assignments. Therefore, the research “The reading culture of English majored students at Tay Do University” was conducted with the purpose of helping English linguistic students to acknowledge the importance of reading books. Thanks to this, they can find their own situations and spend more time reading books. The participants of this study were 100 English majored students of four classes including English Linguistic 10B, 11A, 12C and 13A at Tay Do University that were chosen randomly. The instrument used in this thesis was the questionnaire. The data from questionnaires were statistically analyzed by SPSS English version 20.0 package. Based on research results, the researcher found out some common students’ thoughts on reading culture as well as solutions to develop their reading culture in the future.  Article visualizations

Rice husk gasification for electricity generation in Cambodia in December 2014: Field trip report

Rice husks are the indigestible coatings of grains of rice. They are produced in large quantities by the rice milling industry, more than 1 million ton per year in Cambodia. In recent years, Cambodian enterprises have installed gasifiers, which burn rice husks to generate electricity. This is a two stage process: the biomass is first fed into a gasifier which produces syngas and ashes, then the syngas is cleaned and burned into an engine where it saves diesel fuel. Many of these enterprises have been in local communities currently without electricity or in fuel poverty.To learn more about the benefits and drawbacks of using rice-husk gasifiers, and to study about the sustainability challenges for deploying these technologies, the Clean energy and sustainable development lab (CleanED lab) of the University of Science and Technology of Hanoi (USTH), and the SNV Netherlands Development Organisation (SNV) have conducted a visit of several rice mills and rural electricity enterprises from 18 th to 22nd December 2014.Five rice mills and a rural electricity enterprise in Battambang, Siem Reap and Kampong Thom provinces were selected for the field survey. In addition with desk research, semi-structured interviews with gasifier users, with the representatives of Canadia Bank PLC and the Federation of Cambodian Rice Millers Association (FCRMA) during the field surveys were also conducted. This report present and justifies the main conclusions of the visit

Exotic States Emerged By Spin-Orbit Coupling, Lattice Modulation and Magnetic Field in Lieb Nano-ribbons

The Lieb nano-ribons with the spin-orbit coupling, the lattice modulation and the magnetic field are exactly studied. They are constructed from the Lieb lattice with two open boundaries in a direction. The interplay between the spin-orbit coupling, the lattice modulation and the magnetic field emerges various exotic ground states. With certain conditions of the spin-orbit coupling, the lattice modulation, the magnetic field and filling the ground state becomes half metallic or half topological. In the half metallic ground state, one spin component is metallic, while the other spin component is insulating. In the half topological ground state, one spin component is topological, while the other spin component is topological trivial. The model exhibits very rich phase diagram