浅い感潮水路における塩分と潮流の空間的および時間的変動性

広島大学(Hiroshima University)博士(工学)Doctor of Engineeringdoctora

A characterization of the algebraic degree in semidefinite programming

In this article, we show that the algebraic degree in semidefinite programming can be expressed in terms of the coefficient of a certain monomial in a doubly symmetric polynomial. This characterization of the algebraic degree allows us to use the theory of symmetric polynomials to obtain many interesting results of Nie, Ranestad and Sturmfels in a simpler way.Comment: 14 page

Strong consistencies for weighted constraint satisfaction problems

Cette thèse se focalise sur l'étude de cohérences locales fortes afin de résoudre des problèmes d'optimisation sur des réseaux de fonctions de coûts (ou réseaux de contraintes pondérées). Ces méthodes fournissent le minorant nécessaire pour des approches de type "Séparation-Evaluation". Nous étudions dans un premier temps la cohérence d'Arc virtuelle (VAC), une des plus fortes cohérences d'arcs du domaine, qui est établie via l'établissement de la cohérence d'arc dure dans une séquence de réseaux de contraintes classiques. L'algorithme itératif pour établir VAC est amélioré via l'introduction d'une incrémentalité accrue, exploitant la cohérence d'arc dynamique. La nouvelle méthode est aussi capable de maintenir VAC efficacement pendant la recherche lorsque les réseaux de contraintes pondérées sont dynamiquement modifiés par les opérations de branchement. Dans une seconde partie, nous nous intéressons à des cohérences de domaines plus fortes, inspirées de cohérences similaires dans les réseaux de contraintes classiques (cohérence de chemin inverse, réduite ou Max-réduite). Pour chaque cohérence dure, plusieurs cohérences souples ont été proposées pour les réseaux de contraintes pondérées. Les nouvelles cohérences fournissent un minorant plus fort que celui des cohérences d'arc souples en traitant les triplets de variables connectées deux à deux par des fonctions de coûts binaires. Dans cette thèse, nous étudions les propriétés des nouvelles cohérences, les implémentons et les testons sur une variété de problèmes.This thesis focuses on strong local consistencies for solving optimization problems in cost function networks (or weighted constraint networks). These methods provide the lower bound necessary for Branch-and-Bound search. We first study the Virtual arc consistency, one of the strongest soft arc consistencies, which is enforced by iteratively establishing hard arc consistency in a sequence of classical Constraint Networks. The algorithm enforcing VAC is improved by integrating the dynamic arc consistency to exploit its incremental behavior. The dynamic arc consistency also allows to improve VAC when maintained VAC during search by efficiently exploiting the changes caused by branching operations. Operations. Secondly, we are interested in stronger domain-based soft consistencies, inspired from similar consistencies in hard constraint networks (path inverse consistency, restricted or Max-restricted path consistencies). From each of these hard consistencies, many soft variants have been proposed for weighted constraint networks. The new consistencies provide lower bounds stronger than soft arc consistencies by processing triplets of variables connected two-by-two by binary cost functions. We have studied the properties of these new consistencies, implemented and tested them on a variety of problems

A STUDY ON ERRORS IN PRONOUNCING DENTAL SOUNDS OF ENGLISH-MAJORED SOPHOMORES AT TAY DO UNIVERSITY, VIETNAM

It is not deniable that pronunciation is considered one of the most crucial parts of learning English helping learners enhance their communication in both speaking and listening comprehension. To reach a level of a clear and precise pronunciation has never been an effortless task; however, it is a far more problematic one for English majored students regardless of their learning years. For this reason, the study entitled “Common Errors in Pronouncing Dental Sounds of English-Majored Sophomores at Tay Do University” was implemented with the aim at investigating the errors that English-majored students encountered in pronouncing dental sounds. 80 English-majored sophomores from course 14 at Tay Do University were selected to participate in the study. Questionnaires and recording tests were delivered to the participants for collecting data and getting more information. The collected data from the two instruments mentioned above was all analyzed afterward. The findings of the research revealed that sophomores of English major often mispronounced the dental sounds, including omission and substitution. The results of this study may also be useful for those who are interested in this field. Article visualizations

EULER CHARACTERISTIC OF TANGO BUNDLES

We are interested in a vector bundle constructed by Tango (1976). The Tango bundle is an indecomposable vector bundle of rank n-1 on the complex projective space P^n. In particular, we show that the Euler characteristic of the Tango bundle on P^n is equal to 2n-1

A research on the performance of down-flow hanging sponge (DHS) reactor treating domestic wastewater

The aim of this study was to evaluate the performance of a down-flow hanging sponge (DHS) system in treating domestic wastewater. A pilot-scale of DHS system with a capacity of 60 L was designed and fabricated from polyvinyl chloride (PVC). The dimensions of DHS system are 1.5 m in height and square surface with 0.2 m in width, consists of three identical segments connected vertically in series. Each segment was filled by polyurethane sphere containing sponge. The total area of sponge and polyurethane sphere was 3,300 m2 m-3, density at 150 kg m-3, void ratio at 90%. DHS system was operated at ambient temperature within 82 days and stepwise increased of organic f rate from 0.5 to 1 and 1.5 kg COD m-3 d-1. The results showed that, this system performed well throughout the operational period and achieve the maximum removal of COD, BOD5, NH4+-N, and TN as 80%, 83%, 65% and 60%. The effluent of wastewater from DHS system achieved the requirement for National technical regulation on domestic wastewater of Vietnam type B QCVN 14:2008/BTNMT. In conclusion, the performance of DHS system indicated a high potential for application in removing organic matter and converting nitrogen ammonia to nitrogen nitrate, however it did not perform well for the removal of total nitrogen, it is necessary to study further by providing an anoxic zone in the system to enhance the treatment of nutrient in wastewater

Genome Sequence of a Virulent African Swine Fever Virus Isolated in 2020 from a Domestic Pig in Northern Vietnam

This study reports the genome sequence of an isolated African swine fever (ASF) virus (VNUA-ASFV-05L1/HaNam) obtained at the fourth passage on pulmonary alveolar macrophages. The virus was isolated during a typical acute ASF outbreak in pigs in a northern province of Vietnam in 2020