bluuebunny/crossref_metadata_2025 huggingface dataset:
COMBINATION OF ENVIRONMENTAL FACTORS INTO LAND USE PLANNING IN MO DUC DISTRICT - QUANG NGAI PROVINCE
Authors: ĐẠI GÁI ĐINH , THỊ DUNG NGUYỄN
Published: January 2021

Land-use planning is a strategy of appropriately managing the use of land resources. However, there would be numerous factors derived from nature, economics and society potentially affecting implementation of the land use planning. Therefore, the sustainable use of land resources can only be achieved through a combination of economic, social and environmental factors into land-use planning. The assessment of the environmental status coupled with environmental matrix methods and scoring methods allows us to pick out investigated factors having most negative impact on land use and land use planning in Mo Duc - Quang Ngai. Thereby, the current study was conducted to incorporate the economic, social and environmental factors as well as introduce a multiple criteria approach into implementation of land use planning in the district.
THE CHANGE OF WATER QUALITY AND PHYTOPLANKTON COMMUNITY STRUCTURE IN THE THI VAI RIVER BEFORE AND AFTER THE VEDAN DEEDS
Authors: THANH LƯU PHẠM
Published: January 2021

The change of water quality and phytoplankton community structure in the Thi Vai River before and after the Vedan deeds was investigated. Canonical correspondence analysis (CCA) was applied to investigate the main environmental factors governing planktonic communities. Results showed that the Thi Vai River was seriously contaminated by discharged waste water from Vedan’s factories. The high concentration of ammonium and orgarnic comtaminants have caused low dissolved oxygen in the water. This condition has lead favorable for harmful cyanobacterial species growth. After Vedan stopped its release, water quality in term of DO, NH4+, NO3- and PO43- in the Thi Vai River has been improved. This improvement has lead to change the phytoplanktonic structure from harmful cyanobacterial species to useful diatom species that are primary producers of food for other aquatic animals.
FLUORESCENCE DETECTION OF MELAMINE BASE ON FUNCTIONALIZED GRAPHENE OXIDE
Authors: NGUYEN VAN TRONG , TRAN THANH THUY , VAN THANH KHUE , CONG NGUYEN THANH
Published: January 2021

In this study, we report a new strategy to detect melamine. We present a sensitive and selective fluorescent aptasensor for detection melamine based on graphene oxide (GO) and SYBR Green I. Our strategy utilizes the efficient quenching ability of GO and the different interaction intensity of aptamer, aptamer/melamine complex with GO which directly induces the fluorescence intensity change. The results of experiment showed that, with the reaction mixture consisted of 1×NEBuffer 2, 80 nM T55, 2×SG and different concentration of melamine, the fluorescence of SYBR Green I decreases as the concentration of melamine decreasing. In addition, some conditions and working curve of melamine are established with the concentration of range from 1 nM to 200 nM. Linear regression analysis of detection data yielded the following equation: y = 176.66 + 1.68 x, where y and x denoted the fluorescence peak intensity and melamine concentration, respectively. The peak intensity showed a linear correlation to the concentration of melamine in the range of 10 to 200 nM. The result further demonstrated that the fluorescence recovery was attributed to the formation of between double-stranded (dsDNA) structure by the specific interaction dsDNA and SYBR Green I (SG). Therefore, the GO-based biosensing platform is feasible to be used to selecting for detection melamine. This method provides a simple, rapid and high-throughput method for detection melamine and it could be widely applied to detect small molecules, other proteins and DNAs with specific designed oligonucleotides because of its excellent sequence-independent property.
PRODUCTION OF POLYCLONAL ANTIBODIES FOR DETECTING HUMAN TYPE 2 TRANSGLUTAMINASE VARIANTS IN COLON CANCER
Authors: BUU TRAN GIA , HUYEN TRAN THI , VIET PHAM TAN , THI DIEU NGUYEN HANH
Published: January 2021

Type 2 transglutaminase (TGM2) is a multifunctional ubiquitous protein, involving in protein cross-linking, apoptosis, and cell differentiation. Recently, some reports have suggested that TGM2 expression is a potential prognostic marker, and often associates with advanced stages of disease, metastatic spread, as well as drug resistance in many cancer cell lines although its primary function is unknown. To elucidate the role of TGM2 in cancer, the expression profile of the TGM2 need to be examined. In this study, new polyclonal antibodies detecting four TGM2 variants encoding protein from ENSEMBL database are produced and their specificities are confirmed by western blot analysis with E.coli overexpressing TGM2-002 protein, HEK293T cells overexpressing TGM2-S protein and human colon cancer samples. Western blot data showed that these antibodies could detect not only TGM2-002 in E. coli overexpressing TGM2-002 but also smaller molecular weight protein (about 62 kDa) in HEK293T overexpressing TGM2-S cells which was further confirmed by MALDI-TOF analysis. We found that both TGM2-1 and TGM2-4 antibodies could detect the full length TGM2-002 protein in colon cancer samples. Furthermore, in normal sample, we found that majority of TGM2-002 protein existed in membrane fraction but not in total lysate whereas TGM2-002 protein was found in both total lysate and membrane fraction in colon cancer samples.
VIỆC SỬ DỤNG CÁC LOẠI LỖ TRONG LIÊN KẾT BU LÔNG CƯỜNG ĐỘ CAO TRONG XÂY DỰNG CẦU THÉP THEO 22TCN 272-05
Authors: PHAN ĐỖ CAO , ĐIỀM NGUYỄN ĐĂNG
Published: January 2021

Theo tiêu chuẩn thiết kế cầu 22TCN 272-05, liên kết bu lông cường độ cao chỉ được phép sử dụng lỗ tiêu chuẩn. Tuy nhiên, trong thực tế thi công, nhiều trường hợp đơn vị thi công khoan lỗ sai quy cách và không được phép sử dụng theo tiêu chuẩn. Bài báo này đề xuất sử dụng các loại lỗ trong liên kết bu lông cường độ cao dựa trên phân tích ứng suất cục bộ tại mép lỗ bằng phương pháp phần tử hữu hạn.
GALLOPING INSTABILITY ANALYSIS OF A CABLE-DAMPER SYSTEM
Authors: CUNG NGUYEN HUY , PHAN DO CAO
Published: January 2021

Viscous dampers are used widely to mitigate cable vibrations cable-stayed bridges. A damper attached to a stay cable leads to complex modes. The complexity can highly affect the aeroelastic stability of the cable. A galloping instability analysis of cable with an attached damper will be presented. A numerical example points out errors of conventional galloping analysis. The complexity of the mode shapes leads the cable being more unstable than ignoring it by treating the mode shapes as real.
BƯỚC ĐẦU ĐÁNH GIÁ KHẢ NĂNG SỬ DỤNG RFCC KHÔNG NGHIỀN LÀM PHỤ GIA TRONG SẢN XUẤT XI MĂNG
Authors: DUNG ĐỖ DOÃN , HƯNG BÙI ĐĂNG , DƯƠNG NGUYỄN PHÚC THUỲ , NGÂN TRẦN THỊ PHÚC , QUỐC LAI TRUNG
Published: January 2021

Trong thời gian tới ở Việt Nam, khi có nhiều nhà máy lọc dầu đi vào hoạt động, sẽ có một lượng lớn xúc tác đã qua sử dụng- gọi tắt là “RFCC” sẽ được thải ra, đây sẽ là một thách thức trong công tác quản lý môi trường. Nghiên cứu này đánh giá khả năng tái sử dụng RFCC không nghiền (RFCC-KN) làm chất phụ gia cho các loại xi măng đang được sản xuất tại Việt Nam bao gồm OPC, PBC30, PBC40 và PCB50. Kết quả thu được cho thấy RFCC-KN có tính chất lý-hóa tương tự như tro bay, một loại chất phụ gia đang được sử dụng rộng rãi trong sản xuất xi măng. RFCC-KN có thể phối trộn ở các tỉ lệ khác nhau để tạo ra nhiều loại xi măng. Xi măng OPC có thể phối trộn với RFCC-KN với tỉ lệ khối lượng đến 30% để tạo PCB40. Đối với các loại xi măng PCB, tỉ lệ thay thế của RFCC-KN là 20% và 10% tương ứng với PCB50 và PCB30. Và việc sử dụng RFCC-KN có thể giúp giảm chi phí sản xuất 1 tấn xi măng từ 6 đến 19%.
CÁC YẾU TỐ ẢNH HƯỞNG ĐẾN Ý ĐỊNH MUA THỰC PHẨM HỮU CƠ CỦA NGƯỜI TIÊU DÙNG THÀNH PHỐ HỒ CHÍ MINH DỰA TRÊN MÔ HÌNH S-O-R
Authors: SƠN LÊ HỒNG
Published: January 2021

Nghiên cứu này dựa trên mô hình cải tiến (S-O-R) nhằm nhận dạng và đo lường ảnh hưởng của các yếu tố là hàm lượng dinh dưỡng, hàm lượng tự nhiên, bảo vệ hệ sinh thái, hấp dẫn giác quan, giá, thái độ vị lợi và thái độ hưởng thụ đối với ý định mua thực phẩm hữu cơ của người tiêu dùng Tp.Hồ Chí Minh. Dựa trên kiểm nghiệm mô hình cấu trúc với bộ dữ liệu thu thập từ 289 người tiêu dùng; kết quả nghiên cứu cho thấy thái độ hưởng thụ và thái độ vị lợi có tác động tích cực và trực tiếp đến ý định mua của người tiêu dùng, còn các yếu tố hàm lượng dinh dưỡng, hàm lượng tự nhiên, bảo vệ hệ sinh thái, hấp dẫn giác quan có tác động tích cực và giá có tác động tiêu cực lên thái độ vị lợi và thái độ hưởng thụ. Nghiên cứu này giúp cho những người làm tiếp thị và thực hiện chính sách hiểu rõ phải làm thế nào để người tiêu dùng hình thành ý định mua thực phẩm hữu cơ.
ỨNG DỤNG MÔ HÌNH CHẤP NHẬN CÔNG NGHỆ (TAM) - TRƯỜNG HỢP NGHIÊN CỨU VỀ Ý ĐỊNH SỬ DỤNG ỨNG DỤNG YÊU CẦU XE CỦA KHÁCH HÀNG TẠI THÀNH PHỐ BIÊN HÒA
Authors: NHÂN PHAN TRỌNG , THƯƠNG PHAN THỊ SONG , VI HỒ TRÚC
Published: January 2021

Nghiên cứu này được tác giả ứng dụng lý thuyết nền từ mô hình chấp nhận công nghệ TAM (Technology Acceptance Model) và kiểm định thực nghiệm cho lĩnh vực ứng dụng trên thiết bị di động. Trong đó, khám phá mới của tác giả là việc đề xuất bổ sung hai thang đo động lực thụ hưởng và điều kiện thuận lợi trong kiểm định về ý định hành vi dựa trên số liệu khảo sát 476 khách hàng cả hai giới tính, ở các độ tuổi và nghề nghiệp khác nhau tại địa bàn thành phố (TP) Biên Hòa. Kết quả nghiên cứu cho thấy bên cạnh hai thang đo trong mô hình TAM tương quan thuận đến ý định thì hai thang đo động lực thụ hưởng và điều kiện thuận tiện cũng có quan hệ tuyến tính và tác động khá cao đến ý định sử dụng ứng dụng yêu cầu xe của khách hàng.
CĂNG THẲNG KINH TẾ, TÍNH VỊ CHỦNG VÀ ĐÁNH GIÁ SẢN PHẨM ẢNH HƯỞNG ĐẾN SỰ KHÔNG SẴN LÒNG MUA HÀNG HÓA NGOẠI NHẬP CỦA NGƯỜI TIÊU DÙNG TP. HỒ CHÍ MINH
Authors: PHÚC TRẦN HOÀI , KIÊN PHẠM XUÂN , XUÂN LÊ THỊ MINH
Published: January 2021

Nghiên cứu này nhằm khám phá tác động của Tính vị chủng, Căng thẳng kinh tế và Đánh giá sản phẩm lên sự không sẵn lòng mua hàng hóa Trung Quốc của người tiêu dùng Việt Nam. Dựa trên những sự kiện căng thẳng kinh tế gần đây giữa Việt Nam và Trung Quốc, nghiên cứu này đánh giá lòng tự hào dân tộc của người Việt Nam và sự không sẵn lòng mua hàng hóa Trung Quốc của họ như thế nào. Dựa trên dữ liệu thu thập từ 248 khách hàng, kết quả phân tích mô hình cấu trúc tuyến tính cho thấy sự không sẵn lòng mua hàng hóa Trung Quốc của người tiêu dùng Việt Nam chịu tác động của ba yếu tố là Căng thẳng kinh tế, Tính vị chủng và Đánh giá sản phẩm. Nghiên cứu này có thể hữu ích cho các doanh nghiệp Việt Nam trong việc phát triển các chiến lược kinh doanh và tiếp thị, đặc biệt là các doanh nghiệp nhập khẩu hoặc phân phối các hàng hóa Trung Quốc tại thị trường Việt Nam.
Two-sources randomness extractors in finite fields and in elliptic curves
Authors: Tchapgnouo Hortense Boudjou , Ciss Abdoul A. , Sow Djiby , Kolyang D.T.
Published: January 2021

We propose two-sources randomness extractors over finite fields and on elliptic curves that can extract from two sources of information without consideration of other assumptions that the starting algorithmic assumptions with a competitive level of security. These functions have several applications. We propose here a description of a version of a Diffie-Hellman key exchange protocol and key extraction.

Nous proposons des extracteurs d'aléas 2-sources sur les corps finis et sur les courbes elliptiques capables d'extraire à partir de plusieurs sources d'informations sans considération d'autres hypothèses que les hypothèses algorithmiques de départ avec un niveau de sécurité compétitif. Ces fonctions possèdent plusieurs applications. Nous proposons ici une version du protocole d'échange de clé Diffie-Hellman incluant la phase d'extraction.
Efficient controller synthesis of multi-energy systems for autonomous domestic water supply
Authors: NZEBOP NDENOKA Gérard , Simeu Emmanuel , Alhakim Rshdee
Published: January 2021

The continuous development of ICT facilitates the emergence and rapid proliferation of a wide variety of low-cost processors for the execution of programs in complex embedded applications. In this paper, the study explores the possibility to benefit from this wealth of computing capacity at a reasonable cost to solve concrete problems encountered in implementation of sustainable development processes, particularly in water and energy supply . . . We are focusing autonomous water supply in buildings of several floors using several tanks supplied by several sources of water and pumping energy, based on a multilevel hierarchical priority access to water. The first problem is to propose pumping devices and a switching process between power sources, associated to an architectural structure guaranteeing significant reduction of pumping energy. The second problem is the system controller realization. For this, we have proposed a generic architecture justified by gains in potential energy. We also propose an automatic generation tool of control programs for different microprocessor targets taken from the functional design specification of the system given in a Grafcet form. To put them in evidence, we describe at the end a case study.

Le développement vertigineux des TIC favorise l’émergence et la prolifération rapide d’une grande variété de processeurs à bas coût destinés à l’exécution de programmes embarqués dans des applications complexes. Dans ce papier, l’étude explore la possibilité de tirer profit de cette profusion de capacité de calcul à coût raisonnable pour résoudre des problèmes concrets que l’on rencontre dans la mise en place de processus de développement durable, notamment ceux liés à l’approvisionnement en eau et en énergie . . . Nous visons l’étude d’approvisionnement en eau autonome des bâtiments à plusieurs étages, en utilisant plusieurs citernes de stockage approvisionnées par plusieurs sources d’eau et d’énergie de pompage, basée sur plusieurs niveaux hiérarchisés de priorité d’accès à l’eau. Le premier problème est de proposer des dispositifs de pompage et un processus de commutation entre les sources d’énergie, associé à une structure architecturale garantissant une réduction significative de l’énergie de pompage. Le second problème est la réalisation du contrôleur. Pour cela, nous proposons une architecture générique justifiée par des gains d’énergie potentielle. Nous proposons aussi un outil de génération automatique de programmes de contrôle pour différentes cibles à microprocesseur à partir d’une spécification fonctionnelle sous la forme d’un Grafcet. Pour les mettre en évidence, nous décrivons à la fin un cas d’étude.
A self-stabilizing algorithm for a hierarchical middleware self-adaptive deployment : specification, proof, simulations
Authors: Faye Maurice-Djibril , Caron Eddy , Thiare Ousmane
Published: January 2021

ABSTRACT. An effective solution to deal with this dynamic nature of distributed systems is to implement a self-adaptive mechanism to sustain the distributed architecture. Self-adaptive systems can autonomously modify their behavior at run-timein response to changes in their environment. Our paper describes the self-adaptive algorithm that we developed for an existing middleware. Once the middleware is deployed, it can detects a set of events which indicate an unstable deployment state. When an event is detected, some instructions are executed to handle the event. We have proposed a sketch proof of the self-stabilizing property of the algorithm. We have designed a simulator to have a deeper insights of our proposed self-adaptive algorithm. Results of our simulated experiments validate the safe convergence of the algorithm.

RÉSUMÉ.Dans cet article, nous nous intéressons aux moyens de rendre le déploiement d’un intergiciel auto-adaptatif. Le type d’intergiciel que nous avons considéré ici est hiérarchique (structure de graphe) et distribué. Les infrastructures de grilles/cloud étant dynamiques (perte et ajout de nœuds),un déploiement statique n’est pas la solution idéale car en cas de panne, il est souvent nécessaire de reprendre tout le processus de déploiement; or cette opération est très coûteuse. Nous avons donc proposé un algorithme auto-stabilisant pour que l’intergiciel puisse retrouver un état stable sans intervention extérieure, au bout d’un temps fini, lorsqu’il est confronté à des pannes transitoires. Pouravoir une idée plus précise des caractéristiques de l’algorithme, nous avons conçu un simulateur. Lesrésultats des simulations montrent qu’un déploiement, sujet à des pannes transitoires, s’auto-adapte.
Classification by split and merge technique for the detection of vascular retinopathies
Authors: Assogba Kokou , Bouaoune Yasmina , Bunel Philippe
Published: January 2021

Dans cet article, nous proposons une nouvelle approche d'analyse de forme pour la détection des rétinopathies vasculaires. La méthode procède à la classification des vaisseaux et quantifie la modification de leur tortuosité sur les images d'angiographie rétinienne en fluorescence. La classification est basée sur une technique de division/fusion. Deux classes sont définies: artère/veine et artériole/veinule. Dans une séquence d'images, les vaisseaux classifiés sont mis en correspondance. La quantification consiste à comparer la tortuosité des vaisseaux classifiés correspondants. La tortuosité est définie par la valeur de l'excentricité déterminée avec les moments invariants 2D d'ordre 2. La méthode est appliquée aux images d'angiographie rétinienne en fluorescence de patients diabétiques et drépanocytaires.

In this paper, we present a novel approach of quantification of retinal vascular shape changes for detecting vascular retinopathies. The method classifies vessels and quantifies their tortuosity changes in fluorescein angiographic images. The classification approach is based on a split and merge technique. Two classes of vessel are defined: artery/vein and arteriole/veinlet. In a sequence of images, we form correspondence of classified vessels. Quantifying classified vessels consists of comparing the correspondent tortuosity. We use eccentricity to define tortuosity. Eccentricity computation is based on 2D moment invariant techniques. The method is applied to images of patients suffering of diabetes and sickle cell hemoglobin C disease.
Inverse Problem: Stability for the aligned magnetic field by the Dirichlet-to-Neumann map for the wave equation in a periodic quantum waveguide
Authors: Youssef Mejri
Published: January 2021

Dans ce papier, on a prouvé une estimation de stabilité pour le problème inverse de dé-termination du champ magnétique dans l'équation des ondes donné sur un domaine non borné à partir de l'opérateur de Dirichlet-to-Neumann. On a montré un résultat de stabilité pour ce problème inverse, dont la démonstration est basée sur la construction de solutions optique géométrique pour l'équation des ondes avec un potentiel magnétique 1-périodique. ABSTRACT. We consider the boundary inverse problem of determining the aligned magnetic field appearing in the magnetic wave equation in a periodic quantum cylindrical waveguide from boundary observations. The observation is given by the Dirichlet to Neumann map associated to the wave equation. We prove by means of the geometrical optics solutions of the magnetic wave equation that the knowledge of the Dirichlet-to-Neumann map determines uniquely the aligned magnetic field induced by a time independent and 1-periodic magnetic potential. We establish a Hölder-type stability estimate in the inverse problem.
Solvability of Mixed Problems With Integral Condition for Singular Parabolic Equations
Authors: Almomani Raid
Published: January 2021

In this paper we proved the existance and uniqness of strong generalized solution of mixed problems wih integral condition for singular parabolic equaions depending on a theorem proved in [1] in which a priori estimaion of the solution for such problems was derived.
Extraction of Association Rules for the Prediction of Missing Values
Authors: Jami Sylvie , Jen Tao-Yan , Laurent Dominique , Loizou Georges , Sy Oumar
Published: January 2021

Missing values in databases have motivated many researches in the field of KDD, specially concerning prediction. However, to the best of our knowledge, few appraoches based on association rules have been proposed so far. In this paper, we show how to adapt the levelwise algorithm for the mining of association rules in order to mine frequent rules with a confidence equal to 1 from a relational table. In our approach, the consequents of extracted rules are either an interval or a set of values, according to whether the domain of the predicted attribute is continuous or discrete.

La présence de valeurs manquantes ou valeurs nulles dans les bases de donnnées a suscité de nombreuses recherches dans le domaine de la découverte des connaissances, notamment en ce qui concerne la prédiction. Cependant, à notre connaissance, peu de telles approches utilisent les règles d'association pour la prédiction des valeurs manquantes. Dans cet article, il est montré comment adapter les différents concepts et algorithmes par niveau liés aux règles d'association, afin d'obtenir des règles fréquentes et de confiance 1, permettant la prédiction de valeurs manquantes dans une table relationnelle. La particularité des règles extraites dans notre approche est que leurs conséquents se présentent sous la forme d'intervalles ou d'ensembles de valeurs, selon que le domaine de l'attribut sur lequel les valeurs sont prédites est soit continu soit discret.
A Water Supply Optimization Problem for Plant Growth Based on GreenLab Model
Authors: Wu Lin , De Reffye Philippe , Hu Bao-Gang , Le Dimet François-Xavier , Cournède Paul-Henry
Published: January 2021

GreenLab is a structural-functional model for plant growth based on multidisciplinary knowledge. Its mathematical formalism allows dynamic simulation of plant growth and model analysis. A simplified soil water balance equation is introduced to illustrate the interactions and feedbacks between the plant functioning and water resources. A water supply optimization problem is then described and solved: the sunflower fruit weight is optimized with respect to different water supply strategies in a theoretical case. Intuitive searching method and genetic algorithms are used to solve this mixed integer nonlinear problem. The optimization results are analyzed and reveal possible agronomic applications.

GreenLab est un modèle structure-fonction de croissance des plantes. Son formalisme mathématique permet la simulation dynamique de la croissance et l'analyse du modèle. Dans cet article est introduit une équation bilan de l'eau dans le sol afin de décrire les interactions entre la croissance de la plante et les ressources en eau disponibles. Un problème d'optimisation des apports d'eau au cours de la croissance est présenté et résolu par la méthode de recherche intuitive et par les algorithmes génétiques: le poids du fruit de tournesol est maximisé en fonction dedifférentes stratégies d'apports d'eau, pour une quantité d'eau totale identique. Le formalisme présenté est intéressant en ce qu'il ouvre la voieà d'importantes applications en agronomie.
Mise en oeuvre de tests unitaires dans un contexte de programmation eXtrème répartie
Authors: Lokpo Ibrahim , Babri Michel , Padiou Gérard
Published: January 2021

eXtreme Programming (XP) is a methodology based on principles and practices for quickly developing software. However this approach requires the programmers to be co-located. Many research projects investigate how to extend XP to a distributed environment. However the challenge is to carry out the XP approach without conflicting with the distributed constraints. Our work takes place in this way. More precisely, we propose an extension based on assistance for supporting distributed unit testing, one of the key principles of XP methodology.

La programmation eXtrème dite XP (eXtreme Programming) est une méthodologie efficace de développement rapide de logiciels qui exige que les membres d'une équipe de développeurs soient physiquement proches les uns des autres. Des travaux de recherche tentent d'étendre les principes de cette méthodologie à un contexte réparti. Le défi est alors de préserver les qualités fondamentales de l'approche tout en s'affranchissant de la contrainte de proximité physique des développeurs. Notre travail s'inscrit dans cette logique. De façon plus précise, nous proposons de fonder cette extension de XP à un environnement réparti sur l'assistance à la réalisation des tests unitaires, pierre angulaire de la méthodologie XP.
Suite d’ensembles partiellement ordonnés
Authors: Sadi Bachir
Published: January 2021

This work is to study an order D(P) on maximal antichains of a given order. D(P) is an order included in the order which defines the Lattice of maximal antichains AM(P), introduced by R.P. Dilworth, in 1960. In [3], T.Y. Kong and P. Ribenboim have proved that there exists an integer i such that Di(P) is a chain, where Di(P)=D(D(…D(P))), i times. We find the smallest i, noted cdev(P) such that Di(P) is a chain for some particular classes of orders and we approximate this parameter in the general case of order.

Ce travail porte sur le développement d’un ordre D(P) sur les antichaînes maximales d’un ordre donné. L’ordre développé D(P) est inclus dans le Treillis des antichaînes maximales AM(P), introduit par R.P. Dilworth, en 1960. Dans [3], T.Y. Kong et P. Ribenboim ont montré qu’il existe un entier naturel i tel que Di(P) est une chaîne, où Di(P)=D(D(…D(P))), i fois. On note cdev(P) le plus petit i tel que Di(P) est une chaîne. Nous trouvons cdev(P) pour quelques classes particulières d’ordres et nous faisons une approche de ce paramètre dans le cas d’un ordre quelconque.
SenPeer : un système pair-à-pair de médiation de données
Authors: Faye David C. , Nachouki Gilles , Valduriez Patrick
Published: January 2021

In this article we present SenPeer, a new Peer-to-Peer data management system allowing data sharing among experts working on the development of the Senegal river in a decentralized and lexible fashion. SenPeer has a Super-Peer network topology based on an organization of peers in semantic domains and in which peers can contribute XML documents, relational or object databases. Each peer exports its data in a common formalism which has a graph structure semantically enriched with a set of keywords in order to guide mappings discovery. Mappings discovery relies on a set of fuzzy similarity measures. Moreover they allow the establishement of a semantic topology that is independent of the underlying network topology which is the basis for intelligent query routing.

Dans cet article nous présentons SenPeer, un nouveau système pair-à-pair de gestion de données distribuées permettant le partage décentralisé et flexible de données relatives la mise en valeur du fleuve Sénégal. SenPeer est un réseau de type Super-Pair reposant sur une organisation des pairs en domaines sémantiques et dans lequel les pairs peuvent publier des bases de données relationnelles ou objets ou des documents XML. Chaque pair exporte ses données dans un formalisme pivot commun qui a une structure de graphe enrichi sémantiquement avec des mots-clés destinés à guider la découverte des correspondances entre les éléments des schémas. Ces correspondances sont découvertes grace à un ensemble de mesures de similarités floues. De plus elles permettent l'établissement d'un réseau sémantique à coté de la typologie physique. pouvant servir de support un à routage intelligent des requêtes.
Décomposition de domaine pour un milieu poreux fracturé : un modèle en 3D avec fractures
Authors: Amir Laila , Kern Michel , Roberts Jean E. , MARTIN Vincent
Published: January 2021

In this paper, we are interested in modeling the flow of a single phase fluid in a porous medium with fractures, using domain decomposition methods. In the proposed approach, the fracture is regarded as an active interface, the transmission conditions and the exchanges between the rock and the fracture taking into account the flow in the fracture. The problem to be solved is then a non standard interface problem which takes into account the flow in the fractures.
Méthode d'agrégation des variables appliquée à la dynamique des populations
Authors: Auger Pierre , El Abdllaoui Abderrahim , Mchich Rachid
Published: January 2021

We present the method of aggregation of variables in the case of ordinary differential equations. We apply the method to a prey - predator model in a multi - patchy environment. In this model, preys can go to a refuge and therefore escape to predation. The predator must return regularly to his terrier to feed his progeny. We study the effect of density-dependent migration on the global stability of the prey-predator system. We consider constant migration rates, but also density-dependent migration rates. We prove that the positif equilibrium is globally asymptotically stable in the first case, and that its stability changes in the second case. The fact that we consider density-dependent migration rates leads to the existence of a stable limit cycle via a Hopf bifurcation.

Nous présentons les grandes lignes de laméthode d'agrégation des variables dans les systèmes d'équations différentielles ordinaires. Nous appliquons laméthode à un modèle proie-prédateur spatialisé. Dans ce modèle, les proies peuvent échapper à la prédation en se réfugiant sur un site. Le prédateur doit aussi retourner régulièrement dans son terrier pour nourrir sa progéniture. Nous étudions les effets de migration dépendant de la densité des populations sur la stabilité globale du système proie-prédateur. Nous considérons des taux de migration constants, puis densité-dépendants. Dans le cas de taux constants il existe un équilibre positif toujours stable alors que dans le cas de taux de migration densité-dépendants, il existe un cycle limite stable via une bifurcation de Hopf.
Système d'Information Intégré Adaptatif sous Web pour la gestion et la modélisation des ressources hydriques
Authors: El Dabaghi F. , Bechchi M. , Henine H.
Published: January 2021

This work presents the Adaptative Integrated Information System under Web (AIISW) for the management of hydrous resources. The AIISW is a natural extension of the IISW-WADI towards an adaptative and customised architecture according to the user profile or the context of use including : a research and indexation engine system, simulators, a GIS and meshing editors as well as graphic viewers. This AIISW allows on the one hand to manage in an automatic way data of simulators and on the other hand to exploit and calibrate eventually in real time the results of these simulations by corroborating them with extracted or identified parameters.

Ce travail présente le Système d'Information Intégré Adaptatif sous Web (SIIAW) pour la gestion des ressources hydriques. Le SIIAW est une extension naturelle du S2IW-WADI vers une architechture adaptative et personnalisée en fonction de l'utilisateur et du contexte d'utilisation incluant: un système de recherche et d'indexation, des codes de simulations, un SIG et des mailleurs ainsi que des visualiseurs graphiques. Ce SIIAW permet ainsi d'une part de manipuler de manière automatique les données des simulateurs et d'autre part d'exploiter et de caler éventuellement en temps réel les résultats de ces simulations en les corroborant avec des paramètres extraits ou identifiés.
Ondes dans les milieux poroélastiques - Analyse du modèle de Biot
Authors: Ezziani Abdelaaziz
Published: January 2021

We are interested in the modeling of wave propagation in poroelastic media. We consider the biphasic Biot's model. This paper is devoted to the mathematical analysis of such model : existence and uniqueness result, energy decay result and the calculation of an analytical solution.

Nous nous intéressons à la modèlisation de la propagation d'ondes dans les milieux poroélastiques. Nous considérons le modèle bi-phasique de Biot. Ce papier est consacré à l'analyse mathématique de ce modèle : résultats d'existence et d'unicité, décroissance de l'énergie et le calcul d'une solution analytique.
Résolution d'un Problème de Cauchy en EEG
Authors: El-Badia Abdellatif , Farah Maha , Ha-Duong Tuong , Pavan Vincent
Published: January 2021

This paper talks about the resolution of the Cauchy problem thats appears in the localization of epileptic sources on Electro-Encephalo-Graphy (EEG). We treat specially the problem of estimating Cauchy data over the layer of the brain, knowing only the ones on the scalp measured by EEG. As a method of resolution, we choose an alternating iteratif algorithm rst proposed by Kozlov, Mazjya and Fomin. In this paper, we study numerically this method in three dimensions. We give also some numerical examples.

Dans cet article, nous traitons un problème de Cauchy dans le cadre de la localisation des sources épileptiques en Electro-Encéphalo-Graphie (EEG). Plus particulièrement, il s'agit du problème de construction des données de Cauchy sur la surface du cerveau à partir des données du potentiel mesuré par l'EEG à la surface de la tête. Notre résolution est basée sur un algorithme itératif alternatif initialement proposé par Kozlov, Mazjya et Fomin. Nous présentons dans ce papier l'étude umérique de cette méthode que nous avons implémentée en trois dimensions. Nous donnons également des applications et des résultats numériques.
Spectral Procedure with Diagonalization of Operators for 2D Navier-Stokes and Heat Equations in Cylindrical Geometry
Authors: El Guarmah El Mahdi , Cheddadi Abdelkhalek , Azaier Mejdi
Published: January 2021

We present in this paper a spectral method for solving a problem governed by Navier-Stokes and heat equations. The Fourier-Chebyshev technique in the azimuthal direction leads to a system of Helmholtz equations. The Collocation-Chebyshev method in the radial direction has been used for the simulation of these equations. The Crank-Nicholson scheme is employed to solve the Helmholtz systems obtained for wide ranges of parameters, and its efficiency is considerably improved by diagonalization of the obtained operators. The results are in a very good agreement with the experimental data available in the literature.

Dans ce papier, une méthode spectrale est appliquée à un problème gouverné par les équations de Navier-Stokes couplées à celle de la chaleur pour un fluide visqueux incompressible à nombre de Prandtl fini, confiné dans un espace annulaire. La technique de Fourier-Chebyshev dans la direction azimutale est mise en oeuvre et mène à un système d'équations couplées du type Helmholtz. La méthode de Collocation-Chebyshev dans la direction radiale a été employée pour la simulation de ces équations. Le schéma de Crank-Nicholson est implémenté pour résoudre les équations de Helmholtz obtenues pour une large gamme de paramètres, et l'efficacité de la procédure de calcul est considérablement améliorée par diagonalisation des opérateurs obtenus. Les résultats sont dans un très bon accord avec les données expérimentales disponibles dans la littérature.
An introduction to the topological asymptotic expansion with examples
Authors: Fehrenbach Jérôme , Masmoudi Mohamed
Published: January 2021

To find an optimal domain is equivalent to look for Its characteristic function. At first sight this problem seems to be nondifferentiable. But it is possible to derive the variation of a cost function when we switch the characteristic function from 0 to 1 or from 1 to 0 a small area. Classical and two generalized adjoint approaches are considered in this paper. Their domain of validity is given and Illustrated by several examples. Using this gradient type Information, It is possible to build fast algorithms. Generally, only one Iteration Is needed to find the optimal shape.

Trouver un domaine optimal est équivalent à la recherche de sa fonction caractéristique. A première vue, ce problème semble non différentiable, mais Il est possible de calculer la variation de la fonction coût lorsque la fonction caractéristique passe de 1 à 0 ou de 0 à 1 dans une région de petite taille. On s’appuiera sur une approche adjointe classique et deux généralisations de cette méthode. Le domaine de validité de ces différentes approches est donné et illustré par différents exemples. Cette Information de type gradient permet de construire des algorithmes très efficaces: en général, une seule Itération suffit pour trouver le domaine optimal.
Problème de contrôle optimal frontière pour l'équation de la chaleur : Approche variationnelle et pénalisation
Authors: Metoui H.
Published: January 2021

Our goal is to give a detailed analysis of an optimal control problem where the control variable is a rather boundary condition of Dirichlet type in L². We focus on establishing an appropriate variationnel approach to the optimal problem. We use the penalization method for the boundary control problem and we study the convergence between the penalized and the non-penalized boundary control problem. A numerical result is reported on to validate the convergence.

Notre objectif est d'analyser un problème de contrôle frontière de l'équation de la chaleur définie avec une condition de Dirichlet de carré intégrable. Nous proposons une approche variationnelle adéquate au problème de contrôle frontière. Afin de prendre en compte la condition de Dirichlet, nous adoptons une procédure de pénalisation et nous étudions la convergence de la solution optimale pénalisée vers celle du problème initial. Un test numérique est discuté pour valider la convergence.
Schéma SRNHS Analyse et Application d'un schéma aux volumes finis dédié aux systèmes non homogènes
Authors: SAHMIM Slah , Benkhaldoun Fayssal
Published: January 2021

This article is devoted to the analysis, and improvement of a finite volume scheme proposed recently for a class of non homogeneous systems. We consider those for which the corressponding Riemann problem admits a selfsimilar solution. Some important examples of such problems are Shallow Water problems with irregular topography and two phase flows. The stability analysis of the considered scheme, in the homogeneous scalar case, leads to a new formulation which has a naturel extension to non homogeneous systems. Comparative numerical experiments for Shallow Water equations with sourec term, and a two phase problem (Ransom faucet) are presented to validate the scheme.

Cet article concerne l'analyse et l'application, d'un schéma proposé récemment por une classe de systèmes non homogènes. Nous considérons ceux pour lesquels le problème de Riemann correpondant admet une solution autosimilaire. Deux exemples importants de tels problèmes sont l'écoulement d'eau peu profonde au-dessus d'un fond non plat et les problèmes diphasiques. l'analyse de stabilité du schéma, dans le cas scalaire homogène, amène à une nouvelle écriture qui a une extension naturelle pour le cas non homogène. Des expériences numériques comparatives pour des équations de saint-Venant avec topographie variable, et un problème diphasique (Robinet de Ransom) sont présentés pour évaluer l'efficacité du schéma.
Discrétisation en temps par sous-domaine pour un problème d'advection en milieu poreux
Authors: Sboui Amel , Jérôme Jaffré
Published: January 2021

The aim of this paper is to present a method of time dicretisation which allows the use of different time steps in different subdomains. The advection equation is dicretised by an upwind scheme. The link between the time grids is accomplished in order that the scheme is conservative.

L'objet de cet article est de présenter une méthode de discrétisation en temps telle que des pas de temps différents sont utilisés dans différents sous-domaines en espace. L'équation d'advection est discrétisée par un schéma décentré amont. Le raccord entre les grilles en temps est réalisé de sorte que le schéma soit conservatif
Régularisation d'un problème d'obstacle bilatéral
Authors: Achachab B. , Zahi J. , Addou A.
Published: January 2021

The main objective of this work is the resolution of an bilateral obstacle problem by means of the regularization method.

Le but essentiel de ce travail est la résolution d'un problème d'obstacle bilatéral à l'aide d'une méthode de régularisation
Flood simulation via shallow water numerical model based on characteristic method
Authors: El Dabaghi F. , El Kacimi A. , Nakhlé B.
Published: January 2021

This work deals with the numerical simulation of flood waves propagation. This phenomena can be described by the non conservative form of shallow water or St-Venant equations, in water velocity-depht formulation (u,H). The numerical approximation of the model is based on the Characteristics method for the time discretization. The obtained steady system is of Quasi-Stokes type, and it is resolved by a preconditioned Uzawa conjugated gradient algorithm, combined to P1/P1 finite element for the spatial approximation. Some numerical results describing subcritical flow on various fluid domains are given.

Ce travail concerne la simulation numérique de la propagation des crues. Ce phénomène peut être décrit par les équations d'eau peu profonde ou de Saint-Venant, écrites sous forme non conservative en formulation vitesse-hauteur (u,H). L'approximation numérique du modèle repose sur la méthode des caractéristiques pour la discrétisation temporelle. Le système stationnaire obtenu est de type Quasi-Stokes, et il est résolu par un algorithme de gradient conjugué Uzawa préconditionné, basé sur la méthode des éléments finis P1/P1 pour l'approximation spatiale. Des résultats numériques concernant des simulations d'écoulements subcritiques dans plusieurs type de conduites sont présentés.
Motivic Pattern Extraction in Music, and Application to the Study of Tunisian Modal Music
Authors: Lartillo Olivier , Ayari Mondher
Published: January 2021

A new methodology for automated extraction of repeated patterns in time-series data is presented, aimed in particular at the analysis of musical sequences. The basic principles consists in a search for closed patterns in a multi-dimensional parametric space. It is shown that this basic mechanism needs to be articulated with a periodic pattern discovery system, implying therefore a strict chronological scanning of the time-series data. Thanks to this modelling global pattern filtering may be avoided and rich and highly pertinent results can be obtained. The modelling has been integrated in a collaborative pro ject between ethnomusicology, cognitive sciences and computer science, aimed at the study of Tunisian Modal Music.

Une méthodologie d'extraction automatique de motifs répétés dans des séquences temporelles est présentée, dédiée en particulier à l'analyse de séquences musicales. L'approche initiale consiste en une recherche de motifs fermés dans un espace paramétrique multidimensionnel. Il est montré que ce premier mécanisme doit être articulé avec un système de découverte de motifs périodiques, ce qui implique un parcours strictement chronologique de la séquence. Cette modélisation permet d'éviter un filtrage global des patterns, et donc d'obtenir des résultats présentant une richesse et une pertinence élevée. La modélisation a été intégrée au sein d'un projet collaboratif entre ethnomusicologie, sciences cognitives et informatique, dédié à l'étude de la musique modale tunisienne.
A Texture-based Method for Document Segmentation and Classification
Authors: Lin Ming-Wei , Tapamo Jules-Raymond , Ndovie Baird
Published: January 2021

In this paper we present a hybrid approach to segment and classify contents of document images. A Document Image is segmented into three types of regions: Graphics, Text and Space. The image of a document is subdivided into blocks and for each block five GLCM (Grey Level Co-occurrence Matrix) features are extracted. Based on these features, blocks are then clustered into three groups using K-Means algorithm; connected blocks that belong to the same group are merged. The classification of groups is done using pre-learned heuristic rules. Experiments were conducted on scanned newspapers and images from MediaTeam Document Database

Dans cet article nous présentons un modèle hybride de segmentation et classification du contenu d'images de documents. Chaque image est segmentée en trois types de régions: graphiques, textes et espaces. L'image de chaque document est subdivisée en blocs; pour chacun de ces blocs, cinq caractéristiques sont extraites de leur Matrice de Co-occurrence de leur niveaux de gris. Les blocs sont ensuite regroupés en trois classes en utilisant l'algorithme du K-means. Les blocs connectés sont fusionnés pour former un ensemble de régions homogènes. Des règles heuristiques sont ensuite utilisées pour donner un label à chacune des trois classes. Des expérimentations ont été effectuées avec des images scannées de journaux et des images de la base de données documentaire MediaTeam
A Word Game Support Tool Case Study
Authors: Botha T. , Kourie D.G. , Watson B.W.
Published: January 2021

This article reports on the approach taken, experience gathered, and results found in building a tool to support the derivation of solutions to a particular kind of word game. This required that techniques had to be derived for simple yet acceptably quick access to a dictionary of natural language words (in the present case, Afrikaans). The main challenge was to access a large corpus of natural language words via a partial match retrieval technique. Other challenges included discovering how to represent such a dictionary in a "semi-compressed" format, thus arriving at a balance that favours search speed but nevertheless derives a savings on storage requirements. In addition, a query language had to be developed that would effectively exploit this access method. The system is designed to support a more intelligent query capability in the future. Acceptable response times were achieved even though an interpretive scripting language, ObjectREXX, was used.

Cet article présente la méthode utilisée, l’expérience menée et les résultats obtenus dans le processus de construction d’un outil d'aide à la dérivation des solutions relatives à un type particulier de jeux de mots. Ceci requiert que des techniques soient dérivées pour un accès simple et rapide dans le dictionnaire des mots du langage naturel (l’Afrikaans pour le cas d’espèce). Le gros problème était d’accéder à un large corpus de mots du langage naturel à travers la technique d’identification de mots par extraction partielle. L’autre défi était de représenter un tel dictionnaire sous un format «semi-compressé», permettant ainsi de se trouver dans une situation qui améliore non seulement le temps de recherche dans le dictionnaire, mais aussi l’espace requis pour sa sauvegarde. De plus, un langage de requête, exploitant de façon effective la dite méthode d’accès devait être mise en oeuvre. Le système est conçu de façon à supporter dans le futur des requêtes plus intelligentes. Un temps de réponse acceptable a été obtenu bien qu'un langage interprétatif de Scripting (ObjREXX) ait été utilisé.