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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

An assessment of the level of independence of electoral management bodies and their effects on democratisation in africa: the case of Ghana and the Democratic Republic of Congo

Gabie, Carmel Tshamalamala 09 1900 (has links)
The basic problem in this study is to determine whether the electoral management body (EMB) in the Democratic Republic of Congo (DRC) is sufficiently independent and whether it complies with most of the criteria of an ideal independent EMB in order to conduct free and fair elections in the promotion of democracy in the DRC. However, an ideal type of an independent EMB is not easily realizable but Ghana’s electoral commission (EC) is widely regarded as a model of an independent EMB in Africa. Therefore, this study uses the EC as a workable ideal type of independent EMB that informs this study in assessing the Independent National Electoral Commission (CENI)’s level of independence. The study discovered that while the formal legal framework guarantee the independence of the CENI, it lacks practical independence due to certain factors which include the mode of appointment and composition of the body, the unstable security of tenure of its members, the negative influence of the judiciary, executive and the parliament over the functioning of the CENI, and the lack of adequate funding. The study argues that the composition of the CENI has to be depoliticized; its members should enjoy a strong security of tenure and the issue of political parties funding should be effective and handled by the CENI in order to enhance political competitiveness in the electoral process. An adequate funding should be timely realized so that the CENI carries out its work with autonomy. The judiciary, the parliament and the executive should support the growth of democracy in the DRC by allowing the CENI to work without the interference of any quarter. / African Centre for Arts, Culture and Heritage Studies / M.A. (African Politics)
412

The competence of the foreign representative in cross-border insolvency matters : a comparison between South Africa and Australia / Ella Mouton

Mouton, Ella January 2014 (has links)
The world is continuously becoming a smaller and smaller place. It has become a global community of sorts merely divided by imperceptible borders that are easily transversed by ever-evolving technological advances in the fields of business, travel, communication and such, each regulated by its own set of domestic laws and regulations. Hordes of South Africans immigrate to Australia annually due to, among others, economic and political uncertainty. These ex-patriots generally leave behind assets and creditors in South Africa whilst acquiring new ones wherever they choose to establish themselves. This serves as basis for potential future cross-border insolvency issues. Furthermore, entities such as companies trading internationally, and multinational companies with branches and offices in more than one state, have property and creditors in many different jurisdictions. Should such a company be liquidated, it would give rise to questions of jurisdiction, the procedures to be followed, the appointment of a liquidator(s) and the distribution of assets, to name a few. The absence of a universal cross-border insolvency law leaves room for much uncertainty and confusion. What is of importance for purposes of this research is to clarify all prevailing uncertainties regarding the rights and obligations of the foreign representative and the foreign creditor in cross-border insolvency matters. The foreign representative is the person or entity appointed to administer the reorganisation or liquidation of the insolvent debtor’s assets in a foreign proceeding. The inconsistency in cross-border insolvency regulations between South Africa and Australia has the consequence that there is no guarantee that a foreign creditor in one state will be treated the same as a foreign creditor in terms of the domestic laws of the other, as the Model Law aims to do. The situation would have been significantly less complicated had the South African Cross-Border Insolvency Act been in force at present and had Australia been designated as a state to which this Act would apply. In that case, the treatment of foreign representatives and foreign creditors would be of a reciprocal nature. This dissertation attempts, through an investigation of the South African and Australian domestic insolvency laws, to ascertain the position of the foreign representative and foreign creditors pre and post incorporation of the Model Law. Consequently this dissertation compares the legal positions of these parties in terms of South African and Australian national insolvency legislation. / LLM (Import and Export Law), North-West University, Potchefstroom Campus, 2014
413

The involvement and participation of student representative councils in co-operative governance in higher education institutions in South Africa

Moreku, Clement January 2014 (has links)
Thesis (Phd. (Education Management )) - Central University of Technology, Free State, 2014 / The dawn of democracy in South Africa resulted in an emphasis on the involvement and participation of stakeholders in decision-making processes. At public higher education institutions, involvement and participation were guaranteed by the enactment of the Higher Education Act 101 of 1997. This Act provides that co-operative governance should be practiced in the governance of public higher education institutions. Students are stakeholders in higher education institutions. This means that according to the Act, students ought to be represented in the governance of public higher education institutions. The representation of students in university governance became a new phenomenon in the democratic South Africa. This thesis explored the involvement and participation of student representative councils in the co-operative governance of South African higher education institutions. It evaluated the role and effect of SRCs in the co-operative governance of public higher education institutions in South Africa. Following the merging of these institutions, universities have multi campuses, all of which need to be represented in the universities Managements through SRCs. This study employed the QUAN-Qual (explanatory) mixed methods design which included the use of a questionnaire and in-depth, open-ended, semi-structured interviews. The sample for the study was made up of hundred and fifty-three respondents and nine interviewees from three types of South African higher education institutions. The quantitative part of this study investigated the nexus between the involvement and participation of SRCs in co-operative governance at public higher education institutions. The correlation between SRCs’ perception of participation and co-operative governance was also examined. The study also explored the SRCs’ perception of the implementation of co-operative governance at different universities types. The qualitative part of the study investigated perception of the nature of co-operative governance the SRCs at different universities. It also examined perceptions regarding whether participatory democracy was practiced at universities, v challenges experienced in the governance of universities and what the SRCs thought should be done to address those challenges. The study found that SRC members feel that they are both involved and also participate in the governance of public higher education institutions in South Africa. This was further enhanced by research hypotheses that revealed that there is a statistically significant relationship between the SRCs’ perception of their involvement and participation in university governance and their perception of the implementation of co-operative governance in the South African higher education institutions. Although SRC members feel that they are involved and that they participate in co-operative governance, interviews have revealed that they experience the following problems:  SRC members have annual budget deficits at their universities and as a result, they fail to fulfill their mandates by the student body.  SRCs find it difficult to deal with the challenges pertaining to multi-campus set-ups in their institutions.  The existence of student political structures contributes to ideological differences amongst SRC members. This affects effective student governance at universities.  The capacity building of SRC members at higher education institutions is not adequately addressed by managements of these institutions. The researcher recommends that it is important that HEIs adhere to the HE Act 101 of 1997, as amended. Adherence to the Act will ensure that there is compliance with the law and will minimise the chances for HEIs to be placed under administration. The managements of universities and SRCs need to co-operate in order to ensure that co-operative governance in HEIs is effectively implemented. Workshops and meetings are held at universities between SRCs and managements regarding issues of co-operative governance. SRCs need to involve themselves in national and international student activities in order for them to gain knowledge and skills about student governance. The researcher designed a multi-campus student governance model that will effectively deal with the challenges mentioned above.
414

The competence of the foreign representative in cross-border insolvency matters : a comparison between South Africa and Australia / Ella Mouton

Mouton, Ella January 2014 (has links)
The world is continuously becoming a smaller and smaller place. It has become a global community of sorts merely divided by imperceptible borders that are easily transversed by ever-evolving technological advances in the fields of business, travel, communication and such, each regulated by its own set of domestic laws and regulations. Hordes of South Africans immigrate to Australia annually due to, among others, economic and political uncertainty. These ex-patriots generally leave behind assets and creditors in South Africa whilst acquiring new ones wherever they choose to establish themselves. This serves as basis for potential future cross-border insolvency issues. Furthermore, entities such as companies trading internationally, and multinational companies with branches and offices in more than one state, have property and creditors in many different jurisdictions. Should such a company be liquidated, it would give rise to questions of jurisdiction, the procedures to be followed, the appointment of a liquidator(s) and the distribution of assets, to name a few. The absence of a universal cross-border insolvency law leaves room for much uncertainty and confusion. What is of importance for purposes of this research is to clarify all prevailing uncertainties regarding the rights and obligations of the foreign representative and the foreign creditor in cross-border insolvency matters. The foreign representative is the person or entity appointed to administer the reorganisation or liquidation of the insolvent debtor’s assets in a foreign proceeding. The inconsistency in cross-border insolvency regulations between South Africa and Australia has the consequence that there is no guarantee that a foreign creditor in one state will be treated the same as a foreign creditor in terms of the domestic laws of the other, as the Model Law aims to do. The situation would have been significantly less complicated had the South African Cross-Border Insolvency Act been in force at present and had Australia been designated as a state to which this Act would apply. In that case, the treatment of foreign representatives and foreign creditors would be of a reciprocal nature. This dissertation attempts, through an investigation of the South African and Australian domestic insolvency laws, to ascertain the position of the foreign representative and foreign creditors pre and post incorporation of the Model Law. Consequently this dissertation compares the legal positions of these parties in terms of South African and Australian national insolvency legislation. / LLM (Import and Export Law), North-West University, Potchefstroom Campus, 2014
415

台灣地方選舉

郎裕憲, Lang, Yu-Xian Unknown Date (has links)
現代民主政治,植基於地方自治;而地方自治之推行,則自選舉始。故朝野如何善事 地方選舉,使確屬賢能之士,出主庶政,為民服務;發言議壇,為民立法,民治成敗 ,關係至巨。 台省實施地方選舉,為國史上之首創,又時當日本專制統治五十一年之後,中央政府 甫行遷台,國難嚴重之際,其成敗得失,影響深遠,實不待言。著者之決心研究此問 題者,蓋亦在此。 考現代民主政治雖已成為家喻戶曉之名,詞,然為最難採行之政制。因其施行前必備 之先決條件,屈指難數。諸如:言論、集會、結社與宗教信仰等等之自由已否存在, 司法審判之獨立能否維持;國民之基本教育是否普及;國民之公共道德已否於相當水 準;國民之守法精神已否養成;國民之生活必需是否不虞匱乏;國民之氣質是否溫和 、服從理性;與乎以正義為基礎之社會平等是否存在;政黨活動是否正常等等,不一 而足。依 國父孫中山先生之遺教,民治之施行,猶需「以全縣人口,調查清楚。全 縣土地,測量完畢。全縣警衛,辦妥善。四境縱橫之道路,修築成功。而其人民曾受 四檯之訓練,而完畢其國民之義務,誓行革命之主義者,得選舉縣官,以執行一縣之 政事,得選舉議員,以議立一縣之法律,始成完全自治之縣」。 由於上列條件之未易俱備,且其每一條件又屬重要,台省如今是否已達水準可行普選 ﹖此一問題之答案,吾人雖已於書刊所述,報章所載,與日常生活體驗中,多所發現 ,然欲深求瞭解,猶有待於從民治基礎加以探討,故研究台省實施地方選舉之歷史背 景,思想淵源、社會環境、實不可缺。 誠然,縱使已具普選之條件,未必保証選舉之成功;蓋選舉之本身,猶備多種複雜難 行之條件也。而台省舉辦地方選舉,時值人心惶惶,國脈如縷之秋,益增問題之複雜 化,有待細心探索者多。 從辦理選務言,遠徵外史,歐美民主先進國家所示範於吾人者,即為選舉之公正與合 法欲求選公正,則平等之競選,公平之監察;公開之選務;與秘密之投票,似不可缺 。考選務之辦理與選舉之監察,在歐美民主先進國家,以美國為例,全國性與地方性 選舉,習慣上俱由民主、共和兩大政黨與地方政府共同負責;故選舉之結果如何,純 憑選民之決定,甚難發生公正與否之疑慮,輿論對此,自無懷疑。台省之政黨分野, 雖有國、民、青三黨之存在,但民、青兩黨在地方上之勢力如何,尚難知曉,是否定 以擔當共同監察選舉,辦理選務之能力,時論亦有所疑;尤有甚者,國人對黨派素乏 認識,所謂「群而不黨」,「吾聞君子不黨」,與「無偏無黨」之古訓,更予人以黨 派非善之觀念,故縱令採行美制,以國、民、青三黨參與辦理選務,共同監察選舉, 是否足以使無黨無派之競選者,信任選舉之公平,亦不無問題。如何抉擇,有待斟酌 。至秘密投票之施行,因憲法本無此一規定,原則上雖無問題,但執行時之如何確保 其貫徹,觀念上與技術上俱有困難。於公平之競選,主持選政者與選務人員是否能「 秉天下為公」之觀念,對待黨內同志與黨外人士一視同仁,似亦有待考驗;因法定雖 公,而執法在人也。另一方面,欲求選舉之合法,則需舉辦選舉之有據。憲法明定省 縣自治法之制定,須依中央制定之省縣自治通則,而該一通則,迄未頒布,則台省之 舉辦地方選舉,究何所據,亦為煞費思索之問題。
416

公務人員高等考試錄取者人口特性之比較分析

康文聰 Unknown Date (has links)
公務人員受委託行使行政權,享有身分保障和穩定收入,因而被視為社會體系的中上階層。基於此等特性,學者曾經提出代表性官僚理論與多元代表性等理論,希望能夠以此調和民主與效率兩大價值,達成政策執行的實質公平。然過去相關的實證研究,多半屬於「事後檢測」。但是我國公民除了通過公務人員考試之外,幾乎沒有其他擠身常任文官的管道,因此有關代表性或多元性的討論應該包括考試階段。換言之,考試錄取人員的人口特性值得深入的分析。本研究以2003至2007年的高等考試參與者為主要研究對象,輔以司法官三等考試的資料以利比較。接著,引用社會學「地位取得」的分析架構,採取指數比較分析與邏輯迴歸分析,探索性別、年齡、受教育時間、畢業學校特性、出身地域與錄取與否的關係。   本研究結果顯示,女性、非傳統公立綜合大學的畢業生、鄉鎮地區出身者以及41歲以上的考生在公務人員考試中處於較為不利的地位,但是與優勢團體之間的差距隨著考試等級和種類有所不同。例如女性在行政類與司法官考試中,與男性的表現平分秋色甚至猶有過之;剛完成高等教育的25歲以下人口在司法官考試裡最具優勢,但高考三級則有利於26至35歲的青年;傳統公立大學的文憑與都市出身的背景,在技術類考試能發揮的正效果比行政類考試為弱。基於上述的研究發現,為消除各種團體在公務人員考試裡的地位差距,本研究對於未來的考選政策提出下列建議:1.加強命題與口試委員的多元化;2.強化試題的研究發展;3.配合政府再造鬆綁人事法規;4.營造一個落實多元平等的大環境。 / Civil servants, with administrative power in hand, are commonly regarded as part of upper class. Therefore, researchers, to integrate democracy and efficiency in civil service system and to realize the genuine equality, propose representative bureaucracy and team diversity theory. Senior Civil Service Examination, the main approach, if not only, for citizens in Taiwan to enter the bureaucracy affects the representativeness and diversity of state apparatus substantially. By adopting the research approach of “status attainment” from sociology, this study gives an account of the relation between the examination result and the demographics in terms of gender, education, school characteristic, and region. All the data of this research is based on participators’ personnel information cards collected by the Ministry of Examination from 2003 to 2007. The result indicates that four types of participators are inferior in the examination, including women, graduates from private untraditional technological colleges, participators from rural areas, and adults above forty-one years old. The differences between superior and inferior groups, however, vary with the level and subject of examination. To prevent demographic differences in Senior Civil Service Examination, the study suggests the following factors be considered: the diversity of the composition of examiners committee should be ensured, the enhancement of development research of test questions, the deregulation of public personnel rules and, last but not least, the construction of a diversity-respecting society.
417

Processor design-space exploration through fast simulation / Exploration de l'espace de conception de processeurs via simulation accélérée

Khan, Taj Muhammad 12 May 2011 (has links)
Nous nous focalisons sur l'échantillonnage comme une technique de simulation pour réduire le temps de simulation. L'échantillonnage est basé sur le fait que l'exécution d'un programme est composée des parties du code qui se répètent, les phases. D'où vient l'observation que l'on peut éviter la simulation entière d'un programme et simuler chaque phase juste une fois et à partir de leurs performances calculer la performance du programme entier. Deux questions importantes se lèvent: quelles parties du programme doit-on simuler? Et comment restaurer l'état du système avant chaque simulation? Pour répondre à la première question, il existe deux solutions: une qui analyse l'exécution du programme en termes de phases et choisit de simuler chaque phase une fois, l'échantillonnage représentatif, et une deuxième qui prône de choisir les échantillons aléatoirement, l'échantillonnage statistique. Pour répondre à la deuxième question de la restauration de l'état du système, des techniques ont été développées récemment qui restaurent l'état (chauffent) du système en fonction des besoins du bout du code simulé (adaptativement). Les techniques des choix des échantillons ignorent complètement les mécanismes de chauffage du système ou proposent des alternatives qui demandent beaucoup de modification du simulateur et les techniques adaptatives du chauffage ne sont pas compatibles avec la plupart des techniques d'échantillonnage. Au sein de cette thèse nous nous focalisons sur le fait de réconcilier les techniques d'échantillonnage avec celles du chauffage adaptatif pour développer un mécanisme qui soit à la fois facile à utiliser, précis dans ses résultats, et soit transparent à l'utilisateur. Nous avons prit l'échantillonnage représentatif et statistique et modifié les techniques adaptatives du chauffage pour les rendre compatibles avec ces premiers dans un seul mécanisme. Nous avons pu montrer que les techniques adaptatives du chauffage peuvent être employées dans l'échantillonnage. Nos résultats sont comparables avec l'état de l'art en terme de précision mais en débarrassant l'utilisateur des problèmes du chauffage et en lui cachant les détails de la simulation, nous rendons le processus plus facile. On a aussi constaté que l'échantillonnage statistique donne des résultats meilleurs que l'échantillonnage représentatif / Simulation is a vital tool used by architects to develop new architectures. However, because of the complexity of modern architectures and the length of recent benchmarks, detailed simulation of programs can take extremely long times. This impedes the exploration of processor design space which the architects need to do to find the optimal configuration of processor parameters. Sampling is one technique which reduces the simulation time without adversely affecting the accuracy of the results. Yet, most sampling techniques either ignore the warm-up issue or require significant development effort on the part of the user.In this thesis we tackle the problem of reconciling state-of-the-art warm-up techniques and the latest sampling mechanisms with the triple objective of keeping the user effort minimum, achieving good accuracy and being agnostic to software and hardware changes. We show that both the representative and statistical sampling techniques can be adapted to use warm-up mechanisms which can accommodate the underlying architecture's warm-up requirements on-the-fly. We present the experimental results which show an accuracy and speed comparable to latest research. Also, we leverage statistical calculations to provide an estimate of the robustness of the final results.
418

Les défis de la politique européenne de défense

Ribet, Roseline 06 1900 (has links)
"Thèse présentée à la Faculté des études supérieures en vue de l'obtention du grade de Docteur en droit (LL.D) et à l'Université Jean Moulin en vue de l'obtention du grade de Docteur en droit" / Les États européens n'ont, jusque dans les années 90, envisagé leur défense que dans le cadre d'alliances militaires et restaient maîtres de leur défense nationale. La mise en place d'une politique européenne de défense a toujours connu des obstacles, reflets des problèmes de souveraineté. Dans l'Union européenne, l'intégration politique, et en particulier celle de la défense, reste le domaine le plus incertain. Cette thèse de nature essentiellement empirico-descriptive aborde le thème de la défense européenne sous une approche réaliste, en plaçant les États au centre de la construction européenne et en en faisant les acteurs principaux. Depuis 1992, les États tentent de définir une politique européenne de défense mais rencontrent différentes difficultés. En effet, la politique européenne de défense souffre d'un double déficit. Le premier est un déficit institutionnel puisque la P.E.D. est loin d'être une politique commune et se limite à un mécanisme de coopération. Le second est un déficit matériel puisque l'Union européenne n'a pas la puissance militaire pour mettre en oeuvre une éventuelle décision commune. Afin d'évaluer les perspectives d'évolution d'une politique européenne de défense, nous devons étudier les différents défis que les États et les institutions communautaires doivent relever pour combler ces deux déficits. Les défis d'ordre institutionnel concernent les multiples acteurs, États et institutions, qui interviennent dans la définition de la P.E.S.D. Il s'agit de déterminer quelle instance est la mieux à même d'assurer la représentation internationale de l'Union européenne afin de donner l'impulsion politique nécessaire de la P.E.S.D. Les défis d'ordre militaire concernent les moyens que les différents acteurs souhaitent engager afin de concrétiser la politique définie. Toutes ces discussions montrent la justification d'un système européen de défense mais la question est de savoir si les États, acteurs centraux de la construction européenne, sont prêts à relever ces défis. / Up until the 1990's, the European States have solely thought of their security forces inside military alliances as they kept control of their national defense. The putting in place of a European defense policy has always met obstacles, which reflect the problems linked to the preservation of sovereignty. The political integration in Europe remains uncertain, mostly when it comes to common defense. With an empirical and descriptive manner, this thesis depicts the European defense theme in a realistic approach, by placing the States in the middle of the European construction and by giving them the main role. Since 1992, the States tried to lay down a European policy of defense, but they encountered various difficulties. Indeed, the European policy of defense suffers from a double deficit. The first is institutional since the European Defense Policy is far from being part of a common policy and is strictly a cooperation mechanism. The second is a material deficit since the European Union doesn't have a military force to implement a common decision. In order to evaluate the possible evolution of a European defense policy, we had to study the various challenges that the States and institutions must face in order to address those two deficits. The institutional challenge concerns the multiple actors, States and institutions, which intervene in the definition of E.P.S.D. This part will try to identify which institution would be best capable of ensuring the international representation of the European Union and to give the political impetus necessary to the putting into place of the E.P.S.D. The military challenge concern the means that the different actors would engage in order to concretize the policy. Ali these discussions show the justification of a European system of defense, but the question remains as to whether the States, central figures of the European construction, are ready to take up these challenges.
419

A Comprehensive Analysis of the Legal Issues Relating to Nominee Directors

Sekouti, Sarah Samara 09 1900 (has links)
Dans la foulée des scandales financiers ayant secoué le milieu des affaires ces dernières années, l’efficacité des pratiques de régie d’entreprise, et, en particulier celles liées à l’indépendance des administrateurs, a été passée au crible. L’administrateur désigné par une partie pour la représenter est un type d’administrateur que l’on rencontre fréquemment au sein des conseils d’administration des entreprises. Toutefois, l’on peut se questionner sur l’indépendance réelle de ces administrateurs, considérant leur loyauté envers la personne les ayant désignés, laquelle détient habituellement un intérêt à titre d’actionnaire ou de partie prenante dans l’entreprise visée. En outre, alors que les principes légaux requièrent que les administrateurs agissent dans le meilleur intérêt de l’entreprise, la réalité pratique est parfois toute autre: aux prises avec les instructions ou les souhaits de la personne les ayant nommés, les administrateurs désignés se retrouvent placés en situation inhérente de conflit d’intérêts. Ce texte vise à offrir une analyse détaillée au sujet de l’administrateur désigné et du conflit d’intérêts résultant de cette double exigence de loyauté. L’objectif est de présenter un examen approfondi des diverses difficultés résultant de la nomination d’un administrateur désigné ou associées à celle-ci, ainsi que des réponses judiciaires et législatives liées à cette problématique. Cette réflexion mènera à une exploration de certains systèmes législatifs et légaux, en particulier ceux du Royaume-Uni, de l’Australie et de la Nouvelle-Zélande, afin d’obtenir une meilleure compréhension et d’offrir une perspective éclairée quant aux enjeux analysés par la présente. / Following the wave of corporate scandals that have surfaced over the past decade, significant attention has been showered on the efficiency of corporate governance practices, with particular scrutiny on the issue of director independence. One specific category of directors frequently nominated to sit on corporate boards is the nominee director. However, these directors often lack veritable independence given their extraneous loyalty towards their appointer, usually either a shareholder or stakeholder of the corporation. Furthermore, while legal principle requires that all company directors exercise their statutory duties with a view to the best interests of the corporation, in practice nominee directors are expected to follow the instructions or wishes of their appointer, resulting in their inherent position of conflict. This text focuses on the nominee director and the conflict of interest resulting from such director’s position of dual loyalty. Its objective is to provide a comprehensive examination of the various difficulties arising from, and associated with the appointment of nominee directors as well as the judicial and legislative responses to these difficulties. In examining the various complications associated with nominee directors, the legal framework in several foreign jurisdictions, particularly the United Kingdom, Australia and New Zealand is also explored throughout this text to provide further insight and perspective on the different issues analysed herein.
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Homogénéisation des composites linéaires : Etude des comportements apparents et effectif / Homogenization of linear elastic matrix-inclusion composites : a study of their apparent and effective behaviors

Salmi, Moncef 02 July 2012 (has links)
Les travaux effectués au cours de cette thèse portent principalement sur la construction de nouvelles bornes du comportement effectif des matériaux biphasés de type matrice-inclusions à comportement linéaire élastique. Dans un premier temps, afin d’encadrer le comportement effectif, nous présentons une nouvelle approche numérique, inspirée des travaux de Huet (J. Mech. Phys. Solids 1990 ; 38:813-41), qui repose sur le calcul des comportements apparents associés à des volumes élémentaires (VE) non-carrés construits à partir d'assemblages de cellules de Voronoï, chaque cellule contenant une inclusion entourée de matrice. De tels VE non-carrés permettent d'éviter l'application directe des CL sur les inclusions à l’origine d’une surestimation artificielle des comportements apparents. En utilisant les théorèmes énergétiques de l'élasticité linéaire et des procédures de moyennisation appropriées portant sur les comportements apparents, un nouvel encadrement du comportement effectif est obtenu. Son application au cas d'un composite biphasé, constitué d'une matrice isotrope et de fibres cylindriques parallèles et identiques distribuées aléatoirement dans le plan transverse, conduit à des bornes plus resserrées que celles obtenues par Huet. En nous appuyant sur cette nouvelle procédure numérique, nous avons ensuite réalisé une étude statistique des comportements apparents à l'aide de simulations de type Monté Carlo. Puis, à partir des tendances issues de cette étude statistique, nous avons proposé et mis en œuvre de nouveaux critères de tailles de VER. / This work is devoted to the derivation of improved bounds for the effective behavior of random linear elastic matrix-inclusions composites. In order to bounds their effective behavior, we present a new numerical approach, inspired by the works of Huet (J. Mech. Phys. Solids 1990 ; 38:813-41), which relies on the computation of the apparent behaviors associated to non square (or non cubic) volume elements (VEs) comprised of Voronoï cells assemblages, each cell being composed of a single inclusion surrounded by the matrix. Such non-square VEs forbid any direct application of boundary conditions to particles which is responsible for the artificial overestimation of the apparent behaviors observed for square VEs. By making used of the classical bounding theorems for linear elasticity and appropriate averaging procedures, new bounds are derived from ensemble averages of the apparent behavior associated with non square VEs. Their application to a two-phase composite composed of an isotropic matrix and aligned identical fibers randomly and isotropically distributed in the transverse plane leads to sharper bounds than those obtained by Huet. Then, by making use of this new numerical approach, a statistical study of the apparent behavior is carried out by means of Monte Carlo simulations. Subsequently, relying on the trends derived from this study, some proposals to define RVE criteria are presented.

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