Portable languages and distributed paradigms have driven a wave of new applications and processing models. One of the most promising, certainly from its early marketing, but disappointing (from its limited uptake)is the mobile agent execution and data processing model. Mobile agents are autonomous programs which can move around a heterogeneous network such as the Internet, crossing through a number of different security domains, and perform some work at each visited destination as partial completion of a mission for their agent user. Despite their promise as a technology and paradigm to drive global electronic services (i.e.any Internet-driven-and-delivered service, not solely e-commerce related activities), their up take on the Internet has been very limited. Chief among the reasons for the paradigm's practical under-achievement is there is no ubiquitous frame work for using Internet mobile agents, and non-trivial security concerns abound for the two major stake holders (mobile agent users and mobile agent platform owners). While both stake holders have security concerns with the dangers of the mobile agent processing model, most investigators in the field are of the opinion that protecting mobile agents from malicious agent platforms is more problematic than protecting agent platforms from malicious mobile agents. Traditional cryptographic mechanisms are not well-suited to counter the bulk of the threats associated with the mobile agent paradigm due to the untrusted hosting of an agent and its intended autonomous, flexible movement and processing. In our investigation, we identified that the large majority of the research undertaken on mobile agent security to date has taken a micro-level perspective. By this we mean research focused solely on either of the two major stakeholders, and even then often only on improving measures to address one security issue dear to the stake holder - for example mobile agent privacy (for agent users) or access control to platform resources (for mobile agent platform owners). We decided to take a more encompassing, higher-level approach in tackling mobile agent security issues. In this endeavour, we developed the beginnings of an infrastructural-approach to not only reduce the security concerns of both major stakeholders, but bring them transparently to a working relationship. Strategic utilisation of both existing distributed system trusted-third parties (TTPs) and novel mobile agent paradigm-specific TTPs are fundamental in the infrastructural framework we have devised. Besides designing an application and language independent frame work for supporting a large-scale Internet mobile agent network, our Mobile Agent Secure Hub Infrastructure (MASHIn) proposal encompasses support for flexible access control to agent platform resources. A reliable means to track the location and processing times of autonomous Internet mobile agents is discussed, withfault-tolerant handling support to work around unexpected processing delays. Secure,highly-effective (incomparison to existing mechanisms) strategies for providing mobile agent privacy, execution integrity, and stake holder confidence scores were devised - all which fit comfortably within the MASHIn framework. We have deliberately considered the interests - withoutbias -of both stake holders when designing our solutions. In relation to mobile agent execution integrity, we devised a new criteria for assessing the robustness of existing execution integrity schemes. Whilst none of the existing schemes analysed met a large number of our desired properties for a robust scheme, we identified that the objectives of Hohl's reference states scheme were most admirable - particularly real - time in - mission execution integrity checking. Subsequently, we revised Hohl's reference states protocols to fit in the MASHIn framework, and were able to overcome not only the two major limitations identified in his scheme, but also meet all of our desired properties for a robust execution integrity scheme (given an acceptable decrease in processing effiency). The MASHIn offers a promising new perspective for future mobile agent security research and indeed a new frame work for enabling safe and autonomous Internet mobile agents. Just as an economy cannot thrive without diligent care given to micro and macro-level issues, we do not see the security prospects of mobile agents (and ultimately the prospects of the mobile agent paradigm) advancing without diligent research on both levels.

Universally complications exist concerning insurance cover for the risks posed by pollution damage. Environmental insurance cover can be procured under first-party or third-party insurance. For the latter, the polluter's statutory or civil liability is required. The determination of liability for compensation, especially delictual liability, remains problematic. The right to the environment in section 24 of the Constitution creates a general duty of care. The introduction of a strict liability regime can be recommended to alleviate the burden of proving fault and contributory negligence. Where there is multiple or cumulative causation or the exact identity of the polluter is unknown, potential solutions regarding the allocation of liability include a pollution-share, joint and several, market-share or, as a last resort, a proportional allocation. Actionable damages should include property damage, pure economic loss, clean-up costs and natural resource damages, including compensation for reduced aesthetic value. Due to the uncertainty and potential magnitude of pollution-related claims, insurers have attempted to avoid or limit these risks by including specific pollution exclusion and limitation clauses in policies. Statutory regulation of policy content and prescribed wording for clauses could address problems relating to the interpretation of policy provisions. Various other issues such as the coverage of gradual pollution, the effect of the various triggers of coverage and the potential long-tail liability of insurer, the lack of information and the unpredictability of the risk cause further complications for both the insured and the insurer. Policies should preferably be issued on a `claims-made' basis linked to retroactive dates. Mandatory third-party insurance to the benefit of a third party should be required within specific high-risk industries, specifically for the benefit of the prejudiced person or an environmental remediation fund. The right of a prejudiced party to claim directly from the polluter's liability insurer should be introduced. Currently, the focus appears to be more on protection and environmental remediation than on civil compensation. There is an urgent need for the development of statutory and civil liability compensation mechanisms and for an increased regulation of insurance policies and practices to ensure effective insurance cover to provide compensation for environmental damage. / Jurisprudence / LL.D.

Abstracts in English, Afrikaans and Southern Sotho / The prevalence of hate victimisation in South Africa remains unknown, as does its full impact. Anecdotal evidence, borne out by recent research findings, suggests hate-based attacks on non-nationals have increased in recent years, distinctly reflecting a picture of heightened vulnerability. For several reasons, the severity of such victimisation, and their physical and psychological impact, go mostly unseen. Hate-motivated incidents, such as hate speech and intentional unfair discrimination, are possible precursors to additional criminal victimisation. Records of such incidents can be helpful to demonstrate both a context of harassment and evidence of escalating patterns of violence. Worldwide, under-reporting of hate victimisation is a longstanding concern and requires an urgent solution. In South Africa, under-reporting has contributed to the nonrecognition of hate crime as a separate crime category. Towards aiding in finding a solution, this study explored the psychological barriers to reporting xenophobic victimisation to relevant authorities. The study, furthermore, explored with a group of victims who experienced xenophobia whether they reported victimisation, the reasons for reporting and under-reporting, and their thoughts and opinions on the workability of a third-party reporting mechanism. Non-probability sampling, specifically applying convenience and purposive sampling was used to obtain 19 participants for the four semi-structured focus groups. While all participants reported being victimised because of their nationality, the study found that multiple psychological barriers prevent such victims of xenophobia from reporting victimisation to authorities. Many of the participants do not believe in the workability of third-party reporting mechanisms. / Dit is onbekend hoe algemeen viktimisering op grond van haat in Suid-Afrika voorkom, en daarom ook wat die volle impak daarvan is. Onlangse navorsingsresultate dui egter daarop dat aanvalle op nielandsburgers wat uit haat voortspruit, toegeneem het die afgelope paar jaar, wat hulle groter kwesbaarheid duidelik weerspieël. Die intensiteit van hierdie viktimisering, asook die fisieke en sielkundige impak daarvan word in die meeste gevalle om verskeie redes ook nie bekendgemaak nie. Voorvalle wat uit haat voortspruit, soos haatspraak en doelbewuste onregverdige diskriminasie, is moontlik voorlopers van verdere kriminele viktimisering. Die optekening van sulke gevalle kan help om bewys te lewer van die teisteringskonteks, sowel as van patrone van toenemende misdaad. Die gebrekkige aanmelding van viktimisering op grond van haat is wêreldwyd lank reeds ’n probleem, en een waarvoor daar dringend ’n oplossing gevind moet word. In Suid-Afrika het gebrekkige aanmelding daartoe bygedra dat haatmisdaad nie as ’n aparte misdaadkategorie erken word nie. Ten einde ’n oplossing te help vind, het die navorser vir die doeleindes van hierdie studie die sielkundige faktore ondersoek wat verhoed dat xenofobiese viktimisering by die betrokke owerhede aangemeld word. Die studie bevat ook die terugvoer van ’n groep slagoffers van xenofobie oor hulle aanmelding van die viktimisering al dan nie, die redes waarom hulle dit aangemeld het of nie aangemeld het nie, en hulle gedagtes en menings oor hoe lewensvatbaar ’n stelsel vir derdeparty-aanmelding is. Niewaarskynlikheid-steekproefneming, en spesifiek doelbewuste en gemaksteekproefneming is gebruik om 19 deelnemers vir die vier semigestruktureerde fokusgroepe te vind. Alhoewel al die deelnemers bevestig het dat hulle geviktimiseer is op grond van hulle nasionaliteit, het die navorser met hierdie studie bevind dat verskeie sielkundige faktore die slagoffers van xenofobie verhoed om die viktimisering by die owerhede aan te meld. Talle van die deelnemers glo nie dat stelsels vir derdeparty-aanmelding ’n werkbare oplossing is nie. / Hore na tshwaro e mpe ka lebaka la lehloyo e atile hakae Afrika Borwa ho ntse ho sa tsejwe, le ditlamorao tsa yona ha di tsejwe. Bopaki bo sa netefatswang, bo hlaheletseng dipatlisisong tsa morao tjena, bo bontsha hore ditlhaselo tse etswang ho batho ba tswang dinaheng tse ding di eketsehile morao tjena, e leng se bontshang hore ba kotsing le ho feta. Ho na le mabaka a mmalwa a etsang hore ho pharalla ha tshwaro e mpe jwalo, ho hlokofatswa mmeleng le maikutlong ho se ke ha bonahala. Diketso tse hlohleletswang ke lehloyo, tse kang dipuo tse nang le lehloyo le kgethollo e etswang ka boomo, e ba selelekela sa diketso tsa bonokwane tsa tshwaro e mpe. Ho tlalehwa ho diketso tseo ho ka thusa ho bontsha maemo a lebisang tshwarong e mpe mme ha fana ka bopaki ba hore diketso tse mabifi di ntse di eketseha. Lefatsheng ka bophara, taba ya ho se tlalehwe ha tshwaro e mpe e hlohleletswang ke lehloyo haesale e le qaka mme ho hlokahala tharollo ka potlako. Afrika Borwa, ho se tlalehwe hona ho entse hore diketso tsa bonokwane tse hlohleletswang ke lehloyo di se ke tsa nkwa e le diketso tse ikemetseng tsa bonokwane. Ho thusa ho fumana tharollo, phuputso ena e lekola mathata a maikutlo a sitisang matswantle ho tlaleha tshwaro e mpe ho ba boholong ba ikarabellang. Ho feta moo, phuputso ena e lekola matswantle ao e leng mahlatsipa a tshwaro e mpe hore na a ile a e tlaleha, mabaka a entseng hore a e tlalehe, a se ke a tlaleha le hore na a nahanang ka ho sebediswa ha mokena-dipakeng. Ho kgethilwe bankakarolo ba 19 ka hloko e le sampole, ba kgethwa ka sepheo le morero o tobileng hore ba be dihlopheng tse nne tse sa hlophiswang ka ho feletseng. Le hoja bankakarolo bohle ba tlalehile hore ba tshwerwe hampe ka lebaka la botjhaba ba bona, phuputso e fumana hore ho na le mathata a mmalwa a maikutlo a thibelang mahlatsipa a tshwaro e mpe ya matswantle ho tlalehela ba boholong. Bankakarolo ba bangata ha ba dumele hore ho tlalehela mokena-dipakeng ho tla thusa. / Psychology / M.A. (Psychology)

La logistique urbaine, et celle du dernier kilomètre notamment, est un sujet de préoccupation majeure pour les villes d’aujourd’hui. Pour répondre à cette préoccupation, nous avons établi dans le chapitre introductif un historique de la problématique de la logistique urbaine pour mieux comprendre son développement au fil des années, permettant ainsi de déduire qu’il est fondamental d’étudier la globalité de la chaîne de distribution dans ce travail de thèse pour mieux résoudre la problématique de la logistique urbaine. En revanche, nous étions confrontés à un sujet redoutable par sa complexité et l’absence de données complètes et fiables. De plus, nous assistons dans les dernières années, à une multiplication des schémas logistiques que ce soit pour la livraison des magasins à partir des entrepôts des fournisseurs ou pour l’approvisionnement des clients à partir des surfaces de vente.De ce fait, nous avons fixé comme objectif d’identifier toutes les organisations logistiques existantes et émergentes en France et ailleurs (deux séjours d’un an en Angleterre et en Suisse). Pour ce faire, nous avons déterminé dans le deuxième chapitre les paramètres de différenciation des modes d’organisation en amont (de l’entrepôt du fournisseur à la surface de vente) et en aval de la chaîne (de la surface de vente au domicile du client). Or il n’existe pas aujourd’hui de bilan économique et environnemental complet permettant d’arbitrer entre différentes formes de distribution classiques et à distance en tenant compte des particularités des familles des produits (non alimentaires, secs, frais, surgelés) et de la diversité de leurs modes de livraison.Face à ces contraintes de taille, nous avons eu recours aux enquêtes de terrain dans ce travail de recherche, qui ont été l’occasion de nouer de très nombreux contacts avec les acteurs de la grande distribution, permettant ainsi de recueillir des données techniques et économiques de première main et inédites jusqu’ici. En plus de la résolution du verrou empirique dans le troisième chapitre, ce travail de thèse a permis également de lever des verrous méthodologiques relatifs à la reconstitution et à l’évaluation des coûts et des émissions logistiques (pour les entrepôts de stockage et les plateformes de transit en amont ; et pour les surfaces de vente et les plateforme de mutualisation en aval) et des coûts et des émissions des véhicules de transport (des articulés et des porteurs en amont ; et des VUL, voitures particulières, transports publics, deux roues, et marche à pied en aval). Enfin, ce travail de thèse a permis d’aboutir à la construction d’une base de données et la mise au point d’un outil d’aide à la décision permettant ainsi de déduire, dans le quatrième chapitre, les bilans économique et environnemental de la globalité de la chaîne depuis l’entrepôt du fournisseur jusqu’au domicile du ménage. Cet outil devrait se révéler très utile pour les politiques publiques, les stratégies futures des grands distributeurs et leurs prestataires logistiques afin de privilégier les modes d’organisation économes et durables, et même pour le client final afin d’estimer les coûts et les émissions de ses actes d’achat dans les différentes alternatives de vente classique et à distance. / Urban logistics and the last mile in particular, is a major concern for cities today. To address this concern, we have established in the introductory chapter a history of the problem of urban logistics. This allows a better understanding of its development over the years, and deducing that it’s essential to study the supply chain in its entirety to better solve the problem of urban logistics. However, we were faced with a daunting task: the lack of comprehensive and reliable data. In addition, there has been a multiplication of distribution channels in recent years. This includes the delivery from warehouses to stores and further to households from the retail space.Therefore, we intended to identify all existing and emerging logistics organizations in France and beyond (one year exchange stay in England and Switzerland for research purposes). To do this, we established in the second chapter certain parameters that differentiate the logistics modes of various organizations upstream (from manufacturers to retail stores) and downstream (from retail stores to households). Unfortunately, there does not exist any economic and environmental assessment to settle between different forms of traditional and modern electronic distribution, by taking into account the various characteristics of different products families (non-food, dry, fresh, frozen) and the diversity of their delivery modes.Faced with constraints of such size, we conducted surveys with different actors of distribution channels, which provided the opportunity to make contacts, thus collect firsthand and so far unpublished technical and economic data. In addition to the resolution of empirical inadequacy in the third chapter, this research also helped to develop a methodological approach related to the reconstruction and evaluation of logistics costs and emissions (in warehouses, transit platforms, retail stores and shared platforms) and also the costs and emissions of vehicles (trucks, delivery van, cars, public transport, bikes, motorbikes and walking).Finally, this research has lead to the construction of a database and the development of a decision support tool to infer, in the fourth chapter, the economic and environmental appraisal of the entire supply chain from the supplier's warehouse to the final customer. This tool can be useful for public policy, future strategies of retailers and Third-Party Logistics providers to focus on efficient and sustainable modes of organization, and even it will benefit the customer to estimate the costs and emissions of its acts of purchase in classic and e-grocery shopping.