Academic literature on the topic 'Establishment'

Thesis (MAcc)--Stellenbosch University, 2010.<br>ENGLISH ABSTRACT: The Income Tax Act, Act 58 of 1962 (‘the Act’) currently defines a permanent establishment in section 1. The definition of a permanent establishment in the Act refers to article 5 of the Model Tax Convention on Income and on Capital of the Organisation for Economic Co- Operation and Development. The existence of a permanent establishment in a tax jurisdiction determines the right of the jurisdiction to tax the profits of the permanent establishment. The concept foreign business establishment was inserted into section 9D of the Act by clause 10(1)(a) of the Revenue Laws Amendment Act, Act 59 of 2000. Section 9D is an antiavoidance provision, which determines that certain foreign-sourced income generated by South African controlled foreign companies are subject to tax in South Africa. The concept foreign business establishment is one of the exclusions from the anti-avoidance provisions in section 9D. The Revenue Laws Amendment Act, Act 59 of 2000, replaced all references to the concept permanent establishment with a reference to the newly introduced concept foreign business establishment in section 9D(9)(b) of the Act. The Explanatory Memorandum on the Revenue Laws Amendment Bill, 2000 (SARS 2000:1-12) does not provide a reason for the replacement of the concept permanent establishment. The objective of this study was to analyse and compare the concepts permanent establishment and foreign business establishment in order to make recommendations regarding the required additions and amendments to replace the concept foreign business establishment with the internationally recognised and accepted concept permanent establishment. The proposed replacement of the concept foreign business establishment with an internationally recognised and accepted tax concept will enhance the international compatibility of the Act. The use of an internationally recognised and accepted tax concept will provide clarity and certainty regarding the tax implications of section 9D(9)(b) for those affected by it. It was found that the concepts permanent establishment and foreign business establishment are used in different contexts within the Act. The concepts also apply to different types of taxpayers in different situations. The two concepts have, however, the same objective, being the identification of criteria for the existence of legitimate and substantive business activities in the foreign tax jurisdiction. A comparison between the definitions of the two concepts reveals that there are various components in the definitions with the same wording and meaning. After a detailed comparison between the two definitions it was found that, subject to some suggested additions and amendments, the internationally recognised and accepted concept permanent establishment can replace the concept foreign business establishment in section 9D(9)(b) of the Act without having a material impact on the objective of section 9D(9)(b). This replacement is possible due to the mutual objective of and similar components contained in the definitions of the concepts permanent establishment and foreign business establishments.<br>AFRIKAANSE OPSOMMING: Die Inkomstebelastingwet, Wet 58 van 1962 (‘die Wet’) definieer ’n permanente saak in artikel 1. Die definisie van ’n permanente saak verwys na artikel 5 van die ‘Model Tax Convention on Income and on Capital of the Organisation for Economic Co-Operation and Development’. Die bestaan van ’n permanente saak in ’n belastingjurisdiksie bepaal die reg van die belastingjurisdiksie om die winste van die permanente saak te belas. Die begrip buitelandse besigheidsaak is deur artikel 10(1)(a) van die Wysigingswet op Inkomstewette, Wet 59 van 2000 in die Wet ingesluit. Artikel 9D is ’n teenvermydingsbepaling wat bepaal dat sekere inkomste vanaf ’n buitelandse bron gegenereer deur ’n Suid-Afrikaans beheerde buitelandse maatskappy in Suid-Afrika belas word. Die begrip buitelandse besigheidsaak is een van die uitsluitings van die teenvermydingsbepaling in artikel 9D. Alle verwysings in artikel 9D(9)(b) na die begrip permanente saak is deur die Wysigingswet op Inkomstewette, Wet 59 van 2000, vervang met ’n verwysing na die nuwe begrip buitelandse besigheidsaak. Die ‘Explanatory Memorandum on the Revenue Laws Amendment Bill, 2000’ (SARS 2000:1-12) verskaf nie ’n rede vir die vervanging van die begrip permanente saak nie. Die doel van die studie was om die begrippe permanente saak en buitelandse besigheidsaak te vergelyk sodat voorstelle gemaak kan word rakende die nodige byvoegings en wysings om die begrip buitelandse besigheidsaak met die internasionaal aanvaarde en erkende begrip, permanente saak, te vervang. Die voorgestelde vervanging van die begrip buitelandse besigheidsaak met ’n internasionaal aanvaarde en erkende begrip sal die internasionale verenigbaarheid van die Suid Afrikaanse wetgewing bevorder. Die gebruik van ’n begrip wat internasionaal aanvaar en erken word, sal sekerheid en duidelikheid bewerkstellig vir diegene wat deur die artikel geaffekteer word. Daar is bevind dat die begrippe permanente saak en buitelandse besigheidsaak in die Wet in verskillende verbande gebruik word. Die begrippe is ook van toepassing op verskillende belastingbetalers in verskillende situasies. Die twee begrippe het egter dieselfde doelwit naamlik die identifisering van kriteria vir die bestaan van wesenlike en volwaardige besigheidsaktiwiteite in die buitelandse belastingjurisdiksie. ’n Vergelyking tussen die definisies van die twee begrippe toon dat verskeie komponente van die definisies dieselfde woorde en betekenis bevat. Na ’n detail vergelyking van die twee begrippe is daar bevind dat, onderhewig aan sommige voorgestelde byvoegings en wysigings, die internasionaal erkende en aanvaarde begrip permanente saak die begrip buitelandse besigheidsaak in artikel 9D(9)(b) van die Wet kan vervang. Die vervanging is moontlik weens die gemeenskaplike doelwit en soortgelyke komponente in die definisies van die begrippe permanente saak en buitelandse besigheidsaak.

Information from actual farm fields can help corn producers understand the value and importance of establishing uniform plant emergence and within row plant spacing. Thirty-eight fields planted with corn (Zea mays L.) by North Dakota producers were evaluated to determine effects of uneven plant emergence timing and within-row plant space variability, as well as identifying contributing factors. Rows within a planter?s width with the most variability yielded 6% less than the least variable. Individual ear weights decreased as the number of days after normal emergence (date when 50% of plant stand emerged) increased. Ears next to within-row gaps weighed 11% more than the normally spaced plants. Combined ears from both plants situated <5.1 cm apart weighed 36% more than the normal emerged. Residue impacted stand establishment variability more than other factors measured. Producers should assess each field environment individually in order to identify best practices to achieve uniform stand establishment.<br>North Dakota Corn Utilization Council

Doutoramento em Engenharia Informática<br>Uma das áreas de investigação em Telecomunicações de interesse crescente prende-se com os futuros sistemas de comunicações móveis de 4a geração e além destes. Nos últimos anos tem sido desenvolvido o conceito de redes comunitárias, no qual os utilizadores se agregam de acordo com interesses comuns. Estes conceitos têm sido explorados de uma forma horizontal em diferentes camadas da comunicação, desde as redes comunitárias de comunicação (Seattle Wireless ou Personal Telco, p.ex.) até às redes de interesses peer-to-peer. No entanto, estas redes são usualmente vistas como redes de overlay, ou simplesmente redes de associação livre. Na prática, a noção de uma rede auto-organizada, completamente orientada ao serviço/comunidade, integralmente suportada em termos de arquitetura, não existe. Assim este trabalho apresenta uma realização original nesta área de criação de redes comunitárias, com uma arquitetura subjacente orientada a serviço, e que suporta integralmente múltiplas redes comunitárias no mesmo dispositivo, com todas as características de segurança, confiança e disponibilização de serviço necessárias neste tipo de cenários (um nó pode pertencer simultaneamente a mais do que uma rede comunitária). Devido à sua importância para os sistemas de redes comunitárias, foi dado particular atenção a aspetos de gestão de recursos e controlo de acessos. Ambos realizados de uma forma descentralizada e considerando mecanismos dotados de grande escalabilidade. Para isso, é apresentada uma linguagem de políticas que suporta a criação de comunidades virtuais. Esta linguagem não é apenas utilizada para o mapeamento da estrutura social dos membros da comunidade, como para, gerir dispositivos, recursos e serviços detidos pelos membros, de uma forma controlada e distribuída.<br>One of the research areas with increasing interest in the field of telecommunications, are the ones related to future telecommunication systems, both 4th generation and beyond. In parallel, during the last years, several concepts have been developed related to clustering of users according to their interested, in the form of community networks. Solutions proposed for these concepts tackle the challenges horizontally, for each layer of the communication stack, ranging from community based communication networks (e.g. Seattle Wireless, or Personal Telco), to interest networks based on peer-to-peer protocols. However, these networks are presented either as free joining, or overlay networks. In practice, the notion of a self-organized, service and community oriented network, with these principles embedded in its design principles, is yet to be developed. This work presents an novel instantiation of a solution in the area of community networks, with a underlying architecture which is fully service oriented, and envisions the support for multiple community networks in the same device. Considerations regarding security, trust and service availability for this type of environments are also taken. Due to the importance of resource management and access control, in the context of community driven communication networks, a special focus was given to the support of scalable and decentralized management and access control methods. For this purpose, it is presented a policy language which supports the creation and management of virtual communities. The language is not only used for mapping the social structure of the community members, but also to, following a distributed approach, manage devices, resources and services owned by each community member.

Poster paper. In Chinese.<br>The paper introduces a general digital resource management system. It elaborates on the core design and components of the system. The general digital resource management system was developed based on the Fedora system, and incorporates the concept of virtual collections. The system is composed of seven models: rights management, collection management, resource access, resource tagging, interoperability, and customization.

We study the problem of secure key establishment. We critically examine the security models of Bellare and Rogaway (1993) and Canetti and Krawczyk (2001) in the computational complexity approach, as these models are central in the understanding of the provable security paradigm. We show that the partnership definition used in the three-party key distribution (3PKD) protocol of Bellare and Rogaway (1995) is flawed, which invalidates the proof for the 3PKD protocol. We present an improved protocol with a new proof of security. We identify several variants of the key sharing requirement (i.e., two entities who have completed matching sessions, partners, are required to accept the same session key). We then present a brief discussion about the key sharing requirement. We identify several variants of the Bellare and Rogaway (1993) model. We present a comparative study of the relative strengths of security notions between the several variants of the Bellare-Rogaway model and the Canetti-Krawczyk model. In our comparative study, we reveal a drawback in the Bellare, Pointcheval, and Rogaway (2000) model with the protocol of Abdalla and Pointcheval (2005) as a case study. We prove a revised protocol of Boyd (1996) secure in the Bellare-Rogaway model. We then extend the model in order to allow more realistic adversary capabilities by incorporating the notion of resetting the long-term compromised key of some entity. This allows us to detect a known weakness of the protocol that cannot be captured in the original model. We also present an alternative protocol that is efficient in both messages and rounds. We prove the protocol secure in the extended model. We point out previously unknown flaws in several published protocols and a message authenticator of Bellare, Canetti, and Krawczyk (1998) by refuting claimed proofs of security. We also point out corresponding flaws in their existing proofs. We propose fixes to these protocols and their proofs. In some cases, we present new protocols with full proofs of security. We examine the role of session key construction in key establishment protocols, and demonstrate that a small change to the way that session keys are constructed can have significant benefits. Protocols that were proven secure in a restricted Bellare-Rogaway model can then be proven secure in the full model. We present a brief discussion on ways to construct session keys in key establishment protocols and also prove the protocol of Chen and Kudla (2003) secure in a less restrictive Bellare-Rogaway model. To complement the computational complexity approach, we provide a formal specification and machine analysis of the Bellare-Pointcheval-Rogaway model using an automated model checker, Simple Homomorphism Verification Tool (SHVT). We demonstrate that structural flaws in protocols can be revealed using our framework. We reveal previously unknown flaws in the unpublished preproceedings version of the protocol due to Jakobsson and Pointcheval (2001) and several published protocols with only heuristic security arguments. We conclude this thesis with a listing of some open problems that were encountered in the study.

We study the problem of secure key establishment. We critically examine the security models of Bellare and Rogaway (1993) and Canetti and Krawczyk (2001) in the computational complexity approach, as these models are central in the understanding of the provable security paradigm. We show that the partnership definition used in the three-party key distribution (3PKD) protocol of Bellare and Rogaway (1995) is flawed, which invalidates the proof for the 3PKD protocol. We present an improved protocol with a new proof of security. We identify several variants of the key sharing requirement (i.e., two entities who have completed matching sessions, partners, are required to accept the same session key). We then present a brief discussion about the key sharing requirement. We identify several variants of the Bellare and Rogaway (1993) model. We present a comparative study of the relative strengths of security notions between the several variants of the Bellare-Rogaway model and the Canetti-Krawczyk model. In our comparative study, we reveal a drawback in the Bellare, Pointcheval, and Rogaway (2000) model with the protocol of Abdalla and Pointcheval (2005) as a case study. We prove a revised protocol of Boyd (1996) secure in the Bellare-Rogaway model. We then extend the model in order to allow more realistic adversary capabilities by incorporating the notion of resetting the long-term compromised key of some entity. This allows us to detect a known weakness of the protocol that cannot be captured in the original model. We also present an alternative protocol that is efficient in both messages and rounds. We prove the protocol secure in the extended model. We point out previously unknown flaws in several published protocols and a message authenticator of Bellare, Canetti, and Krawczyk (1998) by refuting claimed proofs of security. We also point out corresponding flaws in their existing proofs. We propose fixes to these protocols and their proofs. In some cases, we present new protocols with full proofs of security. We examine the role of session key construction in key establishment protocols, and demonstrate that a small change to the way that session keys are constructed can have significant benefits. Protocols that were proven secure in a restricted Bellare-Rogaway model can then be proven secure in the full model. We present a brief discussion on ways to construct session keys in key establishment protocols and also prove the protocol of Chen and Kudla (2003) secure in a less restrictive Bellare-Rogaway model. To complement the computational complexity approach, we provide a formal specification and machine analysis of the Bellare-Pointcheval-Rogaway model using an automated model checker, Simple Homomorphism Verification Tool (SHVT). We demonstrate that structural flaws in protocols can be revealed using our framework. We reveal previously unknown flaws in the unpublished preproceedings version of the protocol due to Jakobsson and Pointcheval (2001) and several published protocols with only heuristic security arguments. We conclude this thesis with a listing of some open problems that were encountered in the study.

Poor or failed crop establishment is a serious problem for farmers in the semi-arid tropics. Suboptimal stand densities or the necessity to re-sow can be a major factor in limiting crop yields. Establishment can be considered as the result of a set of complex interactions between the seed, the soil and the climate. The experiments detailed within this volume were carried out to determine parameters for sorghum germination for a model to predict crop emergence in the semi-arid tropics to aid the greater understanding of the causes of establishment problems. The cumulative germination of sorghum cv. Tegemeo was recorded in conditions of both constant temperatures and fluctuating temperatures on a thermogradient plate and at negative water potentials over a range of temperatures in solutions of polyethylene glycol and in soil. Results demonstrate that within a temperature range of 14 - 40oC germination can be predicted using a thermal time model. The effect of temperature fluctuation on the time to germination within this temperature range can be predicted using the same thermal time constants that model behaviour at constant temperatures. Prediction of the time to germination in soil using a hydrothermal model (Gummerson 1986) was found to be accurate over a wide range of temperatures (15 - 35oC) and soil matrix potentials (0 - -0.6 MPa). The results of this study have been incorporated into "EMERGE" (Mullins et al., 1996), a published crop emergence model. The potential use of hydrothermal modelling as a tool to investigate aspects of seed vigour is discussed.