Multiparameter QoS admission control for ATM queues with Partial Buffer Sharing Mechanism

In this paper, we present an admission control technique for mixed real-time and nonreal -time traffic in finite length queues with PBS cell loss control. Real-time connections have both delay and loss constraints while non-real-time connections are only subject to cell loss constraints. We propose to provide each type of traffic with a separate capacity subregion with different QoS bounds. We introduce the concept of virtual effective bandwidth (VEB) for the traffic source inside the capacity subregion. VEB of the source depends on the traffic descriptors of the source, QoS bound for a given traffic class, and on the sum of average arrival rates of connections from other traffic classes. In the case of one capacity region, virtual effective bandwidth of the connection is equal to the its effective bandwidth. Expressions of virtual effective bandwidth for each specific capacity subregion under different QoS limits have been derived. These limits include average queue length, the second..

Lay prototypes of illness among a Northern Sotho community in South Africa

Illness representations have been shown to differ across cultures. The aim of the study was to study disease terminology and lay prototypes among a Northern Sotho community in South Africa. The sample for a free listing of disease terms included 41 (55%) women and 34 (45%) men, with a mean age of 36 years (SD=5.6, range 18 to 75 years). The sample for pile sorting of disease terms included 80 Northern Sotho-speaking third-year students from the University of Limpopo; 44 women, 36 men, mean age, 23.4 years (SD=3.4). From free listing of disease terms 50 were selected for pile sorting. Using hierarchical cluster analysis the following clusters could be identified: (1) respiratory problems, (2) internal body problems and sexually transmitted diseases, (3) chronic diseases and head diseases, (4) child diseases and mental problems, (5) child diseases and cancer, (6) feet problems, (7) gastrointestinal diseases. There was homogeneity of features within cluster and difference between clusters.

Characterisation of rainfall at a semi-arid ecotope in the Limpopo Province (South Africa) and its implications for sustainable crop production

Detailed knowledge of rainfall regime is an important prerequisite for agricultural planning. Despite the importance of rain-fed agriculture to food security in the semi-arid regions of South Africa, studies to understand the spatial and temporal variability of rainfall are not widely documented. Twenty-three years (1983 to 2005) of rainfall data were analysed in order to study the basic statistical rainfall characteristics at the University of Venda ecotope. Annual and monthly rainfall was fitted to theoretical probability distributions. The Anderson-Darling goodness-of-fit test was used to evaluate best fit models. Probability of receiving annual and monthly rainfall was predicted using the appropriate probability distribution functions. The chance of experiencing dry spells of different durations was determined. Cumulative frequency analysis of daily rainfall amounts and depths was characterized. It was found that the distribution of daily rainfall was highly skewed with high frequency of occurrence of low-rainfall events. The distribution of daily rainfall depths was also highly skewed,a comparatively small proportion of rainy days supplying a high proportion of the rainfall

Economy Structure, Productivity And Economic Growth: Towards Methodological Perspective

As economic sectors’ performance targeted at country’s economic growth through the prism of inputs to production can not be implied without productivity phenomenon in the context of sustainable development, this paper is purposed to provide one aspect of the relevant methodologies for productivity phenomenon evaluation in the structure of economy. Scrutinized scientific literature proposes the following possible perceptions of productivity targets: as labor moves from low to high productivity a sector, in such a way contributing to aggregate country’s productivity growth, and as productivity increasement within sectors. Different variations of shift-share analysis methods have been provided to measure the impact of structural change on aggregate productivity growth