Impact of Self-generation of Priorities and Non-preemptive Service in Single/Multiserver Queues

In this thesis we have studied a few models involving self-generation of priorities. Priority queues have been extensively discussed in literature. However, these are situations involving priority assigned to (or possessed by) customers at the time of their arrival. Nevertheless, customers generating into priority is a common phenomena. Such situations especially arise at a physicians clinic, aircrafts hovering over airport running out of fuel but waiting for clearance to land and in several communication systems. Quantification of these are very little seen in literature except for those cited in some of the work indicated in the introduction. Our attempt is to quantify a few of such problems. In doing so, we have also generalized the classical priority queues by introducing priority generation ( going to higher priorities and during waiting). Systematically we have proceeded from single server queue to multi server queue. We also introduced customers with repeated attempts (retrial) generating priorities. All models that were analyzed in this thesis involve nonpreemptive service. Since the models are not analytically tractable, a large number of numerical illustrations were produced in each chapter to get a feel about the working of the systems.

Analytical Studies on Diffusion and lntermittency in Chaotic Maps

The study of simple chaotic maps for non-equilibrium processes in statistical physics has been one of the central themes in the theory of chaotic dynamical systems. Recently, many works have been carried out on deterministic diffusion in spatially extended one-dimensional maps This can be related to real physical systems such as Josephson junctions in the presence of microwave radiation and parametrically driven oscillators. Transport due to chaos is an important problem in Hamiltonian dynamics also. A recent approach is to evaluate the exact diffusion coefficient in terms of the periodic orbits of the system in the form of cycle expansions. But the fact is that the chaotic motion in such spatially extended maps has two complementary aspects- - diffusion and interrnittency. These are related to the time evolution of the probability density function which is approximately Gaussian by central limit theorem. It is noticed that the characteristic function method introduced by Fujisaka and his co-workers is a very powerful tool for analysing both these aspects of chaotic motion. The theory based on characteristic function actually provides a thermodynamic formalism for chaotic systems It can be applied to other types of chaos-induced diffusion also, such as the one arising in statistics of trajectory separation. It was noted that there is a close connection between cycle expansion technique and characteristic function method. It was found that this connection can be exploited to enhance the applicability of the cycle expansion technique. In this way, we found that cycle expansion can be used to analyse the probability density function in chaotic maps. In our research studies we have successfully applied the characteristic function method and cycle expansion technique for analysing some chaotic maps. We introduced in this connection, two classes of chaotic maps with variable shape by generalizing two types of maps well known in literature.

Nuclear incompressibility in the quasilocal density functional theory

We explore the ability of the recently established quasilocal density functional theory for describing the isoscalar giant monopole resonance. Within this theory we use the scaling approach and perform constrained calculations for obtaining the cubic and inverse energy weighted moments (sum rules) of the RPA strength. The meaning of the sum rule approach in this case is discussed. Numerical calculations are carried out using Gogny forces and an excellent agreement is found with HF+RPA results previously reported in literature. The nuclear matter compression modulus predicted in our model lies in the range 210230 MeV which agrees with earlier findings. The information provided by the sum rule approach in the case of nuclei near the neutron drip line is also discussed.

Marine yeast Candida MCCF 101 as feed supplement in aquaculture: nutritional quality, optimization of large scale production and evaluation of its protective effect on Koi carp from Aeromonas infection

Marine yeast have been regarded as safe and showing a beneficial impact on biotechnological process. It provides better nutritional and dietary values indicating their potential application as feed supplements in aquaculture. Brown et al. (1996) evaluated all the marine yeasts characterised with high protein content, carbohydrate, good amino acid composition and high levels of saturated fats. However, there is paucity of information on marine yeasts as feed supplements and no feed formulation has been found either in literature or in market supplemented with them. This statement supported by Zhenming et al. (2006) reported still a lack of feed composed of single cell protein (SCP) from marine yeasts with high content of protein and other nutrients. Recent research has shown that marine yeasts also have highly potential uses in food, feed, medical and biofuel industries as well as marine biotechnology (Chi et al., 2009; 2010). Sajeevan et al. (2006; 2009a) and Sarlin and Philip (2011) demonstrates that the marine yeasts Candida sake served as a high quality, inexpensive nutrient source and it had proven immunostimulatory properties for cultured shrimps. This strain has been made part of the culture collection of National Centre for Aquatic Animal Health, Cochin University of Science and Technology as Candida MCCF 101. Over the years marine yeasts have been gaining increased attention in animal feed industry due to their nutritional value and immune boosting property.Therefore, the present study was undertaken, and focused on the nutritional quality, optimization of large scale production and evaluation of its protective effect on Koi carp from Aeromonas infection

[Ressenya del llibre The Desert is no lady: southwestern landscapes in women's writing and art, de Vera Norwood i Janice Monk (ed.)]

Ressenya del llibre The Desert is no lady: southwestern landscapes in women's writing and art, obra on s’interrelacionen tres temes que són paisatge, gènere (en aquest cas, la dona) i literatura (i, per extensió, un quart que és l’art)

A survey on voltage sag events in power systems

This paper aims to survey the techniques and methods described in literature to analyse and characterise voltage sags and the corresponding objectives of these works. The study has been performed from a data mining point of view

Pathomechanics of posterior ankle impingement syndrome in female ballet dancers

A dança é uma actividade de grande exigência atlética, que pode conduzir a um elevado número de lesões, particularmente na região do tornozelo, possivelmente devido à amplitude extrema do movimento articular de flexão plantar do mesmo, que os bailarinos, especialmente do sexo feminino possuem, para realizar a ponta e meia ponta tão características do ballet clássico (Kadel, 2006; Motta-Valencia, 2006; Russel, Kruse, Koutedakis, McEwan, Wyon, 2010). Estas posições de flexão plantar extrema produzem força excessiva na região posterior do tornozelo, o que muitas vezes pode resultar em conflito, dor e incapacidade, representando na maioria das vezes um desafio de diagnóstico. O síndrome do conflito posterior do tornozelo refere-se a um grupo de entidades patológicas que resultam da flexão plantar forçada do tornozelo, de forma repetitiva ou traumática, causando um conflito das estruturas ósseas e/ou de tecidos moles (Hamilton, Geppert, Thompson, 1996; Hamilton, 2008) . Os objectivos deste projecto são compreender os quais os factores de risco, mecânicos e funcionais que contribuem para a mecânica patológica da lesão descritos na literatura, e proceder a uma avaliação biomecânica do movimento de flexão plantar do tornozelo. Método. Realizar uma revisão sistemática de literatura dirigida á mecânica patológica do síndrome do conflito posterior do tornozelo em bailarinas e conduzir um estudo caso-controlo, cujo objectivo é avaliar, comparar e descrever o movimento da flexão plantar do tornozelo realizado ao efectuar os movimentos de ponta e meia-ponta, em bailarinas pré-profissionais com e sem lesão recorrente resultante do conflito posterior do tornozelo. Resultados. Não foram encontrados estudos relacionados especificamente com a mecânica patológica do tornozelo, no entanto vários estudos foram encontrados considerando as características clínicas e anatómicas assim como os procedimentos de tratamento, indicando que os principais factores de risco relacionados com a lesão se dividem em factores mecânicos e funcionais que quando combinados entre si e associados ao sobre-uso podem resultar no conflito posterior do tornozelo. Na avaliação do movimento foram observadas diferenças na actividade muscular entre os sujeitos com lesão e controlos, tendo sido possível a observação de um padrão na sequência de activação para um dos movimentos testados. Na oscilação postural e na rigidez do tornozelo foram também observadas diferenças entre os sujeitos bem como entre as posições realizadas. Conclusão. Concluiu-se que não sendo possível alterar a anatomia do bailarino, por vezes é possível intervir a nível funcional melhorando a capacidade técnica de forma obter um melhor desempenho e a actuar preventivamente em relação às lesões, uma vez que estas podem apresentar padrões cinéticos próprios, relacionados com a função muscular, a estabilidade postural e a rigidez articular.

Playing with history: negotiating subjectivity in contemporary lens based work

Contemporary artists exploring Jewish identity in the UK are caught between two exclusions, broadly speaking: an art community that that sees itself as ‘post –identity’ and a ‘black’ art scene that revolves around the organizations that emerged out of the Identity debates of the 1980s and 1990s, namely Iniva, Third Text, Autograph. These organizations and those debates, don’t usually include Jewish identity within their remit as Jewish artists are considered to be well represented in the British art scene and, in any case, white. Out of these assumptions, questions arise in relation to the position of Jews in Britain and what is at stake for an artist in exploring Jewish Identity in their work. There is considerable scholarship, relatively speaking on art and Jewish Identity in the US (such as Lisa Bloom; Norman Kleeblatt; Catherine Sousslouf), which inform the debates on visual culture and Jews. In this chapter, I will be drawing out some of the distinctions between the US and the UK debates within my analysis, building on my own writing over the last ten years as well as the work of Juliet Steyn, Jon Stratton and Griselda Pollock. In short, this chapter aims to explore the problematic of what Jewish Identity can offer the viewer as art; what place such art inhabits within a wider artistic context and how, if at all, it is received. There is a predominance of lens based work that explores Identity arising out of the provenance of feminist practices and the politics of documentary that will be important in the framing of the work. I do not aim to consider what constitutes a Jewish artist, that has been done elsewhere and is an inadequate and somewhat spurious conversation . I will also not be focusing on artists whose intention is to celebrate an unproblematised Jewishness (however that is constituted in any given work). Recent artworks and scholarship has in any case rendered the trumpeting of attachment to any singular identity anachronistic at best. I will focus on artists working in the UK who incorporate questions of Jewishness into a larger visual enquiry that build on Judith Butler’s notion of identity as process or performative as well as the more recent debates and artwork that consider the intersectionality of identifications that co-constitute provisional identities (Jones, Modood, Sara Ahmed, Braidotti/Nikki S Lee, Glenn Ligon). The case studies to think through these questions of identity, will be artworks by Susan Hiller, Doug Fishbone and Suzanne Triester. In thinking through works by these artists, I will also serve to contextualise them, situating them briefly within the history of the landmark exhibition in the UK, Rubies and Rebels and the work of Ruth Novaczek, Lily Markewitz, Oreet Ashery and myself.

Imagining multicultural London: containment and excess in snatch

Snatch (Guy Ritchie, 2000) is a comic-book gangster film that can be seen to represent the backlash against perceived notions of political correctness in what is effectively a public-schoolboy fantasy of working-class life in East London. However, the film also delineates the limits of this backlash in its depiction of minorities as either contained or excess. This is highlighted through the comic-book genre itself as well as the characterization. Thus this article explores the tension between the genre, representation and Jewish identity.

Papal power and protection in the Shebet Yehudah

The sixteenth-century Shebet Yehudah is an account of the persecutions of Jews in various countries and epochs, including their expulsion from Spain in the fifteenth century. It is not a medieval text and was written long after many of the events it describes. Yet although it cannot give us a contemporary medieval standpoint, it provides important insights into how later Jewish writers perceived Jewish–papal relations in the thirteenth, fourteenth, and fifteenth centuries. Although the extent to which Jewish communities came into contact either with the papacy as an institution or the actions of individual popes varied immensely, it is through analysis of Hebrew works such as the Shebet Yehudah that we are able to piece together a certain understanding of Jewish ideas about the medieval papacy as an institution and the policies of individual popes. This article argues that Jews knew only too well that papal protection was not unlimited, but always carefully circumscribed in accordance with Christian theology. It is hoped that it will be a scholarly contribution to our growing understanding of Jewish ideas about the papacy's spiritual and temporal power and authority in the Later Middle Ages and how this impacted on Jewish communities throughout medieval Europe.

Equations to predict methane emissions from cows fed at maintenance energy level in pasture-based systems

Ruminant production is a vital part of food industry but it raises environmental concerns, partly due to the associated methane outputs. Efficient methane mitigation and estimation of emissions from ruminants requires accurate prediction tools. Equations recommended by international organizations or scientific studies have been developed with animals fed conserved forages and concentrates and may be used with caution for grazing cattle. The aim of the current study was to develop prediction equations with animals fed fresh grass in order to be more suitable to pasture-based systems and for animals at lower feeding levels. A study with 25 nonpregnant nonlactating cows fed solely fresh-cut grass at maintenance energy level was performed over two consecutive grazing seasons. Grass of broad feeding quality, due to contrasting harvest dates, maturity, fertilisation and grass varieties, from eight swards was offered. Cows were offered the experimental diets for at least 2 weeks before housed in calorimetric chambers over 3 consecutive days with feed intake measurements and total urine and faeces collections performed daily. Methane emissions were measured over the last 2 days. Prediction models were developed from 100 3-day averaged records. Internal validation of these equations, and those recommended in literature, was performed. The existing in greenhouse gas inventories models under-estimated methane emissions from animals fed fresh-cut grass at maintenance while the new models, using the same predictors, improved prediction accuracy. Error in methane outputs prediction was decreased when grass nutrient, metabolisable energy and digestible organic matter concentrations were added as predictors to equations already containing dry matter or energy intakes, possibly because they explain feed digestibility and the type of energy-supplying nutrients more efficiently. Predictions based on readily available farm-level data, such as liveweight and grass nutrient concentrations were also generated and performed satisfactorily. New models may be recommended for predictions of methane emissions from grazing cattle at maintenance or low feeding levels.

Evaluation of phenolic compounds in mate (Ilex paraguariensis) processed by gamma radiation

The radiation food processing has been demonstrating great effectiveness in the attack of pathogenic agents, while little compromising nutritional value and sensorial properties of foods. The mate (Ilex paraguariensis), widely consumed product in South America, generally in the form of infusions with hot or cold water, calls of chimarrao or terere, it is cited in literature as one of the best sources phenolic compounds. The antioxidants action of these constituent has been related to the protection of the organism against the free radicals, generated in alive, currently responsible for the sprouting of some degenerative illness as cancer, arteriosclerosis, rheumatic arthritis and cardiovascular clutters among others. The objective of that work was to evaluate the action of the processing for gamma radiation in phenolic compounds of terere beverage in the doses of 0, 3, 5, 7 and 10 kGy. The observed results do not demonstrate significant alterations in phenolic compounds of terere beverage processed by gamma radiation. Crown Copyright (C) 2009 Published by Elsevier Ltd. All rights reserved.

Chemical and radiological characterization of clay minerals used in pharmaceutics and cosmetics

Since the early days, clays have been used for therapeutic purposes. Nowadays, they are used as active ingredients or as excipient in formulations for a variety of purposes. Despite their wide use, little information is available in literature on their content of trace elements and radionuclides. The purpose of this study was to determine the elements (As, Ba, Br, Cs, Co, Cr, Eu, Fe, Hf, Hg, La, Lu, Rb, Sb, Sc, Sm, Ta, Tb, Yb, Zn, and Zr) and the radionuclides ((238)U, (232)Th, (226)Ra, (228)Ra, (210)Pb and (40)K) in Brazilian clays as well as the health and radiological implications of the use of these clays in pharmaceutical formulations. (C) 2011 Elsevier B.V. All rights reserved.

Generational and cultural indicators of technology and innovation in family business

The internet revolution has affected everybody in some way. Technologies used in business range from telephones to industry-specific machinery. Mostly though, business technology has come to mean the internet. In literature concerning innovation and the adoption of technology in business, research invariably centres on small to medium businesses (SI'v1Es), as these can be defined reasonably easily. Statistics on family businesses are limited, however, because family businesses are so difficult to categorize and define.

The Australian Family Business Survey of 1993 (Institute of Chartered Accountants) determined that family business is the largest form of business ownership in Australia and represents 83% of all business enterprises, although Basu (2004) believes that over two thirds of all world-wide businesses are owned or managed by families and around half of all businesses in Australia are family businesses. The Australian Institute of Management (AIM) (2004) states that the wealth of family and private businesses is estimated at $3.6 trillion and that family firms generate 50 per cent of Australia's employment growth, account for 40 per cent of Australia's private sector output, and are a seed bed for innovation and the information of large companies.

The difficulty in defining a family business is heightened because family businesses can take many forms ranging from sole traders to private companies to public companies. Hence, when talking about family business, you could be referring to the sole trader dealing with organic produce to an IT organisation employing hundreds of staff. Basu (2004) thinks that while ordinarily, in non-family businesses, the business and family domains remain separate, the key distinctive characteristic of family businesses is that family members work together for economic purposes. In other words, the family is not merely a social unit but also an economic unit. Craig and Lindsay (2002) believe that family involvement in the business is what makes the family business different... researchers, however, cannot seem to agree as to what constitutes 'family involvement' in a business so that it can be defined as a family business and that family business is ... a business that is governed and/or managed with the intention to shape and pursue the vision of the business held by a dominant coalition that is controlled by members of the same family or a small number of families in a manner that is potentially sustainable across generations of the family or families.