674 resultados para Modern portfolio theory


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Two decades after its inception, Latent Semantic Analysis(LSA) has become part and parcel of every modern introduction to Information Retrieval. For any tool that matures so quickly, it is important to check its lore and limitations, or else stagnation will set in. We focus here on the three main aspects of LSA that are well accepted, and the gist of which can be summarized as follows: (1) that LSA recovers latent semantic factors underlying the document space, (2) that such can be accomplished through lossy compression of the document space by eliminating lexical noise, and (3) that the latter can best be achieved by Singular Value Decomposition. For each aspect we performed experiments analogous to those reported in the LSA literature and compared the evidence brought to bear in each case. On the negative side, we show that the above claims about LSA are much more limited than commonly believed. Even a simple example may show that LSA does not recover the optimal semantic factors as intended in the pedagogical example used in many LSA publications. Additionally, and remarkably deviating from LSA lore, LSA does not scale up well: the larger the document space, the more unlikely that LSA recovers an optimal set of semantic factors. On the positive side, we describe new algorithms to replace LSA (and more recent alternatives as pLSA, LDA, and kernel methods) by trading its l2 space for an l1 space, thereby guaranteeing an optimal set of semantic factors. These algorithms seem to salvage the spirit of LSA as we think it was initially conceived.

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The business environment across the globe is today characterised by three primary governance arrangements - bureaucracies, markets and networks. For organisations operating within each of these business contexts the terms of engagement in regard to negotiation are different. Rather than starting from a broad ‘how to’ approach or a specific cultural interface, Negotiating the Business Environment looks at governance arrangements within the business environment and at how such governance arrangements impact on how negotiation occurs. This text provides an Australian—not an overseas—perspective on negotiations that will be a welcome change for Australian students. Uniquely, it takes into account the context in which negotiations take place. Negotiating the Business Environment demonstrates how responding to business style in negotiations can effect successful outcomes. It include strong pedagogy including: key terms, key points, further reading lists, case studies, and end of chapter questions

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Crowdsourcing harnesses the potential of large and open networks of people. It is a relatively new phenomenon and attracted substantial interest in practice. Related research, however, lacks a theoretical foundation. We propose a system-theoretical perspective on crowdsourcing systems to address this gap and illustrate its applicability by using it to classify crowdsourcing systems. By deriving two principal dimensions from theory, we identify four fundamental types of crowdsourcing systems that help to distinguish important features of such systems. We analyse their respective characteristics and discuss implications and requirements for various aspects related to the design of such systems. Our results demonstrate that systems theory can inform the study of crowdsourcing systems. The identified system types and the implications on their design may prove useful for researchers to frame future studies and for practitioners to identify the right crowdsourcing systems for a particular purpose.

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This chapter introduces different theoretical approaches to negotiation and provides an explanation of these differing frameworks. While the action of a negotiation centres on the background research undertaken and what happens at the negotiation table, there is a need to know what principles and assumptions are informing these activities. Theories offer a way of understanding the underlying structures, processes and relationships of negotiation. Further, negotiation theories also assist with focusing attention on the 'basis of the bargain' and provide a standpoint from which to judge offers and counter-offers during the negotiation.

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Overviews of research are clear that bullying occurs in every school, and that there are significant negative physical and mental health outcomes associated with it (Beaty and Alexeyev, 2008; Carter, 2011). As such, it is imperative to develop successful intervention strategies to help students cope with bullying, including the emergent form of cyberbullying. Research suggests, however, that students have a very limited repertoire of strategies for dealing with bullying generally (Owens, Shute, and Slee, 2004). In this paper the authors outline what is currently known about bullying, including cyberbullying, its impact on students, how theory can assist in developing interventions to assist and support students to cope with bullying, and some of the implications for schools.

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Six Sigma is considered to be an important management philosophy to obtain satisfied customers. But financial service organisations have been slow to adopt Six Sigma issues so far. Despite the extensive effort that has been invested and benefits that can be obtained, the systematic implementation of Six Sigma in financial service organisations is limited. As a company wide implementation framework is missing so far, this paper tries to fill this gap. Based on theory, a conceptual framework is developed and evaluated by experts from financial institutions. The results show that it is very important to link Six Sigma with the strategic as well as the operations level. Furthermore, although Six Sigma is a very important method for improving quality of processes others such as Lean Management are also used This requires a superior project portfolio management to coordinate resources and projects of Six Sigma with the other methods used. Beside the theoretical contribution, the framework can be used by financial service companies to evaluate their Six Sigma activities. Thus, the framework grounded through literature and empirical data will be a useful guide for sustainable and successful implementation of a Six Sigma initiative in financial service organisations.

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With the growth and development of communication technology there is an increasing need for the use of interception technologies in modern policing. Law enforcement agencies are faced with increasingly sophisticated and complex criminal networks that utilise modern communication technology as a basis for their criminal success. In particular, transnational organised crime (TOC) is a diverse and complicated arena, costing global society in excess of $3 trillion annually, a figure that continues to grow (Borger, 2007) as crime groups take advantage of disappearing borders and greater profit markets. However, whilst communication can be a critical success factor for criminal enterprise it is also a key vulnerability. It is this vulnerability that the use of CIT, such as phone taps or email interception, can exploit. As such, law enforcement agencies now need a method and framework that allows them to utilise CIT to combat these crimes efficiently and successfully. This paper provides a review of current literature with the specific purpose of considering the effectiveness of CIT in the fight against TOC and the groundwork that must be laid in order for it to be fully exploited. In doing so, it fills an important gap in current research, focusing on the practical implementation of CIT as opposed to the traditional area of privacy concerns that arise with intrusive methods of investigation. The findings support the notion that CIT is an essential intelligence gathering tool that has a strong place within the modern policing arena. It identifies that the most effective use of CIT is grounded within a proactive, intelligence‐led framework and concludes that in order for this to happen Australian authorities and law enforcement agencies must re‐evaluate and address the current legislative and operational constraints placed on the use of CIT and the culture that surrounds intelligence in policing.

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Various researchers have called for an 'opening up' of Luhmann's systems theory. We take this short paper as an occasion for a critical reflection on the necessity, existence and possibilities of such an opening. We start by pointing out the inherent openness of Luhmann's theory, and, based on this, discuss three kinds of openings: the international opening, the theoretical opening and the empirical opening. With regard to the latter, we distinguish three general options of using Luhmann's theory for empirical research. Copyright © 2007 SAGE.

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Business transformations are large-scale organisational change projects that, evidence suggests, are often unsuccessful. This study aims to develop a conceptual model that explains how management services that are required for a business transformation are orchestrated during such a initiative. We classify management services such as (but not limited to) change management, risk management, IT management, financial management, program management and so forth as bearing transformational and/or transactional capabilities in a transformation initiative. We then draw upon three principles of musical composition, namely melody, harmony and rhythm, and illustrate how they apply to the orchestration of management services in the management of business transformations. In order to illustrate our emerging model, we examine the case of Malaysia Airlines, who have managed to successfully turnaround the near-bankrupt organisation beyond survival. We demonstrate how the notions of melody, harmony and rhythm can be used to describe their endeavour. We conclude by discussing next steps of our research.

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The editor, Gerard de Valence, points out in the preface, this book is neither a textbook nor a guide to what is done by construction managers and construction economists – read quantity surveyors and the like. Rather, de Valence notes it comprises a collection of chapters each of which focus on matters at the industry level and, in doing so, illustrates that a substantially improved understanding of the building and construction industry can be gained beyond the economics of delivering projects. Before giving some thought to how far each of the chapters achieve this, it’s worth reflecting on the virtues of developing construction economics as its own discipline or sub-discipline in general economics and the bold manner by which de Valence is proposing we do this. That is, de Valence proposes partitioning industry and project economics - as explained in the preface and in Chapter 1. de Valence’s view that “the time seems right” for these developments is also worthy of some consideration.

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In its earliest and simplest form queer theory proposes that sexual identity is not essential, but socially constructed, and understandings of identity, gender and sexuality are constructed differently at different times and in different places. Queer theory aims to challenge normative understandings of sex, sexuality and gender, and also normative concepts of knowledge and being. Since its inception, queer theory has been taken up by a number of disciplines as an analytical framework. These include cultural geography, education studies, film studies and sociology. In the last decade queer theory has been used to consider citizenship, diasporas and post colonial experiences. A queer theoretical perspective has also been used to analyse emotions, the Death Drive, phenomenology, and disability. As queer theory enters its third decade Janet Halley and Andrew Parker ask what is after sex? ‘What has queer theory become now that it has a past?’

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Physical inactivity is a serious concern both nationally and internationally. Despite the numerous benefits of performing regular physical activity, many individuals lead sedentary lifestyles. Of concern, though, is research showing that some population sub-groups are less likely to be active, such as parents of young children. Although there is a vast amount of research dedicated to understanding people.s physical activity-related behaviours, there is a paucity of research examining those factors that influence parental physical activity. More importantly, research applying theoretical models to understand physical activity decision-making among this at-risk population is limited. Given the current obesity epidemic, the decline in physical activity with parenthood, and the many social and health benefits associated with regular physical activity, it is important that adults with young children are sufficiently active. In light of the dearth of research examining parental physical activity and the scant research applying a theory-based approach to gain this understanding, the overarching aim of the current program of research was to adopt a mixed methods approach as well as use sound theoretical frameworks to understand the regular physical activity behaviour of mothers and fathers with young children. This program of research comprised of three distinct stages: a qualitative stage exploring individual, social, and psychological factors that influence parental regular physical activity (Stage 1); a quantitative stage identifying the important predictors of parental regular physical activity intentions and behaviour using sound theoretical frameworks and testing a single-item measure for assessing parental physical activity behaviour (Stage 2); and a qualitative stage exploring strategies for an intervention program aimed at increasing parental regular physical activity (Stage 3). As a thesis by publication, eight papers report the findings of this program of research; these papers are presented according to the distinct stages of investigation that guided this program of research. Stage One of the research program comprised a qualitative investigation using a focus group/interview methodology with parents of children younger than 5 years of age (N = 40; n = 21 mothers, n = 19 fathers) (Papers 1, 2, and 3). Drawing broadly on a social constructionist approach (Paper 1), thematic analytic methods revealed parents. understandings of physical activity (e.g., requires effort), patterns of physical activity-related behaviours (e.g., grab it when you can, declining physical activity habits), and how constructions of social role expectations might influence parents. physical activity decision making (e.g., creating an active family culture, guilt and selfishness). Drawing on the belief-based framework of the TPB (Paper 2), thematic content analytic methods revealed parents. commonly held beliefs about the advantages (e.g., improves parenting practices), disadvantages (e.g., interferes with commitments), barriers (e.g., time), and facilitators (e.g., social support) to performing regular physical activity. Parents. normative beliefs about social approval from important others or groups (e.g., spouse/partner) were also identified. Guided by theories of social support, Paper Three identified parents. perceptions about the specific social support dimensions that influence their physical activity decision making. Thematic content analysis identified instrumental (e.g., providing childcare, taking over chores), emotional (e.g., encouragement, companionship), and informational support (e.g., ideas and advice) as being important to the decision-making of parents in relation to their regular physical activity behaviour. The results revealed also that having support for being active is not straightforward (e.g., guilt-related issues inhibited the facilitative nature of social support for physical activity). Stage Two of the research program comprised a quantitative examination of parents. physical activity intentions and behaviour (Papers 4, 5, 6, and 7). Parents completed an extended TPB questionnaire at Time 1 (N = 580; n = 288 mothers, n = 292 fathers) and self-reported their physical activity at Time 2, 1 week later (N = 458; n = 252 mothers, n = 206 fathers). Paper Four revealed key behavioural (e.g., improving parenting practices), normative (e.g., people I exercise with), and control (e.g., lack of time) beliefs as significant independent predictors of parental physical activity. A test of the TPB augmented to include the constructs of self-determined motivation and planning was assessed in Paper Five. The findings revealed that the effect of self-determined motivation on intention was fully mediated by the TPB variables and the impact of intention on behaviour was partially mediated by the planning variables. Slight differences in the model.s motivational sequence between the sexes were also noted. Paper Six investigated, within a TPB framework, a range of social influences on parents. intentions to be active. For both sexes, attitude, perceived behavioural control, group norms, friend general support, and an active parent identity predicted intentions, with subjective norms and family support further predicting mothers. intentions and descriptive norms further predicting fathers. intentions. Finally, the measurement of parental physical activity was investigated in Paper Seven of Stage Two. The results showed that parents are at risk of low levels of physical activity, with the findings also revealing validation support for a brief single-item physical activity measure. Stage Three of the research program comprised a qualitative examination of parents. (N = 12; n = 6 mothers, n = 6 fathers) ideas for strategies that may be useful for developing and delivering an intervention program aimed at increasing parental physical activity (Paper 8). Parents revealed a range of strategies for what to include in a physical activity intervention designed for parents of young children. For example, parents identified persuasion and information type messages, problem-solving strategies that engage parents in generating a priority list of their lifestyle commitments, and behavioural modification techniques such as goal setting and incentives. Social intervention strategies (e.g., social comparison, counselling) and environmental approaches (e.g., community-based integrative parent/child programs) were also identified as was a skill-based strategy in helping parents generate a flexible life/family plan. Additionally, a range of strategies for how to best deliver a parental physical activity intervention was discussed. Taken as a whole, Paper Eight found that adopting a multifaceted approach in both the design and implementation of a resultant physical activity intervention may be useful in helping to increase parental physical activity. Overall, this program of research found support for parents as a unique group who hold both similar and distinctive perceptions about regular physical activity to the general adult population. Thus, these findings highlight the importance of targeting intervention strategies for parents of young children. Additionally, the findings suggest that it might also be useful to tailor some messages specifically to each sex. Effective promotion of physical activity in parents of young children is essential given the low rate of activity in this population. Results from this program of research highlight parents as an at-risk group for inactivity and provide an important first step in identifying the factors that influence both mothers. and fathers. physical activity decision making. These findings, in turn, provide a foundation on which to build effective intervention programs aimed at increasing parents. regular physical activity which is essential for ensuring the health and well-being of parents with young children.

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This catalogue essay discusses the work of contemporary Brisbane artist Grant Stevens. It provides a survey of his video work and discusses the artist's use of cliche and other mediated formulas to explore the nature of media and its impact on consciousness in the early 21st century.

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This position paper provides an overview of work conducted and an outlook of future directions within the field of Information Retrieval (IR) that aims to develop novel models, methods and frameworks inspired by Quantum Theory (QT).