172 resultados para Variational Convergence
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In the past decade, policymakers in over 70 markets have introduced corporate governance codes or best practice guidelines. In East Asia, they have been introduced in Hong Kong in 1999 and 2006, Indonesia in 2000 and 2007, Malaysia in 2000 and 2007, the Philippines in 2002, Singapore iu 2001 and 2005, South Korea in 2003, Taiwan iu 2002 and Thailand iu 2006. The common focus of these codes is to encourage but not force companies to improve their corporate governance practices to a specified target level, e.g., board independence of 30%. Another commonality is that the guidelines apply to all listed companies regardless of their ownership structure or other characteristics.
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This paper analyses recent corporate governance codes issued by 20 countries for evidence of convergence in corporate governance systems in Europe. The analysis shows that there has been a degree of convergence towards an Anglo-Saxon model of corporate governance as the audit committee concept is widely accepted in countries with both unitary and two-tier governance systems. Further, the latest audit committee recommendations in countries that have issued several governance codes show a strengthening of the recommendations for an audit committee over time in line with the Anglo-Saxon audit committee concept and convergence with the debate in the US and UK on issues such as the independence and financial expertise of members. However, consistent with the literature on the convergence of European corporate governance systems, at an operational level there is limited consistency in the recommended structure and role of audit committees.
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This paper presents an extension to the Rapidly-exploring Random Tree (RRT) algorithm applied to autonomous, drifting underwater vehicles. The proposed algorithm is able to plan paths that guarantee convergence in the presence of time-varying ocean dynamics. The method utilizes 4-Dimensional, ocean model prediction data as an evolving basis for expanding the tree from the start location to the goal. The performance of the proposed method is validated through Monte-Carlo simulations. Results illustrate the importance of the temporal variance in path execution, and demonstrate the convergence guarantee of the proposed methods.
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In this paper, we consider a two-sided space-fractional diffusion equation with variable coefficients on a finite domain. Firstly, based on the nodal basis functions, we present a new fractional finite volume method for the two-sided space-fractional diffusion equation and derive the implicit scheme and solve it in matrix form. Secondly, we prove the stability and convergence of the implicit fractional finite volume method and conclude that the method is unconditionally stable and convergent. Finally, some numerical examples are given to show the effectiveness of the new numerical method, and the results are in excellent agreement with theoretical analysis.
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Purpose To investigate the frequency of convergence and accommodation anomalies in an optometric clinical setting in Mashhad, Iran, and to determine tests with highest accuracy in diagnosing these anomalies. Methods From 261 patients who came to the optometric clinics of Mashhad University of Medical Sciences during a month, 83 of them were included in the study based on the inclusion criteria. Near point of convergence (NPC), near and distance heterophoria, monocular and binocular accommodative facility (MAF and BAF, respectively), lag of accommodation, positive and negative fusional vergences (PFV and NFV, respectively), AC/A ratio, relative accommodation, and amplitude of accommodation (AA) were measured to diagnose the convergence and accommodation anomalies. The results were also compared between symptomatic and asymptomatic patients. The accuracy of these tests was explored using sensitivity (S), specificity (Sp), and positive and negative likelihood ratios (LR+, LR−). Results Mean age of the patients was 21.3 ± 3.5 years and 14.5% of them had specific binocular and accommodative symptoms. Convergence and accommodative anomalies were found in 19.3% of the patients; accommodative excess (4.8%) and convergence insufficiency (3.6%) were the most common accommodative and convergence disorders, respectively. Symptomatic patients showed lower values for BAF (p = .003), MAF (p = .001), as well as AA (p = .001) compared with asymptomatic patients. Moreover, BAF (S = 75%, Sp = 62%) and MAF (S = 62%, Sp = 89%) were the most accurate tests for detecting accommodative and convergence disorders in terms of both sensitivity and specificity. Conclusions Convergence and accommodative anomalies are the most common binocular disorders in optometric patients. Including tests of monocular and binocular accommodative facility in routine eye examinations as accurate tests to diagnose these anomalies requires further investigation.
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Research question / issue This paper frames the debate on corporate governance convergence in terms of the morality underlying corporate governance models. The claims and arguments of moral relativism are presented to provide theoretical structure to the moral aspects of corporate governance convergence, and ultimately the normative question of whether convergence should occur. Research findings / insights: The morality underlying different models of corporate governance has largely been ignored in the corporate governance convergence literature. A range of moral philosophies and principles that underlie the dominant corporate governance models are identified. This leads to a consideration of the claims and arguments of moral relativism relating to corporate governance. A research agenda around the claims of Descriptive and Metaethical moral relativism, and which ultimately informs the associated normative argument, is then suggested. Theoretical / Academic implications The application of moral relativism to the debate on corporate governance convergence presents a theoretical structure to the analysis and consideration of its moral aspects. This structure lends itself to further research, both empirical and conceptual. Practitioner / Policy implications The claims and arguments of moral relativism provide a means of analysing calls that are made for a culturally or nationally ‘appropriate’ model of corporate governance. This can assist in providing direction for corporate governance reforms and is of particular relevance for developing countries which have inherited Western corporate governance models through colonialism.
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A new transdimensional Sequential Monte Carlo (SMC) algorithm called SM- CVB is proposed. In an SMC approach, a weighted sample of particles is generated from a sequence of probability distributions which ‘converge’ to the target distribution of interest, in this case a Bayesian posterior distri- bution. The approach is based on the use of variational Bayes to propose new particles at each iteration of the SMCVB algorithm in order to target the posterior more efficiently. The variational-Bayes-generated proposals are not limited to a fixed dimension. This means that the weighted particle sets that arise can have varying dimensions thereby allowing us the option to also estimate an appropriate dimension for the model. This novel algorithm is outlined within the context of finite mixture model estimation. This pro- vides a less computationally demanding alternative to using reversible jump Markov chain Monte Carlo kernels within an SMC approach. We illustrate these ideas in a simulated data analysis and in applications.
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Particle Swarm Optimization (PSO) is a biologically inspired computational search and optimization method based on the social behaviors of birds flocking or fish schooling. Although, PSO is represented in solving many well-known numerical test problems, but it suffers from the premature convergence. A number of basic variations have been developed due to solve the premature convergence problem and improve quality of solution founded by the PSO. This study presents a comprehensive survey of the various PSO-based algorithms. As part of this survey, the authors have included a classification of the approaches and they have identify the main features of each proposal. In the last part of the study, some of the topics within this field that are considered as promising areas of future research are listed.
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In order to progress beyond currently available medical devices and implants, the concept of tissue engineering has moved into the centre of biomedical research worldwide. The aim of this approach is not to replace damaged tissue with an implant or device but rather to prompt the patient's own tissue to enact a regenerative response by using a tissue-engineered construct to assemble new functional and healthy tissue. More recently, it has been suggested that the combination of Synthetic Biology and translational tissue-engineering techniques could enhance the field of personalized medicine, not only from a regenerative medicine perspective, but also to provide frontier technologies for building and transforming the research landscape in the field of in vitro and in vivo disease models.
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We propose an iterative estimating equations procedure for analysis of longitudinal data. We show that, under very mild conditions, the probability that the procedure converges at an exponential rate tends to one as the sample size increases to infinity. Furthermore, we show that the limiting estimator is consistent and asymptotically efficient, as expected. The method applies to semiparametric regression models with unspecified covariances among the observations. In the special case of linear models, the procedure reduces to iterative reweighted least squares. Finite sample performance of the procedure is studied by simulations, and compared with other methods. A numerical example from a medical study is considered to illustrate the application of the method.
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"The book brings together experts from Media and Communication Studies with Postcolonial Studies scholars to illustrate how the two fields may challenge and enrich each other. Its essays introduce readers to selected topics including »Media Convergence«, »Transcultural Subjectivity«, »Hegemony«, »Piracy« and »Media History and Colonialism«. Drawing on examples from film, literature, music, TV and the internet, the contributors investigate the transnational dimensions in today's media, engage with local and global media politics and discuss media outlets as economic agents, thus illustrating mechanisms of power in postcolonial and neo-colonial mediascapes."--Publisher website
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Despite positive testing in animal studies, more than 80% of novel drug candidates fail to proof their efficacy when tested in humans. This is primarily due to the use of preclinical models that are not able to recapitulate the physiological or pathological processes in humans. Hence, one of the key challenges in the field of translational medicine is to “make the model organism mouse more human.” To get answers to questions that would be prognostic of outcomes in human medicine, the mouse's genome can be altered in order to create a more permissive host that allows the engraftment of human cell systems. It has been shown in the past that these strategies can improve our understanding of tumor immunology. However, the translational benefits of these platforms have still to be proven. In the 21st century, several research groups and consortia around the world take up the challenge to improve our understanding of how to humanize the animal's genetic code, its cells and, based on tissue engineering principles, its extracellular microenvironment, its tissues, or entire organs with the ultimate goal to foster the translation of new therapeutic strategies from bench to bedside. This article provides an overview of the state of the art of humanized models of tumor immunology and highlights future developments in the field such as the application of tissue engineering and regenerative medicine strategies to further enhance humanized murine model systems.