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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

On Resource Optimization and Robust CQI Reporting for Wireless Communication Systems.

Ahmad, Ayaz 09 December 2011 (has links) (PDF)
Adaptive resource allocation in wireless communication systems is crucial in order to support the diverse QoS needs of the services and optimize resource utilization. The design of resource allocation schemes should consider the service type for which it is intended. Moreover, due to feedback delay and channel estimation error, the Channel Quality Indicator (CQI) reported to the transmitter may not be a perfect measure of the channel quality and its use for resource allocation may severely degrade the systems performance. In this thesis, we study resource allocation and CQI reporting for wireless networks while taking the aforementioned factors into consideration. First, we consider resource allocation and adaptive modulation in uplink SC-FDMA systems. This is a combinatorial problem whose optimal solution is exponentially complex. We use canonical duality theory to derive a polynomial complexity resource allocation algorithm that provides a nearly optimal solution to the problem. Then, we focus on resource allocation for video streaming in wireless networks with time-varying interference. To this end, by using risk-sensitive control approach, we develop a cross-layer optimization framework that performs power control at the PHY/MAC layer and rate adaptation at the APPLICATION layer jointly and provides fairness among nodes. Finally, by using stochastic control and game theory, we design a robust best-M CQI reporting scheme for multi-carrier and multi-user systems which takes into account the impact of feedback delay and error in CQI computation. Performing resource allocation on the basis of the proposed CQI reporting can significantly improve the system performance.
212

An Empirical Evaluation of Human Figure Tracking Using Switching Linear Models

Patrick, Hugh Alton, Jr. 19 November 2004 (has links)
One of the difficulties of human figure tracking is that humans move their bodies in complex, non-linear ways. An effective computational model of human motion could therefore be of great benefit in figure tracking. We are interested in the use of a class of dynamic models called switching linear dynamic systems for figure tracking. This thesis makes two contributions. First, we present an empirical analysis of some of the technical issues involved with applying linear dynamic systems to figure tracking. The lack of high-level theory in this area makes this type of empirical study valuable and necessary. We show that sensitivity of these models to perturbations in input is a central issue in their application to figure tracking. We also compare different types of LDS models and identification algorithms. Second, we describe 2-DAFT, a flexible software framework we have created for figure tracking. 2-DAFT encapsulates data and code involved in different parts of the tracking problem in a number of modules. This architecture leads to flexibility and makes it easy to implement new tracking algorithms.
213

Study of Professional Medical Personnel's Awareness & Attitude of Knowledge Management

Huang, Yih-Sheng 19 July 2001 (has links)
In an information era of new knowledge-based economy, how should the traditional medical industry respond? Do medical professionals have any awareness of knowledge management? If yes, what is their attitude towards knowledge? What are the features? Based on the infusion methodology of knowledge management, if a hospital seeks to adopt an information system for knowledge management (KM), the hospital will have to go through the process of integrating the strategy, the process, the information technology and the awareness of the people and the organization. Subjects of this study were medical professionals, and Arthur Andersen¡¦s knowledge management model was taken as reference. The structure of the study is divided into two sections, i.e. ¡§employees¡¦ awareness of knowledge management¡¨ and ¡§employees¡¦ awareness of the hospital¡¦s knowledge management¡¨. In the former section, factor analysis reveals that medical professionals tend to view knowledge management as the planning and integration of personal knowledge management. Medical professionals recognize that knowledge is an important personal asset, and some inexpressible tacit knowledge still exists in one¡¦s knowledge that needs to be valued. Furthermore, they also believe that in order to increase the value of knowledge assets, it is necessary to share knowledge. In the latter section, factor analysis reveals that medical professionals recognize that a hospital should have a properly planned process to gain knowledge and should create an innovative and practical environment to accumulate knowledge-based assets for the hospital. As for personal property, in the section of ¡§employees¡¦ awareness of knowledge management¡¨, the study manifests obvious difference on the variables of personal property which includes scale of hospital, age, gender, working years, educational background, type of work and management post. On the other hand, the study shows that in the section of ¡§employees¡¦ awareness of the hospitals¡¦ knowledge management¡¨, there is obvious difference on the variables of personal property including scale of hospital, age, working year, educational background while the property of the gender, type of work and management post remain relatively the same. Moreover, the study also shows that if employees are more satisfied with the self-awareness of knowledge management, they are more likely to agree with every dimensions of the knowledge management of the hospital they work in. On the other hand, if all dimensions of the hospital¡¦s knowledge management are recognized by the employees, the variable of the self-awareness of knowledge management reflected on the employees will also be positive. This demonstrates that the demand of employee¡¦s personal awareness will be influenced by the working environment, and vice versa. Outstanding employees will affect the operation performance of the hospital. Similarly, a properly managed hospital will enhance the performance of the employees. It is apparent that the two are related to each other from the feature analysis of the study. Thus, if the hospital can invest in improving the structure of the knowledge assets of the hospital and enhance education and propagation, any improvement of the ability of knowledge management of either employers or employees will definitely benefit the other party. In regards to the four elements including the promotion of knowledge management, high-level leadership enterprise culture, information technology and measurement indicators, the canonical correlation analysis and the regression analysis show that the four elements have been highly approved by the medical professionals. In terms of high-level leadership, the establishment of the Chief Knowledge Office (CKO) has been applauded by the employees. At the meantime, the employees¡¦ ability of using computers and the willingness of sharing information have been greatly influenced by the culture of the enterprise. As for information technology, the information reveals the close relationship between the employees¡¦ ability of using computer and the result of the hospital performance of using the information technology. For measurement indicators, in order to make medical professionals recognize the introduction of knowledge management, performance evaluation of all phases of the introduction of knowledge management should be properly conducted. It is recommended by the study to adopt the theory of the balanced scorecard to be the measurement indicators for evaluation the practical performance of the three components of knowledge assets because the framework of both theories are quite similar. Furthermore, the study reveals that employees who have worked longer and who are older will be more likely to recogize the management of knowledge self-supervision and are more willing to share their knowledge. Apparently, when a hospital tries to introduce knowledge management to the employees, it will be more efficient and more effective if the hospital can make full use of the participation of senior employees.
214

Analysis And Design Of Spatial Manipulators : An Exact Algebraic Approach Using Dual Numbers And Symbolic Computation

Bandyopadhyay, Sandipan 04 1900 (has links)
This thesis presents a unified framework for the analysis of instantaneous kinematics and statics of spatial manipulators. The proposed formulation covers the entire range of kinematic behavior, with kinematic singularity and isotropy appearing as special cases. An analogous treatment of statics is also presented. It is established that the formulations presented are capable of generating exact solutions in closed form for several interesting problems in manipulator analysis. Several such results have been obtained via extensive usage of symbolic computation tools developed for this purpose. The proposed approach is applicable to manipulators of different architectures. However, the focus is on the parallel and hybrid manipulators, as their analysis presents more challenges than their serial counterparts. The theory of screws has been adopted as the basis of the formulation. Instantaneous kinematics and statics are studied in terms of the principal bases of the space of twists, se(3), and the space of wrenches, se* (3), respectively. A dual number parameterisation of the motion space is adopted to make the formulation compact and dimensionally consistent. The properties of the dual combination obviate the need for an explicit scaling between the linear and angular velocities or the forces and moments. Hence the results obtained from the formulation are purely geometrical. The analysis of the twists is performed via the dual velocity Jacobian matrix. The principal basis of se(3) is obtained from the eigenproblem of a symmetrical dual matrix associated with the Jacobian. The notion of a dual eigenproblem is introduced in this context. Solutions are provided for the general case, as well as a few special cases. The computations involve the solution of at most a cubic equation for any arbitrary degree-of-freedom of rigid-body motion, and closed form results are therefore ensured. The results of the eigen-analysis lead to a decoupling of the rotational and the pure translational components of a rigid-body motion. This is termed as the partitioning of degrees-of-freedom. They also motivate an interesting classification of the manipulators based on the instantaneous partition of its degrees-of-freedom. This notion is further extended to analyse the effects of a singularity on the motion characteristics of a manipulator. Due to the duality of se(3) and se*(3), the formulation of statics is completely analogous, and involves, in essence, only the substitution of the dual wrench-transformation matrix for the dual Jacobian. A similar partitioning of the wrench system is introduced based on the eigen-decomposition in the context of statics. It is shown that the principal screws associated with either a system of twists or wrenches can be obtained from a generalised eigenproblem of two symmetric real matrices arising out of the symmetric dual matrix mentioned above. The general 2-and 3-screw systems are analysed in closed form via the generalised characteristic polynomial. Several special screw systems are described in terms of algebraic equations in terms of the coefficients of this polynomial. Principal bases for 4-and 5-systems are obtained in a novel fashion without deriving their reciprocal systems explicitly. Using the same approach based on the analysis of the characteristic polynomial, compact algebraic conditions for singularity and isotropy are derived as the special cases of a single formulation. The above formulations establish the existence of exact closed-form results. However, to implement them symbolically for a real application problem, capabilities in existing computer algebra systems do not suffice in general. Therefore simplification and computational algorithms are developed for dealing with large expressions with algebraic and trigonometric terms typically appearing in kinematics and statics. Three canonical forms of such expressions and the corresponding simplification schemes are presented. The theoretical developments are illustrated with examples of serial, parallel and hybrid manipulators throughout the thesis. However, the most important applications of these are in the kinematic and static analysis of a semi-regular Stewart platform manipulator (in which the top and bottom platforms are semi-regular hexagons). Using the degeneracy of the wrench transformation matrix as the singularity criterion, the singularity manifold of the manipulator is obtained via extensive application of the symbolic simplification algorithms. The constant-orientation singularity manifold is derived in a compact closed form, and a complete geometric characterisation and explicit parameterisation of the same are presented. The constant-position singularity manifold is also obtained in closed form. On the other hand, families of configurations of the manipulator for combined kinematic or static isotropy for a given architecture are derived in closed form. Also, architectural designs are obtained for the manipulator such that it exhibits combined kinematic or static isotropy at a given configuration.
215

Religious beliefs and developmental factors in the psychological well-being of differing Christian faith groups : towards a model of psycho-spiritual abuse

Garcia, Daniel, 1977- 23 September 2011 (has links)
The past two decades have seen a surge of research publications in the psychology of religion, with most studies affirming the salutary effects afforded by religious functioning. However, current mental health researchers have advocated for more nuanced examinations of religious constructs and more careful analysis of potentially harmful aspects of religiosity. Particularly absent from the psychological literature are the mental health effects religious beliefs may exert on parishioners. Researchers note that this is surprising given the general psychological tenet that beliefs are inextricably bound-up with affective states and general mental health. Responding to the admonition of researchers in the field, this study proposes and tests an initial model of psycho-spiritual abuse. The proposed model of psycho-spiritual abuse hypothesizes that religious beliefs such as the theological doctrine of original sin, fundamentalist ideology, lack of self-forgiveness, and negative God-representations, in addition to familial upbringing, may negatively impact an individual’s view of self, thus fostering psychological distress. In particular, this study considers scrupulosity disorder, depression, and shame to be the primary psychiatric maladies engendered by psycho-spiritual abuse. Two hundred thirty five parishioners from 18 Christian faith groups across the United States participated in an online survey consisting of standardized measures of original sin, fundamentalism, self-forgiveness, god image, perceived parental rearing, scrupulosity, depression, and shame. A canonical correlation analysis was conducted because it allows for the simultaneously testing of the relationship between the criterion variables (i.e., scrupulosity, depression, and shame) and predictor variables (i.e., original sin, religious fundamentalism, self-forgiveness, parental rearing perceived as rejecting, emotionally warm, and overprotective, as well as accepting, presence, and challenging God-representations) of interest. Results reveal that greater degrees of belief in the theological doctrine of original sin as well as greater adherence to religious fundamentalist ideologies are directly and indirectly associated with scrupulous and depressive symptomatology as well as with shame-prone feelings and actions in unhealthy ways. Results also indicate that God-representations also play an essential role in scrupulosity, depression, and shame in hypothesized ways. Hence, such results further implicate the centrality of religious ideologies in the expression of psychopathology. Additionally, results seem to suggest that the direct familial contribution to the expression of psychopathology among parishioners appears to be weaker (i.e., secondary) than that of religious beliefs; this statement is based on the fact that perceived parental rearing practices were secondary contributors to the synthetic variable of psycho-spiritual beliefs in both Function 1 and 2. Finally, these results suggest that the primary mechanism through which religious beliefs as well as familial upbringing impact parishioner psychological well-being is the resulting view of the self they engender. Therefore, results suggest that the proposed model of psycho-spiritual abuse is sound. / text
216

Klasterinės ir diskriminantinės analizės taikymai mokinių pasiekimų tyrimui / The application of Cluster and Discriminant analysis in students achievements research

Lazdauskaitė, Sandra 16 August 2007 (has links)
Nacionalinių mokinių pasiekimų tyrimo metodologija yra nuolat plėtojama. Pasitarus su Švietimo plėtotės centro tyrimo skyriaus darbuotojais, buvo nuspręsta įsigilinti į klasterinės ir diskriminantinės analizės metodus, jų pritaikomumą nacionalinių tyrimų rezultatų analizei. Tai įtakojo šio darbo pasirinkimą ir tikslą - susipažinti su Klasterinės ir Diskriminantinės analizės metodais, pateikti ir aptarti jų taikymo pavyzdžius. Darbe išnagrinėti du daugiamačiai statistiniai metodai: klasterinė ir diskriminantinė analizė. Yra aptarti šių metodų teoriniai aspektai bei pateikti originalūs šių metodų pritaikymo mokinių pasiekimų tyrimams pavyzdžiai. Padarytos išvados apie šių metodų pritaikomumą nacionalinių mokinių pasiekimų tyrimo analizei atlikti. / National research of student marches are continually evolving. With Educational evolve center’s help I decided to analyse Cluster and Disckriminant analysis methods and how they can be used in National research analysis. This was a reason of my work purpose - to have a look at Cluster and Disckriminant analysis methods, to offer examples of practical use. There are two statistical multidimensional methods discussed in this work (Cluster and Disckriminant analysis). There are discussed theoretical side of these methods, also you can find original examples of practical use. In conclusion I discuss about practical use of these methods in national research of student marches.
217

Diferencialinio uždavinio su kintamais koeficientais tyrimas / Investigation of differential problem with variable coefficients

Rapalytė, Svajūnė 20 June 2012 (has links)
Magistro baigiamajame darbe nagrinėjamas diferencialinis operatorius su kintamais koeficientais ir viena klasikine, o kita nelokaliąja Samarskio ir Bitsadzės kraštine sąlyga. Šis uždavinys suvedamas į kanoninį pavidalą. Tiriamos kintamo koeficiento savybės, kaip jos keičiasi suvedant uždavinį į kanoninį pavidalą, taip pat tiriama šio uždavinio spektro priklausomybė nuo nelokaliosios kraštinės sąlygos parametrų. / In the Master's Thesis there is investigated a differential operator with variable coefficients, one classical and other nonlocal Samarskii-Bitsadze type boundary condition. There is written the canonical form of this problem. In the thesis there is analyzed the properties of variable coefficients, how they are changing when differential problem is written in the canonical form. Also the dependence of this problem spectrum on nonlocal boundary condition parameters is investigated.
218

The Black-Litterman Asset Allocation Model : An Empirical Comparison to the Classical Mean-Variance Framework

Hirani, Shyam, Wallström, Jonas January 2014 (has links)
Within the scope of this thesis, the Black-Litterman Asset Allocation Model (as presented in He & Litterman, 1999) is compared to the classical mean-variance framework by simulating past performance of portfolios constructed by both models using identical input data. A quantitative investment strategy which favours stocks with high dividend yield rates is used to generate private views about the expected excess returns for a fraction of the stocks included in the sample. By comparing the ex-post risk-return characteristics of the portfolios and performing ample sensitivity analysis with respect to the numerical values assigned to the input variables, we evaluate the two models’ suitability for different categories of portfolio managers. As a neutral benchmark towards which both portfolios can be measured, a third market-capitalization-weighted portfolio is constructed from the same investment universe. The empirical data used for the purpose of our simulations consists of total return indices for 23 of the 30 stocks included in the OMXS30 index as of the 21st of February 2014 and stretches between January of 2003 and December of 2013.   The results of our simulations show that the Black-Litterman portfolio has delivered risk-adjusted return which is superior not only to that of its market-capitalization-weighted counterpart but also to that of the classical mean-variance portfolio. This result holds true for four out of five simulated strengths of the investment strategy under the assumption of zero transaction costs, a rebalancing frequency of 20 trading days, an estimated risk aversion parameter of 2.5 and a five per cent uncertainty associated with the CAPM prior. Sensitivity analysis performed by examining how the results are affected by variations in these input variables has also shown notable differences in the sensitivity of the results obtained from the two models. While the performance of the Black-Litterman portfolio does undergo material changes as the inputs are varied, these changes are nowhere near as profound as those exhibited by the classical mean-variance portfolio.   In the light of our empirical results, we also conclude that there are mainly two aspects which the portfolio manager ought to consider before committing to one model rather than the other. Firstly, the nature behind the views generated by the investment strategy needs to be taken into account. For the implementation of views which are of an α-driven character, the dynamics of the Black-Litterman model may not be as appropriate as for views which are believed to also influence the expected return on other securities. Secondly, the soundness of using market-capitalization weights as a benchmark towards which the final solution will gravitate needs to be assessed. Managers who strive to achieve performance which is fundamentally uncorrelated to that of the market index may want to either reconsider the benchmark weights or opt for an alternative model.
219

Towards large-scale quantum computation

Fowler, Austin Greig Unknown Date (has links) (PDF)
This thesis deals with a series of quantum computer implementation issues from the Kane 31P in 28Si architecture to Shor’s integer factoring algorithm and beyond. The discussion begins with simulations of the adiabatic Kane CNOT and readout gates, followed by linear nearest neighbor implementations of 5-qubit quantum error correction with and without fast measurement. A linear nearest neighbor circuit implementing Shor’s algorithm is presented, then modified to remove the need for exponentially small rotation gates. Finally, a method of constructing optimal approximations of arbitrary single-qubit fault-tolerant gates is described and applied to the specific case of the remaining rotation gates required by Shor’s algorithm.
220

Relações entre as variáveis edáficas e vegetacionais em cerrado hiperestacional, cerrado estacional e campo úmido no Parque Nacional das Emas (GO).

Amorim, Priscilla Kobayashi 23 September 2005 (has links)
Made available in DSpace on 2016-06-02T19:32:16Z (GMT). No. of bitstreams: 1 DissPKA.pdf: 490127 bytes, checksum: 18f6cf8d6514765ac9c01c7df71da800 (MD5) Previous issue date: 2005-09-23 / Universidade Federal de Minas Gerais / The Cerrado Domain occupied formerly 2 million km2 of the Brazilian territory, especially in the Central Plateau. The cerrado vegetation is not uniform in physiognomy, ranging from grassland to tall woodland, but with most of its physiognomies within the range defined as tropical savanna. In cerrado, there are few areas that become waterlogged during the rainy season due to the poor drainage of the soil, allowing the appearance of a hyperseasonal cerrado, characterized by two contrasting stresses, one induced by drought and fire during the winter, the other by soil saturation in the summer. As long as soil is important in the ecology of the cerrado, limiting the cerrado distribution and the occurrence of its physiognomies, we investigated the soil-vegetation relationships in a cerrado core area in Emas National Park, in three vegetation forms: hyperseasonal cerrado, seasonal cerrado, and wet grassland. We collected vegetation and soil samples in these three vegetation forms and submitted obtained data to a canonical correspondence analysis. Our results showed a distinction among hyperseasonal cerrado, seasonal cerrado and wet grassland, which presented different floristic compositions and species abundances. The edaphic variables best related to the hyperseasonal and seasonal cerrados were sand, base saturation, pH, and magnesium. The wet grassland was related to higher concentrations of clay, organic matter, aluminium saturation, aluminium, phosphorus, and potassium. We also investigated the relationships between number of species and soil characteristics, with simple multiple linear regressions, and found that aluminium and pH were the best predictors of species density, the former positively related to species density and the latter negatively related. / O Domínio do Cerrado ocupava aproximadamente dois milhões de km2 do território brasileiro, especialmente no Planalto Central. A vegetação de cerrado não é uniforme em sua fisionomia, pois varia desde o campo limpo até o cerradão, mas a maior parte de suas fisionomias podem ser definidas como savana. Em algumas raras áreas de cerrado, a drenagem do solo é muito baixa, provocando o seu alagamento na estação chuvosa e favorecendo o surgimento de cerrados hiperestacionais, em que há dois períodos de estresse, um induzido pela seca e pelo fogo no inverno, e outro induzido pelo alagamento no verão. Como o solo é um dos principais fatores que controlam a distribuição do cerrado, além de ser determinante para a ocorrência das diferentes fisionomias que o compõem, nosso objetivo neste trabalho foi estudar a relação solo-vegetação em uma área nuclear de cerrado, no Parque Nacional das Emas (GO), em três ambientes: cerrado hiperestacional, cerrado estacional e campo úmido. Amostramos o solo e a vegetação desses três ambientes e comparamos algumas variáveis edáficas e vegetacionais por meio de análise de correspondência canônica. Nossos resultados apresentaram uma distinção florística entre o cerrado hiperestacional, o cerrado estacional e o campo úmido. As variáveis edáficas mais relacionadas com os cerrados hiperestacional e estacional foram porcentagem de areia, saturação por bases, pH e magnésio, enquanto que com o campo úmido foram argila, matéria orgânica, alumínio, saturação por alumínio e potássio. Também relacionamos o número de espécies em cada parcela com algumas variáveis edáficas, por meio de análises de regressão, e encontramos que o pH foi relacionado negativamente, e o alumínio, positivamente, com o número de espécies.

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