Doctor of Philosophy

dissertationMyocardial microstructure plays an important role in sustaining the orchestrated beating motion of the heart. Several microstructural components, including myocytes and auxiliary cells, extracellular space, and blood vessels provide the infrastructure for normal heart function, including excitation propagation, myocyte contraction, delivery of oxygen and nutrients, and removing byproduct wastes. Cardiac diseases cause deleterious changes to some or all of these microstructural components in the detrimental process of cardiac remodeling. Since heart failure is among the leading causes of death in the world, new and novel tools to noninvasively characterize heart microstructure are needed for monitoring and staging of cardiac disease. In this regards, diffusion magnetic resonance imaging (MRI) provides a promising framework to probe and quantify tissue microstructure without the need for exogenous contrast agent. As diffusion in 3-dimensional space is characterized by the diffusion tensor, MR diffusion tensor imaging (DTI) is being used to noninvasively measure anisotropic diffusion, and thus the magnitude and spatial orientation of microstructural organization of tissues, including the heart. However, even though in vivo cardiac DTI has become more clinically available, to date the origin and behavior of different microstructural components on the measured DTI signal remain to be explicitly specified. The presented studies in this work demonstrate that DTI can be used as a noninvasive and contrast-free imaging modality to characterize myocyte size and density, extracellular collagen content, and the directional magnitude of blood flow. The identified applications are expected to provide metrics to enable physicians to detect, quantify, and stage different microstructural components during progression of cardiac disease

Improved decoder metrics for DS-CDMA in practical 3G systems

While 4G mobile networks have been deployed since 2008. In several of the more developed markets, 3G mobile networks are still growing with 3G having the largest market -in terms of number of users- by 2019. 3G networks are based on Direct- Sequence Code-Division Multiple-Access (DS-CDMA). DS-CDMA suffers mainly from the Multiple Access Interference (MAI) and fading. Multi-User Detectors (MUDs) and Error Correcting Codes (ECCs) are the primary means to combat MAI and fading. MUDs, however, suffer from high complexity, including most of sub-optimal algorithms. Hence, most commercial implementations still use conventional single-user matched filter detectors. This thesis proposes improved channel decoder metrics for enhancing uplink performance in 3G systems. The basic idea is to model the MAI as conditionally Gaussian, instead of Gaussian, conditioned on the users’ cross-correlations and/or the channel fading coefficients. The conditioning implies a time-dependent variance that provides enhanced reliability estimates at the decoder inputs. We derive improved log-likelihood ratios (ILLRs) for bit- and chip- asynchronous multipath fading channels. We show that while utilizing knowledge of all users’ code sequences for the ILLR metric is very complicated in chip-asynchronous reception, a simplified expression relying on truncated group delay results in negligible performance loss. We also derive an expression for the error probability using the standard Gaussian approximation for asynchronous channels for the widely used raised cosine pule shaping. Our study framework considers practical 3G systems, with finite interleaving, correlated multipath fading channel models, practical pulse shaping, and system parameters obtained from CDMA2000 standard. Our results show that for the fully practical cellular uplink channel, the performance advantage due to ILLRs is significant and approaches 3 dB

Management of business functions of small and medium enterprises and the influence of management models in their development

Mala i srednja preduzeća imaju značajno mesto u razvijenim ekonomijama. Ovaj oblik organizacije omogućava visoku fleksibilnost poslovanja, lakšu adaptaciju u slučaju cikličnih ekonomskih kretanja, ali i uspešniji prolazak kroz krizne periode. Takođe, prednjače u poslovnoj inicijativi, inovacijama i u njima se zapošljava veliki deo radno sposobnog stanovništva. Predmet istraživanja je sagledavanje uticaja modela menadžmenta 3 na razvoj malih i srednjih preduzeća, kroz upravljanje njihovim poslovnim funkcijama. Mala i srednja preduzeća pružaju najveći doprinos zaposlenosti i ekonomskom rastu i razvoju u svetu, a poslednje decenije njihovog rasta i razvoja, označile su nastanak novih promena, koje se mogu označiti kao revolucionarne. U cilju njihovog uključivanja u nove tokove, nameće se potreba istraživanja novih načina, odnosno modela povezivanja, koji podrazumeva zajednički interes i nastup na internacionalnom tržištu. Osnovni cilj istraživanja je izbor najpovoljnijih modela menadžmenta i njihov uticaj u procesu razvoja malih i srednjih preduzeća i upravljanja poslovnim funkcijama preduzeća.Small and medium enterprises have a significant place in developed economies. This form of organization enables high business flexibility, easier adaptation in case of cyclical economic trends, but also more successful passage through crisis periods. Also, they are the leaders in business initiative, innovations and they employ a large part of the working age population. The subject of the research is to consider the impact of the management model on the development of small and medium 5 enterprises, through the management of their business functions. Small and medium enterprises make the greatest contribution to employment and economic growth and development in the world, and the last decades of their growth and development have marked the emergence of new changes, which can be described as revolutionary. In order to include them in new trends, there is a need to explore new ways, ie models of connection, which implies a common interest and appearance on the international market. The main goal of the research is the selection of the most favorable management models and their impact in the process of development of small and medium enterprises and management of business functions of enterprises

Improving Statistical Learning within Functional Genomic Experiments by means of Feature Selection

A Statistical learning approach concerns with understanding and modelling complex datasets. Based on a given training data, its main aim is to build a model that maps the relationship between a set of input features and a considered response in a predictive way. Classification is the foremost task of such a learning process. It has applications encompassing many important fields in modern biology, including microarray data as well as other functional genomic experiments. Microarray technology allow measuring tens of thousands of genes (features) simultaneously. However, the expressions of these genes are usually observed in a small number, tens to few hundreds, of tissue samples (observations). This common characteristic of high dimensionality has a great impact on the learning processes, since most of genes are noisy, redundant or non-relevant to the considered learning task. Both the prediction accuracy and interpretability of a constructed model are believed to be enhanced by performing the learning process based only on selected informative features. Motivated by this notion, a novel statistical method, named Proportional Overlapping Scores (POS), is proposed for selecting features based on overlapping analysis of gene expression data across different classes of a considered classification task. This method results in a measure, called POS score, of a feature’s relevance to the learning task. POS is further extended to minimize the redundancy among the selected features. The proposed approaches are validated on several publicly available gene expression datasets using widely used classifiers to observe effects on their prediction accuracy. Selection stability is also examined to address the captured biological knowledge in the obtained results. The experimental results of classification error rates computed using the Random Forest, k NearestNeighbor and Support VectorMachine classifiers show that the proposals achieve a better performance than widely used gene selection methods

Management of business functions of small and medium enterprises and the influence of management models in their development

Mala i srednja preduzeća imaju značajno mesto u razvijenim ekonomijama. Ovaj oblik organizacije omogućava visoku fleksibilnost poslovanja, lakšu adaptaciju u slučaju cikličnih ekonomskih kretanja, ali i uspešniji prolazak kroz krizne periode. Takođe, prednjače u poslovnoj inicijativi, inovacijama i u njima se zapošljava veliki deo radno sposobnog stanovništva. Predmet istraživanja je sagledavanje uticaja modela menadžmenta 3 na razvoj malih i srednjih preduzeća, kroz upravljanje njihovim poslovnim funkcijama. Mala i srednja preduzeća pružaju najveći doprinos zaposlenosti i ekonomskom rastu i razvoju u svetu, a poslednje decenije njihovog rasta i razvoja, označile su nastanak novih promena, koje se mogu označiti kao revolucionarne. U cilju njihovog uključivanja u nove tokove, nameće se potreba istraživanja novih načina, odnosno modela povezivanja, koji podrazumeva zajednički interes i nastup na internacionalnom tržištu. Osnovni cilj istraživanja je izbor najpovoljnijih modela menadžmenta i njihov uticaj u procesu razvoja malih i srednjih preduzeća i upravljanja poslovnim funkcijama preduzeća.Small and medium enterprises have a significant place in developed economies. This form of organization enables high business flexibility, easier adaptation in case of cyclical economic trends, but also more successful passage through crisis periods. Also, they are the leaders in business initiative, innovations and they employ a large part of the working age population. The subject of the research is to consider the impact of the management model on the development of small and medium 5 enterprises, through the management of their business functions. Small and medium enterprises make the greatest contribution to employment and economic growth and development in the world, and the last decades of their growth and development have marked the emergence of new changes, which can be described as revolutionary. In order to include them in new trends, there is a need to explore new ways, ie models of connection, which implies a common interest and appearance on the international market. The main goal of the research is the selection of the most favorable management models and their impact in the process of development of small and medium enterprises and management of business functions of enterprises

Accounting Education and Accountancy Profession in Jordan: The Current Status and the Processes of Improvement

The main aims in the current research paper are to identify the problems that are obstructing the development of accounting education and the accounting profession in Jordan and to identify strategies and techniques that can be effective in improving accounting education and the accounting profession in Jordan.  The accounting educational system in Jordanian universities should emphasize on how to better serve students and ensure that they will be competitive in the future work force. Accounting education should seek to adapt to the trend of professional accounting development. A questionnaire had been designed and distributed to (73) accounting instructors in Jordan. The population of this study consists of all accounting instructors employed in the both public and private Universities in Jordan. 73 questionnaires were distributed and 56 were returned giving a response rate of 77%. The results of this study revealed that the important factors for the improvement of accounting education and the accounting profession in Jordan include inadequate use of computers applications in accounting during teaching process and inadequate salaries of accounting instructors. Poor university infrastructure resulting in the creation of ineffective class groups. Similarly, this research tested a list of strategies and techniques that have been recommended for the improvement of accounting education and the accounting profession in developing countries. The research discovered that many of the strategies could be effective in improving accounting education and the accounting profession in Jordan. However, there are other strategies that would not be effective. Some of these include the development of accounting textbooks in domestic languages, setting local auditing and accounting standards and, localising professional accounting examinations. In this research paper, attempts were made to identify problems that are hindering the enhancement of accounting education and the accounting profession in Jordan. An analysis of strategies that can be employed to improve accounting education and the accounting profession in Jordan was also carried out, with a view to determine those strategies that can provide effective accounting education in specific developing country. Keywords: Accounting Education, Accounting Profession, Jorda