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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.
31

Enhancing the performance of decoupled software pipeline through backward slicing

Alwan, Esraa January 2014 (has links)
The rapidly increasing number of cores available in multicore processors does not necessarily lead directly to a commensurate increase in performance: programs written in conventional languages, such as C, need careful restructuring, preferably automatically, before the benefits can be observed in improved run-times. Even then, much depends upon the intrinsic capacity of the original program for concurrent execution. Using software techniques to parallelize the sequential application can raise the level of gain from multicore systems. Parallel programming is not an easy job for the user, who has to deal with many issues such as dependencies, synchronization, load balancing, and race conditions. For this reason the role of automatically parallelizing compilers and techniques for the extraction of several threads from single-threaded programs, without programmer intervention, is becoming more important and may help to deliver better utilization of modern hardware. One parallelizing technique that has been shown to be an effective for the parallelization of applications that have irregular control flow and complex memory access patterns is Decoupled Software Pipeline (DSWP). This transformation partitions the loop body into a set of stages, ensuring that critical path dependencies are kept local to a stage. Each stage becomes a thread and data is passed between threads using inter-core communication. The success of DSWP depends on being able to extract the relatively fine-grain parallelism that is present in many applications. Another technique which offers potential gains in parallelizing general purpose applications is slicing. Program slicing transforms large programs into several smaller ones that execute independently, each consisting of only statements relevant to the computation of certain, socalled, (program) points. This dissertation explores the possibility of performance benefits arising from a secondary transformation of DSWP stages by slicing. To that end a new combination method called DSWP/Slice is presented. Our observation is that individual DSWP stages can be parallelized by slicing, leading to an improvement in performance of the longest duration DSWP stages. In particular, this approach can be applicable in cases where DOALL is not. In consequence better load balancing can be achieved between the DSWP stages. Moreover, we introduce an automatic implementation of the combination method using Low Level Virtual Machine (LLVM) compiler framework. This combination is particularly effective when the whole long stage comprises a function body. More than one slice extracted from a function body can speed up its execution time and also increases the scalability of DSWP. An evaluation of this technique on six programs with a range of dependence patterns leads to considerable performance gains on a core-i7 870 machine with 4-cores/8-threads. The results are obtained from an automatic implementation that shows the proposed method can give a factor of up to 1.8 speed up compared with the original sequential code.
32

Sequence Diagram Slicing

Noda, Kunihiro, Kobayashi, Takashi, Agusa, Kiyoshi, Yamamoto, Shinichiro 01 December 2009 (has links)
No description available.
33

Samspelet mellan finansiella rådgivare och kunder

Hansson, Sofia, Lövquist, Joanna January 2011 (has links)
Background: Previous studies focused on customer loyalty and customer satisfaction. But no studies focused on the interaction between the financial advisor and their client. Therefore we have chosen to focus on this knowledge gap.Purpose: The purpose of this thesis is to illustrate how the interaction between financial advisors and customers affect financial advisory in investment decision making.Method: The thesis philosophy was positivistic because patterns were found with help of a survey. Furthermore is the paper quantitative since the thesis is measurable and it try to explain the interaction between the financial advisors and the clients demographic characteristics and how it influence the financial advice Conclusion: The theories thin-slicing and similarity attraction paradigm may not apply to the interaction between financial advisor and client. / Bakgrund:  Tidigare studier fokuserar på kundnöjdhet och kundlojalitet. Däremot saknas studier kring samspelet mellan finansiell rådgivare och kund. Därför har vi valt att fokusera på denna kunskapslucka Syfte: Syftet med uppsatsen är att belysa hur samspelet mellan finansiella rådgivare och kunder påverkar den finansiella rådgivningen vid ett investeringsbeslut. Metod: Uppsatsen har positivistisk undersökningsfilosofi då mönster hittades med hjälp av en undersökning. Vidare är uppsatsen kvantitativ eftersom den är mätbar och att den har undersökt om det finns några samband mellan den finansiella rådgivarens och kundens demografiska egenskaper samt om dessa påverkar rådgivningen. Slutsats: Teorierna thin-slicing och similarity attraction paradigm kan inte tillämpas i samspelet mellan finansiella rådgivare och kunder.
34

Assembly Instruction Level Reverse Execution for Debugging

Akgul, Tankut 12 April 2004 (has links)
Reverse execution can be defined as a method which recovers the states that a program attains during its execution. Therefore, reverse execution eliminates the need for repetitive program restarts every time a bug location is missed. This potentially shortens debug time considerably. This thesis presents a new approach which, for the first time ever (to the best of the author's knowledge), achieves reverse execution at the assembly instruction level on general purpose processors via execution of a reverse program. A reverse program almost always regenerates destroyed states rather than restoring them from a record. Furthermore, a reverse program provides assembly instruction by assembly instruction execution in the backward direction. This significantly reduces state saving and thus decreases the associated memory and time costs of reverse execution support. Furthermore, this thesis presents a new dynamic slicing algorithm that is built on top of assembly instruction level reverse execution. Dynamic slicing is a technique which isolates the code parts that influence an erroneous variable at a program point. The algorithm presented in this thesis achieves dynamic slicing via execution of a reduced reverse program. A reduced reverse program is obtained from a full reverse program by omitting the instructions that recover states irrelevant to the dynamic slice under consideration. This provides a reverse execution capability along a designated dynamic slice only. The use of a reduced reverse program for dynamic slicing removes the need for runtime execution trajectories. The methodology of this thesis has been implemented on a PowerPC processor with a custom made debugger. As compared to previous work, all of which heavily use state saving techniques, the experimental results show up to 2206X reduction in runtime memory usage, up to 403X reduction in forward execution time overhead and up to 2.32X reduction in forward execution time for the tested benchmarks. Measurements on the selected benchmarks also indicate that the dynamic slicing method presented in this thesis can achieve up to six orders of magnitude (1,928,500X) speedups in reverse execution along the dynamic slice as compared to full-scale reverse execution.
35

Automatic Generation of Simulation Models from Designs

Axling, Erik January 2007 (has links)
<p>When working with embedded systems, secure and fast applications are desired. To achieve this the applications needs to be analyzed and optimized so that they will not be deadlocked or communicate inefficiently. For this purpose an analysis program that can track communications, deadlocks and response times is needed. Operating System Embedded, OSE, is a wide spread real-time operating system that is used in embedded systems. OSE-applications are excellent candidates for analysis and there exists such a tool, VirtualTime, for that purpose. To analyze an OSE-application a model needs to be written that VirtualTime can analyze. This takes up time and effort as the models can require a lot of work to write.</p><p>In this thesis we have investigated and implemented a prototype that translates OSE-application code into VirtualTime simulation model code. We used the transformation tool TXL to translate communication and timing behaviors. In the translation one needs to preserve the communication and timing behavior and throw away other unnecessary code in the OSE-application. This complicates the translation and sophisticated methods like backward slicing might be necessary. A proposed method in this thesis could help with the problem.</p>
36

An adaptable storage slicing algorithm for content delivery networks

MOREIRA, André Luis Cavalcanti 28 August 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-12T12:20:38Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Thesis - André Luis Cavalcanti Moreira.pdf: 3666881 bytes, checksum: 956e0e6be2bd9f076c0d30eea9d3ea25 (MD5) / Made available in DSpace on 2016-07-12T12:20:38Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Thesis - André Luis Cavalcanti Moreira.pdf: 3666881 bytes, checksum: 956e0e6be2bd9f076c0d30eea9d3ea25 (MD5) Previous issue date: 2015-08-28 / Several works study the performance of Content Delivery Networks (CDNs) under various network infrastructure and demand conditions. Many strategies have been proposed to deal with aspects inherent to the CDN distribution model. Though mostly very effective, a traditional CDN approach of statically positioned elements often fails to meet quality of experience (QoE) requirements when network conditions suddenly change. CDN adaptation is a key feature in this process and some studies go even further and try to also deal with demand elasticity by providing an elastic infrastructure (cloud computing) to such CDNs. Each Content Provider (CP) gets served only the amount of storage space and network throughput that it needs and pays only for what has been used. Some IaaS providers offer simple CDN services on top of their infrastructure. However, in general, there is a lack of PaaS tools to create rapidly a CDN. There is no standard or open source software able to deliver CDN as a service for each tenant through well-known managers. A PaaS CDN should be able to implement content delivery service in a cloud environment, provision and orchestrate each tenant, monitor usage and make decisions on planning and dimensioning of resources. This work introduces a framework for the allocation of resources of a CDN in a multi-tenant environment. The framework is able to provision and orchestrate multi-tenant virtual CDNs and can be seen as a step towards a PaaS CDN. A simple dot product based module for network change detection is presented and a more elaborate multi-tenant resource manager model is defined. We solve the resulting ILP problem using both branch and bound as well as an efficient cache slicing algorithm that employs a three phase heuristic for orchestration of multi-tenant virtual CDNs. We finally show that a distributed algorithm with limited local information may be also offer reasonable resource allocation while using limited coordination among the different nodes. A self-organization behavior emerges when some of the nodes reach consensus. / Vários trabalhos estudam o desempenho de Redes de Distribuição de Conteúdo (CDN) em diferentes condições e demanda e de infraestrutura. Muitas estratégias têm sido propostas para lidar com aspectos inerentes ao modelo de distribuição de CDN. Embora essas técnicas sejam bastante eficazes, uma abordagem tradicional de elementos estaticamente posicionados numa CDN muitas vezes não consegue atender os requisitos de qualidade de experiência (QoE) quando as condições da rede mudam repentinamente. Adaptação CDN é uma característica fundamental neste processo e alguns estudos vão ainda mais longe e tentam lidar com a elasticidade da demanda, proporcionando uma infraestrutura elástica (computação em nuvem) para a CDN. Cada provedor de conteúdo obtém apenas a quantidade de armazenamento e de rede necessários, pagando apenas pelo efetivo uso. Alguns provedores IaaS oferecem serviços de CDN sobre suas estruturas. No entanto, em geral, não existe padrão ou softwares de código aberto capazes de entregar serviços de CDN por meio de gerenciadores. Uma CDN PaaS deve ser capaz de fornecer um serviço de entrega de conteúdo em um ambiente de nuvem, provisionar e orquestrar cada tenant, monitorar uso e tomar decisões de planejamento e dimensionamento de recursos. Este trabalho apresenta um framework para alocação de recursos de uma CDN em ambiente multi-tenant. O framework é capaz de provisionar e orquestrar CDNs virtuais e pode ser visto como um passo em direção a uma PaaS CDN. Um módulo baseado em simples produto escalar para detecção de mudanças na rede é apresentado, bem como um modelo mais elaborado de gerenciamento de recursos. Resolvemos o problema ILP resultante dessa abordagem por meio de um algoritmo de divisão de cache que emprega uma heurística em três fases para a orquestração de CDN virtuais. Por fim, mostramos uma outra abordagem com algoritmo distribuído que usa informação local e que também oferece uma alocação razoável usando coordenação limitada entre os diferentes nós. Um comportamento de auto-organização surge quando alguns desses nós chegam a um consenso.
37

Automatic Generation of Simulation Models from Designs

Axling, Erik January 2007 (has links)
When working with embedded systems, secure and fast applications are desired. To achieve this the applications needs to be analyzed and optimized so that they will not be deadlocked or communicate inefficiently. For this purpose an analysis program that can track communications, deadlocks and response times is needed. Operating System Embedded, OSE, is a wide spread real-time operating system that is used in embedded systems. OSE-applications are excellent candidates for analysis and there exists such a tool, VirtualTime, for that purpose. To analyze an OSE-application a model needs to be written that VirtualTime can analyze. This takes up time and effort as the models can require a lot of work to write. In this thesis we have investigated and implemented a prototype that translates OSE-application code into VirtualTime simulation model code. We used the transformation tool TXL to translate communication and timing behaviors. In the translation one needs to preserve the communication and timing behavior and throw away other unnecessary code in the OSE-application. This complicates the translation and sophisticated methods like backward slicing might be necessary. A proposed method in this thesis could help with the problem.
38

Scalable and accurate approaches for program dependence analysis, slicing, and verification of concurrent object oriented programs

Ranganath, Venkatesh Prasad January 1900 (has links)
Doctor of Philosophy / Department of Computing and Information Science / John M. Hatcliff / With the advent of multi-core processors and rich language support for concurrency, the paradigm of concurrent programming has arrived; however, the cost of developing and maintaining concurrent programs is still high. Simultaneously, the increase in social ubiquity of computing is reducing the "time-to-market" factor while demanding stronger correctness requirements. These effects are amplified with ever-growing size of software systems. Consequently, there is (will be) a rise in the demand for scalable and accurate techniques to enable faster development and maintenance of correct large scale concurrent software. This dissertation presents a collection of scalable and accurate approaches to tackle the above situation. Primarily, the approaches are focused on discovering dependences (relations) between various parts of the software/program and leveraging the dependences to improve maintenance and development tasks via program slicing (comprehension) and verification. Briefly, the proposed approaches are embodied in the following specific contributions: 1. New trace-based foundation for control dependences. 2. An equivalence class based analysis to efficiently and accurately calculate escape information and intra- and inter-thread dependences. 3. A new parametric data flow style slicing algorithm with various extensions to uniformly and easily realize and reason about most existing forms of static sequential and concurrent slicing. 4. A new generic notion of property/trace sensitivity to represent and reason about richer forms of context sensitivity. 5. Program dependence based partial order reduction techniques to enable efficient and accurate state space exploration in both static and dynamic mode. In an attempt to simplify the approaches, they have been based on the basic concepts/ideas of the affected techniques (e.g. program slicing is a rooted transitive closure of dependence relation). As trace-based reasoning is well suited for concurrent systems, an attempt has been made to explore trace-based reasoning wherever possible. While providing a rigorous theoretical presentation of these techniques, this effort also validates the techniques by implementing them in a robust tool framework called Indus (available from http://indus.projects.cis.ksu.edu) and then providing experimental results that demonstrate the effectiveness of the techniques on various concurrent applications. Given the current trend towards concurrent programming and social ubiquity of computing, the approaches proposed in this dissertation provide a foundation for collectively attacking scalability, accuracy, and soundness challenges in current and emerging systems.
39

Improvement of cattle oocyte retrieval techniques and hormonal influence on in vitro embryonic development

Lekola, Khomotso Podile Molvia January 2015 (has links)
Thesis (M. Sc. (Animal Production)) -- University of Limpopo / The objectives of this study were: 1) To determine the effect of oocyte retrieval techniques (slicing and aspiration) on the quality and quantity of cattle oocytes, 2) To evaluate the effect of different concentrations of hormones on the maturational rate of cattle oocytes selected by brilliant cresyl blue staining, 3) To evaluate fertilization rate and cleavage/embryonic development of oocytes with or without cumulus cells, and 4) To compare the effect of fresh and frozen thawed semen on the fertilization rate of cattle oocytes. In Experiment 1: oocytes were recovered from abattoir derived ovaries using slicing and aspiration. The recovered oocytes were exposed for 90 minutes to 26μM of brilliant cresyl blue (BCB) stain and classified according to the colour of their cytoplasm: BCB+ (oocytes with blue cytoplasm) and BCB- (unstained oocytes). There was no difference (P>0.05) in the quality of oocytes recovered using slicing (60.7 %) or aspiration (53.7 %) techniques. In experiment 2: The BCB selected and the non-selected immature oocytes were randomly allocated into medium 199 + 10 % fetal bovine serum (FBS) maturation media. The media was supplemented with three different concentrations of hormones as treatments (T). The T1 (0.5 μg/ml of follicle stimulating hormone (FSH), 5mg/ml of luteinizing hormone (LH) and 2 μg/ml of estradiol (E2) as the control group. Then, T2 (1 μg/ml of FSH, 6 mg/ml of LH and 2.5 μg/ml of E2) and T3 (1.5 μg/ml of FSH, 7 mg/ml of LH and 4.5 μg/ml of E2). Maturation rate of oocytes was determined by the protrusion of the first polar bodies 24 hours following in vitro maturation. Treatment 2 yielded higher (P<0.05) maturation rate for both BCB+ (65.6 %) and without BCB (60.3 %) oocytes with T1 giving lower (P<0.05) maturation rate for BCB+ (22 %) and without BCB (16 %) oocytes. However, BCB- oocytes had lower (P<0.05) polar body extrusion (3.03 %, 8.1 % and 2.2 %) for T1, T2 and T3, respectively. In Experiment 3: one group of the presumptive zygotes was denuded of cumulus cells and the other group was cultured with cumulus cells. The presumptive zygotes were in vitro cultured in SOF-BSA and changed to SOF-FBS after 48 hours. High fertilization/cleavage rate was observed in oocytes cultured with cumulus cells (29.0 %) compared to the denuded oocytes (20.0 %) for 2-4 cells stage. Day 7 blastocysts were more (P<0.05) on oocytes cultured with cumulus cells (32 %) compared to denuded oocytes (13 %). In experiment 4: The matured oocytes were fertilized using fresh and frozen thawed semen. The oocytes fertilized with frozen thawed semen obtained a better number of 2-4 cell cleavage (23 %) when compared to fresh semen (19 %). Oocytes that were fertilized with frozen thawed semen also obtained higher morula (13 %) and blastocyst (8 %) compared to fresh semen with morula (3.4 %) and blastocyst (2 %). In conclusion, immature oocytes that were exposed to BCB+ and cultured in M199 supplemented with 10 % FBS, 0.5 μg/ml of FSH, 5 mg/ml of LH and 2 μg/ml of E2 had a higher (P<0.05) number of matured oocytes (extrusion of first polar body) compared to those that were not exposed to BCB (no BCB). Oocytes that were cultured with cumulus cells yielded a higher (P<0.05) number of cleaved embryos compared to the denuded oocytes. Slicing yielded a higher (P<0.05) number of oocytes, however the quality of oocytes recovered was similar compared to those recovered by the aspiration technique (P>0.05). Oocytes fertilized with frozen thawed semen yielded higher (P<0.05) number of 2-4 cell, morula and blastocyst when compared with oocytes that were fertilized using fresh semen. Keywords: ovaries, oocytes, slicing, aspiration, COCs, BCB, polar body and cattle
40

Improvement of cattle oocyte retrieval techniques and hormonal influence on in vitro embryonic development

Lekola, Khomotso Podile Molvia January 2015 (has links)
Thesis (M. Sc. (Animal Production)) -- University of Limpopo, 2015 / The objectives of this study were: 1) To determine the effect of oocyte retrieval techniques (slicing and aspiration) on the quality and quantity of cattle oocytes, 2) To evaluate the effect of different concentrations of hormones on the maturational rate of cattle oocytes selected by brilliant cresyl blue staining, 3) To evaluate fertilization rate and cleavage/embryonic development of oocytes with or without cumulus cells, and 4) To compare the effect of fresh and frozen thawed semen on the fertilization rate of cattle oocytes. In Experiment 1: oocytes were recovered from abattoir derived ovaries using slicing and aspiration. The recovered oocytes were exposed for 90 minutes to 26μM of brilliant cresyl blue (BCB) stain and classified according to the colour of their cytoplasm: BCB+ (oocytes with blue cytoplasm) and BCB- (unstained oocytes). There was no difference (P>0.05) in the quality of oocytes recovered using slicing (60.7 %) or aspiration (53.7 %) techniques. In experiment 2: The BCB selected and the non-selected immature oocytes were randomly allocated into medium 199 + 10 % fetal bovine serum (FBS) maturation media. The media was supplemented with three different concentrations of hormones as treatments (T). The T1 (0.5 μg/ml of follicle stimulating hormone (FSH), 5mg/ml of luteinizing hormone (LH) and 2 μg/ml of estradiol (E2) as the control group. Then, T2 (1 μg/ml of FSH, 6 mg/ml of LH and 2.5 μg/ml of E2) and T3 (1.5 μg/ml of FSH, 7 mg/ml of LH and 4.5 μg/ml of E2). Maturation rate of oocytes was determined by the protrusion of the first polar bodies 24 hours following in vitro maturation. Treatment 2 yielded higher (P<0.05) maturation rate for both BCB+ (65.6 %) and without BCB (60.3 %) oocytes with T1 giving lower (P<0.05) maturation rate for BCB+ (22 %) and without BCB (16 %) oocytes. However, BCB- oocytes had lower (P<0.05) polar body extrusion (3.03 %, 8.1 % and 2.2 %) for T1, T2 and T3, respectively. In Experiment 3: one group of the presumptive zygotes was denuded of cumulus cells and the other group was cultured with cumulus cells. The presumptive zygotes were in vitro cultured in SOF-BSA and changed to SOF-FBS after 48 hours. High fertilization/cleavage rate was observed in oocytes cultured with cumulus cells (29.0 %) compared to the denuded oocytes (20.0 %) for 2-4 cells stage. Day 7 blastocysts were more (P<0.05) on oocytes cultured with cumulus cells (32 %) compared to denuded oocytes (13 %). In experiment 4: The matured oocytes were fertilized using fresh and frozen thawed semen. The oocytes fertilized with frozen thawed semen obtained a better number of 2-4 cell cleavage (23 %) when compared to fresh semen (19 %). Oocytes that were fertilized with frozen thawed semen also obtained higher morula (13 %) and blastocyst (8 %) compared to fresh semen with morula (3.4 %) and blastocyst (2 %). In conclusion, immature oocytes that were exposed to BCB+ and cultured in M199 supplemented with 10 % FBS, 0.5 μg/ml of FSH, 5 mg/ml of LH and 2 μg/ml of E2 had a higher (P<0.05) number of matured oocytes (extrusion of first polar body) compared to those that were not exposed to BCB (no BCB). Oocytes that were cultured with cumulus cells yielded a higher (P<0.05) number of cleaved embryos compared to the denuded oocytes. Slicing yielded a higher (P<0.05) number of oocytes, however the quality of oocytes recovered was similar compared to those recovered by the aspiration technique (P>0.05). Oocytes fertilized with frozen thawed semen yielded higher (P<0.05) number of 2-4 cell, morula and blastocyst when compared with oocytes that were fertilized using fresh semen. Keywords: ovaries, oocytes, slicing, aspiration, COCs, BCB, polar body and cattle

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