Thesis (M Arch)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: John Brittingham. Includes bibliographical references (leaves 90-92).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains x, 61 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 59-61).

Silicon reliability has reemerged as a very important problem in digital system design. As voltage and device dimensions shrink, combinational logic is becoming sensitive to temporary errors caused by single event upsets, transistor and interconnect aging and circuit variability. In particular, computational functional units are very challenging to protect because current redundant execution techniques have a high power and area overhead, cannot guarantee detection of some errors and cause a substantial performance degradation. As traditional worst-case design rules that guarantee error avoidance become too conservative to be practical, new microarchitectures need to be investigated to address this problem. To this end, this dissertation introduces Self-Imposed Temporal Redundancy (SITR), a speculative microarchitectural temporal redundancy technique suitable for pipelined computational functional units. SITR is able to detect most temporary errors, is area and energy-efficient and can be easily incorporated in an out-of-order microprocessor. SITR can also be used as a throttling mechanism against thermal viruses and, in some cases, allows designers to design very aggressive bypass networks capable of achieving high instruction throughput, by tolerating timing violations. To address the performance degradation caused by redundant execution, this dissertation proposes using a tiled-data ow model of computation because it enables the design of scalable, resource-rich computational substrates. Starting with the WaveScalar tiled-data flow architecture, we enhance the reliability of its datapath, including computational logic, interconnection network and storage structures. Computations are performed speculatively using SITR while traditional information redundancy techniques are used to protect data transmission and storage. Once a value has been verified, confirmation messages are transmitted to consumer instructions. Upon error detection, nullification messages are sent to the instructions affected by the error. Our experimental results demonstrate that the slowdown due to redundant computation and error recovery on the tiled-data flow machine is consistently smaller than on a superscalar von Neumann architecture. However, the number of additional messages required to support SITR execution is substantial, increasing power consumption. To reduce this overhead without significantly affecting performance, we introduce wave-based speculation, a mechanism targeted for data flow architectures that enables speculation only when it is likely to benefit performance. / text

Grâce aux progrès réalisés dans le domaine des semi-conducteurs, les plateformes matérielles embarquées sont capables de satisfaire les contraintes de performances d'applications de plus en plus complexes. Cette augmentation conduit à une explosion des coûts de conception, ce qui pousse les concepteurs de ces plateformes à utiliser des outils travaillant à des niveaux d'abstraction plus élevés. Aujourd'hui, les outils de synthèse de haut niveau opèrent sur des descriptions C/C++ pour en générer des accélérateurs matériels spécialisés. Ces outils offrent des gains en productivité significatifs par rapport à la génération précédente, qui opérait sur des descriptions structurelles de l'architecture en VHDL ou Verilog. Ces descriptions algorithmiques doivent être retravaillées pour que les outils puissent générer des circuits performants. Pour faciliter cette tâche, une solution consiste à mettre en œuvre une boite à outils pour des transformations source-à-source orientées synthèse de haut niveau. En particulier, cette thèse s'intéresse aux transformations de boucles, avec pour objectif d'améliorer les performances en exposant des boucles parallèles et en améliorant la localité des accès mémoire. En nous appuyant sur une représentation des boucles dans le modèle polyédrique, nous proposons une approche qui améliore l'applicabilité du pipeline de nids de boucles en vérifiant sa légalité de manière plus précise que les approches existantes. De plus, lorsque la vérification échoue, nous proposons une technique de correction qui insère statiquement des états d'attente pour assurer la légalité du pipeline. Enfin, ce pipeline est mis en œuvre en utilisant une technique de génération de code qui met les nids de boucles à plat. Ces contributions ont été implémentées dans l'infrastructure de compilation source-à-source Gecos, avant d'être appliquées à un ensemble de benchmarks représentatifs des noyaux de calculs cibles de la synthèse de haut niveau. Les résultats montrent un gain en performances significatif, avec un surcoût en surface modéré.

The increasing usage of personal computers and Internet in organizations made it possible to create, edit and share various documents between different employees of the organization. However, document management becomes very troublesome, especially if several employees can contribute changes to a singe document: it is very hard to locate latest document version, or determine which changes to the document were made by which employee. Document management systems are aimed to solve these problems. However these systems often are highly specialized and very costly to implement, or they are general-purpose and hard to customize and apply to organization business domain. Inabilities to customize often arise from strict and inflexible metadata model, used in document management system. The aim of this work is propose abstract document metadata definition and processing model, based on XML data definition language and concept of XML data processing pipeline. The proposed model is general-purpose and highly flexible at the same time, enabling to apply model to any business domain and customize it to reflect any features specific to this domain.

Baigiamajame darbe pateikiama Jurbarko miesto, Vydūno gatvės vandentiekio ir nuotekų surinkimo tinklų vamzdynų būklės analizė. Tyrimų pradžioje vandentiekio ketinių vamzdžių linija (160 m ilgio) buvo diagnozuota televizinės įrangos GULLYVER pagalba. Nustatyta, kad vamzdyje yra išilginis trūkimas. Ištyrus esamas aplinkybes, priimtas sprendimas renovuoti vamzdyną betranšėjiniu būdu priverstinio įtraukimo metodu. Pasirinktas įrenginys Grundotrack „Mini – Gigant“. Nustatyta, kad norint atstatyti nusidėvėjusį vandentiekio vamzdyną, būtina įtraukti naują PE slėginį vandentiekio vamzdį 200 mm skersmens. Grundotrack „Mini – Gigant“ įrenginiu sulaužius senus ketinius vamzdžius, PE vamzdžiai įtraukti be kliūčių. Suskaičiavus darbų sąmatas nustatyta, kad naujo vamzdžio įtraukimas priverstiniu būdu, naudojant betranšėjas technologijas, kainavo 89168 Lt. Tokio pat vamzdžio paklojimas atviru būdu (iškasant tranšėjas) būtų kainavę 108008 Lt. Nuotakyno sistema (380 m ilgio) iš keramikinių 300 mm skersmens vamzdžių pirmiausia buvo diagnozuojama telekamera TELEMEC 100. Nustatyta, kad vamzdynas labai blogos būklės (išilginiai, skersiniai trūkimai, vamzdžio sandurų prasikeitimai ir trūkimai) ir reikalinga skubi vamzdyno renovacija. Ištyrus esamas aplinkybes, priimtas sprendimas renovuoti vamzdyną betranšėjiniu būdu, taikant rankovės metodą. / The final paper analyses the condition of the water supply and sewerage collection network pipelines of Vydūno street, Jurbarkas. First of all, the line of the cast iron pipes (160 meter long) of the water supply system were diagnosed by the use of the television equipment GULLYVER. Longitudinal split in the pipe was discovered. Upon examination of the existing circumstances, the decision was made to renovate the pipeline by trenchless mode, by applying forced pulling method. The device Grundotrack Muni – Gigant was selected for completion of this task. It was established that in order to restore the worn water supply pipeline, a new PE pressure water supply pipe of 200 mm diameter needs to be installed. After the old cast iron pipes were broken by the device Grundotrack Mini - Gigant, the PE pipes were installed without any problems. Having calculated the work estimates, it was established that installation of the new pipe by forced method, through application of trenchless technologies, cost LTL 89168. Open laying (by excavating trenches) of the same pipe would have cost LTL 108008. The sewerage system (380 meter long) consisting of 300 mm diameter ceramic pipes was initially diagnosed by camera TELEMEC 100. Very poor condition of the pipeline was determined (longitudinal, cross fractures, changes and fractures of the pipe joints) and need for urgent renovation of the pipeline was established. Upon examination of the existing circumstances, the decision was made to... [to full text]

ABSTRACT SWIMMING UPSTREAM: A STUDY OF BLACK MALES AND THE ACADEMIC PIPELINE Rhonda D. Wilkins Post secondary participation and graduation rates of Black males are declining rapidly. Black women, however, are realizing substantial growth in both of these areas and account for the majority of the increase in Black student college enrollment. This qualitative case study addresses the decline in Black male participation in higher education by focusing on six Black men who completed college programs and the academic pipeline that brought them to their degree. The purpose of the research inquiry was to determine various factors that either helped or hindered the academic progression of the six Black male participants. For the study participants the two-year college was a component of their academic pipeline and was assessed based on its function as a conduit aiding degree attainment. The common factors that emerged from the findings as influential to the academic progression of the six Black males were categorized as: (a) personal attributes and perceptions, (b) relationships and external influences, and (c) institutional factors. The personal attributes of the participants included self-efficacy, endurance and resilience, and self-regulation. These attributes were framed within the central context of personal agency. Factors external to the participants consisted of family messages about higher education, role models, mentors and advocates, early exposure to college and participation in athletic sports. The institutional factors that surfaced were insufficient college preparation in high school, contrasts between the climate and culture of the two-year college and four-year institution, the lack of promotion of the transfer function at the two-year college. Race and gender were also considered relative to the men and their experiences with the academic pipeline. The salient factors included: (a) the general social and economic conditions faced by young Black males, (b) the perpetuation of negative or one-dimensional stereotypes in the media, (c) pre-college educational inequities, (d) the lack of assistance with college transition, and (e) the unwelcoming climates and lack of Black faculty at predominately white institutions. The study concluded that Black males may face many hurdles to postsecondary attainment and will therefore require personal, family, community, and institutional forces to push them through the academic pipeline.

The early detection of damage of in-service structural or mechanical systems is of vital importance. With early detection, the damage may be repaired before the integrity of the system is jeopardized, avoiding possible monetary losses, environmental impacts, injury and death. With this goal in mind, many structural health monitoring techniques have been developed which use a combination of sensors and algorithms to collect, process and interpret data to detect damage in a structure. This thesis presents work completed in support of the experimental validation of a novel structural health monitoring technique developed with the aim of providing improved qualitative results compared to those methods currently available.

Modern superscalar pipelines have tremendous capacity to consume the instruction stream. This has been possible owing to improvements in process technology, technology scaling and microarchitectural design improvements that allow programs to speculate past control and data dependencies in the superscalar architecture. However, the speed of the memory subsystem lags behind due to physical constraints in bringing in huge amounts of data to the processor core. Cache hierarchies have subdued the impact of this speed gap; however, there is much that can be still done in improving microarchitecture. Data prefetching techniques bring in memory content significantly before the instruction stream actually witnesses demand misses. However, a majority of the techniques proposed so far depend upon an initial demand miss that initiates a stream of previously identified prefetches. In this thesis, we propose a novel prefetching algorithm, which leverages branch prediction to facilitate deep memory system speculation. The branch predictor directed lookahead mechanism builds a speculative control flow path for the instruction stream about to be fetched by the main superscalar pipeline. Prefetches are generated along this speculative path from a condensed representation of the memory instructions, leveraging register index based correlation. The technique integrates eloquently with the main pipeline's branch predictor to filter out prefetches along invalid speculative paths. Impact of the prefetching scheme is analyzed using out- of-order model of the Gem5 cycle accurate simulator. Evaluation shows that on a set of 13 memory intensive SPEC CPU2006 benchmarks, our prefetching technique improves performance by an average of 5.6% over the baseline out-of-order processor.

A study of gouges and dents in the context of pipelines has been completed, using the non-destructive evaluation (NDE) techniques of magnetic flux leakage (MFL) and magnetic Barkhausen noise (MBN). The research is part of an ongoing effort by the Applied Magnetics Group (AMG) at Queen's University to improve the interpretation of the MFL signal, which is used extensively by industry for defect detection and evaluation. The gouges were found to have distinctive MFL signatures depending on their orientation relative to the magnetization axis. Features in the MFL signal were identified as superpositions of geometry-related effects and strain or work hardening of the surface material. A qualitative magnetic permeability distribution in the material near a gouge has been proposed. The distribution is expected to vary in magnitude and extent according to the defect severity. The MFL results of the dent studies, on samples made available by Gaz de France (GdF), largely agreed qualitatively with previous research of dents. However, the differences pointed to the need for study of more varied dent shapes; new signal features were observed that suggested tensile residual strain in the dent rim is more prominent than earlier studies and modeling have predicted. Additionally, upgrades made to the MFL scanning system used by the AMG and a novel approach for building computer models are detailed. / Thesis (Master, Physics, Engineering Physics and Astronomy) -- Queen's University, 2009-09-24 17:13:12.775