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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.
21

µProfiler: A Concurrent Profiler for Concurrent C++ (µC++)

Gidzinski, Justyna Jay January 2007 (has links)
A concurrent program, unlike a sequential program, has multiple threads of execution, resulting in numerous advantages (e.g., faster execution), but also in complex and unpredictable interaction. As a consequence, a concurrent program can easily underutilize available parallelism, and performance can be extremely difficult for users to predict and analyze on their own. A profiler is a tool that can help a user identify as well as locate potential performance problems in a program. Profiling is accomplished through monitoring of the program execution, and analyzing and visualizing the collected performance data. A profiler must display useful information in a way that allows a user to effectively and efficiently understand and analyze a program's behaviour. This thesis describes the advancement in design and implementation of µProfiler, a profiler for sequential and concurrent programs written in µC++. µC++ is a concurrent dialect of the C++ programming language, which executes in uni-processor and multi-processor shared-memory environments. Major advancements to three µProfiler metrics are presented: the Execution State, the Exact Routine Call-Graph and the Statistical Routine Call-Graph. The Execution State metric charts each state for every thread over the entire execution of the program. With high overhead and perfect accuracy, the Exact Routine Call-Graph metric provides an exact call-graph profile of the program's dynamic execution, describing the control flow among routines. With low overhead and less accuracy, the Statistical Routine Call-Graph metric provides a statistical call-graph profile of the program's dynamic execution. For each metric, advancements were made throughout the profiling process (i.e., monitoring, analysis and visualization), addressing goals such as scalability, functionality, usability and performance. The metrics provide reasonable memory overhead and, based on the comparison to related work, are state-of-the-art in functionality and provide similar run-time performance.
22

Research on Searching and Positioning of Buried Underwater Pipelines

Hsiao, Po-yuan 03 February 2005 (has links)
In recent years, ocean has become a place to dispose of industrial and civil waste waters. Hence, there are more and more projects to establish offshore outflow pipes. These underwater pipes should be kept monitored in order to maintain their functions specifically. The purpose of this research was to explore the two outflow pipes in Kaohsiung offshore area, i.e., Chung-chou outflow pipe and Tso-ying outflow pipe, by using an integrated surveying system which includes a side-scan sonar and a sub-bottom profiler. The ultimate objective was to investigate the feasibility of this system in searching and positioning of buried underwater pipelines. Based on this investigation, the offshore section of Chung-chou outflow pipe is about 2.8km in length and extends offshore to the direction of 38o from the west to the south. The water depth at the end of this pipe is about 21m. Among the 2.24km section initiated at the offshore end of the pipe, the buried depths are between 2.2m and 3.2m. There are two disposed gravel zones around the offshore end of the pipe. The first zone is about 130m in length and 10m wide. The second zone is 220m in length and 20m wide. Moreover, based on the side scan sonar images, there are 71 protective concrete blocks located around Chung-chou outflow pipe. The offshore section of Tsao-ying outflow pipe is about 4.76 km in length and extends to the direction of 20o from the west to the south. The water depth at the end of this pipe is about 17m. Among the 3.7km section initiated at the offshore end of the pipe, the buried depths are about 1.0 to 2.5m. A disposed gravel zone with dimensions of 330m in length and 10m wide is located at the end of this pipe. In addition, there are 43 protective blocks located around this outflow pipe. This investigation, incorporated the results conducted on the other three underwater outflow pipes(i.e., Chishui creek outflow pipe, Chinese Petroleum Corporation underwater petroleum pipe off Kaohsiung Harbor and Liuchiuyu water transport pipe), concluded that as far as the buried underwater pipes that are thicker than 1m in diameter are concerned, the integrated system of side scan sonar and sub-bottom profiler provides an useful and trustful tool to get the locations and the buried depth of outflow pipes, as well as the distribution of the protective concrete blocks around these pipes. As to the pipes that are less than 20cm in diameter, the pipes can¡¦t be detected by this equipment. For the pipes that are between 20cm and 1m in diameter, due to limited information collected up to this moment, extensive investigation need to be conducted until a clear understanding can be deduced.
23

An investigation of atmospheric temperature, humidity and cloud detection techniques over the Arctic marine cryosphere.

Candlish, Lauren 08 April 2011 (has links)
The veracity of a Radiometric Microwave Profiling Radiometer (MWRP) while mounted onboard a ship in the Arctic marine environment was assessed. The MWRP was validated against radiosonde data by calculating the RMS and bias for simultaneous measurements taken for temperature and absolute humidity profiles. The vertical resolution of the MWRP was calculated using the inter-level covariance method. Based on the comparisons, the MWRP provided reliable measurements of both temperature and absolute humidity while mounted on the CCGS Amundsen. Satellites CloudSat and Calipso were assessed over the Arctic marine cryosphere. Temperature and absolute humidity from the ECMWF-aux data product was compared with profiles from the ship based MWRP. The cloud base heights measured by the ceilometer and MWRP were compared to CloudSat and Calipso's GeoProf-lidar. Due to a large number of possible false detections, the constraints used by the GeoProf-lidar data product for cloud detection may need to be further refined.
24

An investigation of atmospheric temperature, humidity and cloud detection techniques over the Arctic marine cryosphere.

Candlish, Lauren 08 April 2011 (has links)
The veracity of a Radiometric Microwave Profiling Radiometer (MWRP) while mounted onboard a ship in the Arctic marine environment was assessed. The MWRP was validated against radiosonde data by calculating the RMS and bias for simultaneous measurements taken for temperature and absolute humidity profiles. The vertical resolution of the MWRP was calculated using the inter-level covariance method. Based on the comparisons, the MWRP provided reliable measurements of both temperature and absolute humidity while mounted on the CCGS Amundsen. Satellites CloudSat and Calipso were assessed over the Arctic marine cryosphere. Temperature and absolute humidity from the ECMWF-aux data product was compared with profiles from the ship based MWRP. The cloud base heights measured by the ceilometer and MWRP were compared to CloudSat and Calipso's GeoProf-lidar. Due to a large number of possible false detections, the constraints used by the GeoProf-lidar data product for cloud detection may need to be further refined.
25

Raindrop Size Distribution Retrieval And Evaluation Using An S-band Radar Profiler

Fang, Fang 01 January 2004 (has links)
Vertical pointing Doppler radar profilers are used to explore the vertical structure of precipitation cloud systems and to provide validation information for use in weather research. In this thesis, a theoretical radar rain-backscatter model was developed to simulate profiler Doppler spectra as a function of assumed rain parameters, of which the raindrop size distribution (DSD) is the fundamental quantity used to describe the characteristics of rain. Also, profiler observations during stratiform rain are analyzed to retrieve the corresponding rain DSD’s. In particular, a gamma distribution model is introduced, which uses Rayleigh scattering portion of the Doppler velocity spectrum to estimate the raindrop size distribution. This theoretical scattering model was validated by simulating atmospheric profiles of precipitation Doppler spectra and three moments (reflectivity, mean Doppler velocity and spectral width) and then comparing these with the corresponding measurements from an S-band radar profiler during a NASA conducted Tropical Rainfall Measuring Mission (TRMM) field experiment in Central Florida in 1998. Also, the results of my analysis yielding precipitation retrievals are validated with an independent, simultaneous Joss-Waldvogel Disdrometer rain DSD observations that were collocated with the radar profiler.
26

History, Ideology, and Evolution of Criminal Profiling

Ramesh, Gayatri M 01 January 2021 (has links)
Criminal profiling is the art of using evidence and crime scenes to deduce who the criminal is and where the criminals might be going next. In addition, criminal profiling is also used to link cases together with like victims. While its usage in law enforcement is relatively new, forms of the art have been around for decades. This thesis researches the history, ideology, and evolution of criminal profiling from the early 1870s to its current state. Cesare Lombroso and his research founded criminal profiling by examining how criminals and their minds vary from law-abiding citizens. Following Lombroso, various forms of research were conducted to further criminal profiling into the much more tangible craft that it is today. Various researchers looked into differing aspects of criminal profiling and produced research that has revolutionized the process. In its earliest stages, biological factors were the primary factors considered to explain why criminals behave differently. However, over time, sociological, environmental, and even psychological factors have been shown to play a part in this volatile recipe. While the process of criminal profiling is not perfect, the advancements in our understanding of the human psyche, along with the evolution of technology, have caused criminal profiling to become much more of a refined art today than in years past. Further, there is reason to believe that the future of profiling will continue to evolve and become even more helpful as a tool for law enforcement. Law enforcement has begun to assemble big data, and informaticians have started to link social media posts, criminal confinements, and online purchases to criminally deviant and violent behavior.
27

Modeling rating curves from close-range remote sensing data : Application of laser and acoustic ranging instruments for capturing stream channel topography

Lam, Norris January 2017 (has links)
A rating curve provides a functional relationship between water height (i.e. stage) and discharge at a specified cross-section in a river. Used in combination with a time series of stage, rating curves become one of the central components for generating continuous records of streamflow. Since developing and maintaining rating curves can be time consuming, hydraulic models have shown potential to reduce the effort required for developing rating curves. A central challenge with modeling procedures, however, is the acquisition of accurate stream channel and floodplain topography. From this perspective, this thesis focuses on the real-world application of close-range remote sensing techniques such as laser-based ranging technologies (i.e. Light detection and ranging or LiDAR) or acoustic based ranging technologies (i.e. acoustic Doppler current profiler or ADCP) to capture topographic information for hydraulic modeling applications across various spatial scales. First, a review of the current LiDAR literature was carried out to identify potential ways to take full advantage of these novel data and technologies in the future. This was followed by four interconnected studies whereby: (i) a low-cost custom laser scanning system was designed to capture grain size distributions for a small stream; (ii) synthetically thinned airborne laser scanning (ALS) data was applied in a physically-based hydraulic modelling framework to develop rating curves; (iii) low-resolution national-scale ALS was coupled with ADCP bathymetry to be used in conjunction with a hydraulic model to develop rating curves; and (iv) the impact of measurement uncertainties on generating rating curves with a hydraulic model were investigated. This thesis highlights the potential of close-range remote sensing techniques for capturing accurate stream channel topography and derive from these data, the necessary parameters required for hydraulic modeling applications. / En avbördningskurva tillhandahåller ett funktionellt förhållande mellan vattendjup (dvs. vattenstånd) och flöde vid ett specifikt tvärsnitt i ett vattendrag. Avbördningskurvan blir en central komponent för generering av kontinuerliga tidsserier av vattenföring från tidsserier av vattenstånd. Eftersom det är tidskrävande att utveckla och underhålla avbördningskurvor erbjuder hydrauliska modeller attraktiva möjligheter att minska den insats som krävs för att utveckla avbördningskurvorna. En central utmaning för sådana modelleringsförfaranden är emellertid tillgången till noggrann topografidata av strömfåran och de omgivande stränderna. Den här avhandlingen fokuserar på tillämpningen av fjärranalystekniker för avståndsmätning på nära håll, såsom laserbaserade teknik (dvs. Light detection and ranging eller LiDAR) och akustisk baserat teknik (dvs. acoustic Doppler current profiler eller ADCP), för att fånga topografisk information för hydraulisk modellering av vattendrag i olika rumsliga skalor. Först presenteras en litteraturstudie av den nuvarande LiDAR-litteratur för att identifiera potentiella sätt att dra full nytta av dessa nya data och tekniker i framtiden. Detta följs av fyra sammanlänkade studier: (i) tillämpning av ett lågkostnads-laseravsökningssystem för att fånga kornstorleksfördelningar i ett litet vattendrag, (ii) syntetiskt förtunnad flygburen laserskanningsdata (ALS) applicerad i en fysiskt baserad hydraulisk modell för att utveckla avbördningskurvor, (iii) lågupplösta ALS från Svensk nationell höjdmodell kopplade med ADCP-batymetri för att ta fram en avbördningskurva med en hydraulisk modell, och (iv) undersökning av effekterna av osäkerheter på mätdata för att generera avbördningskurvor med en hydraulisk modell. Denna avhandling belyser potentialen för fjärranalystekniker för avståndsmätning på nära håll, för att fånga strömfårans exakta topografi och ifrån dessa data härleda de parametrar som krävs för hydrauliska modelleringstillämpningar. / <p>At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 5: Manuscript.</p>
28

Contribuição para a avaliação da irregularidade longitudinal de pavimentos com perfilômetros inerciais. / Contribution for pavements longitudinal roughness evaluation with inertial profilers.

Barella, Rodrigo Maluf 18 December 2007 (has links)
A presente pesquisa engloba a análise de diversos aspectos a respeito da avaliação de irregularidade longitudinal de pavimentos, tratando mais detidamente das situações em que tal avaliação é executada a partir de perfis longitudinais medidos com perfilômetros inerciais, tipo de equipamento que também é objeto de exame. A análise é iniciada com o entendimento da evolução histórica deste tipo de avaliação funcional que abrange não só os equipamentos, como também os métodos de avaliação e os índices de irregularidade utilizados no Brasil. O trabalho relata as principais etapas do desenvolvimento do perfilômetro inercial que foi usado nesta pesquisa, seus aspectos técnicos e operacionais, além dos resultados dos testes que evidenciaram seu funcionamento e também uma comparação com os resultados obtidos por um medidor de irregularidade do tipo resposta. A pesquisa é completada com uma série de análises a respeito do método mais adequado para a verificação do funcionamento de perfilômetros inerciais, abarcando importantes recomendações para a escolha e medição de perfis de referência indispensáveis em tais verificações. São discutidos importantes aspectos do processamento de perfis para a determinação do QI que concluíram pela indicação da redução do espaçamento entre pontos do perfil para 25 cm. As incertezas dos índices QI e IRI obtidos a partir de perfilômetros inerciais são também abordadas, sendo que se constatou que o índice QI é afetado por grandes comprimentos de onda que normalmente não são considerados como irregularidade. A correlação entre os índices QI e IRI é amplamente avaliada através de dados reais de perfis de centenas de quilômetros de rodovias, que evidenciaram a existência de grande dispersão em tal correlação indicando que o melhor é não correlacioná-los. Por fim, a pesquisa deixa como legado a proposta de um anteprojeto de norma brasileira para este tipo de avaliação que abarca os julgamentos de todo o trabalho. / This research includes de analysis of several aspects regarding longitudinal pavement roughness evaluation, more specifically when these evaluations are done using an inertial profiler - kind o equipment that is also an object of this study. The analysis is initiated with the comprehension of the historical evolution of this type of functional evaluation that not only encloses equipment, but also the methods and the roughness indexes more common in Brazil. The main stages throughout of the development of the inertial profiler used on this research, its technical and operational features, the results of the tests that proved its good functionality and also the comparison of the results obtained with a response type roughness meter were incorporated. The research is completed with a series of analysis regarding the methods more appropriate for the verification of inertial profilers functioning, including important recommendations for the choice and measurement of reference profiles, indispensable in such verifications. Important aspects concerning profiles processing for the QI determination were verified and concluded for reduction of the displacement between the profile elevations for 25 cm. The uncertainties of QI and IRI indexes obtained from inertial profiles measurements were also researched and at this opportunity it was verified that value of QI is affected by long wavelengths that usually are not considered roughness. The correlation between QI and IRI indexes were widely evaluated using real data of hundreds of kilometers of highways profiles, and evidenced the existence of a great dispersion in such correlation what indicates that the best recommendation is not to correlate them. Finally, this research leaves as a legacy the proposal of a first draft for a Brazilian standard for this type of roughness evaluation that accumulates most of the judgments presented here.
29

Quantitative Analysis of High Resolution Chirp Sub-Bottom Profiler Data in Shallow Marine Sediments

Abushaheen, Yahya Rhadi January 2016 (has links)
Thesis advisor: John E. Ebel / This research describes a method to carry out quantitative analyses of sub-seabed sediments using high-resolution chirp seismic profiles in order to estimate the properties of subsurface sediments. The method identifies significant sedimentary interfaces, extracts them from the seismic record, and measures the inelastic attenuation coefficients (k) of the sedimentary layers. The k values and their variations with increasing depth of sediments are indicative of the amount of compaction of the sediment. The k values are correlated with borehole lithology to provide a relationship between k measurements and local borehole lithology. Once determined for an area, the correlation can be applied to other seismic records from the area to analyze sedimentary properties even if no borehole lithology is locally available. / Thesis (MS) — Boston College, 2016. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Earth and Environmental Sciences.
30

Myteri på Tinder : hur användare bryter eller följer Tinders normer och design i skapande av profiler

Lunde, Lukas January 2019 (has links)
Tinder is a specific context for interaction. Tinder is an online dating service that differs from the norm in online dating. User expression is limited on Tinder, this emphasises user ́s choices in the creation of profiles. A strong gamification design further emphasises this. This study has examined how users followed or broke Tinder’s norms and design, in the creation of their profiles. 1001 Tinder profiles where examined. The study found that users consciously went against Tinder ́s norms and design, sometimes via the use of Tinder ́s own design solutions. These behaviours sometimes circumvented core aspects of Tinder, and sometimes caused decreased security for users. The study also showed a difference in maleand female users. Male users were almost twice as likely to include their profession then female users. Female users on the other hand were more likely to be younger than their Tinder profiles stated.

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