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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.
101

Does Rust SPARK joy? : Recommendations for safe cross-language bindings between Rust and SPARK

Maiga, Aïssata January 2023 (has links)
This thesis aims to provide recommendations for interfacing two memory-safe programming languages, Rust and SPARK. The comparison of Rust and C/C++, as well as SPARK and C/C++, has been thoroughly researched. However, this level of investigation hasn’t been as extensive between memory-safe languages. SPARK is a subset of Ada, a programming language with a long track record in safety-critical applications. Rust is a multi-paradigm language that has gained popularity since its emergence roughly a decade ago. Both languages implement ownership systems and type safety, which are instrumental in developing safe and reliable software. Memory-safety bugs in code written in C/C++ account for about 70 % of major vulnerabilities in the industry, as reported by organizations such as Microsoft, Apple, and Google. While tools to avoid memory errors exist, code cannot be made safe retroactively, which creates a need for languages designed with safety in mind, such as Rust and SPARK. Combining those two languages is a very promising path for low-level and systems programming and safety-critical applications (automotive, avionics, medical etc.). This thesis identifies best practices for safe bindings between Rust and SPARK, focusing on ensuring memory safety, type safety, and ownership, and then analyzes how to maintain or transfer those properties. The thesis provides clear recommendations based on control study programs and a real-world example using BBQueue, a circular buffer library suitable for embedded systems implemented in both languages. The identified best practices can be used for safe bindings and automated tools/code generation. This thesis fills a gap in existing research, primarily focusing on combining safe and unsafe languages. It provides a valuable contribution to software security and safety-critical systems. / Denna avhandling syftar till att ge rekommendationer för att koppla samman två minnessäkra programmeringsspråk, Rust och SPARK. Sådana kombinationer har redan studerats utförligt mellan Rust/SPARK och de osäkra språken C/C++, men det finns relativt lite information och forskning angående minnessäkra språk. SPARK är en delmängd av Ada, ett språk som har använts i decenier i säkerhetskritiska applikationer. Rust är ett multiparadigmatiskt språk som har blivit populärt sedan dess skapande för ungefär ett decennium sedan. Båda språken implementerar ägarskapssystem och typsäkerhet, vilka är avgörande för att utveckla säkra och tillförlitliga programvaror. Minnesfel i C/C++ står för cirka 70 procent av de stora sårbarheterna i branschen, som rapporterats av organisationer såsom Microsoft, Apple och Google. Även om det finns verktyg för att undvika minnesfel kan koden inte göras säker retroaktivt, vilket skapar ett behov av språk som är designade med säkerhet i åtanke. Att kombinera Rust och SPARK är en mycket lovande väg för systemprogrammering, låg nivå och säkerhetskritiska applikationer (bilindustri, flygavionik, medicinskt etc). Denna avhandling identifierar bästa praxis för säkra bindningar mellan Rust och SPARK, med fokus på att säkerställa minnessäkerhet, typsäkerhet och ägarskap, och analyserar sedan hur man kan behålla eller överföra dessa egenskaper. Avhandlingen ger klara rekommendationer baserade på kontrollstudieprogram och ett exempel med hjälp av BBQueue, ett cirkulärt buffertbibliotek som används i inbyggda system. Dessa resulat kan användas för att skapa säkra bindningar, manuelt eller med ett automatiserat verktyg. Denna avhandling fyller en lucka i befintlig forskning, som främst fokuserar på att kombinera säkra och osäkra språk. Den bidrar värdefullt till programvarusäkerhet och säkerhetskritiska system.
102

A conceptual design of a Software Base Management System for the Computer Aided Prototyping System

Galik, Daniel 12 1900 (has links)
Approved for public release; distribution is unlimited / This thesis builds upon work previously done in the development of the Computer Aided Prototyping System (CAPS) and the Prototype System Description Language (PSDL), and presents a conceptual design for the Software Base Management System (SBMS) component of CAPS. The SBMS is the most critical component of CAPS as it will coordinate the retrieval and integration of Ada software modules. A robust SBMS that enables a software system designer to successfully retrieve reusable Ada components will expedite the prototype development process and enhance designer productivity. Implementation of the conceptual design will be the basis for further work in this area. (Ada is a registered trademark of the United States Government, Ada Joint Program Office.) / http://archive.org/details/conceptualdesign00gali / Lieutenant Commander, United States Navy
103

A Static Scheduler for critical timing constraints

Marlowe, Laura C. 12 1900 (has links)
Approved for public release; distribution is unlimited / The Computer Aided Prototyping System (CAPS) and the Prototype System Description Language (PSDL) represent a pioneering effort in the field of software development. The implementation of CAPS will enable software engineers to automatically validate design specifications and functional requirements early in the design of a software system through the development and execution of a prototype of the system under construction. Execution of the prototype is controlled by an Execution Support System (ESS) within the framework of CAPS. One of the critical elements of the ESS is the Static Scheduler which extracts critical timing constraints and precedence information about operators from the PSDL source that describes the prototype. The Static Scheduler then uses this information to determine whether a feasible schedule can be built, and if it can, constructs the schedule for operator execution within the prototype. / http://archive.org/details/staticschedulerf00marl / Lieutenant Commander, United States Navy
104

Obten??o e aplica??o de sistemas microemulsionados na recupera??o avan?ada de petr?leo

Albuquerque, Heraldo da Silva 10 February 2008 (has links)
Made available in DSpace on 2014-12-17T15:41:44Z (GMT). No. of bitstreams: 1 HeraldoSA_capa_ate_cap4_conclusao_e_referencias.pdf: 658887 bytes, checksum: 11fc03947cae68eafc72706a5e9ce665 (MD5) Previous issue date: 2008-02-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Due to the need of increasing production in reservoirs that are going through production decline, methods of advanced recovery have frequently been used in the last years, as the use of conventional methods has not been successful in solving the problem of oil drifting. In this work, the efficiency of different microemulsionated systems in the flow of oil from cores from Assu and Botucatu formations. Regarding drifting tests, cores were calcinated at a temperature of 1000?C, for 18 hours, with the aim of eliminating any organic compound present in it, increasing the resultant permeability. Following, the cores were isolated with resin, resulting in test specimens with the following dimensions: 3.8 cm of diameter and 8.7 cm of length. Cores were saturated with brine, composed of aqueous 2 wt % KCl, and oil from Guamar? treatment station (Petrobras/RN). A pressure of 20 psi was used in all tests. After core saturation, brine was injected again, followed by oil at constant flow rate. The system S3 - surfactant (anionic surfactant of short chain), isoamillic alcohol, pine oil, and water - presented the best drift efficiency, 81.18%, while the system S1E commercial surfactant, ethyl alcohol, pine oil, and distilled water presented low drift efficiency, 44,68% / Diante da necessidade de aumentar a produ??o de reservat?rios que se encontram em decl?neo de produ??o, os m?todos de recupera??o avan?ada v?m sendo bastante utilizados nos ?ltimos anos, visto que apenas os m?todos convencionais n?o t?m solucionado o problema de deslocamento de ?leo. Neste trabalho estudou-se a efici?ncia de diferentes sistemas microemulsionados no deslocamento de ?leo de testemunhos da forma??o Assu e da forma??o Botucatu. Para os ensaios de deslocamento, os testemunhos foram calcinados a uma temperatura de 1000?C, durante 18 horas, com a finalidade de eliminar qualquer mat?ria org?nica presente e aumentar a permeabilidade. Em seguida, os mesmos foram isolados com resina, apresentando as seguintes dimens?es: 3,8 cm de di?metro e 8,7 cm de comprimento. Para a satura??o dos testemunhos foi utilizado salmoura, composta de KCl a 2% em peso, e ?leo oriundo da Esta??o de Tratamento de Guamar? (Petrobras/RN) e em todos os ensaios utilizou-se press?o de 20 psi. Os ensaios de inje??o seguiram as seguintes etapas: para determinar a permeabilidade inicial, foi injetada salmoura, atrav?s do testemunho, em seguida, com o testemunho saturado com salmoura, foi injetado ?leo, ? vaz?o constante. Ap?s a satura??o do testemunho, foi injetada salmoura novamente a fim de obter o percentual de recupera??o pelo m?todo convencional. Para determinar a recupera??o de ?leo pelo m?todo especial foi injetada microemuls?o no testemunho, ? vaz?o constante. Dentre os resultados obtidos o sistema S3, composto de TC (tensoativo ani?nico de cadeia curta), ?lcool iso-am?lico, ?leo de pinho e ?gua destilada apresentou a melhor efici?ncia de deslocamento, 81,18%. Enquanto que o sistema S1E, composto por TA (tensoativo ani?nico comercial), ?lcool et?lico, ?leo de pinho e ?gua destilada apresentou uma baixa efici?ncia de deslocamento, apenas 44,68%
105

Machine Learning : for Barcode Detection and OCR

Fridolfsson, Olle January 2015 (has links)
Machine learning can be utilized in many different ways in the field of automatic manufacturing and logistics. In this thesis supervised machine learning have been utilized to train a classifiers for detection and recognition of objects in images. The techniques AdaBoost and Random forest have been examined, both are based on decision trees. The thesis has considered two applications: barcode detection and optical character recognition (OCR). Supervised machine learning methods are highly appropriate in both applications since both barcodes and printed characters generally are rather distinguishable. The first part of this thesis examines the use of machine learning for barcode detection in images, both traditional 1D-barcodes and the more recent Maxi-codes, which is a type of two-dimensional barcode. In this part the focus has been to train classifiers with the technique AdaBoost. The Maxi-code detection is mainly done with Local binary pattern features. For detection of 1D-codes, features are calculated from the structure tensor. The classifiers have been evaluated with around 200 real test images, containing barcodes, and shows promising results. The second part of the thesis involves optical character recognition. The focus in this part has been to train a Random forest classifier by using the technique point pair features. The performance has also been compared with the more proven and widely used Haar-features. Although, the result shows that Haar-features are superior in terms of accuracy. Nevertheless the conclusion is that point pairs can be utilized as features for Random forest in OCR.
106

Unequal treatment or uneven consequence: a content analysis of Americans with Disabilities Act Title I disparate impact cases from 1992 - 2012

Johnston, Sara Pfister 01 July 2013 (has links)
The purpose of this research was to examine the patterns and themes of litigation in Americans with Disabilities Act (ADA) disability discrimination cases charged under the theory of disparate impact. Specifically, this study used Computer Assisted Legal Research (CALR) to identify and review all U.S. Appellate Court ADA disparate impact cases as reported by Westlaw, a commercial electronic case law reporting system owned by Thomson Reuters. This study used a two-step, mixed methods approach to analyze the data relevant to the research questions and sub-questions. First, the researcher employed content analysis (Hall & Wright, 2008) to identify and characterize patterns and trends of litigation in all reported U.S. Appellate Court ADA cases charged under the theory of disparate impact from 1992 through 2012. Cases were analyzed chronologically, and variables included number of published and unpublished cases, distribution of jurisdiction, distribution of ADA titles, EEOC involvement, case fact patterns, and characteristics of charging and opposing parties. Frequency analyses were conducted on these data. Second, the researcher identified a subset of the ADA disparate impact cases analyzed in the first step: Title I, or employment discrimination cases. Qualitative analysis employing the constant comparative method (Strauss & Corbin, 1990) was used to identify and characterize patterns and themes of the judicial opinions in the Title I disparate impact cases. The researcher developed a framework for analysis based on a review of the literature of the sociopolitical perspective of disability to guide the analysis of the judicial opinions in the subset of disparate impact cases. The results of the frequency analyses conducted on these data revealed four trends: (a) Precedent, (b) Circuit and Judge Effects, (c) Equal Employment Opportunity Commission (EEOC) Successes, and (d) Sutton Case Effect. The results of the qualitative analysis of the text of the judicial opinions produced four themes and three relationships among the themes. The four themes were accommodation(s); workplace culture, norms, and policies; judicial process; and policy space. The three relationships were gap-filling, weighing and balancing, and maintaining status quo versus effecting social change. The themes and relationships are depicted in a concept map that visually displays the conceptual framework revealed in the study. The findings in this study may inform disability and rehabilitation scholars about ADA disparate impact cases, a body of law about which little is known. The patterns and trends identified in ADA Title I disparate impact cases may provide information about the types of policies and practices that are most frequently litigated. Rehabilitation practitioners may be able to use the results of this research to develop education and outreach strategies for employers on best practices for hiring, accommodating, and promoting employees with disabilities. Because the workplace policies and procedures identified in the cases that comprise this study are neutral on their face rather than intentionally discriminatory, employers may benefit from information that assists them in evaluating their policies and procedures proactively, which may avoid costly and time-consuming litigation. Finally, workplace policies and procedures that fairly represent the essential functions of the job and are applied uniformly to workers with and without disabilities will contribute to a more diverse workforce.
107

Conception d'applications pour systèmes transactionnels coopérants

Bogo, Gilles 18 June 1985 (has links) (PDF)
Les moyens offerts par les systèmes de gestion de base de données et les systèmes transactionnels pour maintenir la cohérence et l'intégrité des systèmes d'information sont tout d'abord analysés tant en centralisé qu'en réparti. La seconde partie est consacrée à l'étude de deux grandes classes de méthodes de conception, l'une fondée sur les modèles de description de données, l'autre sur les types abstraits. Dans chaque cas, une méthode particulière est présentée et analysée. Après présentation de l'application bancaire pilote, la troisième partie définit un modèle pour la description des applications transactionnelles. Celui-ci est appliqué et confronté à l'application pilote. La dernière partie décrit la réalisation de ce modèle dans le langage ADA. Un environnement de conception est construit et se présente comme un sur-ensemble du langage ADA. Enfin, cet outil est comparé à d'autres propositions du domaine de la recherche
108

Open Code Translation from Executable and Translatable UML Models - Implicit Bridging

Löfqvist, Mikael January 2007 (has links)
<p>Executable and Translatable UML (xtUML) is the next abstraction level in software development, where both programming language and software architecture have been abstracted away. xtUML is a well defined UML profile, extended with precise action semantics. This allows the developers to define a problem area, domain, in such a detail that it can be executed. By defining the system with xtUML-models, domains, the system functionality can be verified early in the development process. Translation to code can be done in different ways and this work will be performed in an environment where code is automatically generated with a model compiler.</p><p>The goal with a domain is that it should be independent of other domains, reused without modification and exchanged with another domain solving the same problem. However a domain can make assumptions that certain functionality is available and these assumptions are requirements for another domain.</p><p>To fulfil these goals there must be a minimal coupling between the domains. This can be solved with the technique Implicit Bridging, where the bridge dependency between domains is defined in a bridge. The dependency is in the form of mappings/coupling between elements in both domains. By defining a bridge interface for a server domain a client domain can use the resources offered by the server domain.</p><p>The work performed shows how an implementation of Implicit Bridging could be realized by applying the technique in a microwave oven system. From the system design five different mapping types have been implemented. The applicability and the quality of the implementation have been verified by testing the generated system functionality and also verifying the goals, exchangeability and reuse of domains, of the system.</p>
109

A reconfigurable distributed process control environment for a network of PC's using Ada and NetBIOS.

Randelhoff, Mark Charles. January 1992 (has links)
No abstract / Thesis (M.Sc.-Electronic Engineering)-University of Natal, 1992.
110

Implications of GRACE Satellite Gravity Measurements for Diverse Hydrological Applications

Yirdaw-Zeleke, Sitotaw 09 April 2010 (has links)
Soil moisture plays a major role in the hydrologic water balance and is the basis for most hydrological models. It influences the partitioning of energy and moisture inputs at the land surface. Because of its importance, it has been used as a key variable for many hydrological studies such as flood forecasting, drought studies and the determination of groundwater recharge. Therefore, spatially distributed soil moisture with reasonable temporal resolution is considered a valuable source of information for hydrological model parameterization and validation. Unfortunately, soil moisture is difficult to measure and remains essentially unmeasured over spatial and temporal scales needed for a number of hydrological model applications. In 2002, the Gravity Recovery And Climate Experiment (GRACE) satellite platform was launched to measure, among other things, the gravitational field of the earth. Over its life span, these orbiting satellites have produced time series of mass changes of the earth-atmosphere system. The subsequent outcome of this, after integration over a number of years, is a time series of highly refined images of the earth's mass distribution. In addition to quantifying the static distribution of mass, the month-to-month variation in the earth's gravitational field are indicative of the integrated value of the subsurface total water storage for specific catchments. Utilization of these natural changes in the earth's gravitational field entails the transformation of the derived GRACE geopotential spherical harmonic coefficients into spatially varying time series estimates of total water storage. These remotely sensed basin total water storage estimates can be routinely validated against independent estimates of total water storage from an atmospheric-based water balance approach or from well calibrated macroscale hydrologic models. The hydrological relevance and implications of remotely estimated GRACE total water storage over poorly gauged, wetland-dominated watershed as well as over a deltaic region underlain by a thick sand aquifer in Western Canada are the focus of this thesis. The domain of the first case study was the Mackenzie River Basin wherein the GRACE total water storage estimates were successfully inter-compared and validated with the atmospheric based water balance. These were then used to assess the WATCLASS hydrological model estimates of total water storage. The outcome of this inter-comparison revealed the potential application of the GRACE-based approach for the closure of the hydrological water balance of the Mackenzie River Basin as well as a dependable source of data for the calibration of traditional hydrological models. The Mackenzie River Basin result led to a second case study where the GRACE-based total water storage was validated using storage estimated from the atmospheric-based water balance P-E computations in conjunction with the measured streamflow records for the Saskatchewan River Basin at its Grand Rapids outlet in Manitoba. The fallout from this comparison was then applied to the characterization of the Prairie-wide 2002/2003 drought enabling the development of a new drought index now known as the Total Storage Deficit Index (TSDI). This study demonstrated the potential application of the GRACE-based technique as a tool for drought characterization in the Canadian Prairies. Finally, the hydroinformatic approach based on the artificial neural network (ANN) enabled the downscaling of the groundwater component from the total water storage estimate from the remote sensing satellite, GRACE. This was subsequently explored as an alternate source of calibration and validation for a hydrological modeling application over the Assiniboine Delta Aquifer in Manitoba. Interestingly, a high correlation exists between the simulated groundwater storage from the coupled hydrological model, CLM-PF and the downscaled groundwater time series storage from the remote sensing satellite GRACE over this 4,000 km2 deltaic basin in Canada.

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