• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 15
  • 10
  • 1
  • Tagged with
  • 32
  • 32
  • 30
  • 16
  • 9
  • 8
  • 8
  • 6
  • 5
  • 5
  • 5
  • 4
  • 4
  • 4
  • 4
  • 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.
11

A COMMERCIAL OFF THE SHELF CONTINUOUSLY TUNABLE HIGH DATA RATE SATELLITE RECEIVER

Varela, Julio, Conrad, Robert 10 1900 (has links)
International Telemetering Conference Proceedings / October 23-26, 2000 / Town & Country Hotel and Conference Center, San Diego, California / TSI TelSys, Inc. is in the process of developing a production level, continuously tunable satellite receiver designed to support multiple high data rate, low earth and geostationary orbit missions in the 20 Mbps to 800 Mbps composite QPSK data rate range. This paper will evaluate market demands on satellite receivers and outline receiver design technique as a solution to high rate, multi-mission support.
12

A Low-Cost, Autonomous, Ground Station Operations Concept and Network Design for EUVE and Other Earth-Orbiting Satellites

Abedini, A., Moriarta, J., Biroscak, D., Losik, L., Malina, R. F. 11 1900 (has links)
International Telemetering Conference Proceedings / October 30-November 02, 1995 / Riviera Hotel, Las Vegas, Nevada / The Extreme Ultraviolet Explorer (EUVE) satellite was designed to operate with the Tracking and Data Relay Satellite System (TDRSS) and Deep Space Network (DSN). NASA, the Jet Propulsion Laboratory and the Center for EUV Astrophysics have been evaluating a commercially available ground station already used for NASA's Low Earth Orbit (LEO) weather satellites. This ground station will be used in a network of unattended, autonomous ground stations for telemetry reception, processing, and routing of data over a commercial, secure data line. Plans call for EUVE to be the initial network user. This network will be designed to support many TDRSS/DSN compatible missions. It will open an era of commercial, low-cost, autonomous ground station networks. The network will be capable of supporting current and future NASA scientific missions, and NASA's LEO and geostationary weather satellites. Additionally, it could support future, commercial communication satellites in low, and possibly medium, Earth orbit. The combination of an autonomous ground station and an autonomous telemetry monitoring system will allow reduction in personnel. The EUVE Science Operations Center has already reduced console work from three shifts to one by use of autonomous telemetry monitoring software.
13

PREPARING A COTS GROUND TELEMETRY RECEIVER FOR USE IN THE INTERNATIONAL SPACE STATION

Champion, James 10 1900 (has links)
International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Within the industry, telemetry receivers are used in ground-based telemetry receiving stations to receive telemetry data from air or space-based sources. Equipment for the typical telemetry application is widely available. But when requirements create the need for a space-based telemetry receiver to uplink data from the ground, what are the choices for equipment? In such situations, adapting COTS equipment may present the only solution to meet delivery and budgetary constraints. The first part of this paper provides technical and contractual points a COTS supplier needs to consider when bidding on a COTS contract. The second part of this paper covers a project concerned with modification of a general-purpose ground telemetry receiver for use on the International Space Station. The information within the paper is useful to other engineers and companies considering contracts to modify COTS equipment for use on Shuttle or other space-based projects.
14

A 3-CHANNEL MONOPULSE TRACKING RECEIVER SYSTEM USING COMMERCIAL OFF-THE-SHELF EQUIPMENT

Champion, James 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Three-channel monopulse tracking receiver systems are commonly used for high performance tracking of satellites, missiles, or aircraft to maximize the reception of data. Typically, the receiver in such systems are custom designed for their end purpose. This results in a high cost to cover the development, service, and support of a highly specialized piece of equipment. This paper covers the requirements and performance of a 3-channel monopulse tracking receiver assembled from commercial-off-the-shelf (COTS) equipment. Such a system provides an option for designing or upgrading tracking stations with the lower cost, larger support base, and greater system configuration choices that are available with COTS equipment.
15

Reducing Radio Frequency Susceptibilities in Commercial-Off-the-Shelf Camera Equipment for use in Electromagnetic Compatibility Testing

Mainini, Kevin 01 May 2015 (has links)
The Technical Testing and Analysis Center (TTAC) Group at Oak Ridge National Laboratory performs electromagnetic compatibility testing on various radiation detection units. These tests require remote viewing of the equipment’s display to monitor its compliance with national and international standards. The Commercial-Off-the-Shelf (COTS) camera equipment that is used to monitor the displays exhibits radio frequency susceptibilities causing issues when determining the actual susceptibilities of the device under test. In order to mitigate this issue, a COTS camera was placed in two common test positions and cycled through three angled orientations with various radio frequency shielding methods applied. The development of these shielding methods was investigated in this thesis. The goal was to reduce the number of susceptible frequencies. The reduction of susceptibilities would greatly increase the viewing capacity of the cameras during testing. The techniques discovered have allowed for other COTS camera equipment to be modified and used effectively during electromagnetic compatibility testing.
16

Systematic construction of goal-oriented COTS taxonomies

Ayala Martínez, Claudia Patricia 31 March 2008 (has links)
El proceso de construir software a partir del ensamblaje e integración de soluciones de software pre-fabricadas, conocidas como componentes COTS (Comercial-Off-The-Shelf) se ha convertido en una necesidad estratégica en una amplia variedad de áreas de aplicación. En general, los componentes COTS son componentes de software que proveen una funcionalidad específica, que están disponibles en el mercado para ser adquiridos e integrados dentro de otros sistemas de software. Los beneficios potenciales de esta tecnología son principalmente la reducción de costes y el acortamiento del tiempo de desarrollo, a la vez que fomenta la calidad. Sin embargo, numerosos retos que van desde problemas técnicos y legales deben ser afrontados para adaptar las actividades tradicionales de ingeniería de software para explotar los beneficios del uso de COTS para el desarrollo de sistemas.Actualmente, existe un incrementalmente enorme mercado de componentes COTS; así, una de las actividades más críticas en el desarrollo de sistemas basados en COTS es la selección de componentes que deben ser integrados en el sistema a desarrollar. La selección está básicamente compuesta de dos procesos principales: La búsqueda de componentes candidatos en el mercado y su posterior evaluación con respecto a los requisitos del sistema. Desafortunadamente, la mayoría de los métodos existentes para seleccionar COTS, se enfocan en el proceso de evaluación, dejando de lado el problema de buscar los componentes en el mercado. La búsqueda de componentes en el mercado no es una tarea trivial, teniendo que afrontar varias características del mercado de COTS, tales como su naturaleza dispersa y siempre creciente, cambio y evolución constante; en este contexto, la obtención de información de calidad acerca de los componentes no es una tarea fácil. Como consecuencia, el proceso de selección de COTS se ve seriamente dañado. Además, las alternativas tradicionales de reuso también carecen de soluciones apropiadas para reusar componentes COTS y el conocimiento adquirido en cada proceso de selección. Esta carencia de propuestas es un problema muy serio que incrementa los riesgos de los proyectos de selección de COTS, además de hacerlos ineficientes y altamente costosos. Esta disertación presenta el método GOThIC (Goal- Oriented Taxonomy and reuse Infrastructure Construction) enfocado a la construcción de infraestructuras de reuso para facilitar la búsqueda y reuso de componentes COTS. El método está basado en el uso de objetivos para construir taxonomías abstractas, bien fundamentadas y estables para lidiar con las características del mercado de COTS. Los nodos de las taxonomías son caracterizados por objetivos, sus relaciones son declaradas como dependencias y varios artefactos son construidos y gestionados para promover la reusabilidad y lidiar con la evolución constante.El método GOThIC ha sido elaborado a través de un proceso iterativo de investigación-acción para identificar los retos reales relacionados con el proceso de búsqueda de COTS. Posteriormente, las soluciones posibles fueron evaluadas e implementadas en varios casos de estudio en el ámbito industrial y académico en diversos dominios. Los resultados más relevantes fueron registrados y articulados en el método GOThIC. La evaluación industrial preliminar del método se ha llevado a cabo en algunas compañías en Noruega. / The process of building software systems by assembling and integrating pre-packaged solutions in the form of Commercial-Off-The-Shelf (COTS) software components has become a strategic need in a wide variety of application areas. In general, COTS components are software components that provide a specific functionality, available in the market to be purchased, interfaced and integrated into other software systems. The potential benefits of this technology are mainly its reduced costs and shorter development time, while maintaining the quality. Nevertheless, many challenges ranging form technical to legal issues must be faced for adapting the traditional software engineering activities in order to exploit these benefits.Nowadays there is an increasingly huge marketplace of COTS components; therefore, one of the most critical activities in COTS-based development is the selection of the components to be integrated into the system under development. Selection is basically composed of two main processes, namely: searching of candidates from the marketplace and their evaluation with respect to the system requirements. Unfortunately, most of the different existing methods for COTS selection focus their efforts on evaluation, letting aside the problem of searching components in the marketplace. Searching candidate COTS is not an easy task, having to cope with some challenging marketplace characteristics related to its widespread, evolvable and growing nature; and the lack of available and well-suited information to obtain a quality-assured search. Indeed, traditional reuse approaches also lack of appropriate solutions to reuse COTS components and the knowledge gained in each selection process. This lack of proposals is a serious drawback that makes the whole selection process highly risky, and often expensive and inefficient. This dissertation introduces the GOThIC (Goal- Oriented Taxonomy and reuse Infrastructure Construction) method aimed at building a domain reuse infrastructure for facilitating COTS components searching and reuse. It is based on goal-oriented approaches for building abstract, well-founded and stable taxonomies capable of dealing with the COTS marketplace characteristics. Thus, the nodes of these taxonomies are characterized by means of goals, their relationships declared as dependencies among them and several artifacts are constructed and managed for reusability and evolution purposes. The GOThIC method has been elaborated following an iterative process based on action research premises to identify the actual challenges related to COTS components searching. Then, possible solutions were envisaged and implemented by several industrial and academic case studies in different domains. Successful results were recorded to articulate the synergic GOThIC method solution, followed by its preliminary industrial evaluation in some Norwegian companies.
17

A systems engineering approach to the design of a COTS management system

Basil, Daniel L. 16 December 2009 (has links)
This project applies the management systems engineering methodology to the design and development of a management tool to be used in managing change of the Commercial-Off-The-Shelf [COTS] software, firmware, and hardware utilized within the Mapping Branch of the National Imagery and Mapping Agency [NIMA] (formerly known as the Defense Mapping Agency [DMA J). The management tool is used to support the management process overlaying the work process for changing COTS products. By using the management systems engineering methodology to understand how COTS products are changed, the functional requirements for a management tool can be derived in a clear and concise manner. Concurrently, the systems approach is applied in the development of the management tool, referred to as the COTS Management System. The COTS Management System is identified as required by NIMA due to the increasing number of COTS products being used within the Digital Production System [DPS]. The DPS is NIMA's conglomeration of segmented computer systems combined to provide the tools and functionality necessary to produce the myriad of mapping, charting, and geodesic products in both hard-copy and digital format. NIMA also desires to implement the COTS Management System in an effort to achieve the Software Engineering Institutes [SEI] Capability Maturity Model [CMM] Level 3. / Master of Science
18

Exploring true random number generators Build on commercial-off-the-shelve Components / Sanna slumptalsgeneratorer med lättillgängliga komponenter

Mörk, Linnéa January 2023 (has links)
Generating random numbers can be accomplished through various methods, with the primary distinction lying between pseudo-random number generators (PRNGs), which are commonly used for applications that require a large amount of random data, and true random number generators (TRNGs), which are commonly used for applications that need security and unpredictability. This thesis explores the feasibility of harnessing frequency variations in the electrical grid as a source of entropy for a TRNG. By employing an iterative approach, the study has substantiated the likelihood that frequency fluctuations can serve as a reliable source of ran-domness for a TRNG. This assertion is supported by statistical testing using the comprehensive RNG testing suite known as DieHarder, where the final implementation of the TRNG yielded favourable outcomes. Nevertheless, it is worth noting that the artefact exhibited weaker resultson three specific tests within the suite, which can likely be attributed to a limited amount of generated data. Despite these limitations, the findings are undeniably promising, and futurere search endeavours should focus primarily on enhancing the generation speed of the TRNG. By doing so, it is anticipated that improved performance on the DieHarder suite and similar RNG testing suites can be achieved. / Generering av slumptal kan åstadkommas mev hjälp av flera olika metoder. De två stora grupperna är pseudo-slumptalsgeneratorer (PRNG:er), som vanligtvis används för applikationer som kräver en stor mängd slumpmässiga data, och sanna slumptalsgeneratorer (TRNG:er), som ofta används för applikationer som behöver säkerhet och oförutsägbarhet. Detta examensarbete undersöker möjligheten att utnyttja frekvensvariationer i det elektriska nätetverket som en källa till entropi för en TRNG. Genom att använda ett iterativt tillvägagångssätt har studien underbyggt sannolikheten att frekvensfluktuationer kan fungera som en pålitlig källa till slumpmässighet för en TRNG. Detta påstående stöds av statistiska tester med den omfattande RNG-testsviten känd som DieHarder, där den slutliga implementeringen av TRNG:n gav gynnsamma resultat. Det är värt att notera att artefacten visade svagare resultat på tre specifika tester inom sviten, vilket sannolikt kan tillskrivas en begränsad mängd genererad data. Trots dessa begränsningar är resultaten onekligen lovande, och framtida forskningsansträngningar bör främst fokusera på att öka generationshastigheten för generatorn. Genom att göra det förväntas det att bättre resultat från DieHarder och liknande RNG-testsviter kan uppnås.
19

UM MÉTODO PARA SELEÇÃO DE SOFTWARE NA ENGENHARIA DE REQUISITOS / A METHOD FOR SELECTION OF SOFTWARE IN SOFTWARE ENGINEERING REQUIREMENTS

CANTANHÊDE FILHO, Paulino Almeida 14 March 2005 (has links)
Made available in DSpace on 2016-08-17T14:52:57Z (GMT). No. of bitstreams: 1 Paulino de Almeida Cantanhede Filho.pdf: 1682767 bytes, checksum: a5fce1801fd45fddf7e98305e0e9b053 (MD5) Previous issue date: 2005-03-14 / Guidelines for evaluation and selection of COTS (Commercial-Off-The-Shelf) products. Comes a methodology for the Development based on COTS (DBC) in the Requirements Engineering, being approached the evaluation phases and selection of DBC. The method is divided in three phases, that are divided in activities orienting by actions that seek to the quality of the information for a socket of decision in an automated and oriented way for defined evaluation criteria during the Requirements Engineering. This approach divide the requirements in three levels: Fundamental, Contractual and Desirable. The functional and no-functional requirements are treated in an equalitarian way. / Este trabalho apresenta diretrizes para avaliação e seleção de produtos COTS (Commercial- Off-The-Shelf). Apresenta-se uma metodologia para o Desenvolvimento Baseado em COTS (DBC) na Engenharia de Requisitos, abordando-se as fases de avaliação e seleção do DBC. O método está dividido em três fases, que por sua vez estão divididas em atividades direcionadas por ações que visam à qualidade das informações para uma tomada de decisão de forma automatizada e orientada por critérios de avaliação definidos durante a Engenharia de Requisitos. Esta abordagem divide os requisitos em três níveis, são eles: Fundamental, Contratual e Desejável. Os requisitos funcionais e não-funcionais são tratados de forma igualitária.
20

Architectural metrics and evaluation for component based software systems

Bhattacharya, Sutirth 21 April 2015 (has links)
Component based software engineering has been perceived to have immense reuse potential. This area has evoked wide interest and has led to considerable investment in research and development efforts. Most of these investigations have explored internal characteristics of software components such as correctness, reliability, modularity, interoperability, understandability, maintainability, readability, portability and generality for promoting reuse. But experience over the past decade and a half has demonstrated that the usefulness of a component depends as much on the context into which it fits as it does on the internal characteristics of the component. Software architecture descriptions that take into account the requirements of the domain can be used to serve as this context. While the Perry, Wolf definition of software architecture has been widely acknowledged, a number of architectural description languages (ADL) have emerged that aim to capture various facets of a software, using varying degrees of formalism. There is currently no agreement towards a standard approach for documenting software architectures which would help define the vocabulary for architectural semantics. In spite of lack of any specification standards for components, Software Product Lines (SPL) and Commercial Off The Shelf (COTS) components do provide a rich supporting base for creating software architectures and promise significant improvements in the quality of software configurations that can be composed from pre-built components. However, further research is needed for evaluation of architectural merits of such component based configurations. In this research, we identify the key aspects of software that need to be specified to enable useful analysis at an architectural level. We also propose a set of metrics that enable objective evaluation of reusability potential. Architectural research has established that software architectural styles provide a way for achieving a desired coherence for component-based architectures. Different architectural styles enforce different quality attributes for a system. Thus, if the architectural style of an emergent system could be predicted, a person playing the role of a system integrator could make necessary changes to ensure that the quality attributes dictated by the system requirements were satisfied before the actual system is built and deployed, thus somewhat mitigating project risks. As part of this research, we propose a model for predicting architectural styles based on use cases that need to be satisfied by a system configuration and demonstrate how our approach can be used to determine stylistic conformance. We also propose objective methods for assessing architectural divergence, erosion and drift during system evolution and maintenance. / text

Page generated in 0.1277 seconds