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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.
1

UCAV : en potentiell luftförsvarare?

Lindström, Martin January 2012 (has links)
Obemannade flygfarkoster, så kallade UAV, har länge används för militära ändamål. Dessa ändamål har främst varit underrättelseinhämtning i form av spaning för att ge markförband bättre beslutsunderlag. De används idag i konflikter som den i Afghanistan där de relativt obehindrade kan operera i luften utan att motståndaren kan påverka dem.Anledningen till denna frihet beror på den kontroll av luftrummet som uppnåtts genom så kallade luftförsvarsoperationer. Dessa operationer syftar till att skapa den kontroll av ett luftrum som en part vill ha eller anses sig behöva för att kunna genomföra mark- eller sjöoperationer. Dessa är indelade i olika uppdragstyper som ställer olika krav på flygplattformen beroende på uppdrag, det kan till exempel vara attack- eller jaktuppdrag. Dessa skall kunna genomföras när motståndaren fortfarande har möjlighet till att verka i luftarenan, antingen från marken eller luften, beroende på vart kontrollen vill nås rent geografiskt.Syftet med arbetet var att undersöka om UCAV skulle lämpa sig i luftförsvarsoperationer där det finns motståndare som kan påverka dem. Resultatet som kom fram är att UCAV, i det utförande som de finns i idag, endast är lämpliga till att genomföra luftförsvarattack inom ramen för luftförsvarsoperationer. Författaren kom också fram till att framtidens UCAV även kommer vara lämpliga till att genomföra SEAD eftersom de då kommer vara mer signaturanpassade, ha högre topphastighet samt kunna bära fler och tyngre vapen. Däremot visade det sig att UCAV vare sig är lämplig eller kommer vara lämplig för genomförande av uppdragen som verkar inom jaktfunktionen. Detta, främst på grund av att de inte har rätt förmågor, men även avsaknaden av en pilot på plats är en nackdel då det skapar sämre förutsättningar till att ta sig igenom beslutscykeln, tillika OODA-loopen.
2

Avaliação do efeito de acoplamento eletromagnético sobre a estimação de ângulos de incidência de ondas planas / Evaluation of the electromagnetic coupling effect on the estimation of incidents angles of plane waves

Coelho, André Almeida Souza 19 February 2018 (has links)
Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2018-05-29T12:47:57Z No. of bitstreams: 2 Dissertação - André Almeida Souza Coelho - 2018.pdf: 12771064 bytes, checksum: b6418151bb082eeffbdb1692392e483e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-05-29T12:49:33Z (GMT) No. of bitstreams: 2 Dissertação - André Almeida Souza Coelho - 2018.pdf: 12771064 bytes, checksum: b6418151bb082eeffbdb1692392e483e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-29T12:49:33Z (GMT). No. of bitstreams: 2 Dissertação - André Almeida Souza Coelho - 2018.pdf: 12771064 bytes, checksum: b6418151bb082eeffbdb1692392e483e (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-19 / This work deals with the problem of estimation of incident angles (DOA) of plane waves on a linear array of sensors taking into account the mutual coupling between the sensors. MUSIC and SEAD methods are analyzed with and without coupling, in the cases of correlated and uncorrelated signals, and a compensation method is applied to minimize estimation errors. Several results are obtained and the statistical performance of MUSIC and SEAD is evaluated, proposing an application scenario for SEAD when under the influence of mutual coupling between the sensors. / Este trabalho aborda o problema de estimação de ângulos de incidência (DOA) de ondas planas sobre um arranjo linear de sensores levando em consideração o acoplamento mútuo entre os sensores. São analisados os métodos MUSIC e SEAD com e sem acoplamento, nos casos de sinais descorrelacionados e correlacionados, e aplicado um método de compensação para minimizar os erros de estimação. Diversos resultados são obtidos e o desempenho estatístico do MUSIC e SEAD é avaliado, propondo um cenário de aplicação para o SEAD quando sob a influência do acoplamento mútuo entre os sensores.
3

Vídeo digital : análise de sua aplicação como objeto de aprendizagem

Souza, Adriano Dias de January 2012 (has links)
O vídeo digital vem se inserindo gradativamente no contexto da educação presencial e a distância. Neste sentido, a presente pesquisa objetiva analisar, dentre as propostas contempladas nos 15 editais propostos pela SEAD/UFRGS, e que cobrem o período de 2001 a 2011, aquelas que tenham este tipo de Objeto de Aprendizagem na sua concepção, bem como seus espaços de armazenamento e disseminação, com vistas a verificar sua funcionalidade. O referencial teórico contextualiza os temas: imagem digital; vídeo e vídeo digital – evolução, armazenamento e disseminação; vídeo educativo; repositórios de vídeo; Objetos de Aprendizagem; além de abordar a SEAD/UFRGS, enquanto órgão responsável pelos editais. O estudo tem caráter exploratório com abordagem quantitativa e qualitativa utilizando questionário para a coleta de dados. Os sujeitos da pesquisa detêm-se em quatro projetos contemplados pelos editais da SEAD/UFRGS. Levanta dados sobre aspectos da produção, da disponibilização e do uso do vídeo criado/desenvolvido. Busca entender como se deu a participação da SEAD no processo de produção, armazenamento e disponibilização. Como resultado estabelece que o uso do vídeo digital ainda não é uma prática constante entre os docentes, quer seja em sala de aula ou em ambientes de Educação a Distância, mas verifica que o professor considera este um recurso importante no ensino; que o docente não tem, ainda, o hábito de fazer trabalhos colaborativos neste meio, mas entende como importante produzir desta forma. Sinaliza que os respondentes não fazem parte de redes ou comunidades virtuais relacionadas ao produto vídeo digital; que consideram importante ter seus vídeos disponíveis em Repositórios Institucionais, mas, no entanto, não tem nenhum canal próprio nos repositórios de vídeo disponíveis. Conclui, pelos dados coletados, que aqueles que já tiveram alguma experiência com o uso do vídeo continuarão a investir neste tipo de material institucional. Relaciona as contribuições que o estudo traz às diferentes áreas no contexto das universidades. Sugere novos estudos, aprofundando as análises, abordando outros temas ligados ao uso do vídeo, em especial voltado à disseminação da produção científica. / Digital video has been gradually introduced in the context of both distance and presence education. Thus this research aims to analyze, among the proposals covered in 15 invitations to bid offered by SEAD/UFRGS, and covering the period 2001 to 2011, those who have this type of learning object in its conceiving, as well as spaces of storage and dissemination, in order to verify its functionality. The theoretical framework contextualizes the themes: digital image, video and digital video – evolution, storage and distribution; educational video; video repositories; learning objects; apart from discussing SEAD/UFRGS as the body responsible for the invitation to bid. The study has an exploratory nature based in quantitative and qualitative approach, by using a questionnaire to collect data. Its subjects are four projects covered by the SEAD/UFRGS’s invitations to bid. It collects data on aspects of production, availability and use of the created or developed videos. It seeks to understand how was the SEAD participation in the production, storage and release process. As a result states that the use of digital video is not yet an established practice among teachers, whether in the classroom or in distance learning environments, but remarks that the teacher considers it an important resource in teaching; also that the he does not has the habit of doing collaborative work in this medium, but understands how important is to produce this way. It indicates that the respondents are not part of networks or virtual communities related to digital video products; as well that they consider important to have their videos available in institutional repositories, although they have no dedicated channel video available in the repositories. It concludes, based on the data collected, that those who have already had some experience with the use of video will continue to invest in this type of institutional material. It lists the contributions that the study brings to the different areas in the academic field. It suggests further studies to deepen the review by addressing other subjects related to the use of video, particularly focused on the dissemination of scientific production.
4

Vídeo digital : análise de sua aplicação como objeto de aprendizagem

Souza, Adriano Dias de January 2012 (has links)
O vídeo digital vem se inserindo gradativamente no contexto da educação presencial e a distância. Neste sentido, a presente pesquisa objetiva analisar, dentre as propostas contempladas nos 15 editais propostos pela SEAD/UFRGS, e que cobrem o período de 2001 a 2011, aquelas que tenham este tipo de Objeto de Aprendizagem na sua concepção, bem como seus espaços de armazenamento e disseminação, com vistas a verificar sua funcionalidade. O referencial teórico contextualiza os temas: imagem digital; vídeo e vídeo digital – evolução, armazenamento e disseminação; vídeo educativo; repositórios de vídeo; Objetos de Aprendizagem; além de abordar a SEAD/UFRGS, enquanto órgão responsável pelos editais. O estudo tem caráter exploratório com abordagem quantitativa e qualitativa utilizando questionário para a coleta de dados. Os sujeitos da pesquisa detêm-se em quatro projetos contemplados pelos editais da SEAD/UFRGS. Levanta dados sobre aspectos da produção, da disponibilização e do uso do vídeo criado/desenvolvido. Busca entender como se deu a participação da SEAD no processo de produção, armazenamento e disponibilização. Como resultado estabelece que o uso do vídeo digital ainda não é uma prática constante entre os docentes, quer seja em sala de aula ou em ambientes de Educação a Distância, mas verifica que o professor considera este um recurso importante no ensino; que o docente não tem, ainda, o hábito de fazer trabalhos colaborativos neste meio, mas entende como importante produzir desta forma. Sinaliza que os respondentes não fazem parte de redes ou comunidades virtuais relacionadas ao produto vídeo digital; que consideram importante ter seus vídeos disponíveis em Repositórios Institucionais, mas, no entanto, não tem nenhum canal próprio nos repositórios de vídeo disponíveis. Conclui, pelos dados coletados, que aqueles que já tiveram alguma experiência com o uso do vídeo continuarão a investir neste tipo de material institucional. Relaciona as contribuições que o estudo traz às diferentes áreas no contexto das universidades. Sugere novos estudos, aprofundando as análises, abordando outros temas ligados ao uso do vídeo, em especial voltado à disseminação da produção científica. / Digital video has been gradually introduced in the context of both distance and presence education. Thus this research aims to analyze, among the proposals covered in 15 invitations to bid offered by SEAD/UFRGS, and covering the period 2001 to 2011, those who have this type of learning object in its conceiving, as well as spaces of storage and dissemination, in order to verify its functionality. The theoretical framework contextualizes the themes: digital image, video and digital video – evolution, storage and distribution; educational video; video repositories; learning objects; apart from discussing SEAD/UFRGS as the body responsible for the invitation to bid. The study has an exploratory nature based in quantitative and qualitative approach, by using a questionnaire to collect data. Its subjects are four projects covered by the SEAD/UFRGS’s invitations to bid. It collects data on aspects of production, availability and use of the created or developed videos. It seeks to understand how was the SEAD participation in the production, storage and release process. As a result states that the use of digital video is not yet an established practice among teachers, whether in the classroom or in distance learning environments, but remarks that the teacher considers it an important resource in teaching; also that the he does not has the habit of doing collaborative work in this medium, but understands how important is to produce this way. It indicates that the respondents are not part of networks or virtual communities related to digital video products; as well that they consider important to have their videos available in institutional repositories, although they have no dedicated channel video available in the repositories. It concludes, based on the data collected, that those who have already had some experience with the use of video will continue to invest in this type of institutional material. It lists the contributions that the study brings to the different areas in the academic field. It suggests further studies to deepen the review by addressing other subjects related to the use of video, particularly focused on the dissemination of scientific production.
5

Vídeo digital : análise de sua aplicação como objeto de aprendizagem

Souza, Adriano Dias de January 2012 (has links)
O vídeo digital vem se inserindo gradativamente no contexto da educação presencial e a distância. Neste sentido, a presente pesquisa objetiva analisar, dentre as propostas contempladas nos 15 editais propostos pela SEAD/UFRGS, e que cobrem o período de 2001 a 2011, aquelas que tenham este tipo de Objeto de Aprendizagem na sua concepção, bem como seus espaços de armazenamento e disseminação, com vistas a verificar sua funcionalidade. O referencial teórico contextualiza os temas: imagem digital; vídeo e vídeo digital – evolução, armazenamento e disseminação; vídeo educativo; repositórios de vídeo; Objetos de Aprendizagem; além de abordar a SEAD/UFRGS, enquanto órgão responsável pelos editais. O estudo tem caráter exploratório com abordagem quantitativa e qualitativa utilizando questionário para a coleta de dados. Os sujeitos da pesquisa detêm-se em quatro projetos contemplados pelos editais da SEAD/UFRGS. Levanta dados sobre aspectos da produção, da disponibilização e do uso do vídeo criado/desenvolvido. Busca entender como se deu a participação da SEAD no processo de produção, armazenamento e disponibilização. Como resultado estabelece que o uso do vídeo digital ainda não é uma prática constante entre os docentes, quer seja em sala de aula ou em ambientes de Educação a Distância, mas verifica que o professor considera este um recurso importante no ensino; que o docente não tem, ainda, o hábito de fazer trabalhos colaborativos neste meio, mas entende como importante produzir desta forma. Sinaliza que os respondentes não fazem parte de redes ou comunidades virtuais relacionadas ao produto vídeo digital; que consideram importante ter seus vídeos disponíveis em Repositórios Institucionais, mas, no entanto, não tem nenhum canal próprio nos repositórios de vídeo disponíveis. Conclui, pelos dados coletados, que aqueles que já tiveram alguma experiência com o uso do vídeo continuarão a investir neste tipo de material institucional. Relaciona as contribuições que o estudo traz às diferentes áreas no contexto das universidades. Sugere novos estudos, aprofundando as análises, abordando outros temas ligados ao uso do vídeo, em especial voltado à disseminação da produção científica. / Digital video has been gradually introduced in the context of both distance and presence education. Thus this research aims to analyze, among the proposals covered in 15 invitations to bid offered by SEAD/UFRGS, and covering the period 2001 to 2011, those who have this type of learning object in its conceiving, as well as spaces of storage and dissemination, in order to verify its functionality. The theoretical framework contextualizes the themes: digital image, video and digital video – evolution, storage and distribution; educational video; video repositories; learning objects; apart from discussing SEAD/UFRGS as the body responsible for the invitation to bid. The study has an exploratory nature based in quantitative and qualitative approach, by using a questionnaire to collect data. Its subjects are four projects covered by the SEAD/UFRGS’s invitations to bid. It collects data on aspects of production, availability and use of the created or developed videos. It seeks to understand how was the SEAD participation in the production, storage and release process. As a result states that the use of digital video is not yet an established practice among teachers, whether in the classroom or in distance learning environments, but remarks that the teacher considers it an important resource in teaching; also that the he does not has the habit of doing collaborative work in this medium, but understands how important is to produce this way. It indicates that the respondents are not part of networks or virtual communities related to digital video products; as well that they consider important to have their videos available in institutional repositories, although they have no dedicated channel video available in the repositories. It concludes, based on the data collected, that those who have already had some experience with the use of video will continue to invest in this type of institutional material. It lists the contributions that the study brings to the different areas in the academic field. It suggests further studies to deepen the review by addressing other subjects related to the use of video, particularly focused on the dissemination of scientific production.
6

Sow SEAD, Reap DEAD, Secure Air Superiority : Russia's failures to establish air superiority in Ukraine - En kvalitativ textanalys om luftkriget i kriget mellan Ryssland och Ukraina.

Helenius, Jim January 2024 (has links)
Why has Russia failed to establish air superiority over Ukraine despite its superiority in personnel and resources within the air force compared to Ukraine? Previous research mentions the failed SEAD/DEAD operations as a contributing factor, yet these studies have focused on the strategic and operational levels. This study examines the factors contributing to the failed SEAD/DEAD operations at the tactical level. This is conducted through a qualitative text analysis using a theoretical framework derived from Warden and Pape, as well as a study by Bucki. The factors examined in the operations include; high-technology combat aircraft and missiles, the ability to conduct low-altitude flying, the position of airbases relative to the operational area, disabling sensors, intelligence, and electronic warfare capabilities. The results indicate that Russia did not achieve any of these factors except for positioning. However, this did not prove advantageous as the ability to conduct longer low-altitude flights was limited.
7

Redução da complexidade computacional do método de estimação de ângulos de incidência através da diferença entre os valores singulares da matriz de covariância espacial / Computacional complexity reduction of direction-of-arrival estimation method through the difference between singular values from spatial covariance matrix

SILVA, Hugo Vinícius Leão e 13 March 2009 (has links)
Made available in DSpace on 2014-07-29T15:08:20Z (GMT). No. of bitstreams: 1 Dissertacao_Hugo_Silva.pdf: 1463961 bytes, checksum: 3a6b5b3e5e7db58659b1bb58d6d4cd66 (MD5) Previous issue date: 2009-03-13 / This work is concerned with the estimation of Direction-Of-Arrival (DOA) angles of plane waves impinging on a sensor array. Among all methods of estimation found in litera-ture, MODEX (MODE with eXtra roots) outstands for its performance and computational complexity. However, recently, a method called SEAD (SEArch of Direction by differential spectrum) was proposed. It has shown better estimation performance against noise than MODEX has. However, its computational complexity is prohibitive for real-time applications. In order to reduce it s computational complexity, a new estimate selection procedure on SEAD is proposed, that yields to significantly less candidate angles than before. Additionally, the introduction of iterative refinements on estimates has allowed improving resolution as well as complexity reduction / Este trabalho aborda o problema de estimação de ângulos de incidência (DOA) de ondas planas sobre um arranjo de sensores. Dentre os vários métodos encontrados na literatu-ra, o método MODEX (MODE with eXtra roots) se destaca por seu desempenho e complexi-dade computacional. Recentemente, foi proposto o método SEAD (SEArch of Direction by differential spectrum), que apresenta desempenho de estimação mais robusto que o MODEX aos efeitos do ruído, contudo, possui complexidade computacional proibitiva para aplicações de tempo-real. Na busca por reduzir esta complexidade computacional, este trabalho apresenta uma nova proposta de seleção de estimativas para o SEAD que gera uma quantidade signifi-cativamente menor de ângulos candidatos. Adicionalmente, a inserção de um processo iterati-vo de refinamento de soluções permitiu que a resolução do estimador fosse aprimorada em relação àquela inicialmente ajustada, além de reduzir a complexidade computacional da sele-ção
8

Eagles, ravens, and other birds of prey: a history of USAF Suppression of Enemy Air Defense doctrine, 1973-1991

Young, James L., Jr. January 1900 (has links)
Doctor of Philosophy / Department of History / Donald J. Mrozek / During the Cold War, the United States’ foreign policy relied heavily on its ability to project military power. More often than not, the central component of force projection rested on the United States military’s effectiveness in employing air power both by establishing air superiority and through accurate delivery of ordnance. As the primary service tasked with conducting aerial warfare, the United States Air Force (USAF) was expected to maintain this capability either to achieve deterrence or, when necessary, to military action. In January 1973, the USAF seemed incapable of performing the latter task due to the North Vietnamese Integrated Air Defense System’s (NV-IAD’s) effectiveness in Operation Rolling Thunder and its successor, Operation Linebacker. Eighteen years later, Air Force aircraft spearheaded the Coalition’s air attack on the Iraqi Integrated Air Defense System (I-IADS) in January 1991. Considered by many to be the most effective air defense system outside the Soviet Union’s, the I-IADS was expected to exact heavy casualties from the allied forces. Instead, in less than twenty days, the USAF’s dominance was so complete that politicians, analysts and military historians quickly proclaimed a “Revolution in Military Affairs” (RMA). The majority of the current historiography credits advances in precision-guided munitions (PGMs), airframes, and computer technology as the impetus for the RMA. Others have claimed that the USAF’s training methodology and construction of advanced training sites such as the Red Flag complex at Nellis Air Force Base were the primary drivers for the Air Force’s success. While acknowledging the role all of these factors played, this dissertation also demonstrates the key role played by the development of Suppression of Enemy Air Defense (SEAD) doctrine from January 1973 through August 1991. In the aftermath of the American war in Vietnam, the Air Force considered defense suppression a tactical task that was secondary to the primary mission of putting ordnance on target. At the end of Desert Storm, proponents of the Air Force’s SEAD doctrine had convincing evidence that an enemy IADS was not just an ancillary weapons array, but functioned a critical national system just like manufacturing, government, or the people’s will. The process by which this viewpoint changed had effects on the development of the United States Air Force’s Cold War conventional capability in general, and the development of training methods, electronic warfare platforms, and modern airframes specifically.
9

Högrörlig luftvärnsradar : Ny förmåga som bidrar till militär nytta?

Larsson, Linus January 2024 (has links)
Detta arbete syftar till att utforska de möjligheter som finns med ett högrörligt luftvärnsradarsystem inom Försvarsmakten. Detta görs med fokus på systemets förmåga att undgå bekämpning och huruvida systemets rörlighet kan bidra med militär nytta. Teorin om militär nytta är avgränsad till enstaka indikatorer för militär effektivitet i detta arbete. För att genomföra denna studie har tre olika scenarier konstruerats där radaren Saab Giraffe 1X utsätts för bekämpning av olika robotar. Därefter beräknas radarsystemets förutsättningar att undgå bekämpning med hjälp av en rörlighetskoefficient. Slutligen genomförs en SWOT-analys för att identifiera faktorer som påverkar de valda indikatorerna för militär nytta i de olika scenarierna. Analysen visar att radarsystemet kan undgå bekämpning i samtliga scenarier med hjälp av sin rörlighet. Slutsatsen är följaktligen att radarsystemet kan nyttja sin rörlighet för att bidra med militär nytta genom att dels nyttja frekventa omgrupperingar på ett planerat sätt samt genom att omgruppera då en inkommande robot upptäcks av radaren.
10

United States Air Force Defense Suppression Doctrine, 1968-1972

Young, James L. Jr. January 1900 (has links)
Master of Arts / Department of History / Donald J. Mrozek / On March 30, 1972 the Democratic Republic of Vietnam (DRV) launched a conventional offensive, dubbed the Easter Offensive, against South Vietnam. In response to this act President Richard Nixon ordered the United States Air Force (USAF) and Navy (USN) to resume bombing North Vietnam. For the next nine months, USAF conducted offensive operations against the whole of the DRV in an attempt to accomplish four major objectives. First, USAF units sought to interdict sufficiently the North Vietnamese Army's (NVA's) supply lines to preclude continued conventional operations in South Vietnam. Second, President Nixon had directed the Air Force to inflict sufficient punishment on North Vietnam in order to deter further aggression against its southern neighbor. Third, as implied by the Nixon Doctrine, USAF was to establish convincingly its ability to conduct conventional operations in support of an allied nation during a major conflict. Finally, with the introduction of B-52 bombers in December 1972, the Air Force was to maintain the credibility of manned strategic aircraft as part of American nuclear deterrence policy. Historically, the United States Air Force and many civilian observers have maintained that the United States Air Force succeeded in all four tasks. However, the evidence strongly indicates that the United States Air Force not only failed to achieve all but the interdiction objective during the course of operations against North Vietnam, but that this defeat stemmed from the decision not to develop a comprehensive Suppression of Enemy Air Defense (SEAD) doctrine from 1968 through 1972. In choosing this course of action, USAF's military and civilian leaders guaranteed that American forces would be unable to bring sufficient force to bear to achieve President Nixon's goals. Furthermore, by choosing this course of action and, in addition, refocusing the Air Force on nuclear delivery rather than enhancing USAF's capability to penetrate an integrated air defense (IADS), these same leaders ignored the results of Operation Rolling Thunder. The consequence of this choice, as will be shown in the following pages, was an outcome that had serious implications for the United States' Cold War conventional and nuclear military policy.

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