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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.
41

Proposta de um modelo de programação estruturado a partir das particularidades do fluxo de produção de um sistema de manufatura celular / Proposal of a production programming procedure based on particularities of a cell manufacturing system\'s production flow

Murilo Melhado Baldi 20 October 2017 (has links)
A proposta de um procedimento de programação da produção, estruturado a partir das particularidades do fluxo de produção de um sistema de manufatura celular, descrita neste trabalho, é resultado do processo de investigação da relação do uso de ferramentas computacionais, especialistas em programação da produção, envolvendo práticas de controle de estoque no abastecimento de um sistema de manufatura celular. Deste modo, o conteúdo deste trabalho trata das principais restrições inerentes a relação entre os diferentes parâmetros e variáveis do processo de fabricação deste tipo de sistema, os quais interferem diretamente na eficácia e eficiência de um sistema de programação da produção, além de enfatizar os resultados efetivos que podem ser alcançados com o uso de um software APS, assim como uma lógica de programação, com ênfase na minimização do Lead Time Offsetting. Neste contexto, além do resultado efetivo que este trabalho demonstra, a partir do uso de um sistema de programação da produção em um ambiente de manufatura celular, há, inerentemente, o destaque à relevância do tema de pesquisa, estudado na literatura, devido ao crescente aumento da complexidade dos sistemas produtivos e, consequentemente, da dificuldade de análises mais precisas do impacto que as variáveis de fluxo, como por exemplo, tempos de abastecimento e movimentação, tempos de setup e os respectivos roteiros de fabricação, podem causar no desempenho dos processos no chão de fábrica. Quanto ao método de pesquisa o estudo aborda o tema, quanto à aplicação de um modelo de programação da produção estruturado, com base no escopo da proposta, através de um estudo de caso de uma empresa fornecedora de componentes do setor de automotivo, envolvendo pesquisa de campo com acesso a documentos do processo de fabricação e da estrutura de materiais do mix de produtos relacionados, além do contato direto com os atores do processo de fabricação a partir de reuniões periódicas durante o processo de concepção do procedimento. A partir da construção do modelo de programação, cenários são gerados de modo a comparar a performance dos mesmos em um ambiente produtivo real, sendo realizadas alterações de variáveis no fluxo produtivo, a fim de obter resultados interessantes e satisfatórios, utilizando-se de parâmetros como tamanho de lote e makespan como indicadores de performance. / The proposal of a production programming procedure, built from the particularities of a cellular manufacturing system\'s production flow, described in this work, is the result of a investigation process about the relation of using computational tools, specialized in production programming, involving practices of inventory control in a supply system of a manufacturing cell. Thus, the content of this work deals with the main constraints inherent in the relationship between different parameters and variables of the manufacturing process, regarding this type of production system, that directly interferes in the efficiency of a production scheduling system, emphasizing the effective results that can be achieved through the use of an APS software and programming logic, with emphasis on minimizing Lead Time Offsett. Thereby, in addition to the effective result that this work demonstrates about the use of a production programming system, in a cellular manufacturing environment, we should also emphasize the topic reserchead, and studied, in this work due to the increasing complexity of manufacturing systems and environments as well as the difficulty of more precise analyzes regarding the impact of production flow variables, such as supply and movement times, setup times and the variability offered by manufacturing routes, which can cause underperformance of production processes in a factory. About the research method, this study approaches the subject, regarding the application of a programming model, based on the scope of the initial proposal, through a case study of a company that supplies automotive componentes, in the brazilian automobile sector. This study encompasses field research with access to documents of the manufacturing process as well as the bill of materials of related products, also, direct contact with the actors of the manufacturing process through periodic meetings during the procedure design process. Regarding the results achieved by this work, it is important to highlight the creation of different cenarios and comparisons that were made, regarding the use of different parameters and variables, such as makespan and lot sizing, so that the optimal experience could be achived, through the use of a customized programming model developed, exclusively, for this research.
42

[en] ADVANCED PLANNING SYSTEMS (APS) ANALYSIS: CONCEPTION AND EVALUATION / [pt] ANÁLISE DE SISTEMAS DE PLANEJAMENTO AVANÇADO (APS): CONCEITUAÇÃO E AVALIAÇÃO

GISELE GOMES AGUILAR 19 January 2005 (has links)
[pt] O presente trabalho tem como objetivo principal apresentar uma análise sobre as funcionalidades existentes nos aplicativos de planejamento avançado, os chamados Advanced Planning Systems (APS) e os ganhos obtidos pelas empresas com a implementação desses aplicativos. Para realizar tal análise foi feita uma revisão bibliográfica visando estudar e apresentar os conceitos dos aplicativos para o gerenciamento da cadeia de suprimentos e dos aplicativos de planejamento avançado, bem como apresentar o mercado atual para esses aplicativos. O sistema APO (Advanced Planner and Optimizer), da empresa alemã SAP, foi o escolhido para a exemplificação de aplicativos de planejamento avançado. Por meio da realização de entrevistas em duas empresas que utilizam o APO e com o auxílio de um questionário semi-estruturado foi possível uma análise de como essas empresas estão utilizando esse sistema. Foi possível observar o que levou as empresas a implementarem um aplicativo de planejamento avançado, as mudanças ocorridas nos diversos processos e os ganhos obtidos com a implementação. / [en] The purpose of this document is presenting the existing functionalities of the advanced planning software, the so called Advanced Planning Systems (APS) and the benefits obtained by the companies with the implementation of these systems. In order to accomplish such analysis, a bibliographic research was made to study and present the concepts of the supply chain management applications and advanced planning systems, as well as present the current market for these applications. The APO (Advanced Planner and Optimizer) system of the German company SAP was chosen for the exemplification of the advanced planning systems. Based on interviews performed at two companies, which made use of the APO and with the aid of a semi-structured form it was possible to understand how these companies are utilizing this system. It was also possible to observe what led the companies to implement an advanced planning system, the changes that occurred in the various processes and the benefits obtained with the implementation.
43

[en] ADVANCED PLANNING SYSTEM APPLIED TO INVENTORY ANALYSIS: AN ACTION RESEARCH IN A FUEL DISTRIBUTION COMPANY IN BRAZIL / [pt] SISTEMA DE PLANEJAMENTO AVANÇADO APLICADO A ANÁLISE DE INVENTÁRIO: UMA PESQUISA AÇÃO EM UMA DISTRIBUIDORA DE COMBUSTÍVEIS NO BRASIL

EDSON SOBREIRA DE CARVALHO NETO 08 February 2019 (has links)
[pt] Esta dissertação se propõe a fazer uma análise dos níveis de inventário de uma empresa distribuidora de combustíveis brasileira. Trata da busca contínua pelo estado-da-arte em termos de modelagem logística e como lidar com os diversos trade-offs existentes na cadeia de suprimentos. O objetivo principal é apresentar como este modelo foi criado utilizando um Sistema de Planejamento Avançado, como isso ajudou no dimensionamento dos estoques de segurança e, finalmente, que ações foram necessárias para garantir um processo de melhoria contínua que agregasse valor à companhia pudesse ser desenvolvido. Trata ainda sobre o ganho de importância dos softwares de gerenciamento da cadeia de suprimentos e como o uso destas tecnologias pode ser útil no tratamento de problemas relacionados a análise de inventário utilizando uma abordagem de pesquisa-ação. Este trabalho trouxe percepções valiosas para o negócio, como a realocação dos estoques de segurança a partir dos tempos de transporte e perfil da demanda, a economia potencial que uma previsão de vendas mais assertiva pode trazer para a companhia e ainda como os investimentos em infraestrutura podem ser direcionados pela compreensão da dinâmica do inventário. A nova solução proposta implicou em uma redução de 17,8 porcento nos níveis de inventário. / [en] This dissertation addresses the initiatives in the inventory analysis of a fuel distribution company in Brazil. It tells about the continuous search for the stateof-art in terms of logistics modeling and how to deal with several of trade-offs existing in the supply chain. The main objective is to present how this model was created using an Advanced Planning System, how it helped to dimension the safety stocks and finally, what actions need to be taken in order to ensure that a ripening process that adds value to the company can be developed. It still addresses the growing importance of Supply Chain Management software and how the use of these technologies can be useful to tackle inventory analysis problems using an action research approach. This work provided powerful insights like the reallocation of safety stocks according to the transportation times and demand profiles, the potential economy that a more accurate demand forecast can bring to the company and even how investments in infrastructure can be driven by the new comprehension of the inventory dynamics. The new solution proposed implies a reduction of 17.8 percent in the inventory levels.
44

Proposta de um modelo de programação estruturado a partir das particularidades do fluxo de produção de um sistema de manufatura celular / Proposal of a production programming procedure based on particularities of a cell manufacturing system\'s production flow

Baldi, Murilo Melhado 20 October 2017 (has links)
A proposta de um procedimento de programação da produção, estruturado a partir das particularidades do fluxo de produção de um sistema de manufatura celular, descrita neste trabalho, é resultado do processo de investigação da relação do uso de ferramentas computacionais, especialistas em programação da produção, envolvendo práticas de controle de estoque no abastecimento de um sistema de manufatura celular. Deste modo, o conteúdo deste trabalho trata das principais restrições inerentes a relação entre os diferentes parâmetros e variáveis do processo de fabricação deste tipo de sistema, os quais interferem diretamente na eficácia e eficiência de um sistema de programação da produção, além de enfatizar os resultados efetivos que podem ser alcançados com o uso de um software APS, assim como uma lógica de programação, com ênfase na minimização do Lead Time Offsetting. Neste contexto, além do resultado efetivo que este trabalho demonstra, a partir do uso de um sistema de programação da produção em um ambiente de manufatura celular, há, inerentemente, o destaque à relevância do tema de pesquisa, estudado na literatura, devido ao crescente aumento da complexidade dos sistemas produtivos e, consequentemente, da dificuldade de análises mais precisas do impacto que as variáveis de fluxo, como por exemplo, tempos de abastecimento e movimentação, tempos de setup e os respectivos roteiros de fabricação, podem causar no desempenho dos processos no chão de fábrica. Quanto ao método de pesquisa o estudo aborda o tema, quanto à aplicação de um modelo de programação da produção estruturado, com base no escopo da proposta, através de um estudo de caso de uma empresa fornecedora de componentes do setor de automotivo, envolvendo pesquisa de campo com acesso a documentos do processo de fabricação e da estrutura de materiais do mix de produtos relacionados, além do contato direto com os atores do processo de fabricação a partir de reuniões periódicas durante o processo de concepção do procedimento. A partir da construção do modelo de programação, cenários são gerados de modo a comparar a performance dos mesmos em um ambiente produtivo real, sendo realizadas alterações de variáveis no fluxo produtivo, a fim de obter resultados interessantes e satisfatórios, utilizando-se de parâmetros como tamanho de lote e makespan como indicadores de performance. / The proposal of a production programming procedure, built from the particularities of a cellular manufacturing system\'s production flow, described in this work, is the result of a investigation process about the relation of using computational tools, specialized in production programming, involving practices of inventory control in a supply system of a manufacturing cell. Thus, the content of this work deals with the main constraints inherent in the relationship between different parameters and variables of the manufacturing process, regarding this type of production system, that directly interferes in the efficiency of a production scheduling system, emphasizing the effective results that can be achieved through the use of an APS software and programming logic, with emphasis on minimizing Lead Time Offsett. Thereby, in addition to the effective result that this work demonstrates about the use of a production programming system, in a cellular manufacturing environment, we should also emphasize the topic reserchead, and studied, in this work due to the increasing complexity of manufacturing systems and environments as well as the difficulty of more precise analyzes regarding the impact of production flow variables, such as supply and movement times, setup times and the variability offered by manufacturing routes, which can cause underperformance of production processes in a factory. About the research method, this study approaches the subject, regarding the application of a programming model, based on the scope of the initial proposal, through a case study of a company that supplies automotive componentes, in the brazilian automobile sector. This study encompasses field research with access to documents of the manufacturing process as well as the bill of materials of related products, also, direct contact with the actors of the manufacturing process through periodic meetings during the procedure design process. Regarding the results achieved by this work, it is important to highlight the creation of different cenarios and comparisons that were made, regarding the use of different parameters and variables, such as makespan and lot sizing, so that the optimal experience could be achived, through the use of a customized programming model developed, exclusively, for this research.
45

Effet de projection de pellettes bioxycarbonées sur la qualité de revêtements élaborés par la projection thermique / Effect of dry ice blasting on the quality of coatings produced by thermal spraying

Dong, Shujuan 11 December 2013 (has links)
La technologie de projection plasma atmosphérique (APS) est largement utilisée pour des applications industrielles. Les revêtements élaborés par APS présentent généralement certains défauts. Les travaux effectués dans cette étude ont consisté à étudier et à développer un nouveau moyen pour assurer à la fois un refroidissement efficace au cours de procédé de projection APS et une adaptation des conditions superficielles en vue d’élaborer des revêtements de haute qualité. Ce moyen consiste à la projection de glace carbonique (glace sèche ou dioxyde de carbone solide) en association avec la projection plasma. Des simulations numériques ont été réalisées, qui ont permis de constater que les dimensions de la buse de projection de glace carbonique, la pression du gaz propulsif, et les propriétés des pellets de CO2 influencent sensiblement la vitesse des pellets de CO2. A partir de ces éléments, des dimensions optimales ont été évaluées. Afin d’examiner l’effet de la projection de glace carbonique sur les revêtements réalisés par projection thermique, plusieurs types de matériaux ont été considérés, trois métalliques (acier, CoNiCrAlY et aluminium pur) et trois céramiques (Al2O3, Cr2O3 et ZrO2-Y2O3). Les microstructures des revêtements metalliques réalisés avec projection de glace sèche présentent moins d'oxydes et moins de porosité par rapport à ceux déposés par APS classique. Dans certains cas l’adhérence peut aussi être améliorée. Pour les revêtements céramiques, une réduction de la porosité ainsi qu’une amélioration significative de l’adhérence des revêtements ont été constatés. Pour le dépôt de ZrO2-Y2O3, la résistance aux chocs thermiques a été améliorée en utilisant des paramètres spécifiques. La projection de CO2 peut légèrement déformer la surface des substrats de faible dureté, et nettoyer les pollutions superficielles sur le substrat et conduire à une contrainte de compression plus élevée et à un refroidissement efficace. Il est à noter toutefois qu’un problème de condensation de la vapeur d’eau peut intervenir en cas de refroidissement du substrat trop important. / The technology of atmospheric plasma spraying (APS) is widely used for industrial applications. The coatings produced by APS generally show defects. The work was conducted to investigate and develop a new method to ensure both an effective cooling during the APS process and the adaptation of the surface condition in order to develop high quality coatings. This solution is dry ice (CO2) blasting in combination with thermal spraying. Firstly, numerical simulations were carried out, which revealed that the nozzle size of dry ice blasting, the propellant pressure and the properties of CO2 pellets, significantly affect the velocity of CO2 pellets. From these elements, the optimal dimensions were evaluated. To examine the effects of dry ice blasting on the coatings produced by thermal spraying, several types of materials were considered, three metals (steel, CoNiCrAlY and pure aluminum) and three ceramics (Al2O3, Cr2O3 and ZrO2-Y2O3). The microstructure of metal coatings produced with dry ice blasting show fewer oxides and less porosity compared to those deposited by conventional APS. In some cases the adhesion can be improved. Regarding ceramic coatings, a reduction in porosity and a significant improvement in the coating adhesion were observed. For the deposition of ZrO2-Y2O3, an improvement in thermal shock resistance was achieved using specific parameters. Dry-ice blasting may slightly impact the surface of the substrates with low hardness and could clean the surface pollutions on the substrate and lead to a higher compressive stress and an effective cooling. However, it is noted that the problem of the condensation of water vapor can occur in case of intense cooling of the substrate.
46

Scientific journals go DAISY

Gardner, John A., Kelly, Robert A. 15 June 2011 (has links) (PDF)
ViewPlus is collaborating with the American Physical Society (APS), DAISY, and several other companies and agencies to enable APS to publish its scientific journals in the highly accessible DAISY XML format. All text, math, and figures will be accessible to everybody, including people with print disabilities. The first experimental APS DAISY publications are targeted for 2010. All APS journals will eventually be published in DAISY form, and other scholarly publishers are expected to follow suit.
47

Implantação de sistemas avançados de planejamento (APS): um estudo de caso na indústria de laticínios. / Implementation of advanced planning systems (APS): a case study on the dairy industry.

Cecília Farid Zago 25 September 2013 (has links)
O contexto de elevada competitividade empresarial resulta em aumento das exigências por eficiência operacional, como redução dos níveis de estoques e melhoria nos níveis de serviço oferecido aos clientes. Desta forma as decisões tomadas no planejamento tático das companhias ganham complexidade e criticidade. Neste contexto há uma demanda por parte das empresas pela implantação de sistemas de apoio à decisão cada vez mais robustos. É neste cenário que a aplicação de APS no processo de S&OP adquire grande relevância, motivando o entendimento das melhorias trazidas ao processo de planejamento pela ferramenta. Este trabalho foi então norteado por duas questões de pesquisa: quais são os benefícios trazidos para o S&OP com a utilização de APS e quais são os fatores críticos para o sucesso da implantação deste sistema. Para isso, foi feito um estudo de caso em uma empresa que representa bem o contexto desta pesquisa, trata-se de uma grande empresa de lácteos da indústria alimentícia brasileira. Inserida em um setor com elevada competição de mercado e margens de lucro estreitas, há na empresa em questão uma grande necessidade de operar de maneira eficiente. Esta empresa possui múltiplas plantas industriais e passou recentemente pela implantação de um APS para suporte ao seu processo de S&OP, que é responsável pelo planejamento tático integrado da companhia. Como resultado desta pesquisa, identificaram-se os principais benefícios do APS ao processo de S&OP: uma maior confiança e assertividade no processo de planejamento e um melhor balanceamento de estoques em toda cadeia desta empresa. O projeto de implantação passou por algumas dificuldades que atrasaram o cronograma estabelecido, estes pontos merecem ser apontadas como os principais fatores críticos para o sucesso: é importante que o projeto conte com o apoio de toda alta gerência. Quanto à disponibilidade dos dados para desenvolvimento do sistema, é necessário que a empresa tenha processos transacionais integrados para permitir a padronização das informações, além de ser fundamental para o projeto que as pessoas envolvidas na implantação estejam disponíveis para trabalharem com foco no projeto. / Extreme business competition results in increased demands for operational efficiency, such as reducing inventory levels and improving the quality of services offered to customers. Consequently, the decisions in the companies tactical planning gain complexity and criticality. There is a demand by firms for the implementation of increasingly robust decision-support systems. The application of Advanced Planning Systems (APS) in the Sales and Operations Planning (S&OP) process is, then, of utmost importance, motivating the understanding of improvements this tool may add to planning. This dissertation is structured around two research questions: which benefits the use of APS brings to the S&OP, and what are the critical factors for the successful implementation of this system. A case study has been conducted in a company that suits the research: one of the major dairy companies in the Brazilian food industry. Placed in a sector with high market competition and narrow profit margins, one may note the great need the company in question has to operate efficiently. This firm owns several plants and has recently been through the implementation of an APS to support its S&OP process, which is responsible for the integrated tactical planning of the company. The research has identified the main benefits of the APS to the S&OP process: greater confidence and accuracy in planning, and better balancing of inventory throughout the whole firm chain. The deployment project went through specific difficulties that delayed its schedule. Those difficulties should be highlighted as the main critical factors to success, indicating it is important that the project be fully supported by all senior managers. Regarding the availability of data for system development, it is necessary that the company integrate transactional processes, allowing the standardization of information; besides, it is fundamental that the personnel involved in the implementation of the project be available to focus on it.
48

Komunikace v ZigBee sítích / Communication in ZigBee Networks

Majer, Tomáš January 2010 (has links)
Now days, we are more often meet sensors and sensor networks, which are used mainly in industrial fields. In this master thesis my target is sensor network Zigbee and usage of it. Internal structure of communication frames of APS application layer is presented here in details as well, which is used for control of sensors inside of sensor network. Main purpose of this master thesis is to design and implement application gateway between Internet and sensor network ZigBee. I present possible solution of communication protocol for transport over the Internet and processing of it by ZigBee coordinator. Thesis is written in style suitable for practical solution and results of solution are presented on model situations, which include discussion about possible improvements.
49

A techno-economic comparison between outdoor macro-cellular and indoor offloading solutions

Moulianitakis, Feidias January 2015 (has links)
Mobile penetration rates have already exceeded 100% in many countries. Nowadays, mobile phones are part of our daily lives not only for voice or short text messages but for a plethora of multimedia services they provide via their internet connection. Thus, mobile broadband has become the main driver for the evolution of mobile networks and it is estimated that until 2018 the mobile broadband traffic will exceed the level of 15 exabytes. This estimation is a threat to the current mobile networks which have to significantly improve their capacity performance. Furthermore, another important aspect is the fact that 80% of the mobile broadband demand comes from indoor environments which add to the signal propagation the burden of building penetration loss. Keeping these facts in mind, there are many potential solutions that can solve the problem of the increasing indoor mobile broadband demand. In general, there are two approaches; improve the existing macro-cellular networks by for example enhancing them with carrier aggregation or enter the buildings and deploy small cell solutions such as femtocells or WiFi APs. Both the academia and the industry have already shown interest in these two approaches demonstrating the importance of the problem. Various research papers and reports have been produced describing the technologies and presenting their capability to satisfy the perpetual increase in mobile broadband demand. However, according to the best of our knowledge, no research has been done so far that compares the two different approaches with a techno-economic perspective. Hence, the contribution of this thesis project is a holistic techno-economic study of the two approaches (macrocells with carrier aggregation and small cells) to encounter the tremendous growth of indoor mobile broadband demand. In order to achieve this goal, an indoor deployment scenario is presented and the different indoor and outdoor solutions are applied and studied in terms of radio performance (capacity) as well as total cost of ownership. The final result of the project is a comparison of the two approaches as well as a proposed strategy to deal with the problem. The result will help network operators to plan the evolution of their networks, vendors to focus their production as well as regulatory bodies to set the rules and supervise operators’ deployments. The simulations have shown that all the examined technologies are capable of supporting the mobile broadband demand of the studied scenario but macrocells enhanced with carrier aggregation is the most cost effective solution. However, if the requirements for guaranteed data rate and thus the QoS provided increase then eventually MNOs will have to abandon outdoor solutions and extend their infrastructure inside the buildings where the mobile data traffic is mainly generated. / Graden av mobilpenetration har redan nått över 100% i många länder. Nuförtiden är mobiltelefoner en del av vårt dagliga liv inte bara för röstsamtal eller korta textmeddelanden men också för en lång rad multimediatjänster som de tillhandahåller via sin Internetuppkoppling. På grund av detta har mobilt bredband blivit den huvudsakliga drivkraften för utvecklingen av mobila nätverk och det uppskattas att fram till 2018 kommer den mobila bredbandstrafiken överstiga 15 exabyte. Denna uppskattning är ett hot mot de nuvarande mobila nätverken som måste öka sin kapacitet avsevärt. Utöver det är en annan viktig aspekt det faktum att 80% av efterfrågan på mobilt bredband kommer från inomhusmiljöer vilket ger spridningen av radiosignaler problem med minskad penetrationsförmåga orsakad av byggnaden. Med hänsyn till dessa faktorer finns det många potentiella lösningar som kan åtgärda problemet med den ökande efterfrågan på bredband i inomhusmiljöer. Generellt sett finns två tillvägagångssätt; förbättra de existerande makrocells-baserade nätverken exempelvis genom att förstärka dem med carrier aggregation alternativt att i byggnader installera lösningar baserade på små celler som femtoceller eller WiFi-accesspunkter. Både den akademiska världen och industrin har redan visat intresse för dessa två tillvägagångssätt vilket visar att detta är ett viktigt problem. Ett antal forskningsartiklar och rapporter har producerats vilka beskriver teknologierna och deras förmåga att tillfredställa den ständigt ökande efterfrågan på mobilt bredband. Med det sagt, enligt vår kunskap i dagsläget har dock ingen forskning hittills utförts som jämför dessa två tillvägagångssätt från ett teknoekonomiskt perspektiv. Följaktligen är det bidrag denna uppsats ger en holistisk teknoekonomisk studie av de två metoderna (makroceller med carrier aggregation och lösningar baserade på små celler) för att möta den mycket stora ökningen av efterfrågan på mobilt bredband inomhus. För att uppnå detta mål presenteras ett scenario med installation i inomhusmiljö och de olika lösningarna för inomhus- och utomhusmiljöer appliceras och studeras med hänsyn till radioprestanda (kapacitet) och även total ägandekostnad. Projektets slutgiltiga resultat är en jämförelse mellan de två metoderna och ett förslag på en strategi som kommer hjälpa nätverksoperatörer att planera utvecklingen av sina nätverk, leverantörer att fokusera sin tillverkning och tillsynsmyndigheter att upprätta regler samt övervaka att dessa efterföljs. Simuleringarna har visat att alla de granskade teknikerna klarar av att uppfylla efterfrågan på mobilt bredband i de studerade scenariona men att makroceller med carrier aggregation är den mest kostnadseffektiva lösningen. Men om kraven på garanterad datahastighet, och med det den QoS som tillhandahålls, ökar så kommer MNOs till slut att behöva överge utomhuslösningar och utöka deras infrastruktur inuti byggnader där den mobila datatrafiken i huvudsak genereras.
50

Elektronisk krigföring mot sensorer i varnar- och motverkanssystem / Electronic warfare against sensors used in active protection systems

Nilsson, Jesper January 2021 (has links)
This report on the subject of Systems Science for Defence and Security, aims to study the possibility for electronic warfare (EW) against the radar in active protection system (APS) on ground combat vehicles. The goal of the EW is to ensure effect of current anti-tank systems against an enemy equipped with APS. Given that the radar is susceptible to jamming, (1) Which opportunities would an EW-system used in conjunction with an anti-tank system, bestow on a successful engagement? (2) Which effect could jamming of an APS result in, and what type of jamming would yield this desired effect?  The result concludes that an APS would increase the statistical number of needed anti-tank projectiles in a given engagement with a combat vehicle by 700 %, from a stated number of five to six to 35–43. This increase shows how the efficiency of an APS is linked to needed anti-tank systems for the same effect, but also the potential gain from employing an EW-system. Studying the use of stand-off jamming, where the jamming is produced in a separate system, there’s no need for new development of weapons systems or munitions. The jamming should employ a technique of combined range and velocity deception (CRV) or noise to successfully lower the efficiency of the APS. Angle deception have arisen as a desirable technique, with promise of an increase of survivability of EW- and anti-tank units, and further studies are therefore interest. / Detta självständiga arbete på grundnivå inom ämnet försvarssystem behandlar möjligheter till aktiv radarstörning av varnar- och motverkanssystem (VMS), i syfte att erhålla verkan med befintliga burna pansarvärnssystem mot stridsfordon. Givet att aktiv radarstörning kan användas mot ett varnar- och motverkanssystem med förstörande motmedel; (1)Vilka möjligheter till verkan ger ett telekrigsystem med aktiv radarstörning i kombination med ett pansarvärnssystem?(2)Vilken typ av aktiv radarstörning är lämplig och vilken effekt på det störda systemet kan förväntas?  Arbetet visar på effekten VMS statistiskt har på duellen mellan stridsfordon och pansarvärnssystem. Beräkningarna utgår ifrån påståendet att det krävs fem till sex pansarvärnprojektiler för nedkämpning av ett stridsfordon, vilket ökar till 35-43st då fordonet utrustas med VMS. Ökningen på cirka 700% visar dels på hur effektiviteten hos VMS höjer antalet erfordrade pansarvärnsvapen för att nå samma effekt, men även den potentiella vinningen att sänka effektiviteten genom telekrig. Arbetet studerade nyttjandet av bakgrundsstörning, då genereringen av störsignalen sker i ett separat telekrigsystem, vilket inte kräver utveckling av nya vapensystem eller ammunition. För utformning av störningen faller en kombinerad hastighet och avstånds vilseledning (CRV) eller brus lämplig och anses sänka effektiviteten hos VMS. Vinkelavhakning har i arbetet visat sig medföra stora förtjänster för ökad överlevnad hos telekrig/pansarvärnsenheter och vidare forskning är därför intressant.

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