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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

The Hierarchical Core-Based Multicast Routing Protocol in Wireless Ad Hoc Networks

Lan, Yin-Ming 29 June 2003 (has links)
Wireless Ad hoc Network is a self-organizing network. It consists of many mobile nodes and it is a dynamic topology network. It is an impermanent wireless network. It is not an infrastructure-based network, and can be deployed in a short time. Therefore, it can be highly used in some emergency situations, such as, in emergency rescue actions, in military ¡Ketc. As a result, multicast plays an important role here. But before putting it into applications, we have to consider some problems such as scalability, control overhead, data delivery ratio, and routing delay. Some approaches we have learned can¡¦t resolve these problems. So, here we propose a new multicast routing protocol. It¡¦s a kind of core-based multicast protocols. First, we divide whole network into several sub-networks called as cluster, and pick up a node as the cluster core node from each cluster, and this cluster core node will manage all member nodes in this area. All cluster core nodes will connect to each other. Source node in each cluster will send messages to the it¡¦s cluster core-node and then the cluster core node will forward this message to other cluster core-nodes. Finally, the messages will be sent to the destination, member nodes of a multicast session. In this multicast routing protocol, we reduce control packets by localization and lower control overhead. With localization, every nodes only have information from near-by nodes, and this reduce the delay time of routing effectively. More, localization does not increase too much nodes when a message travels from A to B and raise the data delivery ratio. And because of localization, whole network is scalability.
2

PSEUDO DIAMETER - A NOVEL CONCEPT IN DESIGNING HIGHLY BANDWIDTH EFFICIENT MULTICAST ROUTING PROTOCOLS

Koneru, Sindoora 01 August 2014 (has links)
Multicasting is preferred over multiple unicasts from the viewpoint of better utilization of one of the most important network resources, namely network bandwidth. Multicasting can be done in two different ways: source based tree approach and shared tree approach. This research focuses on improving bandwidth utilization of source based multicast routing protocols and also provides core selection approaches for shared tree multicasting. In this work, we have defined new concepts called pseudo diameter and super pseudo diameter by using the routing information present in Distance Vector Routing (DVR) tables. Pseudo diameter relates to the physical locations of routers and is used to control the flow of packets along the broadcast tree. Super pseudo diameter relates to the physical location of group members and is used to control the flow of packets along the multicast tree. This location aspect of routers and group members have been incorporated into the existing broadcast and multicast protocols to achieve a much improved bandwidth utilization compared to the existing approaches. These concepts have also been used in developing both static and group based core selection approaches. Pseudo diameter used in static core selection approach, and super pseudo diameter used in group based core selection approach, generates secondary and tertiary cores along with primary core to achieve fault tolerance. Besides DVR, the other widely used unicast routing protocol is the Link State Routing protocol (LSR). We have shown that a similar concept to pseudo diameter called sub diameter can be used on networks using LSR tables to achieve better bandwidth utilization in source based multicasting and in selecting a core for shared tree multicasting.
3

Automating IEEE 1500 wrapper insertion

Huss, Niklas January 2009 (has links)
<p>Integrated circuits (ICs) are becoming increasingly complex, which leadsto long design and development times. Designing ICs in a modular fashionis efficient to shorten design and development times. Due to imperfection inIC manufacturing, all ICs are tested. An IC designed in a modular fashioncan be tested in a modular manner. To enable modular test, the IEEE 1500std has been developed to enable isolation and access of modules. Whilethe IEEE 1500 std is adopted, there is yet no commercial tool available.</p><p>In this thesis we have (1) developed an IEEE 1500 std wrapper and (2)included it in a design flow based on a commercial tool, and developed scriptto automate the process. Given a module in VHDL, our design automationautomatically makes synthesis, scan insertion, test generation (ATPG), andwrapper insertion. We have applied the design flow to several benchmarksand through simulation verified the correctness.</p>
4

Lógica e escalonamento de teste para sistemas com redes intra-chip baseadas em topologia de malha

Amory, Alexandre de Morais January 2007 (has links)
Com o avanço da tecnologia de fabricação de chips o atraso em fios globais será maior que o atraso em portas lógicas. Além disso, fios globais longos são mais suscetíveis a problemas de integridade como crosstalk. Uma proposta recente de interconnecção global chamada redes intra-chip reduz essas limitações referentes a fios longos. Além dessas vantagens, redes intra-chip permitem desacoplar comunicação e computação, dividindo um sistema em sub tarefas independentes. Devido as essas vantagens é possível integrar mais lógica em um chip que usa redes intra-chip. Entretanto, o acréscimo de lógica no chip aumenta o custo de teste. Os módulos do chip precisam de mecanismos para transportar dados de teste, que são tipicamente barramentos usados exclusivamente para teste. Entretanto, como mencionado anteriormente, fios globais são caros e acrescentar barramentos de teste pode não ser possível em um futuro próximo. Por outro lado, uma rede intra-chip tem acesso a maioria dos módulos do chip. Esta rede pode ser usada para transportar dados de teste, evitando o acréscimo de barramentos dedicados ao teste. O objetivo dessa tese é estudar o uso de redes intra-chip para o transporte de dados de teste, enfatizando uma abordagem genérica que possa ser aplicada a uma dada rede. Para tanto, essa tese foi divida em três partes: modelos, projeto, e otimização. A tese propõe um modelo funcional de rede que é compatível com a maioria das recém propostas redes intra-chip. O modelo de teste, baseado no modelo funcional da rede, compreende o conjunto de informações necessárias para otimizar a arquitetura de teste. A arquitetura de teste, por sua vez, consiste de lógica para teste e algoritmo de otimização. A lógica de teste compreende lógica para ATE interface e lógica envoltória para módulos de hardware. Os algoritmos otimizam o tempo de teste e a área de lógica de teste no nível dos módulos e no nível do chip. Uma arquitetura convencional de teste de SoCs baseada em barramento de teste dedicado foi comparada com a arquitetura proposta para SoCs baseados em redes intra-chip. Os resultados apontam que o tempo de teste do SoC com a arquitetura proposta aumenta em média 5%. Os resultados também mostram que a lógica de teste da arquitetura proposta é cerca de 20% maior que na arquitetura de teste convencional. Por outro lado, o fluxo de projeto baseado na arquitetura de teste proposta é mais simples que a convencional. Além disso, a arquitetura proposta reduz o nÚmero de fios globais em torno de 20% a 50% para SoCs complexos. Estes resultados demonstram que a arquitetura proposta é melhor para sistemas complexos com um grande nÚmero de módulos. / With the advance of microchip technology, global and long wires will cost more in terms of delay than in terms of logic gates. ln addition, long wires are more susceptible to signal integrity problems such as crosstalk. A recently proposed global interconnect called network-on-chip alleviates the limitation of long wires. Moreover, on-chip networks allow decoupling communication and computation to divide a complete system into manageable and independent sub tasks. Thus, it is possible to integrate more logic into the chip using network-on-chip. However, the complexity growth of cores also increases the test costs since more logic is embedded into a single chip. These embedded cores need a test access mechanism for test data transportation, typically implemented as test-dedicated buses. As mentioned before, global wires are expensive, then, adding test buses may not be feasible in the near future. On the other hand, the on-chip network has access to most cores of the chip. This network could be used also for test data transportation, avoiding additional test-dedicated buses. The goal of this thesis is to study the reuse of on-chip networks for test data transportation, looking for a general reuse approach that can be easily used in a given network. To reach this goal, the thesis is divided in three parts: models, design, and optimization. This thesis proposes a functional model of a network, compatible with most recently proposed best-effort on-chip networks. Based on this functional model, a test model is devised. The test model comprises of a set of necessary and sufficient information required to optimize the test architecture. The test architecture consists of DfT logic and scheduling algorithm. The design of DfT logic comprises adaptation logic for the external tester and test wrappers for the modules. The optimization procedure, focused on mesh-based best-effort NoCs, schedules test data such that the chip test length and DfT silicon are a are minimized. A conventional SoC test architecture based on test-dedicated buses is compared to the proposed approach for best-effort NoCs. The experimental results show that SoC test length has increased 5% on average. The results have also shown that the are a overhead for proposed DfT is around +20% compared to the silicon area to implement the DfT of a convehtional test architecture. On the other hand, we have also presented a simpler design fiow and 20% to 50% of global wiring savings due to the use of NoC for test data transportation. The results corroborate with the conclusion that the proposed NoC reuse is a good approach for complex systems based on a large number of cores and routers.
5

Lógica e escalonamento de teste para sistemas com redes intra-chip baseadas em topologia de malha

Amory, Alexandre de Morais January 2007 (has links)
Com o avanço da tecnologia de fabricação de chips o atraso em fios globais será maior que o atraso em portas lógicas. Além disso, fios globais longos são mais suscetíveis a problemas de integridade como crosstalk. Uma proposta recente de interconnecção global chamada redes intra-chip reduz essas limitações referentes a fios longos. Além dessas vantagens, redes intra-chip permitem desacoplar comunicação e computação, dividindo um sistema em sub tarefas independentes. Devido as essas vantagens é possível integrar mais lógica em um chip que usa redes intra-chip. Entretanto, o acréscimo de lógica no chip aumenta o custo de teste. Os módulos do chip precisam de mecanismos para transportar dados de teste, que são tipicamente barramentos usados exclusivamente para teste. Entretanto, como mencionado anteriormente, fios globais são caros e acrescentar barramentos de teste pode não ser possível em um futuro próximo. Por outro lado, uma rede intra-chip tem acesso a maioria dos módulos do chip. Esta rede pode ser usada para transportar dados de teste, evitando o acréscimo de barramentos dedicados ao teste. O objetivo dessa tese é estudar o uso de redes intra-chip para o transporte de dados de teste, enfatizando uma abordagem genérica que possa ser aplicada a uma dada rede. Para tanto, essa tese foi divida em três partes: modelos, projeto, e otimização. A tese propõe um modelo funcional de rede que é compatível com a maioria das recém propostas redes intra-chip. O modelo de teste, baseado no modelo funcional da rede, compreende o conjunto de informações necessárias para otimizar a arquitetura de teste. A arquitetura de teste, por sua vez, consiste de lógica para teste e algoritmo de otimização. A lógica de teste compreende lógica para ATE interface e lógica envoltória para módulos de hardware. Os algoritmos otimizam o tempo de teste e a área de lógica de teste no nível dos módulos e no nível do chip. Uma arquitetura convencional de teste de SoCs baseada em barramento de teste dedicado foi comparada com a arquitetura proposta para SoCs baseados em redes intra-chip. Os resultados apontam que o tempo de teste do SoC com a arquitetura proposta aumenta em média 5%. Os resultados também mostram que a lógica de teste da arquitetura proposta é cerca de 20% maior que na arquitetura de teste convencional. Por outro lado, o fluxo de projeto baseado na arquitetura de teste proposta é mais simples que a convencional. Além disso, a arquitetura proposta reduz o nÚmero de fios globais em torno de 20% a 50% para SoCs complexos. Estes resultados demonstram que a arquitetura proposta é melhor para sistemas complexos com um grande nÚmero de módulos. / With the advance of microchip technology, global and long wires will cost more in terms of delay than in terms of logic gates. ln addition, long wires are more susceptible to signal integrity problems such as crosstalk. A recently proposed global interconnect called network-on-chip alleviates the limitation of long wires. Moreover, on-chip networks allow decoupling communication and computation to divide a complete system into manageable and independent sub tasks. Thus, it is possible to integrate more logic into the chip using network-on-chip. However, the complexity growth of cores also increases the test costs since more logic is embedded into a single chip. These embedded cores need a test access mechanism for test data transportation, typically implemented as test-dedicated buses. As mentioned before, global wires are expensive, then, adding test buses may not be feasible in the near future. On the other hand, the on-chip network has access to most cores of the chip. This network could be used also for test data transportation, avoiding additional test-dedicated buses. The goal of this thesis is to study the reuse of on-chip networks for test data transportation, looking for a general reuse approach that can be easily used in a given network. To reach this goal, the thesis is divided in three parts: models, design, and optimization. This thesis proposes a functional model of a network, compatible with most recently proposed best-effort on-chip networks. Based on this functional model, a test model is devised. The test model comprises of a set of necessary and sufficient information required to optimize the test architecture. The test architecture consists of DfT logic and scheduling algorithm. The design of DfT logic comprises adaptation logic for the external tester and test wrappers for the modules. The optimization procedure, focused on mesh-based best-effort NoCs, schedules test data such that the chip test length and DfT silicon are a are minimized. A conventional SoC test architecture based on test-dedicated buses is compared to the proposed approach for best-effort NoCs. The experimental results show that SoC test length has increased 5% on average. The results have also shown that the are a overhead for proposed DfT is around +20% compared to the silicon area to implement the DfT of a convehtional test architecture. On the other hand, we have also presented a simpler design fiow and 20% to 50% of global wiring savings due to the use of NoC for test data transportation. The results corroborate with the conclusion that the proposed NoC reuse is a good approach for complex systems based on a large number of cores and routers.
6

Lógica e escalonamento de teste para sistemas com redes intra-chip baseadas em topologia de malha

Amory, Alexandre de Morais January 2007 (has links)
Com o avanço da tecnologia de fabricação de chips o atraso em fios globais será maior que o atraso em portas lógicas. Além disso, fios globais longos são mais suscetíveis a problemas de integridade como crosstalk. Uma proposta recente de interconnecção global chamada redes intra-chip reduz essas limitações referentes a fios longos. Além dessas vantagens, redes intra-chip permitem desacoplar comunicação e computação, dividindo um sistema em sub tarefas independentes. Devido as essas vantagens é possível integrar mais lógica em um chip que usa redes intra-chip. Entretanto, o acréscimo de lógica no chip aumenta o custo de teste. Os módulos do chip precisam de mecanismos para transportar dados de teste, que são tipicamente barramentos usados exclusivamente para teste. Entretanto, como mencionado anteriormente, fios globais são caros e acrescentar barramentos de teste pode não ser possível em um futuro próximo. Por outro lado, uma rede intra-chip tem acesso a maioria dos módulos do chip. Esta rede pode ser usada para transportar dados de teste, evitando o acréscimo de barramentos dedicados ao teste. O objetivo dessa tese é estudar o uso de redes intra-chip para o transporte de dados de teste, enfatizando uma abordagem genérica que possa ser aplicada a uma dada rede. Para tanto, essa tese foi divida em três partes: modelos, projeto, e otimização. A tese propõe um modelo funcional de rede que é compatível com a maioria das recém propostas redes intra-chip. O modelo de teste, baseado no modelo funcional da rede, compreende o conjunto de informações necessárias para otimizar a arquitetura de teste. A arquitetura de teste, por sua vez, consiste de lógica para teste e algoritmo de otimização. A lógica de teste compreende lógica para ATE interface e lógica envoltória para módulos de hardware. Os algoritmos otimizam o tempo de teste e a área de lógica de teste no nível dos módulos e no nível do chip. Uma arquitetura convencional de teste de SoCs baseada em barramento de teste dedicado foi comparada com a arquitetura proposta para SoCs baseados em redes intra-chip. Os resultados apontam que o tempo de teste do SoC com a arquitetura proposta aumenta em média 5%. Os resultados também mostram que a lógica de teste da arquitetura proposta é cerca de 20% maior que na arquitetura de teste convencional. Por outro lado, o fluxo de projeto baseado na arquitetura de teste proposta é mais simples que a convencional. Além disso, a arquitetura proposta reduz o nÚmero de fios globais em torno de 20% a 50% para SoCs complexos. Estes resultados demonstram que a arquitetura proposta é melhor para sistemas complexos com um grande nÚmero de módulos. / With the advance of microchip technology, global and long wires will cost more in terms of delay than in terms of logic gates. ln addition, long wires are more susceptible to signal integrity problems such as crosstalk. A recently proposed global interconnect called network-on-chip alleviates the limitation of long wires. Moreover, on-chip networks allow decoupling communication and computation to divide a complete system into manageable and independent sub tasks. Thus, it is possible to integrate more logic into the chip using network-on-chip. However, the complexity growth of cores also increases the test costs since more logic is embedded into a single chip. These embedded cores need a test access mechanism for test data transportation, typically implemented as test-dedicated buses. As mentioned before, global wires are expensive, then, adding test buses may not be feasible in the near future. On the other hand, the on-chip network has access to most cores of the chip. This network could be used also for test data transportation, avoiding additional test-dedicated buses. The goal of this thesis is to study the reuse of on-chip networks for test data transportation, looking for a general reuse approach that can be easily used in a given network. To reach this goal, the thesis is divided in three parts: models, design, and optimization. This thesis proposes a functional model of a network, compatible with most recently proposed best-effort on-chip networks. Based on this functional model, a test model is devised. The test model comprises of a set of necessary and sufficient information required to optimize the test architecture. The test architecture consists of DfT logic and scheduling algorithm. The design of DfT logic comprises adaptation logic for the external tester and test wrappers for the modules. The optimization procedure, focused on mesh-based best-effort NoCs, schedules test data such that the chip test length and DfT silicon are a are minimized. A conventional SoC test architecture based on test-dedicated buses is compared to the proposed approach for best-effort NoCs. The experimental results show that SoC test length has increased 5% on average. The results have also shown that the are a overhead for proposed DfT is around +20% compared to the silicon area to implement the DfT of a convehtional test architecture. On the other hand, we have also presented a simpler design fiow and 20% to 50% of global wiring savings due to the use of NoC for test data transportation. The results corroborate with the conclusion that the proposed NoC reuse is a good approach for complex systems based on a large number of cores and routers.
7

Automating IEEE 1500 wrapper insertion

Huss, Niklas January 2009 (has links)
Integrated circuits (ICs) are becoming increasingly complex, which leadsto long design and development times. Designing ICs in a modular fashionis efficient to shorten design and development times. Due to imperfection inIC manufacturing, all ICs are tested. An IC designed in a modular fashioncan be tested in a modular manner. To enable modular test, the IEEE 1500std has been developed to enable isolation and access of modules. Whilethe IEEE 1500 std is adopted, there is yet no commercial tool available. In this thesis we have (1) developed an IEEE 1500 std wrapper and (2)included it in a design flow based on a commercial tool, and developed scriptto automate the process. Given a module in VHDL, our design automationautomatically makes synthesis, scan insertion, test generation (ATPG), andwrapper insertion. We have applied the design flow to several benchmarksand through simulation verified the correctness.
8

Generic Architecture for Power-Aware Routing in Wireless Sensor Networks

Ranjan, Rishi 18 June 2004 (has links)
This work describes the design and implementation of a generic architecture to provide a collective solution for power-aware routing to a wide range of problems in wireless sensor network environments. Power aware-routing is integral to the proposed solutions for different problems. These solutions try to achieve power-efficient routing specific to the problem domain. This can lead to challenging technical problems and deployment barriers when attempting to integrate the solutions. This work extracts various factors to be considered for a range of problems in wireless sensor networks and provides a generic framework for efficient power-aware routing. The architecture aims to relieve researchers from considering power management in their design. We have identified coupling between sources and sinks as the main factor for different design choices for a range of problems. We developed a core-based hierarchical routing framework for efficient power-aware routing that is used to decouple the sources from sinks. The architecture uses only local interaction for scalability and stability in a dynamic network. The architecture provides core-based query forwarding and data dissemination. It uses data aggregation and query aggregation at core nodes to reduce the amount of data to be transmitted. The architecture can be easily extended to incorporate protocols to provide QoS and security to the applications. We use network simulations to evaluate the performance of cluster formation and energy efficiency of the algorithm. Our results show that energy efficiency of the algorithm is better when the transmission range is kept to a minimum for network connectivity as compared to adjustable transmission range.
9

New Carbazole-, Indole-, and Diphenylamine-Based Emissive Compounds: Synthesis, Photophysical Properties, and Formation of Nanoparticles

Panthi, Krishna K. 02 March 2011 (has links)
No description available.
10

EVALUATION OF SOURCE ROUTING FOR MESH TOPOLOGY NETWORK ON CHIP PLATFORMS

MUBEEN, SAAD January 2009 (has links)
<p>Network on Chip is a scalable and flexible communication infrastructure for the design of core based System on Chip. Communication performance of a NoC depends heavily on the routing algorithm. Deterministic and adaptive distributed routing algorithms have been advocated in all the current NoC architectural proposals. In this thesis we make a case for the use of source routing for NoCs, especially for regular topologies like mesh. The advantages of source routing include in-order packet delivery; faster and simpler router design; and possibility of mixing non-minimal paths in a mainly minimal routing. We propose a method to compute paths for various communications in such a way that traffic congestion is avoided while ensuring deadlock free routing. We also propose an efficient scheme to encode the paths.</p><p>We developed a tool in Matlab that computes paths for source routing for both general and application specific communications. Depending upon the type of traffic, this tool computes paths for source routing by selecting best routing algorithm out of many routing algorithms. The tool uses a constructive path improvement algorithm to compute paths that give more uniform link load distribution. It also generates different types of traffics. We also developed a simulator capable of simulating source routing for mesh topology NoC. The experiments and simulations which we performed were successful and the results show that the advantages of source routing especially lower packet latency more than compensate its disadvantages. The results also demonstrate that source routing can be a good routing candidate for practical core based SoCs design using network on chip communication infrastructure.</p>

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