The Experts below are selected from a list of 15 Experts worldwide ranked by ideXlab platform
Mikel Lujan - One of the best experts on this subject based on the ideXlab platform.
-
designing low power low latency networks on chip by optimally combining electrical and optical links
High-Performance Computer Architecture, 2017Co-Authors: Sebastian Werner, Javier Navaridas, Mikel LujanAbstract:Optical on-chip communication is considered a promising candidate to overcome latency and energy bottlenecks of electrical interconnects. Although recently proposed hybrid Networks-on-chip (NoCs), which implement both electrical and optical links, improve power efficiency, they often fail to combine these two interconnect technologies efficiently and suffer from considerable laser power overheads caused by high-bandwidth optical links. We argue that these overheads can be avoided by inserting a higher quantity of low-bandwidth optical links in a topology, as this yields lower optical loss and in turn laser power. Moreover, when optimally combined with electrical links for short distances, this can be done without trading off latency. We present the effectiveness of this concept with Lego, our hybrid, mesh-based NoC that provides high power efficiency by utilizing electrical links for local traffic, and low-bandwidth optical links for long distances. Electrical links are placed systematically to outweigh the Serialization Delay introduced by the optical links, simplify router microarchitecture, and allow to save optical resources. Our routing algorithm always chooses the link that offers the lowest latency and energy. Compared to state-of-the-art proposals, Lego increases throughput-per-watt by at least 40%, and lowers latency by 35% on average for synthetic traffic. On SPLASH-2/PARSEC workloads, Lego improves power efficiency by at least 37% (up to 3.5x).
Sebastian Werner - One of the best experts on this subject based on the ideXlab platform.
-
designing low power low latency networks on chip by optimally combining electrical and optical links
High-Performance Computer Architecture, 2017Co-Authors: Sebastian Werner, Javier Navaridas, Mikel LujanAbstract:Optical on-chip communication is considered a promising candidate to overcome latency and energy bottlenecks of electrical interconnects. Although recently proposed hybrid Networks-on-chip (NoCs), which implement both electrical and optical links, improve power efficiency, they often fail to combine these two interconnect technologies efficiently and suffer from considerable laser power overheads caused by high-bandwidth optical links. We argue that these overheads can be avoided by inserting a higher quantity of low-bandwidth optical links in a topology, as this yields lower optical loss and in turn laser power. Moreover, when optimally combined with electrical links for short distances, this can be done without trading off latency. We present the effectiveness of this concept with Lego, our hybrid, mesh-based NoC that provides high power efficiency by utilizing electrical links for local traffic, and low-bandwidth optical links for long distances. Electrical links are placed systematically to outweigh the Serialization Delay introduced by the optical links, simplify router microarchitecture, and allow to save optical resources. Our routing algorithm always chooses the link that offers the lowest latency and energy. Compared to state-of-the-art proposals, Lego increases throughput-per-watt by at least 40%, and lowers latency by 35% on average for synthetic traffic. On SPLASH-2/PARSEC workloads, Lego improves power efficiency by at least 37% (up to 3.5x).
Juliana Maciel De Souza - One of the best experts on this subject based on the ideXlab platform.
-
Trajetória do estudante no curso noturno de odontologia da Universidade Federal do Rio Grande do Sul : perfil do ingressante, situação acadêmica e motivos de retenção e evasão
Universidade Federal do Rio Grande do Sul, 2014Co-Authors: Juliana Maciel De SouzaAbstract:Introdução: A organização e a oferta do ensino superior têm passado por intensas transformações, contemplando a ampliação de vagas em cursos oferecidos nas instituições públicas de ensino superior. Mas, o sucesso na universidade não se restringe ao acesso à vaga, passa também pela permanência no curso e sua conclusão. Objetivo: Analisar a trajetória acadêmica do estudante do curso noturno de Odontologia da Universidade Federal do Rio Grande do Sul (UFRGS), por meio da caracterização do perfil do estudante, situação acadêmica e compreensão dos motivos de retenção e evasão. Percurso metodológico: Estudo de caso predominantemente qualitativo, cujo campo de investigação foi o curso noturno de graduação em Odontologia da UFRGS. A coleta de dados aconteceu em três momentos: questionário semiestruturado para caracterizar o perfil sociodemográfico do ingressante, sua opção pela profissão e expectativas em relação ao curso (n=118); análise documental do histórico escolar dos estudantes que ingressaram no curso noturno de Odontologia para verificar sua situação acadêmica (n=121); entrevistas semiestruturadas com os estudantes em situação de retenção e evasão (n=16), e com os professores das disciplinas do curso em que houve a reprovação (n=8). O tamanho da amostra foi definido pelo critério da saturação. Os dados objetivos foram digitados no software IBM SPSS Statistics versão 18.0 para Windows e analisados por meio da distribuição de frequências. Já os dados qualitativos foram gravados em equipamento digital, transcritos e importados para o software ATLAS.ti, sendo interpretados pela análise temática de conteúdo de Bardin. A pesquisa foi aprovada pelo Comitê de Ética em Pesquisa da Universidade. Resultados: O perfil do estudante que ingressou no curso noturno, em sua maior parte, é de jovens, do sexo feminino, solteiro, com formação básica em escola pública e que trabalha. Esses estudantes sentiam-se seguros ou completamente seguros pela escolha profissional e seus principais motivos para esta escolha foram a ‘realização pessoal e profissional’, ‘segurança e tranquilidade no futuro, posição social e conforto financeiro’ e ‘interesse em atuar na comunidade’. As expectativas mais citadas em relação ao curso foram encontrar ‘uma formação qualificada’, 'realização profissional’ e ‘realização pessoal/de um sonho/vocação’. Sobre a situação acadêmica, 40,4% dos estudantes encontrava-se fora da seriação aconselhada (retenção), principalmente por reprovação ou associação entre reprovação e trancamento de matrícula. O percentual de evasão foi de 19,9% e a maioria dos estudantes que saiu do curso noturno optou por seguir o curso diurno de Odontologia da UFRGS. Dentre os motivos que levaram à evasão e retenção no curso, estudantes e professores destacaram questões relacionadas à chegada e adaptação do estudante no curso, conciliação entre estudo e trabalho, vivências de sala de aula, o processo de avaliação da aprendizagem, o lugar da instituição de ensino no desempenho dos estudantes (organização de horários, matrícula anual, integração entre curso diurno e noturno) e o tempo de duração do curso. Considerações finais: O curso noturno de Odontologia da UFRGS está inserido no contexto da política de expansão e reestruturação do ensino superior (REUNI). É um curso recente, que ainda não possui nenhuma turma de concluintes e a trajetória acadêmica de seus estudantes está sendo construída a cada semestre. A adaptação no curso, conciliação entre estudo e trabalho, vivências de sala de aula, avaliação da aprendizagem, organização de horários, matrícula anual, integração entre curso diurno e noturno e o tempo de duração do curso foram motivos relacionados à retenção e evasão. Recomenda-se que esta análise seja divulgada e discutida com a comunidade acadêmica da Faculdade de Odontologia, no sentido de promover estratégias para a permanência e conclusão do estudante no curso noturno.Introduction: The organization and the offer of higher education has been through an intense transformation, concerning places for enrollment on courses in public institutions. However, success at the university is not restricted to vacancy access. It also involves staying the course to it’s conclusion. Objective: Analyze the academic trajectory of students of evening undergraduate degree courses in Dentistry at the Federal University of Rio Grande do Sul (UFRGS), by characterization of student's profile, academic situation and understanding of the reasons for Delay in finishing courses and dropout. Methodological Approach: Predominantly qualitative case study whose field of research was the evening undergraduate degree in Dentistry at UFRGS. The data collection took place in three stages: semistructured questionnaire to characterize the sociodemographic profile of the incoming student, their choice of profession and expectations for the course (n=118); document analysis of school records of students who enrolled in evening undergraduate degrees in Dentistry to verify their academic situation (n=121); semistructured interviews with students who are repeating and those who are droping out, and for the teachers of the subjects of the course where there was a failure (n=24). The sample size is defined by saturation criteria. The objective data was entered into the software IBM SPSS Statistics version 18.0 to Windows and analysed through frequency distribution. Qualitative data was recorded digitally, transcribed and imported into the software ATLAS.ti, and interpreted by Bardin thematic content analysis. The research was approved by University Research Ethics Committee. Results: The profile of the incoming student of the evening undergraduate degree course in Dentistry was predominantly young, female, single, with basic education in public school and employed. These students feel safe or completely safe about their professional choice with their main reasons for this choice been ‘personal and professional fulfillment’, ‘safety and peace for the future, social position and financial comfort’ and ‘interest in working in the community’. The most cited expectations about the course were to have ‘a qualified education’, ‘professional fulfillment’ and ‘personal/dream/vocational fulfillment’. Concerning the academic situation, 40,4% of students remained outside the recommended Serialization (Delay in finishing courses), mainly because of disapproval or association between disapproval and enrollment locking. The dropout percentage was 19,9% with most of the students who left the evening undergraduate degree choosing to follow the diurnal undergraduate degree in Dentistry at UFRGS. Among the reasons for dropout and Delay in finishing courses were students and professors highlighting issues related to student arrival and adaptation of the course, reconciling work and study, experiences of classroom studies, process of learning assessment, the post of the educational institution on student performance (timetabling, annual enrollment, integration between daytime and evening course) and the duration of the course. Final Considerations: The evening undergraduate degree in Dentistry at UFRGS is inserted in the context of political expansion and restructuring of higher education (REUNI). It is a recent course, which does not have as yet undergraduate who have fully completed the course. The academic careers are therefore being constructed every semester. Adaptation of the course, reconciling work and study, experiences to the classroom, assessment of learning, organizing schedules, annual enrollment, integration between daytime and evening course and the duration of the course were reasons related to Delay in finishing courses and dropout. It is recommended that the analysis presented here is disclosed and discussed within the academic community of the College of Dentistry to promote strategies for permanence and completion of the evening course by students
Javier Navaridas - One of the best experts on this subject based on the ideXlab platform.
-
designing low power low latency networks on chip by optimally combining electrical and optical links
High-Performance Computer Architecture, 2017Co-Authors: Sebastian Werner, Javier Navaridas, Mikel LujanAbstract:Optical on-chip communication is considered a promising candidate to overcome latency and energy bottlenecks of electrical interconnects. Although recently proposed hybrid Networks-on-chip (NoCs), which implement both electrical and optical links, improve power efficiency, they often fail to combine these two interconnect technologies efficiently and suffer from considerable laser power overheads caused by high-bandwidth optical links. We argue that these overheads can be avoided by inserting a higher quantity of low-bandwidth optical links in a topology, as this yields lower optical loss and in turn laser power. Moreover, when optimally combined with electrical links for short distances, this can be done without trading off latency. We present the effectiveness of this concept with Lego, our hybrid, mesh-based NoC that provides high power efficiency by utilizing electrical links for local traffic, and low-bandwidth optical links for long distances. Electrical links are placed systematically to outweigh the Serialization Delay introduced by the optical links, simplify router microarchitecture, and allow to save optical resources. Our routing algorithm always chooses the link that offers the lowest latency and energy. Compared to state-of-the-art proposals, Lego increases throughput-per-watt by at least 40%, and lowers latency by 35% on average for synthetic traffic. On SPLASH-2/PARSEC workloads, Lego improves power efficiency by at least 37% (up to 3.5x).
Deshpande Hrishikesh - One of the best experts on this subject based on the ideXlab platform.
-
Multipath Router Architectures to Reduce Latency in Network-on-Chips
2012Co-Authors: Deshpande HrishikeshAbstract:The low latency is a prime concern for large Network-on-Chips (NoCs) typically used in chip-multiprocessors (CMPs) and multiprocessor system-on-chips (MPSoCs). A significant component of overall latency is the Serialization Delay for applications which have long packets such as typical video stream traffic. To address the Serialization latency, we propose to exploit the inherent path diversity available in a typical 2-D Mesh with our two novel router architectures, Dual-path router and Dandelion router. We observe that, in a 2-D mesh, for any source-destination pair, there are two minimal paths along the edges of the bounding box. We call it XY Dimension Order Routing (DOR) and YX DOR. There are also two non-minimal paths which are non-coinciding and out of the bounding box created by XY and YX DOR paths. Dual-path Router implements two injection and two ejection ports for parallel packet injection through two minimal paths. Packets are split into two halves and injected simultaneously into the network. Dandelion router implements four injection and ejection ports for parallel packet injection. Packets are split into smaller sub-packets and are injected simultaneously in all possible directions which typically include two minimal paths and two non-minimal paths. When all the sub-packets reach the destination, they are eventually recombined. We find that our technique significantly increases the throughput and reduces the Serialization latency and hence overall latency of long packets. We explore the impact of Dual-path and Dandelion on various packet lengths in order to prove the advantage of our routers over the baseline. We further implement different deadlock free disjoint path models for Dandelion and develop a switching mechanism between Dual-path and Dandelion based on the traffic congestion
