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Hybrid hierarchical network design scheme with wavelength conversion
Get PDFThis paper proposes a hybrid hierarchical network design scheme with wavelength conversion (H2NDS) to design a low-delay network by integrating a conventional IP network and an optical network with wavelength conversion devices. In H2NDS, the network is divided into multiple domains, and wavelength converter devices and router devices are located at the relay node, an interconnection point between these domains. H2NDS is formulated as an integer linear programming problem to the sum of the delay of all end-to-end paths (delay) with constraint of the number of wavelengths in the optical network. Each end-to-end path selects the optimal relay node and selects either the router or wavelength converter devices to minimize the delay. The evaluation results showed that H2NDS significantly improved the delay performance compared to the benchmark model in which all end nodes belong to the nearest relay node, achieving a maximum reduction of 77.9 %.journal articl
Dynatune: Dynamic Tuning of Raft Election Parameters Using Network Measurement
Get PDFRaft is a leader-based consensus algorithm that implements State Machine Replication (SMR), which replicates the
service state across multiple servers to enhance fault tolerance. In Raft, the servers play one of three roles: leader, follower, or candidate. The leader receives client requests, determines the processing order, and replicates them to the followers. When the leader fails, the service must elect a new leader to continue processing requests, during which the service experiences an out-of-service (OTS) time. The OTS time is directly influenced by election parameters, such as heartbeat interval and election timeout. However, traditional approaches, such as Raft, often struggle to effectively tune these parameters, particularly under fluctuating network conditions, leading to increased OTS time and reduced service responsiveness. To address this, we propose Dynatune, a mechanism that dynamically adjusts Raft’s election parameters based on network metrics such as round-trip time and packet loss rates measured via heartbeats. By adapting to changing network environments, Dynatune significantly reduces the leader failure detection and OTS time without altering Raft’s core mechanisms or introducing additional communication overheads. Experimental results demonstrate that Dynatune reduces the leader failure detection and OTS times by 80% and 45%, respectively, compared with Raft, while maintaining high availability even under dynamic network conditions. These findings confirm that Dynatune effectively enhances the performance and reliability of SMR services in various network scenarios.conference pape
Response and regulation of circadian rhythms by external stimulus
Get PDF豊橋技術科学大学博士（工学）doctoral thesi
Development of vibration control system using pulley mechanisms equipped with nonlinear viscous dampers
Get PDF豊橋技術科学大学博士（工学）doctoral thesi
Who is Kan Bun Kai? From the Taiwan Independence Movement in Japan to Popular Novelist in Japan
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Digital Service Substitution and Social Networks: Implications for Sustainable Urban Development
Get PDFConsidering the rapid integration of digital services into daily life, it is crucial to analyze the impacts of the substitutability of physical services with digital alternatives. Limited studies have been conducted to investigate the relationship between service substitution and social networks and assess their impact on urban structure. Therefore, this study fills the gap by investigating how digital service substitution and social networks influence residential location choices and urban structure, aiming to support future sustainable urban modeling and planning tools. The study, through a comprehensive analysis incorporating cluster analysis, factor analysis, and binomial logistic regression on a web-based questionnaire survey (n = 6210), finds that socio-demographic factors significantly influence digital alternatives, and that digital service substitution and social networks impact sustainable urban structure. Younger individuals showed significantly higher adoption of digital alternatives, with age negatively associated with relocation likelihood. In urban areas, each additional year of age reduces the likelihood of relocation by approximately 4.4%, and individuals with high shopping substitution are 3.12 times more likely to consider relocation. These findings suggest that urban planners and policymakers to balancing physical and digital service provision to maintain a higher quality of life aligned with the SDGs and ensure sustainable urban development.journal articl
Re-examination of “Lexicalized” Manner and Result Meaning Components of Verbs in English Resultative Constructions
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