높은 처리율과 에너지 효율성을 위한 무선AP의 시간 윈도우 스케줄링 기법

학위논문(석사) - 한국과학기술원 : 전산학과, 2012.8, [ iv, 40 p. ]Wi-Fi interface is one of the predominant energy consumers in Wi-Fi stations. Despite many researches on Wi-Fi energy management, energy wastage of Wi-Fi stations resulting from network contention among mul-tiple access points (APs) has not been widely investigated. The network contention usually occurs in two situa-tions: among an AP’s associated stations and among stations associated with multiple APs. In this paper, we focus on the latter situation. We analyze the network contentions occur among multiple APs, and show that Wi-Fi power save mode performance could be severely affected by network contentions. In order to overcome the network contention problem, we propose a scheduling policy, Tame, to assign multiple access points into different subclusters, in each of which none of the access points have network contentions and data can be transmitted simultaneously without collision. Access points assigned into different subclusters cannot transmit data at the same time, otherwise those APs will have network contentions and energy of Wi-Fi stations can be wasted. To avoid the data transmission time overlapping, we need to turn off the MORE_DATA flag embedded in the data packets so that the APs can make the Wi-Fi stations go to sleep. Every subcluster is assigned to the same time slot to transmit data to guarantee the network throughput fairness. To further enlarge the throughput, we make use of maximum independent set algorithm and set permutation algorithm to enlarge the number of access points assigned to each subcluster and reschedule the beacon time, thus the overall system’s average throughput is enhanced. Since only during the assigned transmission time will the associated Wi-Fi stations get data and in the other time the stations keep sleeping, the Wi-Fi stations’ energy consumption is reduced dramatically. At the same time, we study the related work Sleepwell and propose Tame strategy. Compared with Sleepwell, Tame improves the throughput. We...한국과학기술원 : 전산학과

Design and Implementation of Information Management Tools for the EDISON Open Platform

We have developed an information management tool for the EDISON (EDucation-research Integration through Simulation On the Net) open platform. EDISON is, at present, a web-based simulation service for education and research in five computational areas, namely, nanophysics, fluid dynamics, chemistry, structural dynamics, and computer aided optimal design. EDISON open platform consists of three tiers: EDISON application framework, EDISON middleware, and EDISON infra resources. It provides web portals for education and research in areas, such as computational fluid dynamics, computational chemistry, computational nanophysics, computational structural dynamics, and computer aided optimal design along with user service.In this paper, the main purpose is to test the normal operation of the release version of EDISON Open-Platform. This management tool has been implemented using the RESTful API designed in EDISON middleware. The focus is to check the operation between the middleware and the infrastructure. Suggest tool include User management, Simulation and Job management and Simulation software (i.e. Solver) test. Finally, it is meaningful to develop a management tool is not support in other web-based online simulation service

A Simulation-Provenance Data Management System for Efficient Job Execution on an Online Computational Science Engineering Platform

In the past few years an online simulation service platform (named EDISON) has been applauded by several computational science and engineering communities in several countries. Though armed with multiple computing clusters and high-end storage resources, the platform has suffered from handling a huge amount of CPU-/IO-bound simulations that are most duplicated. Such intense simulations are normally admitted with no duplicate elimination and thus can adversely affect the performance of the platform. To address this performance concern, we propose a novel system, termed SUPERMAN, to seamlessly record and retrieve the provenances of previously executed simulations, and so prevent users from initiating duplicate and/or similar simulations using the limited computing resources. The system collects the simulation provenances based on a variant of a de-facto standard form, thereby offering interoperability. Based on the stored provenances, the system can provide useful simulation run statistics for users that need assistance. SUPERMAN also applies a hash-based duplicate elimination technique, resulting in making more efficient simulations on the platform. Finally, we show that the proposed proposed system could remove slightly over half of duplicate simulations on a variety of simulation software while obtaining about overall elapsed time savings of 30% and queuing time savings of 25%