• IEIE Transactions on Smart Processing and Computing
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• 제2권6호
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• pp.367-372
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• 2013

Cloud computing technology has been developing at an increasing expansion rate. Today most of firms are using this technology, making improving the quality of service one of the most important issues. To achieve this, the system must operate efficiently with less idle time and without deteriorating the customer satisfaction. This paper focuses on enhancing the efficiency of a conventional Genetic Algorithm (GA) for task scheduling in cloud computing using Fuzzy Logic (FL). This study collected a group of task schedules and assessed the quality of each task schedule with the user expectation. The work iterates the best scheduling order genetic operations to make the optimal task schedule. General GA takes considerable time to find the correct scheduling order when all the fitness function parameters are the same. GA is an intuitive approach for solving problems because it covers all possible aspects of the problem. When this approach is combined with fuzzy logic (FL), it behaves like a human brain as a problem solver from an existing database (Memory). The present scheme compares GA with and without FL. Using FL, the proposed system at a 100, 400 and 1000 sample size*5 gave 70%, 57% and 47% better improvement in the task time compared to GA.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.431-438
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• 2011

To ensure that equipment outages do not directly impact the reliability of the ISO-controlled grid, market participants request permission and receive approval for planned outages from the independent system operator (ISO) in competitive electricity markets. In the face of major generation outages, the ISO will make a critical decision as regards the scheduling of the essential maintenance for myriads of generating units over a fixed planning horizon in accordance with security and adequacy assessments. Mainly, we are concerned with a fundamental framework for ISO's maintenance coordination in order to determine precedence of conflicting outages. Simulated annealing, a powerful, general-purpose optimization methodology suitable for real combinatorial search problems, is used. Generally, the ISO will put forward its best effort to adjust individual generator maintenance schedules according to the time preferences of each power generator (GENCO) by taking advantage of several factors such as installed capacity and relative weightings assigned to the GENCOs. Thus, computer testing on a four-GENCO model is conducted to demonstrate the effectiveness of the proposed method and the applicability of the solution scheme to large-scale maintenance scheduling coordination problems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권4호
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• pp.1302-1320
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• 2015

In cloud, everything can be provided as a service wherein a large number of users submit their jobs and wait for their services. hus, scheduling plays major role for providing the resources efficiently to the submitted jobs. The brainwave of the proposed ork is to improve user satisfaction, to balance the load efficiently and to bolster the resource utilization. Hence, this paper roposes an Adaptive Multilevel Scheduling System (AMSS) which will process the jobs in a multileveled fashion. The first level ontains Preprocessing Jobs with Multi-Criteria (PJMC) which will preprocess the jobs to elevate the user satisfaction and to itigate the jobs violation. In the second level, a Deadline Based Dynamic Priority Scheduler (DBDPS) is proposed which will ynamically prioritize the jobs for evading starvation. At the third level, Contest Mapping Jobs with Virtual Machine (CMJVM) is roposed that will map the job to suitable Virtual Machine (VM). In the last level, VM Scheduler is introduced in the two-tier VM rchitecture that will efficiently schedule the jobs and increase the resource utilization. These contributions will mitigate job iolations, avoid starvation, increase throughput and maximize resource utilization. Experimental results show that the performance f AMSS is better than other algorithms.

• 한국통신학회논문지
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• 제31권5A호
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• pp.469-474
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• 2006

본 논문에서는 High Speed Data Packet Access(HSDPA) 시스템의 평균 sector throughput 분석 방법을 개발하였다. 제안하는 성능 분석 방법은 Adaptive Modulation and Coding(AMC)와 scheduling 기법, multi-code 전송의 영향을 반영할 수 있으며, link budget을 응용한 간단한 계산 과정들을 통해, HSDPA의 성능을 분석할 수 있다. 일반적으로, link budget은 셀 coverage를 산출하는 목적으로 사용되었으나, 본 논문에서는 AMC가 적용되는 CDMA 시스템 환경에서 특정 위치에 있는 사용자의 C/I를 계산할 수 있도록 변형하였다. 또한, 개발된 분석 방법을 활용하여, scheduling 기법과 multi-code 전송이 HSDPA 시스템 성능에 미치는 영향을 분석하였다.

• 전자공학회논문지S
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• 제34S권11호
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• pp.25-33
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• 1997

The end-to-end rate-based control mechanism is used for the flow control of the ABR service to allow much more flexibility in ATM switching system. To accommodate the ABR service effciently many algorithms such as EFCI, EPRCA, ERICA, and CAPC2 have been proposed for the switch algorithm. ABR cells and related RM cells are received at the ATM switch fabric transparently without any processing. And then cells received from the traffic source are queued in the ABR buffer of switching system. The ABR buffer usually has some thresholds for easy congestion control signal transmission. Whatever we use, therefore, these can be many ABR traffic control algorithms to implement the ABR transfer capability. The genertion of congestion indicate signal for ABR control algorithms is determined by ABR buffer satus. And ABR buffer status is determined by ABR cells transfer ratio in ATM switch fabrics. In this paper, we presented the functional structures for control of the ABR traffic capability, proposed the readout scheduling, cell slot allocation of output link and the buffer allocation model for effective ABR traffic guranteeing with considering CBR/VBR traffics in ATM switch. Since the proposed readout scheduling scheme can provide more avaliable space to ABR buffer than existing readout scheduling scheme, generation rate of a SEND signal, that is, BCN signal in destination node can be increased for ABR call connection. Therefore, the proposed scheme, in this paper, can be appropriate as algorithm for effective ABR traffic service on output link of ATM switching node.

• 정보처리학회논문지C
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• 제11C권6호
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• pp.863-870
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• 2004

최근들어 UMTS(Universal Mobile Telecommunication System)는 3세대 무선망의 표준으로 인식되고 있고 DSCH(Down-link Shared Chanel)는 UMTS에서 매우 효율적인 다중화 방안으로 고려되고 있다. 그러므로 UMTS에서의 DSCH를 위한 효과적인 패킷스케줄링 알고리즘 개발에 대한 연구가 필수적이다. 본 논문은 UMTS의 DSCH를 위한 개선된 패킷스케줄링 알고리즘에 대하여 기술한다. 이 알고리즘은 최대 링크 이용율을 위하여 이동호스트채널상태를 고려하며, 동시에 장기적으로 공정성을 얻기 위해 3등급 트래픽에서의 지연 한계치와 4등급 트래픽의 처리율을 함께 이용한다. 알고리즘의 타당성을 보이기 위하여 PARSEC을 이용한 모의실험을 수행하였다. 모의실험 결과는 이 알고리즘이 무선링크 이용율과 공정성 두 가지 측면에서 적적한 타협(trade-off)을 통하여 개선된 결과를 얻을 수 있음을 보여준다.

• 한국통신학회논문지
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• 제38A권6호
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• pp.528-534
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• 2013

센서 네트워크에서 기본적으로 고려되어야 하는 것은 센서 노드의 에너지 소모 문제이다. 이를 해결하기 위해 많은 연구들이 진행되어 왔지만 에너지 소모 문제와 더불어 트레이드오프 관계를 갖는 지연 문제도 간과할 수 없는 부분이다. 본 논문은 생체시스템을 모방하여 무선 센서망에서 에너지의 소모와 지연시간을 줄이기 위한 BISA(Bio-inspired Scheduling Algorithm)를 제안한다. BISA는 에너지 효율성이 높은 라우팅 경로를 탐색하고 다중채널을 이용하여 데이터 전송의 경로를 다중화하여 데이터 전송을 위한 에너지 소모와 지연시간을 최소화한다. 모의실험을 통해 제안한 방식이 효율적으로 에너지를 소모함과 동시에 요구지연시간을 보장함을 확인한다.

• 전기학회논문지
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• 제65권4호
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• pp.547-554
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• 2016

Analyze the customer daily load patterns, be used to determine the optimal charging and discharging schedule which can minimize the electrical charges through the battery energy storage system(BESS) installed in consumers is an object of this paper. BESS, which analyzes the load characteristics of customer and reduce the peak load, is essential for optimal charging and discharging scheduling to save electricity charges. This thesis proposes optimal charging and discharging scheduling method, using particle swarm optimization (PSO) and penalty function method, of BESS for reducing energy charge. Since PSO is a global optimization algorithm, best charging and discharging scheduling can be found effectively. In addition, penalty function method was combined with PSO in order to handle many constraint conditions. After analysing the load patterns of target BESS, PSO based on penalty function method was applied to get optimal charging and discharging schedule.

• JSTS:Journal of Semiconductor Technology and Science
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• 제16권6호
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• pp.808-816
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• 2016

As the number of CPU/GPU cores and IPs in SOC increases and applications require explosive memory bandwidth, simultaneously achieving good throughput and fairness in the memory system among interfering applications is very challenging. Recent works proposed priority-based thread scheduling and channel partitioning to improve throughput and fairness. However, combining these different approaches leads to performance and fairness degradation. In this paper, we analyze the problems incurred when combining priority-based scheduling and channel partitioning and propose dynamic priority thread scheduling and adaptive channel partitioning method. In addition, we propose dynamic address mapping to further optimize the proposed scheme. Combining proposed methods could enhance weighted speedup and fairness for memory intensive applications by 4.2% and 10.2% over TCM or by 19.7% and 19.9% over FR-FCFS on average whereas the proposed scheme requires space less than TCM by 8%.

• 한국항행학회논문지
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• 제15권4호
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• pp.517-522
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• 2011

위성항법 보정 시스템은 형태에 따라 지역보정 시스템과 광역 보정 시스템으로 나뉜다. 광역보정 시스템은 지역 보정시스템에 비해 시스템 구조가 복잡하며, 방송 메시지의 종류와 양이 많다. 또한 제한된 전송속도로 인해 사용자의 정확성과 무결성을 유지하기 위해서는 효율적인 메시지 스케쥴링이 필요하다. 현재 광역보정시스템에서는 30여 가지의 메시지가 방송되며 메시지 타입에 따라 업데이트 주기가 다르다. 본 논문에서는 메시지 스케쥴링 알고리듬을 적용하고 시뮬레이션을 통하여 성능을 분석하였다. 시뮬레이션 결과 모든 메시지 타입에서 최대 업데이트 주기 요구 조건을 만족시킴을 확인할 수 있었다.