• Journal of KIISE:Computer Systems and Theory
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• v.34 no.7
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• pp.304-318
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• 2007

Grid computing is a service that share geographically distributed computing resources through high speed network. In this paper, we propose hybrid scheduling scheme which considers not only meta-scheduling scheme to distribute the job between the nodes of grid computing system but also the job scheduling to distribute the job within the local nodes. According to the number of processors needed and expected execution time, the job with high priority is allocated to job queue while the one with low priority and remote job are allocated to backfill queue. We evaluate the proposing scheme through the various experiments and the results show that the utilization of grid computing system increases and the job slowdown decreases.

• Journal of KIISE:Computer Systems and Theory
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• v.30 no.12
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• pp.736-748
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• 2003

Dynamic voltage scaling(DVS), which adjusts the clock speed and supply voltage dynamically, is an effective technique in reducing the energy consumption of embedded real-time systems. The energy efficiency of a DVS algorithm largely depends on the performance of the slack estimation method used in it. In this paper, we propose novel DVS algorithms for periodic hard real-time tasks based on an improved slack estimation algorithm. Unlike the existing techniques, the proposed method can be applied to most priority-driven scheduling policies. Especially, we apply the proposed slack estimation method to EDF and RM scheduling policies. The experimental results show that the DVS algorithms using the proposed slack estimation method reduce the energy consumption by 20∼40 % over the existing DVS algorithms.

• Convergence Security Journal
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• v.20 no.5
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• pp.41-52
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• 2020

This paper implements a priority algorithm for active response to security event risk, and implements an event scheduler that performs efficient event processing based on this. According to the standards that have global standards such as CVE and CVSS, standards for scoring when security events are executed are prepared and standardized so that priorities can be more objectively set. So, based on this, we build a security event database and use it to perform scheduling. In addition, by developing and applying the security event scheduling priority algorithm according to the situation of security events in Korea, it will contribute to securing the reliability of information protection and industrial development of domestic or ganizations and companies.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.61-69
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• 2021

On-demand broadcast is an effective data dissemination technique in mobile computing environments. This paper explores the issues for scheduling multi-data queries in on-demand broadcast environments, and proposes a new broadcast scheduling scheme named CASS. The proposed scheme prioritizes queries by reflecting the characteristics of multi-data queries, and selects the data that has not been broadcast in the query for the longest time as the broadcast data according to the query priority. Simulation is performed to evaluate the performance of CASS. The simulation results show that the proposed scheme outperforms other schemes in terms of the average response time since it can show highly desirable characteristics in the aspects of query data adjacency and data conflict rate.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06b
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• pp.389-392
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• 2010

실시간 임베디드 시스템에서 멀티미디어 시스템 같은 빠른 응답성을 요구하는 시스템이 존재 할 수 있다. 현재 EDF, RM 알고리즘의 경우 각각 마감시간, 수행 주기 시간에 의해서 우선순위가 선정되고 수행된다. 그러나 시스템 상에 실시간 프로세스 외에 다양한 프로세스가 존재할 수 있다. 본 논문에서는 마감 시간과 프로세스의 기본 우선순위를 고려하여 새로운 우선순위를 이용하며, 전체 프로세스들이 마감 시간내에 스케줄링 가능하고 문맥교환에 의한 오버헤드에 의해 마감시간을 넘어가지 않을 경우 각 프로세스들에게 타임 슬라이스를 할당하여 수행할 수 있도록 하여 기존 알고리즘들 보다 응답성을 향상시키는 기법을 제시한다.

• Journal of Internet Computing and Services
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• v.9 no.1
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• pp.137-143
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• 2008

In ubiquitous environment the multi-agent system is effective for providing intelligent services. In this paper we introduce a new scheduling service model for improving the communication performance in the multi-agent system. It is achieved by assigning a priority to the message according to the weight of formalized ACL message and the number of messages exchanged between the agents. An experiment reveals that the proposed approach allows smaller processing time per message and turnaround time than the scheduling with the existing JADE platform. Moreover, the proposed scheme allows a scalable messaging system.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.832-834
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• 2005

임베디드 시스템은 범용 컴퓨팅 시스템과 달리 자신을 포함하고 있는 기기에 부과된 특정 목적의 컴퓨팅 작업만을 수행한다. 이 시스템을 제어하기 위해서 운영체제가 필요로 하며, 임베디드 환경에서는 신뢰성과 정확성을 요하는 부분이 많기 때문에 실시간 운영체제를 필요로 한다. Real-Time kernel을 기반으로 하는 MicroC/OS-II는 수많은 용도로 사용되고 있지만 task 사용에 한계가 있다. 이 논문에서 제안하는 스케줄링은 task의 생성 수를 늘려주지만, 이 경우 task간의 우선순위 설정이 어려워진다. 이 문제 해결을 위해서 task들의 우선순위 결정은 deadline을 이용하여 3레벨로 나눈다. 3레벨로 나누어지면 task의 수가 증가해도 개발자는 task들을 레벨에 맞게 설정하면 task 관리로 인하여 생기는 문제를 줄일 수 있으며, 효율적인 스케줄링을 가능하게 한다.

• The KIPS Transactions:PartC
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• v.10C no.1
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• pp.45-50
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• 2003

Guaranteed Frame Rate (GFR) service category is one of the most recent ATM service categories. The GFR specification was recently finalized by the ATM Forum and is expected to become an important service category which can efficiently support TCP/IP traffic in ATM network. In GFR switch implementation, it is important to guarantee MCR (minimum cell rate) and improve fairness. In this paper, we propose a new scheduling algorithm for the GFR service. Proposed algorithm provides priority to VC (virtual circuit)s and high Priority given to a VC which has fewer untagged cells in buffer. High priority VCs are serviced before low priority VCs. Proposed algorithm can guarantee MCR and improve fair sharing of the remaining bandwidth between GFR VCs. From computer simulation results, we demonstrate the proposed scheduling algorithm provide much better performance in TCP goodput and fairness than previous schemes.

• Journal of the Korea Society of Computer and Information
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• v.18 no.8
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• pp.9-15
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• 2013

As the resources of cloud computing are essentially heterogeneous and jobs have various characteristics, resource allocation to jobs is one of important problems. We define this issue as a multi-criteria decision-making problem. This paper proposes a priority-based job scheduling algorithm based on analytic hierarchy process (AHP). On the first step, jobs are classified based on their preferences. On the second step, response time, system utilization, and load becomes decision criteria based on the AHP algorithm. Jobs are allocated to adequate resources through their priorities that are calculated by the AHP algorithm. Through analysis and experiment of the proposed algorithm, we are to confirm that the scheme can schedule jobs as well as utilize its resource efficiently.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.39 no.6
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• pp.36-46
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• 2002

This paper proposes an integrated scheduling mechanism for embedded system with real-time web server to meet the characteristics of real time task. The proposed scheduling mechanism may solve the so-called priority inversion problem in scheduling between urgent web requests and tasks with low priorities. The priority inversion problem happens because of operating two independent schedulers, web scheduler and operating system scheduler in a system without considering the requirements of each other. In the proposed mechanism, two schedulers are integrated in an operating system and the integrated scheduler schedules tasks for urgent web requests with real time characteristics and other application tasks together. Since all tasks are scheduled by one unified scheduler that knows the characteristics of tasks, the tasks are scheduled with their absolute priorities and thus the priority inversion problem can be eliminated. The performance is measured on a prototype embedded system with the proposed algorithm.