• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.556-559
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• 2007

하나의 시스템을 다수의 사람들이 작업을 할 경우 한정된 자원을 각각의 작업에 효율적으로 배분하기 위하여 작업관리 시스템을 이용한다. IBM 시스템은 작업관리 시스템으로서 주로 LoadLeveler를 사용하고 있다. 작업관리 시스템은 작업을 처리할 수 있는 여러가지의 큐를 가지고 있으며, 큐는 시스템의 특성과 구성 그리고 사용자 작업의 패턴에 따라서 설계되어진다. 본 논문에서는 LoadLeveler에서 작업을 실행할 때 긴급한 작업을 우선적으로 처리할 수 있는 큐를 만들기 위하여 preemption 기능을 이용하여 구성하고, 해당 큐로 작업을 선점하여 실행하면서 각각 작업들의 메모리 사용 변화와 그에 따른 작업 처리 성능을 분석하고 방법을 연구하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.269-272
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• 2008

하나의 시스템을 다수의 사람들이 동시에 작업을 할 경우 한정된 자원을 각각의 작업 요구에 효율적으로 배분하기 위하여 작업관리 시스템을 사용한다. IBM 시스템은 작업관리 시스템으로서 주로 LoadLeveler를 사용하고 있다. 작업관리 시스템은 자원을 할당 받아 작업을 처리할 수 있는 여러 가지의 큐를 가질 수 있으며, 이러한 큐는 시스템의 특성과 구성 그리고 사용자 작업의 패턴에 따라서 설계되어진다. 본 논문에서는 LoadLeveler에서 작업을 실행할 때 자원을 미리 예약하여 실행할 수 있는 reservation과 긴급한 작업을 우선적으로 처리할 수 있게 해주는 preemption 기능을 적용한 클래스를 만들어 작업을 실행하면서 각각 작업들의 메모리 사용 변화와 그에 따른 작업 처리 성능을 분석 연구하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.585-588
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• 2008

센서 네트워크에 사용되는 운영체제 중 TinyOS는 Event-driven 방식이며 Component 기반의 센서 네트워크 운영체제이다. 이러한 TinyOS는 일단 태스크가 시작되면 마칠 때까지 다른 태스크가 기다려야하는 비선점형(Non-preemption) 방식이다. 최근 연구에서 TinyOS의 빠른 반응성을 위해 선점(Preemption)할 수 있는 기능이 추가되었다. 그러나 프로그래밍할 때 우선순위를 미리 주어줘야 하는 단점이 있다. 본 논문에서는 좀 더 유연하게 우선순위를 변경할 수 있는 방식을 제안하고자 한다.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.945-951
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• 2022

The major objective of this research is to evaluate performance of improved intersections for response time to emergency vehicle preemption. Smart technologies have been introduced to civil infrastructure systems for resilient communities. The technologies need to evaluate their effectiveness and feasibility to confirm their introduction. This research focuses on the performance of emergency vehicle preemption, represented by response time, when smart intersections are introduced in a community. The response time is determined by not only intersections but also a number of factors such as traffic, distance, road conditions, and incident types. However, the evaluation of emergency response has often ignored factors related to emergency vehicle routes. In this respect, this research synthetically analyzes geospatial and incident data using each route of emergency vehicle and conducts before-and-after evaluations. The changes in performance are analyzed by the impact of smart intersections on response time through Bayesian regression models. The result provides measures of the project's performance. This study will contribute to the body of knowledge on modeling the impacts of technology application and integrating heterogeneous data sets. It will provide a way to confirm and prove the effectiveness of introducing smart technologies to our communities.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.171-180
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• 2004

CDP(handoff Call Dropping Probability) and CBP(new Call Blocking Probability) have been used as two important call level QoS parameters in cellular mobile communications. But, many methods to reduce CDP without considering CBP have been studied, and hand-off call priority scheme has been introduced. But the use of hand-off call priority scheme increases CBP and decreases channel utilization rate depending on the number of reserved channel for priority. In this paper, we propose a CAC(Call Admission Control) algorithm with overflow and preemption to solve the problem caused by considering CDP and CBP in calculation of the number of channel reserved. The problem is the increase of CDP as the traffic load increases. In our CAC algorithm, hand-off call is permitted to use(overflow) unreserved and unused channel if there is no reserved and unused channel, and new call is permitted to use(preemption) the channel overflowed by hand-off call if there is no unreserved and unused channel. This mechanism of calculation of the number of reserved channel and CAC algorithm is expected to increase channel utilization rate, and can be applied to media-based QoS provision in cellular mobile communications.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.4
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• pp.443-454
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• 1999

최소 여유시간 우선(Least-Laxity-First)스케쥴링 알고리즘은 여유시간이 작은 태스트가 높은 우선순위를 갖는 동적 우선순위 스케줄링 방법으로서 단일프로세서 시스템에서 최적임이 증명되었다. 그러나, 이 알고리즘은 최소 여유시간을 가진 태스크가 여러 개 존재하여 여유시간 충돌이 발생한 경우 이 태스크들 간에 빈번한 문맥교환이 발생하게 되는 문제점이 있어 실용적이지 못하다. 본 논문에서 제한하는 최소 여유시간 우선 기반의 최소선점을 갖는 스케줄링 알고리즘(Least-Laxity-First with Minimum Preemption 또는 LLF/MP)은 여유시간이 충돌했을 때에 문맥교환을 최소화함으로써 최소 여유시간 우선 스케줄링 알고리즘의 단점을 해결하였다. LLF/MP 스케줄링 알고리듬은 불필요한 문맥교환을 줄임으로써 시스템 오버헤드로 인한 시스템의 성능 저하를 방지할 수 있고 보다 많은 시스템 자원을 예측 불가능한 비주기적 태스크에게 할당할수 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.9
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• pp.1906-1914
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• 2012

In this paper, relative service differentiation in JET based optical burst-switched networks with deflection routing is presented. It differs from conventional schemes in that it tries to make the loss rate of high class bursts as low as possible while maintaining the desired proportional ratio between the high class bursts and low class bursts. Strategies applied to it are dynamic wavelength allocation and the preemption which are combined to deflection routing. With dynamic wavelength allocation, the number of wavelengths allocated to high class bursts are dynamically changed. Preemption which gives more preference to high class bursts is also applied to decrease its loss rate. To lower the loss rate, deflection routing is applied for any kind of traffic. With those strategies, the suggested scheme shows desired properties that the loss rate of high class traffic is as lowered as possible. A queueing model for the scheme is developed to approximate loss ratio and the numerical results show that the proposed scheme provisions relative service differentiation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.137-154
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• 2019

This study analysed the center control emergency vehicle preemption[EVP] test result on the 1.782 km section around Gangbuk Fire Station. The pros and cons between center control and site control EVP was compared through the review of existing research. The test site was selected based on the higher link speed for choosing low congested area and 4 to 6 lane road. EVP operates green extension under the estimated arrival time to each intersection. This study is about EVP system field application and its evaluation by analyzing EVP operation result with the emergency vehicle's trace, GPS data. The impact on the surrounding traffic was analysed in delay from the queue length survey. Analysis showed the decrease in averge travel time 41.81%, but the increase in delay of surrounding traffic slightly. It is expected that EVP can be applied to the expanded area by researching EVP compensation scheme.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.2
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• pp.39-47
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• 2012

In this paper, we have developed the system of emergency vehicle preemption signal control based on UTIS(Urban Traffic Information System) which have been deployed and operated in the national capital area. It considered the turning direction(through or left turn) of emergency vehicle at the signalized intersection in order to provide the consecutive progression of emergency vehicle and minimize the control delay of passenger cars. we adopted several EVP control modes such as phase insertion and phase adjustment mode. Also, we evaluated the possibility of field implementation via simulation analysis using CORSIM RTE(Run Time Extension) based HILS(Hardware In the Loop Simulation). We expect that the result of this research contribute to providing the right-of-way to emergency vehicle in this country.

• Journal of the Institute of Convergence Signal Processing
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• v.11 no.4
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• pp.345-353
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• 2010

A general solution in global self-position location of robot is to generate multiple hypothesis in self-position of robot, which is to look for the most positive self-position by evaluating each hypothesis based on features of observed landmark. Markov Localization(ML) or Monte Carlo Localization(MCL) to be the existing typical method is to evaluate all pairs of landmark features and generated hypotheses, it can be said to be an optimal method in sufficiently calculating resources. But calculating quantities was proportional to the number of pairs to evaluate in general, so calculating quantities was piled up in wide environments in the presence of multiple pairs if using these methods. First of all, the positive and promising pairs is located and evaluated to solve this problem in this paper, and the newly locating method to make effective use of calculating time is proposed. As the basic method, it is used both RANSAC(RANdom SAmple Consensus) algorithm and preemption scheme to be efficiency method of RANSAC algorithm. The calculating quantity on each observation of robot can be suppressed below a certain values in the proposed method, and the high location performance can be determined by an experimental on verification.