• 한국정보과학회논문지:시스템및이론
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• 제27권5호
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• pp.450-463
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• 2000

배열 재분산은 분산 메모리 컴퓨팅 환경에서 응용 프로그램의 수행 속도를 빠르게 하기 위해 많이 사용되고 있다. 특히 GEN BLOCK간 재분산은 동적으로 부하가 변화하는 경우 최적화된 성능을 보이기 위해 필요하다. 배열 재분산에 관한 기존 연구들은 대부분 CYCLIC(N)등과 같은 정규 분산 패턴간 재분산에 대해서만 이루어져 왔다. 그러나 GEN BLOCK등과 같은 비정규 분산 패턴간 재분산에서 발생하는 메시지패싱들은 정규 분산 패턴간 재분산과는 다른 특정을 보이기 때문에 이에 대한 새로운 연구가 필요하다. 본 논문은 GEN BLOCK간 재분산에서 발생하는 메시지패싱들에 정규 분산 패턴간 재분산에서 발견되 는 규칙성은 없는 반면 공간 지역성 (spacial locality)이 존재함을 보이고, 이를 기반으로 최소 스텝 정리와 최소 크기 정리가 재분산의 성능을 향상시키는데 중요함을 증병하였으며, 기존의 리스트 스케줄링 방식에 재구성 단계(relocation phase)를 추가함으로써 최적 스케줄을 생성하는 알고리즘을 제시하였다. 마지막으로 제안한 알고리즘의 성능을 평가하기 위해 ， CRAY T3E와 IBM SP2에서 성능 평가를 수행 하였으며， 그 결과 분산 메모리 병렬 머신에서 최소 스텝 정리와 최소 크기 정리를 만족하는 스케줄이 GEN BLOCK간 재분산의 성능 향상에 중요함을 보였다.

• 품질경영학회지
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• 제17권2호
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• pp.149-157
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• 1989

A one-upper warehouse n-lower retailer inventory model is discussed. The probability distribution of demand for a given perod is independent. The inventory holding cost is proportional to the number of unsold units and the cost of shortages is proportional to the number of shortages. In the event of a shortage, units are redistributed with a cost proportional to the number of units from the retailers which are a surplus at the end of the period. The optimum stock levels are obtained and the effects of redistribution are analized.

• 한국시뮬레이션학회논문지
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• 제3권1호
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• pp.89-98
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• 1994

In this paper, a criteria for selecting an appropriate load redistribution algorithm is devised so that a fault-tolerance distributed system can operte at its optimal efficience. To present the guideline for selecting redistributing algorithms, simulation models of fault-tolerant system including redistribution algorithms are developed using SLAM II. The job arrival rate, service rate, failure and repair rate of nodes, and communication delay time due to load migration are used as parameters of simulation. The result of simulation shows that the job arrival rate and the failure rate of nodes are not deciding factors in affecting the relative efficiency of algorithms. Algorithm B shows relatively a consistent performance under various environments, although its performance is between those of other algorithms. If the communication delay time is longer than average job processing time, the performance of algorithm B is better than others. If the repair rate is relatively small or communication delay time is longer than service time, algorithm A leads to good performance. But in opposite environments, algorithm C is superior to other algorithms.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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• pp.3321-3341
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• 2014

This paper investigates the outage performance and optimization for the four-phase two-way transmission network with an energy harvesting (EH) relay. To enable the simultaneous information processing and energy harvesting at the relay, we firstly propose a power splitting-based two-way relaying protocol (PSTWR). Then, we discuss its outage performance theoretically and derive an explicit expression for the system outage probability. In order to find the optimal system configuration parameters such as the optimal power splitting ratio and the optimal transmit power redistribution factor, we formulate an outage-minimized optimization problem. As the problem is difficult to solve, we design a genetic algorithm (GA) based algorithm for it. Besides, we also investigate the effects of the power splitting ratio, the power redistribution factor at the relay, and the source to relay distance on the system outage performance. Finally, extensive simulation results are provided to demonstrate the accuracy of the analytical results and the effectiveness of the GA-based algorithm. Moreover, it is also shown that, the relay position greatly affects the system performance, where relatively worse outage performance is achieved when the EH relay is placed in the middle of the two sources.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.613-624
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• 2021

This paper analyzes the relationship between income distribution and energy consumption from a Pareto optimal approach. For this purpose, the causality relationship between electricity consumption per capita (kWh) with respect to country groups and energy consumption per capita (kg of oil equivalent) along with gross domestic product per capita was analyzed. In addition to this purpose, a Pareto analysis was conducted to determine the countries with the highest per capita national income, how much of the world total energy they consume, and whether the law of power in the energy and electricity markets exists. Finally, the impact of official development assistance provided to low-income countries by high-income countries on the low-income countries' electricity and energy consumption was analyzed. In other words, it was questioned whether pareto redistribution policies serve the purpose or not. The Engle-Granger causality approach was used in the analysis of the causality relationship between variables. Our analysis indicated that, first, the energy data of the country groups may be inadequate in revealing income inequalities. Second, the existence of Pareto law of power and global income inequality can be explained based on energy data. Finally, Pareto optimal redistribution policies to eliminate income inequality remain inadequate in practice.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.83-89
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• 2001

This paper provides a short description of the COMPASS-model which is a concept for the simulation of multiway systems. The focus of the COMPASS-model is to offer an opportunity to investigate the effects of redistribution strategies on logistic and monetary values in a system of returnable transport items (RTI). The modeling concept consists of five modules: topology, system load, distribution, redistribution, cost. It includes the integration of highly sophisticated evolutionary algorithms for the optimal solving of complex capacitated vehicle routing problems (CVRP) which are typical for RTI-systems. The results of first experiments with a COMPASS-based prototype are repeated. They reveal some basic regularities in RTI-systems.

• 산업기술연구
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• 제15권
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• pp.235-244
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• 1995

In this paper, we propose a bulk-load algorithm for $B^+-trees$, the most widely used index structures in database systems. The main characteristic of our algorithm is to simultaneously process all the keys to be placed on each $B^+-trees$ page when accessing the page. This avoids the overhead for accessing the same page multiple times, which results from applying the $B^+-trees$ insertion algorithm repeatedly. For performance evaluation, we analyze our algorithm in terms of the number of disk accesses. The results show that the number of disk accesses excluding those in the redistribution process in identical to the number of $B^+-trees$ pages. Considering that the redistribution process is an unavoidable preprocessing step for bulk-loading, our algorithm requires just one disk access per $B^+-trees$ page, and therefore turns out to be optimal. We also present performance tendancy according to the changes of parameter values via simulation.

• 한국농공학회지
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• 제27권4호
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• pp.61-67
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• 1985

This study is concerned with the optimum design of reinforced concrete frame structure with multi-stories and multi-bays by Limit State Design Method aimed to establish a synthetical optimal method that can simultaneously acomplish structural analysis and sectional desig. For optimum solution, the Successive Linear Programming known as effective to nonlinear optimization problem: including both multi-design variables and mulit-constrained condition was applied. The developed algorithm was applied to an actual structure and reached following results. 1)The developed algorithm was rvey effective converging to an optimal solution with 3 to 5 iteration. 2)An optimal solution was showed when bending moment redistribution factor a was 0.80. 3)The column was, regardless of story, controlled by the long column when unbraced, while in case of braced column, it is designed with 3 short column controlled by thrust and bending moment, and the supporting condition had little effect on the optimization results.

• 대한핵의학회지
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• 제37권5호
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• pp.278-287
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• 2003

목적: 생존심근 진단에 있어 니트로글리세린 투여 Tc-99m-MIBI 게이트 심근SPECT의 진단성능을 휴식/지연재분포 Tl-201 심근SPECT와 비교하였다. 대상 및 방법: 22명의 관상동맥질환자에서 Tl-201 휴식/디피리다몰 부하 Tc-99m-MIBI 게이트 지연재분포 Tl-201 심근SPECT를 시행하였다. 이 때 게이트SPECT 시행 후 니트로글리세린 0.6 mg을 설하투여하고 연이어 그 자리에서 게이트SPECT를 1회 더 반복 시행하였다. 환자들에게 관상동맥우회로술을 시행하고 3개월 후 게이트 심근SPECT를 추적검사로 시행하였다. 20 분절 모델을 이용하여 각 분절에서 휴식, 지연재분포, 기저상태와 니트로글리세린투여 후의 심벽운동 및 수축기비후화 등을 정량하였다. 정량화된 생존심근 예측지표들 중, (1) 휴식기 Tl-201 섭취, (2) Tl-201 지연재분포, (3) 기저상태의 수축기비후화, (4) 니트로글리세린 투여 후의 수축 기비후화, 네 가지의 예측성능을 평가하고 비교하였다. 결과: 총 100개의 분절이 분석에 포함되었으며, 이 중 66개(66%)의 분절이 재관류 후 기능 회복을 보였다. 최적 기준점인 50%를 기준으로 하였을 때, ROC 곡선 분석에서 휴식기 Tl-201 섭취와 Tl-201 지연재분포의 민감도, 특이도는 각각 79%와 44%, 그리고 82%와 44%였다. 또한 15%를 기준으로 하여, 기저상태 수축기비후화와 니트로글리세린 투여 후 수축기비후화의 민감도, 특이도는, 각각 49%, 50%와 64%, 65%였다. ROC 곡선의 AUC는 니트로 글리세린 투여 후 수축기비후화가 기저시 수축기비후화에 비하여 유의하게 높았다(p=0.004). 결론: 니트로글리세린 투여 Tc-99m-MIBI 정량적 게이트 심근SPECT는 기능이상 심근에서 기능 회복을 예측하는데 유용한 검사이다.

• 한국멀티미디어학회논문지
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• 제9권7호
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• pp.844-853
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• 2006

미래 근거리망, 도시망 및 광역망을 위해 최근에 표준화된 IEEE 802.17 레질런트 패킷링의 공정성 제어 방식은 비대칭 과부하에서 지연지터 특성을 악화시키고 대역폭 손실까지 초래하는 문제점을 갖고 이다. 본 논문은 이러한 문제를 해결하기 위해 기존 방식과 호환성을 유지하는 대역폭 재분배 기반 공정성 제어 방식을 제안한다. 제안된 방식에서 체증노드는 상단노드들의 병목링크 사용을 통제한 결과 얻어지는 병목링크의 가용 대역폭을 측정하고 대역폭이 더 필요한 상단노드의 수를 추정하여 최적 공정속도를 계산하며, 계산된 공정속도를 상단노드로 통보하여 가용 대역폭을 재분배 한다. 성능평가 결과 단 2회의 재분배 시도로 가용 대역폭의 95%를 공평하게 분배하였다.