• 통합자연과학논문집
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• 제17권2호
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• pp.43-51
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• 2024

Jung et al.(2015) suggest the two-phase warranty model, which is a general type of warranty model. Under the two-phase warranty, the warranty period is divided into two intervals, one of which is for renewing replacement warranty, and the other is for minimal repair warranty. And warranty policies play a very important role in product marketing. In this paper, we suggest the optimal warranty policy for free extended two-phase warranty. To determine the optimal warranty period, we adopt the expected profit per unit product. So, the expressions for the total expected cost, the sale price and the expected profit per unit product from the manufacturer's point of view are derived. Also, we discuss the optimal warranty period and the numerical examples are provided to illustrate the proposed the warranty policy.

• 품질경영학회지
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• 제35권1호
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• pp.20-23
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• 2007

A generalized spare ordering policy is treated in this paper. If the operating unit fails before a scheduled ordering time an expedited order is placed at the failure time instant, otherwise a regular order for a spare is placed at the scheduled time. The original unit is replaced when the ordered spare is delivered. The lifetime, regular and expedited lead times have general distributions. The problem is to find the optimum ordering time which minimizes the expected cost rate including the observation, ordering, uptime and down-time costs. Some properties regarding the optimal policy are derived. To explain the spare ordering policy a numerical example is also included.

• 실천공학교육논문지
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• 제11권2호
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• pp.239-249
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• 2019

현재 직업능력개발훈련에 대한 재정 지원은 NCS 직종 분류에 따라 설정된 NCS 기준 단가에 따라 집행되고 있다. 이러한 기준단가 제도는 훈련분담금-지원금 제도가 운영되는 경우 그에 필요한 행정 부담을 경감시켜주는 장점을 갖고 있다. 본 논문에서는 현재 NCS 기준단가가 훈련과정별 수강료를 기준으로 함에 따라 직업훈련 정책의 사회통합적 기능을 왜곡시킬 수 있음을 지적하였다. 앞으로 합리적 개선 방안 모색을 위한 기초로서, 훈련기관에서 책정하는 훈련과정별 수강료에 어떤 요인들이 영향을 미치는지 분석하였다. 그 결과 실제로 훈련기관의 독점적 성격이나 훈련참여자의 높은 지불의사가 수강료에 영향을 미침을 확인할 수 있었다. 따라서 향후 정부의 직업능력개발훈련에 대한 재정지원에서 이러한 영향을 제거하고 실제 훈련공급비용에 가까운 지원이 이뤄지도록 함으로써 훈련정책이 사회적 통합성 제고에 기여하도록 해야 할 것이다. 더 나아가 근본적으로 모든 훈련과정의 정확한 훈련공급비용을 보전해 줄 수 없다면 정부의 정책적 판단을 중심으로 하는 지원 기준 마련이 필요하다.

• 농촌계획
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• 제21권2호
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• pp.149-162
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• 2015

Korean sixth industrialization policy is similar to that of Japanese such as goal of policy, setup and promotion method of specific policy projects as it benchmarked a Japanese case. First of all, the certification systems of both countries, the most representative policy, are very alike that the governments officially certificate management bodies, prepare the ground for continuous sixth industrialization, devide intermediate support organization into the central unit and regional unit, and have the function of support and control of sixth industrialization management bodies. Furthermore, both countries create fund for sixth industrialization as an investment support policy, and push forward with the phased support policy businesses such as individual support and connected support for management bodies. However, there are some differences between certification systems of both countries such as process-oriented or result-oriented for certification, subtle differences of the role in support organization, and the range and rate of support.

• 대한임베디드공학회논문지
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• 제13권5호
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• pp.269-277
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• 2018

NAND flash memory has widely been used because of non-volatility, low power consumption and fast access time. However, it suffers from inability to provide update-in-place and the erase cycle is limited. The unit of read/write operation is a page and the unit of erase operation is a block. Moreover erase operation is slower than other operations. We proposed the Adaptive Garbage Collection (called "AGC") policy which focuses on not only reducing garbage collection process time for real-time guarantee but also wear-leveling for a flash memory lifetime. The AGC performs better than Cost-benefit policy and Greedy policy. But the AGC does not consider the operation characteristics. So we proposed the Advanced Adaptive Garbage Collection (called "A-AGC") policy which considers the page write operation count and block erase operation count. The A-AGC reduces the write operations by considering the data update frequency and update data size. Also, it reduces the erase operations by considering the file fragmentation. We implemented the A-AGC policy and measured the performance compared with the AGC policy. Simulation results show that the A-AGC policy performs better than AGC, specially for append operation.

• 한국산학기술학회논문지
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• 제13권4호
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• pp.1880-1888
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• 2012

본 연구에서는 지구단위 설계시 교통부문에서 다양한 도시설계 및 교통정책의 적용에 따른 교통량 패턴 효과를 분석해보고자 하였다. 이를 위해 가상네트워크(Toy Network)를 설정하고 토지이용패턴과 교통정책을 접목한 19개의 시나리오를 가정한 후 교통수요 예측 프로그램인 EMME3를 이용하여 교통량 배정량을 산정하고 비교하였다. 그 결과 총 교통량이 가장 많이 감소한 정책은 지구의 중간부를 개발하면서 동시에 내부의 2차로 도로는 차량 통행을 금지시키고 보행자 천국을 만드는 것이었다. 총 통행량이 가장 많이 발생된 정책은 균등개발을 하며 지구의 중간부에 공동 주차장을 만드는 것이었으며 내부 연도 주민에게 가장 불리한 정책은 지구 중심의 한 개 존만을 개발하는 것임을 확인할 수 있었다.

• International Journal of Reliability and Applications
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• 제12권2호
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• pp.131-143
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• 2011

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• 한국신뢰성학회지:신뢰성응용연구
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• 제13권4호
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• pp.229-239
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• 2013

This paper reports a manner to use a Bayesian approach to derive the optimal replacement policy. In order to produce a system with minimal repair warranty, a replacement model with the extended warranty is considered. Within the warranty period, the failed system is minimally repaired by the manufacturer at no cost to the end-user. The failure time is assumed to follow a Weibull distribution with unknown parameters. The expected cost rate per unit time, from the end-user's viewpoints, is induced by the Bayesian approach, and the optimal replacement policy to minimize the cost rate is proposed. Finally, a numerical example illustrating to derive the optimal replacement policy based on the Bayesian approach is described.

• International Journal of Reliability and Applications
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• 제10권1호
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• pp.33-42
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• 2009

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• 산업경영시스템학회지
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• 제33권2호
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• pp.170-175
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• 2010

Maintaining a complex repairable system can be achieved by repairing, replacing, or any other activities. This paper proposes a joint optimization policy that is composed with ordering and replacing under minimal repair for the complex system. For this purpose, we derive the expected cost due to the minimal repair, ordering, downtime, inventory costs, and salvage value of units that follow generally distribution. Some properties about the optimum ordering policy that are suggested for our purpose shows that the optimum ordering policy minimizing the expected cost is either one of the two typical policies : (1) the original unit is replaced as soon as the ordered spare is delivered, or (2) the delivered spare is used as inventory part until the original unit fails.