• Management Science and Financial Engineering
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• 제11권1호
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• pp.1-24
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• 2005

The results of a study of the coordination effect in stocking and promotional markdown policies for a supply chain consisting of a retailer and a discount outlet (DCO) are reported here. We assume that the product is sold in two consecutive periods: the Normal Sales Period (NSP) and the subsequent Promotional Markdown Sales Period (PSP). We first study an integrated supply chain in which managers in the two periods design a common system so as to jointly decide the stocking quantities, markdown time schedule, and markdown price to maximize mutual profit. Next, we consider a decentralized supply chain. An uncoordinated contract is designed in which decisions are decentralized to optimize the individual party's objective function. Here, three sources of system inefficiencies cause the decentralized system to earn a lower expected system profit than that in the integrated supply chain. The three sources are as follows: in the decentralized system the retailer tends to (1) stock less, and (2) keep a longer sales period, and the DCO tends to (3) stock fewer leftovers inventories and charge a higher markdown price. Finally, a numerical experiment is provided to compare the coordinated model with the uncoordinated model to explore factors that make coordination an effective approach.

• 동의생리병리학회지
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• 제22권2호
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• pp.427-430
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• 2008

Serious controls and cares using ID numbers and barcode needed throughly to have appropriate management in clinical tissues and nucleic acids inventories because these samples are the most essential and important materials in the experimental research laboratories. While almost all of the laboratories using and handling DNA samples as starting materials in their research, problems such as mixing up of two or more different samples together, contamination with other samples, and/or mistakes can occur, especially when it comes with large number of samples. These problems are rather frequent even though researchers pay more attentions to be far away from these obstacles. It has been such a long time since PCR became useful as an important and essential biological research tool among lots of bio-scientific research methods. In this research, we tried to set up a simple and cost-effective genotyping method using PCR and agarose gels, instead of expensive automated machines, for identification and discrimination among those DNA samples, as a kind of low level quality control and sample inventory management.

• Nuclear Engineering and Technology
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• 제45권5호
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• pp.589-596
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• 2013

In a pressurized heavy water reactor, following loss of the primary coolant, severe core damage would begin with the depletion of the liquid moderator, exposing the top row of internally-voided fuel channels to steam cooling conditions on the inside and outside. The uncovered fuel channels would heat up, deform and disassemble into core debris. Large inventories of water passively reduce the rate of progression of the accident, prolonging the time for complete loss of engineered heat sinks. The efficacy of available backup and ultimate heat sinks, available in a CANDU 6 reactor, in mitigating the consequences of a prolonged station blackout scenario was analysed using the MAAP4-CANDU code. The analysis indicated that the steam generator secondary side water inventory is the most effective heat sink during the accident. Additional heat sinks such as the primary coolant, moderator, calandria vault water and end shield water are also able to remove decay heat; however, a gradually increasing mismatch between heat generation and heat removal occurs over the course of the postulated event. This mismatch is equivalent to an additional water inventory estimated to be 350,000 kg at the time of calandria vessel failure. In the Enhanced CANDU 6 reactor ~2,040,000 kg of water in the reserve water tank is available for prolonged emergencies requiring heat sinks.

• Nuclear Engineering and Technology
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• 제48권5호
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• pp.1109-1119
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• 2016

Although, the direct use of spent pressurized water reactor (PWR) fuel in CANda Deuterium Uranium (CANDU) reactors (DUPIC) cycle is still under investigation, DUPIC cycle is a promising method for uranium utilization improvement, for reduction of high level nuclear waste, and for high degree of proliferation resistance. This paper focuses on the effect of DUPIC cycle on CANDU reactor safety parameters. MCNP6 was used for lattice cell simulation of a typical 3,411 MWth PWR fueled by $UO_2$ enriched to 4.5w/o U-235 to calculate the spent fuel inventories after a burnup of 51.7 MWd/kgU. The code was also used to simulate the lattice cell of CANDU-6 reactor fueled with spent fuel after its fabrication into the standard 37-element fuel bundle. It is assumed a 5-year cooling time between the spent fuel discharges from the PWR to the loading into the CANDU-6. The simulation was carried out to calculate the burnup and the effect of DUPIC fuel on: (1) the power distribution amongst the fuel elements of the bundle; (2) the coolant void reactivity; and (3) the reactor point-kinetics parameters.

• 산업경영시스템학회지
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• 제43권1호
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• pp.70-78
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• 2020

Under the situation which customer orders are cancelled unless all products in the order are delivered all at once, this paper concentrates on the purchase dependent demands and explores the systematic approach to implant the purchase dependence into the multi-product inventory model. First, by acknowledging that it is a challenging task to formulate a suitable inventory model for the purchase dependence, we derive the optimal solution condition using an EOQ model and extend the optimal solution condition to periodic review models. Then, through the comparison simulation of four inventory policies regarding several degrees of purchase dependence, we demonstrate that the inventory models which consider the purchase dependence generate less total cost than the inventory models which ignore the purchase dependence. In general, the inventory models which consider the purchase dependence reduce the loss of sales by maintaining more inventories, which results in reducing the total cost. Consequently, the simulation result supports the effectiveness of this paper's approach. In addition, this paper uses the individual order period and joint order period obtained from the EOQ model for the multi-product inventory model. Through the in-depth analysis of comparing the two models, we observe that the model of using the joint order period produces less total cost when the degree of purchase dependence is high, but the model of using the individual order period produces less total cost when the degree of purchase dependence is low.

• 디지털콘텐츠학회 논문지
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• 제19권5호
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• pp.899-906
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• 2018

재난피해 손실의 최소화를 위하여 관련 정보의 체계적인 구축과 피해를 정량적으로 분석하는 것은 재난 예방, 대응 복구 등의 재난관리 전 단계에 있어서 매우 중요하다. 우리나라를 비롯한 세계 각국에서는 해당 지역 또는 특정 환경에 적합한 인벤토리, 취약성 정보, 재해 위험지도 등의 정보 구축 연구뿐만 아니라 경제적 손실, 인명 손실, 건물 손상도 추정, 피난처 분석 등을 포함한 재해 피해 평가 및 분석 도구 개발에 많은 노력을 기울이고 있다. 본 논문은 지진 재해를 중심으로 대표적인 지진 피해 위험 분석 도구를 선정하고, 이를 비교 분석하였다. 이를 통해, 관련분야의 연구자들뿐만 아니라 재난 관리 의사 결정자 등에게 적합한 분석도구의 선정, 응용 소프트웨어의 개발 및 확장 등에 있어서 유용한 정보를 제공할 수 있을 것이다.

• 한국생활과학회지
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• 제21권6호
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• pp.1059-1082
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• 2012

The purpose of this study was to analyze the trends, research methodology and findings of various researches on family resilience published in Korea over the past 13 years. A total of 93 publications related to family resilience between 1999 and June of 2012 were analyzed; 72 journal articles and 21 doctoral dissertations which had not been published in academic journals. The results are as follows; (1) There has been steady increase in the number of related researches since 1999, with a significant increase since the mid-2000s as various nontraditional families emerged and the perception of family problems began to change. (2) With regards to the methodology, the majority of the studies were empirical, using quantitative methods in both data collection and analysis. Most measurement scales employed were based on inventories developed by foreign researchers. (3) The research subjects encompass a wide range of individuals and groups from both vulnerable families and families from the general population. Additionally, some researches focused on special interest areas including program development & evaluation and scale development. Although research on family resilience has increased in quantity, there needs to be more qualitative, longitudinal and theory grounded studies on different families and individual types to better understand family resilience in depth. In addition, specific measurement scales reflecting the unique Korean family culture should be developed. Other challenges and suggestions for future research on family resilience are discussed.

• 경영과학
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• 제31권3호
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• pp.61-76
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• 2014

There are three methods for calculating the optimal level for spare part inventories in a MIME (Multi Indenture and Multi Echelon) system : marginal analysis, Lagrangian relaxation method, and genetic algorithm. However, their solutions are sub-optimal solutions because the MIME system is neither convex nor separable by items. To be more specific, SRUs (Shop Replaceable Units) are required to fix a defected LRU (Line Replaceable Unit) because one LRU consists of several SRUs. Therefore, the level of both SRU and LRU cannot be calculated independently. Based on the limitations of three existing methods, we proposes a improved algorithm applying marginal analysis on determining LRU stock level and genetic algorithm on determining SRU stock level. It can draw optimal combinations on LRUs through separating SRUs. More, genetic algorithm enables to extend the solution search space of a SRU which is restricted in marginal analysis applying greedy algorithm. In the numerical analysis, we compare the performance of three existing methods and the proposed algorithm. The research model guarantees better results than the existing analytical methods. More, the performance variation of the proposed method is relatively low, which means one execution is enough to get the better result.

• 제어로봇시스템학회논문지
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• 제18권9호
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• pp.854-862
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• 2012

The optimal design of batch-storage network by using periodic square wave model provides analytical lot sizing equations for a complex supply chain network characterized as multi-supplier, multi-product, multi-stage, non-serial, multi-customer, cyclic system including recycling and/or remanufacturing. The network structure includes multiple currency flows as well as material flows. The processes are represented by multiple feedstock/product materials with fixed composition which are very suitable for production processes. In this study, transportation processes that carry multiple materials with unknown composition are added and the time frame is changed from single period into multiple periods in order to represent nonperiodic parameter variations. The objective function of the optimization involves minimizing the opportunity costs of annualized capital investments and currency/material inventories minus the benefit to stockholders in the numeraire currency. The expressions for the Kuhn-Tucker conditions of the optimization problem are reduced to a multiperiod subproblem for average flow rates and analytical lot-sizing equations. The multiperiod lot sizing equations are different from single period ones. The effects of corporate income taxes, interest rates and exchange rates are incorporated.

• 대한안전경영과학회지
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• 제4권1호
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• pp.105-114
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• 2002

Nowadays, most companies seek after the greatest profit by means of offering the goods which consumers want timely and efficiently and minimizing the cost of inventory and distribution channel which amounts to the great portion of total cost. And according as EC(Electronic Commerce) market has increased rapidly, SCM(Supply Chain Management) for EC become one of the most important facts for companies, therefore this paper suggest SCM scheme which EC, especially B to C, is added to the existing commerce system. This paper uses internet for information integration of distribution channel which is away from one another and applies TOC(Theory of Constraint)'s DBR(Drum-Buffer-Rope) Scheduling for synchronization through the whole supply chain. It is possible to synchronize the whole supply chain by means of making the speed of manufacturing and distribution to be controlled by consumer's order which is received in distribution center, and inventory and loss of sales opportunities are minimized by constant. Buffer Management. If inventories in distribution center is short, then it needs to search CCR(Capacity Constraint Resource) in supply chain and to control the speed of manufacturing and distribution according to the ability of CCR. This paper applies PT(Partial Transshipment) strategy for Delivery from distribution center to store or cyber consumer. the strategy this paper suggests chooses neighbour area from area which each distribution center takes charge, and then makes product ordered by cyber consumer which lives in the chosen area to be delivered according to inventory of distribution center.