• Journal of the Korea Society for Simulation
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• v.12 no.3
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• pp.31-40
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• 2003

This paper studies an optimal policy for a certain class of (s, S) inventory control systems, where the demands are characterized by the renewal arrival process. To minimize the average cost over a simulation period, we apply a stochastic optimization algorithm which uses the gradients of parameters, s and S. We obtain the gradients of objective function with respect to ordering amount S and reorder point s via a combined perturbation method. This method uses the infinitesimal perturbation analysis and the smoothed perturbation analysis alternatively according to occurrences of ordering event changes. The optimal estimates of s and S from our simulation results are quite accurate. We consider that this may be due to the estimated gradients of little noise from the regenerative system simulation, and their effect on search procedure when we apply the stochastic optimization algorithm. The directions for future study stemming from this research pertain to extension to the more general inventory system with regard to demand distribution, backlogging policy, lead time, and inter-arrival times of demands. Another direction involves the efficiency of stochastic optimization algorithm related to searching procedure for an improving point of (s, S).

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2007.05a
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• pp.198-208
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• 2007

Recently business enterprises have forced to face in fierce competition in today's global markets due to the short life cycles of products and the higher expectation of customers. Together with continuing advances in communications and transportation technologies, these environments have motivated the continuous evolution of the supply chain and the management techniques. This paper consider three-echelon inventory system which consist of one manufacturer, one distributor and N retailers for a single product under assumption of constant demand. This paper propose the inventory replenishment period using heuristic method and order policy through coordination of inventory replenishment period. The simulation results show that decrease the total cost of the three-echelon inventory system.

• Journal of the Korea Society for Simulation
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• v.12 no.2
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• pp.1-11
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• 2003

In this paper, we focus an optimal policy focus optimal class of (s, S) inventory control systems. To this end, we use the perturbation analysis and apply a stochastic optimization algorithm to minimize the average cost over a period. We obtain the gradients of objective function with respect to ordering amount S and reorder point s via a combined perturbation method. This method uses the infinitesimal perturbation analysis and the smoothed perturbation analysis alternatively according to occurrences of ordering event changes. Our simulation results indicate that the optimal estimates of s and S obtained from a stochastic optimization algorithm are quite accurate. We consider that this may be due to the estimated gradients of little noise from the regenerative system simulation, and their effect on search procedure when we apply the stochastic optimization algorithm. The directions for future study stemming from this research pertain to extension to the more general inventory system with regard to demand distribution, backlogging policy, lead time, and review period. Another directions involves the efficiency of stochastic optimization algorithm related to searching procedure for an improving point of (s, S).

• 한국IT서비스학회:학술대회논문집
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• 2006.05a
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• pp.223-229
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• 2006

최근 각광받고 있는 RFID(Radio Frequency Identification) 기술은 물류, 유통 및 자산관리 분야를 중심으로 그 적용 사례들이 늘고 있다. 본 사례는 정보통신부의 IT839정책의 일환으로 RFID분야의 기술 및 산업 확산을 위해 한국전산원이 주관하여 추진한 2005년도 선도사업 중 하나인 공군 신무기(F-15K) 자산관리시스템 구축사업에 대한 것이다. 이 시스템의 구축을 통해 공군은 군수물자의 정확한 도입현황 파악이 가능하게 되었고, 보유 자산의 현황 및 저장위치 파악이 실시간 가능해졌으며, 수령, 저장, 발송, 재고관리 등 기존의 업무 처리 방식을 간소화하여 업무 소요시간 및 인력을 절감할 수 있었다.

• The KIPS Transactions:PartB
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• v.13B no.5 s.108
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• pp.507-514
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• 2006

Various application systems are developed using RFID as a part of ubiquitous computing, and it is expected that RFID chip will become wide-spread for the distribution industry especially. Efficient and efact intelligent-type of warehouse management system is essential for small-to-medium-sized enterprises in the situation having a trouble in the viewpoint of expense and manpower. In this paper, we implement small-scale warehouse management system using log-based context awareness technology. This system is implemented to be controlled on web, configuring clients to control RFID readers and building up DBMS system in a server. Especially, it grasps user's intention of storing or delivering based on toE data for the history of user's access to the system and it reports user's irregular pattern of warehouse use and serves predictive information of the control of goods in stock. As a result, the proposed system can contribute to enhance efficiency and correctness of small-scale warehouse management.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.2
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• pp.423-437
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• 2015

The IPv6 which solved the exhaustion problem of IPv4's IP address is going to be used for many kinds of industries. As a result, there are some products which can be connected to other connectable things, it called Internet of Things (IoT). With growing new propagated products including networking, each product can get an IP address of IPv6, which means it is possible that things also have their own IP addresses. Thus, IP address management system is more important and needs tracking and collecting system for unused products with IP addresses. This study suggests new distribution tracking and inventory management system for IoT products, which offers a current location of things and manages stocks in the warehouse with the static IP address and the location-based service.

• The Journal of the Korea Contents Association
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• v.9 no.6
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• pp.37-44
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• 2009

In this paper, we present a switched beamforming RFID reader and propose a convenient shopping system using it. The smart gate with the switched beamforming RFID reader(s) improves tag detection probability, tag false alarm probability, automatic detection functionality of shopping system compared to existing RFID based systems. The proposed system consists of a smart gate to read and verify the tags within cart, a check-out counter to approve customer purchase, and a central server to manage inventory & delivery and to analyze customer purchase trend. The proposed shopping system is more practical, convenient, and cost-effective to A/S than existing RFID shopping systems.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.29-36
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• 2007

The using frequency of processed foods and dietician's perception against management of food service at 98 food service institutions located in Jeollabuk-Do were surveyed. Food service institutions included 13 hospitals,38 schools,40 enterprises, and 7 others. Single menu (75.5%) with two (33.7%) or three (57.1%) side dish was offered. In addition, the offering ratio of boiled water and spring water was 37.8 and 32.7%, respectively. The processed foods with high using frequency were kochujang (1.19), sesame oil (1.22), and doenjang (1.30), but that of leek, onion, Chinese cabbage, and radish were 4.95, 4.62, 4.60, and 4.26, respectively. Dietician's major affairs in all type of food service institutions were cooking (64.3%), purchase (48.0%), and personnel managements (39.8%). Dieticians, however, had a low perception against safety and nutrition management. Therefore, in order to prevent the outbreak of food-borne diseases, we estimated that the education and the conversion of dietician' perception against safety and nutrition management were needed.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.327-329
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• 2020

실험실정보관리시스템 (LIMS)은 실험실 데이터를 저장, 가공, 검색 그리고 분석하기 위한 중앙화된 데이터베이스로서 정유, 석유화학, 정밀화학, 제조업, 금속, 제철, 식품, 의약, 연구소, 보건환경, 검사소 등 다양한 분야에 말라하여 적용이 가능한 시스템이다. LIMS를 재고 관리, 임상 연구, 프로젝트 관리 및 환자 데이터 관리를 위한 강력한 IT도구하고 하면서 특히 의료 분야에서 환자 치료가 향상되고 서비스 효율성이 높아짐 것이라고 하고 운영 비용의 절감이 가능하다. 확장성 및 비용절감과 핵심 기능을 위주로 제공하는 클라우드 및 웹 기반 솔루션의 발전으로 제4차 산업혁명의 핵심기술의 산증인의 분야로 기대가 된다.

• Journal of the Korean Operations Research and Management Science Society
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• v.26 no.3
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• pp.105-117
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• 2001

This paper models supply uncertainty in the dynamic Newsboy problem context. The system consists of one supplier and one retailer who places an order to the supplier every period to meet stochastic demand. Supply uncertainty is modeled as the uncertainty in quantities delivered by the supplier. That is, the supplier delivers exactly the amount ordered by the retailer with probability of $\beta$ and the amount minus K with probability of (1-$\beta$). We formulate the problem as a dynamic programming problem and prove that retailer’s optimal replenishment policy is a stationary base-stock policy. Through a numerical study, we found that the cost increase due to supply uncertainty is significant and that the costs increase more rapidly as supply uncertainty increases. We also identified the effects of various system parameters. One of the interesting results is that as retailer’s demand uncertainty, the other uncertainty in our model, increases, the cost increase due to supply uncertainty becomes less significant.