• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.1
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• pp.47-56
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• 2012

Service Parts Management is defined as a supply management associated with service parts from the part suppliers to the final customer. A series of process to improve the customer service level by forecasting the demand and to minimize cost by maintaining the inventory level is included. Uniqueness such as missing value correction, the data pattern analysis and planned order system is designed and implemented. Main feature of order management system is to calculate order amount and order time based on selection of optimal forecasting algorithm.

• Journal of the Korea Safety Management & Science
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• v.19 no.3
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• pp.97-107
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• 2017

This research studies on the demand forecasting for service parts considering parts life cycle, that gets relatively less attentions in the field of forecasting. Our goal is to develop forecasting method robust across many situations, not necessarily optimal for a limited number of specific situations. For this purpose, we first extensively analyze the drawbacks of the existing forecasting methods, then we propose the new demand forecasting method by using these findings and reinforcement leaning technique. Using simulation experiments, we proved that the proposed forecasting method is better than the existing methods under various experimental environments.

• The Korean Journal of Health Service Management
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• v.7 no.1
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• pp.119-131
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• 2013

The purpose of this study is to analyze contents on media about the problems of long-term care facilities. For achieving this purpose, we reviewed 'KINDS(http://www.kinds.or.kr/)' from July, 2008 to May, 2012 which was an synthetic newspaper and TV news searching system. Among 320 articles, we finally analyzed 72 articles: 218 articles were duplicated and 30 articles did not directly related or were not objective. The results were divided with seven parts: 'long-term care facilities', 'employee' 'health care and accidents', 'providing and management of service', 'meals related problems', 'maltreatment of client', 'disorders & unfairness long-term care benefit. Among these seven parts, we could confirm specific and major problems, which were lack of safety management, incompleteness facilities & equipments, shortage of long-term care manpower, insufficient service providing low quality of service, hiding money from elderly's accounts, and providing some money to get national subsidies. For resolving these problems, the long-term service guidelines must be prepared and the related facilities must cooperate each other for providing high quality of service. In addition, the efficient systems must be made to find out long-term care problems and unfairness of service providing and strict management rules or sanctions must be needed.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.1864-1870
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• 2007

The inspection periods for the metro EMU maintenances vary variously according to the countries and railway operators. And the inspection systems vary according to the safety, economical, technical aspects, and also the social environments like passengers and maintenance qualities, etc. Also, in economic point of view, maintenance requires the man power, facilities, equipments, purchasing of parts and the loss of not being in revenue service during the maintenance period. Recently, there is a tendency that the inspection periods are extended gradually owing to the increased reliabilities of the equipments and parts of EMUs. Even if it is the EMUs that are already be in service, once the inspection method is innovated, the inspection time can be reduced. The inspection management innovation scheme includes such methods as the complete module to module replacement when trouble shooting a faulty parts before putting the EMU back to revenue service, the replacements of parts in complete set unit for the heavy maintenance, the establishments of exchange periods for the wasting parts, modernization of inspection equipments, introduction of RAMS for the reliability improvement and computerization of EMU maintenance management, etc. I think it is possible to optimize the inspection scopes and periods per parts and equipments by the introduction of RAMS.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.73-76
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• 2006

International Roaming is a kind of telecommunication service that enables subscribers use the same mobile number when they go abroad and access other service provider's network. International roaming call is made through three network parts-home (original service provider) network, intermediate network, and local (overseas service provider) network. It is not possible to monitor every section of whole roaming service network because service providers do not provide their network management information to other service providers. The limitation causes harsh problem when a service anomaly arises and operators have to confirm the reason of failure. To solve this problem, we propose a scheme that deduces roaming service status of each overseas service provider using internal network management information. SK telecom implemented a international roaming service management system based on the scheme using performance measurement of signaling points, roaming service nodes, and charging data from existing network management systems.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.2
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• pp.24-35
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• 2021

Due to increasing awareness on the treatment of end-of-use/life products, disassembly has been a fast-growing research area of interest for many researchers over recent decades. This paper introduces a novel lot-sizing problem that has not been studied in the literature, which is the service-parts lot-sizing with disassembly option. The disassembly option implies that the demands of service parts can be fulfilled by newly manufactured parts, but also by disassembled parts. The disassembled parts are the ones recovered after the disassembly of end-of-use/life products. The objective of the considered problem is to maximize the total profit, i.e., the revenue of selling the service parts minus the total cost of the fixed setup, production, disassembly, inventory holding, and disposal over a planning horizon. This paper proves that the single-period version of the considered problem is NP-hard and suggests a heuristic by combining a simulated annealing algorithm and a linear-programming relaxation. Computational experiment results show that the heuristic generates near-optimal solutions within reasonable computation time, which implies that the heuristic is a viable optimization tool for the service parts inventory management. In addition, sensitivity analyses indicate that deciding an appropriate price of disassembled parts and an appropriate collection amount of EOLs are very important for sustainable service parts systems.

• Journal of Korean Society for Quality Management
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• v.33 no.4
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• pp.12-20
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• 2005

Supply chain management is a total systems approach to delivering manufactured products to the end customer. Using information technology to coordinate all elements of the supply chain from parts suppliers to retailers achieves a level of integration that is a competitive advantage not available in traditional logistics systems. On the other hand, service chain management is an analogous systems approach that is especially suitable for delivering mobile services such as parcel delivery, cable installation, and home health care. The key elements that distinguish service supply chain management from supply chain management are bidirectional optimization, management of productive capacity, and management of perishability. The purpose of this study is to maintain the construction of service chain management by proving that service quality in after-sales service can be improved through service chain management. First of all, supply chain management, service quality, and service chain management were introduced in theoretical research. In empirical research, it was selected the domestic enterprise that produce electronic appliances with after-sales service, and some customers using the enterprise's after-sales service in the metropolitan area were selected as a sample by convenience sampling method and examined.

• Journal of Nutrition and Health
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• v.46 no.6
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• pp.573-588
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• 2013

The objective of this study is to investigate various jobs and foodservice environments, as well as work performances of school foodservice dietitians and nutrition teachers in accordance to the years of service in Daejeon and Chungnam provinces. A survey was conducted among school foodservice dietitians and nutrition teachers; a total of 415 from selected elementary, middle and high schools in the areas. In this study, we surveyed the participants and analyzed the current state of general characteristics, status of their job environments and foodservice environments by frequency, and the averages and differences in work performance with regard to 12 work parts and 57 works using one-way ANOVA and Duncan's multiple range test according to the years of service. Six parts among 12 work parts were significantly different in work performance according to the years of service. The 6 work parts were menu (nutrition) management, utensil recovery and management, sanitation management, foodservice administration & evaluation, dietary habit guide, and other works. The 11-15 years group ranked as the top on the total score and means of work performance. While the 16-years or more group, 6-10 years group, and under 5 years group followed consecutively. Correlation analysis between job or foodservice environments and work performances showed that work performances of school dietitians were mostly influenced by employment status, education level, and annual salary among the variables of job or foodservice environments. Other works, dietary habit guides and menu management were mostly influenced by variables of job and foodservice environments.

• Korean Management Science Review
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• v.28 no.3
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• pp.1-13
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• 2011

Hub-and-spoke transportation network is a powerful and useful network structure that takes full advantage of economies of scale on routes between hubs. In recent studies, the network structure is extended to hybrid hub-andspoke that allows direct transportation between spokes. In this study, we considered more extended network structure which is called hybrid multiple hub-and-spoke that has multiple hubs and allows direct transportation between spokes. We developed a mathematical optimization model for automotive service parts transportation planning under hybrid multiple hub-and-spoke network structure. The model suggests a long-term transportation route planning and a short-term vehicle assignment planning. The model is verified by simulation and validated in real world application to Hyundai Mobis automotive service parts transportation planning. From the simulation result, the model reduced the transportation cost about 24.7%, the total distance about 6.8% and the CO2 emissions about 8.8%. In real world application for 6 months from July to December 2010, the model reduced the transportation cost about 9.1% by changing the long-term transportation route without daily vehicle assignment planning.

• Journal of the Korea Society of Computer and Information
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• v.21 no.3
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• pp.39-45
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• 2016

In this paper, we propose a log management service model for efficient developments of android applications. The proposed model consists of two major parts which are the log collector and the log manager service. The log collector can capture the log information of a target application without modifications, because the collector is composed by aspect-oriented programming. The collected logs are transformed to chunk of data, and the chunk of data is sent to the log management service. The log management service is an android service component and an independent application in another process. So, the log management service can reduce the workload of logging in the target application. Through a case study, we show that the proposed log management service model can reduce the log processing time compared to other models without modifications of a target application.