• Journal of the Korea Furniture Society
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• v.12 no.1
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• pp.125-130
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• 2001

The sofa industry, which is now one of the major furniture industries in Korea, has developed since 1970s as the apartment building boom and the rise of living standards triggered its demand. Among others, durable and high-quality leather sofa had been most favored and excelled other sofas since mid-1980s along with the growth of national economy before IMF control tightened money market in late 1990s. Leather sofa is still favored and its industry has great possibilities to increase as people tend to seek higher and more personalized living conditions with the stabilization of economy. However, there are several problems in the sofa industry due to the current economic difficult conditions, i.e.; 1. It is hard to cut down the cost of raw material as the supply mostly depend on import. 2. It is hard to keep product quality due to technical difficulties. 3. There are still illegal duplicates of foreign or domestic competitors'design. The aim of this study is to examine the reality of the leather sofa industry in Korea and to suggest new vision for its progress.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.13 no.21
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• pp.133-141
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• 1990

Human blood is a perishable product : it has a legal lifetime of 21 days from collection, during which it can be used for transfusion to a Patient of the same type, and after which it has to be discarded. Therefore, blood must be supplied safely and effectively because it is one of the medical resources which keep humanlife. In this study, the effects of blood issuing policies on average inventory levels and average age of blood at transfusion are determined by simulation applied the theory of absorbing Markov chains. And as a practical study, the daily demand distribution of blood is estimated by using the data of B General Hospital. The distribution estimated follows poisson distribution and the estimator of parameter estimated from the poisson distribution is 0.762. Simulation is done by using the parameter. The most important problem when control blood is the amount of outdata. So we compared random policy with Modified LIFO and Modified FIFO by using outdata. As a results it is shown that Modified LIFO and Modified FIFO by using outdata. As a results it Is shown that Modified LIFO and Modified FIFO present better issuing policy than Random Policy.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.43-48
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• 2020

The demand for stable plasma has been on the rise because of the increased delivery power amount in the chamber for improving productivity, and fast and accurate plasma impedance matching become a crucial performance measure for radio frequency (RF) power system in semiconductor manufacturing equipment. In this paper, the overall impedance matching was understood, and voltage and current values were extracted with voltage - current (VI) probe to measure plasma impedance in real-time. Actual matching data were analyzed to derive calibration coefficient for V and I measurements to understand the characteristics of VI probe, and we demonstrated the tendency of RF impedance matching according to changes in load impedance. This preliminary empirical research can contribute to fast RF matching as well as advanced equipment control for the next level of detailed investigation on embedded system based-RF matching controller.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.47
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• pp.289-302
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• 1998

Concurrent Engineering(CE) can provide a competitive edge for companies that have confronted with rapidly changing market requirements, such as shortening of product life cycles, high quality, low cost, diversity of customer demand, and so on. We construct a prototype of integrated information system to support a new product development process by CE concept. This integrated information system can be useful for considering concurrently all of the aspect in the product design process. In this system, an Engineering Database is constructed for gathering data of four departments; i.e. marketing, production, quality control and design department. Also DFM(Design For Manufacturability) is applied for analysis of product design.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.47-55
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• 2006

This study is to provide information in the development of energy conservation technologies by means of technological demand survey covering energy market and industrial field among energy-related technologies. For this purpose, we check both the present state of energy technologies and trends of social change in Korea, and then combine social needs with major, bottleneck, and essential technologies required for the future. The range of this study covers the field of industry, kiln, furnace, metal, building, transport, and electricity. For case study, valid 120 companies among the 500 companies selected randomly in the energy data-base of Korea institute of energy research (KIER) are considered.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.959-965
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• 2009

To meet the demand increasing passengers in railway vehicles, railway transportation service companies are increasing the numbers of cars per train-set. Two solutions, Variable train-set formations and Multiple train-set operation, are common way to increase the transportation capability. These kind of long distance train-set can effect train-set command and control system, and sometimes the digital signals using train line from master cabin can not reach to the systems located the other extremity slave car. This is so called Voltage Drop. This phenomenon is originated from the electrical power consumption and electrical cable resistance, and cause to the equipments or cars located end of the electrical cable way, malfunction or abnormal operations. This voltage drop happens not only in train lines but also Battery Power Lines. The purpose of this investigation is to design high reliability railway vehicles by clarifying the possibility of happening these events case by case, by analyzing the reasons, and finally by finding the best solutions.

• 한국태양에너지학회:학술대회논문집
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• 2011.11a
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• pp.333-337
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• 2011

Central control air-conditioning systems are being replaced with individually controlled air-conditioning system in the university. The amount of growth of electricity consumption is due to the increasing demand of electric heat pump. In winter and summer, the energy consumption showed a tendency to increase. On the other hand, showed less energy in spring and autumn. Increase the amount of electricity than the degree of decline in gas consumption was higher. Can be considered as transitional phenomena. Because electric heat pump, gas driven heat pump and the absorption chiller-heater are used at the same time in some of the buildings.

• Asia pacific journal of information systems
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• v.8 no.3
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• pp.51-73
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• 1998

This paper is to evaluate the application potentials of data mining in the areas of Supply Chain Management (SCM) and to suggest the architectures of Decision Support Systems (DSS) that support data mining activities. We first briefly introduce data mining and review the recent literatures on SCM and then evaluate data mining applications to SCM in three aspects: marketing, operations management and information systems. By analyzing the cases about pricing models in distribution channels, demand forecasting and quality control, it is shown that artificial intelligence techniques such as artificial neural networks, case-based reasoning and expert systems, combined with traditional analysis models, effectively mine the useful knowledge from the large volume of SCM data. Agent-based information system is addressed as an important architecture that enables the pursuit of global optimization of SCM through communication and information sharing among supply chain constituents without loss of their characteristics and independence. We expect that the suggested architectures of intelligent DSS provide the basis in developing information systems for SCM to improve the quality of organizational decisions.

• Journal of Korea Society of Digital Industry and Information Management
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• v.10 no.1
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• pp.17-27
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• 2014

The number of manufacturing companies that demand the ability to assess sustainability in their manufacturing system is rapidly increasing. However, there are still difficulties in assessing their sustainability in manufacturing for decision-making since it is not easy to determine a single index of sustainability in an operational way. To address these difficulties, this paper proposes an operational guidance and system to assess sustainability of production plan as a single index. The IDEF0 model was defined to explain processes and their input, output, control, and mechanism for sustainability assessment. A prototype system was developed based on the concepts presented in the IDEF0 model, and applied to a case study. To conclude, the prototype system proposed in this paper can help manufacturing companies assess sustainability of their production plans and make a decision using a single value resulted from that assessment.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.637-642
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• 2000

In order to control the water quality of freshwater lake in tidal reclaimed land, it is needed to evaluate accurate amount of pollutant loadings from reclaimed paddy field. This study was carried out to investigate the pollutant loading from a reclaimed paddy field. Site of the study was a paddy field located in Taeho reclaimed land, with an areas of 38.5 hectares. The runoff loadings of Total-Nitrogen, Total-Phosphorus, and Chemical Oxygen Demand were 49.5 kg/㏊/yr, 3.2 kg/㏊/yr and 154.0 kg/㏊/yr, respectively. The runoff loadings in Total-Nitrogen and Total-Phosphorus from this study were much higher values than the pollutant load factor of Total-Nitrogen and Total-Phosphorus from the paddy field published by the Ministry of Environment.