• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.236-243
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• 1999

A comparative study on aseismatic performances of various base isolation systems for the multi-span continuous bridge is carried out. Several leading base isolation systems the LRB system the RF system the R-FBI system and the EDF system are considered, The displacement of the deck the deformation of the upper ends of the piers the shear force and the bending moment of the lower ends of the piers are obtained by using the accelerograms of the N00W component of El Centro earthquake(1940) and the N90W component of Mexico City earthquake(1985) Nonlinear time-history analysis is carried out. comparisons of the results with the conventional bearing show that the base isolation systems are very effective in reducing the forces transmitted to the superstructures. Furthermore the results also show that the friction-type base isolation systems are less sensitive to unexpected variations in frequency content of the ground acceleration. The R-FBI system shows a good aseismatic performance comparing with other base isolation systems.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2270-2273
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• 2003

Fuzzy logic control has been widely implemented in air conditioning and ventilation systems which has uncertainty or high robust system. Since the dynamic behaviors of the systems contain complexity and uncertainty in its parameters , several fuzzy logic controllers had been implemented to control room temperature in the field of air conditioning system. In this paper, the fuzzy logic control has been developed to control room temperature and humidity in the precision air conditioning systems. The nonlinear mathematical model was formulated using energy and continuity equations. MATLAB was used to simulate the fuzzy logic control of the multi-variable air conditioning systems. The simulation results show that fuzzy logic controller can reduce the steady-state errors of the room temperature and relative humidity in multivariable air conditioning systems. The offset are less than 0.5 degree Celsius and 3 percent in relative humidity respectively under random step disturbance in heating load and moisture load respectively

• The Journal of Information Systems
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• v.1
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• pp.95-109
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• 1992

A number of success story about various application areas including manufacturing, accounting, finance, education, and engineering are reported. MIS professionals predicted that expert systems would improve the productivity enormously. However, the expert system revolution has not happened yet. Although not reported in the open society widely, there are failure stories of expert systems. Most of problems concerning expert system failure stem from the non-technical issues such as cognitive and psychological problems rather than the technical issues. We hypothesize that human factor principle enables designers to handle most of these non-technical problems elegantly and to improve the performance and acceptance of the expert systems. Major reasons for expert system failure and needs of human factors are discussed. Human factor guidelines to expert system make the prospects of the expert systems with human factors clear and understandable.

• Journal of the Ergonomics Society of Korea
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• v.15 no.1
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• pp.105-117
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• 1996

This study was initiated to investigate (1) whether consumers preferred a specific garment size labeling system and (2) whether consumer's demographic characteristics, clothing behavior, and body size affect their preference of size labeling systems. The survey of consumer's preferences for five size labeling systems included 443 women with 20 to 64 years of age. The result of the survey showed that the subjects' preferences of five size labeling sysems were different significantly. Subjects strongly preferred the old system rather than the revised systems. The subjects least preferred the system with pictogram(system D) and the system with description of the measuring methods of te control dimensions (system E). The subjects/ preference for various garment size labeling systems was different depending on their resident area, educational level, and body size. The garment size labeling system with more information on body measurements (system C) was preferred by the subjects living in the metro city area or subjects having difficulties on purchasing ready-to-wear garments giving reasonable fit. The simplest size labeling system (system A) was strongly preferred by the subjects of low educational level, or the subjects living in the small city.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.58
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• pp.89-100
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• 2000

There use many production management systems for increasing productivity, minimizing inventory, keeping due dates and maximizing use of resources. MRP, GT and JIT are popular among these systems. There use many production management systems for increasing productivity, minimizing inventory, keeping due dates and maximizing use of resources. MRP, GT and JIT are popular among these systems. In this study, we had designed mixed production system which integrated searching and grouping function of GT, purchasing function of JIT and based on MRP and developed related algorithms and applied systems. The developed system was based on appling renewed algorithms for existing MRP system. To test efficiency operated real-data but we have tested renewed algorithms using sample-data because of massive real-data.

• Journal of Drive and Control
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• v.16 no.2
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• pp.59-65
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• 2019

Hydraulic systems have severe nonlinearity inherently compared to other systems like electric control systems. Hence, precise modeling and analysis of the hydraulic control systems are not easy. In this study, the control performance of a hydraulic control system with a feedback linearization compensator and a disturbance observer was analyzed through experiments and numerical simulations. This study mainly focuses on the quantitative investigation of sensitivity on system uncertainties in the hydraulic control system. First, the sensitivity on the system uncertainty of the hydraulic control system with a Feedback Linearization - State Feedback Controller (FL-SFC) was quantitatively analyzed. In addition, the efficacy of a disturbance observer coupled with the FL-SFC for the hydraulic control system was verified in terms of overcoming the control performances deterioration owing to system uncertainty.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.136-148
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• 2015

We analyzed the effect of three different types of inventory systems for saving the total cost using simulation on the system where multiple depots and many retailers disperse on the limited area. Three types of inventory systems are single echelon system with inventory exchange and two-echelon system and the variant two-echelon system. Variant two echelon system is the two-echelon system where the inventory transshipmentsare allowed on every two stage inventory echelons. Inventories kept on every retailer are commonly used for all retailers when certain retailer has stock-out. And when all retailers are stock-out, inventories kept on every depot are commonly used for the retailers whose assigned depots are stock-out. These all three systems are simulated with the constraint of service level on wide range of parameter settings. Simulation results show that cost saving effect appear clear for single echelon system and two-echelon system when shortage cost portion and transportation cost portion becomes large respectively irrespective of depot number. Variant two echelon system seems to be superior to two other systems when transportationcost portion becomes very small. But this superiority is not proved in terms of statistics. So we may conclude that the variant two echelon system may be useless with the higher administrative efforts due to frequent inventory exchange. Also we note that the traditional two echelon system becomes inferior to two other systems in terms of statistics when service level becomes high or when demand variance becomes very large. And inventory integration effect that cost becomes saved when depot number decrease, diminishes when transportation cost or stock-out cost increases irrespective of inventory systems.

• Journal of the Korean Society of Systems Engineering
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• v.16 no.2
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• pp.118-130
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• 2020

Modern weapon systems are composed of complex systems(System of Systems) and require a complex and advanced operational concept that performs missions through interoperability with various weapon systems. In order to derive the operational concept of the weapon system that the military wants to acquire (i.e., single mission, component operation, Joint and Alliance operations), it is necessary to identify the system related to the weapon system, environmental factors and restrictions of the weapon system to be developed. Through the derivation of the operational concept, the weapon system acquisition agency can reasonably and accurately extract various and complex requirements. In this paper, we propose a complementary method of using MND-AF to OCD and ORD required in weapon system acquisition process. MND-AF can increase the understanding and consensus of business stakeholders (users, acquirers, developers, etc.) by showing the results of weapon system analysis from various perspectives. We compare the items in the standard form of OCD and ORD with the MND-AF outputs.

• Journal of Korean Society for Quality Management
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• v.16 no.2
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• pp.48-55
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• 1988

There have been several papers to illustrate how an information system is used in an automated warehouse system. These papers, however. do not carefully address the role of warehouse planning/control systems nor do they recognize how to integrate the management planning/control systems, and automated warehouse system. This article addresses such issues and shows how a business computer system can be used to integrate and unify the warehouse planning/control systems and the automated warehouse system into it single and highly productive operating system.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.735-737
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• 2017

An Off grid or remote solar electric systems are an energy supply to our home or to our companies without the utility of Grid at all. Off grid solar systems are very important for those who live in remote locations especially for developing countries where getting the electric grid is extremely expensive, inconvenient or for those who doesn't need to pay a monthly bill with the electric bill in general. The main critical components of any solar power system or renewable energy harvesting systems are the energy storage systems and its charge controller system. Energy storage systems are the essential integral part of a solar energy harvesting system and in general for all renewable energy harvesting systems. To provide an optimal solution of both high power density and high energy density at the same time we have to use hybrid energy storage systems (HESS), that combine two or more energy storage technologies with complementary characteristics. In this present work, design and simulation we use two storage systems supercapacitor for high power density and lithium based battery for high energy density. Here the system incorporates fast-response supercapacitors to provide power to manage solar smoothing and uses a battery for load shifting. On this paper discuss that the total energy throughout of the battery is much reduced and the typical thermal stresses caused by high discharge rate responses are mitigated by integrating supercapacitors with the battery storage system. In addition of the above discussion the off grid solar electric energy harvesting presented in this research paper includes battery and supercapacitor management system, MPPT (maximum power point tracking) system and back/boost convertors. On this present work the entire model of off grid electric energy harvesting system and all other functional blocks of that system is implemented in MATLAB Simulink.