• Journal of the Korean Society for Precision Engineering
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• v.14 no.6
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• pp.99-105
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• 1997

Recently, with a great interest in micromachine, it is more and more important to promote the way of manufacturing micromachine. The silicon process or the LIGA process was the main method to manufacture micromachine in the past. But, these manufacturing method was 2.5-dimensinal, there was the limit in manufacturing perfect 3-dimensional structure micromachine. In this study, we developed the rapid prototyping system for micromachining and tested its property. We also realized .mu. m-order manu- facturing and 3-dimensional structure processing. The results showed the possibility of micromachining with the rapid prototyping system.

• Journal of Power System Engineering
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• v.10 no.2
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• pp.36-40
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• 2006

In order to prevent the environmental pollution, the dryers are commonly used to treat sludge that one of sewages is polluting the quality of water. Generally, the drying method is various as to the property of material and use. Rotary dryer is a good apparatus to treat them. It is the way that is to make substance transmission and heat using hot air between sludge particle and heated gas. In this paper, we developed a 3-pass rotary dryer for a design program for the 3-pass rotary dryer with various conditions. The working conditions of dryer are a raw sludge feed rate, input & output water content and operation time etc.

• Korean Journal of Computational Design and Engineering
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• v.6 no.2
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• pp.140-146
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• 2001

A nuclear Power Plant is composed of a number of mechanical components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to evaluate the integrity of these mechanical components, a lot of data are required including inspection data, geometrical data, material properties, etc. Therefore, an effective database system is essential to manage the integrity of nuclear power plant. For this purpose, an internet based virtual reality environment and web database system was proposed. The developed virtual reality environment provides realistic geometrical configurations of mechanical components using VRML (Virtual Reality Modeling Language). The virtual reality environment was linked with the web database, which can manage the required data for the integrity evaluation. The proposed system is able to share the information regarding the integrity evaluation through internet, and thus, will be suitable for an integrated system for the maintenance of mechanical components.

• Journal of the Korean Solar Energy Society
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• v.24 no.4
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• pp.55-63
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• 2004

The purpose of this study is to development of life cycle cost analysis methodology of HVAC system for decision maker. The results of this study are as follows; maintenance/management, equipment construction, planning/design, and demolition/sell phases (1) To develop the cost breakdown structure for LCC in HVAC system, this study apply the method of additional pertinent level, title, CBS number, block number and variable index. (2) LCC analysis order of HVAC system compose four phase. (3) Life cycle costing influence diagram can bring us to make the most efficient decision through a visual graphical diagram that is shown relationship among variables and that decision maker traces easily from life cycle cost analysis situation.

• Korean System Dynamics Review
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• v.15 no.4
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• pp.61-84
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• 2014

This study aims to explore the development and application of a simulated skills package designed to improve nursing students' knowledge integration and their system thinking(ST) skills about congestive heart failure(CHF) and to identify the change in students' ST levels using a ST-based learning approach. A simulated learning support package was developed by nurse educators and ST experts. The developed program was implemented with 35 third-year nursing students from S university in Seoul. The subjects improved their ST skills regarding CHF after intervention. Mean test scores for students completing the program were significantly higher than pre-intervention scores, including measures of direction of causality, polarity of causal relationship, feedback loop, polarity of feedback loop (reinforcing, balancing) and time delay (t=2.26~6.53, p=.030~p<.001). It is suggested that more educational programs be developed on various topics in order for nursing students to improve their ST skills as well as knowledge integration in clinical nursing practicum packages.

• International Journal of Precision Engineering and Manufacturing
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• v.5 no.2
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• pp.5-15
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• 2004

A telecooperation system supports synchronous cooperation among all the product development partners and enables compensation of deficits concerning traditional information/communication technologies. By analyzing the product development processes and communication scenarios of a company manufacturing automobile parts, the specifications for the suitable telecooperation system were defined. An integrated telecooperation platform that combines the commercial softwares with the new developed modules for customer-oriented functionalities was created as a product development guideline. Future work is strongly required in order to define the best way to improve the integrated platform, based on the functionality of ERP and PDM systems.

• Journal of Agricultural Extension & Community Development
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• v.13 no.2
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• pp.341-355
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• 2006

The purpose of this study is to introduce the case of advancement of rural zoning system in a local government of Japan. The Matzgawa county, one of the local governments in Japan, sets up a new zoning system which advanced in using rural resources. In order to develop and revitalize rural region, it is necessary to use all kinds of rural resources, including agricultural as well as non-agricultural resources comprehensively. Also, the classification of agricultural land use should be reformed. The zoning on rural land should be changed to include not only agricultural use but also non-agricultural use, so as to manage comprehensively agricultural land use and its conversions. Furthermore, the land use regulation should be applied to each zone of the agricultural land.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.36T no.2
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• pp.14-20
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• 1999

In this paper, we discuss about implementation of a wireless communication system for a distributed autonomous robotic system. In order to achieve cooperative behavior among mobile robots, it is required to perform communication. Based on this requirements, we examined to the application in a wireless communication system used by mobile robots. This paper describes a conceptual and experimental framework which provides a distributed control architecture for the study of interactions between multiple mobile robots.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.576-580
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• 2003

In order to assess the spectrum usage efficiency in mobile radio services, we consider the capacity limits of a CDMA system. The maximum achievable capacity per $km^2$ is viewed as a meaningful figure of merit for a cellular system and a method is proposed here to estimate the minimum achievable distance between adjacent base stations in the case of CDMA. The probability for entering in soft handover state is used as a limit for densification in a CDMA system. From this criterion, conditions on the minimum possible cell radius are derived.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.227-232
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• 2007

The autoreclosing is applied to power system for maintaining system stability and continuity of supply. Developments on distributed generation(DG) grows significantly by environmental issues and economical issues. If the DG is connected to distribution system, the DG influences the technical aspects such as power quality, protection and stability. It causes the challenges to protection, especially to reclosing. In order to achieve reliability and safety of the distribution system, the rules and guidelines suggest that the DG units should be rapidly disconnected from the network before the reclosing. If the DG is disconnected whenever the fault occurs, it cannot be utilized effectively. This paper presents the adaptive reclosing algorithm considering the DG. The algorithm consists of angle oscillation's judgment, EEEAC(Emergency Expanded Equal-Area Criterion), calculation of optimal reclosing time and re-connection algorithm. The simulation is implemented for the DG technology by using EMTP MODELS. The simulation results show that the transient stability is maintained and the DG is protected against disturbance.