• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1113-1118
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• 2008

In the hot forging process, The forging defects that are caused by metal were strain, temperate, and inclusion. In this paper, the computer simulation analyzed the effective plastic strain and temperature behaviors. The quantitative analyses which proposed the effective mold design of S/CAM shaft was executed. The parameters of forging shape that affected on the optimize conditions that was calculated with simple equation were investigated. it is expected that the developed analysis model and design technique would greatly contribute to the drum brake optimal design considering temperature affected and material behaviors. This development could save more than 20% of production cost and reduced failure rate to more than 30%. By improving the life span of mold from 15,000 to 25,000, financial difficulty of company imposed on a mold manufacture could be overcome.

• Journal of information and communication convergence engineering
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• v.4 no.2
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• pp.67-70
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• 2006

A distributed healthcare monitoring system prototype for clinical and trauma patients was developed, using wireless sensor network node. The proposed system aimed to measure various vital physiological health parameters like ECG and body temperature of patients and elderly persons, and transfer his/her health status wirelessly in Ad-hoc network to remote base station which was connected to doctor's PDA/PC or to a hospital's main Server using wireless sensor node. The system also aims to save the cost of healthcare facility for patients and the operating power of the system because sensor network is deployed widely and the distance from sensor to base station was shorter than in general centralized system. The wireless data communication will follow IEEE 802.15.4 frequency communication with ad-hoc routing thus enabling every motes attached to patients, to form a wireless data network to send data to base-station, providing mobility and convenience to the users in home environment.

• Proceedings of the KIPE Conference
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• 2003.07b
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• pp.998-1001
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• 2003

Recent trend of sensor-less control of induction motor applied for commuter trains in Japan is introduced. Although many inverter-fed induction motor driven trains have been produced so far, most of them were slip frequency based conventional V/f control system using shaft encoder. There arises a new trend to apply speed sensor-less vector control., for this inverter-fed induction motor drive system. The purpose of sensor-less control is to save, cost and improve system reliability. Several sensor-less systems now under testing on the actual railway company. This paper describes the survey of the fundamental structure and feature of representative sensor-less systems mentioned above.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.59-60
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• 2012

A large-scale construction project relies much on the efficiency of construction equipment. Therefore, efficient and accurate measurement on the productivity of construction equipment is one of important task in the construction industry. Based on the motivation, this paper proposes a 11-axis composite sensor for an automatic measurement of construction equipment. A 11-axis composite sensor is composed of a gyroscope, geomagnetic and accelerometer sensor for the purpose of real-time motion captures of construction equipment. It is expected that the proposed system can save considerable time, effort and cost of measuring a efficiency of construction equipment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.250-253
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• 2007

This paper presents a new sustain driver employing energy recovery function to minimize power losses transpired during the operation of plasma display panel. The proposed circuit uses the resonance between the equivalent capacitance of panel and an external inductor to provide/recover energy to/from the panel. The proposed circuit can save the system cost compared with the conventional one, and has high-performance in energy recovery. To verify the validity of the proposed circuit, we implemented experiments based on 7.5 inch AC-PDP.

• Design & Manufacturing
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• v.2 no.1
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• pp.11-14
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• 2008

we can save a development cost and time as computer was used in tool and die design of car fields in die manufacture process. Dimension accuracy errors such as springback, springgo, overcrown and twist were reduced product accuracy and caused trouble to assembly each parts of car. In this paper, CADCEUS was used to modify and optimize results of deflection for a tail gate panel of car parts in order to reduce dimension accuracy errors by springback in sheet metal forming. As CADCEUS was used to apply for a tail gate panel, the time for quality to improve was reduced to 30%.

• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.147-156
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• 1998

It is desirable to use the renewable energy for the greenhouse heating in winter season, it make possible not only to save fossil fuel and conserve green environment but also to promote the quality of agricultural products and reduce the agricultural production cost. In this study the heat pump - PCM latent heat storage system has been developed to use the natural energy as much as possible for the thermal environment control of greenhouse. The coefficient of performance (COP) of the heat pump system was 3~4 with the ambient temperature ranging from 8$^{\circ}C$ to -8$^{\circ}C$, and greenhouse heating effect of the heat pump-PCM latent heat storage system on the basis of the ambient temperature was about 12-15$^{\circ}C$.

• Journal of Environmental Impact Assessment
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• v.18 no.6
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• pp.411-417
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• 2009

Lately the master plan for the Four Major Rivers Restoration Project has been released by the Ministry of Land and Maritime Affairs and relevant ministries. According to the master plan compared with the interim report made on 15 December 2008, the number of weirs for irrigation has increased from 5 to 16, the amount of dredging has increased from 220 million cubic metres to 570 million cubic metres, and the total cost estimated has increased from 14 trillion won to 22 trillion won. A critical review of the master plan by some research group will be summarized focused upon budget, objectives, securing water resource, dredging, and flood control etc. After various experts' forums and field surveys, it is concluded that the government should implement a joint-research program on assessing the impact of the project together with experts and citizens' groups as co-partners, in order to truly save or restore the four major rivers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.213-214
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• 2006

The CAM software for drill grinding has been developed to save time, reduce cost for tool manufacturing and obtain accuracy of tool. In this paper, the developing software for drill will be presented including calculation and simulation of machining processes using 5-axes CNC grinding machine. The algorithm fer helical flute grinding was applied into calculating NC data. The software will generate NC code for machining by using input data of tool geometry, wheel geometry, wheel setting, machine setting. These NC code files will be used in simulator as input file. The simulator provides some functions for simulating machining processes, inspecting and measuring tool geometry.

• Asia pacific journal of information systems
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• v.13 no.1
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• pp.47-72
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• 2003

It is important to retrieve information that a user requires on the web. The web is an open system. The amount of information is increasing rapidly. While each of information was compiled into the database piece at a single platform in the past, it is now compiled into complicated structure at a multi-platform. Restructuring the multi-platform database is needed to efficiently retrieve information. MIRAS(Meta Information Retrieval Agent System) has a multi-platform database on web. This study applies the classification of the existent site's categories to restructure the database systematically. The empirical analysis shows that the suggested method is effective for information retrieval and multi-platform database restructuring. This study helps users to save on time-cost of searching information.