• IEMEK Journal of Embedded Systems and Applications
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• v.3 no.2
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• pp.82-90
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• 2008

In this paper, we introduce a biped walking robot which can do static walking with 22 degree-of-freedoms. The developed biped walking robot is 480mm tall and 2500g, and is constructed by 22 RC servo motors. Before making an active algorithm, we generate the motions of robot with a motion simulator developed using C language. The two dimensional simulator is based on the inverse kinematics and D-H transform. The simulator implements various motions as we input the ankle's trajectory. Also the simulator is developed by applying the principle of inverted pendulum to acquisite the center of gravity. As we use this simulator, we can get the best appropriate angle of ankle or pelvic when the robot lifts up its one side leg during the walking. We implement the walking motions which is based on the data(angle) getting from both of simulators. The robot can be controlled by text shaped command through RF signal of wireless modem which is connected with laptop computer by serial cable.

• The Journal of the Acoustical Society of Korea
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• v.23 no.1E
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• pp.16-18
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• 2004

There have been numerous studies on the enhancement of the noisy speech signal. In this paper, I propose a completely new speech enhancement method, that is, a filtering of a dissonant frequency combined with noise reduction algorithm. The simulation results indicate that the proposed method provides a significant gain in audible improvement compared with the conventional method. Therefore if the proposed enhancement scheme is used as a pre-filter, the perceptual quality of speech is greatly enhanced.

• Korean Journal of Computational Design and Engineering
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• v.16 no.4
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• pp.292-299
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• 2011

Han-ok has a long history and cultural traditions. It has green and healthy and culture but high construction costs, thermal insulation performance of residential and vulnerable to fires and have a weakness for maintenance. However, modernized resident housing, Han-ok is required to improve in terms of environmental aspect due to its weakness for insulating and inconvenience for modem era. Also Han-Ok's building is criticized as a huge dependence on subjective building experiences. This is pointed to be the biggest problem, Han-ok has. Traditionally it does not have a scientific and specific manual for construction. In this research, process simulation was adopted to develop Han-Ok's environmental improvements. In terms of LCC (Life Cycle Cost) aspect, however, Han-Ok's environmental characteristics are examined to suggest an appropriate Han-Ok construction method. Also the result of this research would be utilized to base the information database for efficient constructing and its management in new Han-Ok constructing industry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.400-400
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• 2009

In a wide variety of high-voltage applications surface flashover plays major role in the system's performance and yet has not been studied in great detail for atmospheric conditions with modem diagnostic tools. surface flashover for both direct current and pulsed voltages in considered. within the setup, parameters such as geometry, material characteristics of the applied voltage can be altered. This paper review surface flashover of insulator, primarily in atmosphere. It discusses theories and models relating to surface flashover and experimental results. surface flashover of insulators in atmosphere generally is initiated by the emission of electrons from the cathode triple junction point (the region where the electrode, insulator, air). the electrode material was copper, and a AC voltage was applied between the electrodes. these results were compared with the surface flashover characteristic of epoxy.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.480-481
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• 2009

In the paper we study for the ubiquitous networking based on power line communication technology with digital signal transmission. The necessity of research for using resources in the network effectively is being increase as network to use the PLC with smart grid networking. The data rate has compared with implemented modem 250Mbps in the pixel resolution and bandwidth, which has degraded with 80%. We also proposed for design of high-definition digital signal transceiver, which has used in the network between digital multimedia with PLC. Using resources in the network effectively can be also verified with this research.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1633-1636
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• 2003

In this paper, we developed the scheme to grow to use newly added disk space without having to kill the application, unmount file system. This scheme, called online resizing, can resize the file system layout with the advent of Logical Volume Manager. The online resizing scheme is designed and implemented in linux cluster system where multiple hosts share the disk data in storage area network environment. It is incorporated with SANfs shared file system and can perform resizing technique with SANfs-VM volume manager. The experimental result shows that it can maximize the availability and capacity of the SANfs system which are important for modem servers where must not lose their customer.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.55 no.3
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• pp.123-127
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• 2006

In a heating control system, the indoor temperature controller transfers temperature signals inputted from the temperature sensor and the user to the valve controller. The valve controller receives these signals then the valve controller controls the valve driving motor on two position control and controls the indoor temperature. When setting up a new valve driving motor from a long distance it is necessary to set up a new valve controller. But occasionary, due to construction, It is impossible to wire between the existing valve controller and the new valve controller. In this situation, the new and existing valve controllers can communicate via power line communication. In this paper it is proposed heating control system controls on two position control via power line communication.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.426-430
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• 1996

A new generator excitation system using a boost-buck chopper as a kind of static exciters is proposed to overcome the lack of field forcing capability of the bus fed exciter under the Input line fault condition. It increases or maintains the generator field current by boosting the field voltage in the case of the input AC line voltage drop during and immediately after a fault. The validity of the proposed excitation system is verified with the computer simulation. The generator stability according to the each difference exciter is tested using a commercial software package-CYME. The simulation results of the stability analysis on the generator with the proposed exciter is better than that of the bus fed exciter. This boost-buck chopper exciter can be simply implemented and controlled by the modem power electronics technology.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.629-631
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• 1996

Recently, to increasing the transportation efficiency is to be a important view points in modem railway systems. Therefore the railway communication has an important meaning for the safety of train traffic. In this paper, we have proposed to use HDLC protocol for ground-to-train data transmission, which has some merits of efficiency in data transmission, reliability and bit transparency. Also we describes the HDLC application for data transmission in railway communication.

• 한국전산유체공학회:학술대회논문집
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• 2000.10a
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• pp.9-14
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• 2000

Computational methods can be classified roughly into two parts: one is the methods based on a potential flow theory, and the other is numerical solvers(CFD) based on Navier-Stockes equation. Methods based on a potential theory are more effective than CFD when the free surface effect is considered. Especially Rankine source method seems to become widespread for simulations of wave making problems. For computations of viscous flow problems, CFD techniques have rapidly been developed and have shown many successful results in the viscous flow calculation. Present paper introduces a computational system 'WAVIS' which includes a pre-processor, potential ant viscous flow solvers and a post-processor. To validate the system, the calculated results for modem commercial hull forms are compared with measurements. It is found that the results from the system are in good agreement with the experimental data, illustrating the accuracy of the numerical methods employed for WAVIS.