• Proceedings of the KSR Conference
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• 2004.10a
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• pp.824-829
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• 2004

In this paper, the process of development of resilient sleepers, which improves the train safety, passenger comfort and reduces the noise and vibration, is presented. To optimize the bonding method between elastic pad and PC sleeper, special pad shape like arrow is adopted and is applied in manufacturing. Bonding strength and reduction effects of vibration of the resilient sleepers are experimentally investigated. From the experiment results, it is investigated that the bonding strenth is enough to satisfaction the criteria and the vibration characteristic is also more effective for sleeper with elastic pad than that in ordinary PC form. These results indicate that the elastic pad can reduce possibility of rail-corrugations and thus resulting in the reduction of maintenance costs.

• Korean Journal of Oriental Medicine
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• v.7 no.1
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• pp.17-37
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• 2001

This report studies the history of diagnostic development of Myeong Dynasty(明代). This period is the success of Keum-Won Dynasty(金元代) when the special development of medicin was taken, and is the origin of the developement of medicine of Cheong Dynasty(淸代). The conclusion is like this. The palpitation was developed to be papular, to illustrate and to be simple. The development of seeing diagnostics of Myeong Dynasty was characterized the entrance of special book of seeing diagnostics, the study of finger print of child and the development of seeing tongue diagnostics. In Myeong Dynasty, discrimination of smell(辨氣) theory was developed with the development of fever school. The development of discrimination of symptoms of Myeong Dynasty was finished in every realms, specially in discrimination of symptoms of fever.

• Advances in materials Research
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• v.1 no.1
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• pp.13-29
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• 2012

In order to simultaneously enhance the strength and plasticity in nanostructured / ultrafine-grained alloys, a strategy of introducing multiple length scales into microstructure (or called bimodal composite microstructure) has been developed recently. This paper presents a brief overview of the alloy developement and the mechanical behavior of ultrafine-grained Ti-Fe-based alloys with different length-scale phases, i.e., micrometer-sized primary phases (dendrites or eutectic) embedded in an ultrafine-grained eutectic matrix. These ultrafine-grained titanium bimodal composites could be directly obtained through a simple single-step solidification process. The as-prepared composites exhibit superior mechanical properties, including high strength of 2000-2700 MPa, large plasticity up to 15-20% and high specific strength. Plastic deformation of the ultrafine-grained titanium bimodal composites occurs through a combination of dislocation-based slip in the nano-/ultrafine scale matrix and constraint multiple shear banding around the micrometer-sized primary phase. The microstructural charactersitcs associated to the mechanical behaivor have been detailed discussed.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1996.03a
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• pp.124-131
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• 1996

The use of small hemispherical high-speed precision bearing has increased drastically these days in the field of computer disk driver, highteech devices as well as communication and electronic device drivers. It was suggested that the new polishing process adopting the diamond grinding wheel and polishing tool instead of multi stage lapping processes, which enables the mass production of the bearing by reduction of polishing time. Polishing mechanism was analysed and the results were applied to the design and manufacturing of the polishing system. Experiments for selection of optimal polishing conditions were carried out using the polishing system.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.10 no.6
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• pp.1-7
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• 2001

It is very important to test circular motion accuracy of NC machine tools as it affects all other machines machined by them in industries. In this paper, it has become possible to detect errors of linear displacement of radial directions for circle tar motion accuracy test using newly assembled magnetic type of linear scale so called Magnescale ball-bar system. It has also organized computer program systems using tick pulses come out from computer for getting error motion data at colt start time interval in circular motion test on NC lathe. Error data gotten from test is expressed to plots and analysed to numerics by various statistical treatments.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.3
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• pp.33-45
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• 1997

In this paper, we propsoe a new method of th ecommunication system for cooperative behaviors and works in collective autonomous mobile robots. A communication function among the collective robots is essential to intelligent cooperative works. In genral, global communication is effective for small number of robots. However when the number of robot goes on increasing, this becomes difficult to be realized because of limited communication capacity and increasing amount of information to handle. And also the problems such as communciation interfeence and improper message transmission occur. So we propose local communication system based on infrared sensor to realize the cooperative behavior among robots as the solution of above problem. It is possible to prevent overflow of information and exchange of complex information by fusion sign board model which transmits the information to unspecified robots and message passing model which communicate a specific robot. And we formularize optimal communication range by analysis of information propagation mechanism from the proposed comunication system. At last we verify the effectiveness of the proposed communication system from example of cooperative works.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.884-888
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• 2010

하천제방은 홍수의 위험 방지에 중요한 역할을 하며 하천의 범람으로부터 제내지의 인명, 가옥, 재산, 각종 시설물 등을 보호하기 위하여 설치되는 시설물로서 침수피해 방지와 같은 중요 기능을 가지고 있다. 이러한 하천제방의 적정규모를 결정하기 위해서는 대상지역의 수리 수문학적 특성, 지형조건에 관한 조사 및 연구 이외에 경제적인 검토가 수반되어야 하며, 제대로 검토되지 않을 경우 제방이 누수 또는 침하, 붕괴되어 범람방지 기능을 상실하는 현상이 일어나게 된다. 국내 하천유역에서도 과거 전국에 걸쳐 제방 붕괴현상이 일어나 많은 범람침수 피해가 발생하였다. 본 연구에서는 제방붕괴의 일반적인 원인으로 지적되고 있는 월류, 제체의 불안정, 과도한 변위, 급격한 수위의 감소 등으로 발생할 수 있는 현상 및 문제점들을 검토하였다. 이로부터 기하학적 인자, 수리학적 인자, 수공구조물 인자, 정성적 인자 등 4가지 분류로 구분하였으며, 총 12가지 세부인자를 제시하였다. 제시된 인자를 토대로 시험 대상유역인 감천과 남강에 적용하여 인자별 영향을 산정하였으며, 이로부터 위험도를 평가하였다.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2603-2605
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• 2001

In this paper, we introduce the concept and construction of a web-based bidirectional remote laboratory system. In this configuration, students build and test circuits using internet at home, and the circuit components and experimental equipments at the school are interconnected following student's design. This means that it is possible to choose components, build circuits, connect experiment equipments, control the equipment. and receive measurement results at home in real-time. Labview and Java are used to control this system efficiently and to provide user-friendly environments. Computer-based function generator, DMM, and oscilloscope are used and switch module is used to change interconnections. It was found that a system adopting computer-based instruments, which include PXI/CompactPCI modules and PC plug-in board, provide better performance than that adopting stand-alone instruments connected with GPIB. It is believed that, if this system is installed, the real experiments, not the virtual experiments based on simulation, can be done at home effectively, resulting in revolutional change in engineering education.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2672-2674
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• 2001

웹가속기(web accelerator)는 웹서버와 동일한 컴퓨터에서 동작하여 웹서버의 서비스 속도를 향상시키는 것을 주된 목적으로 한다. 이는 캐싱서버와는 달리 별도의 머신을 필요로 하지 않고 커널레벨에서 클라이언트의 요청을 가로채어 처리하므로 일반적인 Apache와 같은 사용자 응용 프로그램보다 더 빠르게 서비스를 수행할 수 있다. 정적페이지(static page)와 동적페이지(dynamic page)를 처리할 수 있고, 커널레벨에서 동작하므로 일반적인 웹서버가 지니는 Multi-thread 구조의 속도상 overhead와 메모리 복사와 디스크 접근에서 일어나는 자원 낭비를 줄임으로써, 웹서버의 응답속도(response time) 및 초당처리요청수(request/sec)를 개선시킬 수 있다.

• IE interfaces
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• v.13 no.4
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• pp.725-737
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• 2000

This paper deals with the design and the development of user interface for a high speed linear programming solving system. The general users' educational and practical requirements are analyzed and the functionalities that should be implemented for the requirements are designed. The user interface of the system consists of various carefully designed built-in commands that perform the functionalities. The names of the build-in commands are chosen to enhance the users' convenience. We also address the various factors that should be considered in the design of the linear programming solvers when integrated with the user interface. As one of user-friendly environments, data input system that can understand user-written arithmetic form is added to our user interface system. Finally, we compare our system with other user interface systems.