• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 추계학술대회논문집
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• pp.258-261
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• 2006

This study introduces the control of duration time of impulse noises emitted from a high voltage COS fuse of a transformer. When a high voltage COS fuse becomes a short circuit by the over current, the peak sound pressure level over 150 dB(A) is generated at the distance of 2m from a COS Fuse. For the purpose of the reduction of impulse noise, in this study, the reactive type silencer has been utilized. And also electrical interrupting test was experimented. From the experimental results, the reactive type silencer has been shown to have the noise reduction of about 13 dB(A). It has been found that the electrical interception performance of the COS fuse was related to the control of the duration time of impulse noise.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 춘계학술대회 논문집
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• pp.163-167
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• 2009

In this study, the acoustic properties of ceramic sound absorbing materials with different thickness and bulk density were investigated in terms of characteristic impedance, propagation constant, and absorption coefficient. The well-known two-cavity method was used for evaluating those acoustic parameter values. Also, in order to validate the experimentally measured values, the results were compared with the results obtained from Chung and Blaser's transfer function method and SWR method. The experimentally measured values of normal absorption coefficients were generally agreed well with the corresponding values from the transfer function method and the SWR method. Based on the experimental results, the following conclusions could be made. The magnitude of the absorption coefficient and the frequency range of the maximum absorption coefficient were controllable by changing the thickness and bulk density of the sound absorbing materials.

• 한국소음진동공학회논문집
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• 제18권7호
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• pp.783-789
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• 2008

This experimental study describes the noise reduction and the feasibility of short current of a silencer for a high voltage COS(cut out switch) fuse of a transformer. When a high voltage COS fuse becomes a short circuit by the over current, the strong impulse noise over 150 dB(A) is generated. For the purpose of the reduction of impulse noise, in this study, the diffuser type and the reactive type silencers have been designed and tested, respectively. And also the electrical test on the short current is performed. From the experimental results, the well designed reactive type silencer has been shown to have the noise reduction of about 20 dB(A). It has been found that the feasibility of short current for the COS fuse is closely related to the porosity of the silencer.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.951-954
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• 2006

This Study introduces the design of a reactive type silencer for reducing impulse noises emitted from a high voltage COS fuse of a transformer. When a high voltage COS fuse becomes a short circuit by the over current, the peak sound pressure level above 150dB(A) is generated at the distance of 2m from a COS Fuse. For the purpose of the reduction of impulse noise, in this study. the reactive type silencers have been utilized. The performance of noise reduction for them can be expressed by insertion loss. The reactive silencers have been tested for 23 different types with each different porosity, hole diameter and depth. From the experimental results, it is found that the reactive silencer has an excellent performance to greatly suppress the impulse noise. The one-stage, two-stage and three-stage reactive type silencers have been shown to have the insertion losses of about from 35dB (A) to 25dB(A).

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.71-74
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• 2005

This experimental study describes the propagation characteristics and reduction of impulse noises emitted from a high voltage COS(Cut Out Switch) fuse of a transformer. When a high voltage COS fuse becomes a short circuit by the over current. The peak sound Pressure above 150dB(A) is generated. In this study, an impulse noise generator is designed for generating the impulse noises similar to the noise level of COS fuse, which is utilized to test the noise reduction of a reactive silencer. The reactive silencers have been tested for 10 different types with each different porosity, hole diameter and length. From the experimental results, it is found that the reactive silencer has an excellent performance to greatly suppress the impulse noise and that its performance is closely connected with the porosity and hole diameter.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.227-230
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• 2005

This paper describes the problems in measuring and evaluating the aviation noises and the differences on the noise characteristics between fighter and civil aircraft. From a standpoint of the duration time for aviation noise and the dynamic characteristics related with the sampling time, the measured values for landing and taking-off noises from the fighter are presented and explained in comparison with those from the civil aircraft. And also the aviation noises by the fighter and civil aircraft are evaluated by equivalent sound level and WECPNL, respectively. From the obtained results, it is recommended that the duration time and dynamic characteristics be deeply considered in evaluating and measuring the aviation noises, since they have a great influence on the final assessment results. As the number of flight is not sufficient and the noise source is strong impulse type, moreover, the aviation noise should be assessed by WECPNL.

• 로봇학회논문지
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• 제18권2호
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• pp.172-181
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• 2023

This paper presents research on the stability of control for a quadruped robot with two different leg structure designs. The focus of the research is on the design and analysis of the leg structures in terms of their impact on the stability and robustness of the robot's motion. First, a static analysis was performed in the simulation to compare the structural strength of the legs when the same force was applied. Secondly, two quadruped robots were built, each equipped with differently designed legs, and performed trot gait walking in the real world. And the states of the robots and the torques of each joint were analyzed and compared. In conclusion, based on the results of structural analysis in simulation and the actual walking experiments with the robots, it was demonstrated that the legs designed to be structurally robust improved the control stability of the quadruped robot.

• 전자통신동향분석
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• 제26권5호
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• pp.14-28
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• 2011

모바일 혁명과 빅데이터(big data) 시대에 접어들면서 사용자 중심의 자연스러운 인터페이스와 정보검색에 대한 요구가 늘어가고 있다. 모바일 환경에서의 쉽고 자연스러운 검색을 위해 음성인식 기술을 이용한 음성검색 서비스가 대세를 이루고 있으며 대화형 검색 서비스로 발전하게 될 것이다. 음성 대화 서비스의 주요 응용 분야인 음성검색 및 외국어 교육 서비스에서의 자연어 음성인식 기술 역할 및 사용자 경험을 바탕으로 하는 선순환 구조의 인식 성능 개선에 대해 소개한다. 또한 두 응용분야에서의 국내외 개발동향을 소개하고 실제 개발 사례를 통해 무제한급 자연어 음성인식 기술에 기반한 음성 대화 서비스의 가능성을 살펴본다.

• Tuberculosis and Respiratory Diseases
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• 제66권4호
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• pp.314-318
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• 2009

저자들은 반복적인 코출혈이 있는 가족에서 폐동정맥기형이 있는 동생과 점막의 모세혈관확장증을 가진 형을 경험하고 희귀한 유전질환인 유전출혈모세혈관확장증의 가계도를 확인하였기에 문헌고찰과 함께 보고하는 바이다.

• 대한영상의학회지
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• 제79권6호
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• pp.332-336
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• 2018

신장 동맥 손상은 둔상의 드문 합병증이나, 신장의 혈류 차단을 일으켜 신부전증을 일으킬 수도 있어 조기 진단과 치료가 필요하다. 신장 동맥 손상의 치료 방법은 아직 논란이 남아 있기는 하지만, 최근 연구들에서 혈관 내 스텐트를 이용한 성공적인 치료 결과가 보고 되었다. 그러나 아직 소아 환자에 대해서는 표준 치료법이 정해지지 않았다. 우리는 16세 여자 환아에서 발생한 4등급 간 열상과 동반된 우측 신장 동맥 폐색 증례를 보고하고자 한다. 환아는 풍선 혈관형성술만을 이용한 치료를 시행 받았고, 후에 신장의 실질 혈류 관류가 뚜렷하게 개선되었으며 신기능이 정상화 되었다. 따라서 소아 환자에서 신장 동맥 손상이 발생했을 경우, 풍선 혈관형성술을 이용한 시술이 치료의 한가지 방법이 될 수 있다.