• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.375-376
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.735-736
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• 2008

• 한국해안해양공학회:학술대회논문집
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• 한국해안해양공학회 2002년도 한국해안해양공학발표논문집 Proceedings of Coastal and Ocean Engineering in Korea
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• pp.162-176
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• 2002

태음-태양-지구 체계의 상호인력에 의해 발생하는 해양조석은 해수면의 주기적인 승강운동으로서 고체 지구상에서는 지구의 응력 및 중력장의 교란을 야기하는 변동하중을 의미한다. 해양조석에 대한 연구는 심해 및 천해역에서 정확한 조석예보를 위해서 뿐만 아니라 신뢰성 있는 해면변위(sea surface topography)를 추정하기 위해 중요하다. (중략)

• 전력전자학회논문지
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• 제4권4호
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• pp.325-331
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• 1999

계통연계형 태양광발전시스템에서는 계통과 태양광시스템을 연계하기 위해 PWM 인버터가 이용된다. 인버터 시스템을 연속전류모드로 운전하면 맥동이 발생하게 되고, 직류전류의 맥동발생은 교류전류파형의 왜형을 가져온다. 본 연구에서는 직류입력전류의 맥동을 감소시키기 위하여 불연속모드 승강압초퍼로 인버터를 운전한다. 직류 전류에 포함된 고조파성분을 리플성분과 직류성분으로 분리하여 해석하고, 맥동이 없는 일정한 직류전류를 태양 전지로부터 인버터로 공급한다. 제안하는 인버터시스템은 단위 역률로 부하와 계통에 교류전류를 공급한다.

• 한국기계가공학회지
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• 제6권3호
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• pp.85-91
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• 2007

This study was carried out to minimize the lifting force of a two hinge type stand mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment and maintenance at any preferred position. The unit will be very useful for the mechanism fabricated with a coil spring and disc springs as a torque generator. The maximum and the minimum torque value should be calculated initially for the smooth lift. And the reasonable torque distribution is necessary to prevent any auto lift and auto dropping at any position because the torque generated by coil spring is more sensitive than disc spring in tilting the position. Therefore, the analysis of the coil spring is requisite to issue the specific torque value depending on the distorted angle with securing reliability of a long time storage condition. After the theoretical torque value was calculated, the evaluation was carried out by making a proto-type sample, then distorted angle was updated by experiment. The result of this study can readily be applied to various units for the optimization of the smooth lift.

• 대한한의학원전학회지
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• 제29권2호
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• pp.91-119
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• 2016

Objectives : In this paper, the main objective is to analyze and evaluate Kim Gwangjin(金光鎭, 1885-1940)'s academical achievements of integration of eastern with western medicine and innovation of traditional medicine(TM, 漢醫). Methods : This paper is composed of two parts. First, analyzing Kim's medical book, the principle of Up and Down in Medicine(醫學升降法) by the way of text analysis and interpretation faithfully. Second, adding historical perspectives about his achievements. Results : Kim opened a clinic and practiced TM in Daegu, a city of Youngnam(嶺南) area of Korea, in 1924, and published the book in 1936. While Kim acknowledged the scientific results by western medicine and criticized the typical explanation of five viscera or qi circuits of TM, he clarified the treatment range for TM and provided his own interpretations of pathophysiology through the ups and downs of qi, without conflicting between western medicine and TM. Moreover, he critically follows the TM discourses of the most noted practitioner, Lee Gyoojoon(李圭晙), in the Youngnam area of the time. Conclusions : In the 1930s, although western medicine has become the new core orientation and has forced out TM to the districts, within the abyss of the districts, TM still maintained its strong presence.

• 대한전자공학회논문지
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• 제27권2호
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• pp.111-117
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• 1990

본 논문에서는 스위칭 레귤레이터의 한 형태인 승강압형 DC-DC 콘버어터에 있어서 전달함수의 우반면에 존재하는 영점이 안정성에 대하여 미치는 영향을 고찰하였고, 출력전류의 변화에 대한 안정범위를 궤한이득을 통하여 구하였다. 이 결과로부터, 우반면에 영점이 존재하기 때문에 안정성이 저하됨을 알 수 있었다. 궤한제어회로에 극 보상을 하였고, 이경우 유효한 안정성의 범위를 이득대역폭적과 관련지어 구하였으며 실험을 통하여 이를 입증하였다.

• 한국산업융합학회 논문집
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• 제21권6호
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• pp.361-368
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• 2018

This paper proposes a grid - connected CTTS system that can be soft switched to meet the government's effective resource allocation policy for emergency generator. In order to eliminate the system instability caused by the large inrush current generation in the system switching, a new virtual rotation coordinate method for the dissimilar power source is proposed. The proposed virtual rotation coordinate method improves the voltage detection accuracy of the voltage difference of the dissimilar power supply, and it is proved that the synchronous switching characteristic is excellent. In addition, zero current and system stabilization can be achieved by realizing zero current when blocking CTTS with instantaneous reactive power control. Simulation was carried out to verify the validity of the proposed method, and the 500[kVA] system was fabricated and verified to demonstrate the superiority of the proposed method.

• 한국산업융합학회 논문집
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• 제22권3호
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• pp.251-257
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• 2019

This paper proposes a new measurement method using virtual power concept to measure the effective value of 3-phase voltage with variable frequency. The conventional effective value measurement method uses a method of integrating data sampled during one or half cycle of the power voltage and averaging it. In this method, since the effective voltage is calculated every cycle, a time delay occurs in the measured effective voltage and it is s a problem to measure the effective value of a device whose frequency varies from time to time, such as a generator. The proposed 3-phase voltage rms measurement method has an advantage that it can measure accurate voltage RMS value regardless of measurement frequency variation. In particular, there is an advantage in that it is possible to measure a 3-phase effective voltage rather than an average value of the effective voltage of each phase in a 3-phase unbalance voltage. In addition, the validity of the proposed method is verified by using the Psim simulation tool and the experimental results are analyzed by applying the proposed measurement algorithm to the actual three phase synchronous generator voltage measurement experiment.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2021년도 춘계학술발표대회
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• pp.263-266
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• 2021

근래의 드론 산업은 다양한 분야에서 사용이 확대되고 있으나 규제 등 여러 가지 사회적 진입장벽으로 시장 진입에 애로사항이 도출되고 있다. 본 논문에서는 드론 산업의 여러 제약 중 배터리의 제한적인 용량으로 장시간 비행이 어려운 문제를 개선하고자 승강식 드론스테이션을 개발하였다. 승강식 드론스테이션은 드론의 비행 중 배터리가 방전될 시 충전 및 정비를 할 수 있고, 드론 간의 통신 중계기 역할을 수행한다. 본 논문에서는 스테이션에 드론이 접근 시 슬라이딩 도어를 개폐하기 위하여 초광대역 통신을 이용한 거리 측정과 위치 인식 시스템에 대한 내용을 기술하였다.