• 한국항공우주학회지
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• 제49권3호
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• pp.251-262
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• 2021

최근 세계적으로 연구개발이 활발히 진행되고 있는 PAV(Personal Air Vehicle)에 대한 낙뢰 간접 영향성 인증 지침의 중요성이 부각되고 있다. 미래 교통수단으로서 소형화, 전기 엔진 사용, 복합재 사용 증가, 무인 항법 시스템 적용하는 추세인 PAV는 낙뢰에 취약할 수밖에 없다. 본 연구에서는 미연방항공청(FAA)에서 발행한 AC 20 136B에 나타난 낙뢰 간접 영향에 대한 적합성 인증절차를 확인하였다. 이와 함께 RTCA DO 160G Sec. 22에 수록된 장비 과도 설계 수준에 대한 인증 지침을 PAV에 적용하였다. 이어서 SAE ARP 5416A에 수록된 항공기 수준 시험을 전자기 해석 소프트웨어 EMA3D을 통해 수행하였다. 이를 통해 PAV에 대한 실제 과도 수준을 분석하였으며 이를 통해 적합성 인증에 필요한 자료를 도출하였다.

• 한국정보통신학회논문지
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• 제23권11호
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• pp.1384-1390
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• 2019

본 논문은 머신비전기반 자동검사를 위한 대상객체의 인식방향성 개선 연구로서, 영상카메라에 의한 자동 비전검사의 과정에서 제한성이 따르는 대상 객체의 인식방향성을 개선하는 방법을 제안한다. 이를 통하여 머신비전 자동검사에서 시험대상물의 위치와 방향에 상관없이 검사대상의 영상을 검출할 수 있게 함으로써 별도 검사지그의 필요성을 배제하고 검사과정의 자동화 레벨을 향상시킨다. 본 연구에서는 검사대상으로서 와이어 하네스 제조과정에서 실제 적용할 수 있는 기술과 방법을 개발하여 실제 시스템으로 구현한 결과를 제시한다. 시스템구현 결과는 공인기관의 평가를 통하여, 정밀도, 검출인식도, 재현률 및 위치조정 성공률에서 모두 성공적인 측정결과를 얻었고, 당초 설정하였던 10종류의 컬러구별 능력, 1초 이내 검사시간, 4개 자동모드 설정 등에서도 목표달성을 확인하였다.

• 한국컴퓨터정보학회논문지
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• 제29권1호
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• pp.77-84
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• 2024

본 논문에서는 컴퓨터 비전을 사용하여 6가지 측정값(눌린 단자의 길이, 단자 끝의 치수(폭), 눌린부분(와이어 부분, 코어 부분)의 폭)을 계산하여 와이어 하네스의 결함을 정확하고 빠르게 탐지할 것을 제안한다. 두 가지 유형의 데이터에서 Harris 코너 검출을 활용하여 물체의 위치를 탐지하고 측정 영역별 특징과 배경과 물체 사이의 음영 차이를 활용하여 각 샘플의 기울기를 반영하는 측정값을 추출하기 위한 기준점을 생성한다. 이후 유클리드 거리 방법과 보정 계수를 사용하여 예측값을 계산하는 방법을 통해 와이어의 위치 변화에 관계 없이 측정값을 예측할 수 있다. 각 측정 유형별로 99.1%, 98.7%, 92.6%, 92.5%, 99.9%, 99.7% 정확도를 달성하였으며, 모든 측정값에서 평균 97%의 정확도로 우수한 결과를 얻었다. 해당 검사 방법은 기존 검사 방법인 육안 검사의 문제점을 보완하고, 작은 양의 데이터만을 이용하여 우수한 결과를 도출 가능하다. 또한 이미지 처리만 이용하기 때문에 딥러닝 방법보다 더 적은 데이터와 비용으로 적용 가능할 것으로 기대된다.

• IMMUNE NETWORK
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• 제9권4호
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• pp.115-121
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• 2009

Natural killer (NK) cells play key roles in innate and adaptive immune defenses. NK cell responses are mediated by two major mechanisms: the direct cytolysis of target cells, and immune regulation by production of various cytokines. Many previous reports show that the complex NK cell activation process requires de novo gene expression regulated at both transcriptional and post-transcriptional levels. Specialized un-translated regions (UTR) of mRNAs are the main mechanisms of post-transcriptional regulation. Analysis of posttranscriptional regulation is needed to clearly understand NK cell biology and, furthermore, harness the power of NK cells for therapeutic aims. This review summarizes the current understanding of mRNA metabolism during NK cell activation, focusing primarily on post-transcriptional regulation.

• 한국환경보건학회지
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• 제25권3호
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• pp.7-12
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• 1999

Bioremediation is the technology to harness nature's biodegradative capabilities to remove or detoxify pollutions that threaten public health as environmental contaminants. Composting may become one of major bioremediation technologies for treating soils contaminated with petroleum if the fate of contaminants during composting is better understood Most composting research of petroleum was primarily focused on removing contaminant by optimizing composting conditions. Accordingly, laboratory feasibility studies may be useful to establish a realistic basis in co-composting complex substrate such as petroleum hydrocarbons. The purpose of this study was to assess the optimal conditions of kerosene biodegradation following supplementation with nutrient amendments under simulated composting conditions. Although it increased the growth of bacterial consortium, addition of co-substrates 0.5%(w/v) such as acetic acid, citric acid, glucose, and malic acid was not beneficial. Combination of nitrogen and phosphorous source enhanced kerosene biodegradation and reduced VOC evolution. These results showed that kerosene was able to utilize in bioremediation technology.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2661-2665
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• 2011

In order to evaluate the structural integrity of a GFRP composite bogie frame due to flying railway ballast, the low velocity impact test and compressive test after impact was conducted for glass fiber/epoxy 4-harness satin woven laminate composites applied to skin part of a bogie frame. The impact test was performed using a instrumented impact testing system with energy levels of 5J, 10J and 20J and the designed impactor based on typical railway ballast shapes such as sphere, cube and cone to simulate the ballasted track environments. The compressive strength was tested to according to ASTM D7137 to evaluate the degradation of mechanical property of impact damaged laminate composites. The results showed that the damage area and the degradation of compressive strength after impact for laminate composites was increased with increase in impact energy for all ballast shapes and was particularly most influenced by cone ballast shape.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.238.2-238.2
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• 2010

Recently, environmental pollution and energy depletion problems have been issued over the world. For this reason, many renewable systems have been developing. Of these, the Ocean Thermal Energy Conservation(OTEC) is drawing attention as the upcoming alternative energy source. In this paper, the efficiency of each of OTEC which harness the effluent from nuclear power plant was analyzed by using computer calculation. The result, shows that Ul-jin Nuclear Power Plant is the best place geographically and the regenerative cycle is most outstanding performance cycle for OTEC. The difference of temperature between surface water and deep water temperature should be greater than $20^{\circ}C$ in order to increase the efficiency.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.753-757
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• 2004

This paper describes a PC-based distributed multi-rate realtime control system using USB protocol, which is developed as a general motion controller. The control system consists of two control programs: one running at 1 kHz sampling rate on a PC with Linux and another running at 10 kHz sampling rate on a remotely located motion control card called RASID (remote axis serial interface device). Two programs communicates through USB at every 1 msec. A USB communication driver is developed to ensured the 1 msec desired communication time. The main program running on the PC generates reference trajectory at 1 kHz and send it to the RASID through USB and RASIDs located near the motors gather the sensor information and execute the low-level control at 10 kHz. The USB-based connectivity reduces the wiring harness and eventually the manufacturing cost of the machine. The multi-rate nature of the developed system improves the control capability. The effect of sampling rate is analyzed and simulated.

• 대한임베디드공학회논문지
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• 제12권6호
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• pp.351-358
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• 2017

The most common communication interface for automotive electronic control devices is CAN (Controller Area Network). Sine CAN was first adopted to Daimler vehicles in 1991, all of automobile manufacturers use the CAN communication for in-vehicle networks. However, as the number of electronic control devices connected to the CAN network rapidly increases, the CAN protocol reaches the limit of technology. To overcome this limitation, Bosch introduced the new communication protocol, that is CAN-FD (Flexible Data-rate). In this paper, we analyze the characteristics and limitations of CAN-FD communication according to the topology under the in-vehicle wiring harness environment designed based on the existing classic CAN communication.

• 대한기계학회논문집
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• 제18권8호
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• pp.2053-2061
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• 1994

The static and fatigue tensile tests have been conduted to predict the fatigue life of 8-harness satin woven and plain woven carbon/epoxy composite plates containing a circular hole. A fatigue residual strength degradation model, based on the assumption that the residual strength for unnotched specimen decreases monotonically, has been applied to predict statistically the fatigue life of materials used in this study. To determine the parameters(c, b and K) of the residual strength degradation model, the minimization technique and the maximum likelihood method are used. Agreement of the converted ultimate strength by using the minimization technique with the static ultimate strength is reasonably good. Therefore, the minimization technique is more adjustable in the determination of the parameter and the prediction of the fatigue life than the maximum likelihood method.