자주포 보조동력장치 엔진 마운트 강도안전율 향상에 관한 연구

김병현,서재현,박영일,김용욱,김병호,Kim, Byung Hyun,Seo, Jae Hyun,Park, Young Il,Kim, Yong Wook,Kim, Byung Ho 한국군사과학기술학회 2016 한국군사과학기술학회지 Vol.19 No.3

The purpose of this study is to analyze the vibration characteristics and develop a mounting which can improve the strength safety factor to replace the high failure rate APU(auxiliary power unit) imported metal mounts with rubber mount that can be domestically produced. For this study, we analyzed in 3 kinds of rubber mounts hardness for the natural frequency to avoid the average excited frequency of the APU. In addition, allowed vibration acceleration of rubber mount confirmed to 90.8 g by adding a strength safety factor. To assure the validity of the design, we measure the vibration acceleration equipped with a metal mount and rubber mount 2 species(Hs 50 and 60). As a result, the proposed design method in this study is reasonable because the rubber mounts is excellent strength safety factor and vibration transmissibility than metal mounts.

K-means 알고리즘을 사용한 칼라 동영상 링잉 노이즈 감쇄 방법의 개선

김병현,장준영,장원우,최현철,강봉순,Kim, Byung-Hyun,Jang, Jun-Young,Jang, Won-Woo,Choi, Hyun-Chul,Kang, Bong-Soon 한국정보통신학회 2011 한국정보통신학회논문지 Vol.15 No.3

본 논문에서는 CODEC을 사용한 동영상의 손실 압축에 의해 발생하는 블러링 현상과 복원 과정 중 발생하는 링잉 노이즈를 감쇄하기 위한 개선된 선명도 향상 알고리즘을 제안하였다. 기존 알고리즘은 RGB 색 좌표계의 세 가지 칼라 값을 사용하는 연산으로 인해 많은 연산량을 요구한다. 이를 개선하기 위해 YCbCr 색 좌표계 중 휘도 값만을 사용하여 연산하였다. 시뮬레이션을 통해 RGB 칼라 값을 사용하는 기존 알고리즘과 휘도 성분인 Y 칼라 값만을 사용하는 개선된 알고리즘의 성능이 동등함을 확인하였다. 또한 Kodak 표준 이미지를 사용한 연산 처리 속도 측정을 통해서 개선된 알고리즘의 연산 처리 속도가 기존 알고리즘에 비해 약 24% 향상함을 확인하였다. In this paper, we proposed the improved Advanced Detail Enhancement algorithm that improve the blurring by the lossy compression with CODEC and reduce the ringing artifacts in restoration. The conventional algorithm needs much amount of the process by the use of RGB color space. To improve this, we only used the luminance value in YCbCr color space. We verified that the performance of the improved algorithm with Y color value, the luminance value, is equal to the conventional algorithm with RGB color value and that the operation time of the improved is shorter about 24% than the conventional through the measurement of the operation time with Kodak standard images.

원전기기 내진검증 기술

김병현,Kim, Byeong-Hyeon 재료연구소 1997 機械와 材料 Vol.9 No.4

CelIulase 구성 요소별 처리에 의한 펄프 섬유의 특성 변화

김병현,전양,Kim, Byung-Hyon,Jeon, Yang 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.2

Two major cellulase components purified with sephadex G-75 and DEAE sepharose were applied to bleached kraft pulp to inverstigate the change of fiber properties. Cellulose viscosity was very sensitive to $C_x$ component treatment (more than 15% drop was observed) while being little influenced by $C_1$, component (only 2% drop). Fiber fraction longer than 2mm was reduced by $C_x$ treatment while short fiber fraction was increased greatly by more than 15%. There was little change in fiber length distribution by combined treatment of $C_1$ 1 and $C_x$ at equal. In this case, fine contents increased by more than 2.5% at equivalent refining time. WRV and Density were increased as the amount of $C_1$ or $C_x$ treatment was increased. $C_{x}$ was main cause for increasing them. But the effect fell as enzyme dosage.

이미지 센서에 의해 발생하는 노이즈 제거를 위한 영상의 조도에 따른 적응적 로컬 시그마 필터의 구현

김병현,곽부동,한학용,강봉순,이기동,Kim, Byung-Hyun,Kwak, Boo-Dong,Han, Hag-Yong,Kang, Bong-Soon,Lee, Gi-Dong 한국융합신호처리학회 2010 융합신호처리학회 논문지 (JISPS) Vol.11 No.3

본 논문에서는 이미지 센서에 의해 발생하는 노이즈를 제거하기 위한 적응적 로컬 시그마 필터 장치를 제안하였다. 이미지 센서에 의해 발생하는 작은 노이즈는 이미지 센서의 아날로그 게인과 노출시간의 증가로 인해 영상 정보와 함께 증폭되며 이러한 노이즈 제거를 목표로 시스템을 설계 하였다. Flatness Index Map 알고리즘을 사용해 영상의 윤곽선을 추출하였으며, 임계치가 영상의 휘도에 따라 적응적으로 변화하도록 설계하여 고조도 영상에서는 윤곽선 추출을 수행하지 않으며, 저조도에서만 윤곽선을 추출하도록 하였다. 추출된 윤곽선을 판단하여 그에 해당하는 픽셀에 대해서만 Local Sigma Filter 알고리즘을 사용하여 노이즈 제거를 수행 하였다. 설계된 필터의 성능 검증을 위해 윈도우 테스트 프로그램을 제작하였다. 그리고 HDL을 사용해 하드웨어로 설계하였으며, FPGA Demonstration board와 $1280{\times}720$ 이미지 사이즈, 30 frame/sec의 성능을 갖는 HD급 CMOS 이미지 센서를 사용해 하드웨어로 설계된 로컬 시그마 필터의 동작을 검증하였다. In this paper, we proposed the adaptive local sigma filter reducing noises generated by an image sensor. The small noises generated by the image sensor are amplified by increased an analog gain and an exposure time of the image sensor together with information. And the goal of this work was the system design that is reduce the these amplified noises. Edge data are extracted by Flatness Index Map algorithm. We made the threshold adaptively changeable by the luminance average in this algorithm that extracts the edge data not in high luminance, but just low luminance. The Local Sigma Filter performed only about the edge pixel that were extracted by Flatness Index Map algorithm. To verify the performance of the designed filter, we made the Window test program. The hardware was designed with HDL language. We verified the hardware performance of Local Sigma Filter system using FPGA Demonstration board and HD image sensor, $1280{\times}720$ image size and 30 frames per second.

Black soldier fly (Hermetia illucens) larvae oil as an alternative fat ingredient to soybean oil in laying hen diets

김병현,Minji Kim,Jin Young Jeong,Hye Ran Kim,지상윤,정현정,Seol Hwa Park 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.9

Objective: The objective of this study was to determine whether dietary black soldier fly (Hermetia illucens, HI) larvae oil (HILO) could serve as an alternative fat source to soybean oil (SBO) in laying hen diets. Methods: We randomly assigned 25-week-old Hy-line Brown laying hens (n = 144) to receive (n = 6 hens/group; eight replicates) a control or an experimental diet in which SBO was replaced with 50% (50HILO) or 100% HILO (100HILO). Results: Dietary HILO did not negatively affect body weight or productive performance during the study. The eggs also had similar quality parameters, proximate composition, and cholesterol levels. However, the yolk color index was significantly higher (p<0.01) in the 100HILO than in the other groups. Dietary HILO significantly altered the composition of fatty acids (FAs) in abdominal fat and eggs. Total saturated fatty acids (SFAs) and total polyunsaturated FAs (PUFAs) were significantly increased and decreased in the 50HILO and 100HILO groups, respectively, compared with those in the control group (p<0.001 and p<0.0001, respectively). Specifically, the medium-chain FAs lauric and myristic acids were remarkably increased in the abdominal fat of laying hens fed HILO (p<0.0001), whereas only myristic acid increased in eggs (p<0.0001). Undesirable heavy metal (aluminum, fluorine, arsenic, lead, mercury, and cadmium) concentrations were below permissible limits in eggs. Conclusion: We considered that HILO could be an alternative dietary fat to SBO for laying hens with maintained productive performance and good egg quality.

제지 공정 적용을 위한 Cellulase의 정제 특성 및 처리 조건 선정에 관한 연구

김병현,전양,Kim, Byung-Hyon,Jeon, Yang 한국펄프종이공학회 1998 펄프.종이기술 Vol.30 No.1

The main protein peak was observed in fraction No.9 and 109 when cellulase seperation was conducted by use of DEAE-Sephadex. The protein obtained from fraction No.9 has the characteristics of Cx component and that from fraction No.109 characteristics similiar to $C_1$ component. The effective reaction condition of the ensyme used was $40^{\circ}C$ in temperature. pH 5.0 and 90 minutes in treatment time. For the case of $C_1$ pH 5.5 in temperature range of $30^{\circ}C 50^^{\circ}C$, 4.0 5.5 in pH, and over 30 minutes of treatment time, the reaction was in the range of 80% of the maximum. Affinity of enzyme increased as freeness, increased, and this effect was more visible in fiber than in fines.

통합 이미지 처리 기술을 이용한 콘크리트 교량 균열 탐지 및 매핑

김병현,조수진,Kim, Byunghyun,Cho, Soojin 한국안전학회 2021 한국안전학회지 Vol.36 No.1

In many developed countries, such as South Korea, efficiently maintaining the aging infrastructures is an important issue. Currently, inspectors visually inspect the infrastructure for maintenance needs, but this method is inefficient due to its high costs, long logistic times, and hazards to the inspectors. Thus, in this paper, a novel crack inspection approach for concrete bridges is proposed using integrated image processing techniques. The proposed approach consists of four steps: (1) training a deep learning model to automatically detect cracks on concrete bridges, (2) acquiring in-situ images using a drone, (3) generating orthomosaic images based on 3D modeling, and (4) detecting cracks on the orthmosaic image using the trained deep learning model. Cascade Mask R-CNN, a state-of-the-art instance segmentation deep learning model, was trained with 3235 crack images that included 2415 hard negative images. We selected the Tancheon overpass, located in Seoul, South Korea, as a testbed for the proposed approach, and we captured images of pier 34-37 and slab 34-36 using a commercial drone. Agisoft Metashape was utilized as a 3D model generation program to generate an orthomosaic of the captured images. We applied the proposed approach to four orthomosaic images that displayed the front, back, left, and right sides of pier 37. Using pixel-level precision referencing visual inspection of the captured images, we evaluated the trained Cascade Mask R-CNN's crack detection performance. At the coping of the front side of pier 37, the model obtained its best precision: 94.34%. It achieved an average precision of 72.93% for the orthomosaics of the four sides of the pier. The test results show that this proposed approach for crack detection can be a suitable alternative to the conventional visual inspection method.

Godunov형 모형을 이용한 2차원 홍수 모델링에서의 효율적 계산격자

김병현,Kim, Byeong-Hyeon 한국수자원학회 2015 물과 미래(한국수자원학회지) Vol.48 No.5

백남준아트센터

김병현,Kim, Byeong-hyun 대한건축사협회 2008 建築士 Vol.2008 No.10