진공주조법에 의한 TiNi 형상기억합금 강화 6061Al 지적 복합재료의 계면 및 인장 특성

박광훈,박성기,신순기,박영철,이규창,이준희,Park, Gwang-Hun,Park, Seong-Gi,Sin, Sun-Gi,Park, Yeong-Cheol,Lee, Gyu-Chang,Lee, Jun-Hui 한국재료학회 2001 한국재료학회지 Vol.11 No.12

We investigated the change of mechanical properties for TiNi shape memory alloy by heat treatment. 6061Al matrix composites with TiNi shape memory alloy as reinforcement were fabricated by vacuum casting. TiNi alloy has the maximum tensile strength at 673K treated and there is no change of tensile strength and hardness at 448K treated. The composites, prepared by vacuum casting, showed good interface bonding by vacuum casting. It was about 3$\mu\textrm{m}$ of thickness of the diffusion layer. Tensile strength of the composite was in higher than that of 6061Al alloy as increased value of about 70MPa at room temperature and about 110MPa at 363K. We thought that the increase of the tensile strength at 363K was due to reverse transformation of the TiNi shape memory alloy.

SOFM 신경망 분류기를 이용한 MPEG-4 비디오 전송률 제어

박광훈,이윤진,Park, Gwang-Hoon,Lee, Yoon-Jin 한국정보과학회 2002 정보과학회논문지 : 소프트웨어 및 응용 Vol.29 No.7

This paper introduces a macroblock-based rate control algorithm using the neural classifier based in Self Organization feature Maps (SOFM). In contrast to the conventional rate control methods based on the mathematical rate distortion (RD) model and the feedback regression, proposed method can actively adapt to the rapid-varying image characteristics by establishing the global model for bitrate control and by using the SOFM based neural classifier to manage that model. Proposed rate control algorithm has 0.2 dB ~ 0.6 dB better performances than MPEG-4 macroblock-based rate control algorithm by evaluating with the encoded Peak Signal to Noise Ratios while maintaining similar overall computational complexity. 본 논문에서는 SOFM기반 신경망 분류기를 이용한 매크로블록 기반 전송률제어 방식을 제안한다. 수학적 왜곡 비트율 모델과 귀환회기 방식을 기반으로 하는 기존의 전송률 제어 방법에 비하여, 제안된 방법은 전송비트 제어용 전역모델을 설정하고 이를 최적으로 제어할 수 있는 SOFM기반 신경망 분류기를 이용하여 영상특성 변화에 적극적인 대처를 할 수 있다. 제안된 전송률 제어 알고리즘은 기존의 MPEG-4 매크로블록 기반 전송률 제어 알고리즘에 비해 전체 연산 복잡도는 비슷하게 유지하면서 피크신호 대 잡음비의 비교에 있어서 0.2 dB ~ 0.6 dB 정도 성능이 우수함을 확인하였다.

진공 Hot Press법에 의한 TiNi/6061Al 지적 복합재료의 확산층 형성거동

박광훈,박성기,신순기,이준희,Park, Kwang-Hoon,Park, Sung-Ki,Shin, Soon-Gi,Lee, Jun-Hee 한국재료학회 2002 한국재료학회지 Vol.12 No.12

2.7vol%TiNi/6061 Al composites with TiNi shape memory alloy as reinforcement were fabricated by vacuum hot press. It was investigated by OM, SEM, EPMA and XRD analysis for the behavior of diffusion layer formation on various heat treatment condition. Thickness of diffusion layer was increased proportionally according to heat treatment time. The layer was formed by the mutual diffusion of TiNi and Al. The diffusion rate from TiNi fiber to Al matrix was faster than that of reverse diffusion path. The more diffused layer was formed in Al matrix. The diffusion at interface layer was consisted of $A1_3$Ti, $Al_3$Ni analyzed by EPMA, XRD results.

폐과오종(肺過誤腫)의 일치험례(一治驗例)

박광훈,지정희,Park, Gwang-Hun,Ji, Jeong-Hui 대한흉부심장혈관외과학회 1976 Journal of Chest Surgery (J Chest Surg) Vol.9 No.2

Since. its first description by Albrecht in 1904 that hamartoma (Greek. meaning "error" and "tumor")is tumor-like malformation characterized by abnormal mixture of normal constituent in any organ it arises, hamartoma involving the lung has assumed the following clinical features.: 1) all the pulmonary lesions presenting as "coin lesions", it occupies about 8% according to various reports. It also constitutes the most prevalent lesion of all the benign lung tumors, appearing in 0.25% of the general population. 2) Peak incidence of the lesion occurs in the 5th and 6th decade as the carcinoma patient do, and the occasional growing tendency and periperal location as in this presentation renders the differential diagnosis from the malignant disease difficult and surgical intervention inevitable for definite histological diagnosis and treatment. 3) Nearly all the clinical investigations such as history, physical exam, bronchoscopy, culture, and cytological exam of sputum sre likely to futile:the only tool for detecting the presence of the lesion is X-ray, butthat's short of telling the true nature of it. 4) Because of its age of presentation and growing tendency in middle-aged adult, it still controversial whether it is developmental anomaly as Albrecht described, or true neoplasm denovo of fibrous connective tissue origin. This is a case report of surgical experience of pulmonary hamartoma which had nearly all the typical clinical features above mentioned and was reviewed with related literatures.

MPEG에 대하여

박광훈,Park Gwang-Hun 한국공학교육학회 1997 Ingenium(人材니움) Vol.4 No.1

함께하는 삶 II - 민간 의료기관 RNA 정량검사 시행에 대한 어느 감염인의 소리

박광훈,Park, Gwang-Hun 대한에이즈예방협회 2009 레드리본 Vol.83 No.-

RNA 정량검사는 혈중 바이러스 농도를 측정하는 검사로, 감염인의 투약과 치료에 필수적인 검사로써 감염인이라면 $3{\sim}6$개월 간격으로 정기적으로 받는 검사이다. 그동안 국가에서 시행해 왔던 RNA 정량검사가 2009년 7월 1일자로 민간 의료기관에서 시행된다. RNA 정량검사를 민간 의료기관에서 실시하게 됨에 따라 감염인의 진료비 부담이 증가하게 된다. 병원에 따라서는 감염인의 비급여 본인부담금을 고려하여 특진료를 가산하지 않는 병원도 있으나 이는 극히 일부 병원에 불과한 실정이다.

Agrobacterium radiobacter K84에 의한 장미 뿌리혹병의 생물적 방제

박광훈(Kwang-Hoon Park),차재순(Jae-Soon Cha) 한국농약과학회 2001 농약과학회지 Vol.5 No.3

Severe crown gall disease was occurred in green house cultivating rose in Jinchen, Chungbuk recently. Although it causes problem on rose cultivation, the growers do not have many choices of control measures for the disease now. Agrobacterium radiobacter K84 has been known as a strong antagonist against A. tumefaciens, a pathogen causing crown gall disease, and used as a biopesticide for crown gall in many countries since it had been introduced in 1972. We tested control activity of A. radiobacter K84 for the crown gall disease on rose. Spray of A. radiobacter K84 suspension on above ground of rose either before or after pathogen spray reduced size and fresh weight of galls significantly. Size and fresh weight of galls on roses inoculated with pathogen either before A. radiobacter K84 spray (pathogen-K84 treatment) or after A. radiobacter K84 spray (K84-pathogen treatment) were 4 to 5% of those of galls on roses inoculated pathogen only. Disease incidence of plants inoculated pathogen only was 85% whereas disease incidence of pathogen-K84 or K84-pathogen treatments were 6.7% and 5.0% respectively. Dipping of roots of rose in suspension of A. radiobacter K84 was also reduced size of galls and diseased rate significantly. These results indicate that A.' radiobacter K84 is effective in the prevention of gall formation by A. tumefaciens and it can be used to control of crown gall disease of rose.

램제트 연소실 내부의 슬롯 막냉각에 따른 열전달 특성

박광훈(Park K.H),이건우(Lee K.W),조형희(Cho H.H),함희철(Ham H.C),배주찬(Bae J.CH),Oh M.K 한국유체기계학회 2006 유체기계 연구개발 발표회 논문집 Vol.- No.-

The slot film cooling technique has been used to protect a chamber wall from hot combustion gas. This method has been applicable toramjet combustor and gas turbine. Especially, the multi-slot film cooling method is mainly applicable in the ramjet operating undersupersonic condition. This experimental study has been conducted to investigate effects of a recirculation zone and a lip thickness to slot height ratio on a multi-slot film cooling in the ramjet combustor. A pre-diffuser typed ramjet combustor having a recirculation zone due to the expansion step has been used for this study.

AC방식 PHC Pile의 분체조성에 따른 양생 단계별 압축강도 특성 평가

박광훈(Park, Kwang Hoon),백승재(Baek, Seung Jae),송용순(Song, Yong Soon),허홍기(Hur, Hong Ki) 한국콘크리트학회 2016 한국콘크리트학회 학술대회 논문집 Vol.28 No.2

H.264 기반 선택적인 미세입자 스케일러블 코딩 방법

박광훈(Gwang Hoon Park),유원혁(Won Hyuck Yoo),김규헌(Kyuheon Kim) 한국정보과학회 2004 정보과학회 컴퓨팅의 실제 논문지 Vol.10 No.4

본 논문에서는 선택적으로 강화계층의 시간적 예측 정보를 사용하는 H.264 기반 선택적인 미세입자 스케일러블 비디오 코딩 방법을 제안한다. 제안된 방법의 기본계층은 최근 표준화되었으며 고압축률이 특징인 H.264 (MPEG-4 Part 10 AVC) 알고리즘으로 코딩한다. 강화계층은 기본적으로 국제표준인 비트플레인 기반 MPEG-4 (Part 2) 미세입자스케일러블 코딩 방법으로 코딩한다. 본논문에서는 엔코더측에서 강화계층간 시간적 예측 방법에 의해 발생된 효과적인 영상 정보를 드리프트 현상이 최소화 하는 방향으로 선택적으로 적용하여 디코더측에 전송하는 방안을 제안하였다. 강화계층간 예측 방법만을 추가했을 때는 시간적 중복성을 줄여주는 효과를 볼 수 있지만 저비트율 대역에서 엔코더와 디코더간의 참조 저장영상 불 일치로 인한 드리프트 현상이 심하게 발생한다. 제안된 알고리즘은 시간적 예측 결과가 우수하여 코딩효율을 현저히 높혀줄 수 있는 경우에만 선택적으로 강화계층간의 시간적 예측 정보를 사용하였으며, 이로 인하여 저비트율 대역에서의 드리프트 현상을 현저하게 줄일수 있었으며, 전반적으로 코딩 효율을 높여주는 효과를 가져왔다. 여러 영상 시퀀스를 대상으로 실험한 결과, 제안된 코딩 방법은 현존하는 국제표준인 MPEG-4 기반 미세입자 스케일러블 코딩 방법보다 같은 비트율 대역에서 영상화질이 약 3~5 dB 높은 성능을 보여주고 있으며, H.264를 기반으로한 미세입자 스케일러블 코딩 방법보다도 약 1~3 dB 높은 성능을 보여주고 있음을 발견할 수 있었다. This paper proposes the H.264-based selective fine granular scalable (FGS) coding scheme that selectively uses the temporal prediction data in the enhancement layer. The base layer of the proposed scheme is basically coded by the H.264 (MPEG-4 Part 10 AVC) visual coding scheme that is the state-of-art in codig efficiency. The enhancement layer is basically coded by the same bitplane-based algorithm of the MPEG-4 (Part 2) fine granular scalable coding scheme. In this paper, we introduce a new algorithm that uses the temproal prediction mechanism inside the enhancement layer and the effective selection mechanism to decide whether the temporally-predicted data would be sent to the decoder or not. Whenever applying the temporal prediction inside the enhancement layer, the temporal redundancies may be effectively reduced, however the drift problem would be severly occurred especially at the low bitrate transmission, due to the mismatch bewteen the encoder’s and decoder’s reference frame images. Proposed algorithm selectively uses the temporal-prediction data inside the enhancement layer only in case those data could siginificantly reduce the temporal redundancies, to minimize the drift error and thus to improve the overall coding efficiency. Simulation results, based on several test image sequences, show that the proposed scheme has 1~3 dB higher coding efficiency than the H.264-based FGS coding scheme, even 3~5 dB higher coding efficiency than the MPEG-4 FGS international standard.