상측분절시신경형성부전 환자와 정상안압녹내장 환자의 망막신경섬유층 두께 비교

김주현,강신희,박주현,이가영,Joo Hyun Kim,Shin Hee Kang,Joo Hyun Park,Kayoung Yi 대한안과학회 2013 대한안과학회지 Vol.54 No.2

Purpose: To analyze the peripapillary retinal nerve fiber layer (RNFL) in superior segmental optic hypoplasia (SSOH) patients and normal tension glaucoma (NTG) patients with inferior visual field defects using optical coherence tomography (OCT). Methods: Ten eyes of 10 patients with SSOH and 10 eyes of 10 patients with NTG were evaluated. The peripapillary RNFL thickness measured by OCT was compared between the 2 groups. Results: The mean RNFL thickness was not significantly different between SSOH patients (79.60 ± 12.54 μm) and NTG patients (77.10 ± 8.52 μm) (p = 0.089). Among the quadrant parameters, there were no significant differences between the 2 groups (p > 0.05). In a clock-hour analysis, the peripapillary RNFL thickness of the NTG group was significantly thicker than the SSOH group in 12, 1, and 2 o’clock (p = 0.029, 0.007, 0.043, respectively). In contrast, the peripapillary RNFL thickness of the SSOH group was significantly thicker than the SSOH group in 6, and 7 o’clock (p = 0.029, 0.007, respectively). Conclusions: Peripapillary RNFL thickness in patients with SSOH was thinner than in those with NTG in the superonasal region, but thicker in the inferotemporal region indicating a different retinal nerve fiber defect pattern between the 2 diseases.

동맥류성 골낭종 1예 보고

김주현,홍기우,김영태,Kim, Joo-Hyun,Hong, Gi-U,Kim, Yeong-Tae 대한흉부심장혈관외과학회 1977 Journal of Chest Surgery (J Chest Surg) Vol.10 No.2

Here represents a case of aneurysmal bone cyst which is very rare non neoplastic bone tumor especially in rib. The aneurysmal bone cyst usually arises from long bones of the upper and lower extemities and tt-e spine, which together account for 60 to 70 per cent of cases. In this case the tumor is found in right ninth rib on routine chest X-ray. It is resected successfully and the result is excellent.

입자론의 관점에서 본 확산과 용해 개념에 관련된 과학 교과서 및 인터넷 자료 분석과 컴퓨터 수업 보조자료의 개발

김주현,이동준,김선경,강성주,백성혜,Kim, Ju Hyun,Lee, Dong Jun,Kim, Sun Kyoung,Kang, Seong Joo,Paik, Seong Hey 대한화학회 2000 대한화학회지 Vol.44 No.6

이 연구에서는 확산과 용해에 관련된 3~12학년의 과학교과서와 여러 문헌 자료들, 인터넷 사이트들을 분석하였다. 이 자료들로부터, 교과서에 제시된 확산과 관련된 설명들이 용해, 상태변화, 분출과 혼동되어 사용되고 있었으며 매질과의 충돌 또한 고려되고 있지 않았다는 것을 알았다. 그리고 용해와 관련된 거의 모든 자료도 용해의 원리를 인력에 의한 영향으로 설명하지 못하고 있었으며, 거의 대부분 용해에 관한 설명이 개념의 이해보다는 계산 문제 풀이에 초점이 맞추어져 있었다. 또한, 각종 인터넷 사이트들도 단편적인 교과서의 나열 수준에서 벗어나지 못하였고 단지 시청각적인 효과에 치중하고 있었다. 화학이 입자론적 관점에서 자연현상을 이해해야 함에도 불구하고 대부분의 교과서와 인터넷 사이트들은 그것을 충분히 반영하지 못하고 있었다. 이에 이 연구에서는 올바른 과학적 개념을 형성하고 입자론적인 관점에서 미시세계를 거시적 자연현상과 연결시키고자 했다. 그 방법으로 움직이는 물체를 표현할 수 있는 컴퓨터의 장점을 최대한 활용하여 입자이동의 관점으로 확산과 용해와 관련된 수업보조자료를 개발하였다. In this study we analysed 3-12 grade science textbooks, many literatures and internet sites related to diffusion and dissolution concepts. From these data, we discovered that the explanations of diffusion that used in textbooks are not considered the site of collision with mediums, and confused with dissolution, state transition and effusion. In the case of dissolution, almost analysis data were short of the explanations of interaction effect. Most of all, the focus of dissolution explanations was to solve the calculation problems rather than to understand the concept. Every internet site was poor, just as the level of showing textbook contents with computer, so the only effect of using computer was the sense of sight and hearing. Chemistry must be understood nature phenomena with a view point of particle theory, but many textbooks and Internet sites didn't represent it sufficiently. We set up the correct scientific concept and linked micro world of particle theory with macro world of nature phenomena. With a use of computer which have the advantage of representing moving things, we developed the computer-assisted instruction programs related to diffusion and dissolution with the viewpoint of particle movement.

분무열분해공정에 의한 메조기공 알루미나 제조에 있어 Al 전구체 영향

김주현,정경열,박균영,Kim, Joo-Hyun,Jung, Kyeong-Youl,Park, Kyun-Young 한국분말야금학회 2010 한국분말재료학회지 (KPMI) Vol.17 No.3

Mesoporous alumina particles were prepared by spray pyrolysis using cetyltrimethyl-ammonium bromide (CTAB) as a structure directing agent and the effect of Al precursor types on the texture properties was studied using $N_2$ adsorption isotherms, small-angle X-ray scattering (SAXS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The surface area and the microstructure of alumina particles were significantly influenced by the Al precursor type. The largest BET surface area was obtained when Al chloride was used, whereas alumina particles prepared from Al acetate had the largest pore volume. According to small-angle X-ray scattering (SAXS) analysis, the alumina powders prepared using nitrate and acetate precursors had a clear single SAXS peak around $2{\theta}=1.0{\sim}1.5^{\circ}$, indicating that regular mesopores with sponge-like structure were produced. On the basis of TEM, SAXS, and $N_2$ isotherm results, the chloride precursor was most profitable to obtain the largest surface area ($265\;m^2/g$), whereas, the nitrate precursor is useful for the preparation of non-hollow mesoporous alumina with regular pore size, maintaining high surface area (${\sim}233\;m^2/g$).

중첩 기반 연산과 Hanning Window를 이용한 블록 불연속 노이즈 방지 알고리즘

김주현,장원우,박정환,양훈기,강봉순,Kim, Joo-Hyun,Jang, Won-Woo,Park, Jung-Hwan,Yang, Hoon-Gee,Kang, Bong-Soon 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.9

본 논문은 블록 처리 방법을 기반으로 하는 링잉 노이즈 감소 알고리즘을 사용할 때, 블록 불연속 노이즈(Block Discontinuty)를 방지 할 수 있는 중첩 기 반(Overlapped Block) 연산과 Hanning Window에 관련된 것이다. 링잉 노이즈 감소 알고리즘은, 24bit RGB와 블록 기반 연산으로 하며, 수정된 K-means 알고리즘을 바탕으로 한다. 그래서 제안한 중첩 기반 연산은 입력 영상을 여러 단위 블록으로 조각낼 때, 단위 블록의 크기의 반을 중첩 시켜 선택하는 방법이다. $16{\times}16$ 픽셀 크기의 데이터 블록을 데이터 유닛(Data Unit)이 라고 정의하였다. 그 후 처리된 데이터 유닛들을 등방성 분포를 지닌 Hanning Window를 사용하여 중첩된 데이터에서 원 이미지 형태로 복원하였다. 최종적으로 언급된 알고리즘의 성능을 확인하기 위해서 링잉 노이즈를 가진 이미지를 기존 방법(비 중첩 기반 연산)과 제안한 알고리즘으로 처리함으로써 각각의 결과를 비교하였다. In this paper, we propose an Overlapped Block and an Hanning Window to prevent a Block Discontinuity when we use an algorithm to eliminate ringing artifact which is based on a block structure. The algorithm to eliminate ringing artifact operates with a block structure and 24-RGB data and is based on a modified K-means algorithm. The proposed overlapped block method is piled up one on another per an half of the size of unit-block when an input image is split into several unit-blocks. Therefore, we define a data unit as the unit-block of the block size, $16{\times}16$ pixels. We reconstruct the processed data units into the original form of input image by using an isotropic form of Hanning Window. Finally, in order to evaluate the performance of the abovementioned algorithms, we compare three image, an input image with ringing artifact, an image result obtained by conventional method (non-overlapped), and an image result obtained the proposed method.

Group Delay를 이용한 모바일 기기용 고성능 해상도 확대기의 하드웨어 구현

김주현,박정환,최원태,강봉순,Kim, Joo-Hyun,Park, Jung-Hwan,Choi, Won-Tae,Kang, Bong-Soon 한국융합신호처리학회 2007 융합신호처리학회 논문지 (JISPS) Vol.8 No.3

본 논문에서는 bicubic 방법보다 하드웨어 구조는 간단하면서 확대 이미지는 더욱 선명한 polyphase scaler를 제안하였다. 제안된 시스템은 새로운 픽셀을 얻기 위해서 디지털 필터의 group delay를 이용하여 해상도를 확대하는 방식을 사용하였으며 bicubic 방법과 비교하여 더 좋은 성능을 가지면서 하드웨어 구조를 간단히 하여 모바일 기기 등에 쉽게 적용이 가능하도록 설계하였다. 기존 polyhpase 필터는 해상도 확대시 영상을 흐릿하게 하는 blurring 노이즈가 발생하는 문제점을 가지고 있었다. 그래서 입력 신호의 고주파 성분을 증폭시키도록 Polyphase 필터를 boost-up 필터로 수정하여 보다 선명한 결과를 얻을 수 있었다. 본 논문에서 제안하는 polyphase scaler는 Xilinx Virtex2 FPGA를 이용하여 하드웨어 검증을 수행하였다. 제안된 polyphase scaler는 핸드폰 카메라의 디지털 줌으로 사용되어 질 수 있다. In this paper, we propose that the polyphase scaler whose performance to that of the bicubic method, has less complexity in hardware structure. In order to get the new information, proposed system is based on the group delay which is one of the digital filter characteristics. The performance of this system is superior to that of bicubic algorithm which is well known. Because the hardware structure is simpler than other image scalers, we can adopt this system for mobile devices easily. The previous polyphase filters make blurring noise which is generated by up-scaling. We replace polyphase filters by boost-up filter to get vivid image. The proposed scaler is verified by Xilinx Virtex2 FPGA and is used as digital Boom in mobile camera phone.

직장인의 내현적 자기애가 조직 침묵에 미치는 영향에서 부정적 평가에 대한 두려움과 회피 동기의 이중매개효과

김주현,정우진,정승철,Kim, Joo-hyun,Jeong, Woo-jin,Jung, Sung-cheol 한국벤처혁신학회 2021 벤처혁신연구 Vol.4 No.1

The purpose of this study was to examine the effects of office workers' covert narcissism on organizational silence and identify the (Duel)mediation effects on fear of negative evaluation and the avoidance motivation. This study used a survey of 393 office workers to measure the covert narcissism, the organizational silence, the fear of negative evaluation and the avoidance motivation. The collected data were analyzed by IBM SPSS 23 and SPSS PROCESS macro in a Bootstrapping method. The result shows that the covert narcissism, the organizational silence, the fear of negative evaluation and the avoidance motivation have positive correlations. In addition, a simple regression analysis was used according to the research model and all of them showed adequate coefficient of determination between each variables. Next, the mediating model was verified by mediation of the fear of negative evaluation and the avoidance motivation. In the relationship between the covert narcissism and the organizational silence, the mediating effect of the fear of negative evaluation was not verified and the avoidance motive showed a partial mediating effect. Finally, in the relationship between the covert narcissism and the organizational silence, the fear of negative evaluation and the avoidance motivation were gradually mediated through the (Duel)mediation effects model, and the model was statistically significant. Through this study, The implications of this study were discussed, not only the limitations of the study but also the necessity of further research were discussed.

모바일 기기를 위한 NTSC, PAL, SECAM 비디오 인코더의 설계

김주현,양훈기,강봉순,Kim, Joo-Hyun,Yang, Hoon-Gee,Kang, Bong-Soon 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.11c

This paper presents the design of a video encoder for the device of need TV-OUT function. The designed video encoder satisfies the standard conditions of International Telecommunication Union-Radiocommunication (ITU-R) BT.470. ITU-R BT.470 can be classified as NTSC, PAL or SECAM. NTSC and PAL use Amplitude Modulation (AM) to transmit color difference signals and SECAM uses Frequency Modulation (FM). SECAM must have an antic-cloche filter but the filter recommended by ITU-R BT.470 is not easy to design due to sharpness of the frequency response. So formerly the filter was designed as analog. This paper proposes that the filter is designed as digital and the special quality of the filter is transformed easy to design. And the modulation method is modified to be identical with the result required at standard. The encoder can control power consumption by output mode to apply mobile phone, mobile devices, etc. The proposed encoder is experimentally demonstrated with ALTERA FPGA APEX20KE EP20K1000EBC652-3 device and SAMSUNG LCD-TV. 본 논문은 TV 출력 기능이 필요한 기기를 위한 비디오 인코더의 설계에 관한 것이다. 설계된 비디오 인코더는 International Telecommunication Union-Radiocommunication (ITU-R) BT.470 표준을 모두 지원한다. ITU-R BT.470에는 NTSC, PAL, SECAM의 3가지로 구분되는데, NTSC와 PAL은 색차 신호를 전송하기 위해서 진폭변조(AM)를 사용하고, SECAM은 주파수변조(FM)를 사용한다. SECAM에서는 anti-cloche 필터가 필요한데, 표준(ITU-R BT.470)에서 권장하는 필터의 특성이 아주 예리해서 이전까지는 아날로그 필터를 사용하여 설계하였다. 본 논문에서는 anti-cloche 필터를 디지털 필터로 설계하고 필터의 특성을 설계하기 쉽도록 바꾸었다. 그리고 표준에서 요구하는 결과와 동일하도록 수정된 변조 방법을 제안한다. 또한 핸드폰 등의 모바일 기기에 적용 할 수 있도록 동작 모드에 따른 소비전력을 가변 하였다. 제안된 비디오 인코더는 Altera사의 FPGA APEX20K1000-EBC652-3과 삼성 LCD-TV를 이용하여 실시간 검증을 수행하였다.

CCTV용 CCD를 위한 가변 clock으로 동작되는 비디오 인코더의 설계

김주현,하주영,강봉순,Kim, Joo-Hyun,Ha, Joo-Young,Kang, Bong-Soon 한국정보통신학회 2006 한국정보통신학회논문지 Vol.10 No.1

CCTV(Closed Circuit TeleVision)에 사용되는 CCD(Charge Coupled Device)는 일본의 소니가 시장을 $80\%$ 선점하고 있다. 이는 다른 회사가 따라오지 못할 만큼의 성능을 가지고 있기 때문인데, 문제는 CCD에서 사용되는 clock 주파수가 범용 비디오 인코더에서 사용하는 주파수와 다르다는 것이다. 이 때문에 범용 비디오 인코더를 사용하여 TV 출력을 만들려면, 화면 크기를 조절해 주는 scaler와 2개 clock의 동기를 잡아주는 PLL(Phase Loop Lock)이 필요하다. 그래서 본 논문에서는 scaler와 PLL을 사용하지 않고도 TV 출력 신호를 만들 수 있도록 CCD와 동일한 clock으로 동작하는 비디오 인코더를 제안한다. 본 비디오 인코더는 ITU-R BT.601 4:2:2, ITU-R BT.656 중 하나의 입력을 받아서 NTSC, PAL등의 S-video 신호와 CVBS(Composite Video Baseband Signals)로 바꾸어 준다. 입력 클럭이 가변하기 때문에 인코더 내부에서 사용하는 필터의 특성도 가변되도록 설계하였고 하드웨어 크기를 줄이기 위해서 곱셈기를 사용하지 않는 구조로 설계하였다. 명암 신호와 색차 신호를 위한 디지털 필터의 bit width는 하드웨어 설계 시 발생할 수 있는 오차를 ${\pm}1$ LSB(Least Significant Bit) 이하가 되도록 정하여 양질의 복합 영상 신호를 만들 수 있도록 하였다. 제안된 시스템은 Altera FPGA인 Stratix EP1S80B953C6ES을 이용하여 검증을 수행하였다. SONY corporation preoccupies $80\%$ of a market of the CCD used in a CCTV system. The CCD of SONY have high duality which can not follow the progress of capability. But there are some problems which differ the clock frequency used in CCD from the frequency used in common video encoder. To get the result by using common video encoder, the system needs a scaler that could adjust image size and PLL that synchronizes CCD's with encoder's clock So, this paper proposes the video encoder that is activated at equal clock used in CCD without scaler and PLL. The encoder converts ITU-R BT.601 4:2:2 or ITU-R BT.656 inputs from various video sources into NTSC or PAL signals in CVBS. Due to variable clock, property of filters used in the encoder is automatically changed by clock and filters adopt multiplier-free structures to reduce hardware complexity. The hardware bit width of programmable digital filters for luminance and chrominance signals, along with other operating blocks, are carefully determined to produce hish-quality digital video signals of ${\pm}1$ LSB error or less. The proposed encoder is experimentally demonstrated by using the Altera Stratix EP1S80B953C6ES device.

유연전자소자를 위한 차세대 유연 투명전극의 개발 동향

김주현,천민우,좌성훈,Kim, Joo-Hyun,Chon, Min-Woo,Choa, Sung-Hoon 한국마이크로전자및패키징학회 2014 마이크로전자 및 패키징학회지 Vol.21 No.2

Flexible transparent conductive electrodes (TCEs) have recently attracted a great deal of attention owing to rapid advances in flexible electronic devices, such as flexible displays, flexible photovoltanics, and e-papers. As the performance and reliability of flexible electronics are critically affected by the quality of TCE films, it is imperative to develop TCE films with low resistivity and high transparency as well as high flexibility. Indium tin oxide (ITO) has been the most dominant transparent conducting material due to its high optical transparency and electrical conductivity. However, ITO is susceptible to cracking and delamination when it is bent or deformed. Therefore, various types of flexible TCEs, such as carbon nanotube, conducting polymers, graphene, metal mesh, Ag nanowires (NWs), and metal mesh have been extensively investigated. Among several options to replace ITO film, Ag NWs and metal mesh have been suggested as the promising candidate for flexible TCEs. In this paper, we focused on Ag NWs and metal mesh, and summarized the current development status of Ag NWs and metal mesh. The several critical issues such as high contact resistance and haze are discussed, and newly developed technologies to resolve these issues are also presented. In particular, the flexibility and durability of Ag NWs and metal mesh was compared with ITO electrode.