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현장유출영상을 활용한 표면영상유속계(SIV)의 상관계수 분석 (Analysis on Correlation Coefficient of Surface Image Velocimeter (SIV) Using On-site Runoff Image)

  • 김용석;양성기;김동수;김서준
    • 한국환경과학회지
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    • 제24권4호
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    • pp.403-414
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    • 2015
  • This study is daytime and nighttime runoff image data caused by heavy rain on May 27, 2013 at Oedo Water Treatment Plant of Oedo-Stream, Jeju to compute runoff by applying Surface image velocimeter (SIV) and analyzing correlation according to current. At the same time, current was comparatively analyzed using ADCP observation data and fixed electromagnetic surface current meter (Kalesto) observed at the runoff site. As a result of comparison on resolutions of daytime and nighttime runoff images collected, correlation coefficient corresponding to the range of 0.6~0.7 was 6.8% higher for nighttime runoff image compared to daytime runoff image. On the contrary, correlation coefficient corresponding to the range of 0.9~1.0 was 17% lower. This result implies that nighttime runoff image has lower image quality than daytime runoff image. In the process of computing current using SIV, a rational filtering process for correlation coefficient is needed according to images obtained.

영상 평면을 이용한 PCB의 EMI 감쇠 분석 (EMI Reduction by PCB Image Planes)

  • 김진석;이애경;조광윤
    • 한국전자파학회지:전자파기술
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    • 제6권4호
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    • pp.28-36
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    • 1995
  • PCB의 전자파 복사는 전자 회로 설계에서 중요한 문제로 부각되고 있는데, PCB의 전자파 복사를 감소시키는 한 방법으로 영상 평면의 사용이 고려되고 있다. 본 논문은 PCB 전류 라인의 전자파 복사에 미치는 영상평면의 영향을 해석한 것으로, 전류 라인 아래, 위로 한 층 및 두 층식 영상 평면을 둔 구조에 대해 수치해석적으로 영상 평면에 의한 전자파 감쇠효과를 계산 하였다. 영상 평면에 유도되는 전류 분포를 모멘트 기법을 이용 하여 구했으며 전자파 복사 패턴을 서로 다른 영상 평면 구조와 비교하였고, 영상 평면의 폭과 전류 라인과 영상 평면 가이의 간격 및 신호 전류의 주파수가 최대 복사 전계에 미치는 영향을 분석하였다.

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SAR 위성영상 해수유동 정보추출 및 활용 (Analysis and application of ocean currents information extracted from SAR satellite image)

  • 이문진;김혜진;이승현;홍기용
    • 해양환경안전학회지
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    • 제13권4호
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    • pp.21-26
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    • 2007
  • 인공위성영상을 이용한 해양정보 추출을 위하여 SAR 위성영상을 이용한 해수유동 정보 추출을 연구하였다. SAR(Synthetic Aperture Radar) 위성영상의 도플러 쉬프트 정보를 이용한 해수유동 정보 추출은 적용기술의 근본적 한계로 인하여 실제 유속이 아니라 위성궤도의 법선방향에 대한 유속장도만을 제시하는 문제가 있다. 이러한 한계 및 문제점을 극복하기 위하여 본 연구에서는 위성영상 촬영과 동일한 시간에 동일한 해역에서 해수유동을 관측하고, 관측된 해수유동 정보를 이용하여 위성영상에서 추출된 해수유동 정보를 보완 검증하였다. 위성영상 추출 해수유동정보의 위성궤도 법선방향 유속강도는 관측된 해수유동 유향분포도에 근거하여 실제 해수유동 유향에 맞게 보정될 수 있었으며, 보정된 해수유동 정보는 실제 해수유동 분포를 잘 반영할 수 있었다.

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청소년들의 체형에대한 관심과 인식에 관한 조사연구 -밀양시를 중심으로- (A Survey of Adolescents' Concern and Perception about Body Image)

  • 류호경
    • 대한지역사회영양학회지
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    • 제2권2호
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    • pp.197-205
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    • 1997
  • This study was conducted to investigate adolescents' body size and their concerns and perceptions about body image. Group means of heights and weights were 171.5cm and 60.3kg for boys and 159.3cm and 52.3Kg for girls. Body Mass Index(BMI) of the subjects were 20.5 for boys and 20.6 for girls. Only 11.5$\%$ of subjects were overweight or obese, however 42.5% of subjects had experienced weight control, and the main reason for weight control was to lose weight(80.6$\%$). In concern for body image and frequency of eating distrubance ; females had more concern than males, the group who had attempted weight control had more concern than those who had not, and the group who were overweight had more concern than those who were under and normal weight. In perception about body image, using a set of nine figure drawings arranged from very thin to very heavy figures, subjects rated their current figure, considered figure(how they appeared to others), ideal figure, and attractive figure. For boys, the current, ideal, and most attractive figures were almost identical, but for girls, the ideal figure was significantly thinner than current figure and attractive figure was significantly thinner than current figure. The greater the preference for thinner figure as idal and attractive figure, the higher the concern for body image and frequency of eating distrubance. Thus it seems that a distorted perception of ideal body size affects adolescents' concern for body image and eating behaviors.

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구내 촬영용 엑스선 장치의 관전류에 따른 영상 평가 (Image Evaluation according to Tube Current of X-ray Device for Intraoral Imaging)

  • 김아연;조병두;이승재
    • 한국방사선학회논문지
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    • 제17권4호
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    • pp.515-521
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    • 2023
  • 치과 구내 촬영 시 사용하는 관전류 및 시간에 따라 환자가 받는 피폭선량은 달라진다. 영상의 질을 위해서는 많은 양의 관전류가 필요하지만, 환자에게 부여되는 방사선량은 그만큼 높아진다. 이에 본 연구에서는 시뮬레이션을 통한 치과 구내 촬영 시 사용하는 관전류에 따른 영상의 질 평가를 통해 영상의 질을 확보하면서 환자가 받는 피폭선량은 감소시킬 수 있는 최적의 관전류 양을 산출하였다. 치과 구내 촬영의 진단참고수준 가이드라인에 제시된 평균 관전류와 시간 및 관전압을 기본 촬영 조건으로 사용하고, 관전류만 변화시켰을 때 영상을 획득한 후 기본 영상과의 영상의 질 비교·분석을 통해 최적의 관전류 양을 산출하였다. 기본 조건은 63 kV, 6 mA, 0.29 s로 하고 관전류를 0.1, 0.5, 1, 2, 3, 4, 5 mA로 변경시켜 영상을 획득하였다. 획득한 영상은 ICY 프로그램을 사용하여 6 mA의 조건으로 촬영한 영상과 구조적 유사지수를 평가하였다. 그 결과 0.5 mA의 관전류 조건에서도 6 mA의 영상과 구조적 유사지수가 높은 것으로 평가되었다. 이러한 결과를 바탕으로 치과 구내 촬영 시 6 mA가 아닌 0.5 mA로 촬영한다면 환자에게 부여되는 피폭선량을 매우 감소시킬 수 있을 것으로 판단된다.

대구 및 대구근교지역 여대생과 여고생들의 체형인식, 섭식행동 및 건강상태 비교 (Perception of Body Image, Eating Disorder, Eating Behaviors and Subjective Health Status of Female High School and College Students in Daegu Area)

  • 류호경;박정아
    • 한국지역사회생활과학회지
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    • 제13권3호
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    • pp.69-80
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    • 2002
  • This study was conducted to investigate the relationship among body image Perception, eating behavior and health status in young females. The survey was carried out by self-questionnaires for 293 female high school students(HS) and 164 female college students(CS) living in Daegu and suburbs of Daegu. For the perception of body image, 9-grade body figure drawings were used based on average Korean body size. EAT-26 and Rosenberg Self-Esteem Scale were used to measure the tendency of eating disorder and self-esteem. It appeared that 40.5% of the subjects were off the normal range of body weight; especially 34.2% of the subject were underweight. The subjects' perception about current body image was within normal range. Almost of all the subjects believed that the ideal body image was thinner than their own current body image, and they wanted to be thinner than their current body image. The change of eating behaviors related to weight control of CS was significantly higher than that of HS students. EAT-26 score, self-esteem score, and subjective health status score were no difference between groups. The cut-off point of the eating disorder in this study was equal to or greater than 20 in EAT-26 score. The rates of the eating disorder were very high as 9.6% of HS and 8.5% of CS. Eating disorder was positively correlated with BMI, current body image, dissatisfaction of body image and the change score of eating behavior. But eating disorder was negatively correlated with health status. From the results of this study, we suggested that one of causes related to the eating disorder behaviors in adolescent females was resulted from misperception about ideal body image. There is a great need to provide nutrition educations concerning appropriate perception of body image and weight control among adolescent females.

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Research on chinese college students' perception of korean image

  • Xiaoyue Song;Jinling Wan
    • 국제교류와 융합교육
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    • 제2권2호
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    • pp.9-33
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    • 2022
  • This paper mainly studies the national impression of college students on South Korea, selects students from some key universities as the target population, and conducts an in-depth investigation from the overall impression of South Korea, diplomatic image, food culture, language culture, tourism, entertainment circle and other aspects. Through a questionnaire survey of Chinese college students, this paper studies the image of South Korea in the eyes of contemporary Chinese college students, including the following aspects: First, Research the current Chinese college students' perception of the overall image of South Korea; Second, it studies the current Chinese college students' perception of the image of South Korea in the diplomatic, language, food, tourism and entertainment circles, and analyzes the internal dimensions of the image of South Korea in the minds of Chinese college students; Third, it studies the current Chinese college students' cognition of the overall image of South Koreans, and analyzes the internal dimensions of the image of South Koreans in the minds of Chinese college students; Fourth, to investigate the evaluation of Chinese college students on the image of South Korea. The survey results are analyzed from the perspectives of all subjects and gender differences, combined with the theories of communication and intercultural communication, and suggestions and prospects for the future development of the national image are made.

Image Path Searching using Auto and Cross Correlations

  • Kim, Young-Bin;Ryu, Kwang-Ryol
    • Journal of information and communication convergence engineering
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    • 제9권6호
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    • pp.747-752
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    • 2011
  • The position detection of overlapping area in the interframe for image stitching using auto and cross correlation function (ACCF) and compounding one image with the stitching algorithm is presented in this paper. ACCF is used by autocorrelation to the featured area to extract the filter mask in the reference (previous) image and the comparing (current) image is used by crosscorrelation. The stitching is detected by the position of high correlation, and aligns and stitches the image in shifting the current image based on the moving vector. The ACCF technique results in a few computations and simplicity because the filter mask is given by the featuring block, and the position is enabled to detect a bit movement. Input image captured from CMOS is used to be compared with the performance between the ACCF and the window correlation. The results of ACCF show that there is no seam and distortion at the joint parts in the stitched image, and the detection performance of the moving vector is improved to 12% in comparison with the window correlation method.

Wide Dynamic Range CMOS Image Sensor with Adjustable Sensitivity Using Cascode MOSFET and Inverter

  • Seong, Donghyun;Choi, Byoung-Soo;Kim, Sang-Hwan;Lee, Jimin;Shin, Jang-Kyoo
    • 센서학회지
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    • 제27권3호
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    • pp.160-164
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    • 2018
  • In this paper, a wide dynamic range complementary metal-oxide-semiconductor (CMOS) image sensor with the adjustable sensitivity by using cascode metal-oxide-semiconductor field-effect transistor (MOSFET) and inverter is proposed. The characteristics of the CMOS image sensor were analyzed through experimental results. The proposed active pixel sensor consists of eight transistors operated under various light intensity conditions. The cascode MOSFET is operated as the constant current source. The current generated from the cascode MOSFET varies with the light intensity. The proposed CMOS image sensor has wide dynamic range under the high illumination owing to logarithmic response to the light intensity. In the proposed active pixel sensor, a CMOS inverter is added. The role of the CMOS inverter is to determine either the conventional mode or the wide dynamic range mode. The cascode MOSFET let the current flow the current if the CMOS inverter is turned on. The number of pixels is $140(H){\times}180(V)$ and the CMOS image sensor architecture is composed of a pixel array, multiplexer (MUX), shift registers, and biasing circuits. The sensor was fabricated using $0.35{\mu}m$ 2-poly 4-metal CMOS standard process.

A Low Dark Current CMOS Image Sensor Pixel with a Photodiode Structure Enclosed by P-well

  • Han, Sang-Wook;Kim, Seong-Jin;Yoon, Eui-Sik
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제5권2호
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    • pp.102-106
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    • 2005
  • A low dark current CMOS image sensor (CIS) pixel without any process modification is developed. Dark current is mainly generated at the interface region of shallow trench isolation (STI) structure. Proposed pixel reduces the dark current effectively by separating the STI region from the photodiode junction using simple layout modification. Test sensor array that has both proposed and conventional pixels is fabricated using 0.18 m CMOS process and the characteristics of the sensor are measured. The result shows that the dark current of the proposed pixel is 0.93fA/pixel that is two times lower than the conventional design.