• 대한방사선기술학회지:방사선기술과학
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• 제41권6호
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• pp.533-538
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• 2018

As the use of digital radiographic system has been expanded, there are some concerns an increase about in patient of radiation dose. Therefore, International Electro-technical Commission (IEC) has been proposed a standard foe exposure index (EI). In this study, the EI was measured on human chest model using computed radiography (CR). Radiation quality used RQA5 of IEC62494-1. After acquiring the chest anterior posterior image (Chest AP) by using the phantom, the EI was obtained by applying the system response. In this study, we have analyzed the images with the detector size (Full filed ROI) and the optimized image (Fit filed ROI). The EI increased proportionally with radiation dose increase. Due to the discrete increase in pixel value, the EI showed an exponential increase. The discrete increase in noise equivalent quanta (NEQ) resulted in a discrete increase in the EI. The EI of the two images used in this study increased with increasing NEQ but showed different increments. For the measurement of the EI, IEC standards must be followed. The EI should be used as an index to evaluate the image quality for quality control of X-ray image rather than as an indicator of exposure dose. When calculating the EI, the system response should be applied depending on whether or not the grid is used. The size of the field should be obtained by including only the necessary parts.

• 제어로봇시스템학회논문지
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• 제19권11호
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• pp.984-990
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• 2013

Pick and placement systems need high speeds and reliability for the position alignment process of semiconductor packages in picking up and placing them on placement trays. Image processing is usually adopted for position aligning where finding out the most suitable method is considered most important aspect of the process. This paper proposes a method for judging the performance of different image processing algorithms based on the PCI (Process Capability Index). The PCI is an index which represents the error distribution acquired from many experimental data. The bigger the index, the more reliable the results or the lower the deviation. Two compared and candidate methods are Hough Transform and PCA (Principal Component Analysis), both of which are very suitable for oblong or rectangular type packages such as BGA's. Comparing the two approaches through a CPI with enough experimental results leads to the conclusion that the PCA is much better than the Hough Transform in not only reliability, but also processing speed.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2021년도 추계학술대회
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• pp.658-660
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• 2021

본 연구의 목표는 확산 광학 단층 촬영에 대한 기준 영상을 사용하여 동질성과 이질성을 분리하기 위한 재구성된 영상들간의 수치적 평가를 위해 구조적 유사성 지수에 기초한 알고리즘을 개발한다. 글로벌 지오메트리 및 관심 영역 평가는 유사성을 산출하기 위해 측정되었으며, 그 결과 구조적 유사성 지수의 평균이 모델 내부에 가시적 포함 여부를 판단할 수 있는 잠재적 성능을 나타낸다는 것을 알 수 있으며, 구조적 유사성 지수는 유방 구조 정보를 평가하기 위한 이미지 평가를 지원 가능한 것으로 확인 되었다.

• 기본간호학회지
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• 제18권4호
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• pp.444-451
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• 2011

Background: The purpose of this study was to identify weight control behavior according to body mass index and perception of body-image, and factors that affect weight control behavior in female college students. Methods: A convenience sample of 276 female college students agreed to complete a questionnaire. Data were collected from October 5 to October 15, 2009. The data were analyzed using SPSS win 18.0 program with descriptive statistics, Chi-square test and Logistic regression. Results: According to preferred body type, 86.9% of the students who preferred slim, 13.3% who preferred their own body type, and 4.2% who preferred chubby reported using weight control behavior. For weight control behavior according to satisfaction with body type, 82.9% of the students who were dissatisfied with their body type and 52.8% who were satisfied practiced weight control behavior. Variables influencing weight control behavior were body mass index (underweight OR 1.37, p=.050), cognition of the body (chubby/fat OR 2.68, p=.047), and preferred body type (slim OR 1.29, p=.006). Conclusion: The results of this study indicate that, health providers need to educate female college students about appropriate body image and weight control behavior. Also, more studies are needed to identify other factor influencing weight control behaviors.

• Journal of Biosystems Engineering
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• 제16권3호
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• pp.272-280
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• 1991

The aims of this study were to investigate the feasivility of analyzing a few sorting factors such as size, coloration and defect of apples with a monochrome image processing system and to find apparent properties which could be effectively used for apple sorting. The results are summarized as follows. 1. A computer program was made to analyze the projection area, coloration and defect of an apple with a monochrome image processing system. 2. The algorithm developed to compute the projedtion area of an apple was between on the proportional relation between a given reference area and the corresponding number of pixels, and the computing time was 0.74 to 0.82 second depending on the size of apple. 3. The coloration of an apple was expressed as the ratio of the gray value of a reference color to that of a given bounded area of the stem end surface (defined as coloration index), and the computing time was about 3.0 seconds with this algorithm. 4. Defect of an apple could be isolated by lowpass filtering and image subtraction but it took about 20 seconds in computing time. 5. The coloration of the Fuji apple could be classified into 3 to 4 groups by the coloration index and also, it was found that the correlation coefficient between the indices and sugar contents was 0.74. 6. The coloration index obtained from a given bounded area of the stem end side of the Fuji apple could represent the coloration of total surface with a correlation coefficient of 0.922.

• 대한환경공학회지
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• 제30권2호
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• pp.168-174
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• 2008

본 논문에서는 하수처리장의 자동 계측 제어 시스템을 구축함에 있어 제한 요소로 작용되는 2차 침전조의 침전 상태를 자동으로 진단하기 위해 이미지 분석 기법을 적용한 On-line SVI(Sludge Volume Index) analyzer를 이용하였다. 침전 상태를 알아보기 위해 카메라로 촬영한 디지털 이미지로부터 RGB(Red-Green-Blue) 프로파일을 얻었으며, 이를 통해 상등수와 슬러지층의 경계를 자동으로 감지할 수 있는 SV30 감지 알고리즘을 제안하였다. 개발된 SV30 감지 알고리즘은 벌킹, 핀플럭과 같은 침전 문제 발생 시에도 신뢰성 있는 감지능을 보여주었다. 또한 본 논문에서는 상등수 부분의 RGB 값과 실제 운전자에 의해 측정된 탁도 값 사이의 상관관계를 통하여, 탁도 추정 모델을 제안하였다.

• 여성건강간호학회지
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• 제7권4호
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• pp.622-630
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• 2001

This study aims at examining relationships between body mass index and perceived body shape and image. Using a purposive sampling method, 404 female college students were recruited from three universities located in Busan from April 2000 to June 2000. To classify the levels of obesity, Broca's method was used. Secord & Jourard's Body Cathexis Scale(1953) modified by Kim mi ok(1997) was also used to measure body image. The collected data were analyzed with the percentages, Mean, Standard deviation, T-test, and Pearson correlation Coefficient. The results of this study were as follows. 1. 56.4 % of subjects were under weight, and 42.1% were normal for BMI. 2. 55.9% of subjects were very satisfied with their body shape and 15.1% were satisfied. 3. The mean values of perceived body shape according to the BMI were 3.0 for the overweight group, 2.65 for the normal weight group, and 2.21 for the low weight group, the mean differences among three groups were significantly satisfied (F= 21.42, P= .000). 4. The mean scores of body image according to the BMI was 160.21 for low weight group, 155.57 for the normal weight group, and 140.0 for overweight group. The mean differences among the three groups were not significantly satisfied. 5. The mean scores of body image according to perceived body shape were 17819 for the satisfaction group, 161.08 for the moderate group and 150.82 for dissatisfied group. The mean differences among the three groups were significantly satisfied (F= 35.72, P=. 000). 6. There were high positive correlations between BMI and perceived body shape(r= .317) and between perceived body shape and body image (r=- .415).

• Asian Journal of Atmospheric Environment
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• 제5권1호
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• pp.8-20
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• 2011

Atmospheric visibility is one of the indicators used to evaluate the status of air quality. Based on a conceptual definition of visibility as the maximum distance at which the outline of the selected target can be recognized, an image analysis technique is introduced here and an algorithm is developed for visibility monitoring. Although there are various measurement techniques, ranging from bulk and precise instruments to naked eye observation techniques, each has their own limitations. In this study, a series of image analysis techniques were introduced and examined for in-situ application. An imaging system was built up using a digital camera and was installed on the study sites in Incheon and Seoul separately. Visual range was also monitored by using a dual technology visibility sensor in Incheon and transmissometer in Seoul simultaneously. The Sobel mask filter was applied to detect the edge lines of objects by extracting the high frequency from the digital image. The root mean square (RMS) index of variation among the pixels in the image was substantially correlated with the visual ranges in Incheon and Seoul with correlations of $R^2$=0.88 and $R^2$=0.71, respectively. The regression line equations between the visual range and the RMS index in Incheon and Seoul were VR=$2.36e^{0.46{\times}(RMS)}$ and VR=$3.18e^{0.15{\times}(RMS)}$, respectively. It was also confirmed that the fine particles ($PM_{2.5}$) have more impacts to the impairment of visibility than coarse particles.

• 한국지리정보학회지
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• 제22권1호
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• pp.129-139
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• 2019

지구관측 위성영상을 활용한 도시지역 매핑 작업은 도시지역의 팽창 및 도시발전의 관측을 위해 매우 중요하다. 본 연구에서는 대구광역시를 촬영한 Landsat-8 위성영상의 분광밴드를 이용하여 제작한 두 원격탐사 지수 영상(정규 건축물 지수(NDBI) 영상 및 도시 지수 (UI) 영상) 으로부터 도시지역을 탐지하기 위한 임계점 평가에 관한 연구를 다음과 같이 진행하였다. 우선, Landsat-8 영상의 분광밴드를 이용하여 NDBI 영상과 UI 영상을 각각 제작한다. 그리고 다양한 임계점(-0.4, -0.2 및 0)을 NDBI 및 UI 영상에 적용하여 도시지역을 탐지하고, 탐지된 도시지역의 정확도를 산출한다. 본 연구를 통해 진행한 실험결과를 분석한 결과, NDBI 영상에서는 임계점으로 -0.2를 적용시켰을 때 탐지된 도시지역의 정확도(88%)가 가장 높았고, UI 영상에서는 임계점으로 -0.4를 적용시켰을 때 탐지된 도시지역의 정확도(88%)가 가장 높았다. 또한, 일부 지역에서는 나지가 도시지역으로 오분류 되었으며, 고층 아파트 지역이 비도시 지역으로 오분류 되었다. 추후 연구에서는 위성영상에서 오분류를 줄이고 다양한 도시지역 객체를 추출할 수 있는 개선된 방법을 제안하도록 한다. 또한 다중시기 위성영상에서 탐지된 도시지역을 이용하여 도시 팽창 패턴을 분석하는 추후 연구도 수행할 계획이다.

• Journal of Information Processing Systems
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• 제9권1호
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• pp.141-156
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• 2013

In this paper we propose a method to detect human faces in color images. Many existing systems use a window-based classifier that scans the entire image for the presence of the human face and such systems suffers from scale variation, pose variation, illumination changes, etc. Here, we propose a lighting insensitive face detection method based upon the edge and skin tone information of the input color image. First, image enhancement is performed, especially if the image is acquired from an unconstrained illumination condition. Next, skin segmentation in YCbCr and RGB space is conducted. The result of skin segmentation is refined using the skin tone percentage index method. The edges of the input image are combined with the skin tone image to separate all non-face regions from candidate faces. Candidate verification using primitive shape features of the face is applied to decide which of the candidate regions corresponds to a face. The advantage of the proposed method is that it can detect faces that are of different sizes, in different poses, and that are making different expressions under unconstrained illumination conditions.