• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.106-115
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• 2003

In crossing stereo camera system as a security equipment system, a new algorithm for the tracking method of the moving object and the measurement method of distance of the object from cameras to moving object is proposed. The stereo input images are matched by a pixel for the moving object extraction, then the moving elements obtained from an adaptive threshold's value for an error correction and the moving object area extracted by noise eliminative algorithm. In addition to, the moving object traced by control pan/tilt of cameras using a coordinate value of the moving object, and the measurement method of distance to moving object by using special features of the crossing stereo camera system is proposed. From the experimental results, the proposed algorithm was found to be able to measure of the distance and trace for moving object in a stereo security camera system. The error rate of a distance measurement be existed within 6%. Moreover in implementation the proposed algorithm, the stereo security system, the automatic moving robot system and the stereo remote control system will be applied practical application.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.10
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• pp.1987-1996
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• 2009

Recently, the color of vehicle license plate has been changed from green to white. Thus the vehicle plate recognition system used for parking management systems, speed and signal violation detection systems should be robust to the both colors. This paper presents a vehicle license plate recognition system, which works on both of green and white plate at the same time. In the proposed system, the image of license plate is taken from a captured vehicle image by using morphological information. In the next, each character region in the license plate image is extracted based on the vertical and horizontal projection of plate image and the relative position of individual characters. Finally, for the recognition process of extracted characters, PCA(Principal Component Analysis) and LDA(Linear Discriminant Analysis) are sequentially utilized. In the experiment, vehicle license plates of both green background and white background captured under irregular illumination conditions have been tested, and the relatively high extraction and recognition rates are observed.

• The Journal of the Korea Contents Association
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• v.9 no.9
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• pp.68-79
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• 2009

A variance map can be used to detect and distinguish texts from background in images. However, previous variance maps work at one level and they suffer a limitation in dealing with varieties in text size, slant, orientation, translation, and color. We present a method for robustly segmenting text regions in complex color Web images using two-level variance maps. The two-level variance maps work hierarchically. The first level finds the approximate locations of text regions using global horizontal and vertical color variances with the specific mask sizes. The second level then segments each text region using intensity variance with a local mask size, which is determined adaptively. By the second process, backgrounds tend to disappear in each region and segmentation can be accurate. Highly promising experimental results have established the effectiveness of our approach.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.5
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• pp.667-673
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• 2009

This paper presents an efficient facial expression recognition method by measuring the histogram distance based on preprocessing. The preprocessing that uses both centroid shift and histogram equalization is applied to improve the recognition performance, The distance measurement is also applied to estimate the similarity between the facial expressions. The centroid shift based on the first moment balance technique is applied not only to obtain the robust recognition with respect to position or size variations but also to reduce the distance measurement load by excluding the background in the recognition. Histogram equalization is used for robustly recognizing the poor contrast of the images due to light intensity. The proposed method has been applied for recognizing 72 facial expression images(4 persons * 18 scenes) of 320*243 pixels. Three distances such as city-block, Euclidean, and ordinal are used as a similarity measure between histograms. The experimental results show that the proposed method has superior recognition performances compared with the method without preprocessing. The ordinal distance shows superior recognition performances over city-block and Euclidean distances, respectively.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.455-455
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• 2016

최근 기후변화로 빈번하게 발생하는 국지성 집중호우로 인해 홍수 피해가 증가하고 있으며, 이에 따라 유량 계측 자료의 필요성이 더욱 증대되고 있다. 현재까지 하천의 홍수 유량측정은 대부분 부자법에 의해 수행되어 왔지만, 측정 작업의 위험성이나 측정 정확도에 대해 여러 문제점이 지적되고 있다. 이에 비접촉식 측정 방법으로 안전하고 측정방식이 간편하며 높은 정확도를 갖춘 표면영상유속측정법(Surface Image Velocimetry, SIV)에 대한 연구가 활발하게 진행되고 있다. 다만 표면영상유속측정법의 경우 질 좋은 영상 촬영을 위해 밝은 빛이 필요하고, 일반적으로 매우 작은 규모의 하천을 제외하고는 영상 획득이 어렵다는 한계가 있다. 이와 같은 문제들을 해결하기 위해 최근 류권규 등(2015)은 영상 획득 장비로 원적외선 카메라의 적용성을 검토한 바 있다. 원적외선 카메라의 경우 별도의 조명을 필요로 하지 않기 때문에 주야간 구분 없이 사용 가능하다는 장점이 있으며 실제 하천에서 홍수와 함께 발생하는 안개의 영향 또한 받지 않아 고정식으로 설치하여 하천 유량측정 시스템을 구성하는 좋은 대안이 될 수 있음을 강조하였다. 다만, 원적외선 카메라는 야간에 적용시 주간과 비교하여 수표면의 움직임이 느리게 분석되는 경향이 있다고 하였다. 실험 결과를 보면, 소형 프로펠러 유속계로 측정한 수표면의 유속값에 비교하여 일반 캠코더 영상으로 산정한 유속 산정 결과의 상대오차는 최대 -10%인 반면, 원적외선 카메라 영상으로 산정한 유속 산정 결과의 오차는 -9%에서 -19%(주간), -10% 에서 -23%까지의 오차 범위를 나타내는 등 일반 캠코더에 비해 원적외선 카메라의 정확도가 다소 떨어지는 결과를 나타냈으며, 이러한 문제를 해결하기 위해서는 원적외선 영상의 명암값 분포 차이를 해결하기 위해 영상 처리 기법에 대한 추가적인 연구가 필요할 것이라고 하였다. 이에 본 연구에서는 원적외선 영상에 대한 다양한 영상 개선을 통해 표면영상유속계의 유속 측정 정확도를 높이고자 하였다. 이를 위해 우선, 적정 해상도와 시간간격을 제시하였으며, 영상의 색 보정과 영상 강화 등의 영상 개선을 통해 원적외선 영상을 이용한 유속 산정 정확도를 향상하였고, 마지막으로 다양한 야간 하천 흐름 조건에 적용하여 원적외선 영상을 활용한 표면영상유속계의 유속 측정 정확도를 높이고자 하였다.

• Journal of the Korean Society of Radiology
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• v.18 no.2
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• pp.179-185
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• 2024

By applying the various energy spectrum imaging functions of DECT, To quantitatively distinguish between contrast agent and calcification, changes in image quality are analyzed by comparing CNR and SNR. We investigated the level of dose reduction during two scans and one VNC scan. As a result, contrast agent and calcification were best distinguished in the 70 keV area, CNR and SNR were excellent, and scan dose was reduced by about 26.5%. Therefore, by applying DECT, meaningful results were obtained that could visually and quantitatively distinguish between the intravascular contrast agent and the shade of calcification. If clinical research is conducted in the future considering the patient's age, gender, and body type, quantitative analysis of calcification will be possible even with intravascular contrast agent flowing in, which will have a significant effect in reducing the patient's scan dose and the burden of multiple scans.

• The korean journal of orthodontics
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• v.36 no.2 s.115
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• pp.114-124
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• 2006

The purpose of this study was to evaluate the tooth color changes of resin bonding sites and their adjacent sites on orthodontic bracket bonding. Sixty extracted sound premolars were used and the tooth color was recorded according to the CIE $L^*a^*b^*$ color system using a spectrophotometer. The tooth colors of the twenty premolars were measured and compared before bracket bonding and after removal. On a further twenty premolars, the tooth color was measured before and after only primer application. In the change of $L^*$ values, according to the bracket bonding and primer application, the lightness was decreased, and in the change of $a^*\;and\;b^*$ values, the color was changed into a more yellowish color The color differences $({\Delta}E^*)$ were calculated from the $L^*a^*b^*$ values and compared with the standard value of clinical detection $({\Delta}E^*=3.7)$. The color differences between before the bracket bonding and after removal noted exceeded the standard value and those of between before and after the primer application were not larger than the standard value. Toothbrushing was performed after application of the primer to evaluate the color changes according to the primer abrasion. As a control, toothbrushing was performed on the last twenty premolars. The color differences noted were larger than the standard value after toothbrushing. Also, to evaluate the color changes of the tooth which is exposed to sun irradiation after bracket removal, additional photoaging was performed and the color was measured for all teeth. The additional color differences after photoaging were smaller than the standard value. The above results suggest that the tooth color changes after fixed orthodontic treatment.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.39-45
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• 1990

We established HPLC method for MAs (mugineic acid and its analogous phytosiderophore) determination. It was found that major phytosiderophores existed in high heavy metal-induced rice roots were MA (mugineic acid) and DMA (2'-deoxymugineic acid). The two MAs (MA and DMA) were simultaneously secreted at maximum rate at 12 : 00-14 : 00. On the other hand, the secretion of amino acids gradually decreased from after sunrise (7 : 00) to sunset (21 : 00). Fluctuaton in daily MAs secretion had rhythmic variation which occurred at intervals of about 4 days. The stimulation of MAs secretion from the roots was attributed not only to the light/dark cycle but to the increase in temperature. Temperature variation played a more important role than a photoperiod in MAs secretion from the roots. The initiation time of MAs secretion was positively correlated with rising time in temperature($20-30^{\circ}$) during the dark period.

• Journal of Korea Multimedia Society
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• v.8 no.11
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• pp.1496-1509
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• 2005

In this paper, an adaptive license plate recognition system which detects and recognizes license plate at real-time by using projected plane convolution and Decision Tree Classifier is proposed. And it was tested in circumstances which presence of complex background. Generally, in expressway tollgate or gateway of parking lots, it is very difficult to detect and segment license plate because of size, entry angle and noisy problem of vehicles due to CCD camera and road environment. In the proposed algorithm, we suggested to extract license plate candidate region after going through image acquisition process with inputted real-time image, and then to compensate license size as well as gradient of vehicle with change of vehicle entry position. The proposed algorithm can exactly detect license plate using accumulated edge, projected convolution and chain code labeling method. And it also segments letter of license plate using adaptive binary method. And then, it recognizes license plate letter by applying hybrid pattern vector method. Experimental results show that the proposed algorithm can recognize the front and rear direction license plate at real-time in the presence of complex background environments. Accordingly license plate detection rate displayed $98.8\%$ and $96.5\%$ successive rate respectively. And also, from the segmented letters, it shows $97.3\%$ and $96\%$ successive recognition rate respectively.

• Science of Emotion and Sensibility
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• v.12 no.1
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• pp.121-128
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• 2009

The article reports findings on: (1) development of emotion assessment scale in evaluating the Television(TV) picture quality; and (2) how psychological and physical factors relate to TV picture quality. A total of 152 adjectives that specifically describe emotional reactions were first selected from a Korean dictionary of adjectives, followed by ratings on their suitability for the evaluation of TV picture quality. The final selection of 19 adjective, based on the reported rating scores greater than 4.1, were used on 126 college students who were asked to perform similarity ratings on the adjectives. Based on factor analyses (i.e., principal component analysis with oblique rotation) on the similarity of scores, the following adjectives were selectively chosen for the development of the new emotion assessment scale: 'neat-messy', 'refreshing-gloomy', 'clean-dirty', 'comfortable-tense', 'smooth-rough', 'bright-dark', 'gorgeous-plain', 'diverse-monotonous', 'satisfying', 'natural', and 'sensuous'. These adjectives composed into two distinct constructs, 'cleanness or smart' factor and 'gorgeousness' factor, which demonstrated sensitivity to changes in brightness, contrast, color, and tint in the TV picture quality, except for changes in sharpness.