• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.1
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• pp.36-43
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• 2001

Recently, outdoor lighting of buildings has bemIre activated in national level of Korea. Therefore, this study aims to analyze the outdoor ljghting effect of historic buildings with particular reference to two traditional gates architecture - Namdaemtul and Kwanghwamun For the purpose, luminance and chromaticity of outdoor lighting are measured. The results of the study are as follows; $\circled1$ Outdoor lighting of the historic buildings were mainly illuminated by the floodlights. In addition, up-lighting and accent lighting were locally used. $\circled2$ Basements and rooflines were specially emphasized, and they represented the night image of historical buildings. $\circled3$ Chromaticity distribution of historical building was wlute during the day. However, it was yellow dL1Jing the night due to the color and color temperature of outdoor lighting.ghting.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.847-852
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• 2010

Text in natural images has a various and important feature of image. Therefore, to detect text and extraction of text, recognizing it is a studied as an important research area. Lately, many applications of various fields is being developed based on mobile phone camera technology. Detecting edge component form gray-scale image and detect an boundary of text regions by local standard deviation and get an connected components using Euclidean distance of RGB color space. Labeling the detected edges and connected component and get bounding boxes each regions. Candidate of text achieved with heuristic rule of text. Detected candidate text regions was merged for generation for one candidate text region, then text region detected with verifying candidate text region using ectilarity characterization of adjacency and ectilarity between candidate text regions. Experctental results, We improved text region detection rate using completentary of edge and color connected component.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.297-297
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• 2010

KSTAR 토카막의 두번째 실험 캠페인 동안 고속파 전자가열 (FWEH)을 위한 ICRF 고주파입사 실험을 실시하였다. 토로이달 자기장은 2 T, 플라즈마 전류는 200-300 kA, 주반경은 1.8 m, 부반경은 0.5 m의 원형 플라즈마가 가열 대상이 되었으며, 네개의 ICRF 안테나 전류띠 가운데 중심부의 두개의 전류띠를 최대 300 kW로 구동하기 위한 운전 주파수는 44.2 MHz가 선택 되었다. 이 주파수는 플라즈마의 모든 영역에서 이온 사이클로트론 공명을 일으키지 않으므로 플라즈마에 흡수되는 대부분의 출력은 전자에게 전달될 것으로 기대되었다. 낮은 고주파-플라즈마 결합으로 인하여 전송선의 최대 고주파 전압이 허용치를 초과하기 때문에 비교적 낮은 최대 출력만이 허용 되었으나, ECE에 의해 관측된 전자의 온도는 국지적으로 최대 150 % 까지 증가하는 것을 확인 할 수 있었다. 낮은 고주파-플라즈마 결합의 첫번째 원인은 FWEH의 효율이 이온을 가열할 때 보다 상대적으로 낮기 때문이다. 플라즈마 내에 이온 사이클로트론 공명층이 형성되면 높은 효율로 고주파를 입사 할 수 있다는 것은 잘 알려진 사실이다. 또다른 원인은 D 형상의 플라즈마에 맞도록 만들어진 안테나와, 원형 플라즈마간의 부조화로 인하여 고속파 차단층이 (Fast Wave Cutt-off Layer) 평균적으로 넓게 형성되기 때문이다. 플라즈마 외곽에 반드시 존재하는 낮은 플라즈마 밀도의 고속파 차단층 내부에서, 중심부로 향하는 고주파의 진폭은 지수함수로 감쇠하므로 가능하면 플라즈마 밀도를 높여 차단층 자체의 폭을 줄이거나, 안테나 전류띠를 플라즈마에 바짝 접근시켜야만 한다. 고주파 진단 장치로는 송출기의 출력과 반사파 측정 장치, 공명루프의 전압 측정 장치가 있는데, 이것들을 이용하여 안테나에 전달되는 출력 및 고주파-플라즈마 결합 효율을 나타내는 플라즈마에 대한 고주파 부하 저항을 구할 수 있다. 측정 결과, 부하 저항의 최소값은 진공시 또는 ICRF만의 방전시의 값 0.25 Ohm 보다 큰 0.5 Ohm을 나타냈으며, 최대값은 플라즈마의 상태에 따라 1 Ohm에서 2 Ohm 사이에서 매우 빠르게 요동하는 것을 확인했다. Mm 파 반사계의 측정에 의하면 플라즈마 언저리의 위치가 약 3 cm 정도의 크기로 요동하는 것으로 나타났는데, 부하 저항과 언저리 위치의 파형이 정확하게 일치하지 않지만 유사한 경향성을 가진 것으로 보인다. 따라서 플라즈마 언저리 위치의 제어를 통하여 가열 효율을 높게 유지할 수 있음을 알 수 있다. 본 발표에서는 실험의 소개와 함께 부하 저항의 관점에서 가열 효율을 높일 방안을 토론하도록 한다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.525-534
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• 2018

Camera calibration is the process of determining the parameters such as the focal length of a camera, the position of a principal point, and lens distortions. For this purpose, images of checkerboard have been mainly used. When targets were automatically recognized in checkerboard image, the existing studies had limitations in that the user should have a good understanding of the input parameters for recognizing the target or that all checkerboard should appear in the image. In this study, a methodology for automatic target recognition was proposed. In this method, even if only a part of the checkerboard image was captured using rectangles including eight blobs, four each at the central portion and the outer portion of the checkerboard, the index of the target can be automatically assigned. In addition, there is no need for input parameters. In this study, three conditions were used to automatically extract the center point of the checkerboard target: the distortion of black and white pattern, the frequency of edge change, and the ratio of black and white pixels. Also, the direction and numbering of the checkerboard targets were made with blobs. Through experiments on two types of checkerboards, it was possible to automatically recognize checkerboard targets within a minute for 36 images.

• Progress in Medical Physics
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• v.10 no.2
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• pp.63-71
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• 1999

For the purpose of utilization in 3-D conformal radiotherapy and whole body radiosurgery, the Whole Body 3-Dimensional Topographic Radiation Therapy System has been developed. Whole body frame was constructed in order to be installed on the couch. Radiopaque catheters were engraved on it for the dedicated coordinate system and a MeV-Green immobilizer was used for the patient setup by the help of side panels and plastic rods. By designing and constructing the whole body frame in this way, geometrical limitation to the gantry rotation in 3-D conformal radiotherapy could be minimized and problem which radiation transmission may be altered in particular incident angles was solved. By analyzing CT images containing information of patient setup with respect to the whole body frame, localization and coordination of the target is performed so that patient setup error may be eliminated between simulation and treatment. For the verification of setup, the change of patient positioning is detected and adjusted in order to minimize the setup error by means of comparison of the body outlines using 3 CCTV cameras. To enhance efficiency of treatment procedure, this work can be done in real time by watching the change of patient setup through the monitor. The method of image subtraction in IDL (Interactive Data Language) was used to visualize the change of patient setup. Rotating X-ray system was constructed for detecting target movement due to internal organ motion. Landmark screws were implanted either on the bones around target or inside target, and variation of target location with respect to markers may be visualized in order to minimize internal setup error through the anterior and the lateral image information taken from rotating X-ray system. For CT simulation, simulation software was developed using IDL on GUI(Graphic User Interface) basis for PC and includes functions of graphic handling, editing and data acquisition of images of internal organs as well as target for the preparation of treatment planning.

• Korean Journal of Environment and Ecology
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• v.27 no.2
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• pp.253-265
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• 2013

This study was correlation analysis between provision and management of street green and street environment through field survey about city official roads(93 routes, 629.2km) in Seoul. Green belt under the street trees were 17.5% of all routes. Composition of street green belt width of 1~ 2m was the most common(11.6%). Management status as a protected facilities were protect frame and prtect cover installed inerval(60.1%). Interval of pruning was 63.5%. Type of tree was mainly 47.9%. Road width was mainly more than 8-line(51.3%). Sidewalk width was mainly 3~6m(84.1%)in environment status of street. Landuse was mainly commercial and business(70.3%). Electronic wire complete was mainly compete with crown(33.6%). Use of sidewalk was mainly used(16.3%). ANOVA analysis was conducted between the Street green and environment of Street. Street green belt(more than with 3m) was analyzed to be effective in street green manufacture. Natural green area of city's outside and Industrial area were analyzed to be effective. Use of sidewalk was to be a management. Protection facilities are installed on the narrow sidewalk width lower intensity. There was a higher strength in narrow sidewalk width, road width and compete with crown. And type of tree was higher strength similarly. Pruning and type of tree showd a significant correlation. Thus, ensure sufficient sidewalk width and land use should be considered for street green was effective manufacture and management. Species selection and pruning management was needed by consider electronic wire management, type of tree and landscape.

• Economic and Environmental Geology
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• v.53 no.2
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• pp.197-212
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• 2020

This study was carried out material characteristics and firing conditions for some potteries in early and middle Neolithic period at the Munamri sites, where the first farmland remails were found in Korea. It is divided into six kinds of surface patterns for potteries such as the raised, bamboo tube and red painted (patternless) from the early Neolithic period (BC 4000 to 6000), and the patterns of horizontal herringbone, short slanted lined or lattice and incised thick line in the middle Neolithic period (BC 3000 to 4000), respectively. Based on the color measures, redness and yellowness of potteries were relatively high as condition of oxidation firings, were also observed black cores on the cross section of potteries. The firing temperature is divided into two groups having under 800℃ and 800to 900℃, the difference in patterns of the potteries are not confirmed. As a microtextures, the bamboo tube pattern potteries show the sericitization biotite, the quartz have developed a suture line textures, and altered alkali feldspars are occurred. X-ray diffraction analysis shows that the main minerals contained in potteries are chlorite and amphibole besides quartz, alkali feldspar and biotite. Considering the geology around the Munamri area is the biotite amphibole granite and soil layers within 10km radius are used as the raw materials for the potteries. The raw materials are presumed that the sources from the metamorphic rocks along the water systems through the mountains around the sites on the basis of well developed suture line textured quartz in potteries. Results on normalized geochemical compositions, the potteries by surface patterns are very similar to sources, and it is judged that was made by using the surrounding soils despite the long time difference from the early to middle in the Neolithic period.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.11-16
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• 2023

In preclinical positron emisson tomography(PET), spatial resolution degradation occurs outside the field of view(FOV). To solve this problem, a depth of interaction(DOI) detector was developed that measures the position where gamma rays and the scintillator interact. There are a method in which a scintillation pixel array is composed of multiple layers, a method in which photosensors are arranged at both ends of a single layer, a method in which a scintillation pixel array is constituted in several layers and a photosensor is arranged in each layer. In this study, a new type of DOI detector was designed by analyzing the characteristics of the previously developed detectors. In the two-layer detector, different sizes of scintillation pixels were used for each layer, and the array size was configured differently. When configured in this form, the positions of the scintillation pixels for each layer are arranged to be shifted from each other, so that they are imaged at different positions in a flood image. DETECT2000 simulation was performed to confirm the possibility of measuring the depth of interaction of the designed detector. A flood image was reconstructed from a light signal acquired by a gamma-ray event generated at the center of each scintillation pixel. As a result, it was confirmed that all scintillation pixels for each layer were separated from the reconstructed flood image and imaged to measure the interaction depth. When this detector is applied to preclinical PET, it is considered that excellent images can be obtained by improving spatial resolution.

• Journal of Internet Computing and Services
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• v.16 no.2
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• pp.49-55
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• 2015

According to the statistics of traffic accidents over recent 5 years, traffic accidents during the night times happened more than the day times. There are various causes to occur traffic accidents and the one of the major causes is inappropriate or missing street lights that make driver's sight confused and causes the traffic accidents. In this paper, with smartphones, we designed and implemented a lane luminance measurement application which stores the information of driver's location, driving, and lane luminance into database in real time to figure out the inappropriate street light facilities and the area that does not have any street lights. This application is implemented under Native C/C++ environment using android NDK and it improves the operation speed than code written in Java or other languages. To measure the luminance of road, the input image with RGB color space is converted to image with YCbCr color space and Y value returns the luminance of road. The application detects the road lane and calculates the road lane luminance into the database sever. Also this application receives the road video image using smart phone's camera and improves the computational cost by allocating the ROI(Region of interest) of input images. The ROI of image is converted to Grayscale image and then applied the canny edge detector to extract the outline of lanes. After that, we applied hough line transform method to achieve the candidated lane group. The both sides of lane is selected by lane detection algorithm that utilizes the gradient of candidated lanes. When the both lanes of road are detected, we set up a triangle area with a height 20 pixels down from intersection of lanes and the luminance of road is estimated from this triangle area. Y value is calculated from the extracted each R, G, B value of pixels in the triangle. The average Y value of pixels is ranged between from 0 to 100 value to inform a luminance of road and each pixel values are represented with color between black and green. We store car location using smartphone's GPS sensor into the database server after analyzing the road lane video image with luminance of road about 60 meters ahead by wireless communication every 10 minutes. We expect that those collected road luminance information can warn drivers about safe driving or effectively improve the renovation plans of road luminance management.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.409-421
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• 2022

Achieving a highly resolved spatial distribution of Mn-bearing minerals and elements in the natural ferromanganese nodules can provide detailed knowledge of the temporal variations of geochemical conditions affecting the formation processes of nodules. While a recent study utilizing Raman spectroscopy has reported the changes in the manganate mineral phases with growth for spherical nodules from the Arctic Sea, the distributions of minerals and elements in the nodules from the shallow Arctic Sea with non-spherical forms have not yet fully elucidated. Here, we reported the micro-laser Raman spectra with varying data acquisition points along three different profiles from the center to the outermost rim of the non-spherical ferromanganese nodules collected from the East Siberian Sea (~73 m). The elemental distributions in the nodule (such as Mn, Fe, etc.) were also investigated by energy dispersive X-ray spectroscopy (EDS) analysis to observe the internal structure and mineralogical details. Based on the microscopic observation, the internal structures of a non-spherical nodule can be divided into three different regions, which are sediment-rich core, iron-rich substrate, and Mn-Fe layers. The Raman results show that the Mn-bearing mineral phases vary with the data acquisition points in the Mn-Fe layer, suggesting the changes in the geochemical conditions during nodule formation. In addition, we also observe that the mineral composition and structural characteristics depend on the profile direction from the core to the rim. Particularly, the Raman spectra obtained along one profile show the lack of Fe-(oxy)hydroxides and the noticeably high crystallinity of Mn-bearing minerals such as birnessite and todorokite. On the other hand, the spectra obtained along the other two profiles present the presence of significant amount of amorphous or poorly-ordered Fe-bearing minerals and the low crystallinity of Mn-bearing minerals. These results suggest that the diagenetic conditions varied with the different growth directions. We also observed the presence of halite in several layers in the nodule, which can be evidence of the alteration of seawater after nodule formation. The current results can provide the opportunity to obtain detailed knowledge of the formation process and geochemical environments recorded in the natural non-spherical ferromanganese nodule.