• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1645-1652
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• 2018

A drone which was developed first for military purpose has been expanded to various civil areas, with its technological development. Of the drones developed for such diverse purposes, a drone for photography has a camera installed and is actively applied to a variety of image contents making, beyond filming and broadcasting. A drone for photography makes it possible to shoot present and dynamic images which were hard to be photographed with conventional photography technology. This study made a view finder which helps a drone operator to control a drone and directly view an object to shoot with the drone camera. The view finder for drones is a type of glasses. It was developed in the way of printing out the data modelled with 3D MAX in a 3D printer and installing a ultra-small LCD monitor. The view finder for drones makes it possible to fly a drone safely and achieve accurate framing of an object to shoot.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.6
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• pp.645-653
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• 2020

Recently studies on how to use the UAV (Unmanned Aerial Vehicle) are actively being conducted, and the National Geographic Information Institute published the 『Work Guidelines for Public Surveying of Unmanned Aerial Vehicles』. However, the guidelines do not provide the optimum shooting conditions required for each application. In this study, we tried to find the suitable shooting conditions for the production of 3D (Three-dimensional) spatial information and orthophoto. To this end, 45 experiments were conducted by various altitudes, overlaps, and camera angles within an above ground level of 150m. For evaluating the 3D modeling by shooting conditions, point densities of 9 verification areas were analyzed, and to evaluate the orthophotos, 1/1,000 digital maps were compared. Considering the quality of the output and the processing time for precise 3D construction, an altitude of 50m, an overlap of 70~80%, and a camera angle of 80~90° are suitable as shooting conditions, and an altitude of 100m and camera angle of 80~90° are suitable for orthophoto generation.

• Journal of radiological science and technology
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• v.40 no.3
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• pp.355-361
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• 2017

Pediatrics are more sensibility to radiation than adults and because they are organs that are not completely grown, they have a life expectancy that can be adversely affected by exposure. Therefore, the management of exposure dose is more important than the case of adult. The purpose of this study was to determine the suitability of the 10 year old phantom for the 5 year old pediatric's recommendation and the incident surface dose, and to measure the organ absorbed dose. This study is compared the organ absorbed dose and the entrance surface dose in the clinical conditions at 5 and 10 years old pediatric. Clinical 5 year old condition was slightly higher than recommendation condition and 10 year old condition was very high. In addition, recommendation condition ESD was found to be 43% higher than the ESD of the 5 year old group and the ESD of the 10 year old group was 126% higher than that of the 5 year old group. The recommended ESD at 5 years old and the ESD according to clinical imaging conditions were 31.6%. There was no significant difference between the 5 year old recommended exposure conditions and the organ absorbed dose due to clinical exposure conditions, but there was a large difference between the Chest and Pelvic. However, it was found that there was a remarkable difference when comparing the organ absorbed dose by 10 year clinical exposure conditions. Therefore, more detailed standard exposure dose for the recommended dose of pediatric should be studied.

• Journal of dental hygiene science
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• v.4 no.3
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• pp.97-102
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• 2004

In order to find out the rate of error according to intraoral standard radiographic techniques, this study analyzed 3,251 standard films, and conducted a questionnaire with 120 Daegu Health College students who have used the bisecting angle technique and the paralleling technique. Followed are the results of the study: 1. The rate of error was the highest in canine from both maxilla and mandible when used by the bisecting angle technique. 2. The rate of error was the highest in premolar from both maxilla and mandible when used by the paralleling technique. 3. The technical error was occurred most frequently in elongation. 4. The rate of error and distortion was higher in the bisecting angle technique than in the paralleling technique. 5. The processing error was occurred most frequently in light film. 6. In applying radiographic techniques, the subjects indicated that the vertical angulation of central radiation in the bisecting angle technique and the oral fixation of film holder in the paralleling technique were the most difficult.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.223-228
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• 2008

In order to acquire the images requested by users, it is very important to calculate mission schedule parameters such as imaging execution time and attitude tilt angle accurately. These parameters are based on orbit prediction. This paper describes the accuracy of orbit propagation for image planning. The orbit prediction data from PSS and MAPS has a certain discrepancy due to different orbit propagator. It is necessary for mission planner to confirm this value during mission planning phase. The pointing error which means the difference between target center and real image received is calculated and analyzed using KOMPSAT-2 image data.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.103-112
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• 1986

The purpose of this study was to investigate the numbers and causes of retakes in 300 complete mouth radiographic surveys made by 75 senior dental students. According to radiographic techniques and film holding methods, they were divided into 4 groups: Group Ⅰ: Bisecting-angle technique with patient's fingers. Group Ⅱ: Bisecting-angle technique with Rinn Snap-A-Ray device. Group Ⅲ: Paralleling technique with Rinn XCP instrument (short cone) Group Ⅳ: Paralleling technique with Rinn XCP instrument (long cone) The most frequent cause of retakes, the most frequent tooth area examined, of retakes and average number of retakes per complete mouth survey were evaluated. The obtained results were as follows: Group Ⅰ: Incorrect film placement(47.8%), upper canine region, and 0.89 Group Ⅱ: Incorrect film placement (44.0%), upper molar region, and 1.12. Group Ⅲ: Incorrect film placement (79.2%), upper molar region, and 2.05 Group Ⅳ: Incorrect film placement (67.7%), upper molar region, and 1.69. The average number of retakes per complete mouth survey of paralleling technique (Group Ⅲ＋Ⅳ) was higher than that of bisecting-angle technique (Group Ⅰ ＋ Ⅱ) (p<0.01). There was no difference between Group Ⅰ and Group Ⅱ, and between Group Ⅲ and Group Ⅳ in the average number of retakes per complete mouth survey (p>0.05).

• Journal of radiological science and technology
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• v.31 no.2
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• pp.171-175
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• 2008

The aim of this study is to assess the dose reduction of eye lens and availability of bismuth garments resulting from the use of radioprotective bismuth garments to shield the eyes of patients undergoing head CT. Rando phantom and TLDs were used to determine the amount of dose reduction by bismuth shielding of the eye in the following simulated CT scans : (a) scanning of the head including orbits, (b) scanning of the whole head, and (c) $20^{\circ}$ angled scanning of the head excluding orbits. The average dose reduction of eye lens was 43.2%, 36.0% and 1.4% for the three CT scans listed above. Significant reduction in the eye lens dose was achieved by using superficial orbital bismuth shielding during head CT scans. However, bismuth shields should not be used for the patients when their eyes are excluded from the primarily exposed region.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.217-223
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• 2022

In this study, images taken using a grid and images taken using Air Gap Technique were evaluated in X-ray chest radiography. Subjective Evaluation The ROC (Receiver Operating Characteristic) evaluation was evaluated by 5 radiologists who had worked for more than 10 years in the radiology department of a university hospital. Objective evaluation SNR (Signal to noise ratio) was evaluated. As a result of the analysis, the Cronbach Alpha value was 0.714, which was significantly higher. In the Air Gap Technique, the distance between the phantom and the subject was set at 20 cm, and the image was taken with a tube voltage of 100 kVp, a tube current and a recording time of 8 mAs. In the ROC (Receiver Operating Characteristic) evaluation, the highest score was obtained with 18 score and an objective evaluation SNR (signal to noise ratio) of 6,149 scored. Also, in the imaging method using a grid, when the distance between the phantom and the constant receptor is 15 cm apart, and the tube voltage is 110 kVp, the tube current and the recording time are taken at 8 mAs, the ROC evaluation score is 19 and the objective evaluation SNR (Signal to noise ratio) is the highest with 6.622 scored. Therefore, if the Air Gap Technique imaging method is used, which overcomes the shortcomings such as delay in reading, increase in patient's exposure dose, and shortening of mechanical lifespan, as well as re-radiography due to the cut-off phenomenon of the grid that appears using the grid, the It is thought that it will be very helpful for chest imaging, including the case of using a portable X-ray imaging device.

• Korean Association of Arts Management
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• no.49
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• pp.37-63
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• 2019

This study aims to find out how the photographing affects the satisfaction of visitor experience in the art gallery. We surveyed the visitors who visited the exhibition hall. In order to see if the selfie photographs positively affect the visitor satisfaction level, one-way ANOVA was conducted and the mediating effect of the flow and the moderating effect of narcissistic tendency and involvement was examined. As a result of study, First, in the relationship between photography and satisfaction, the group who took a photo but did not take a self-shot showed higher satisfaction than the group who did not take a photo and self-shot in the exhibition area. This result shows that photographing the art work in the exhibition hall gives experience-based satisfaction to the visitors, but self-shot does not show positive effect on the satisfaction. Second, the hypothesis that the flow degree will play a mediating role of the visitor's experience-based satisfaction in the relationship between art work photo-shot and self-shot type in exhibition hall was rejected. Third, the positive effect of involvement was shown only in the groups that did not take self-shot but took pictures in the exhibition hall. This shows that the satisfaction of the self-shot visitor is not affected by the degree of involvement of art. The results of this study are expected to help determine the policy for permission to take photographs in art galleries.

• Korean Journal of Remote Sensing
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• v.28 no.4
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• pp.459-466
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• 2012

Satellite operation is divided as user's request, image collection planning, product generation, distribution. Image collection planning is to make image collection plan of satellite to reflect user's request in proper time based on NTO (New Task Order) and AO (Archive Order) using limited satellite resources. Image collection planning has high computational cost because of considering several variables simultaneously, is to be performed identical process repeatedly. In this paper, optimization research of image collection planning is performed for efficient planning. First, formulation of image collection planning is made to require satellite image as much as possible and then Heuristic algorithm is suggested for solution of formulation.