• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.123-127
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• 2020

In order to obtain the overall fire line information of medium and large forest fires at night, the ground control system was developed to determine whether forest fires occurred through real-time video clips and to calculate the location of the forest fires determined using the location of drones, angle information of video cameras, and altitude information on the map to reduce the time required for regular video matches obtained after the completion of the mission. To verify the reliability of the developed function, the error distance of the aiming position information of the flight altitude star and the image camera was measured, and the location information within the reliable range was displayed on the map. As the function developed in this paper allows real-time identification of multiple locations of forest fires, it is expected that overall fire line information for the establishment of forest fire extinguishing measures will be obtained more quickly.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.105-115
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• 2017

Conventional traffic detection sensors such as loop detectors and image sensors are expensive to install and maintain and require different detection algorithms depending on the night and day and have a disadvantage that the detection rate varies widely depending on the weather. On the other hand, the millimeter-wave radar is not affected by bad weather and can obtain constant detection performance regardless of day or night. In addition, there is no need for blocking trafficl for installation and maintenance, and multiple vehicles can be detected at the same time. In this study, a multi-target detection algorithm for a radar sensor with this advantage was devised / implemented by applying a conventional single target detection algorithm. We performed the evaluation and the meaningful results were obtained.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.5
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• pp.41-51
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• 2014

The purpose of this study is to understand the relationship between physical characteristics and general people's perception. In this study, the physical quantities of artificial lighting were measured from the visual point of the pedestrian and general public perception including preference and satisfaction was examined. As a result of this study, the total luminance and mean luminance had different value in each site. However, there were no significant differences in area and number of light source between sites. The effects of these factors are affected by indoor lighting. In the group of respondents, 10s people, male, students, meeting, 1~2 times a month and 18:00~20:00 had higher satisfaction compared to other groups respectively. A total luminance and mean luminance gave effect on the satisfaction of physical quantities of artificial lighting and the satisfaction on night landscape. With increase in total luminance and mean luminance, the satisfaction was lowered. It is necessary to reflect these factors on the future policies of nightscape.

• 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 Korean Astronomical Society
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• v.54 no.4
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• pp.113-119
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• 2021

It is difficult for observers to conduct an optical alignment at an observatory without the assistance of an optical engineer if optomechanical parts are to be replaced at night. We present a practical tilt correction method to obtain the optimal optical alignment condition using the symmetricity of optical aberrations of a wide-field on-axis telescope at night. We conducted coarse tilt correction by visually examining the symmetry of two representative star shapes obtained at two guide chips facing each other, such as east-west or north-south pairs. After coarse correction, we observed four sets of small stamp images using four guide cameras located at each cardinal position by changing the focus positions in 10-㎛ increments and passing through the optimum focus position in the range of ±200 ㎛. The standard deviation of each image, as a function of the focus position, was fitted with a second-order polynomial function to derive the optimal focus position at each cardinal edge. We derived the tilt angles from the slopes converted by the distance and the focus position difference between two paired guide chip combinations such as east-west and north-south. We used this method to collimate the on-axis wide-field telescope KMTNet in Chile after replacing two old focus actuators. The total optical alignment time was less than 30 min. Our method is practical and straightforward for maintaining the optical performance of wide-field telescopes such as KMTNet.

• Nutrition Research and Practice
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• v.18 no.4
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• pp.523-533
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• 2024

BACKGROUND/OBJECTIVES: Given that adolescents watch Mukbang (eating broadcast) more frequently than other age groups, interest in the potential health effects of watching Mukbang and Cookbang (cooking broadcast) is growing. This study aimed to determine the status of watching Mukbang and Cookbang among Korean adolescents and its relationship with their dietary behaviors. SUBJECTS/METHODS: We used data from the 18th Korea Youth Risk Behavior Survey, conducted in 2022 (n = 51,850). The study included the frequency of watching Mukbang and Cookbang and the self-rated impact of watching them. Dietary behaviors included consumption of the following items: fruits (≥ once a day), vegetables (≥ 3 times a day), fast foods (≥ 3 times a week), late-night snacks (≥ 3 times a week), caffeinated drinks (≥ 3 times a week), and sweet-flavored drinks (≥ 3 times a week). Furthermore, obesity, weight loss attempts during the past 30 days, body image distortion, and inappropriate methods to control weight were also included. RESULTS: Among adolescents, 70.6% watched Mukbang and Cookbang, and 13.2% watched them more than 5 times a week. Approximately 27.6% of the adolescents responded that they were influenced by watching Mukbang and Cookbang. Adolescents who frequently watched Mukbang and Cookbang consumed less vegetable and fruit; however, the likelihood of consuming fast food, late-night snacks, sugary drinks, and caffeinated drinks increased. In addition, they were more likely to attempt inappropriate weight-loss methods and become obese. Adolescents who responded that their eating habits were influenced by watching Mukbang and Cookbang were more likely to have unhealthy eating behavior compared to the group who responded that their habits were not influenced by these shows. CONCLUSION: Watching Mukbang and Cookbang is common among Korean adolescents and is associated with unhealthy dietary behaviors. Prospective studies, including broadcasting content, should evaluate the impact of Mukbang and Cookbang on health.

• Korean Journal of Optics and Photonics
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• v.35 no.5
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• pp.228-234
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• 2024

Modern infrared-guided weapons detect and destroy targets by seeking and tracking the infrared radiation emitted by the target. By covering the target with a material that has low infrared emissivity, the infrared signal can be reduced to evade tracking. However, this method is effective only when the target is hotter than the background. Since the temperature of the background varies significantly between day and night, target signals with low emissivity at night can be captured by the optical systems of guided weapons due to signal contrast, as they are smaller than the background signals. In this study, the optimal emissivity for implementing infrared stealth for ground targets is calculated based on the temperature and emissivity of the background, as well as the temperature of the target. The size of the signal received by the optical systems of guided weapons, the contrast value of the image, and the lock-on range were calculated for target signals that vary depending on the emissivity of the target. The effectiveness of the optimal emissivity was demonstrated by thermal imaging computer simulations using COMSOL Multiphysics software.

• Journal of Korean Ophthalmic Optics Society
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• v.19 no.4
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• pp.479-485
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• 2014

Purpose: This study relates to the development of the prism dot-sight combined with the thermal imaging camera. Methods: We have placed a reflector designed to the doublet type in the front of a BS (beam splitting) prism, have placed an OLED panel and a dot reticle generator to the top and bottom of the reflecting surface of the BS prism, and have placed a detachable magnifier between the BS prism and the observer by which the observer can see the magnified image of the OLED panel. By doing this, we were able to configure the new type prism dot-sight combined with the thermal imaging camera. Results: By placing the removable magnifier designed with a new type between the BS prism and the observer, we could design the new type prism dot-sight which performs the role of the dot sight by removing the magnifier during the day-time, and performs the role of the night scope during the night-time by which we can observe the enlarged image of the thermal imaging camera through the BS prism by attaching the removable magnifier. Conclusions: In this study, we have developed the prism dot-sight combined with the thermal imaging camera which is able to play the role of the day or night scope selectively, by disposing the designed magnifier characterized by the focal length of 44 mm, the viewing angle of ${\pm}7.0^{\circ}$, and the MTF value of 0.5 or more at the criterion of 50 lp/mm and the 0.7 field between the BS prism and the observer. By doing so, we could design and fabricate the new type prism dot-sight combined with the thermal imaging camera which can further increase the rapidity of firing and provide more convenience in the mounting of a firearm than the detachable combination of an existing dot sight and an existing night scope.

• Journal of Satellite, Information and Communications
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• v.4 no.2
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• pp.12-19
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• 2009

In the modern UAV systems, the role of radar payload has been increasing with its unique performance of day-and-night operation and see-through capability over hidden obstacles. Contrary to the satellite reconnaissance, UAV is expected to provide high resolution target detection and recognition capability while frequent flight missions would deliver enhanced SAR image and local information over the target area. STK(Satellite Tool Kit) is a professional space-analysis software widely used in all phases of a space system's life cycle. The simulation of STK is efficient and accurate relatively. In this paper, the author attempt to model the UAV operation and measure the expected SAR image quality. STK(Satellite Tool Kit) is employed to analyze UAV operation and produce SAR raw data. A SAR simulator is developed to produce high resolution SAR image for various ground targets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.9
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• pp.757-762
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• 2012

In general, an ordinary CCTV camera has equipped with 24 frames per second. This camera is not capable of capturing an image of bullet trace which has speed about 1km per second. In spite of these difficulties, by means of the stereographical projection, a long distance trace is able to be contained in one image. Currently, to capture a series of image of an object with high speed, it is usual to use one of the complicated camera with high shutter speed or computerized devices with capability of controlling shutter timing with slightly different capture time. This paper proposed a monitoring tracer bullet single camera system equipped convex mirror trying to see whether or not a normal set of camera and convex mirror is capable of shooting on target located in as far as 250m.