• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.2
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• pp.49-64
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• 2008

Recently, many researches about making more comfortable input device based on gaze detection technology have been done in human computer interface. However, the system cost becomes high due to the complicated hardware and there is difficulty to use the gaze detection system due to the complicated user calibration procedure. In this paper, we propose a new gaze detection method based on the 2D analysis and a simple user calibration. Our method used a small USB (Universal Serial Bus) camera attached on a HMD (Head-Mounted Display), hot-mirror and IR (Infra-Red) light illuminator. Because the HMD is moved according to user's facial movement, we can implement the gaze detection system of which performance is not affected by facial movement. In addition, we apply our gaze detection system to 3D first person shooting game. From that, the gaze direction of game character is controlled by our gaze detection method and it can target the enemy character and shoot, which can increase the immersion and interest of game. Experimental results showed that the game and gaze detection system could be operated at real-time speed in one desktop computer and we could obtain the gaze detection accuracy of 0.88 degrees. In addition, we could know our gaze detection technology could replace the conventional mouse in the 3D first person shooting game.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.307-313
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• 2022

As the development of renewable energy expands internationally to cope with global warming and climate change, the share of wind power generation has been gradually increasing. Although wind farms can produce electric power for 24 h a day compared to solar power plants, Their interfere with the operation of nearby radars or communication equipment must be analyzed because large-scale wind power turbines are installed. This study analyzed whether a land radio station can receive sufficient signals when a ship sailing outside the offshore wind farm transmits distress signals on the VHF band. Based on the geographic information system digital map around the target area, wind turbine CAD model, and wind farm layout, the area of interest and wind farm were modeled to enable numerical analysis. Among the high frequency analysis techniques suitable for radio wave analysis in a wide area, a dedicated program applying physical optics (PO) and shooting and bouncing ray (SBR) techniques were used. Consequently, the land radio station could receive the electromagnetic field above the threshold of the VHF receiver when a ship outside the offshore wind farm transmitted a distress communication signal. When the line of sight between the ships and the land station are completely blocked, the strength of the received field decreases, but it is still above the threshold. Hence, although a wind farm is a huge complex, a land station can receive the electromagnetic field from the ship's VHF transmitter because the wave length of the VHF band is sufficiently long to have effects such as diffraction or reflection.

• The KIPS Transactions:PartB
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• v.14B no.5
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• pp.329-336
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• 2007

In this paper we propose both the construction of image DB including information on the shooting location and direction of the captured outdoor images and the efficient retrieval method from the DB. Furthermore, for the automatic extraction of the location and direction information, we suggest to have the Digital Camera equipped with an expandable GPS modulo which has a function to calculate the location and direction and also to utilize GPS IFD tags in the EXIF. Then that will make it possible for us to retrieve quickly and precisely the target image with its geography and other objects on the ground included. In the previous retrieval method based only on the location, we eel some extra useless images due to the fact that all the images in the ROI(Region Of Interest) are searched on one condition, radius. However, with the proposed method in this paper, we can not only retrieve all the images selectively within the ROI but also achieve nearly 100% of precision when we search for the target images within DOI(Direction Of Interest) with another condition, direction, added. Applying this method to an image retrieval system, we can classify or retrieve natural images based on the location and direction information, which, in turn, will be vitally useful to diverse industrial fields such as disaster alarm system, fire and disaster prevention system, traffic information system, and so forth.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.40 no.2
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• pp.69-77
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• 2022

The 3D spatial model is an analysis framework for solving urban problems and is used in various fields such as urban planning, environment, land and housing management, and disaster simulation. The utilization of drones that can capture 3D images in a short time at a low cost is increasing for the construction of 3D spatial model. In terms of building a virtual city and utilizing simulation modules, high location accuracy of aerial survey and precision of 3D spatial model function as important factors, so a method to increase the accuracy has been proposed. This study analyzed location accuracy of aerial survey and precision of 3D spatial model by each condition of aerial survey for urban areas where buildings are densely located. We selected Daerim 2-dong, Yeongdeungpo-gu, Seoul as a target area and applied shooting angle, shooting altitude, and overlap rate as conditions for the aerial survey. In this study, we calculated the location accuracy of aerial survey by analyzing the difference between an actual survey value of CPs and a predicted value of 3D spatial Model. Also, We calculated the precision of 3D spatial Model by analyzing the difference between the position of Point cloud and the 3D spatial Model (3D Mesh). As a result of this study, the location accuracy tended to be high at a relatively high rate of overlap, but the higher the rate of overlap, the lower the precision of 3D spatial model and the higher the shooting angle, the higher precision. Also, there was no significant relationship with precision. In terms of baseline-height ratio, the precision tended to be improved as the baseline-height ratio increased.

• 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.

• Korean Journal of Optics and Photonics
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• v.1 no.1
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• pp.46-51
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• 1990

Laser plasma was generated by a 1GW iodine photodissociation laser ($\lambda$=1.315$\mu\textrm{m}$, E=12.7J) whose output beam was focused on a molybdenum target surface. The experiment was conducted in a vacuum chamber under 1D-sTorr and several tens of laser shooting were necessary for sufficient exposure for the PBS resist of 111m thickness. Aluminium was coated on the top of the resist by 0.1$\mu\textrm{m}$ thickness which acts as an X-ray filter to cut off the visible and the ultraviolet lights. A bio-specimen was put directly on the aluminium coated resist and located at a distance of 3 cm from the X-ray source. The replicas of a steel mesh, spider's web. and a red blood cell were obtained by this technique and were observed by Nomarski microscope and SEM. The limitation of its resolution is determined by the X-ray source size and Fresnel diffraction effect, and its theoretical prediction is well matched with the experimental results. In this experiment, a resolution better than 0.1$\mu\textrm{m}$ could be obtained. ained.

• Design & Manufacturing
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• v.16 no.2
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• pp.33-38
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• 2022

Currently, Korea is an aging society, and it is expected to enter a super-aging society in about 4 years. Accordingly, many X-ray technologies are being developed. In X-rays, 99% of X-rays are converted into heat energy and 1% into light energy (X-rays). 99% of the thermal energy raises the temperature of the anode and its surroundings, and the cooling system is an important factor as overheating can affect the deterioration of X-ray quality and shortened lifespan. There is a method of forced air cooling using natural convection. Therefore, in this study, when X-rays were taken 5 times, Flow analysis was performed on heat removal according to temperature rise and cooling time for the heat generated at the anode of the X-ray tube (input power 60kW, 75kW, 90kW). Based on one-shot, the most rapid temperature rise section increased by more than 57% to 0.03 seconds, A constant temperature rises from 0.03 seconds to 0.1 seconds, It is judged that the temperature rises by about 8.2% or more at one time. After one-shot cooling, the cooling drops sharply from about 60% to 0.03 seconds, It is judged that the temperature has cooled by more than 86% compared to the temperature before shooting. One-shot is cooled by more than 86% with cooling time after 0.1 seconds, As the input power of the anode increases, the cooling temperature gradually increases. Since the tungsten of the anode target inside the X-ray tube may be damaged by thermal shock caused by a rapid temperature rise, an improvement method for removing thermal energy is required when using a high-input power supply.

• Korean Journal of Remote Sensing
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• v.34 no.6_1
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• pp.905-923
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• 2018

In order to generate high-resolution products using UAV images, it is necessary to analyze the sharpness of the themselves measured through image analysis. When images that have unclear sharpness of UAV are used in the production, they can have a great influence on operations such as acquisition and mapping of accurate three-dimensional information using UAV. GRD (Ground Resolved Distance) has been used as an indicator of image clarity. GRD is defined as the minimum distance between two identifiable objects in an image and is used as a concept against the GSD (Ground Sampling Distance), which is a spatial sample interval. In this study, GRD is extracted by analyzing the edge target without visual analysis. In particular, GRD to GSD ratio (GRD/GSD), or GRD expressed in pixels, is used as an index for evaluation the relative image sharpness. In this paper, GRD is calculated by analyzing edge targets at various altitudes in various shooting environments using a rotary wing. Using GRD/GSD, it was possible to identify images whose sharpness was significantly lowered, and the appropriateness of the image as an image clarity index was confirmed.

• Korean Security Journal
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• no.18
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• pp.73-99
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• 2009

There are three assassination and treatening cases in this thesis introduced as analysis data. They are shooting accidents of the U.S.A's President Reagun (1981,3.30), and the President Park Jeong Hee of South Korea(1974.8.15), assassination of the Prime Minister Lavin of Israel (1995.11.4) In March 30, 1981, there was an accident where criminal, Hinckley, fired ball cartridges right before the President Reagan got into the car to move to White House after completing the announcement of Hilton Hotel of Washington. As a result, the chest of president was shot and public information secretary and safeguard were wounded. In August, 15, pm 10:23, where the 29th 8.15 independent anniversay event was being celebrated by the people at the National theater in Jangchungdong, Seoul, the criminal Moon Sekwang fired ball cartridges, he failed to assassinate the President Park Jeong Hee of Korea, but shot the First lady Yuk Young Soo. She was wounded right part of head and died. In November 4, Saturday, pm 22:00 the Prime Minster Lavin had finished the supporting event of Middle Asia's Peace project and was taking on the car when he was killed by the criminal Amir's shooting, The accidents left very important lesson from the aspect of security analysis and it has been frequently used as a material for the education and training of safeguard organization. In Korea, as well as Presidential Security Service, national security departments have selected it as an important model for the subjects such as 'Security Analysis, 'Security Practice' and 'Security Methodology'. In the performance of security duty, security skill is the most important matter. Moreover, it has a close relationship with politics, society and culture. The purpose of this study is to analyze and reevaluate the case, which has been treated as a usual model from the aspect of security analysis, beyond its introduction. Attempted assassination of President Reagan was evaluated as a positive success example because of its rapid response of adjacent guards to evacuate Reagan, who is a guard target, within 10 seconds after the shot. When comparing it to President Kennedy Assassination of 1963, it was evaluated that guards were significantly specialized. In the study, however, it was possible to found many problems such as carelessness of guard, who is in charge of external area of event place, idle attitude for frequently used event place, confusion of wireless communication, risk of wireless security disclose, insufficient provision of compulsory record file, insufficient profiling of dangerous person and unsecured hospital and first-aid room.

• Journal of Soil and Groundwater Environment
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• v.14 no.1
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• pp.51-60
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• 2009

A series of experiments was performed to develop an optimized analytical procedure for the analysis of explosives in soil by HPLC with soil samples collected at two live-fire military shooting ranges. The minimum amount of soil to be collected, Wmin, for the analysis of explosive compounds was 125g, based on the segregation and homogeneity constants that account for soil heterogeneity and non-homogeneous distribution of target explosive compounds. The optimization of extraction and HPLC analytical conditions were also studied based on analytes CV values. The most effective soil/ extractant ratio was estimated to be 10g-pretreated soil/20 mL acetonitrile as extractant. The optimized HPLC elution conditions for the separation of US EPA designated 14 explosive compounds, were column temperature 30${\circ}C$, eluents ratio of isopropanol: acetonitrile: water = 18 : 12: 70, and flow rate of 0.8 mUmin at 230 nm. However, UV wavelength 254 nm was better for the analysis of NB, 2,4-DNT, 2NT, 4NT, and 3NT.