• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.167-174
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• 2009

A Tile Map Service is a regular map service that has been enhanced to serve maps very quickly using a cache of static images. The map cache is a directory that contains image tiles of a map extent at specific scale levels. Returning a tile from the cache takes the server much less time than drawing the map image on demand. Use of a Tile Map Service can dramatically improve the time that clients take to display complex base-maps. Using Tile Map Services thus eliminate the need to trade quality for performance. This study provides a way to construct Tile Map Service System using Open Source GIS. We used GDAL(Geospatial Data Abstraction Library) which is one of the Open Source GIS Softwares to make Tile Map Image and OpenLayers to publish Web Page. Moreover, We conducted a performance test on Tile Map System and Dynamic Map System and evaluated the results of it. As a result, the proposed method makes it easier to construct high performance Tile Map Service using Open Source GIS without commercial products.

• Journal of Digital Contents Society
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• v.15 no.6
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• pp.751-761
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• 2014

Color deficient people do not have sufficient discernment for the colors with low saturation and brightness and at the same time express their negative emotions regarding emotion distortion. The purpose of recovering the distortion of the vision which is the basis for emotion is to increase positive emotions rather than negative ones that those with color vision deficiency feel when they experience digital culture contents. Contrast increases saturation and brightness by differing the direction of their conversion and by doing so, delivers emotion distortion such as dynamic vs. static and vivid vs. somber that the original images intend to convey to those with color vision deficiency by reducing such a contrast. In this respect, this study proposes a contrast-based color conversion method to convert saturation and brightness in the zone of color conversion and identifies if this method can reduce emotion distortion by using color conversion simulation and user test.

• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.11-19
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• 2013

For an autonomous multi-mobile robot system, path planning and collision avoidance are important functions used to perform a given task collaboratively and cooperatively. This study considers these important and challenging problems. The proposed approach is based on a potential field method and fuzzy logic system. First, a global path planner selects the paths of the robots that minimize the cost function from each robot to its own target using a potential field. Then, a local path planner modifies the path and orientation from the global planner to avoid collisions with static and dynamic obstacles using a fuzzy logic system. In this paper, each robot independently selects its destination and considers other robots as dynamic obstacles, and there is no need to predict the motion of obstacles. This process continues until the corresponding target of each robot is found. To test this method, an autonomous multi-mobile robot simulator (AMMRS) is developed, and both simulation-based and experimental results are given. The results show that the path planning and collision avoidance strategies are effective and useful for multi-mobile robot systems.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.11
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• pp.953-960
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• 2021

Korea Astronomy and Space Science Institute has been verifying the multipurpose laser tracking system with three functions of satellite laser tracking, adaptive optics and space debris laser tracking for not only scientific research but also national space missions. The system employs an optical telescope consisting of a 100 cm primary mirror and an altazimuth mount for fast and precise tracking. The precise pointing and tracking capability in a tracking mount is considered as one of important performance metrics in the fields of automatic tracking and precise application research. So it is required to analyze a mount model for investigating pointing error factors and compensating pointing error. In this study, we investigated various factors causing static pointing errors of tracking mount and analyzed the pointing accuracy of the tracking mount at Geochang observatory by estimating mount parameters based on the least square method.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.283-288
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• 2019

We propose a method to search for similar images by using outline lines and viewpoints. In the first test, the three-dimensional image, which can't control the motion, has lower search accuracy than the static flat image. For the cause analysis, six specific tropical fish data were selected. We made a 3D graphics of tropical fishes of each kind, and we made 144 image outline lines with 12 stage viewpoints of top, bottom, left and right. Tropical fish by type were collected and sorted by time of search through similar search. Studies have shown that there are many unique viewpoints for each species of tropical fish. To increase the accuracy of the search, a User Interface was created to select the user's point of view. When the user selects the viewpoint of the image, a method of showing the result in consideration of the range of the related viewpoint is proposed.

• Journal of the Korea Convergence Society
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• v.12 no.3
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• pp.371-379
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• 2021

This study aimed to verify the mediating effect of rejection sensitivity on the relationship between self-esteem and happiness among nursing students. From May 30 to June 10, 2018, 214 nursing students from a university were selected for convenience, and the results were analyzed using SPSS 22.0. The degree to which the rejection sensitivity of nursing students is mediated by self-esteem and happiness was determined following the guidelines of Baron and Kenny, and the Sobel test was used to verify the statistical significance of the mediated effects. There was a positive correlation between self-esteem and happiness among nursing students(r=.62, p<.001) and a negative correlation between rejection sensitivity and happiness(r=-.33, p<.001). A partially mediated effect (Z=3.769, p<.001) of rejection sensitivity was found on the relationship between self-esteem and happiness of nursing students. Therefore, education and activity programs are needed to increase the happiness of nursing students and help them maintain a satisfactory college life.

• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.39-46
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• 2023

We present an efficient packet transmission strategy for massively multiplayer online first-person shooter (MMOFPS) games using movement-adaptive packet transmission interval. The player motion in FPS games shows a wide spectrum of movement variability both in speed and orientation, where there is room for reducing the number of packets to be transmitted to the server depending on the predictability of the character's movement. In this work, the degree of variability (nonlinearity) of the player movements is measured at every packet transmission to calculate the next transmission time, which implements the adaptive transmission frequency according to the amount of movement change. Server-side prediction with a few auxiliary heuristics is performed in concert with the incoming packets to ensure reliability for synchronizing the connected clients. The comparison of our method with the previous fixed-interval transmission scheme is presented by demonstrating them using a test game environment.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.4
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• pp.107-113
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• 2023

This paper proposes a method for detecting smoking behavior in images using artificial intelligence technology. Since smoking is not a static phenomenon but an action, the object detection technology was combined with the posture estimation technology that can detect the action. A smoker detection learning model was developed to detect smokers in images, and the characteristics of smoking behaviors were applied to posture estimation technology to detect smoking behaviors in images. YOLOv8 was used for object detection, and OpenPose was used for posture estimation. In addition, when smokers and non-smokers are included in the image, a method of separating only people was applied. The proposed method was implemented using Google Colab NVIDEA Tesla T4 GPU in Python, and it was found that the smoking behavior was perfectly detected in the given video as a result of the test.

• The Journal of Engineering Geology
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• v.28 no.3
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• pp.465-473
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• 2018

The application of singular value decomposition (SVD) filtering is examined for attenuation of the ground-roll in land seismic data. Prior to the SVD computation to seek singular values containing the highly correlatable reflection energy, processing steps such as automatic gain control, elevation and refraction statics, NMO correction, and residual statics are performed to enhance the horizontal correlationships and continuities of reflections. Optimal parameters of SVD filtering are effectively chosen with diagnostic display of inverse NMO (INMO) corrected CSP (common shot point) gather. On the field data with dispersion of ground-roll overwhelmed, continuities of reflection events are much improved by SVD filtering than f-k filtering by eliminating the ground-roll with preserving the low-frequency reflections. This is well explained in the average amplitude spectra of the f-k and SVD filtered data. The reflectors including horizontal layer of the reservoir are much clearer on the stack section, with laminated events by SVD filtering and subsequent processing steps of spiking deconvolution and time-variant spectral whitening.

• Journal of the Korean Geographical Society
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• v.42 no.5
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• pp.710-727
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• 2007

This paper suggests an inquiry into the characteristics and implications of urbanscapes produced by Internet cafes, widely called PC Bangs in Korea, and their effects on the motions and boundaries of human bodies as cyborgs which exist in between actual and virtual spaces or between human and machine spaces in PC Bangs. The paper, which is organised into two main sections, first investigates the streetscapes of PC Bangs as electronic architectural spaces and suggests the urban electronic space of PC Bangs in terms of hypertext space. Then, it looks at the effects of PC Bangs on human bodies which exist as human-machine hybrids or cyborgs in PC Bangs. The paradoxical socio-spatial characteristics of PC Bangs as third, liminal or hybrid spaces between actual and virtual spaces or between human and machine spaces can be explained as follows. Firstly, there appear both nomadic and sedentary landscapes in that people in PC Bangs move in virtual spaces on the one hand, and are static in actual spaces on the other hand. Secondly, both open and closed spaces are shaped in that although PC Bangs act as open or public electronic spaces, they involve invisible social boundaries, forming the gendered space of masculinism. Thirdly, the boundaries of the human body are extended and are shrunk at the same time in that while the sensory boundaries of the body in PC Bangs are extended through electronic networks, its social boundaries are shrunk through the imaginary space of solipsism. Thus and finally, PC Bangs can be characterised not only as social spaces entailing embodied and gendered landscapes, but also as non-places involving the cyborg landscapes of human-machine connections.