• Journal of the Korean Data and Information Science Society
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• v.21 no.5
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• pp.935-944
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• 2010

In this paper, we develop the noninformative priors for the reliability in a stress-strength model where a strength X and a stress Y have independent exponential distributions with different scale parameters and a common location parameter. We derive the reference priors and prove the propriety of joint posterior distribution under the general prior including the reference priors. Through the simulation study, we show that the proposed reference priors match the target coverage probabilities in a frequentist sense.

• Communications for Statistical Applications and Methods
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• v.12 no.3
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• pp.643-652
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• 2005

It has been known that the exponentiated exponential distribution can be used as a possible alternative to the gamma distribution or the Weibull distribution in many situations. But the maximum likelihood method does not admit explicit solutions when the sample is multiply censored. So we derive the approximate maximum likelihood estimators for the location and scale parameters in the exponentiated exponential distribution that are explicit function of order statistics. We also compare the proposed estimators in the sense of the mean squared error for various censored samples.

• Journal of Multimedia Information System
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• v.8 no.2
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• pp.111-120
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• 2021

As recent virtual reality technologies provide a more natural three-dimensional interactive environment, users naturally learn to explore space and interact with synthetic objects. The virtual reality researcher develops a technique that realizes realistic sensory feedback to get appropriate feedback to sense input behavior. Although much recent virtual reality research works extensively consider the human factor, it is not easy to adapt to all new virtual environment contents. Among many human factors, distance perception has been treated as very important in virtual environment interaction accuracy. We study the experiential virtual environment with the feature of the virtual object connected with the real object. We divide the three-dimensional interaction, in which distance perception and behavior have a significant influence, into two types (whole-body movement and direct manipulation) and analyze the real and virtual visual distance perception heterogeneity phenomenon. Also, we propose a statistical correction method that can reduce a near-body movement and manipulation error when changing the interaction location and report the experiment results proving its effectiveness.

• Journal of the Korea Society of Computer and Information
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• v.13 no.2
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• pp.135-141
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• 2008

In this paper, we propose colored-hear recognition that distinguishing feature of synesthesia for human sensing by shared vision and specific sense of hearing. We perceived what potential influence of human's structured object recognition by visual analysis through the camera, So we've studied how to make blind persons can feel similar vision of real object. First of all, object boundaries are detected in the image data representing a specific scene. Then, four specific features such as object location in the image focus, feeling of average color, distance information of each object, and object area are extracted from picture. Finally, mapping these features to the audition factors. The audition factors are used to recognize vision for blind persons. Proposed colored-hear transformation for recognition can get fast and detail perception, and can be transmit information for sense at the same time. Thus, we were get a food result when applied this concepts to blind person's case of image recognition.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.291-295
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• 2022

This paper deal with the advanced thchnology of water supply line breakege detection system in singsan green city. the technology apply for construction eco oriented high-tech city to merge residant, industial, tour reasure parts for songsan green city furture direction achivement and response for a life style change of people in the city. Breakege detection system consist of smart prevention seat, pipeline breakege detection sensor, analysis software, server. etc.. Central control unit sent the data to hwa sung city water supply office by WCDMA in SKY. the data are states about water supply pipeline, Location.etc. This system maintain the long term life cycle of water supply plpeline by the prevention the leakege event through ackonwledge information of evnet occurrence locaion. and used to realtime sense method about demage information of the pipeline and prevent to brekege facilities during excavation work.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39C no.6
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• pp.457-465
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• 2014

This paper introduces a test bed for communication protocol schemes of underwater acoustic sensor network, and also shows experimental results obtained from the test bed. As a testing protocol, carrier sense multiple access/collision avoidance (CSMA/CA) is evaluated on underwater acoustic channel. A sensor node is equipped with a DSP control board of ATmega2560 and a commercial underwater modem produced by Benthos. The control board not only manipulates a GPS signal to acquire the information of location and time, but also controls the underwater modem to operate according to the procedure designed for a given testing protocol. Whenever any event takes place such as exchanging control/data packets between underwater modems and acquiring location and timing information, each sensor node reports them through radio frequency (RF) air interface to a central station located on the ground. The four kinds of packets for CSMA/CA, RTS(Request To Send), CTS(Clear to Send), DATA, ACK(Acknowledgement) are designed according to the underwater communication environment and are analyzed through the lake experiment from the point of feasibility of CSMA/CA in underwater acoustic communications.

• Journal of Information Management
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• v.41 no.4
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• pp.41-67
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• 2010

Augmented reality technology was invented for military purposes at the beginning. But the development of wireless and location based technology in 2000s makes AR services reach the age of innovation. Especially, it attracts attention as a media which enriches our perception. There is a potential that it can extend the virtual information in the real world from optical sense to auditory, tactile, and olfactory sense. This study proposed the interactive information service system and method based on AR. To do it, technical background on AR was analyzed and a method to apply the technology was examined. Especially, as a eco service, this study proposed new information service using 2D bar code in a library for user need and convenience in ubiquitous environment. The proposed service system can optimize practical utilization of information resources in virtual and real reality as consolidating analog and digital resources in a library.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.3
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• pp.157-165
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• 2019

Recently, large and small earthquakes have occurred in the Korean peninsula. In this sense, Korea is no longer considered as an earthquake free zone. Especially, it is necessary to respond quickly to earthquake tsunami which may be caused by the influence of neighboring countries with large earthquakes. Since the occurrence of tsunamis can cause great casualties, it is very important to allocate the location of the shelter in case of an earthquake. Although many researches on shelter allocation have been conducted in various ways, but most of them have been analyzed based on administrative district resident data, resulting in a lack of reality. In this study, floating population data were used to reflect reality in case of emergency situations, and genetic algorithm, which produce good results among the heuristic algorithms, was used to select shelter locations. The number of evacuees was used as a objective function of genetic algorithm and the optimal solution was found through selection, crossover and mutation. As a result of the research on Busan Haeundae-Gu, selected as a research area, allocating eight shelters was the most efficient. The location of the new shelters was selected not only in residential areas but also in major tourist areas whose results can not be derived from administrative district resident data alone, and the importance of utilizing the floating population data was confirmed through this study.

• Journal of the Korea Society of Computer and Information
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• v.29 no.3
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• pp.99-106
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• 2024

In this paper, we design and implement the HealthSchedule app, which records exercise data based on the GPS sensor embedded in smartphones. This app utilizes the smartphone's GPS sensor to collect real-time location information of the user and displays the movement path to the designated destination. It records the user's actual path using latitude and longitude coordinates. Users register exercise activities and destination points when scheduling, and initiate the exercise. When measuring the current location, a lime green departure marker is generated, and the movement path is displayed in blue, with the destination marker and a surrounding 25-meter radius circle shown in sky blue. Using the coordinates of the starting point or the previous location and the current GPS sensor-transmitted location coordinates, it measures the distance traveled, time taken, and calculates the speed. Furthermore, it accumulates measurement data to provide information on the total distance traveled, movement path, and overall average speed. Even when reaching the destination during exercise, the movement path continues to accumulate until the completion button is clicked. The completion button is activated when the user moves into the sky blue circular area with a radius of 25 meters, centered around the initially set destination. This means that the user must reach the designated destination, and if they wish to continue exercising without clicking the completion button, they can do so. Depending on the selected exercise type, the app displays the calories burned, aiming to increase user engagement and a sense of accomplishment.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.5
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• pp.382-388
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• 2016

When Flat Panel Display (FPD) is made with backlight module, such as LED TV, it inherently suffers from the non-uniform backlight luminance problem that results in un-even brightness distribution throughout the TV screen. If the luminance of each pixel location of a TV screen as a function of the driving voltage can be measured, it can be used to compensate the non-uniformity of the backlight module. We use a carefully calibrated imaging system to take pictures of a TV screen at different levels of brightness and generate the compensation functions for the driving circuitry to correct the luminance level at each pixel location. Making use of the fact that the luminance of the screen is normally brightest at around the center of the screen and gradually decreases toward the border of the screen, the luminance of the whole TV screen is approximated by a mathematical function of the pixel locations. The parameters of the function are computed in the least square sense by the values of both the pixel luminance sent from the driving circuit and the grayscale value measured from the image taken by the imaging system. To justify the correction system, a simple second order polynomial function is used to approximate the luminance across the screen. When the driving circuit voltage is corrected according to the measured function, the variance of the screen luminance is reduced to one tenth of the one measured from the un-corrected TV screen.