• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.2
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• pp.139-149
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• 2012

Flooding caused by torrential rains and landslide causes the deaths of people and property damage as well as traffic congestion and isolation. Driver enters the dangerous area when driver doesn't recognize disaster information on the road and the damage is spread over time. In this paper, we will develop a smart phone application to collect dangerous disaster area information and a system based on C/S to manage the data received from the smart phone application. This system can analyze dangerous disaster areas using the data received from the smart phone application and the spatial database analyzed dangerous disaster areas is displayed in the smart phone application using a map server. We think that the suggested system provides more efficient information to user.

• Journal of the Korea Computer Graphics Society
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• v.22 no.3
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• pp.89-99
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• 2016

One of the fundamental elements in developing mixed reality applications is to effectively analyze and apply the environmental lighting information to image synthesis. In particular, interactive applications require to process dynamically varying lighting sources in real-time, reflecting them properly in rendering results. Previous related works are not often appropriate for this because they are usually designed to synthesize photorealistic images, generating too many, often exponentially increasing, light sources or having too heavy a computational complexity. In this paper, we present a fast light source estimation technique that aims to search for primary light sources on the fly from a sequence of video images taken by a camera equipped with a fisheye lens. In contrast to previous methods, our technique can adust the number of found light sources approximately to the size that a user specifies. Thus, it can be effectively used in Phong-illumination-model-based direct illumination or soft shadow generation through light sampling over area lights.

• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.4
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• pp.143-154
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• 2005

This paper proposes the location acquisition methods and LBS(location-based services) system using RFID(radio frequency identification) tags with location information in ubiquitous city. Location information is checked using RFID tags attached to various buildings. stores and road signs. And various LBSs are provided based on the location information. Traditionally, when the location information is obtained by a GPS, the precision of the location information may deteriorate due to geographical displacement of a satellite and GPS receivers, for example shadow zone by building, in-door environment, and heavy cloud. The objective of this paper is to provide a ULID(universal location identification) data structure, a ULID-based location acquisition method and an LBS system, in which precise location information is extracted using RFID tags attached to various buildings, stores and road signs and ULID and also danger of information leakage is minimized so that an LBS of ubiquitous environment can be provided to a user.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.463-470
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• 2017

Currently, virtual reality contents using VR images are spotlighted since they can be easily created and utilized. But because VR images are in a state of lack of interaction, there are limitations in their applications and usability.In order to overcome this problem, we propose a new method in which 360 degree panorama image and game engine are utilized to develop a high resolution of interactive VR service in real time. In particular, since the background image, which is represented by a form of panorama image, is pre-generated through a heavy rendering computation, it can be used to provide a immersive VR service with a relatively small amount of computation in run time on a low performance device. In order to show the effectiveness of our proposed method, an interactive game of a virtual zoo environment was implemented and illustrated showing that it can improve user interaction and immersion experience in a pretty good way.

• Journal of KIISE
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• v.43 no.12
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• pp.1356-1364
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• 2016

This paper proposes a novel aesthetic photo recomposition method using a deep convolutional neural network (DCNN). Previous recomposition approaches define the aesthetic score of photo composition based on the distribution of salient objects, and enhance the photo composition by maximizing the score. These methods suffer from heavy computational overheads, and often fail to enhance the composition because their optimization depends on the performance of existing salient object detection algorithms. Unlike previous approaches, we address the photo recomposition problem by utilizing DCNN, which shows remarkable performance in object detection and recognition. DCNN is used to iteratively predict cropping directions for a given photo, thus generating an aesthetically enhanced photo in terms of composition. Experimental results and user study show that the proposed framework can automatically crop the photo to follow specific composition guidelines, such as the rule of thirds.

• Archives of design research
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• v.20 no.3 s.71
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• pp.289-298
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• 2007

The EGI system is a new communication method in limelight for helping disabled users to input and handle information on the computer more easily. However, due to the EGI system's "JEM(Jittery Eye Movements)" generation, it actually increases heavy psychological and physiological stresses for the user to input or perceive the target information on a machine. This study illustrates how to resolve this "JEM" issue and suggests a method that is easy and simple to be controled by anyone. A demo tool was built and tested to find and prove the reasons for "JEM" This test shows that that the case with snap up is less stressful than without to input text as a final result of the test evaluation in both psychological snap up and physiological brain wave test. Postnatal or naturally acquired, it is found that the disabled can have opportunities for smoother communication, and a possible efficient system development for better communication.

• The Journal of Information Systems
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• v.19 no.3
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• pp.209-236
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• 2010

Recently, utilization of mobile Internet services is rapidly increasing. To properly accelerate the vitalization of mobile Internet usage, we have to know exactly about the factors affecting potential users' value recognition and intention to use. Technology acceptance model (TAM) is one of the most powerful reference framework for the individual user's adoption of IT innovations. This research borrowed core concept of TAM, and tried to explain users' intention to use mobile Internet by understanding the direct and indirect effects of subjective norm and perceived usefulness. To increase the explanatory power of the model, this paper introduced personal innovativeness as a key moderator variable. The research findings include; i) subjective norm has strong positive influence on perceived usefulness and intention to use, ii) perceived usefulness has positive influence on intention to use, iii) the influence of subject norm is greater than that of perceived usefulness, iv) positive influence of subjective norm on the perceived usefulness and intention to use are significantly stronger in the case of low personal innovativeness sub-group than the case of high personal innovativeness sub-group, and v) high personal innovativeness sub-group have shown strongly positive influence of perceived usefulness on the intention to use while there is no such significant relationship in the case of low personal innovativeness sub-group. Based on these findings, this paper proposed several guidelines to increase the adoption and the usage of mobile Internet; i) word-of-mouth is extremely important, ii) to form a good word-of-mouth, it will be very important to make early adopters and heavy users have positive direct experiences of using mobile Internet.

• Journal of Korea Game Society
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• v.11 no.4
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• pp.151-162
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• 2011

The purposes of this study were to find out the effect of children's and adolescents' achievement through the online game on their self-efficacy, school adjustment and life satisfaction in accordance with the degree of their online game playing. In heavy user group, children's and adolescents' achievement through the internet game had positive effect on their self-efficacy, school adjustment and life satisfaction. Also their self-efficacy mediated the relationship between their achievement through the online game and school adjustment, achievement through the online game and life satisfaction. This study investigated the fact that children's and adolescents' achievement through the online game affects their real life and found out positive possibility of the online game.

• Journal of Korea Multimedia Society
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• v.14 no.7
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• pp.933-939
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• 2011

Recent heavy rains have caused natural disasters such as flooding and landslides nationwide. Because of flooding occurrence in most of the roads, traffic congestion and isolation caused many loss especially at rush hour. Constant monitoring and analysis of past disaster history data are needed to prevent disasters on areas prone to floods and disaster risk areas. If we managed to obtain traffic volume, speed, phase around intersection using disaster history data when disasters occurred, we can analyse traffic congestion, change of disaster scale and rainfall. In this study, We select a target district to develop by using a route from Dae-nam intersection in Busan Namgu Daeyoeon-dong, over Gwangan large bridge up until Haeundae Olympic intersection, We developed a system which searches disaster history information, traffic volume using disaster history data based on user selection of the road.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.6
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• pp.339-347
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• 2010

Inter-process communication (IPC), which is a technique that enables exchanging data among multiple processes, is commonly used not only in user applications but also in system processes. For this reason, the performance of IPC highly influences the performance of whole computer system. Especially, heavy overload on a single server process caused by IPC requests from multiple client processes, easily results overall slowdown of IPC response time. Here, to deal with the problem stated above, the time-slice donation technique which is adapted in L4 microkernel is analyzed and enhanced for reducing latency of IPC response time and implemented on linux kernel for actual performance evaluation. While trying to maintain the additional overhead as least as possible, the experiment shows that the use of this technique enhances the performance of IPC multiple times of existing technique under certain circumstances.