• Journal of KIISE
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• v.41 no.12
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• pp.1110-1116
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• 2014

Nowadays, social networking sites (SNSs), such as Twitter, LinkedIn, and Tumblr, are coming into the forefront, due to the growth in the number of users. While users voluntarily provide their information in SNSs, privacy leakages resulting from the use of SNSs is becoming a problem owing to the evolution of large data processing techniques and the raising awareness of privacy. In order to solve this problem, the studies on protecting privacy on SNSs, based on graph and machine learning, have been conducted. However, examples of privacy leakages resulting from the advent of a new SNS are consistently being uncovered. In this paper, we propose a technique enabling a user to detect privacy leakages beforehand in the case where the service provider or third-party application developer threatens the SNS user's privacy maliciously.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.8
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• pp.455-476
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• 2006

An avatar script language consists of commands set which is used to control avatar behaviors in cyberspace. The script language should be abstract from complex low-level concepts, so that a user can write down a scenario script easily without concerning about physical motion parameters. Also, the script should be defined in a standard format and structure to allow reusing in various implementation tools. In this paper, a layered script language is proposed for avatar behavior representation and control, which consists of task-level behavior, high-level motion and primitive motion script language. The script language of each layer represents behavior elements for a scenario scripting interface, an avatar motion sequence, and geometric information of implementation environment, respectively. Therefore, a user can create a scenario script by abstract behavior interface and a script can be applied to various implementations by the proposed translating process. A presentation domain is chosen for applying the proposed script language and the implementation result shows that the script is flexibly applied in several applications.

• The Journal of Information Systems
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• v.25 no.3
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• pp.61-90
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• 2016

Purpose Recently the usage of Mobile Instant Messenger(MIM) has been increased all over the world. With the development of Mobile Internet, a large amount of mobile application came into being, such as WeChat, the most popular MIM now in China. It has a huge number of registered users, but just only half of them are the "active users". This study intends to examine what factors affect MIM user's continuance intention and actual usage behavior. Design/Methodology/Approach Based on the framework of Perception/Emotion-Behavior and the extended ECM-ISC (Expectation Confirmation Model of IS Continuance), this research introduced some unique variables to a user satisfaction model focusing on perceived/emotional factors in WeChat. In this model, perceived/emotional factors have been divided into enabler factors and inhibitor factors to analyze the effect on continuance intention and actual usage behavior. Also, the moderate effect of the habits was discussed. An online questionnaire survey of 203 WeChat users was conducted and the empirical validation was employed to test the research model. Findings From the empirical results, perceived usefulness, expectation confirmation, and needs for affiliation significantly affected satisfaction. Also, satisfaction influenced continuance intention which led to actual usage behavior. We found that the habit moderates the relationship between satisfaction and continuance intention. The result of this study provides guidance to the developers and operators of WeChat on how to improve enhance users' satisfaction and loyalty.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.2
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• pp.34-46
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• 2002

The purpose of this paper is to investigate the components to be considered when we construct the integrated GIS. Capability has always to be related to application. In this perspective, the range of integrated GIS's capabilities is more extensive than this existing GIS. Using in the case of Japan's local government, when we want to build the integrated GIS, it is necessary to consider the following things. First, the overall manuals are required. Second, the common spatial database should be build to satisfy outsider user as well as inner user. And last, the chief of local government should gain the sympathy of the member of community.

• Journal of Korea Game Society
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• v.13 no.5
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• pp.43-54
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• 2013

With the consistent development of the 3D application technique, visuals are available at more realistic quality and are utilized in many applications like game. In particular, interacting with 3D objects in virtual environments, 3D graphics have led to a substantial development in the augmented reality. This study proposes a 3D user interface to control objects in 3D space through virtual two-view method using only one camera. To do so, homography matrix including transformation information between arbitrary two positions of camera is calculated and 3D coordinates are reconstructed by employing the 2D hand coordinates derived from the single camera, homography matrix and projection matrix of camera. This method will result in more accurate and quick 3D information. This approach may be advantageous with respect to the reduced amount of calculation needed for using one camera rather than two and may be effective at the same time for real-time processes while it is economically efficient.

• Journal of the Korea Computer Graphics Society
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• v.21 no.3
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• pp.17-26
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• 2015

In this paper, we explain a volume rendering system for client-server environment. A single GPU-equipped PC works as a server which is based on the ideas that only a few concurrent users use a volume rendering system in a small hospital. As the clients, we used Android mobile devices such as smart phones. User events are transformed to rendering requests by the client application. When the server receives a rendering request, it renders the volume using the GPU. The rendered image is compressed to JPEG or PNG format so that we can save network bandwidth and reduce transfer time. In addition, we perform an event pruning method while a user is dragging the touch to enhance latency. The server compensates the pruning by interpolating the touch positions. As the result, real-time volume rendering is possible for 5 concurrent users on single GPU-equipped commodity hardware.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.4
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• pp.457-477
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• 2010

Currently, collections with public libraries are evaluated only on the basis of simple data, such as the use volume of collections with individual libraries, and interlibrary lending (ILL) results. To promote the ILL of regional libraries and raise the use of collections, however, the evaluation of collections should be expanded from individual libraries to regional libraries. This study aims to propose user-oriented methods for evaluating the library collections within a regional library system by using four kinds of data: collection, acquisition, circulation, and ILL application data. The results of this study show that the proposed method can reveal the positions of each library within a regional library system, and also the characteristics of a library's collections and users' needs more precisely.

• Journal of Digital Contents Society
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• v.19 no.9
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• pp.1819-1824
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• 2018

This paper proposes a control method of ASMR(autonomous sensory meridian response) contents to relieve user's stress and improve his attention. The proposed method measures EEG(electroencephalography), attention, meditation, and eyeblink data from an EEG device and sends them to an oneM2M-compliant IoT(internet of things) server platform through an Android IoT Application. Then a SVM(support vector machine) model is built to classify user's mental health status by using EEG, attention and meditation data collected in the server platform. The ASMR contents are controlled by the mental health status classified by a SVM model and the eyeblink data. When comparing the SVM models according to types of data used, the SVM model with attention and meditation data showed accuracy of 85.7%. It was verified that the proposed control algorithm of ASMR contents properly worked as the mental health status from the SVM model and the eyeblink data changed.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.9
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• pp.615-620
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• 2013

With the development of smartphones, the number of applications for smartphone increases sharply. As a result, users need to try several times to find their favorite apps. In order to solve this problem, we propose a recommendation system to provide an appropriate app list based on the user's log information including time stamp, location, application list, and so on. The proposed approach learns three recommendation models including Naive-Bayesian model, SVM model, and Most-Frequent Usage model using temporal and spatial attributes. In order to figure out the best model, we compared the performance of these models with variant features, and suggest an hybrid method to improve the performance of single models.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.45-54
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• 2010

In this paper, we propose a quality interworking control system to enhance user's quality satisfaction in NGN environment by controling QoS parameters related with QoE in network layer when service user's QoE using variance multimedia service is poor. The proposed system gathers QoS parameter information in network layer through control packet such as RTCP, and evaluates QoE of multimedia service using these QoS parameter information. Comparing the evaluated QoE with the measured QoE in application layer, QCS judges quality degradation, deduces related QoS parameters and decides relative importance of each parameter when QoE is lower than threshold value. QCS generates QoS control values which is based on routing and switching policy in service quality control system(SCS) and forwards them to SCS. Through this proposed system, service and network providers can provide multimedia services of enhanced quality to service users taking account of service characteristic and network performance.