• Journal of Korea Multimedia Society
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• v.14 no.6
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• pp.730-741
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• 2011

With the development of the internet and computer technology, the amount of information through the internet is increasing rapidly and it is managed in document form. For this reason, the research into the method to manage for a large amount of document in an effective way is necessary. The conventional document categorization method used only the keywords of related documents for document classification. However, this paper proposed keyword extraction method of based on association rule. This method extracts a set of related keywords which are involved in document's category and classifies representative keyword by using the classification rule proposed in this paper. In addition, this paper proposed the preprocessing method for efficient keywords creation and predicted the new document's category. We can design the classifier and measure the performance throughout the experiment to increase the profile's classification performance. When predicting the category, substituting all the classification rules one by one is the major reason to decrease the process performance in a profile. Finally, this paper suggested automatically categorizing plan which can be applied to hierarchical category architecture, extended from simple category architecture.

• Journal of Korea Multimedia Society
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• v.12 no.9
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• pp.1273-1287
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• 2009

PEGASIS, a chain-based protocol, forms chains from sensor nodes so that each node transmits and receives from a neighbor. In this way, only one node (known as a HEAD) is selected from that chain to transmit to the sink. Although PEGASIS is able to balance the workload among all of the nodes by selecting the HEAD node in turn, a considerable amount of energy may be wasted when nodes which are far away from sink node act as the HEAD. In this study, DERP (Distance-based Energy-efficient Routing Protocol) is proposed to address this problem. DERP is a chain-based protocol that improves the greedy-algorithm in PEGASIS by taking into account the distance from the HEAD to the sink node. The main idea of DERP is to adopt a pre-HEAD (P-HD) to distribute the energy load evenly among sensor nodes. In addition, to scale DERP to a large network, it can be extended to a multi-hop clustering protocol by selecting a "relay node" according to the distance between the P-HD and SINK. Analysis and simulation studies of DERP show that it consumes up to 80% less energy, and has less of a transmission delay compared to PEGASIS.

• Journal of Korea Multimedia Society
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• v.12 no.5
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• pp.708-716
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• 2009

Applications which are implemented on Table Top Display are controlled by hands, so that they support an intuitive interface to users. Users feel the real sense when they interact on the virtual scene in Table Top Display. However, most of conventional augmented reality applications on Table Top Display satisfy only visual sense. In this paper, we propose an interface that supports multi-modal sense in that tactile sense is utilized for augment reality by vibrating a physical control unit when it collides to virtual objects. Users can feel the collision in addition to visual scene. The proposed system facilitates tactile augmented reality through an air hockey game. A physical control unit vibrates when it receives virtual collision data over wireless communication. Since the use of tabletop display environment is extended with a tactile sense based physical unit other than hand, it provides a more intuitive interface.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1347-1352
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• 2015

Smartphone users, opinion experts more than 99 percent of the economically active population is using, it has reached the saturation past the early stages of formation. In this research, we aim to analyze factors influencing of the multimedia function on continue using intention of Smartphone. Predictor factors were selected perceived usefulness, perceived ease of use and perceived enjoyment suggested on extended the technology acceptance model. Participants of this study were 106 Smartphone users in Busan city and Jeonbuk province in accordance with convenience sampling. IBM SPSS Statistics 19 were employed for descriptive statistics, Smart PLS(partial least squares) was employed for confirmatory factor analysis and path analysis of casual relationship among variables and effect. Analytical results show that all paths from perceived value to continue using intention are significant. This study suggests practical and theoretical implications based on the results.

• Journal of Korea Multimedia Society
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• v.10 no.6
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• pp.726-736
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• 2007

In this paper, real-time image scanning system using linescan cameras is designed. The system is specially designed to diagnose and analyse the conditions of tunnels such as crack widths through the captured images. The system consists of two major parts, the image acquisition system and the image merging system. To save scanned image data into storage media in real-time, the image acquisition system has been designed with two different control and management modules. The control modules are in charge of controlling the hardware device and the management modules handle system resources so that the scanned images are safely saved to the magnetic storage devices. The system can be mounted to various kinds of vehicles. After taking images, the image merging system generates extended images by combining saved images. Several tests are conducted in laboratory as well as in the field. In the laboratory simulation, both systems are tested several times and upgraded. In the field-testing, the image acquisition system is mounted to a specially designed vehicle and images of the interior surface of the tunnel are captured. The system is successfully tested in a real tunnel with a vehicle at the speed of 20 km/h. The captured images of the tunnel condition including cracks are vivid enough for an expert to diagnose the state of the tunnel using images instead of seeing through his/her eyes.

• Journal of Korea Multimedia Society
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• v.6 no.3
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• pp.419-428
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• 2003

Several methods have been studied to prune the parasitic branches that cause unfortunately from thinning a shape to get its skeleton. We found that the symmetric path finding method was most efficient because it followed the boundary pixels of the shape just once. In this paper, its extended method is proposed to apply to removing the noise branches that protrude out of the boundary of a segmented or extracted shape in a given image. The proposed method can remove a noise branch with one-pixel width and also remove the noise branch that includes a round shape called a noise blob. The method uses a 4-8-directional boundary-following technique to determine symmetric paths and finds noise branches with noise blobs by detecting quasi-symmetric paths. Its time complexity is a linear function of the number of boundary pixels. Interactively selectable parameters are used to define various types of noise branches flexibly, which are the branch - size parameter and the blob-size parameter. Experimental results for a practical shape and various artificial shapes showed that the proposed method was very useful for simplifying the shapes.

• Journal of Korea Multimedia Society
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• v.14 no.10
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• pp.1287-1302
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• 2011

Clustering protocol that is used in wireless sensor network is an efficient method that extends the lifetime of the network. However, when this method is applied to an environment in which collected data of the sensor node easily overlap, sensor nodes unnecessarily consumes energy. In the case of clustering technique that uses a threshold, the lifetime of the network is extended but the degree of accuracy of collected data is low. Therefore it is hard to trust the data and improvement is needed. In addition, it is hard for the clustering protocol that uses multi-hop transmission to normally collect data because the selection of a cluster head node occurs at random and therefore the link of nodes is often disconnected. Accordingly this paper suggested a cluster-formation algorithm that reduces unnecessary energy consumption and that works with an alleviated link disconnection. According to the result of performance analysis, the suggested method lets the nodes consume less energy than the existing clustering method and the transmission efficiency is increased and the entire lifetime is prolonged by about 30%.

• Journal of Korea Multimedia Society
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• v.9 no.1
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• pp.73-88
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• 2006

With the development of Next Generation convergence Network, the current Internet needs a new network architecture and new session establishment methods, which can support various applications requiring differentiated traffic processing and high quality of service instead of the conventional best-effort service. It is expected that, in next generation network based on All-IP. SIP will play an important role in the session establishment between the end to end user terminals. In this paper, we propose a new network architecture that can provide quality of service based on SIP using the QoS enabled SIP servers and policy servers, and we also propose a new session establishment method that apply the user's demands participating the session establishment when setting up the session using the SIP. Through simulations under various environments, we show the parameter ranges in terms of server capacity and the number of users in access networks to achieve reasonable delay bounds.

• Journal of Korea Multimedia Society
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• v.9 no.10
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• pp.1266-1275
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• 2006

In this paper, we propose a real-lime face detection and tracking algorithm using AdaBoost(Adaptive Boosting) algorithm. The proposed algorithm consists of two levels such as the face detection and the face tracking. First, the face detection used the eight-wavelet feature models which ate very simple. Each feature model applied to variable size and position, and then create initial feature set. The intial feature set and the training images which were consisted of face images, non-face images used the AdaBoost algorithm. The basic principal of the AdaBoost algorithm is to create final strong classifier joining linearly weak classifiers. In the training of the AdaBoost algorithm, we propose SAT(Summed-Area Table) method. Face tracking becomes accomplished at real-time using the position information and the size information of detected face, and it is extended view region dynamically using the fan-Tilt camera. We are setting to move center of the detected face to center of the Image. The experiment results were amply satisfied with the computational efficiency and the detection rates. In real-time application using Pan-Tilt camera, the detecter runs at about 12 frames per second.

• Journal of Korea Multimedia Society
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• v.16 no.9
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• pp.1098-1108
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• 2013

Customizing system is acting a main role for the character production system of MMORPG. However, since using the high degree of freedom in MMORPG, these characters are too individual and lack of awareness. We can describe each character's emotional characteristics and understand the correlation of characters more easily by adjusting design factors capable of cognitive decision to characters. Game character developer should consider seeking efficient character design process that is suitable to MMORPG game environment and users for proper character recognition and promoting character preferences. In addition, this research being extended on the article vol.13, no.3, "A Study on Cognitive and Preference of Games' Character" on Korean Society of Basic Design in June 2012 issue and this study is expected to have effectives as one method for the purpose of this research is to inquire and present what type of relation lies between recognition and preference of game characters of MMORPG.