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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Korea Multimedia Society
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Korea Multimedia Society
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Volume & Issues
Volume 12, Issue 12 - Dec 2009
Volume 12, Issue 11 - Nov 2009
Volume 12, Issue 10 - Oct 2009
Volume 12, Issue 9 - Sep 2009
Volume 12, Issue 8 - Aug 2009
Volume 12, Issue 7 - Jul 2009
Volume 12, Issue 6 - Jun 2009
Volume 12, Issue 5 - May 2009
Volume 12, Issue 4 - Apr 2009
Volume 12, Issue 3 - Mar 2009
Volume 12, Issue 2 - Feb 2009
Volume 12, Issue 1 - Jan 2009
Selecting the target year
Update Method based on Dynamic Access-Frequency Tree in Grid Database System
Shin, Soong-Sun ; Back, Sung-Ha ; Lee, Yeon ; Lee, Dong-Wook ; Kim, Gyoung-Bae ; Chung, Worn-Il ; Bae, Hae-Young ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1191~1200
The replicas in the Grid database is utilized for a lot of application services. And for deferent services or for deferent information depends on location, the access frequency of each replica is dissimilar. When one replica is stored in many nodes, each replicas applies the week-consistency in the grid computing environment. Especially, when a node work load or operation capacity is varied from others, the replica management would cost expansive. Therefore, this paper proposed the Update Method based on Dynamic Access-Frequency Tree. The dynamic access-frequency tree is pre-constructed by grouping nodes based on each nodes access frequency to manage the replica efficiently and avoid unbalance replica tree. The performance evaluation shows the proposed methods support more quick update than current methods.
Fast Channel Changing Technique to Deliver Enhanced IPTV User Experience
Song, Young-Ho ; Kwon, Taeck-Geun ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1201~1209
Recently, the convergence of the telecommunications industry through the development of network media has brought along interactive data services in addition to the traditional broadcast services by providing direct connections between the users and the broadcasters. This can be easily achieved by the combination of existing network technology and multimedia technology, but in reality, as seen in the actual implementation of IPVT, it's difficult to provide satisfactory levels of service to users due to issues of network bandwidth and problems of streaming system. In particular, a network which is able to fully support Qos/QoE, and also a fast enough channel changing technology that is satisfactory to the user, are prerequisites for IPTV success. Therefore this thesis proposes a fast channel changing technique to delivery enhanced IPTV user experience. Recent IP set-top-boxes use only a small portion of the CPU to feed Ethernet packets to the hardware decoder and play them. Thus, by making IP set-top-boxes share cached channel information and content with each other, reducing the load on the server and enhancing the channel changing time is made possible.
Convergence Analysis of Adaptive L-Filter
Kim, Soo-Yong ; Bae, Sung-Ho ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1210~1216
In this paper we analyze the convergence behavior of the recursive least rank (RLR) L-filter. The RLR L-filter is an order statistics filter, filter coefficients of which are the weights according to the order of magnitude of inputs. And RLR L-filter is a non-linear adaptive filter, that uses RLR algorithm for coefficient updating. The RLR algorithm is a non-linear adaptive algorithm based on rank estimates in Robust statistics. The mean and mean-squared convergence behavior of the RLR L-filter is examined with variable step-sizes. The RLR L-filter adapts the median filter type to the heavy-tailed distribution function of impulse noise, and adapts the average filter type to Gaussian noises.
Semi-automatic 3D Building Reconstruction from Uncalibrated Images
Jang, Kyung-Ho ; Jang, Jae-Seok ; Lee, Seok-Jun ; Jung, Soon-Ki ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1217~1232
In this paper, we propose a semi-automatic 3D building reconstruction method using uncalibrated images which includes the facade of target building. First, we extract feature points in all images and find corresponding points between each pair of images. Second, we extract lines on each image and estimate the vanishing points. Extracted lines are grouped with respect to their corresponding vanishing points. The adjacency graph is used to organize the image sequence based on the number of corresponding points between image pairs and camera calibration is performed. The initial solid model can be generated by some user interactions using grouped lines and camera pose information. From initial solid model, a detailed building model is reconstructed by a combination of predefined basic Euler operators on half-edge data structure. Automatically computed geometric information is visualized to help user's interaction during the detail modeling process. The proposed system allow the user to get a 3D building model with less user interaction by augmenting various automatically generated geometric information.
Bone Region Extraction by Dual Energy X-ray Absorbtion Image Decomposition
Kwon, Ju-Won ; Cho, Sun-Il ; Ahn, Young-Bok ; Ro, Yong-Man ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1233~1241
Over the 50 percents of women who are older than 45 years have osteoporosis. Because people hardly recognize this disease by themselves, the researches that measure bone mineral density have been doing widely to detect osteoporosis in the early stage. The most widely used methods for bone mineral density measurement are based on the X-ray imaging. Among them, DEXA(Dual-energy X-ray Absorptiometry) imaging is one of the important methods in bone mineral density measurement. DEXA images are useful methods to increase diagnosis efficiency by reducing anatomic noise as two images obtained from two different energy levels. However, it has some problems to a calibration parameter determined by the heuristic method for bone extraction. In this paper, we propose the method to extract bone in DEXA image using calibration parameter based on anatomic attenuation coefficient. The experimental results reveal that the proposed method is effective.
Load balancing method of overload prediction for guaranteeing the data completeness in data stream
Kim, Young-Ki ; Shin, Soong-Sun ; Baek, Sung-Ha ; Lee, Dong-Wook ; Kim, Gyoung-Bae ; Bae, Hae-Young ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1242~1251
A DSMS(Data Stream Management System) in ubiquitous environment processes huge data that input from a number of sensor. The existed system is used with a load shedding method that is eliminated with a part of huge data stream when it doesn't process the huge data stream. The Load shedding method has to filter a part of input data. This is because, data completeness or reliability is decreased. In this paper, we proposed the overload prediction load balancing to maintain data completeness when the system has an overload. The proposed method predicts the overload time. and than it is decreased with data loss when achieves the prediction overload time. The performance evaluation shows that the proposed method performs better than the existed method.
Conversation Context Annotation using Speaker Detection
Park, Seung-Bo ; Kim, Yoo-Won ; Jo, Geun-Sik ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1252~1261
One notable challenge in video searching and summarizing is extracting semantic from video contents and annotating context for video contents. Video semantic or context could be obtained by two methods to extract objects and contexts between objects from video. However, the method that use just to extracts objects do not express enough semantic for shot or scene as it does not describe relation and interaction between objects. To be more effective, after extracting some objects, context like relation and interaction between objects needs to be extracted from conversation situation. This paper is a study for how to detect speaker and how to compose context for talking to annotate conversation context. For this, based on this study, we proposed the methods that characters are recognized through face recognition technology, speaker is detected through mouth motion, conversation context is extracted using the rule that is composed of speaker existing, the number of characters and subtitles existing and, finally, scene context is changed to xml file and saved.
An Enhancement Technique for Separation of Direct Light and Global Light Using High Frequency Illumination pattern
Jo, Mi-Ri-Na ; Park, Dong-Gyu ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1262~1272
In computer graphics, there exist many studies about illumination and radiance for a realistic description of the 3D modeling and rendering. When we see a scene, the scene is lit by a source of light and the radiance of the points by a source in the scene. The radiance has direct light and glight component. The direct light gets lights directly from light source, but the global light gets lights indirectly by interreflections among complicated geometrical components. In this paper, we studied a method for increasing the accuracy of separating direct light and global light components from a scene by using high frequency illumination pattern. For experiments, we applied the separating method of Nayar's and found the best configurations for the separation through the experiments. We improved the separation accuracy of direct and global light by measuring the value of unilluminated area, which depends on the characteristics of object. Furthermore, we enhanced invisible scene of the global light by applying the image filtering technique.
Pre-cluster HEAD Selection Scheme based on Node Distance in Chain-Based Protocol
Kim, Hyun-Duk ; Choi, Won-Ik ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1273~1287
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.
Multi Frequency Thin Film Loop Antenna for Multi-media Devices
Shin, Cheon-Woo ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1288~1296
This paper is for multi-frequency thin film loop antenna used on smart phone, PMP and PDA like as a multi-media devices. We developed a loop pattern folding methods to reduce a thin film antenna dimension using that mutual coupling folding loop occurs the higher frequency resonation. To reduce the thin film size for loop antenna, we fold the loop pattern repeatedly control the coupling coefficient than generate a not only higher mode resonation but also basic resonation from loop pattern. To realization the thin film folded loop antenna, we used a
PI film the thickness is 20um so that we realize the CDMA850, GPS, DCS, PCS, WCDMA antenna simultaneously and it's radiation efficiency is over 50% and gain is 0dBi.
An Energy-Efficient Topology Control Scheme based on Application Layer Data in Wireless Sensor Networks
Kim, Seung-Mok ; Kim, Seung-Hoon ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1297~1308
The life time of a wireless sensor network composed of numerous sensor nodes depend on ones of its sensor nodes. The energy efficiency operation of nodes, therefore, is one of the crucial factors to design the network. Researches based on the hierarchical network topology have been proposed and evolved in terms of energy efficiency. However, in existing researches, application layer data obtained from sensor nodes are not considered properly to compose cluster, including issue that nodes communicate with their cluster heads in TDMA scheduling. In this paper, we suggest an energy-efficient topology control scheme based on application layer data in wireless sensor networks. By using application layer data, sensor nodes form a section which is defined as the area of adjacent nodes that retain similar characteristics of application environments. These sections are further organized into clusters. We suggest an algorithm for selecting a cluster head as well as a way of scheduling to reduce the number of unnecessary transmissions from each node to its cluster head, which based on the degree and the duration of similarity between the node's data and its head's data in each cluster without seriously damaging the integrity of application data. The results show that the suggested scheme can save the energy of nodes and increase the life time of the entire network.
The Study on Improvement of the Program that Traces the Binary Codes in Execution
Chang, Hang-Bae ; Kwon, Hyuk-Jun ; Kim, Yang-Hoon ; Kim, Guk-Boh ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1309~1315
This research goal of developing and producing a tool that finds security weakness that may happen when a usual program is executed. The analyzing tool for security weakness has the major functions as follows. In case that a part of anticipated security weakness are in execution, it traces a machine language to a part in execution. And Monitoring System calls and DLL(API) calls when a program is in execution. The result of this study will enable to contribute to use as educational materials for security service in companies and related agencies and to prevent from hacking of external information invaders in the final analysis.
An Equalization Method in Filtered Multitone Modulation based on the ISI Estimation
Ryu, Jung-Hun ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1316~1322
The multicarrier system is in the limelight for broadband wireless communications due to its spectral efficiency. Filtered multitone(FMT) system uses a filter that has several symbol periods duration. Using long-period filter causes a performance degradation because of intersymbol interference in multipath fading channels. In this paper, we propose a simple equalization method which can reduce the ISI due to the wireless channels. The proposed equalization method compensates the ISI by subtracting the estimated ISI components from the current symbol using one-tap equalizer. The performance of the proposed system is verified through theoretical analysis and simulation results show that the proposed system can mitigate the effect of ISI significantly.
Fast and Secure 2-Way Handshake Mechanism using Sequence Number in Wireless LAN
Lim, Jeong-Mi ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1323~1332
In this paper, we analyze security weakness of 4-Way Handshake in IEEE 802.11i and propose fast and secure 2-Way Handshake mechanism. Compute PTK(Pairwise Transient Key) using sequence number instead of random numbers in order to protect Replay attack and DoS attack. Also, proposed 2-Way Handshake mechanism can mutual authenticate between mobile station and access point and derive PTK using modified Re-association Request and Re-association Response frames. And, compare with others which are fast and secure Handoff mechanisms.
Learning Heuristics for Tactical Path-finding in Computer Games
Yu, Kyeon-Ah ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1333~1341
Tactical path-finding in computer games is path-finding where a path is selected by considering not only basic elements such as the shortest distance or the minimum time spend but also tactical information of surroundings when deciding character's moving trajectory. One way to include tactical information in path-finding is to represent a heuristic function as a sum of tactical quality multiplied by a weighting factor which is.. determined based on the degree of its importance. The choice of weighting factors for tactics is very important because it controls search performance and the characteristic of paths found. In this paper. we propose a method for improving a heuristic function by adjusting weights based on the difference between paths on examples given by a level designer and paths found during the search process based on the CUITent weighting factors. The proposed method includes the search algorithm modified to detect search errors and learn heuristics and the perceptron-like weight updating formular. Through simulations it is demonstrated how different paths found by tactical path-finding are from those by traditional path-finding. We analyze the factors that affect the performance of learning and show the example applied to the real game environments.
Implementation of Digital Folding Screen System for Information Visualization Based on Web
Choi, Jeong-Hee ; Yun, Chang-Ok ; Lee, Dong-Hoon ; Yun, Tae-Soo ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1342~1350
Until today, the uses of digital display system mostly included demonstration, observation, and exhibition of simple images. The strengths were that the images that changes in line with the music played could be reinterpreted as a different work. Also, it could stimulate the sensibility of the users. However, the range of the uses of the system is very limited and users could easily lose their interest. Therefore, it is necessary to develop a system that could continuously induce and motivate user interaction. Therefore, the RSS based digital folding screen system proposed by this paper has an objective of being used as an interactive media system which overcome the limitations of former eight-sided folding screen used for simple observation purposes. It also applied the main function of RSS in which the user could collect and read newly registered messages without visiting the blogs or corresponding websites. Therefore, it is capable of sending the information needed by the user. Generally, we can observe the contents for mere observation purposes and when necessary, it could also be utilized for advertisement or exhibition purposes. It could also be used as a information transfer system in public facilities.
An Architecture for Testing the Interoperability among Defense Weapon Systems Software
Han, Ik-Joon ; Bang, Chun-Sik ; Yoon, Gwang-Sik ; Bae, Hyun-Seop ; Ryu, Dong-Kuk ;
Journal of Korea Multimedia Society, volume 12, issue 9, 2009, Pages 1351~1362
The importance of interoperability in modem warfare has been increasing ever since. Korean Ministry of National Defense has constructed and used the Systems Interoperability Test & Evaluation System in order to evaluate level of interoperability among defense information systems. However, as primary targets of SITES were information systems, there is limitation to be applied to weapon systems. This paper proposes an interoperability testing architecture and interoperability testing configuration items which encompass various aspects of interoperability testing. We developed a prototype which proved that the proposal can be realized and useful.