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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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Journal DOI :
Korea Multimedia Society
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Volume & Issues
Volume 5, Issue 6 - Dec 2002
Volume 5, Issue 5 - Oct 2002
Volume 5, Issue 4 - Aug 2002
Volume 5, Issue 3 - Jun 2002
Volume 5, Issue 2 - Apr 2002
Volume 5, Issue 1 - Feb 2002
Selecting the target year
An Improved Contrast Control Method for LCD Monitor
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 609~615
In this paper, we propose a contrast for the improvement of multi-gray scale image on display system. The proposed method distinguishes a maximum value and a minimum value in input fields or frames. By this judgement, the improvement degree of image quality is decided. This method does not require field and frame memory. Moreover, its lower hardware complexity than conventional methods make it easy to apply this method for flat panel display(FPD) which requires real-time processing. And the contrast of input gray level can be controled flexibly by varying the weight the weight value which controls the contrast range. The proposed method gives an image by controlling weighting slope selectively at intervals according to the brightness-control algorithm and the type of image in the look-up table. The function of the proposed method has been verified through Synopsys VHDL and computer simulation. And its results show that the proposed method can improve the quality of image.
A Study on Extraction of Central Objects in Color Images
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 616~624
An extraction method of central objects in the color images is proposed, in this paper. A central object is defined as a comparatively consist of the central object in the image. First of all. an input image and its decreased resolution images are segmented. Segmented regions are classified as the outer or the inner region. The outer region is adjacent regions are included by a same region in the decreased resolution image. Then core object regions and core background regions are selected from the inner region and the outer region respectively. Core object regions are the representative regions for the object and are selected by using the information about the information about the region size and location. Each inner regions is classified into foreground or background regions by comparing values of a color histogram intersection of the inner region against the core object region and the core background regions. The core object region and foreground regions consist of the central object in the image.
A Design and Implementation of the Realtime Video Lecture System for Multimedia Education
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 625~637
The Internet had been taken properties which were both a slow speed and low-bandwidth of the first time. It was impossible to transmit large multimedia data because of a Internet properties. After tens of Year Passed, many people began to transmit multimedia data in the Internet which had fast-speed and high-bandwidth. Some people want to team classes to be taught in school through the Internet. And, educators wish to use multimedia data in the educational field. Due to previous reasons, many parts in the educational field had tried to join real-time objects to multimedia objects. But, real-time data didn’t appear easily due to many faults like network errors and system bugs if we want to control data in order to teach and learn classes. Then, this paper separates real-time and unreal-time data and controls these data that aye made a time scheduler to have time information in the extended SMIL-file for deceasing these faults.
Design and Implementation of Multimedia Supported SPRT System
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 638~645
One of the potential advantages of computer-based instruction is individualization of instruction. However, this goal has not been fully realized in practice, due largely to limitations of natural language understanding and to combinatorial explosion. It is nonetheless possible to develop CAT(Computer- based Adaptive Testing) Programs which can adapt to students, depending on their performance, by adjusting the length of computer-based tests. The number of questions can be significantly reduced for many individuals, while mastery and nonmastery decisions remain highly accurate. In this paper, We design and implement a Diagnosis System using SPRT(Sequential Probability Ratio Testing). This system supports multimedia object, client/server environment, indvidual feedback, multi-SPRT and maintain student model for individualization of instruction. besides, this system measures coefficient alpha of each problem.
A Study on Tactile Sensation Application for Computer Game and Virtual Reality
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 646~654
The human sense of touch provides us with an important source of information about our surroundings. Because of its unique position at interface between our bodies and the out world, touch sensation supplies sensory data which helps us manipulate and recognize objects and warn of harmful situation. But tactile sensation was recognized less important than visual sense and auditory sense but it plays an important immersing role in virtual reality and computer game. Tactile sensation can be used to influence to objects according to power and supplied sensory feedback to the player in a virtual environment. This paper investigated the characteristics of tactile sensation of human being and proposed method of sturdy using force sensing sensor, simple force modeling and data structure form for virtual reality and computer game. As a result, force distribution, depth, center point can be calculated using sensor output and this information is very effective to specific position for actions and reactions. This study can used as basic information for tactile sensation and it's application in computer game and virtual realty.
Design and Implementation of a Web-based 3D Virtual Gallery using Panorama Images
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 655~664
In this paper, we implemented a web-based 3D virtual pottery gallery Using VR authoring tools. With this system, we expect to cause learning motives and Provide more realistic and interactive learning space. Out system was implemented by making panorama images and 3D object modules using Photo Vista. Object Modeler and Reality Studio. Users can connect to this web site(http://artstory.x-y.net), rotate a pottery panoramically, and zoom it in or out. We designed this virtual gallery can have beneficial influence on students' aesthetic aspects through realistic work appreciations in their art education processes.
A Block Cipher Algorithm based on Cellular Automata
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 665~673
In this paper, we introduce cellular automata and propose a new block cipher algorithm based on cellular automata. For the evaluation of performance and security, we compare the results of the proposed algorithm with them of the standard block ciphers such as DES, Rijndael regarding on avalanche effects and processing time, and analyze the differential cryptanalysis for a reduction version of the proposed algorithm. In addition, we perform the statistical tests in FIPS PUB 140-2(Federal Information Processing Standards Publication 140-2) for the output bit sequences of proposed algorithm to guarantee the randomness property.
A Secure Agent of Integrated Administration System for the Electronic Commerce
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 674~682
Nowadays economic and commercial businesses have been increased because of the Internet. As a result of this, electronic commerce is becoming one of the most Interesting topic of discussion. Electronic commerce is equal to a real market, only the place of business is the imaginary space supported by the Internet. There are a few conditions to consider, making electronic commerce work safely. The electronic commerce should be connected by a substantial system and an on-line Protocol. There are some conditions needed for information security, authentication, and payment by electronic currency etc. Although there are many kinds of existing systems, which create services successfully, further research for security is required. Therefore, this paper suggests an authenticated Agent management, which offers more convenience and security than before. Also, this paper shows many authenticated methods for a management system. An Agent that is one of interesting things to study can handle information problems and works related to electronic commerce.
Design and Evaluation of A Block Encryption Algorithm using Dynamic-Key
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 683~696
The existing block encryption algorithms have been designed for the encryption key value to be unchanged and applied to the round functions of each block, and enciphered. Therefore, it has such a weak point that the plaintext or encryption key could be easily exposed by differential cryptanalysis or linear cryptanalysis, both are the most powerful methods for decoding block encryption of a round-repeating structure. In order to overcome with this weak point, an encryption algorithm using a mote efficient key should be designed. In this paper, a block encryption algorithm which is designed for each encryption key value to be applied to each round block with different value is proposed. This algorithm needs a short processing time in an encryption and decryption, has a high intensity, can apply to electronic commerce and various applications of data protection.
Adaptive Multi-stream Transmission Technique based on SPIHT Video Signal
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 697~703
In this paper, we propose the adaptive multi stream transmission technique based on SPIHT video signal for the highest quality service over the current Internet that does not guarantee QoS. In addition to the reliable transmission of the video stream over the asynchronous packet network, the proposed approach provides the transmission using the adaptive frame pattern control and multi steam over the TCP for continuous replay. The adaptive frame pattern control makes the transmission date scalable in accordance with the client's buffer status. Apart from this, the multi stream transmission improves the efficiency of video stream, and is robust to the network jitter problem, and maximally utilizes the bandwidth of the client's. As a result of the experiment, the DR(delay ratio) in the proposed adaptive multi-stream transmission is more close to zero than in the existing signal stream transmission, which enables the best-efforts service to be implemented.
Petri Nets Modelling and Performance Analysis of Multimedia Mobile Communication Systems for Channel Allocations
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 704~711
Multimedia communication systems are characterized by supporting three different typer of services such as circuit switched services, and packet switched real Lime and non real time services. The wireless channels in a cell ate allocated by calls of these different service classes and the different service requirements have to be met. SRN is an extension of stochastic Petri nets and provides compact Modeling facilities for system analysis. To get the performance index, appropriate reward rates are assigned to its SRN. In this paper, we present a SRN model for performance analysis of channel allocation of multimedia mobile communication systems. The key contribution of this paper constitutes the Petri nets modeling techniques instead of complicate numerical analysis of Markov chains and easy way of performance analysis for channel allocations under SRN rewards concepts.
A Study on E-Marketplace Solution Selection Factors
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 712~729
In this study, we evaluated degree of importance of e-marketplace solution selection factors. Factor analysis was conducted to find out relationships among various variables which come from literature survey. The result shows that 16(sixteen) -selection variables regarding solution characteristics could be grouped into four areas 'flexibility', 'ease of use', 'security', and 'economy'. And 11(eleven) selection variables regarding to vendor characteristics could be grouped into three areas, 'vendor's support', vendor's general situation', and 'vendor's business accomplishment`. Through various analysis, we found important factors for 3 types of operational companies, buyer-biased, seller biased and neutral. 'Security for data item' was showed as the most important factor for all kind of B2B operational companies. For buyer-biased companies, additional supporting manpower, solution education, and educational cost are shown to be more important factors than others. Place of education, education hours and education level are important for 'Neutral' companies. And the factor 'market share of vendor' are important for 'seller biased' companies.
Navigational Structure and User Behavior Modeling for Restructuring of Web-based Information Systems
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 730~744
A Web-Based Information System(WBIS), a typical structure of recently information systems, should be dynamically restructured in order to satisfy user's need and make a profit. Thus, we should analyze and modelize the navigational structure of WBIS and utilize it by modeling the navigational structure of behavior of user through log-file as system restructuring. In this paper, we propose the modeling method for navigational structure and user behavior to restructure WBIS including shopping mall. Also, we suggest the structural model, state transition model, Petri net model and analysis method and analyze and implement modeling algorithm for user behavior to analyze log-file of it. Then, we propose some restructuring heuristic and apply the methods to the example of WBIS.
Efficient Bidirectional Search Algorithm for Optimal Route
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 745~752
A* algorithm is widely used in optimal car route search which is a kind of informed search, since the locations of starting and ending points are known a priori. Unidirectional A* algorithm requires considerable search time but guarantees a optimal path, bidirectional A* algorithm does not guarantee a optimal path and takes even longer search time than unidirectional search to guarantee a optimal path. In this paper, a new bidirectional A* algorithm which requites less search time and guarantees a optimal path is proposed. To evaluate the efficiency of the proposed algorithm, several experiments are conducted in real road map and the results show that the algorithm is very effective in terms of finding a optimal path and search time.
Design of A 3V CMOS Programmable Gain Amplifier for the Information Signal Processing System
Journal of Korea Multimedia Society, volume 5, issue 6, 2002, Pages 753~758
In this paper, low voltage 3V CMOS programmable gain amplifier(PGA) for using in the transmitter and receiver of ADSL analog front-end is designed. The designed receive PGA is connected with 1.1MHz continuous lowpass fillet and controls the gain from 0dB to 30dB. And also the transmitter PGA is connected with 138KHz lowpass filter and controls the gain from -15dB to 0dB. The gain of All PGAs can be programmed by digital logic circuits and main controller. The designed PGAs are verified using HSPICE simulation with