Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of Digital Contents Society
Journal Basic Information
Journal DOI :
Digital Contents Society
Editor in Chief :
Volume & Issues
Volume 9, Issue 4 - Dec 2008
Volume 9, Issue 3 - Sep 2008
Volume 9, Issue 2 - Jun 2008
Volume 9, Issue 1 - Mar 2008
Selecting the target year
A Study on the Performance of Energy-efficient System with Go-back-N ARQ Protocol in Wireless Home Network Environment
Roh, Jae-Sung ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 1~6
In traditional wireless communication systems the main power consumption is due to the actual transmissions power. Therefore, energy-constrained wireless networks have gained considerable research attention in recent years. Multiple-input-multiple-output (MIMO) structure, or multiple antenna communication is one of the techniques that has gain considerable importance in wireless systems and networks. In this paper, BER and throughput performance of MISO system with Go-back-N ARQ(Automatic Repeat Request) technique in wireless networks are analyzed and the energy consumption of MISO-based wireless networks is compared with conventional SISO-based wireless networks. Obtained results show the applicability of MISO system with Go-back-N ARQ technique in wireless networks with smart system design.
An Implementation of an Agent for Recommending Sensitive Information on Mobile Environment
Park, Eun-Young ; Park, Young-Ho ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 7~15
The paper proposes information system for providing proper well known delicious restaurants as interactions with users. The system calls 'Moloke', which is an agent for recommending sensitive information on mobile environment The proposing agent differs from existing ones that guide the telephone number and the name of the restaurant. The differences are as following goals. First, the agent gets existing from users as interactive communications on mobile devices through the proper requests on each time zone such as morning, afternoon, and evening. Second, the agent also can recommend a specific restaurant for current personal states such as parties, special community meetings, bio-rhythms and so on. Among them, specially the bio-rhythm is used for recommending proper restaurants to each user. In addition to through proposal suitable design for the mobile agent design more effectively. The research used mobile environment for recommendation service and web environment for data management. Server environment for service used Apache, PHP4, Mysql and mobile page was implemented m-html for approach. Mobile Service was optimized Mozilla-1.22, KUN-1.2.3 Browser
Design and Performance Analysis of Adaptive First-Order Decimator Using Local Intelligibility
Kwak, No-Yoon ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 17~26
This paper has for its object to propose AFOD(Adaptive First-Order Decimator) which sets a value of decimated element as an average of a value of neighbor intelligible component and a output value of FOD(First-Order Decimator) for the target pixel, and to analyze its performance in terms of subjective image quality and hardware complexity. In the proposed AFOD, a target pixel located at the center of sliding window is selected first, then the gradient amplitudes of its right neighbor pixel and its lower neighbor pixel are calculated using first order derivative operator respectively. Secondly, each gradient amplitude is divided by the summation result of two gradient amplitudes to generate each local intelligible weight. Next, a value of neighbor intelligible component is defined by adding a value of the right neighbor pixel times its local intelligible weight to a value of the lower neighbor pixel times its intelligible weight. Since the proposed method adaptively reflects neighbor intelligible informations of neighbor pixels on the decimated element according to each local intelligible weight, it can effectively suppress the blurring effect being the demerit of FOD. It also possesses the advantages that it can keep the merits of FOD with the good results on average but also lower computational cost.
Design and Embodiment for Constructing Mobile Medical Information System Combining Bio-sensor and IT Technology
Kim, Heon ; Lee, Sung-Koo ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 27~31
u-Health is a representative realization method of ubiquitous IT and it is being embossed as an industry that can make our lives abundant. Through the u-Health, the diagnosis will go beyond the restriction of space, which is based on hospital, and be positioned as a universal value in a daily life by combining diagnosis and life naturally. The purpose of this study is to suggest systematic, intelligent, mobile medical information system that has the same effect as the assistant of specialist by providing scientific and objective knowledge, which is suitable for u-Health age. Mobile medical information system can provide user with the opinion of specialist by planting the experience, knowledge and decision making process of specialist that are necessary for solving the problem requiring special medical knowledge and passing through an inference process.
The Study of System Security Technique for Mobile Ad Hoc Network
Yang, Hwan-Seok ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 33~39
Mobile Ad Hoc Network is easy to be attacked because nodes are distributed not network based infrastructure. Intrusion detection system perceives the trust values of neighboring nodes and receives inspection on local security of nodes and observation ability. This study applied clustering mechanism to reduce overhead in intrusion detection. And, in order to measure the trust values, it associates the trust information cluster head received from member nodes with its own value and evaluates the trust of neighboring nodes. Secure data transmission is received by proposed concept because the trust of nodes on network is achieved accurately.
Study on the developmental directions of Mobile contents for Mobile e-learning prosumers in Web 2.0 decade
Ahn, Kyung-Whan ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 41~51
In a circumstance that the development of mobile media through the on-line consumer desire in the era of Web 2.0 has promoted extension of personal mobile media on the part of consumers, this study examined consumer trends depending on use of e-learning contents through mobile media. In connection with tendencies through mobile prosumers' consumption patterns and use of mobile educational contents, I analyzed user demands based on characteristics of personal media centering around a communities of e-learning portals. Direction of e-learning technological development calls on mobile communication companies to open their networks and share platform following digital convergence. E-learning contents should be produced in a custom-made way for the personal media. This study is aimed at contributing for advancement of e-learning contents consumers' user convenience implicating examination into consumer demands which are necessary to invigorate e-learning contents.
The Skeletonization of 2-Dimensional Image for Fuzzy Mathematical Morphology using Defuzzification
Park, In-Kue ; Lee, Wan-Bum ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 53~60
Based on similarities between fuzzy set theory and mathematical morphology, Grabish proposed a fuzzy morphology based on the Sugeno fuzzy integral. This paper proposes a fuzzy mathematical morphology based on the defuzzification of the fuzzy measure which corresponds to fuzzy integral. Its process makes a fuzzy set used as a measure of the inclusion of each fuzzy measure for subsets. To calculate such an integral a
-fuzzy measure is defined which gives every subsets associated with the universe of discourse, a definite non-negative weight. Fast implementable definitions for erosion and dilation based on the fuzzy measure was given. An application for robust skeletonization of two-dimensional objects was presented. Simulation examples showed that the object reconstruction from their skeletal subsets that can be achieved by using the proposed was better than by using the binary mathematical morphology in most cases.
A Study on New DCF Algorithm in IEEE 802.11 WLAN by Simulation
Lim, Seog-Ku ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 61~67
In this paper, MAC algorithm for the IEEE 802.11 DCF improving the performance is proposed and analyzed by simulation. The MAC of IEEE 802.11 WLAN to control data transmission uses two control methods called DCF(Distributed Coordination Function) and PCF(Point Coordination Function). The DCF controls the transmission based on CSMA/CA(Carrier Sense Multiple Access with Collision Avoidance), that decides a random backoff time with the range of CW(Contention Window) for each station. Normally, each station increase the CW to double after collision, and reduces the CW to the minimum after successful transmission. The DCF shows excellent performance relatively in situation that competition station is less but has a problem that performance is fallen from throughput and delay viewpoint in situation that competition station is increased. This paper proposes an enhanced DCF algorithm that increases the CW to maximal CW after collision and decreases the CW smoothly after successful transmission in order to reduce the collision probability by utilizing the current status information of WLAN. To prove efficiency of proposed algorithm, a lots of simulations are conducted and analyzed.
Anonymous Pay-Per-View Service for Web-Based Video-on-Demand Systems
Joo, Han-Kyu ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 69~75
Video-on-demand (VOD) service allows subscribers to view any video whenever they want. With the development of the high speed computer networks, web-based VOD services are available. To support VOD services, charging scheme is necessary. Pay-per-view is an effective charging scheme for VOD services. Pay-per-view allows the subscribers to pay for what they have viewed. Privacy is another important attribute for VOD services. The subscribers may not want to reveal what they have viewed to anyone including the VOD provider. Anonymity makes it complicated to calculate charge for the VOD service. An approach that achieves both anonymity and pay-per-view charge calculation is necessary. In this paper, anonymous web-based VOD service is proposed. The proposed approach also gives pay-per-view capability.
Object-Size and Call-Site Tracing based Shared Memory Allocator for False Sharing Reduction in DSM Systems
Lee, Jong-Woo ; Park, Young-Ho ; Yoon, Yong-Ik ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 77~86
False sharing is a result of co-location of unrelated data in the same unit of memory coherency, and is one source of unnecessary overhead being of no help to keep the memory coherency in multiprocessor systems. Moreover, the damage caused by false sharing becomes large in proportion to the granularity of memory coherency. To reduce false sharing in page-based DSM systems, it is necessary to allocate unrelated data objects that have different access patterns into the separate shared pages. In this paper we propose sized and call-site tracing-based shared memory allocator, shortly SCSTallocator. SCSTallocator places each data object requested from the different call-sites into the separate shared pages, and at the same time places each data object that has different size into different shared pages. Consequently data objects that have the different call-site and different object size prohibited from being allocated to the same shared page. Our observations show that our SCSTallocator outperforms the existing dynamic shared memory allocators. By combining the two existing allocation technique, we can reduce a considerable amount of false sharing misses.
A Clustering for Ground Nodes of HAPS Network
Song, Ha-Yoon ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 87~99
High Altitude Platform network systems utilize Unmanned Aerial Vehicle as routers for ground node communication. For this purpose, geographical clustering of ground nodes must be required. In this paper, we assume mobile ground nodes over wide area and the clusters composed of ground nodes are identified. UAVs can be positioned at the point of centroid of clusters. The number of UAVs are derived from the area size and the number of ground nodes deployed in that area. From the simulation and application of clustering algorithms, we showed visual clustering results with dynamic variance of number of ground nodes.
A Study on Designing Method of Framework for NGN QoS Management
Noh, Si-Choon ; Bang, Kee-Chun ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 101~107
The level of transference of NGN is beginning as the operation of Access Gateway in korea at present, but NGN will keep developing continuously to the NGN integrated network until 2010. This research is finding the meaning and assignment of NGN QoS to deduct how to manage the control system and presenting the QoS control process and trial framework. The trial framework is the modeling of the QoS measurement metrics, the measurement time schedule, the section, hierarchy, instrument, equipment and method of measurement and the series of cycle & the methodology about analysis of the result of measurement. The objective standard of quality in communication service is guaranteed not by itself but by controlling and measuring continuously. Especially it's very important time to maintain the research about NGN QoS measurement and control because the big conversion of new network technology paradigm is now spreading.
Discrete construction of generalized derivative functions
Kim, Tae-Sik ; Kim, Kyung-W. ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 109~116
The variation of real phenomena and shape of nature in our world is so complicated that some mathematical tools using the traditional geometric methods based on the Euclidean geometry and analytical differential method may be irrelevant or insufficient in some problems. Recently, to deal with these circumstances, one can use the fractal geometric method. As another measures, in this paper we introduce the non-integral order derivative function for the analytical method and construct to facilitate their calculation.
The Meaning of Guide System in Cyber University in the Era of Web 2.0
Kim, Mi-Jung ; Lee, Hae-Jin ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 117~124
This study aims to propose the futuristic guide system in the Web 2.0 era based on the analysis of past changing guide system in the domestic cyber universities. Guide System is destined to transform its feature and form according to the fast shift of technology and people's way of thinking. The theoretical ground this study took is cognitive psychology, communication theory, especially information design theory.
Distributed Security for Web Application Contents Protection
Heo, Jin-Kyoung ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 125~130
User web service is increasing by development of internet technology. Quantity of encrypted data that transmitted through the network are increasing by development of encipherment technology. We have many problems; it is caused by technical development and service increase of user requests. It is like that, we have reliability of contents and illegality copy problem of internet contents in web application system. It is contents protection skills in web that encipherment technology, authentication and digital signature. We need message encoding and secret key for solve vulnerability of encipherment in web application system. In this paper, we propose a distributed secure system that can data confidentiality and user authentication. It prevent performance degradation from bottle neck in encipherment server, and improve service quality.
Analysis of the Emergence of Interactive Art in Art and Artificial Life
Kim, Hee-Young ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 131~137
The salient features of interactive art development through the participation of spectators in the late 20th century could be creativity and possibility of future growth by biological factors. With the development of artificial life studies, Interactive art holds a position in the biological developmental stage, but relevant studies have not been active. This study analyzes three representative case studies located in the emergent stages of development and examines the traits closely so that the foundation of developmental direction of emergent property would be clarified.
Design and Implementation of ICT Ethics Behaviour Test System
Baek, Hyeun-Ki ; Ha, Tai-Hyun ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 139~147
It is difficult to prevent and solve the contrary function of informationized society by a coercive or physical way. It is believed that a systematic education, teachers, experts, parents and students of schools are to be united as one to put every effort on preventing the contrary function of informationized society. In this study, ICT ethics behaviour test system has been designed and implemented with the aim of setting up an appropriate sense of values and cultivating ICT ethics index of juveniles. ICT ethics behaviour test system developed is to meet the contrary function of informationized society actively so the system should prevent the negative phenomenon derived from it. And it is expected to help the system build up the ability of keeping and developing the primary function of informationized society.
Design and Implementation of 3D Facial Aesthetic Surgery System
Cho, Sae-Hong ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 149~155
This paper is a study and implementation of 3D facial aesthetic surgery system using 3D graphic technology. First, this system shows 3D shape of face which is close to the real face of human by using Pre-Processing and Face-Part-Making modules. Three-dimensional Facial Aesthetic Surgery System is also designed and implemented. Each controller controls the degree of changes for the corresponding part of face. The implemented 3D Facial Aesthetic Surgery System in this paper shows more accuracy, effectiveness and satisfaction in compare with 2D Facial Aesthetic Surgery System that is used in the hospital.
A Chart Generator using XML
Yun, Hyun-Mim ; Kim, Hyung-Il ;
Journal of Digital Contents Society, volume 9, issue 1, 2008, Pages 157~164
As use of internet gets increased, the efficiency of applying the chart which is expressing and providing information through web is increased. The chart has the high delivering ability of information because it expresses data visually. But there are problems such as compatibility between the chart composing programs, difficulty of sharing the chart data, and displaying the chart on the web. In this paper, we propose the chart markup language, which expresses the chart information by using the XML in order to solve problems of compatibility of the chart expression and sharing the chart information. The CML is possible not only to provide compatibility between platforms and programs but also to share the chart data as it is based on the XML.