• The KIPS Transactions:PartC
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• v.9C no.1
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• pp.73-78
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• 2002

In WATM networks, in order to perform dynamic slot allocation required slots of mobile terminals are estimated based on DP (Dynamic Parameter) reflecting characteristics of traffic. In VBR (Variable Bit Rate) traffic, slot allocation is done at MT considering both time-dependent characteristics and QoS (Quality of Service) requirements. In this paper, DPs-buffer state information and buffer state change-are transmitted through in-band signaling. BS (Base Station) performs dynamic slot allocation considering traffic characteristics of each MT (Mobile Terminal), in other words, buffer state information informs the potentiality of 'buffer full state'to BS if MT buffer is over the specific threshold value and buffer state change notifies change in buffer state of incoming cells to MT. If buffer state information is equal to 'low (more than threshold)' and 'abrupt increase' it generates 'buffer full' state cell transmission delay or cell loss might occur. At this time BS should assign additional slots to MT, and then MT consumes cells in its buffer. In simulation, the proposed scheme shows better performance in cell delay and loss than EPSA (Estimation-Prorated Slot Assignment) in-band scheme.

• The Transactions of the Korea Information Processing Society
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• v.4 no.7
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• pp.1770-1780
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• 1997

Our problem is improvement of image quality because it is inevitable cell loss of image data when traffic congestion occurs. If cells are discarded indiscriminately in transmission of MPEG video data, it occurs severe degradation in quality of service(QOS). In this paper, to solve this problem, we propose two method. The first, we analyze the traffic characteristics of an MPEG encoder and generate high priority and low priority data stream. During network congestion, only the least low priority cells are dropped, and this ensures that the high priority cells are successfully transmitted, which, in turn, guarantees satisfactory QoS. In this case, the prioritization scheme for the encoder assigns components of the data stream to each priority level based on the value of a parameter ${\beta}$. The second, Number of high priority cells are increased when value of ${\beta}$ is large. It occurs the loss of high priority cell in the congestion. To prevent it, this paper is regulated to data stream rate as buffer occupancy with UPC controller. Therefore, encoder's bandwidth can be calculated renegotiation of the encoder and networks. In this paper, the encoder's bandwidth requirements are characterized by a usage parameter control (UPC) set consisting of peak rate, burstness, and sustained rate. An adaptive encoder rate control algorithm at the Networks Interface Card(NIC) computes the necessary UPC parameter to maintain the user specified quality of service. Simulation results are given for a rate-controlled VBR video encoder operating through an ATM network interface which supports dynamic UPC. These results show that dynamic bandwidth renegotiation of prioritized data stream could provided bandwidth saving and significant quality gains which guarantee high priority data stream.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.2
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• pp.443-449
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• 2015

In this paper, we proposed Channel allocation scheme according to the user's location with IR. In VLC System, LED can generate various colors of light by controlling the mixing ratio of each individual RGB color element. Thus, each RGB channel will have a different signal power, and each channel will have different performance. This proposed system using Visible light(RGB) as way to transmit signals, it depends on the mixture RGB, which decided the color of light, moreover, each things determined their performance. However, if the signal were fixed allocated RGB to transmit such as the original system, the importance of the each signals a different occur the limit on the quality of signals. To solve this problem in this paper, according to the RGB mixture ratios analyze the performance for the LED, which analyzed based on allocating the signal by transmitting to improve the quality was about how researched. In addition, our proposed system is able to improve the performance of BER and satisfied the Qos to desire users.

• Journal of KIISE:Information Networking
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• v.37 no.5
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• pp.317-326
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• 2010

Nowadays, transmission bandwidth for network traffic is increasing and the type is varied such as peer-to-peer (PZP), real-time video, and so on, because distributed computing environment is spread and various network-based applications are developed. However, as PZP traffic occupies much volume among Internet backbone traffics, transmission bandwidth and quality of service(QoS) of other network applications such as web, ftp, and real-time video cannot be guaranteed. In previous research, the port-based technique which checks well-known port number and the Deep Packet Inspection(DPI) technique which checks the payload of packets were suggested for solving the problem of the P2P traffics, however there were difficulties to apply those methods to detection of P2P traffics because P2P applications are not used well-known port number and payload of packets may be encrypted. A proposed algorithm for identifying P2P heavy traffics based on flow transport parameters and behavioral characteristics can solve the problem of the port-based technique and the DPI technique. The focus of this paper is to identify P2P heavy traffic flows rather than all P2P traffics. P2P traffics are consist of two steps i)searching the opposite peer which have some contents ii) downloading the contents from one or more peers. We define P2P flow patterns on these P2P applications' features and then implement the system to classify P2P heavy traffics.

• Journal of KIISE:Computing Practices and Letters
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• v.8 no.1
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• pp.71-81
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• 2002

The lack of specialties of the existing commercial web search systems stems from the fact that they have no capabilities to extract and gather the meaningful information from each information domain they cover. We are sure, however, that the necessity for the information integration system, not just search system, will be likely to become larger in the future. In this paper, we propose a design and implementation of an information integration system called TIC(target information collector). TIC is able to extract meaningful information from a specific information area in the internet and integrate them for the commercial service. We also show the evaluation results of our implementation. For the experiments we applied our TIC to the international procurement information area. The international procurement information is publicly and freely announced by each government to the world. To automatically extract common properties from the related source sites, we adopt information pointing technique using inter-HTML tag pattern parsing. And through the information integration framework design, we can easily implement a site-specific information integration engine. By running our TIC for about 8 months, we find out it can remove considerable amount of the duplicated information, and as a result, we can obtain high quality international procurement information. The main contribution of this paper is to present a framework design and it's implementation for extracting the information of a specific area and then integrating them into a meaningful one.

• The Journal of Engineering Research
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• v.5 no.1
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• pp.17-35
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• 2004

Svg(Scalable Vector Graphics) is xml graphic standard recommended by E3C as a language based on xml to express two-dimension graphic. Svg can accommodate all Xml's patency and advantage of interoperability, and can used as various web applications being combined with other xml language. In addition, Svg can be applied to the fields of electronic commerce, geographical information, computer education and advertisement because it can produce high quality of dynamic from real-time data. SVG's application can be enhanced by linking with database. In this paper, we discuss how Svg can be utilized in theater reservation system, not just explaining svg's meaning or ability. Svg added graphic advantage in addition to xml's advantage. This means that svg retains not only graphic element but also xml's softness. It becomes easier to designate seats and add them. Current reservation system provided in general only information on time and price for a ticket, but the system using SVG in this paper provides additional information on position, price, cancellation and purchase availability of seat.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.1
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• pp.113-119
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• 2013

Despite rapid changes in the structure of industry, manufacturing remains a key industry for economic progress, promotion of trade, increased employment, and the creation of new industries. Production technologies are essential for strengthening the competitiveness of small- and medium-sized manufacturing industries. However, it is very difficult to standardize and systematically propagate production technology from an experienced worker to an inexperienced worker because these technologies are generally improved by the skilled people in a workshop. In this study, we introduce a Web-based platform system consisting of a knowledge authoring tool, technology database, semantic database, and Web portal service for sharing production technologies for the exterior housing parts of mobile products. By investigating various cellular phone designs, reference form factors for three types of mobile phone housings were designed based on the standard features. In addition, several manufacturing technologies and considerable information such as reference mold designs and molding conditions optimized using CAE and recent R&D outputs are stored in this system.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.123-131
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• 2016

Process mining in big data environment utilize a number of data were generated from the business process. It generates lots of knowledge and insights regarding implementation and improvement of the process through the event log of the company's enterprise resource planning (ERP) system. In recent years, various research activities engaged with the audit work of company organizations are trying actively by using the maximum strength of the mining process. However, domestic studies on applicable sales auditing system for the process mining are insufficient under big data environment. Therefore, we propose process-mining methods that can be optimally applied to online and traditional auditing system. In advance, we propose continuous monitoring information system that can early detect and prevent the risk under the big data environment by monitoring risk factors in the organizations of enterprise. The scope of the research of this paper is to design a pre-verification system for risk factor via practical examples in sales auditing. Furthermore, realizations of preventive audit, continuous monitoring for high risk, reduction of fraud, and timely action for violation of rules are enhanced by proposed sales auditing system. According to the simulation results, avoidance of financial risks, reduction of audit period, and improvement of audit quality are represented.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.1
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• pp.73-83
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• 2008

For spatial analysis and decision-making based on territorial and urban information, technologies on 3D GIS with digital image data and photo-realistic 3D image models to visualize 3D modeling are being rapidly developed. Currently, satellite images, aerial images and aerial LiDAR data are mostly used to build 3D models and textures from oblique aerial photographs or terrestrial photographs are used to create 3D image models. However, we are in need of quality 3D image models as current models cannot express topographic and features most elaborately and realistically. Thus, this study analyzed techniques to use aerial photographs, aerial LiDAR, terrestrial photographs and terrestrial LiDAR to create a 3D image model with artificial features and special topographic that emphasize spatial accuracy, delicate depiction and photo-realistic imaging. A 3D image model with spatial accuracy and photographic texture was built to be served via 3D image map services systems on the Internet. As it was necessary to consider intended use and display scale when building 3D image models, in this study, we applied the concept of LoD(Level of Detail) to define 3D image model of buildings in five levels and established the models by following the levels.

• Journal of the Korean Society of Food Culture
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• v.15 no.2
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• pp.79-94
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• 2000

The purposes of this study were to : (a) analyze university students' perception and patronage behaviors to the service quality dimensions, and (b) assist university residence hall foodservices in formulating improved managerial strategies. Questionnaires were hand delivered and mailed to 1,210 university students residing in the residence hall and 13 foodservice managers. A total of 1,011 was usable; resulting in 83.6% response rate. The survey was conducted between October, 1998 and May, 1999. Statistical data analysis was completed using the SAS/Win 6.12 for Descriptive Analysis, $x^2-test$, T-test, ANOVA, and Stepwise Multiple Regression. Forty-seven percent of the respondents indicated that 'taste' was their first priority when choosing a menu. The reasons behind choosing residence hall foodservice were 'location', 'board plan', 'price', 'taste', 'opening hours', and 'menu variety'. The main reasons of dissatisfaction with the residence hall foodservice were 'board plan', 'taste', 'menu variety'. The overall satisfaction score was 2.99 out of 5. The satisfaction score of ${\ulcorner}convenience{\lrcorner}$, ${\ulcorner}food\;quality{\lrcorner}$ and ${\ulcorner}menu\;variety{\lrcorner}$were 3.25, 2.94 and 2.76, respectively. Generally, male students were more satisfied than females. Graduate students and students living in residence halls over six semesters were the most dissatisfied with the residence hall foodservice. Residence hall students were dissatisfied with the variables ${\ulcorner}menu\;variety{\lrcorner}$ and ${\ulcorner}facilities{\lrcorner}$in 'self-operated' operations, whereas ${\ulcorner}food\;quality{\lrcorner}$, ${\ulcorner}menu\;variety{\lrcorner}$ and ${\ulcorner}price{\lrcorner}$ in 'contracted' operations. Foodservice operations with 'less than 1,000 meals serving per day' was the highest satisfaction score(3.36) among other serving sizes. Meal price with 'less than 1,300 won' was most satisfied with students. When overall customer satisfaction and service quality dimensions were analyzed by Stepwise Multiple Regression ${\ulcorner}food\;quality{\lrcorner}$(p<.001), ${\ulcorner}price{\lrcorner}$(p<.001), ${\ulcorner}facilities{\lrcorner}$(p<.001), ${\ulcorner}convenience{\lrcorner}$(p<.001), ${\ulcorner}menu\;variety{\lrcorner}$(p<.001), ${\ulcorner}manager's\;attitude{\lrcorner}$(p<.0l), and ${\ulcorner}atmosphere{\lrcorner}$(p<.01), in decreasing order, significantly impacted on ${\ulcorner}overall\;customer\;satisfaction{\lrcorner}$.