• Proceedings of the IEEK Conference
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• 2001.06c
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• pp.209-212
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• 2001

In this paper, an intelligent notification system has been presented. The system operates on both wired and wireless internet. When a new message has been uploaded in a bulletin board systems(BBS) on HTTP web server, it sends the same message to their cellular phones of all members of a given group at the same time via SMS(Short Message Service). In addition, on reading SMS message, those who read them respond to a WAP server using pulling technique via wireless internet. Therefore, the HTTP server does know the members who did not read the message yet. Two different web servers, the HTTP server and the WAP server, running on a single system has been implemented. They share the single database which covers al1 related information about the BBS. The set of experiments shows that the notification system works well as we have expected Thus, we conclude that the proposed system that operates on both wired and wireless internet is the one of successful model for such environments.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1059-1062
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• 2005

A hybrid ad-hoc network consists of a wired network and a mobile ad-hoc network connected by the internet gateway. To provide seamless service for internet user in hybrid ad-hoc network, an efficient internet gateway selection technique and a fast handover technique are needed. In this paper, we propose a seamless handoff technique for providing mobility of mobile hosts in hybrid ad-hoc networks. The proposed technique improves general handoff performance by an internet gateway re-registration algorithm for ad-hoc networks. Moreover, it reduces handoff processing time in the range of certain region by using mobility management agent (MMA) and also the packet loss when handoff occurs out of the range of MMA by tunneling technique.

• Transactions of Materials Processing
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• v.12 no.2
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• pp.110-115
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• 2003

This paper is concerned with the compression test and forming process of flange by using virtual reality and analysis(simulation) program. This virtual manufacturing can be carried out one personal computer without any expensive devices for experiment. The virtual manufacturing composed of three modules such as the imput, calculation and the output modules on internet. Internet user can give the material's property and process parameters to the sever computer at the input module. On the calculation module, a simulator computes the virtual manufacturing process by analysis program and stores the data as a file. The output module is the program in which internet user can confirm virtual manufacturing results by showing tables, graphs, and 3D animation. This programs is designed by an internet language such as HTML, CGI, VRML and JAVA ,while analysis programs use the finite increasing, the virtual manufacturing technique will substitute many real experiments in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.892-905
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• 2018

In smart home environment, certificate based signature technology is being studied by communication with Internet of Things(IoT) device. However, block - chain technology has attracted much attention because of the problems such as single - point error and management overhead of the trust server. Among them, Keyless Signature Infrastructure(KSI) provides integrity by configuring user authentication and global timestamp of distributed server into block chain by using hash-based one-time key. In this paper, we provide confidentiality by applying group key and key management based on multi - solution chain. In addition, we propose a smart home environment that can reduce the storage space by using Extended Merkle Tree and secure and efficient KSI-based authentication and communication with enhanced security strength.

• English Language & Literature Teaching
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• v.10 no.1
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• pp.53-76
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• 2004

This paper introduces a class model based on a course, Internet English, offered by an English department at a university. The course has dual purposes of developing students I English skills and Internet using skills at the same time. In support of using the Internet for language learning, the advantages of project-based language learning and constructivist learning in relation to CALL are explored. The activities in this course, which are basically project-based under the paradigm of constructivist learning perspective, are explained in detail to show the relationship between second language learning theory and teaching application. The way how the four language skills - speaking, listening, reading, and writing - are integrated in this class is described as well. Finally, judgmental evaluation of the course by the students is noted. The results show that a project-based CALL class could be a promising class model to realize an integrative, constructivist, and authentic learning.

• Journal of Internet Computing and Services
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• v.5 no.1
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• pp.59-66
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• 2004

Symmetry region searching can extract face region without a prior information in an image by using symmetric. However, this method requires a plenty of the computation time because the mask size to process symmetry region searching must be larger than the size of object such as eye, nose and mouth in face. in this paper, it proposed symmetric by using symmetry region searching and Wavelet Transform to reduce computation time of symmetry region searching, and It was applied to this method in an original image. To extract exact face region, we also experimented face region searching by using domain division in extraction region.

• Journal of Internet of Things and Convergence
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• v.10 no.2
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• pp.103-108
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• 2024

In this paper, a smart elevator system was studied using real-time object detection technology based on YOLO(You only look once)v5. When an external elevator button is pressed, the YOLOv5 model analyzes the camera video to determine whether there are people waiting, and if it determines that there are no people waiting, the button is automatically canceled. The study introduces an effective method of implementing object detection and communication technology through YOLOv5 and MQTT (Message Queuing Telemetry Transport) used in the Internet of Things. And using this, we implemented a smart elevator system that determines in real time whether there are people waiting. The proposed system can play the role of CCTV (closed-circuit television) while reducing unnecessary power consumption. Therefore, the proposed smart elevator system is expected to contribute to safety and security issues.

• Journal of Internet of Things and Convergence
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• v.6 no.1
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• pp.73-81
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• 2020

The internet of things (IoT) using cloud computing is applied to nuclear industry in which the nuclear power plant (NPP) accident is analyzed for the safety assessment. The Fukushima NPP accident is modeled for the accident simulations where the earthquake induced plant failure accident is used for analyzing the cloud computing technology. The fast and reasonable treatment in the natural disaster was needed in the case of the Fukushima. The real time safety assessment (RTSA) and the Monte-Carlo real time assessment (MCRTA) are constructed. This cloud computing could give the practicable method to prepare for the future similar accident.

• Journal of the Korean Home Economics Association
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• v.40 no.6
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• pp.69-83
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• 2002

This study examined the effects of demographic variables on buying behavior, and investigated buyers'perceived value and risk perception of the internet shopping mall. The sample was collected by a department store in Daegu, and it included 1,732 individuals using the Cyber Mall. Research methods used in this study were simple statistics, t-test and ANOVA. The buyers perceived values through the internet shopping mall were classified into five categories-price, time, convenience, intrinsic attributes, reliability and the risk perception also was classified such as the overall purchasing process, quality of products, exposure of the personal information, delivery system, refund and exchange. The major findings of this study were 1) most important categories affecting their buying behavior were the value of convenience and following values in order were time, price, reliability, intrinsic attributes. 2) the risk perception were overall purchasing behavior, quality of products, exposure of personal information, delivery, and refund & exchange in order. 3) age of buyers, buying experience on the internet shopping mall, and gender were the important factors affecting the buyers'perceived value and risk. 4) the study also, showed that according to the variety of products, buyers perceived the value and risk differently, for example, the price was the most important perceived value in case of food product. The implication of the study is to strategically suggest how to enhance the buyers'perceived value and diminish perceived risk of different products.

• Korean Management Science Review
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• v.20 no.1
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• pp.89-102
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• 2003

With the progress of Internet and e-commerce, there have been many researches on the market efficiency of the Internet markets using real price data. Contrary to the common expectations by many economists, most of the previous researches have fatted to prove that the Internet market is more efficient than the conventional market. This paper empirically analyzes the pricing behavior of Internet and conventional retailers in South Korea. We have collected real price data on CDs and TVs from various types of retailers, from which we have analyzed three aspects of pricing behavior : price level, price change over time, and price dispersion across the retailers. We have found that the average prices of CDs and TVs at the Internet retailers are lower than those at the conventional retailers. We have also found that there is a close association between the behaviors (e.g., magnitude and timing of changes) of TV prices at the Internet retailers and those at the conventional retailers. It has been observed that the range of the CD prices at the internet retailers is less than a half of the range at the conventional retailers, which can be considered as an evidence of a relatively stronger price competition at the Internet market compared with the conventional market.