• ETRI Journal
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• v.38 no.1
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• pp.9-17
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• 2016

We demonstrate a time- and wavelength-division multiplexed passive optical network system employing a vertical-cavity surface-emitting laser array-based optical line terminal transceiver and a tunable bidirectional optical subassembly-based optical network terminal transceiver. A packet error-free operation is achieved after a 40 km single-mode fiber bidirectional transmission. We also discuss an arrayed waveguide grating, a photo detector array based on complementary metal-oxide-semiconductor photonics technologies, and low-cost key devices for deployment in access networks.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.149-154
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• 2003

As 21th century advances, internet order system had been developed to maintain convenience along with development of high speed internet networks. To meet the consumer's desire to use the internet food order system in any place and at ant time. we developed wire/wireless internet food order systems that uses the wireless internet terminals (PDA, Pocket PC, etc). This paper presents the design and implementation of the wireless internet food order system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.4
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• pp.1630-1642
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• 2016

Inter-domain routing is the most critical function of the Internet. The routing system is a logical network relying on the physical infrastructure with geographical characteristics. Nature disasters or disruptive accidents such as earthquakes, cable cuts and power outages could cause regional failures which fail down geographically co-located network nodes and links, therefore, affect the resilience of inter-domain routing system. This paper presents a model for regional failures in inter-domain routing system called REFER for the first time. Based on REFER, the resilience of the inter-domain routing system could be evaluated on a finer level of the Internet, considering different routing policies of intra-domain and inter-domain routing systems. Under this model, we perform simulations on an empirical topology of the Internet with geographical characteristics to simulate a regional failure locating at a city with important IXP (Internet eXchange Point). Results indicate that the Internet is robust under a city-level regional failure. The reachability is almost the same after the failure, and the reroutings occur at the edge of the Internet, hardly affecting the core of inter-domain routing system.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2001.11a
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• pp.318-321
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• 2001

We have designed an Internet voting system applicable for worldwide voting which is based on Ohkubo et. al,'s scheme[9] combined with Public Key Infrastructure (PKI). To the best of our knowledge, this is the first trial to serve secure Internet voting system to the world. In our system, voter's privacy is guaranteed by using blind signature and mix-net, and robustness is provided through the threshold encryption scheme. By employing Java technology, we propose a way of typical implementation for internet voting system. Furthermore, PKI permits worldwide key distribution and achieve “one certificate/one vote” policy. Therefore, anyone can participate in the voting if he gets a certificate from Certificate Authority (CA). By the joint work between Korean and Japanese teams, the implementation aims to select MVPs in 2002 FIFA World Cup Korea-Japan$\^$TM/ in easy and friendly manner for any Internet user to participate and enjoy Internet voting.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2115-2117
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• 2003

This paper is study on internet based wireless remote control and monitoring for the system to purify water. Environment of the water quality grew worse. Therefore we require the effective system to purify water. Now national internet based wireless remote control and monitoring make a sensation and are a problem to be solved. This paper demonstrate internet based wireless remote control and monitoring for the system to purify water. This system including on server and many client distributed in whole country. The server is collecting information from the client. This information is then written inside database. The database is dealing with website and server and client.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.301-304
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• 2003

Recently, the development of internet remote control system has been studied lively along with fast growth of internet. In this paper, we proposed the internet-based remote control and monitoring system using java platform. The apache web server that is now used worldwide was constructed for monitoring and controlling of an machine in administrator's web browser. We solved the limitation on security which is the biggest problem of internet control system due to strong security setting in web server. As a result of experiment which is used in the proposed remote internet control system, several time-delay occurred in internet. However, correct control result could be achieved without an error. And this system monitored informations of a RPM, temperature and the other condition in almost real time.

• Korean Journal of Computational Design and Engineering
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• v.6 no.2
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• pp.140-146
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• 2001

A nuclear Power Plant is composed of a number of mechanical components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to evaluate the integrity of these mechanical components, a lot of data are required including inspection data, geometrical data, material properties, etc. Therefore, an effective database system is essential to manage the integrity of nuclear power plant. For this purpose, an internet based virtual reality environment and web database system was proposed. The developed virtual reality environment provides realistic geometrical configurations of mechanical components using VRML (Virtual Reality Modeling Language). The virtual reality environment was linked with the web database, which can manage the required data for the integrity evaluation. The proposed system is able to share the information regarding the integrity evaluation through internet, and thus, will be suitable for an integrated system for the maintenance of mechanical components.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1409-1417
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• 2003

In the 21st century, the concept of remote design and manufacture is strongly required in manufacturing processes to reduce cost and time-to-market. The objective of this paper is the development of an internet-based dimensional verification system for reverse engineering. An inspection client can register measurement data at the developed web server. Collaborators related to the development of a new product can confirm geometrical form from measurement data, check dimensional information and mark up the important parts, as well as make a statement of their views through the Internet. The developed system is realized through the ActiveX-Server architecture. Functions of the dimensional verification module are constructed as ActiveX by using the visual C＋＋ and OpenGL. The usefulness of the developed system is confirmed through a case study.

• Proceedings of the Safety Management and Science Conference
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• 2002.11a
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• pp.157-163
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• 2002

Automated manufacturing systems are applied to shop floors as a tool for the increase of productivity and quality and the decrease of manufacturing lead times and industry accidents. One of the most important issue of the present day is the application of Internet. The development of Internet technologies makes manufacturing enterprises break spacial barriers between users and shop floors, and collect various field data in remote sites. In this research, an Internet-based remote control system for a small-sized automated storage and retrieval system is developed for the purpose of real-time monitoring and control of automatic production equipment. The developed system has a client-server architecture and transmits real-time images of the automated storage and retrieval system to a client by ar CCD camera connected to a server. Based on the transmitted images, the client sends commands to PLC of the server, and part storage and retrieval tasks are executed.

• Journal of the Korea Safety Management & Science
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• v.4 no.1
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• pp.57-68
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• 2002

As Internet spreads rapidly, the industrial structure is changing to a new paradigm. The previous EDI system was asked to change and WEB EDI, E-Mail EDI, FTP EDI etc. which are based on the internet appeared. These days the XML/EDI which has XML document appeared. The XML/EDI consider advantages and disadvantages of VAN/EDI and EDI which based on the internet. Also, EDI system has to assure a safe exchange between sender and receiver. But, the internet has security problems because it uses a open TCP/IP protocol. Although there are many methods for security, it is being studied with XML concept. On this paper, we will suppose the XML/EDI system model with XML Signature, and build a procedure of electronic signature and delivery of document between sender and receiver.