• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.292-295
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• 2008

We propose a PON repeater system which transports multiple PON channels at the same time over the physical limit of the standard E-PON reach. To increase the physical reach up to 60km, we used the O-E-O (optic-electric-optic) signal regeneration on an active remote terminal which is placed between a central office and passive remote nodes. Also, by incorporating the well-established WDM technology to aggregate multiple E-PON channels, we successfully increased the split ratio (the number of subscribers per fiber core) to over 256.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.88-88
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• 2002

Satellite Image archiving system requires large storage and long transmission time. A simple and cheap way of overcoming these limitations is to increase the compression ratio. However this requires a feasibility study for accurate applications. Here, a new still image compression standard is being developed, the JPEG2000. It provides lossless and lossy compression, progressive transmission by pixel accuracy and by resolution, region-of-interest coding, user-defined tiling size, random codestream access and processing etc. In this study, we will briefly introduce the JPEG2000 compression standard which provides a new compression technique based on the wavelet technology and offers better compression ratios, and evaluate the compression ratios of JPEG2000 for satellite image by performing various image quality tests. Also, we will compare brief test result using the commercial remote sensing software.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.12
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• pp.2330-2336
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• 2008

This paper deals with monitoring sensor robot control system for the application of wireless sensor network. In order to control the direction and speed of robot via remote sensing environment, low power, low weight sensors with ad-hoc networking between robots' sensors have been used. These wireless sensor network based robot monitoring system can be used for remote observation and detection of robots in the areas such as factories, power plants and other dangerous areas which are difficult for human access.

• Korean Journal of Remote Sensing
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• v.2 no.2
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• pp.107-116
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• 1986

A unique approach to access Landsat satellite imagery has been implemented on IBM PC microcomputer in order to generate image maps to be used as a substitute and/or supplement for a conventional topographic map. This method enables user to automatically: o extract a nominal image map, o geoencode or calibrate as an image map, and o create a multitemporal image file using CCTs containing precision processed Landsat MSS and TM images. These map extraction process includes: o location of map area in the selected CCT, o conversion of map coordinates to image coordinates, o extraction of map area, and o rotation of image to the true North/South and East/Weat direction.

• Journal of information and communication convergence engineering
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• v.20 no.1
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• pp.16-21
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• 2022

In this research, we create a network infrastructure based on a service-oriented infrastructure (SOI) for the virtualization technology and integrate it with a cloud technology that applies the cloud integration management platform (CIMP) concept. In CIMP, the server and storage will be separated. The server will be adopted for virtualization while the storage will be used by students and teachers to store data. As long they save their data in the storage module, every time, everywhere, and on every device, they can access their data. This research will implement the design of the network infrastructure and be applied to the remote practical learning system in the laboratory. Students and teachers will ultimately adopt this network infrastructure for remote practice using their respective devices without physically meeting in the laboratory. In the future, if the implementation phase is successful, then in addition to laboratory environments, it can be implemented in all learning activities at our campus.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.441-443
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• 2004

With the rapid development of the Internet over the recent years, in conjunction with the transmission protocol TCP/IP and the latest version of hypertext(HTML) facilities, new opportunities have come into existence for the use of the network for the remote control of experiments and the other practical systems in engineering education. Using graphical software environments in client-server systems, remote control and monitoring system can be easily designed. Client-server systems have some general advantages when compared with simple Remote-Access Systems. In this paper we present a client-server architecture for the distributed measurement system of instrumentation over the Internet. The proposed solution allows multi-user, multi-instruments sessions to be obtained by means of a queuing process and provides instrument lock capability. Client applications can be easily developed by using conventional high-level programming languages or well-assessed virtual instrumentation frameworks.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.1
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• pp.41-46
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• 2008

Since embedded software is sensitive to the resources and environment of target system, it should be debugged in the same environment as actual target system. However, existing tools to debug embedded software, in which access to internal signal or resources is limited, are uneconomical. In the thesis, economical and practical JTAG Adapter that can use open GDB is suggested. It can remove existing limitations of environment implementation that have many difficulties in implementing an environment for remote debugging. Hence, the thesis provides economical interfacing environment that can debug ubiquitous embedded software inside remote system.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.3
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• pp.1742-1760
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• 2017

Recent evolution in the open access internet technology demands that the identifying information of a user must be protected. Authentication is a prerequisite to ensure the protection of user identification. To improve Qu et al.'s scheme for remote user authentication, a recent proposal has been published by Huang et al., which presents a key agreement protocol in combination with ECC. It has been claimed that Huang et al. proposal is more robust and provides improved security. However, in the light of our experiment, it has been observed that Huang et al.'s proposal is breakable in case of user impersonation. Moreover, this paper presents an improved scheme to overcome the limitations of Huang et al.'s scheme. Security of the proposed scheme is evaluated using the well-known random oracle model. In comparison with Huang et al.'s protocol, the proposed scheme is lightweight with improved security.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.65-67
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• 2001

PLC (Power Line Communication) is the communication method using the existing power line installed in houses and offices to convert and transmit high frequency communication signal from tens of KHz to tens of MHz, and receive the filtered signal using high frequency filter. The advantage of PLC is that PLC uses the existing power line installed in houses and offices so it does not require separate power line. Easy and convenient access using electric outlets is another advantage of PLC. However, PLC has some disadvantages such as limited transmission power, high load interference and noise, variable signal attenuation, characteristic of impedance selective possibility of frequency property. This study designed the boiler temperature control system by unit using the modem designed on the basis of technology used for PLC modem, and designed remote control system using internet. After conducting experiments with those two systems, it was possible to control stably. By commercializing this product, we can avoid unnecessary heating of separate temperature control unit, and save the cost according1y, and it is possible to control on a remote site using internet in a more convenient way.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1039-1044
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• 2005

A Multi-channel serial device using the embedded Linux system is designed for a remote controlling and monitoring system. The proposed device consists of a FIFO, a state machine, and an interrupter. The device program written in embedded Linux enables the effective programming of device. While the conventional multi-channel serial devices accesses every individual serial devices, the proposed device accesses the multi-channel serial device as if it is a single serial device. The device efficiently performs the multi-channel serial input/output operation and has fast access time than the conventional multi-channel serial device.