• Korean Journal of Remote Sensing
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• v.18 no.3
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• pp.147-153
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• 2002

The real-time reception and recording of down-link mission data from a satellite requires the highest reliability because the data lost in receiving process cannot be recovered. The data receiving and recording system has moved from a set of dedicated hardware and software components to commercial-off-the-shelf (COTS) components in order to reduce the system cost as well as to upgrade the system easily for handling other satellite data. The use of COTS hardware and middleware components prevents the system developer from correcting or modifying the internal operations of the COTS components, and hence, instant performance degradation of the COTS components which affects the reliable data acquisition must be covered by a software algorithm. This paper introduces the instant performance problem of a COTS data recording device which leads to the data loss in the real-time data reception and recording process. As a result, the requirement of the modification of the conventional data read/write technique is issued. In order to overcome the data loss problem due to the use of COTS components and the conventional software technique, a new algorithm called a software buffering technique is proposed. The experiments show that the application of the proposed technique results in reliable real-time reception and recording of high speed serial data.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.15-18
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• 1998

Most existing FRADs support only permanent virtual circuit-based frame relay services. But several applications such as intranets, desktop video conferencing, remote access and voice applications typically do not require the dedicated bandwidth capabilities of PVCs because connections are only occasionally needed. So it drives the need of switched virtual circuit-based FRADs which offer potentail cost savings associated with dynamic bandwidth on demand connectivity. In this paper, we describe Frame Relay Network Access System(FNAS) that provides switched virtual circuit-based frame relay access for dial-up Internet services. The hardware configuration, software architecture and call processing flow of FNAS is explained.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.1
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• pp.27-33
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• 1997

This project is dedicated to the elaboration of a man-machine system for monitoring the non spread of nuclear weapons, technologies, raw materials. The main purpose of such a system depends on the customer requirements and may be : - control of non proliferation of nuclear technologies, especially those that can be used to manufacture a nuclear explosive device; - the appraisal of the possibility of production of nuclear weapons by a certain country on the basic of its intellectual and scientific-technical potential, its raw material resources, its export-import potential and other parameters.

• Convergence Security Journal
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• v.3 no.3
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• pp.35-42
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• 2003

With the rapid adaption of the network technologies, there has been in continual troubles with network attacking and computer virus which are getting more automatic and intelligent. To solve them, we survey the existing and currently used security solutions, describe the architecture of traditional network management, and propose the model of a MIB-based security management system which has dedicated management information base on each security solution.

• Journal of Broadcast Engineering
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• v.1 no.2
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• pp.133-141
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• 1996

In this paper, a VOD(Video -on-Demand) system is implemented using LAN(Local Area Network). The use of LAN causes the time-delay problem due to its narrow channel limitation, as a result, the service using the conventional LAN used not to be popular. In this paper, to solve these problems, we develop the modified topology, the selection methodology of the network equipment, and the dedicated(improved) protocol. Consequently, we can serve at most 3 or 4 clients at the same time, and we conclude it is necessary to optimize the network buffer size depending on the size of video data.

• Journal of Electrical Engineering and Technology
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• v.2 no.4
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• pp.505-512
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• 2007

The object of this paper is to study a new control structure for sensorless induction machines dedicated to electrical drives using a three-level voltage source inverter VSI-NPC. The amplitude and the rotating speed of the flux vector can be controlled freely. The scheme investigated is an Enhanced direct torque control "EDTC" for electric vehicle propulsion. The considered application imposes some constraints which are achieved in EDTC control (fast torque response, optimal switching logic, torque control at zero speed, and large speed control. The results obtained for an induction motor indicate superior performance over the FOC type without need for any mechanical sensor.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.813-816
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• 2009

A commercial-scale RDF boiler that its burning capacity is 400 kg-RDF/hr and steam production capacity is 2 ton/hr. It has a chain type stoker and waste heat recovery system. Heat exchanger is vertical water-pipe so that soot blowing and removal is convenient during operation. Dry scrubber, bag filter and activated carbon tower have been installed for the reduction of air pollutant gases and dust. Analysing data of pollutants from stack such as $SO_x$. $NO_x$ and dioxin shows so good results that the boiler system could comply the regulated emission limits.

• Management Science and Financial Engineering
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• v.6 no.2
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• pp.47-67
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• 2000

It is discussed how to assign delivery tasks to automated guided vehicles (AGVs) for multiple container cranes in automated container terminals. The primary goal of dispatching AGVs is to complete all the lading and discharging operations as early as possible, and the secondary goal is to minimize the total travel distance of AGVs. It is assumed that AGVs are not dedicated to a specific container crane but shared among multiple cranes. A mathematical formulation is developed and a heuristic algorithm is suggested to obtain a near optimal solution with a reasonable amount of computational time. The single-cycle and the dual-cycle operations in both the seaside and the landside operations are analyzed. The effects of pooling AGVs for multiple container cranes on the performance of an entire AGV system are also analyze through a numerical experiment.

• Journal of Multimedia Information System
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• v.5 no.3
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• pp.155-162
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• 2018

Nowadays, the tracking technology of Quadrant Detector will become actual by new micro devices. Based on the past filed data of the reception experiment with COMETS satellite, we have studied on new device (AD8302, phase difference detector) was acquired and suspect its abilities. In 1998, we have developed a Quadrant Detector for mobile to track a weak signal from satellite on Ka band of COMETS. The Quadrant Detector is comprised of four dedicated feed components for reception under an environment of Nakagami - Rician fading, and one transmission and reception feed component. We were successful in receiving a 23 GHz beacon signal from ICE transponder of the COMETS and succeeded in tracking the satellite from a moving vehicle at speeds of approximately 10 ~ 20 Km/h on paved roads. In 2018, with new device AD8302, we have verified new QD system and performed a simulation, based on the past filed experiment. This new device shall be improving the tracking abilities from mobile body on the earth to the multimedia satellite.

• Journal of the Semiconductor & Display Technology
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• v.2 no.3
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• pp.13-18
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• 2003

A remote monitoring system of the semiconductor equipment is used to monitor or control operations of the equipment. Most of the conventional monitoring systems are based on the client-server model with the general purpose PC. Basically, it implies the difficulties in the system reliability and cost down due to its size and complexity. To overcome these difficulties, we suggest an embedded web server which is based on the low-cost microprocessor. It is designed for the monitoring or controlling a dedicated equipment only. To evaluate the feasibility of the suggested embedded web server, we have implemented a test-board with ATMega103 and programmed the basic modules using the AVR-GCC. Finally, we have tested its operations on the MS Explorer 6.0 environment.