• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1817-1818
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• 2006

In present, most of metallic structures (gas pipeline, oil pipeline, water pipeline, etc) are running parallel with subway in Seoul and Pusan.In this case, subway system make a stray current due to electrical corrosion on metallic structures. The owner of metallic structures has a burden of responsibility for the protection of corrosion and the prevention against big accident such as gas explosion or soil pollution and so on. So, they have to measure and analyze the data about P/S(Pipe to Soil) potential, amplitude of stray current, point of source of stray current and so on. In this paper, results of development about Wireless Remote Monitoring and Control System on Underground Pipeline in Stray Current Conditions are presented. And also field test data should be reporting.

• Journal of the Korean Data and Information Science Society
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• v.18 no.1
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• pp.161-174
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• 2007

In this paper, we propose a high performance database cluster system called HyperDB to process OLAP queries efficiently. HyperDB is a virtual database system running on top of internet-connected PCs; the PCs are used for their own purpose at ordinary times, but they are able to participate in the database cluster system at non-office hours. We propose fully logical replication technique and optimal parallel intra-query routing technique for extensibility and performance. Experiment for TPC-R benchmark shows significant performance upgrade compared with conventional approaches.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.2
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• pp.166-177
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• 1997

The prime mover performance of on - board Diesel Generator is well characterized by the variation of frequency and the load sharing on parallel running under electric load change. This study is aimed to configure the modeling for performance simulation regarding to DG operation which could be interested for education purpose or system analysis. The modeling had been made on the base of modules such as govenor, prime mover of diesel engine and generator with electric load system, which were then intergrated for total simula¬tion performance. One real model system has been introduced for deciding relating parameters and for the comparison of resulting performance in simulation. The responses from the modelling were confirmed in single and paralell operation, the results of which showed resonable accordance with the real system.

• Proceedings of the IEEK Conference
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• 1999.11a
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• pp.421-425
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• 1999

As the market size of multiprocessor systems for commercial applications, parallel systems, especially cache-coherent shared-memory multiprocessors that are conventionally designed for scientific applications need to be tuned in different fashion to achieve the best performance for new application area. In this paper, indepth investigation on the memory behavior which is the primary cause for performance changes were made. We chose representative benchmarks in scientific and commercial application areas. After running execution-driven simulation for bus-based cache-coherent shared-memory multiprocessors, we experienced significant differences and conclude that the systems must be carefully and differently designed to achieve the best performance when they are built for distinct applications.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.636-651
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• 2000

In these days, SNCF replace the connector wire (M-T type) with a dropper has a equivalent role and function of the one in general lines of TGV, and change the connector wire (T-T-M-M-T-T, T-T-M-M-T type, etc) into a New one has more flexible cable in parallel lines (air section air joint, etc) of TGV. The Connector wire has many problems according to a flow of excessive circulation current (or traction current) and a sudden rise of temperature on catenary when electric locomotive is running in high speed. To solve the question at issue of the connector wire in high speed railway catenary system of Fiance, SNCF return their operating experience in TGV lines to design and execution of catenary system Therefore, we have to deal with the question in design and execution of catenary system for kyoungbu HSR line because we will spend a lot of time and more money for maintenance than for construction of that.

• Journal of the Korean Society of Industry Convergence
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• v.7 no.2
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• pp.207-213
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• 2004

This paper describes the development of Behind-Tape-Reader (BTR) type DNC system using CYBER 180-830 as a central computer and IBM PC-AT cell control computer and NC lathe with FANUC 5T NC controller. In this system, the connection between central computer and cell control computer is done via RS-232C serial interface board, and that between cell control computer and FANUC 5T controller is done via parallel interface board. The software consists of two module, central computer communication module for NC program downloading and status uploading, NC machine running module for NC operating.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2002.08a
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• pp.208-211
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• 2002

The Kyunggi Bay (125-l28E, 36-38N) is a macro-tidal bay in the western central port of Korean Peninsula(Fig. 1). The Bay characterizes its feature as wide tidal flats, deep tidal channels and tidal sand ridges running in parallel to tidal flows. The macro-tidal range (up to approximately 8.6m) and consequent strong tidal currents erode the bottom sediment and selectively transport to the low-energy area forming tidal ridges or tidal flats. (omitted)

• Proceedings of the KIEE Conference
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• 2001.07a
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• pp.356-358
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• 2001

In general, when power lines, D/L and T/L are running parallel with bridge of metallic structure or crossing each other, AC corrosion is occur due to AC interference. This paper presents the results of AC interference mechanism, decision criteria of AC interference, and AC corrosion effects by analysis of AC induction voltage on pier and abut of bridge.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.5
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• pp.777-785
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• 1987

In this paper, a tightly-coupled multiprocessor system is implemented with four processing elements based on MC68000 CPU, a common menory (128KB), and a single time-shared bus. The multi-tasking operating system, MTOS, is modified so that the multiprocessor system can support multitasking and multiprocessing. The performance of the proposed system is evaluated by stochastic Petri Net system modeling. The efficiency and the processing power are simulated for various load factors and up to 16 PEs. By running benchmark programs, such as quicksort, FFT, and matrix-multiplication, the speed of parallel processing is compared with that of a single processor.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.6
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• pp.22-27
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• 1997

This paper propose a novel VLSI architecture for a multiplierless FIR filter chip providing variable-length taps. To change the number of taps, we propose two special features called a data-reuse structure and a recurrent-coefficient scheme. These features consist of several MUXs and registers and reduce the number of gates over 20% compared with existing chips using an address generation unit and a modulo unit. Since multipliers occupy large VLSI area, a multiplierless filter chip meeting real-time requirement can save large area. We propose a modified bit-serial multiplication algorithm to compute two partial products in parallel, and thus, the proposed filter is twice faster and has smaller hardware than previous multiplierless filters. We developed VHDL models and performed logic synthesis using the 0.8.mu.m SOG (sea-of-gate) cell library. The chip has only 9,507 gates, was fabricated, and is running at 77MHz.