• Proceedings of the KIEE Conference
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• 2001.04a
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• pp.215-217
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• 2001

This paper describes an all solid-state switch pulse generator for various applications where square pulse voltage is required. The pulse generator produces various voltage pulses: voltage $5{\sim}100kV$. current $10{\sim}200A$, pulse width $1{\sim}10{\mu}sec$, repetition rate up to 500Hz. The output power is the combination of these parameters up to 10kW. It consists of a DC-DC converter and several pulse generating modules which are connected in series to obtain higher pulse voltage. Each module contains semiconductor switches (IGBT's), energy storage capacitors and control units to trigger switches. The structure and operational principle are described and the protection circuit for reliable operation is suggested. Experimental results show that the pulse generator can be used for applications with nonlinear loads.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.8
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• pp.643-649
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• 2016

This paper presents a new image cache algorithm for real-time implementation of high-resolution color image warping. The cache memory is divided into four cache memory modules for simultaneous readout of four input image pixels in consideration of the color filter array (CFA) pattern of an image sensor and CFA image warping. In addition, a pipeline structure from the cache memory to an interpolator is shown to guarantee the generation of an output image pixel at each system clock cycle. The proposed image cache algorithm is applied to an FPGA-based real-time color image warping, and experimental results are presented to show the validity of the proposed method.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.61-67
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• 2020

This paper is to propose a hybrid memory adaptor using next-generation nonvolatile memory devices such as phase-change memory to improve the performance limitations of OpenStack-based object storage systems. The proposed system aims to improve the performance of the account and container servers for object metadata management. For this, the proposed system consists of locality-based dynamic page buffer, write buffer, and nonvolatile memory modules. Experimental results show that the proposed system improves the hit rate by 5.5% compared to the conventional system.

• Transactions of Materials Processing
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• v.5 no.1
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• pp.61-71
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• 1996

A computer-aided process design system for axisymmetric deep drawing products has been developed. An approach to the system is based on the knowledge based system. Knowledges for the system are formulated from the plasticity theory handbooks experimental results and empirical knowhow of the field experts. the system is composed of four main modules such as geometrical design test & rectification and user modification. The input to the system is final sheet-metal object geometry and the output from the system is process sequence with intermedi-ate objects geometries and process parameters, such as drawing load blank holding force clearance cup-drawing coefficient.

• Journal of the Korean Solar Energy Society
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• v.26 no.1
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• pp.73-79
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• 2006

The integration of PV modules into building facades or roof could raise PV module temperature that results in the reduction of electrical power generation. Lowering operating temperature of PV module is important in this respect, and PV module temperature should be considered more accurately, for building-integrated PV(BIPV) systems in predicting their performance. This paper describes a BIPV solar roof design and verifies its performance through experiment In relation to the effect of ventilation in space between PV module and roof surface. The results showed that the ventilation in the space had a positive effect in lowering the module temperature of the BIPV solar roof that enhanced the performance of its electricity generation.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.4
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• pp.142-151
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• 1996

This paper presents a new symmetrical routing architecture for FPGA and an efficient routing algorithm for the architecture. The routing architecture adopts the segmented wires and the improved switch modules. Segmetned wires construct routing channels which pass through the chip in vertical and horizontal directions. To maximize the utility of a track, a track in each switch module can be separated in two part using a programmable switch to route two different net. The proposed routing algorithm finds all assignable tracks for a given net and selects the best track from assignable tracks to minimize the number of programmable switches and the unused portion of the wire segments. In order to stabilize the perfomrance of the algorithm, the routing order is defined by weighted sum of the number of wire segment, the length of wire segmetn, and the number of pin. Experimental results show that routability is improved dramatically and the number of crossing switches are reduced about 40% compared with the previous works.

• IEMEK Journal of Embedded Systems and Applications
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• v.13 no.2
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• pp.93-100
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• 2018

In this paper, we present a novel scheme of data transmission for logistics vehicles connected with 3G mobile communication networks. The proposed method enhances the efficiency of data transmission by varying the packet transmission period according to the vehicle speed and by reducing the amount of transmitted data using a reduced packet structure. The main contribution is to present the experimental verification in which the proposed method is applied to commercial logistics vehicles that operate with networked data transmission modules. Being compared with the existing method, the proposed scheme shows superior performance in terms of data reduction and transmission speed.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.177-185
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• 1997

The purpose of this study is to investigate the mechanical properties of super-workable concrete using O.P.C., blast-furnace slag, and fly ash respectively. For this purpose, after determining the optimum mix proportion of super-workable concrete according to unit weight of binder and percentage of fine aggregate respectively, mechanical properties of super-workable concrete such as compressive, tensile and flexural strength as well as elastic modules were tested and analyzed. Also, the mechanical performances of super-workable concrete were compared with those of high-strength concrete with equal mix proportion of concrete. As a result, super-workable concrete have an excellent mobility, placeability, and segregation-resistance, but the strength of super-workable concrete was shown to be somewhat lower than that of high-strength concrete with equal mix proportion of concrete.

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.2 s.17
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• pp.5-12
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• 2004

The erosion wear of gun barrel occurs due to heat and chemical reactions. The high pressure and temperature in chamber increase the erosion wear. It is known that the metal phase transfer is the primary wear factor in a gun barrel under high temperature. In this paper, the tool of wear prediction in high pressure gun tube has been developed. The program developed has three modules such as DIRECT(interior ballistics analysis module), INVERSE(gun design module), and WEAR(wear prediction module). The prediction of wear was compared with the experimental data which was collected in the field unit. The prediction results shows good trend with the collected data.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.2
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• pp.301-307
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• 2009

In the paralleled converter module with peak current mode control, current imbalance appears when the voltage controllers with integral control of converter module are not exactly identical. In this paper, the voltage controller is designed to equal the current command of each converter module using the current command bus. The current balance controller is also proposed to balance the average currents of converter modules with imbalaced inductance. It is designed to have good transient response. Proposed method is implemented with the paralleled 2-module and 4-module boost converters with imbalanced inductance. Experimental results verify the performance of current share during both steady and transient states of converter.