• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.10a
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• pp.370-373
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• 2008

Small size gas turbine disk requires good mechanical strength and creep properties at high temperature. In this study, Waspaloy was used as a superalloy to satisfy these specifications. The control of microstructure was needed to satisfy material properties at high temperature. In order to do this, we studied forging conditions and material analysis. Therefore die and preform design conducted so that hot forged gas turbine disk could have a good microstructure. The die and preform shapes are designed with consideration of the predefined hydraulic press capacity and the microstructure of forging product. Also we carried out the hot compression test for Waspaloy in various test conditions. From these results, we obtained the forging conditions as material temperature, die velocity etc. To verify these forging conditions, we conducted FE simulations by means of the DEFORM 2D-HT. In this study, the hot closed die and preform designs were completed to offer high temperature material properties of a small size gas turbine.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.865-870
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• 2009

In this study, the adequacy of Reynolds numbers and Froude numbers derived from about sixty domestic water treatment plants (WTPs) were analyzed in order to estimate the characteristics of hydraulic behavior within the rectangular shaped sedimentation basins used widely. From the results of analysis, most of domestic WTPs have satisfied the criteria regulated as that Reynolds number should less than 1,000(dimensionless). On the other hand, they have not been able to satisfy the Froude number criteria, which should be higher than $1.0{\times}10^{-6}$. The reasons why most of domestic WTPs could not satisfy the criteria are that its criteria basis has been not only inadequate, but also the concept of external flow occurred around a settling particle has been ignored. Accordingly, this study proved the feasibility of Archimedes number, which indicates the ratio between particle Reynolds number and Froude number, to evaluate the hydraulic efficiency and its function of scale factor.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.960-964
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• 2011

High speed railway structure, contact of vehicle needs to design considering the running stability(dynamic behavior). Also, upper structure has to satisfy design standard about moving load, high speed train(KTX). So, the high speed railway structure has to satisfy the requirement of natural frequency, vertical acceleration on deck, face distortion and vertical displacement considering ride comfort, which is suggested Ho-nam high speed railway design standard. In this study, it was investigated and evaluated to the dynamic behavior for tow plate Girder railway bridge subjected to moving load considering real high speed train loads.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2814-2820
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• 2011

Railway bridge, contact of vehicle needs to design considering the running safety about the running train load of the railway bridge, ride comfort and dynamic safety. Also, upper structure of the railway bridge has to satisfy design standard about moving load(train). So, the railway bridge has to satisfy the requirement for vertical acceleration of the bridge deck, vertical displacement of the bridge and face distortion, which is suggested railway design standard in Korea(2011.5.). In this study, it was investigated and evaluated to the running safety about the running train load of the railway bridge, ride comfort and dynamic safety with railway design standard for steel composite(Steel Box Girder) railway bridge considering KTX, freight train and standard train load.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.1027-1034
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• 2011

Electronic devices in railway vehicle perform various functions such as not only braking and propulsion but also monitoring of vehicle condition, on-line diagnosis, and passenger information service, etc. These devices, distributed in vehicle, should be efficiently connected so as to properly perform the functions. IEC (International Electro-Technical Commission) standardized train communication network (TCN) as IEC 61375-1, -2. TCN can reduce the interconnecting work load by reducing the number of wire-line, compared with existing hard-wire connection, and it brings the efficient control by enabling various devices to share the information. But existing TCN can not satisfy the increasing service demands like passenger internet access and CCTV surveillance, etc. In this paper, we investigate ECN (Ethernet Consist Network) and ETN (Ethernet Train Backbone) which are proposed to satisfy these demands and in the process of standardization by IEC TC9 WG43.

• ETRI Journal
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• v.30 no.1
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• pp.141-151
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• 2008

In this paper, we introduce a new verification platform with ARM- and DSP-based multiprocessor architecture. Its simple communication interface with a crossbar switch architecture is suitable for a heterogeneous multiprocessor platform. The platform is used to verify the function and performance of a DVB-T baseband receiver using hardware and software partitioning techniques with a seamless hardware/software co-verification tool. We present a dual-processor platform with an ARM926 and a Teak DSP, but it cannot satisfy the standard specification of EN 300 744 of DVB-T ETSI. Therefore, we propose a new multiprocessor strategy with an ARM926 and three Teak DSPs synchronized at 166 MHz to satisfy the required specification of DVB-T.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.237-242
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• 1999

In this study, a design method using plane actuator is developed to make new speaker system, whose shape is much thinner than that of conventional loudspeaker. Piezofilm(PVDF) is used as plane actuator of flat speaker. To avoid the distortion of sound radiated from flat speaker, the frequency response of radiated sound to be flat is taken as the design objective. The electrode pattern and orientation angle of piezofilm actuator is optimized to satisfy the design objective. The formulation is based on the coupled finite element and boundary element method. Genetic algorithm is used in the optimization process, which is useful in the optimization of discrete design variables. Frequency response with optimized piezofilm actuator is made flat enough to satisfy the design objective. For the enhancement of sound power, double-layered piezofilm actuators are also considered. The sound power with double-layered actuator becomes larger than that with single-layered actuator as expected.

• Kyungpook Mathematical Journal
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• v.60 no.2
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• pp.307-318
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• 2020

This article concerns the class of rings which satisfy the property of inserting regular elements at zero products, and rings with such property are called regular-IFP. We study the structure of regular-IFP rings in relation to various ring properties that play roles in noncommutative ring theory. We investigate conditions under which the regular-IFPness pass to polynomial rings, and equivalent conditions to the regular-IFPness.

• The Journal of Sustainable Design and Educational Environment Research
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• v.9 no.3
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• pp.59-67
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• 2010

Architectural design for school can be completed well when the environment-friendly elements are satisfied. In other words, the environment-freindly element could be most important idea for school planning, and one should have this direction for each element as a design goal. In this study, I defined the "environment-friendly" as the environment for nature and human. I examined what could satisfy those and would be its principles. I set up the criteria to satisfy each priciple. Most important factor to keep the relation between nature and human would be reducing carbon dioxide emissions, and a green belt would absorb it. Therefore, I think that there would be effective possibility when suitable conditions are applied in phases. Every school can have comfort as environment-friendly facility, at the same time, contribute to nature. Also, students can learn and study nature, and perform a duty as human.

• Proceedings of the Korea Database Society Conference
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• 1999.06a
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• pp.307-313
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• 1999

This paper reviews and assesses the analogy between the human immune system and network intrusion detection systems. The promising results from a growing number of proposed computer immune models for intrusion detection motivate this work. The paper begins by briefly introducing existing intrusion detection systems (IDS's). A set of general requirements for network-based IDS's and the design goals to satisfy these requirements are identified by a careful examination of the literature. An overview of the human immune system is presented and its salient features that can contribute to the design of competent network-based IDS's are analysed. The analysis shows that the coordinated actions of several sophisticated mechanisms of the human immune system satisfy all the identified design goals. Consequently, the paper concludes that the design of a novel network-based IDS based on the human immune system is promising for future network-based IDS's