• Title/Summary/Keyword: 실용재

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Characteristics of Remote Sensors on KOMPSAT-I (다목적 실용위성 1호 탑재 센서의 특성)

  • 조영민;백홍렬
    • Korean Journal of Remote Sensing
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    • v.12 no.1
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    • pp.1-16
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    • 1996
  • Korea Aerospace Research Institute(KARI) is developing a Korea Multi-Purpose Satellite I(KOMPSAT-I) which accommodates Electro-Optical Camera(EOC), Ocean Color Imager(OCI), Space Physics Sensor(SPS) for cartography, ocean color monitoring, and space environment monitoring respectively. The satellite has the weight of about 500 kg and is operated on the sun synchronized orbit with the altitude of 685km, the orbit period of 98 minutes, and the orbit revisit time of 28days. The satellite will be launched in the third quarter of 1999 and its lifetime is more than 3 years. EOC has cartography mission to provide images for the production of scale maps, including digital elevation models, of Korea from a remote earth view in the KOMPSAT orbit. EOC collects panchromatic imagery with the ground sample distance(GSD) of 6.6m and the swath width of 15km at nadir through the visible spectral band of 510-730 nm. EOC scans the ground track of 800km per orbit by push-broom and body pointed method. OCI mission is worldwide ocean color monitoring for the study of biological oceanography. OCI is a multispectral imager generating 6 color ocean images with and <1km GSD by whisk-broom scanning method. OCI is designed to provide on-orbit spectral band selectability in the spectral range from 400nm to 900nm. The color images are collected through 6 primary spectral bands centered at 443, 490, 510, 555, 670, 865nm or 6 spectral bands selected in the spectral range via ground commands after launch. SPS consists of High Energy Particle Detector(HEPD) and Ionosphere Measurement Sensor(IMS). HEPD has mission to characterize the low altitude high energy particle environment and to study the effects of radiation environment on microelectronics. IMS measures densities and temperature of electrons in the ionosphere and monitors the ionospheric irregularities in KOMPSAT orbit.

Analysis and Measurement of Residual Stress of Al 7175 Ring Rolls after Quenching and stress Relieving (고강도 알루미늄 7175 합금 링롤재의 급냉 및 응력제거처리후 잔류응력 유한요소해석 및 측정)

  • 박성한;구송회;이방업;은일상
    • Journal of the Korean Society of Propulsion Engineers
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    • v.1 no.1
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    • pp.104-110
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    • 1997
  • To predict the effect of ring expansion and ring compression on residual stress relief of Al 7175 ring rot]s, 2-D axisymmetric thermal analysis and elastoplastic analysis were performed. The residual stress distributions along the thickness of T73, T7351 and T7352 treated rings were measured using three step sectioning method. The measured results were compared to numerical ones for quenched and stress relieved rings. After quenching, calculated hoop and axial residual stresses were similar to measured ones for T73 treated rings. The residual stresses of T7351 and T7352 treated rings were decreased remarkably compared to T73 treated rings. The effect of axial residual stress relief was superior to that of hoop one, and also ring compression to ring expansion. It was concluded that ring compression is advantageous over ring expansion in view of stress relief effect and practicality, and vice versa in view of dimensional control and press power.

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Minimum Weight Design of Built-up T Based on HCSR (HCSR 기반 T형 조립부재의 최소중량설계)

  • Shin, Sang-Hoon;Ko, Dae-Eun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.6
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    • pp.389-394
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    • 2017
  • In a conventional ship structure, stiffeners with an asymmetric section, such as inverted angles, are used widely despite the disadvantage of strength compared to the stiffeners with a symmetric section, such as a built-up T. On the other hand, T-type built-up members are attracting more attention than L-type inverted angles due to the increased size of ships. The purpose of this study was to develop an optimal design program for a built-up T, and apply an evolution strategy as an optimization technique. In the optimization process, the gross thickness concept was adopted for the design variables and objective function, and the constraints are set up based on HCSR (Harmonized Common Structural Rules). Using the developed program in this study, the optimal stiffener design was carried out for 300K VLCC and 158K COT of which the orders were obtained lately. The optimal results revealed the weight reduction effect of 144 tons and 60 tons, respectively.

Design of Reassembly Unit Modular Wearable Device (단위 모듈 기반의 재조립 가능한 웨어러블 디바이스 구조 설계)

  • Lee, Geo-Yun;Kang, Soon-Ju
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.3
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    • pp.338-346
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    • 2016
  • Wearable Device has various constraint about battery power consumption, size, weight, etc, because the devices is worn and operated by person and provide services. So, if a device includes too many functions, it dose not satisfies the constraint and lose price competitiveness due to become expensive. Therefore we suggest that make reassembly Unit Modular Device witch has common used functions in wearable devices and user can receive various services to reassemble Unit Modules. It is comprised of frames and modules. Each module has various functions. Each frames help module to communicate each modules. To realize this device, we design to guarantee each services to use necessary modules, to give priority to modules depending on the important of the task, to set that does not use to low energy mode.

A Reuse Model Utilizing Diverse Aspects of Components and Services (컴포넌트의 다면성과 서비스를 기반으로 하는 재사용 모델)

  • Park, Soo-Jin;Park, Soo-Yong
    • Journal of KIISE:Software and Applications
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    • v.34 no.4
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    • pp.303-316
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    • 2007
  • Even though many approaches for reuse have been introduced, software engineers are still hesitating to reuse existing software components. Among various reasons for the phenomena, the most significant one is that existing approaches failed to give substantial benefit for the reduction of developers' effort in reusing software assets. To solve this problem, we introduce a custom reuse model utilizing diverse aspects of components specified by RAS and services oriented architecture. We also carried out a case study to demonstrate its feasibility and evaluated it by comparing it to an existing code-based software reuse process. The proposed reuse model helps in the reduction of effort in reusing existing components by decreasing the time for searching and understanding them. Compared to other approaches such as product line engineering, our approach for software reuse using MPC does not require much initial work for implementing the reuse model in different projects. It is of interest to software engineers who are worried about heavy investment, which can cause the delay in their usual development work. Furthermore, the proposed reuse model is not mutually exclusive with other approaches for software reuse such as CBSD or product line engineering. It can accelerate the benefits gained from them.

"의자의야(醫者意也)"에 관한 소고(小考)

  • Kim, Gi-Uk;Park, Hyeon-Guk
    • Journal of Korean Medical classics
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    • v.20 no.4
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    • pp.65-79
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    • 2007
  • 재한의학적착자상상견적"의자의야"저개어구(在한의學的着者上常見的"의者意也"저개語句), 파의학이론적신비성(把의學理論的神秘性), 치료방법적영활성(治료方法的영活性), 의가적오성간주'의'(의家的悟性看做'意'). 환구화래설(換句話래說), 한의학적운치포괄"가이의회(한의學的운致包括"可以意회), 난우언전"적감각(難于言전"的感覺). 수연의학기자연과학우실용기술(수然의學旣自然科學又실用技술), 환미비소우의가이'의'여하구축학문적연구(환未비소于의家以'意'如何구筑學問的硏究). 여금종각개각도평가전통과학기술화문화적시후(如今종各개角度評가전統科學技술和文化的시候), 서방과학기술재지구상번성이보급이후(西方科學技술在地球上繁盛而普及以后), 유일한의학잉연유불쇠퇴적생명력(唯一한의學仍然有不衰退的生命力), 저취시양인문표시경희(저就是양人們表示倞喜). 여차동시인문안조서방과학적시각화표준(여此同시人們按照西方科學的시角和표准), 파유일지탱생명력적한의학부단지관찰(把唯一支撑生命力的한의學不단地관察), 검사(檢査), 평가(評價), 요구(要求), 개조(改造). 저양적정황하(저양的情況下), 대표착"의자의야"적한의학불유득수도료허다견책(代表着"의者意也"的한의學不由得受到了許多遣責). 대우연구한의학래설(대于硏究한의學래說), 응해소주여하이해고대의가전래적저구화(應該소注如何理解古代의家전래的구句和). 통과요육군적연구등(通과寥育群的硏究等), 논자요분석이정리(論者要分析而整理), 매시기"의자의야"적다양포함화표연형식(每時基"의者意也"的多양包含和表演形式).

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Strength Characteristics on High Strength Concrete against Sulfate Attack (황산염의 침해를 받는 고강도 콘크리트의 강도특성과 물성변화)

  • Park, Young-Shik;Suh, Jin-Kook;Lee, Jae-Hoon;Shin, Young-Shik
    • Magazine of the Korea Concrete Institute
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    • v.10 no.5
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    • pp.117-128
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    • 1998
  • 화학적으로 유해한 환경에 놓인 콘크리트 구조물은 필연적으로 그 기능이 악화되므로 혼화재를 포함한 고강도 콘크리트 또는 혼화재 그 자체가 화학물질에 오염된 환경하에서 어떤 변화를 일으키는가에 대한 연구의 필요성이 점점 증대되고 있다. 따라서 본 논문에서는 건설현장에서 가장 흔히 사용되는 보통강도 콘크리트와 실리카-흄을 포함한 포틀랜드시멘트 경화체인 고강도 콘크리트가 황산염의 침해를 받는 경우에 일어나는 강도특성과 물성변화를 조사하기 위하여 담수와 함께 황산나트륨, 황산마근네슘, 황산나트륨과 황산마그네슘의 혼합용액 등 여러종류의 황산염 용액에 실리카-흄을 사용한 고강도 콘크리트, 낮은 물-시멘트 비의 고강도 콘크리트, 보통강도의 콘크리트 등의 시험체들을 270일간 침지시켜 침지시간에 따른 압축강도 변화와 실리카-흄의 첨가량에 따른 압축강도 변화, 그리고 실리카-흄의 첨가량에 따른 선형팽창량 및 중량변화등에 관한 실험을 수행하였다. 이에 대한 실험결과를 토대로 실리카-흄을 사용한 고강도 콘크리트에 황산염이 미치는 영향을 분석하여 고강도 콘크리트의 실용성을 극대화하기 위한 방안에 대하여 고찰해보았다. 그 결과 실리카-흄을 포함한 고강도 콘크리트는 황산나트륨의 침해에 대해서는 강한 저항성을 나타내지만 황산마그네슘에 대해서는 심각한 침해를 일으키는 것으로 나타났으므로 황산마그네슘에 노출될 우려가 있는 콘크리트 구조물에 고강도를 발현하기 위하여 실리카-흄을 사용하는 것은 구조적으로 큰 문제가 발생할 것으로 사료된다.

Analysis of Sloshing Problem by Numerical Method (수치기법을 이용한 Sloshing 문제의 해석)

  • Y.H. Kim;Y.J. Park
    • Journal of the Society of Naval Architects of Korea
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    • v.29 no.3
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    • pp.33-44
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    • 1992
  • In the present paper, three types of analytic and numerical method are applied to the analysis of sloshing problem. Analytic solution with linear free-surface boundary condition is introduced and numerical methods are used to analyze flued flow trapped in two-and three-dimensional tanks. Source-distribution method is applied to two- and three-dimensional rectangular tanks and sphere tank. Finite difference method is utilized to compute fluid motion and pressure evolution in two dimensional tanks with girders or slopes. Calculated results are compared with those of experiment or other numerical techniques.

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Large Eddy Simulation of Turbulent Flows over Backward-facing Steps (후향 계단에서 난류 유동에 대한 대와동모사)

  • Hwang, Cheol-Hong;Kum, Sung-Min
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.3
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    • pp.507-514
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    • 2009
  • Large eddy simulation code was developed to predict the turbulent flows over backward-facing steps including a recirculating flow phenomena. Localized dynamic ksgs-equation model was employed as a LES subgrid model and the LES solver was implemented on parallel computer consisting of 16 processors to reduce computational costs. The results of laminar flow showed qualitative and quantitative agreements between current simulations and experimental results availablein literatures. The simulation of the turbulent flows also yielded reasonable results. From these results, it can be expected that developed LES code will be very useful to analyze the combustion in stabilities and noise of a practical combustor in the future.

An experimental study to develop operation technique of solid waste landfill for utilization of biomass (바이오매스 활용형 폐기물 매립지공법 개발을 위한 실험적 연구)

  • Kim, Hye-Jin;Park, Jin-Kyu;Jeong, Min-Kyo;Lee, Nam-hoon
    • Journal of the Korea Organic Resources Recycling Association
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    • v.15 no.1
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    • pp.171-177
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    • 2007
  • In order to investigate the effect of the methanogenic bacteria in bacteria in leachate on the degradability of landfill waste, this study has created 4 cylinder-shape PVC lysimeters (Diameter: 30cm, Height: 200cm, Volume: 140L) and for the biological treatment and recirculation of the leachate, two anaerobic batch reactors (Diameter: 20cm, Height: 30cm) were created. To simulate a conventional landfill, no recycling was done in L1. In L2, 1,068ml of leachate (twice of rainfall amount) was recycled. In L3 and L4, the leachate was anaerobically digested in a dark room (with $35{\pm}1^{\circ}C$) for a week and them recycled by 1,064ml and 2,128ml, respectively, with recycled water only. In terms of cumulative $CH_4$ production, however, L3 and L4 were much higher (three times) than L1 and L2. Between L3 and L4, the latter was 1.23 times higher than the former in terms of cumulative CH4 production. In other words, the more the methanogenic bacteria-activated leachate is recycled, the more active the degradation due to active methane fermentation by the recyled methanogenic bacteria. And methane recovery is different according to the amount of recycled the methanogenic bacteria in leachate.

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