• Title/Summary/Keyword: 창호재

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An Object-Oriented Design Model for Electronic Commerce Product Database (전자상거래 플랫폼에서의 객체지향 상품 클래스 설계기법)

  • 최창호;김수동
    • Proceedings of the CALSEC Conference
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    • 1997.11a
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    • pp.31-41
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    • 1997
  • 현재 운영중인 대부분의 전자상거래 시스템들은 서적, 의류, 컴퓨터등 특정 상거래 분야에 종속적으로 데이터베이스 및 운영 시스템이 개발되어 있다. 그러나, 전자상거래가 본격적으로 활성화되면 거의 모든 상품 및 서비스가 전자상거래의 대상이 될 것이므로, 전자상거래 제품 데이터베이스의 설계를 여러 도메인에서 다양한 상품들의 정보를 저장 할 수 있도록 범용적으로 설계하여야 한다. 본 논문에서는 전자상거래 공통 플랫폼 개발의 중요한 구성요소인 상품 데이터베이스의 클래스를 객체지향 방식으로 설계하여 재사용성, 적용성, 범용성을 극대화하는 기법을 제안한다. 또한, 제안한 객체지향 상품 클래스 설계기법을 이용한 사례연구를 통하여 그 적용방법을 구체적으로 설명한다.

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Thermal Analysis of Composite Satellite Antenna Structure in Space Environment (복합재 통신위성 안테나의 우주환경 열해석)

  • ;;;;Frank Gilles
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.77-80
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    • 2002
  • Thermal analysis has been performed to evaluate the thermal effect on composite antenna (Ka-band) structure in space environment. The concepts of thermal control are also presented to maintain the antenna components within respective temperature limits. A steady-state algorithm of I-DEAS' thermal analysis software was utilized to predict both maximum and minimum temperature, maximum gradient temperature, and temperature distribution on each antenna component.

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ESCO Column 1 - 그린 빌딩 설계기법과 기술 - 친환경 건축의 바른 길

  • Choe, Yeong-Ho
    • The Magazine for Energy Service Companies
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    • s.64
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    • pp.14-17
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    • 2010
  • 친환경 건축물은 자연친화적인 건물을 실현해 사용에너지를 최소화하고 탄소배출을 줄이는 것을 목표로 한다. 에너지사용을 먼저 줄인 후 그 다음 신재생에너지로 필요한 에너지를 충당해야 한다는 것. 때문에 친환경 건축 설계기법으로 최적향 선택과 에너지효율화를 높일 수 있는 외피시스템, 고성능 단열재, 고 단열 창호, 폐열회수환기시스템 등이 거론되고 있다. 친환경 건축의 바른 길을 위해 숙지해야 할 요소를 짚어보았다.

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The Trends of Digital Beamforming Antenna Technology (Digital Beamforming(DBF) 안테나 기술 동향)

  • Bae, C.H.
    • Electronics and Telecommunications Trends
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    • v.21 no.2 s.98
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    • pp.200-209
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    • 2006
  • 가입자의 수가 놀라운 비율로 증가하고 고품질. 광대역 데이터 통신에 대한 요구가 증가하면서 이동 통신에 사용되는 주파수원이 부족하게 될 것으로 예상된다. 주파수의 재사용률을 향상시키기 위하여 공간적인 방향성을 가지는 안테나를 이용하는 것과 송신하는 전력을 줄이는 것은 주파수원의 효율적인 사용을 할 수 있게 할 것이다. 가까운 미래에는 도달하는 신호를 빨리 추적하는 높은 이득을 가지는 안테나가 많이 요구될것이고 빠르게 성장할 것으로 기대된다. 그런 다양한 기능을 가지는 안테나를 실현하기 위하여 디지털 빔 형성 안테나가 미래의 지능 안테나로 제안되었다[1], [2]. 따라서 본 논문에서는 디지털 빔 형성(digital beam forming, 이하 DBF라 한다.) 안테나의 빔형성 방법, 원리, 특징에 대하여 살펴볼 것이다.

Structural Characteristics of Reinforced Concrete Beam-Column Joints Repaired and Restrengthening (재보수-보강된 철근콘크리트 보-기둥 접합부의 구조특성)

  • Cho, Chang-Ho;Kim, Jeong-Sup
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.7 no.2
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    • pp.231-238
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    • 2003
  • Reinforced concrete buildings damaged by earthquake which can be reused can ensure the stability in its structure by repair-restrengthening, but when such a repair-restrengthening is conducted inappropriately or its structural strength is greatly reduced by earthquake again, it should have repair-restrengthening. This study selects beam-column joints which are vulnerable to earthquake as the object of experiment, performs repair-restrengthening after applying the first and the second dynamic loading to the objects of experiment, examines the capacity of restrengthening according to structural characteristics and loading velocity and verifys the validity of repair-restrengthening.

Effect of the Recycling of Non-condensable Gases on the Process of Fast Pyrolysis for Palm Wastes (미응축가스 재순환에 따른 팜 부산물 급속열분해 반응 공정 특성)

  • Oh, Changho;Lee, Jang Hoon
    • Clean Technology
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    • v.24 no.3
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    • pp.233-238
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    • 2018
  • Bio-oil is produced by the fast quenching of hot vapor produced by fast pyrolysis of biomass in an inert atmosphere. Nitrogen is used as carrier gas to control the concentration of oxygen less than 3%. The consumption of nitrogen should be increased with increasing process size, and leading to increasing of facility and operating costs due to nitrogen charge. The effects of the recycling of non-condensable gases on the fast pyrolysis, bio-oil yield and quality, and nitrogen consumption have systematically investigated to see the possibility of these results in fast pyrolysis process of palm residue.

Analysis of Heavy Metal Contaminated Soils Remediation Using Reactive Drains (반응성 배수재를 이용한 중금속 오염토양의 정화효율 분석)

  • Park, Jeongjun;Choi, Changho;Shin, Eunchul
    • Journal of the Korean Geosynthetics Society
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    • v.12 no.1
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    • pp.29-38
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    • 2013
  • This paper presents the analysis condition of remediation technique of contaminated fine-grained soil and physical properties of bio-degradable drain for analysis site applicability using bio-degradable drain method. As the result, two kinds of developed degradable drains (cylindricality shaped and harmonica shaped) are satisfied the Korean Industrial Standard. And the cylindricality shaped drain has an excellent discharge capacity than that of another one. By the results of laboratory test, the citric acid is chosen as the washing agent because it has low toxicity, so it is able to minimize harmful influence to environment. Furthermore the subject contaminants were selected as Cd, Cu and Pb. Based on the field pilot test results, the most remedial efficiency is the use of reactive material applied in bio-degradable drain method with the process of injecting the washing agent and extraction of contaminated fluid.

A Study on Relationship Insulation Thickness and Infiltration Load by Window (단열재 두께 변화와 창호 침기 부하와의 관계)

  • Choi, Jeong-Min;Cho, Sung-Woo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.24 no.5
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    • pp.422-427
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    • 2012
  • This study investigates on the relationship between total load which is caused by infiltration and insulation thickness against compensation effect. As the result of experiment, the PVC(Synthetic resins sash) window frame in airtightness is superior to the AL(Aluminum sash) window frame. In this study, as the increasing of insulation thickness in reference building does not reduce significantly cooling load, the compensation effect due to airtightness against infiltration is very small. But the compensation effect against infiltration can be closely related with heating load. Therefore, the proper thermal insulation thickness can be needed respect to cooling and heating load.