• 제목/요약/키워드: Bottom-up Process Analysis

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상향식 공정분석을 통한 국내 유리산업의 온실가스 인벤토리 산정 (Greenhouse Gas Emission Inventory Calculation of Korean Glass Industry through the Bottom-up Production Process Analysis)

  • 백천현;정용주;유종훈
    • 경영과학
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    • 제32권1호
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    • pp.101-111
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    • 2015
  • The glass production is classified into an energy intensive industry. This study develops a systematic procedure to derive Greenhouse Gas (GHG) emission inventory for the Korean glass industry. Based on the bottom-up approach in which the energy intensity in each production process is characterized, the EBs (energy balances) of glass production processes are derived. And the GHG emission is calculated for each of four types of glasses-flat glass, container glass, fiber glass, and LCD glass.

PSC 연속 거더교의 연속화부 거동에 관한 해석적 연구 (Analysis of the Behaviors of Continuous parts in Continuous PSC Girders Bridges)

  • 구민서;김훈희;정영도
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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    • pp.404-411
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    • 2002
  • The PSC 2-span-continuous-bridge by Up-Down Method on construction process is used for this research. It is measured the strain of lower-steel-plate at continuous section on the active range of negative moment at the stage of introducing compressive stress to bottom-plate and compared with results of structural analysis. On the basis of these results, it is confirmed the introduced compressive stress tか bottom-plate. The object of this research is presenting the degree of continuity at the stage of lifting up process.

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상향식 모형을 이용한 국내 조선업의 온실가스 배출 분석 (A Bottom-up Approach for Greenhouse Gas Emission Analysis of Korean Shipbuilding Industry)

  • 백천현;김후곤;김영진;정용주
    • 경영과학
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    • 제31권1호
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    • pp.41-48
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    • 2014
  • This study presents a bottom-up approach for analyzing greenhouse gas (GHG) emissions for the shipbuilding industry in Korea. The overall procedures for deriving GHG emissions from the Korean shipbuilding industry are presented. Based on the long-term forecast on energy demands of the Korean shipbuilding industry, reference energy system (RES) and energy balance (EB) for the shipbuilding process are derived for bottom-up modeling.

CO2 sequestration and heavy metal stabilization by carbonation process in bottom ash samples from coal power plant

  • Ramakrishna., CH;Thriveni., T;Nam, Seong Young;kim, Chunsik;Ahn, Ji Whan
    • 에너지공학
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    • 제26권4호
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    • pp.74-83
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    • 2017
  • Coal-fired power plants supply roughly 50 percent of the nation's electricity but produce a disproportionate share of electric utility-related air pollution. Coal combustion technology can facilitate volume reduction of up to 90%, with the inorganic contaminants being captured in furnace bottom ash and fly ash residues. These disposal coal ash residues are however governed by the potential release of constituent contaminants into the environment. Accelerated carbonation process has been shown to have a potential for improving the chemical stability and leaching behavior of bottom ash residues. The aim of this work was to quantify the volume of $CO_2$ that could be sequestrated with a view to reducing greenhouse gas emissions and stabilize the contaminated heavy metals from bottom ash samples. In this study, we used PC boiler bottom ash, Kanvera reactor (KR) slag and calcined waste lime for measuring chemical analysis and heavy metals leaching tests were performed and also the formation of calcite resulting from accelerated carbonation process was investigated by thermo gravimetric and differential thermal analysis (TG/DTA).

신제도주의 관점에서의 한국 상향식 농촌지역개발사업 분석 (Analysis of the Bottom-up Rural Development Project viewed from the New Institutionalism in Korea)

  • 김정태;유병욱
    • 농촌계획
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    • 제21권3호
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    • pp.67-84
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    • 2015
  • Although the bottom-up rural area development project was conceived with great expectations, the general evaluation of the project so far reveals that it does not significantly differ from projects carried out in a top-down manner. This paper examines the nature of the bottom-up rural area development project with a focus on its background, including the roles of authority and project participants. Results revealed that the project was designed to be implemented in line with the state affairs ideology of the leader in a negative position of bureaucratic society. Though the form of implementation for the project seemed bottom-up as seen in the process of the roles and authorities in supporting organizations the top-down method of implementation can be seen in the authorities and roles of the central government. It was also noticed that the private sector, designed to elicit participation of various experts, looked to be managed and controlled by public organizations. The abovementioned signifies that the Korea rural area development project has been implemented not in a bottom-up manner but rather in an ever-strong top-down manner, which means that the central government holds more responsibility for the project's results, evaluation, and discussions. Furthermore, as seen in the background of the project, policies have been implemented in a top-down manner without the confidence of the bureaucratic society. Therefore, in order to implement a proper bottom-up rural area development project, there is a need for the bureaucratic society to have confidence in the rural societies.

분말 ECAP 공정 시 치밀화의 유한요소해석 (Finite Element Analysis of Densification Behavior during Equal Channel Angular Pressing Process of Powders)

  • 윤승채;팜쾅;천병선;이홍로;김형섭
    • 한국분말재료학회지
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    • 제13권6호
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    • pp.415-420
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    • 2006
  • Nanostructured metallic materials are synthesized by bottom-up processing which starts with powders for assembling bulk materials or top-down processing starting with a bulk solid. A representative bottom-up and top-down paths for bulk nanostructured/ultrafine grained metallic materials are powder consolidation and severe plastic deformation (SPD) methods, respectively. In this study, the bottom-up powder and top-down SPD approaches were combined in order to achieve both full density and grain refinement without grain growth, which were considered as a bottle neck of the bottom-up method using conventional powder metallurgy of compaction and sintering. For the powder consolidation, equal channel angular pressing (ECAP), one of the most promising method in SPD, was used. The ECAP processing associated with stress developments was investigated. ECAP for powder consolidation were numerically analyzed using the finite element method (FEM) in conjunction with pressure and shear stress.

회전유동에서의 관성진동 원인규명 (Onset of Inertial Oscillation in a Rotating Flow)

  • 박준상
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회B
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    • pp.2536-2539
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    • 2008
  • A study has been made on how to occur inertial oscillations in a rotating flow. The flow is considered to be induced by differentially-rotating top and bottom disks with infinite radius. The top and bottom disks are assumed to be set in motion over a finite initial start-up time duration from initial solid body rotation ($\Omega$) to each finial state, i.e., the top disk is rotating at the angular velocity (${\Omega}+{\Delta}{\Omega}$) and the bottom disk (${\Omega}-{\Delta}{\Omega}$). The system Reynolds number, which is a reciprocal of conventional Ekman number in rotating flows, is very high so that a boundary layer flow near disks is pronounced. From a strict theoretical analysis, it is clearly found the fact that inertial oscillation in a rotating flow is caused by excessive input of torque during start-up phase. Above finding comes from the following physics of theoretical result: in the case of abrupt start-up within very shorter time-duration than spin-up time scale, the inertial oscillation is magnified but it could be completely depressed in the case of mildly accelerated start-up, i.e., start-up process being established over diffusion time scale.

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연속체 개념에 기반한 나노 임프린트 공정해석 연구 (Numerical Analysis Based on Continuum Hypothesis in Nano-imprining process)

  • 김현칠;이우일
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 추계학술대회논문집
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    • pp.333-338
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    • 2003
  • Nano-imprint lithography(NIL) is a polymer embossing technique, capable of transferring nano-scale patterns onto a thin film of thermoplastics such as polymethyl methacrylate(PMMA) using this parallel process. Feature size down 10 nm have been demonstrated. In NIL, the pattern is formed by displacing polymer material, which can be squeeze flow of a viscous liquid. Due to the size of the pattern, a thorough understood of the process through experiments may be very different. Therefore we nead to resort to numerical simulation on the embossing process. Generally, there are two ways of numerical simulation on nano-scale flow, namely top-down and bottom-up approach. Top-down approach is a way to simulate the flow assuming that polymer is a continuum. On the contrary, in the bottom-up approach, simulation is peformed using molecular dynamics(MD). However, as latter method is not feasible yet. we chose the top-down approach. For the numerical analysis, two dimensional moving grid was used since the moving grid can predict the flow front. Effects of surface tension as well as the slip at the boundary were also considered.

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생성모형의 학습을 위한 상향전파알고리듬 (Learning Generative Models with the Up-Propagation Algorithm)

  • 오종훈
    • 한국정보과학회:학술대회논문집
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    • 한국정보과학회 1998년도 가을 학술발표논문집 Vol.25 No.2 (2)
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    • pp.327-329
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    • 1998
  • Up-Propagation is an algorithm for inverting and learning neural network generative models. Sensory input is processed by inverting a model that generates patterns from hidden variables using top-down connections. The inversion process is iterative, utilizing a negative feedback loop that depends on an error signal propagated by bottom-up connections. The error signal is also used to learn the generative model from examples. the algorithm is benchmarked against principal component analysis in experiments on images of handwritten digits.

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상향식접근(bottom-up approach)이론을 이용한 창작산실육성지원사업의 효과연구 (Bottom-up Approach: the Effects of Performing Arts Fostering Program, Chang-jak-san-shil)

  • 김인설;신혜선;이흥재
    • 문화경제연구
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    • 제19권2호
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    • pp.97-120
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    • 2016
  • 아무리 좋은 목적을 가진 정책이라도 본래 의도한 결과를 적절한 평가 및 보완과정 없이 단번에 실현하는 경우는 드물다. 이 논문은 '창작산실육성지원사업의 정책대상자인 예술가들은 동 사업의 효과와 문제점을 어떻게 바라보고 평가하는가?'를 연구문제로 설정하여, 정책집행과정연구의 한 방식인 상향식접근(bottom-up approach)이론을 통해 정책현장의 관점을 체계적으로 분석했다. 연구방법으로 초점집단면접(FGI)과 개인심층면접(PII)을 사용하였으며, 자료의 수집은 2015년 9월부터 약 3달간 진행되었다. 연구참여자는 총 28명으로 창작산실사업을 통해 지원받은 예술가그룹(n=21)과 심사에 참여했던 전문가그룹(n=7)으로 구성하여 직접적인 수혜자가 바라본 정책사업에 대한 인식과 평가를 보다 객관적으로 이해할 수 있도록 설계했다. 자료 분석결과, 일부 긍정적인 사업의 성과에 있어 공통의 합의점을 찾을 수 있었으나 작품지원 후 작품에 대한 사후지원, 유통 및 관리, 심의과정에 대한 공정성과 심의위원 위촉과정의 투명성, 단계별 심사의 장르적 특성을 반영한 유연한 설계 및 심의결과 공개를 통한 예술계와의 소통 등이 반드시 개선되어야 할 사항으로 도출되었다. 본 논문은 상향식접근이론을 준거로 예술지원사업의 정책대상자를 통해 공공기금의 적절한 운용과 이에 따른 예술계의 발전방향에 실질적이고 구체적인 제언을 도출하였다.