• Title/Summary/Keyword: Bottom-Up

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A Study on the Liquefaction Behavior of Bottom Ash (Bottom Ash의 액상화 저항특성 연구)

  • Yoon, Won-Sub;Chae, Young-Su
    • Journal of the Korean Geotechnical Society
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    • v.27 no.6
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    • pp.63-79
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    • 2011
  • In this study relative density tests of bottom ash and standard sand were carried out. And cyclic triaxial tests for samples with the relative density of 40%, 55%, and 70% were carried out on the basis of the test results. Cyclic triaxial tests were also conducted for fines content with 55% relative density. Residual samples were divided into No.40, No.60, No.60, and No.100, and No.200. In order to avoid crashing that can happen when compaction of the sample is initiated, bottom ash was crushed using the a compact mold. In consideration of the crushing characteristics of each residual samples, the fragmentation rate increased up to 30%, which led to the adjustment of fine-grained amount to 10%, 20%, and 30%. Through the repative triaxial test in accordance with the relative density, resistant characteristics of the liquefaction of bottom ash was analyzed. Test results show that, crushing strength of bottom ash was smaller than that of standard sand, resulting in different liquefaction behavior characteristics. And we could find fines content with maximum resistant characteristics of the liquefaction.

A Study on Methodology of U-City Promotion(Top-Down vs Bottom-Up Approach Model) (U-City 추진방법론에 대한 고찰(Top Down vs Bottom Up 모델))

  • Lee, Sang-Hun;Kim, Hyong-Bok
    • Spatial Information Research
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    • v.17 no.1
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    • pp.131-144
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    • 2009
  • Recently, a lot of local autonomous entities are promoting Ubiquitous City(U-City) Construction by integrating Information Communication Technology(ICT) with city development, and also internationally, a lot of cities are making efforts to develop U-City to intensify a city's competitive strength and improve life quality of city dwellers. In keeping with such a stream of the times, each local autonomous entity and project developer are developing a lot of methodologies to establish optimal U-City in corresponding cities and also inquiring into a variety of development procedures, such as connecting existing urban development methods with information establishment methods. The method used usually is to establish Information strategy Plan(ISP) for a city which will be developed through consulting in the stage of city development planning. ISP is to establish vision & strategy for building the ubiquitous city and is a methodology including city vision, strategy, goal, and implementation method, etc. However, due to a lot of variables, such as a variety of city environment, establishment period, budget, information technology, and etc., it is difficult to contain establishment plans for every occasion in a similar method, in reality. Therefore, it is naturally necessary to suggest plans for city vision & strategy, and selection of element technology/service. Thus, this paper suggests models for vision & strategy establishment of U-City and suggests Top-Down Approach and Bottom-Up Approach method as a plan for U-City establishment. In addition, this paper analyzes general promotion methodologies for constructing U-City and analyzes how these two strategic methods [Top-Down Approach and Bottom-Up Approach] for city vision establishment are composed in such a methodology, to define and analyze its constituent plan.

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

  • Kim, InSul;Shin, Hyesun;Lee, Heungjae
    • Review of Culture and Economy
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    • v.19 no.2
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    • pp.97-120
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    • 2016
  • This study aims to identify how performing artists in Korea, who are the target beneficiaries of the Arts Council Korea's Performing Arts Fostering Program, Chang-jak-san-shil(CJSS), would perceive and assess the current state of CJSS and its effects. To do so, this paper has adopted a bottom-up approach as a theoretical lens for policy evaluative analysis. This research engages with qualitative research design by conducting a series of in-depth interviews and FGIs with 28 participants in total. The interview participants consist of CJSS grantees(n=21) and peer-review panels(n=7) based on the intension to enhance objectivity and reliability of the study. Results of the data analysis suggest that the grant program still carries pressing needs to achieve a success as follows: providing post-program support, enhancing transparency of the panel appointment process and the peer review process, reflecting different nature of each arts discipline, and having more open communications with arts professionals. Based on these findings, this paper will provide and discuss about policy implications which can contribute to the performing arts domain at large.

The Study on the transition of types of Deul-E-Yul-Gae windows and doors in Korean traditional architecture - focused on the wall between Dae Chung and Bang - (傳統建築의 들어열개 窓戶形式 變遷에 관한 硏究 - 廳房間을 중심으로 -)

  • 정명섭
    • Journal of the Korean housing association
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    • v.7 no.2
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    • pp.57-68
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    • 1996
  • The study is to investiagte the transition of types of Deul-E-Yul-Gae(lift up) windows and doors in Korean traditional architecture which was on the wall batween Dar Chung and Bang. As the result of studying and analysizing the transition of those the following conclusion could be obtained. The first type was to attach windows on the middle of Deul-E-Yul-Gas(lift up) doors, the second type remove windows attached on that or be(Maeng-Jang-Jee) dark paper covered door annexed Bool-Bal-Gee, and the third type to be (Myung-Jang-Jee) bright paper covered door of bottom panel slender ribs which was the most openness. Finally, we could understand the transition which would be changed from the type of(Maeng-Jang-Jee) bright paper covered lift up door of bottom panel slender ribs that had a pliable and open mood.

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Effective Implementation Strategies for Co-Utilization Policy of Research Equipments: From the Perspective of Bottom-up Apprach in Policy Implemention (연구장비 공동활용 정책의 집행 효율화 방안: 정책집행의 상향적 접근 중심으로)

  • Yi, Chan-Goo
    • Journal of Korea Technology Innovation Society
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    • v.19 no.2
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    • pp.358-394
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    • 2016
  • In Korea, co-utilization of research equipments has been low, even though co-utilization policies for them have been implemented for a long time. This situation results because the policy formation and implementation for the co-utilization of research equipments have been conducted from the perspectives of the policy maker not from those of the researchers and equipment managers. Therefore, this work has been conducted for analyzing the current state of co-utilization of research equipments as well as for discussing the future developments of its more co-utilization in the basic research programs by adopting the bottom approach in policy implementation theory. The research shows that firstly principal investigators, especially professors in universities, have placed a relatively low priority on the co-utilization of research equipments, secondly implementation resources such as high quality technicians and affordable budget for co-utilization are scare, thirdly incentives for the activation of co-utilization in the stage of daily operation of research equipments are lacking. As a result, the study tries to develop a more economic means and information tools for the promotion of co-utilization of research equipments in the perspectives of bottom-up approach in policy implementation theory.

Cause of Break-up and Flotation Characteristics for Sludge from DAF Process (DAF 공정에서 발생한 슬러지의 Break-up 원인과 부상 특성)

  • Yoo, Young-Hoon;Moon, Yong-Taik;Kim, Seong-Jin;Lee, Kwang-Joon;Kwak, Dong-Heui
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.5
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    • pp.527-536
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    • 2010
  • Although the bubble-floc agglomerate floated and formed the float layer on the surface of the water in the DAF process, after inducing in the thickening tank a part of the bubble-floc agglomerate come up again to the surface and the other is settled at the bottom of the tank. The bubble-floc agglomerate divided into two group as the scum on the surface and the sludge of the bottom gives rise to operational troubles for the thickening process. In order to find out the cause of break-up and the effective thickening method for sludge from the DAF process, the composition of the bubble-floc agglomerate was investigated and a series of flotation experiments carried out. There was no difference of composition between the scum on the surface and the sludge of the bottom in the thickening tank. The coagulation was not effective to improve the trouble that the bubble-floc agglomerate divided into the scum and the sludge. It was estimated that for the bubble-floc agglomerate of thickening tank the trouble was caused by not the change or the difference of chemical composition but whether the bubble-floc agglomerate hold bubbles. Furthermore, for the effective thickening of sludge from the DAF process, it is required an additional flotation applied the AS ratio depending upon the solid concentration of sludge as the operation parameter.

Behavior of Soft Ground Throughout Mock-up Test Using Low Self Weight Banking Method (경량성토 모형시험을 통한 연약지반상의 성토제체의 거동)

  • Kim, Sang Chel
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.15 no.6
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    • pp.85-91
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    • 2011
  • This study aims at evaluating feasibility of Bottom ash-mixed Foam Cement Banking(BFCB) Method on the enhancement of soft soil, which is developed to reduce self-weight of banking by applying bottom ash and foam. to cement slurry. In order to measure the behavior of soil when BFCB layer was covered to soft ground, a testing equipment for mock-up test was fabricated and phased loads were applied up to measurement of yielding and ultimate strengths as well as movement of ground particles. In addition, these measured values such as settlement and heaving were compared with ones of surface-hardening method prevailing on soil improvement. As the result through mock-up test, BFCB showed lower values of ground deformation, while wider range of deformation was observed in compare to the other method. And settlement and heaving were measured lower, which implies the method developed is very effective to applicability of soft ground.

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
    • Journal of Energy Engineering
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    • v.26 no.4
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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).

Effects of Bottom Inflow Area on Pool Boiling Heat Transfer in a Vertical Annulus (하부 유로단면적이 수직 환상공간 내부 풀비등열전달에 미치는 영향)

  • Kang, Myeong-Gie;Yoo, Joo-Sik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.31 no.7 s.262
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    • pp.604-610
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    • 2007
  • To investigate effects of the inflow area on pool boiling heat transfer in a vertical annulus, the inflow area at its bottom has been changed from 0 to $1060.3mm^2$. For the test, a heated tube of 34 mm diameter and water at atmospheric pressure have been used. To elucidate effects of the inflow area on heat transfer results of the annulus are compared to the data of a single unrestricted tube. The change in the inflow area at the bottom of the annulus results in much variation in heat transfer coefficients. When the inflow area is $113.1mm^2$ the deterioration point of heat transfer coefficients gets moved up to the higher heat fluxes because of the convective flow at the bottom regions.

Characterization of Pt Bottom Electrode Deposited on Sputtered-Ru/polysilicon by Metalorganic Chemical Vapor Deposition (유기금속 화학증착법에 의해 Sputtered-Ru/Polysilicon 위에 증착된 Pt 전극의 특성)

  • Choe, Eun-Seok;Yang, Jeong-Hwan;Yun, Sun-Gil
    • Korean Journal of Materials Research
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    • v.9 no.4
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    • pp.368-372
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    • 1999
  • The suggested electrode structure of MOCVD-Pt/sputtered-Ru/polysilicon has an excellent adhesion with increasing annealing temperatures and shows a stable electrode structure up to $600^{\circ}C$. However, the ruthenium used for barrier layer increased the roughness of platinum bottom electrodes because ruthenium diffused through the Pt bottom electrode and reacted with oxygen during the annealing above $700^{\circ}C$. The surface roughness increased the resistivity of Pt bottom electrodes. The resistivity of samples annealed at $600^{\circ}C$ was about $13\mu$Ω.cm. The electrode structure was possible to apply for ferroelectric thin film integration of semiconductor memory devices.

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