• 제목/요약/키워드: Investigation environment factor

검색결과 258건 처리시간 0.024초

발포 알루미늄이 삽입된 환형관에서의 열전달 및 유동특성 (Heat Transfer and Flow Characteristics in an Annulus Filled with Aluminum Foam)

  • 노주석;한영희;이계복;이충구
    • 에너지공학
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    • 제15권1호
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    • pp.60-66
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    • 2006
  • 발포 알루미늄이 삽입된 환형관에서의 유동과 대류 열전달 특성을 실험적 연구를 수행하여 분석하고 heat sink로서의 실현 가능성을 검토하였다. 다른 기공밀도를 갖는 두 종류의 발포 알루미늄을 사용하여 유동과 열전달 특성을 파악하고 마찰계수와 열전달 관련 Nusselt수를 Darcy 수, Reynolds수, Prandtl수의 함수로 상관식을 구하였다. 발포 알루미늄이 없는 경우에 비해 마찰계수는 증가하지만 Nusselt수에서도 6에서 10배의 증가를 나타낸다. 따라서 열교환기의 크기가 제한되는 경우 열교환기에 발포알루미늄을 삽입하면 전열면적을 감소시킬 수 있으므로 열교환기를 소형화할 수 있다.

온라인 창의성 교육에 있어 학습 환경과 교육 프로그램의 특성에 관한 실증연구 (Experimental Investigation of the Effects of Learning Environment and The Nature of Educational Program on the Outcome of Creativity Training)

  • 조남재;하주현
    • 한국경영과학회지
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    • 제27권3호
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    • pp.135-144
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    • 2002
  • The purpose of this study is to examine the effects of computer-based creativity training. Four groups of vocational high school students totaling 151 were used as experimental subjects. Two dimensions of treatment were designed. One treatment dimension is the use of computer medium in education: computer based vs. paper-pencil setting of education. The second treatment dimension is the method of creativity training: technique-oriented training program vs. factor-oriented training program. Both a pretest and a post-test were administered to all participated students. The tests were composed of a Creative Figural Test and a Creative Product Test. After the pretest 8 sessions of creative training were delivered as intended in the design of the experiment. The Dost-test was arranged a week after the completion of the training sessions. The results of the study include: First, all the 4 groups showed certain amount of improvements in their scores of Creative Figural Test, while no improvements was observed in the creative product test score. Second, the technique-oriented creativity training was more effective than the factor-oriented under the context of computer-based education, and the factor-oriented training was more effective in the paper-pencil setting. The results suggest that different pedagogical approaches should be employed for computer-based training as compared to the paper-pencil education.

고등학생의 시간관리행동에 따른 교육소비만족도 및 학교생활만족도 (The Effects of the High School Students' Time Management Behavior on Satisfaction with Educational Consumption and School Life)

  • 이경민;이승신
    • Human Ecology Research
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    • 제53권1호
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    • pp.1-16
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    • 2015
  • This study aims to examine the effects of high school students' time management behaviors on their satisfaction with educational consumption and school life. Three hundred seventy-six high school students in Seoul participated in this investigation. The SPSS ver. 19.0 program was adopted for the descriptive analysis, factor analysis, Cronbach's ${\alpha}$, and multiple regression analysis. The results of the present study can be summarized as follows: first, the levels of time management behavior, satisfaction with educational consumption at school, and satisfaction with school life were relatively high. Second, an analysis of the relative influence on satisfaction with educational consumption revealed that the students' time management behavior was the most influential factor, followed by academic achievement. As the levels of time management behavior and academic achievement were high, the level of satisfaction with educational consumption was high. Finally, an analysis of the relative influence of satisfaction with school life also revealed that the students' time management behavior was the most influential factor, followed by academic achievement. Based on the findings, that is, the effects of high school students' time management behavior and other involved variables on their satisfaction with educational consumption and school life, a future study can present specific ways to enhance the level of satisfaction with educational consumption and school life.

염해 환경에 노출된 RC 구조물의 내구성능설계를 위한 퍼지 추론 기반 환경영향지수의 산정 (Fuzzy Inference-based Quantitative Estimation of Environmental Affecting Factor For Performance-based Durability Design of RC Structure Exposed to Salt Attack Environment)

  • 도정윤;송훈;소승영;소양섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
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    • pp.237-240
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    • 2005
  • As a part of the effort for improving the durability design based on a set of the deem-to-satisfy specifications, it is important and primary to quantitatively identify the environmental impact to a target reinforced concrete structure. In this work, an effort is made to quantitatively calculate the environmental affecting factor with using a fuzzy inference that it indicates the severity of environmental impact to the exposed reinforced concrete structure or member. This system is composed of input region, output region and rule base. For developing the fuzzy inference system surface chloride concentration{chloride), cyclic degree of wet and dry(CWD), relative humidity(RH) and temperature (TEMP) were selected as the input parameter to environmental affecting factor(EAF) of output parameter. The Rules in inference engine are generated from the engineering knowledge and intuition based on some international code of practises as well as various researcher's experimental data. The devised fuzzy inference system was verified comparing the inferred value with the investigation data, and proved to be validated. Thus it is anticipated that this system for quantifying EAF is certain to be considered into the starting point to develop the performance-based durability design considering the service life of structure.

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수치해석을 이용한 하천제방의 건전도 평가 (River Embankment Integrity Evaluation using Numerical Analysis)

  • 변요셉;정혁상;김진만;최봉혁;김경민;천병식
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2009년도 세계 도시지반공학 심포지엄
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    • pp.524-528
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    • 2009
  • An influence factors for soundness evaluation of river levee include resistibility and embankment for piping of ground consisting embankment in case piping, permeability coefficient of ground, height of embankment, the width of crest, material characteristics of embankment and foundation ground, shape of embankment slope, an influence for penetration of rainfall or river water in case slope stability. In this study, it was operated a feasibility investigation of existing design result, stability evaluation for permeability coefficient use and permeability coefficient change of foundation ground to investigate an influence in line with permeability coefficient change for result of river levee penetration analysis. The evaluation results of influence factors, the permeability coefficient used in design and it was evaluated influence in safety factor of piping. After the evaluation of influence factors, the permeability coefficient used in the design appears with the fact that differs in a design report about same soil, Accordingly, the stability investigation of embankment by application of literature data can affect stability evaluation results by change factors like a permeability coefficient, void ratio. It should be certainly used material properties by a test in soundness evaluation of river levee.

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Studies on Pollution Characteristics and Sources of Precipitation in Jeiu Island

  • Kang, Chang-Hee;Kim, Won-Hyung
    • Journal of Korean Society for Atmospheric Environment
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    • 제18권E4호
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    • pp.191-201
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    • 2002
  • The pH, electric conductivity. and the major ionic components were analyzed for the precipitation samples collected at 1100 Site of Mt. Halla and Jeju city. The quality of analytical data was verified by the comparison of ion balances, conductivities and acid fractions, all of which correlation coefficients were over 0.952. The ionic strengths lower than 10$^{-4}$ M were found in 57 and 28% at 1100 Site and Jeju city respectively. The precipitation in Jeju city was influenced more by the oceanic effect than those in 1100 Site. The acidification of precipitation was caused mostly by S $O_4$$^{2-}$and N $O_3$$^{[-10]}$ in both areas, and the organic acids have contributed to the acidity with only 7~8%. The neutralization factors by N $H_3$ were about 44 and 47% at the 1100 site and the Jeju city, respectively, whereas those by CaC $O_3$were 21 and 24%, and the free acidity were about 38 and 28% at two sites. From the investigation of seawater and soil enrichment factors, the S $O_4$$^{2-}$, N $O_3$$^{[-10]}$ and N $E_4$$^{+}$ were immigrated by other sources rather than from the seawater or soil origins. but not in the case of $Mg^{2+}$, C $l^{[-10]}$ , N $a^{+}$, and $K^{+}$. Factor analysis has shown that the precipitation at the 1100 site had been influenced mostly by anthropogenic sources, followed by soil and sea-water sources. On the other hand, the precipitation at the Jeju city was mainly influenced by oceanic sources, followed by anthropogenic and soil sources.urces.

실내 공간 디자인에서의 환경마케팅에 관한 기초연구 (A Study on the Basis of Environmental Marketing in interior Space design)

  • 우수진;한혜련
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2007년도 추계학술발표대회 논문집
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    • pp.139-144
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    • 2007
  • Although human beings have been able to lead the affluent life owing to industrialization and development of science and technology, as the result of this, the nature has be destroyed, energy consumption has been accelerated, urban area has got wide and the nature has got narrow. In the face of such critical situations, concerns have been aroused to environment. In order to minimize the environment destruction and accompany the aesthetic, efficient and advantage methods, environmental marketing has been introduced to indoor. Environmental marketing is the marketing that minimizes the reverse function so as to obtain the satisfactory result, and it is still in the stage of fundamental investigation. stage. As the concept and type of environmental marketing have not been established yet for interior design, environmental marketing currently applied to indoor space is classified Into three types in this study. Through the four types of environmental marketing, which are the introduction of natural elements to indoor space, the use of eco-friendly materials and the use of sustainable materials, renovation it is intend to derive the environmental marketing strategy and present the sequence of strategy establishment and desirable direction in environmental marketing.

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Investigation of Effect of Input Ground Motion on the Failure Surface of Mountain Slopes

  • Khalid, Muhammad Irslan;Pervaiz, Usman;Park, Duhee
    • 한국지반환경공학회 논문집
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    • 제22권7호
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    • pp.5-12
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    • 2021
  • The reliable seismic stability evaluation of the natural slopes and geotechnical structures has become a critical factor of the design. Pseudo-static or permanent displacement methods are typically employed to evaluate the seismic slope performance. In both methods, the effect of input ground motion on the sliding surface is ignored, and failure surface from the limit equilibrium method is used. For the assessment of the seismic sensitivity of failure surface, two-dimensional non-linear finite element analyses are performed. The performance of the finite element model was validated against centrifuge measurements. A parametric study with a range of input ground motion was performed, and numerical results were used to assess the influence of ground motion characteristics on the sliding surface. Based on the results, it is demonstrated that the characteristics of input ground motion have a significant influence on the location of the seismically induce failure surface. In addition to dynamic analysis, pseudo-static analyses were performed to evaluate the discrepancy. It is observed that sliding surfaces developed from pseudo-static and dynamic analyses are different. The location of the failure surface change with the amplitude and Tm of motion. Therefore, it is recommended to determine failure surfaces from dynamic analysis

Testosterone 처리에 의한 넙치, Paralichthys olivaceus 난소에서 doublesex-and mab-3-related transcription factor-1 (DMRT-1) mRNA의 발현 유도 (Induced Expression of Doublesex-and mab-3-related Transcription Factor-1 (DMRT-1) mRNA by Testosterone in the Olive Flounder, Paralichthys olivaceus ovary)

  • 조필규;안광욱;김나나;최용기;조성환;민병화;임한규;최철영
    • 한국양식학회지
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    • 제20권3호
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    • pp.199-202
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    • 2007
  • 본 연구에서는 넙치(Paralichthys olivaceus) 정소로부터 DMRT-1 partial cDNA를 분리하였다. 넙치 DMRT-1은 317개의 염기로 구성되어 있으며, Atlantic halibut, 감성돔 및 무지개 송어와 각각 94%, 85%, 82%의 높은 상동성을 보였다. RT-PCR을 이용하여 DMRT-1 mRNA 발현은 난소보다 정소에서 높게 나타난 것을 관찰할 수 있었다. 또한, 암컷 넙치에 웅성호르몬인 testosterone 처리시 처리 농도에 따라 난소에서 DMRT-1 mRNA 발현이 증가함을 볼 수 있었다. 따라서, DMRT-1은 수컷에서 특이적으로 발현되는 유전자임을 알 수 있으며, 본 연구의 결과는 넙치의 성 전환 및 유도에 대한 기초자료를 제공할 것이다.

도시재생을 위한 부산시의 재생지역 분석에 관한 연구 (A Study on the Regional Regeneration Analysis for Urban Regeneration in Busan)

  • 김흥관;강기철
    • 한국지리정보학회지
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    • 제11권1호
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    • pp.167-177
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    • 2008
  • 도시재생은 쇠퇴한 도시지역을 물리 환경적, 경제적, 생활 문화적으로 개선하여 활력이 저하된 기능을 회복함과 동시에 경쟁력 있는 정주환경으로 재창조하는 과정이라 할 수 있다. 본 연구에서는 건축물DB를 구축하여 행정상 편의를 위해 분류한 최소구역인 행정동별로 노후도를 분석하여 객관적인 통계자료와 부산광역시의 도시정비현황과의 연계를 통한 도시재생을 위한 권역설정의 척도를 제시하고자 하였다. 또한 아직 법기준이 명시되지 않은 실정으로 현재의 도시및주거환경정비법과 도시재정비촉진을 위한특별법을 기준으로 다양한 정량적 분석을 통해 도시재생의 체계를 구축하고 기존의 법 제도의 문제점을 도출하여 향후 도시재생사업의 기초자료로 활용하는데 그 목적이 있다. 또한 건축물 노후도의 물리적인 낙후정도의 측정만이 아닌 동단위로 구축할 수 있는 인구, 사회, 복지, 사업체 등의 각 분야의 변수들간의 특징과 유형화과정을 요인분석을 통해 재생이 필요한 지역을 파악하였다.

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