• Title/Summary/Keyword: 동질성 및 이질성

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Development of A Dynamic Departure Time Choice Model based on Heterogeneous Transit Passengers (이질적 지하철승객 기반의 동적 출발시간선택모형 개발 (도심을 목적지로 하는 단일 지하철노선을 중심으로))

  • 김현명;임용택;신동호;백승걸
    • Journal of Korean Society of Transportation
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    • v.19 no.5
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    • pp.119-134
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    • 2001
  • This paper proposed a dynamic transit vehicle simulation model and a dynamic transit passengers simulation model, which can simultaneously simulate the transit vehicles and passengers traveling on a transit network, and also developed an algorithm of dynamic departure time choice model based on individual passenger. The proposed model assumes that each passenger's behavior is heterogeneous based on stochastic process by relaxing the assumption of homogeneity among passengers and travelers have imperfect information and bounded rationality to more actually represent and to simulate each passenger's behavior. The proposed model integrated a inference and preference reforming procedure into the learning and decision making process in order to describe and to analyze the departure time choices of transit passengers. To analyze and evaluate the model an example transit line heading for work place was used. Numerical results indicated that in the model based on heterogeneous passengers the travelers' preference influenced more seriously on the departure time choice behavior, while in the model based on homogeneous passengers it does not. The results based on homogeneous passengers seemed to be unrealistic in the view of rational behavior. These results imply that the aggregated travel demand models such as the traditional network assignment models based on user equilibrium, assuming perfect information on the network, homogeneity and rationality, might be different from the real dynamic travel demand patterns occurred on actual network.

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An analysis of effect for grouping methods corresponding to ecological niche overlap of 7th graders' photosynthesis concepts (7학년 광합성 개념의 지위 중복 변화에 따른 소집단 구성의 효과 분석)

  • Jang, Hye-ji;Kim, Youngshin
    • Journal of Science Education
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    • v.41 no.2
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    • pp.195-212
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    • 2017
  • Small group learning is an educational approach to allow students to solve the problems and to achieve a common goal. Especially, small group learning in science education is one of the most important educational approaches and effective to ensure understanding of a topic. Small group learning consisting of three students in science education maximize student understanding and learning efficiency. However, It is reported that the effects of small group learning on achievement show different results, corresponding to different grouping methods(homogeneous/heterogeneous). This study investigated the effects of grouping method on difference of ecological niche of photosynthesis concepts. To achieve this, 1107 7th students were composed of homogeneous and heterogeneous groups classified into top, middle, and bottom levels. The photosynthesis units were divided into four categories: the photosynthesizing place, the substances of photosynthesis, required materials for the photosynthesizing, and environmental factors affecting photosynthesis. A questionnaire was composed by selecting concepts having a frequency of 4% or more based on prior studies on the change of the ecological status of photosynthesis. The questionnaire was scored in terms of relativity and understanding on each of the proposed concepts in the four categories. The result of this study is as set forth below. 1) There was an enhancement of learning the concept of science in small group classes consisting of 3 students. 2) To enhance the average upon composing of a group, it is proposed that the group should be formed homogeneously, and to reduce the deviation between the members, it is proposed that the group should be formed heterogeneously. Through this study, it is expected that specific studies verifying the difference or effect on the duplicity of results are conducted based on the composition of groups.

Application of Nonstatinoary Regional Frequency Analysis Based on Population Index Flood Model (모분포 홍수지수모형을 이용한 비정상성 지역빈도해석 기법 적용)

  • Kim, Hanbeen;Lee, Joohyung;Park, Jaeheyon;Heo, Jun-Haeng
    • Proceedings of the Korea Water Resources Association Conference
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    • 2020.06a
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    • pp.98-98
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    • 2020
  • 모분포 홍수지수모형은 여러 관측지점의 수문자료를 활용하여 설계수문량을 산정하는 지역빈도해석을 위한 모형 중 하나이다. 기존의 홍수지수모형은 동질지역 내 각 지점의 표본통계량을 통해 표준화된 자료들을 기반으로 설계수문량을 산정하므로 왜곡이나 오차가 발생하는 반면, 모분포 홍수지수모형은 미지의 모분포에 대한 통계량으로 표준화한 설계수문량은 동질지역 내 모든 지점에 대해 동일하다는 가정을 기반으로 지역빈도해석을 수행하므로 보다 정확한 설계수문량 산정이 가능하다. 본 연구에서는 모분포 홍수지수모형에서의 미지의 모분포를 비정상성 GEV분포형으로 가정함으로써 각 지점의 비정상성을 고려한 설계수문량을 산정할 수 있는 비정상성 지역빈도해석 기법을 개발하고 그 적용성을 알아보고자 한다. 이를 위해 우리나라 전역에 분포된 10개의 강우관측 지점을 하나의 지역으로 구성하고 이질성척도를 통해 지역동질성을 확인하였다. 먼저, 각 지점의 모분포를 가정하기 위하여 각 지점의 연 최대치 강우자료에 대하여 Mann-Kendall test를 통해 경향성을 확인하였다. 경향성이 없는 지점의 경우 정상성 GEV분포형, 경향성이 나타나는 지점의 경우 다양한 형태의 비정상성 GEV분포형 중 Akaike information criterion을 통해 선정된 비정상성 GEV분포형을 모분포로 가정하고, 모분포 홍수지수모형을 적용하여 확률강우량을 산정하였다. 대상 지역에 대한 모의실험을 통해 비정상성을 고려한 모분포 홍수지수모형의 성능을 지점빈도해석 및 기존의 홍수지수모형과 비교하였으며, 정상성 지역빈도해석 대비 비정상성 지역빈도해석을 통해 산정된 확률강우량의 비교를 통해 그 적용성을 평가하였다.

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A Meta-Analysis on the Effect of Entrepreneurship on the Entrepreneurial Intention: Mediating Effect of Entrepreneur Education (기업가정신이 창업의지에 미치는 영향에 관한 메타분석: 창업교육의 매개효과)

  • Yoon, Byeong seon;Kim, Chun Kyu
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.3
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    • pp.207-221
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    • 2020
  • This study conducted a meta-analysis on the effects of innovation, risk-taking, and enterprising on entrepreneurship. From 2013 to 2020, 392 papers, which were judged as quantitative research from doctoral and master thesis, and academic journals published in Korea were selected as research subjects. 28 duplicates of thesis and thesis are excluded. A total of 52 papers were finally selected, excluding 312 papers that were insufficient to be used as research data because there were no statistical values such as correlation coefficients. For the 52 selected papers, the homogeneity of the variables was first verified. As a result of the homogeneity test, the innovativeness, risk-taking, initiative, and entrepreneurship education all showed great effects on heterogeneity, and the average effect size was analyzed by random effect model. The average effect size analyzed was 0.38 ~ 0.49, and all four variables showed moderate average effect size. As a result of analyzing the average effect size by forest plot, all showed proper results. From the results of funnel plot analysis of entrepreneurship education, published errors were confirmed asymmetric. Research data on entrepreneurship education shows that it cannot represent the whole. It is a structural equation model with entrepreneurship and entrepreneurial intention as a parameter. Iinnovation and risk-taking have an impact on entrepreneurship by taking entrepreneurship education as a parameter. Initiative had an effect on the entrepreneurial intention a business, regardless of entrepreneurship education. In a number of studies, university entrepreneurship education has had an impact on the entrepreneurial intention. It should be changed to entrepreneurship education that combines theory and practice. Entrepreneurship education should be transformed into continuous and field-oriented education.

Numerical Objective Assessment Using Structural Similarity for Diffuse Optical Reconstructed Images (재구성된 광간섭단층 영상의 구조적 유사성을 이용한 수치 목표 평가)

  • Mudeng, Vicky;Choe, Se-woon
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2021.10a
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    • pp.658-660
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    • 2021
  • The work within this study develops an algorithm based on the structural similarity index to assess numerically between reconstructed images with a reference image to separate the homogeneity and heterogeneity for diffuse optical tomography. Global geometry and region of interest assessment have been measured to yield the similarity. The results indicate that the mean of structural similarity index shows potential performance to distinguish between visible and invisible inclusion inside the model. Therefore, the structural similarity index may promise to assist the image assessment for evaluating breast structural information.

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The Effect of Grouping by Students' Agreeableness in Cooperative Learning (협동학습에서 학생의 유화성에 따른 집단 구성의 효과)

  • Han, Jae-Young;Han, Su-Jin;Noh, Tae-Hee
    • Journal of The Korean Association For Science Education
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    • v.22 no.4
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    • pp.717-724
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    • 2002
  • In this study. the effects of grouping by students' agreeableness in cooperative learning strategy applied to middle school science classes on their achievement. confidence, satisfaction, attitude toward science class, and cohesion of group members were investigated. One hundred and fifty-eight students were assigned to control group, homogeneous group and heterogeneous group, and taught about separation of mixture for 7 class hours. The results revealed that there was no significant difference in the achievement test scores. However, significant interaction between the instruction and the level of agreeableness were found in the satisfaction and the cohesion of group members. Students of higher agreeableness level in the homogeneous group were more satisfied with science class and cohesive. Students' attitude toward science class in the homogeneous group was also significantly higher than those in the other groups.

A Study on the Potential Vegetation Recovery according to the Environment and Type of Tunnel Entrance and Exit (고속도로 터널 입·출구부 유형과 주변 환경에 따른 식생복구 잠재성에 관한 연구)

  • Lee, Sang-Cheol;Choi, Song-Hyun;Kim, Dong-Pil;Song, Jae-Tak;Oh, Hyun-Kyung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.6
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    • pp.161-172
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    • 2012
  • The purpose of this study is to classify, evaluate and grade the existing highway tunnels to increase landscape and natural statistics keeping the structural safety about tunnel gates area and induce the ones that will be constructed in the future by drawing the improvements and restoring the techniques as an environment-friendly. To examine the types of tunnel gate area, total 54 tunnels were investigated by selecting Gyeongbu Expressway, Yeongdong Expressway, and Jungang Expressway. Tunnel entrances and exit ports were classified as a Wall-closed type and Protruding type, which is based on tunnel gate type. Vegetation Landscape types were classified as Multilayer-Same as the surrounding landscape_(MS), Multilayer-Difference of surrounding landscape_(MD), Single layer-Same as the surrounding landscape_(SS), Single layer-Difference of surrounding landscape_(SD), and a Desolate type which based on vegetation layers and environment-friendly. Potential vegetation recovery was identified based on the structural stability and revegetation potential of the tunnel. The factors include the structural stability of the slope height and slope gradient were selected. Revegetation potential was identified as a growth potential. This factor was used in the step to classify vegetation recovery potential of a tunnel. The result, which investigated the types of tunnel entrances and exit parts has found that the most typical in 33 places was a Wall closed type with 61.1% of the total ones. The case of vegetation landscape types was created but different from the ones surrounding it with 85.2% of the total ones. It is judged that the currently constructed vegetation of tunnel entrance and exit parts had put convenience on the safety and management before landscape consideration. In addition, tunnel entrance and exit parts with excellent potential for vegetation recovery were all Protruding type. In addition, it is judged that slope stability can easily obtain growth. Therefore, entrance and exist of the highway tunnels, which will be constructed in the future, should reflect location and the result of the natural and ecological survey in design by performing it in advance and their types, which minimize the damage area range, should be applied to the local characteristics suitably. In addition, the ecologically healthy tunnel construction should be done by introducing active vegetation recovery techniques based on its safety.

Regional Frequency Analysis using Nonparametric Kernel Function (비매개변수적 Kernel Function을 이용한 지역빈도해석)

  • Moon, Young-Il;Oh, Tae-Suk;Kim, Jong-Suk;Jeong, Min-Su
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.1492-1496
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    • 2006
  • 수공구조물의 설계에 있어 가중 중요한 변수 중에 하나가 확률 강우량이다. 우리나라의 경우 매개변수적인 지점빈도해석을 통해 확률 강우량을 산정하고 있으나, 최근 들어 지점별 관측자료의 부족으로 인한 지역빈도해석을 수행하여 확률강우량을 산정하고 있는 실정이다. Index Flood 기법이나 L-moment 기법과 같은 기존의 지역빈도해석은 여러 관측 지점에서 관측된 강우자료를 이용하여 매년최대 시간강우량 자료를 추출하여 동질성 분석을 통해 이질성이 없는 것으로 분석된 연최대 강우량을 빈도해석 하여 확률 강우량을 결정한다. 그러나 이와 같은 지역빈도해석은 매개변수적 지점빈도해석과 마찬가지로 적합도 검정에 통과한 다수의 분포형이 선정되는 경우에 어떤 분포형을 사용하느냐 하는 문제점이 발생할 수 있다. 그리고 선정된 여러 강우 관측 지점의 연최대 강우량 자료에 모두 동일한 확률 분포형을 이용하므로 선정된 확률 분포형이 모든 지점의 강우 자료와 적합하지 못할 가능성을 내포하고 있으며, 또한 수문자료가 여러가지 요인으로 인하여 복합분포(mixed distribution)형태를 가질 때, 매개변수적 해석방법으로는 다중 첨두를 갖는 확률밀도함수를 해석하는데는 여러 가지 어려움이 따른다. 따라서 이러한 매개변수적 확률분포형을 이용한 빈도해석의 문제점을 해결할 수 있는 비매개변수적 빈도해석이 하나의 대안으로 제시될 수 있다. 본 연구에서는 강우자료의 선별을 통해 신뢰성 있는 자료를 구축하고, 기존의 매개변수를 갖는 확률 분포형을 이용한 지역빈도해석을 적용하여 확률 강우량을 산정하였다. 그리고 동질성분석을 통해 선정된 강우자료에 대해 비매개변수적 지역빈도해석을 적용하여 확률 강우량을 산정하고 각각의 방법에 대한 빈도해석 결과를 비교하여 확률강우량 해석에 있어 하나의 대안을 제시하고자 한다.X>${\mu}_{max,A}$는 최대암모니아 섭취률을 이용하여 구한 결과 $0.65d^{-1}$로 나타났다.EX>$60%{\sim}87%$가 수심 10m 이내에 분포하였고, 녹조강과 남조강이 우점하는 하절기에는 5m 이내에 주로 분포하였다. 취수탑 지점의 수심이 연중 $25{\sim}35m$를 유지하는 H호의 경우 간헐식 폭기장치를 가동하는 기간은 물론 그 외 기간에도 취수구의 심도를 표층 10m 이하로 유지 할 경우 전체 조류 유입량을 60% 이상 저감할 수 있을 것으로 조사되었다.심볼 및 색채 디자인 등의 작업이 수반되어야 하며, 이들을 고려한 인터넷용 GIS기본도를 신규 제작한다. 상습침수지구와 관련된 각종 GIS데이타와 각 기관이 보유하고 있는 공공정보 가운데 공간정보와 연계되어야 하는 자료를 인터넷 GIS를 이용하여 효율적으로 관리하기 위해서는 단계별 구축전략이 필요하다. 따라서 본 논문에서는 인터넷 GIS를 이용하여 상습침수구역관련 정보를 검색, 처리 및 분석할 수 있는 상습침수 구역 종합정보화 시스템을 구축토록 하였다.N, 항목에서 보 상류가 높게 나타났으나, 철거되지 않은 검전보나 안양대교보에 비해 그 차이가 크지 않은 것으로 나타났다.의 기상변화가 자발성 기흉 발생에 영향을 미친다고 추론할 수 있었다. 향후 본 연구에서 추론된 기상변화와 기흉 발생과의 인과관계를 확인하고 좀 더 구체화하기 위한 연구가 필요할 것이다.게 이루어질 수 있을 것으로 기대된다.는 초과수익률이 상승하지만, 이후로는 감소하므로, 반전거래전략을 활용하는 경우 주식투자기간은 24개월이하의 중단기가 적합함을 발견하였다. 이상의 행태적 측면과 투자성과측면의 실증결과를 통하여 한국주식시장에 있어서 시장수익률을 평균적으로 초과할 수 있는 거래전

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Effects of Death Education Programs among Korean Aged in the Convergence Era: A Systematic Review and Meta-Analysis (융복합 시대 한국 노인의 죽음교육 프로그램 효과: 체계적 문헌고찰 및 메타분석)

  • Kim, Hyunsim;Park, Seurk
    • Journal of Convergence for Information Technology
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    • v.12 no.5
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    • pp.71-82
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    • 2022
  • This study aimed to identify the effects of death education programs among Korean aged on death anxiety and attitudes toward death in the convergence era. The searched kew words were included aged, death education program, death anxiety, and attitudes to death in the research papers published in Korea. Finally, 11 studies were selected and the effect size was calculated. Death anxiety and death attitude were selected as dependent variables, and publication type, total duration of intervention, and frequency of intervention were selected as moderator variables. The total of 11 papers were selected to estimate the effect sizes of interventions. As a result, the overall effect size of the death education program for the aged was 1.07. The overall effect size showed death education program was able to lower death anxiety (Hedges' g=1.30, 95% Cl=0.80~1.80, p<.01) and improve attitudes to death (Hedges' g=0.93, 95% Cl=0.49~1.37, p<.01) compared with the no intervention group. In the moderator analysis to identify the cause of heterogeneity, significant results were found in the frequency of intervention. We propose a study that repeatedly verifies the effect of related studies in the future by providing the theoretical basis and basic data for the development of the death education program.

Effect of Community-based Rehabilitation on Patients with Brain Injury: Meta-analysis Based on the ICF Model (뇌손상 환자의 지역사회재활(CBR) 프로그램의 효과: ICF 모델에 근거한 메타분석)

  • Cha, Yu-Jin;Kim, Se-Yun
    • The Journal of the Korea Contents Association
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    • v.14 no.3
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    • pp.203-214
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    • 2014
  • In this study, a meta-analysis was conducted to investigate the effect of community-based rehabilitation on patients with brain injury by ICF factor in previous studies and examine the application of recent community-based rehabilitation program. Total 15 articles that satisfied the selection criteria were divided by ICF factors to obtain the effect size. Homogeneity and publication bias were tested for those selected papers. As a result, the overall effect size of community-based rehabilitation was 0.22; the effect size by physical function and structure among the ICF factors came to be 0.21; and the effect size of activity and participation was 0.20, indicating a small effect size. The studies involved in a meta-analysis were considered as the absence of heterogeneity and publication bias, which indicates that the results of this study are subjectively reliable. These results well explained the level of change on ICF factors, especially physical function and structure, activity and participation, in other words, the intervention effect of community-based rehabilitation on patients with brain injury.