• Title, Summary, Keyword: 이질성검증

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Nonlinear Consolidation Analysis Considering Radial Drainage (수평배수를 고려한 비선형 압밀해석)

  • Lee, Song;Chae, Young-Su;Hwang, Koou-Ho;Jeon, Je-Sung
    • Journal of the Korean Geotechnical Society
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    • v.16 no.6
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    • pp.105-115
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    • 2000
  • 본 연구는 현실에 부합하는 연약지반의 압밀거동을 예측하기 위한 연구로서, 일단 3차원 배수 조건하에서 지반의 자중 및 압축성과 투수성의 비선형적 성질이 고려된 비선형 압밀모델을 구성하였다. 또한 연직 배수재의 시공과정에서 발생할수 있는 지반의 교란현상 및 다양한 이질층의 구성, 점증적인 하중재하 조건, 연직배수재의 부분관입 조건에 대한 고려가 가능하도록 비선형 압밀모델을 수정, 보완하였다. 이상의 연구결과를 바탕으로 유한차분방법에 의한 수치해석을 실시하였고 최종적으로 각종 희귀분석과정을 도입한 3차원 비선형 압밀해석 프로그램을 개발하였다. Ska-Edeby의 시험시공 사례를 통한 개발 프로그램의 검증을 실시하였는데, 시험시공 사례의 경우, 현장에서 측정한 깊이별 침하량 및 간극수압 결과를 개발 프로그램에 의한 예측결과와 비교, 분석하였다. 또한 개발 프로그램을 이용하여 다층지반 해석과 관련된 기존 해석방법의 문제점 및 지반의 교란효과와 연직배수재의 부분관입조건, 점증적인 하중재하 조건등이 지반의 압밀거동에 미치는 영향에 대해 살펴보았다.

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Genetic differences between Korean-Japanese and Chinese-Taiwanese Dendrobium moniliforme (L.) Sw. (한국-일본과 중국-대만 석곡의 유전적 차이)

  • Kim, Young-Kee;Kang, Kyung-Won;Kim, Ki-Joong
    • Korean Journal of Plant Taxonomy
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    • v.45 no.2
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    • pp.145-157
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    • 2015
  • The nucleotide sequences of nuclear ribosomal ITS regions and chloroplast rbcL, matK and psbA-trnH regions of 30 individuals of Dendrobium moniliforme from several localities in four countries and 28 related species of Dendrobium were compared to investigate the genetic differences among Korean, Japanese, Taiwanese and Chinese D. moniliforme, and to verify the homogeneity of D. moniliforme, which is used as a traditional medicine in East Asia. A phylogenetic analysis showed that Korean D. moniliforme and Japanese D. moniliforme form a monophyletic group, with no significant differences between their nucleotide sequences. This confirms that they are the same species. However, the Chinese and Taiwanese D. moniliforme were polyphyletic. Various species related to D. moniliforme were located between the Korean-Japanese D. moniliforme and the Chinese-Taiwanese D. moniliforme, and other related species were found between individuals of Chinese-Taiwanese D. moniliforme. D. moniliforme is described in Japan, providing evidence that the Korean-Japanese D. moniliforme is the original species. In addition, our data suggest that the Chinese-Taiwanese D. moniliforme complex is a mixture of a range of other species. Further studies are required to understand the taxonomic identity of this species. In the Korean-Japanese D. moniliforme, there were almost no genetic differences among the localities, whereas the genetic heterogeneity was high among individuals of the Chinese-Taiwanese D. moniliforme.

The Effects of Project Method on Children's Academic Achievement on the Unit of Growing Flowers and Vegetables in Practical Arts (초등학교 실과 '꽃과 채소 가꾸기' 단원에서 프로젝트법이 학업 성취도에 미치는 효과)

  • Bak, Heyoung-Seo;Cho, Sung Min
    • Journal of vocational education research
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    • v.29 no.3
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    • pp.107-132
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    • 2010
  • The purpose of this study was to investigate the effects of learning achievement by comparing project approach group and the control group on the unit of growing flowers and vegetables in practical arts education. For this purpose, the experimental study on the unit of growing flowers and vegetables was achieved with 63 students(5th grade 2 classes) in S elementary school. The project approach model (Chung, Sung-bong) was applied to the experimental group, and the traditional model to the control group. To verify the effects of each class, nonequivalent control group post test-only design was applied 10 times. The SPSSWIN(ver 12. 0. 1) was used for analyzing the frequency and t-tests. The results of this study were as follows ; First, there was significant effect of learning achievement(cognitive domain) in the project approach groups. In addition, learning achievement of the experimental group has been showed significant difference about intellectual function and ability but not about knowledge. Second, there was significant effect of learning achievement(psychomotor domain) in the project approach groups. In other words, there has been showed significant difference in basic skill and integrated skill for growing flowers and vegetables but not in elemental skill for planting. Third, as the post test, there existed significant effect(affective domain) in the project approach groups. In other words, there was a meaningful difference in acceptance, value, belief, actualization but not in interest. Based on these results, It is believed that the project approach model in the unit of 'growing flowers and vegetables' is more effective than the traditional learning method in learning achievement of learners' cognitive, psychomotor and affective domain.

A Model for Effective Customer Classification Using LTV and Churn Probability : Application of Holistic Profit Method (고객의 이탈 가능성과 LTV를 이용한 고객등급화 모형개발에 관한 연구)

  • Lee, HoonYoung;Yang, JooHwan;Ryu, Chi Hun
    • Journal of Intelligence and Information Systems
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    • v.12 no.4
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    • pp.109-126
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    • 2006
  • An effective customer classification has been essential for the successful customer relationship management. The typical customer rating is carried out by the proportionally allocating the customers into classes in terms of their life time values. However, since this method does not accurately reflect the homogeneity within a class along with the heterogeneity between classes, there would be many problems incurred due to the misclassification. This paper suggests a new method of rating customer using Holistic profit technique, and validates the new method using the customer data provided by an insurance company. Holistic profit is one of the methods used for deciding the cutoff score in screening the loan application. By rating customers using the proposed techniques, insurance companies could effectively perform customer relationship management and diverse marketing activities.

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A Study on Effectiveness of STEM Integration Education Using Educational Robot (교육용 로봇을 활용한 STEM 통합교육의 효과성 연구)

  • Song, Jeong-Beom;Shin, Soo-Bum;Lee, Tae-Wuk
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.6
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    • pp.81-89
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    • 2010
  • The purpose of this research is to verify the influence of STEM integrate education using educational robots on improvement of the level of attitude towards Mathematics. The following hypothesis was formulated in order to achieve this purpose: There will be a meaningful difference in the level of attitude towards Mathematics between elementary school students educated by STEM integrated education with robots and by the traditional method of teaching Mathematics. To prove this hypothesis, 56 of first grade students were tested under the nonequivalent control group in the pretest-posttest designs. As a result of the study, it is showed that STEM integrated education has a positive effect on promoting the level of elementary school students' attitude towards Mathematics. Therefore, we need the instructional activities which can combine the knowledge gained from a variety of curriculum with activities by using educational robots.

A Study on the Haptic Control Technology for Unmanned Military Vehicle Driving Control (무인차량 원격주행제어를 위한 힘반향 햅틱제어 기술에 관한 연구)

  • Kang, Tae-Wan;Park, Ki-Hong;Kim, Joon-Won;Kang, Seok-Won;Kim, Jae-Gwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.12
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    • pp.910-917
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    • 2018
  • This paper describes the developments to improve the feeling and safety of the remote control system of unmanned vehicles. Generally, in the case of the remote control systems, a joystick-type device or a simple steering-wheel are used. There are many cases, in which there are operations without considering the feedback to users and driving feel. Recently, as the application area of the unmanned vehicles has been extended, the problems caused by not considering the feedback are emphasized. Therefore, the need for a force feedback-haptic control arises to solve these problems. In this study, the force feedback-haptic control algorithm considering the vehicle parameters is proposed. The vehicle parameters include first the state variables of dynamics, such as the body side-slip angle (${\beta}$) and yawrate (${\gamma}$), and second, the parameters representing the driving situations. Force feedback-haptic control technology consists of the algorithms for general and specific situations, and considers the situation transition process. To verify the algorithms, a simulator was constructed using the vehicle dynamics simulation tool with CAN communication environment. Using the simulator, the feasibility of the algorithms was verified in various scenarios.

An Experimental Study on a Network-based Collaborative Learning System for Education of Information Ethics (정보통신윤리 교육을 위한 네트웍 기반 협력학습 시스템에 대한 실험 연구)

  • Song, Tae-Ok;Jung, Sang-Wuk;Kim, Tae-Young
    • The Journal of Korean Association of Computer Education
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    • v.4 no.2
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    • pp.63-69
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    • 2001
  • In this paper, the educational effects of NETCLASS(network-based collaborative learning system) for EICE(education on information communication ethics) were verified by a non-equivalent control group protest-posttest design. We experimented our system on an experimental group (45 learners) and a comparative group (45 learners) respectively with a defining issues test (DIT). The t-value is 5.108 which shows the difference of the mean value between the experimental group and the comparative group, and their average p-mark shows that the difference is statistically meaningful at p<.001 level. Thus, the experiment using NETCLASS and DIT suggests that the morality of the experimental group is higher than that of the comparative group(t(88)=+5.108, p<.001). This paper suggests very strong possibility that the abilities such as creativity, sociality, morality and emotivity can be improved by utilizing ICT(Information and Communication Technology).

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Development of rainfall quantile projection technique based on regional frequency analysis (지역빈도해석에 의한 미래 확률강우량 전망 기법의 개발)

  • Nam, Woo-Sung;Um, Myoung-Jin;Ahn, Hyun-Jun;Heo, Jun-Haeng
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.335-335
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    • 2012
  • 기후변화에 의한 미래 수문량 전망에 대한 연구는 전지구 모델 결과를 바탕으로 이루어진다. 현재 전지구 모델의 모의 결과 생산된 강우 자료는 기상청에서 제공되며, 제공된 자료는 기상청 관측 지점에 국한되어 있다. 어떤 유역의 확률홍수량 전망은 유역내 강우 지점의 확률강우량을 강우-유출 모형인 HEC-1에 입력하여 추정할 수 있다. 한강 유역과 같은 대유역의 확률홍수량을 구하기 위해서는 유역내 기상청 관측 지점만으로는 지점수가 부족하기 때문에 국토해양부나 수자원공사 관할의 지점 자료를 활용한다. 하지만 이러한 대유역의 미래 확률홍수량을 전망하고자 하는 경우에 제공되는 전지구 모델 결과가 기상청 지점에 국한되어 있어 다른 지점의 확률강우량을 산정하는 데 어려움이 있다. 본 연구에서는 이러한 문제를 보완하기 위해 지역빈도해석을 이용하여 미래 전망 자료가 없는 지점들의 확률강우량을 추정하였다. 지역빈도해석을 수행하기 위해서는 관측 자료가 있는 유역내 지점들의 특성치(site characteristics)를 바탕으로 지역을 구분하고, Hosking and Wallis(1997)가 제안한 이질성 척도(heterogeneity measure)를 근거로 구분된 지역의 수문학적 동질성 여부를 검토하며, 각 지역에 대한 성장곡선(growth curve)를 추정한다. 지역별로 추정된 성장곡선에 지점의 연최대값 평균을 곱하면 그 지점의 확률강우량을 추정할 수 있다. 따라서 미래 기간의 지역별 성장곡선과 지점의 연최대값 평균을 전망할 수 있으면, 미래 기간의 지점별 확률강우량을 산정할 수 있고, 이를 바탕으로 확률홍수량도 전망할 수 있다. 이를 위해 본 연구에서는 전지구 모델에서 모의된 강우 자료를 바탕으로 미래 기간의 성장곡선을 추정하고, 과거 대비 미래 기간의 지속기간별 연최대값 평균의 비율을 산정하여 모의 자료가 없는 지점에 적용함으로써 미래 기간의 연최대값 평균을 산정하였으며, 이를 바탕으로 미래 기간의 확률강우량을 산정하도록 하였다. 이 기법의 신뢰도를 검증하기 위해 관측 자료를 두 기간으로 구분하여, 이 기법을 적용하여 추정한 확률강우량과 관측 자료로부터 산정한 확률강우량을 비교하였다.

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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.

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The Effect of Grouping by Communication Apprehension Level in Paired Think-Aloud Problem Solving for Middle School Chemistry (중학교 화학에 적용한 해결자.·청취자 활동에서 의사소통 불안 수준에 따른 소집단 구성의 효과)

  • Kang, Hun-Sik;Lee, Jeong-Soon;Kim, Kyung-Sun;Jeon, Kyung-Moon;Noh, Tae-Hee
    • Journal of the Korean Chemical Society
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    • v.51 no.6
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    • pp.569-576
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    • 2007
  • In this study, the effect of grouping by communication apprehension level in paired think-aloud problem solving was examined. Three classes of 9th graders (N=99) were randomly assigned to a control group, homogeneous group or heterogeneous group based on the test scores of their communication apprehension. After the instructions concerning ‘writing balanced chemical equation', ‘the law of conservation of mass', and ‘the law of definite proportions' for 7 class hours, students' chemistry problem solving ability and the perception to the paired think-aloud problem solving were examined. Two-way ANOVA results revealed that there was an interactive effect in the score of chemistry problem solving ability test. In simple effect test for the students of low communication apprehension, the scores of the heterogeneous group were found to be significantly higher than those of the control group. However, the students in homogeneous group had relatively positive perceptions to the paired think-aloud problem solving.