• 한국과학교육학회:학술대회논문집
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• 2008.08a
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• pp.103.1-103.1
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• 2008

• Journal of Korean Society of Transportation
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• v.23 no.6 s.84
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• pp.91-102
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• 2005

When it comes to the process of information storage, people are likely to organize individual information into the forms of groups rather than independent attributes, and put them together in their brains. Likewise, in case of finding the shortest path, this study suggests that a Hierarchical Road Network(HRN) model should be selected to browse the most desirable route, since the HRN model takes the process mentioned above into account. Moreover, most of drivers make a decision to select a route from origin to destination by road hierarchy. It says that the drivers feel difference between the link travel tine which was measured by driving and the theoretical link travel time. There is a different solution which has predicted the link travel time to solve this problem. By using this solution, the link travel time is predicted based on link conditions from time to time. The predicated link travel time is used to search the shortest path. Stochastic Process model uses the historical patterns of travel time conditions on links. The HRN model has compared favorably with the conventional shortest path finding model in tern of calculated speeds. Even more, the result of the shortest path using the HRN model has more similar to the survey results which was conducted to the taxi drivers. Taxi drivers have a strong knowledge of road conditions on the road networks and they are more likely to select a shortest path according to the real common sense.

• Science of Emotion and Sensibility
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• v.9 no.spc3
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• pp.209-224
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• 2006

Hierarchy which is often named as the tree-structure is used to reduce complexity and show primitive structures of complicated information. This paper aims at explaining information-visualization methods using hierarchies in multimedia domains and prospecting the possible applications by examining how they affect the user's tasks involved in information-seeking activities. As a result, four types of information visualization methods named Treemap, Hyperbolic, Cone Tree and DOI Tree employed in multimedia domain, are presented and pros and cons of each method are explained in this paper. Another important part is defining the core tasks and other related-tasks in information-seeking activities, such as, overview, zoom, filter, details-on-demand, relate, history, and extract. Followings are major findings. Treemap uses 'overview' as the core task, which makes user to gain a overall meaning of the whole information cluster. Hyperbolic and DOI Tree apply 'Boom' task through the function of focus+context or by the function of meaningful scaling to magnify or downsize each node. Cone Tree, also, makes the information organizer to classify the patterns of information acquired in the process of users' information-seeking activities by using 'extract' task. Through this study, it is finally found out that the information-visualization methods using hierarchies in multimedia domains should incorporate the wide variety of functional needs related to users' information-seeking behaviors beyond the visual representation of information.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.469-476
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• 2011

The purposes of research is to understand the need of and the effectiveness of multilevel model to evaluate community support program in watershed areas. If the properties of policy target have hierarchical characteristics, the multilevel analysis is an adequate method to evaluate and test the effectiveness of policy. Also, the technique of multilevel modeling is extended to testing the relevance between performance appraisal and policy effectiveness. The case study of watershed region's community support program was estimated using satisfaction and economic aid level of policy target. This research has three results. First, the multilevel analysis should be used in nested data structure to estimate the effect of policy intervention. Second, the indexes of multilevel modeling should be used complementally to that of the traditional index approach. Third, the spatial hierarchical structure should be considered as the hierarchical structure in policy evaluation.

• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.935-946
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• 2016

In this paper, we analyzed wage determinants of the vocational high school graduates utilizing both individual-level and work region-level variables. We formulate the models in the way wage determination has multi-level structure in the sense that individual wage is influenced by individual-level variables (level-1) and work region-level (level-2) variables. To incorporate dependency between individual wages into the model, we utilize hierarchical linear model (HLM). The major results are as follows. First, it is shown that the HLM model is better than the OLS regression models which do not take level-1 and level-2 variables simultaneously into account. Second, random effects on sex, maester dummy and engineering dummy variables are statistically significant. Third, the fixed effects on business hours and mean wage of regular job for level-2 variables are statistically significant effect individual-level wages. Finally, parental education level, parental income, number of licenses and high school grade are statistically significant for higher individual-level wages.

• Journal of The Korean Association For Science Education
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• v.35 no.5
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• pp.857-870
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• 2015

Concerning elementary school science subject electric circuit units, which are regarded as difficult by teachers and students, this study aims to use the knowledge state analysis method along with interviews to analyze the knowledge state and hierarchy of inquiry abilities. Before and after applying the electric circuit inquiry abilities module, the question items aimed at assessing the basic inquiry abilities and integrative inquiry abilities for electric circuits were presented to students, and their knowledge state was analyzed along with interviews. Through analysis of the knowledge structure and hierarchy of inquiry abilities about electric circuits, the way of thinking of teachers who taught inquiry abilities, and the way of thinking of students were found to be visually different from each other, and this is an important factor that should not be neglected in the process of teaching and learning about inquiry abilities and should be considered. In addition, the presentation of the knowledge state of and hierarchical relations between inquiry abilities factors can offer implications for guidance on students' learning about inquiry abilities.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.5 no.4
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• pp.35-49
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• 2010

The purpose of this study is to help the venture business innovate the purchasing process. This study reviewed the types of transaction governance structure, and researched the change of transaction governance structure, while using information technology. According to transaction cost theory, the transaction governance structure can be moved from hierarchy to market. It can be moved to the middle, because of economies of scale, incentive for supplier, and increasing search cost. And it can be moved from market exchange to relational exchange, using electronic marketplace. In order to innovate the purchasing process, the venture business can select the transaction governance structure that fits the its purchasing contexts.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.999-1004
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• 1995

본 논문에서는 현재 수행 중인 Hualien 대형내진모델시험 프로젝트의 연구 과제 중의 강제 진동 해석 및 지진 응답 해석을 수행하기 위계서 Hyperelement를 사용한 지반-구조물 상호작용 해석에 대한 절차 및 방법을 연구하였다. Hualien 대형내진모델시험에서 이미 수행된 뒷채움 후 강제 진동 시험의 예 측 및 예측후 해석을 수행하였고, 지진 응답 해석을 위해서는 Hualien부지에서의 자유장해석을 통하여 입력 지반 운동을 결정하여 구조물에서의 지진 응답을 구하였다.

• The Journal of Korean Association of Computer Education
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• v.7 no.3
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• pp.57-66
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• 2004

The purpose of this study is to determine the relationship among the hypermedia structure(hierarchical and network), learner's cognitive style(field-independent and field-dependent), and learning performance in the elementary school. 128 students(4th graders) having field-independent and field-dependent cognitive style were randomly allocated into hierarchical and network structures of hypermedia learning program. There was not significant interaction between hypermedia structure and cognitive style in learning performance. The students in the hierarchical hypermedia structure showed higher learning performance than ones in the network hypermedia structure. Field-independent students significantly got higher results than field-dependent ones. It is concluded that instructional designers should consider hypermedia structure, learner's cognitive style, and learning outcomes when they plan and design hypermedia learning program.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.2
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• pp.12-28
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• 2019

Road geometry is one of the many factors that cause crashes, but the effect on traffic accident depends on weather conditions even under the same road geometry. This study identifies the variables affecting the crash severity by matching the highway accident data and weather data for 14 years from 2001 to 2014. A hierarchical ordered Logit model is used to reflect the effects of road geometry and weather condition interactions on crash severity, as well as the correlation between individual crashes in a region. Among the hierarchical models, we apply a random intercept model including interaction variables between road geometry and weather condition and a random coefficient model including regional weather characteristics as upper-level variables. As a result, it is confirmed that the effects of toll, ramp, downhill slope of 3% or more, and concrete barrier on the crash severity vary depending on weather conditions. It also shows that the combined effects of road geometry and weather conditions may not be linear depending on rainfall or snowfall levels. Finally, we suggest safety improvement measures based on the results of this study, which are expected to reduce the severity of traffic accidents in the future.