• Title/Summary/Keyword: model studies

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Perceptions and Perspectives of Secondary Science Teachers on Core Concepts (핵심 개념에 대한 중등 과학 교사들의 인식 및 관점)

  • Eun-Jeong Yu
    • Journal of the Korean earth science society
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    • v.44 no.1
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    • pp.47-61
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    • 2023
  • Rather than an abstract discourse, the purpose of this study is to outline the core concepts in the 2015 revised curriculum as a concrete teaching and learning method in the school context. We interviewed eight secondary science teachers and reported their perceptions and perspectives on core concepts using a backward design model based on the cyclical process of the platform, deliberation, and design for developing teaching and learning materials to understand core concepts. The participants perceived these core concepts differently, such as big ideas corresponding to the ultimate principle, minimum science concepts required for daily life, and primary and significant key concepts. In addition, this affects the association of teaching and learning. When core concepts are understood as transferable and expandable big ideas, there is a tendency to focus on the relationship between concepts and design project learning in a specific direction. However, if core concepts are identified as minimum science concepts at the level of science literacy, that can be recalled within the context of life, there is a tendency to emphasize on activities that make a meaningful difference to the lives of students with focus on case studies that are relevant to everyday life. Once core concepts are identified as key scientific content elements, such as basic or significant concepts, teachers recognize that it is essential to emphasize concept changes by correcting misconceptions, acquiring accurate scientific knowledge, and developing problem-solving items through paper-and-pencil evaluation. As the 2015 revised curriculum is finalized and the 2022 revised curriculum is scheduled for release, effective policy support is required to ensure that the curriculum is revised, which emphasizes the purpose of big ideas by naming core concepts as core ideas, to be stably implemented in schools.

The Effect of Convergence Reading Education on the Convergence Literacy of Adolescents: Focusing on the Mediating Effect of Learning Motivation (융합독서교육이 청소년의 융합적 소양에 미치는 영향 - 학습동기의 매개효과를 중심으로 -)

  • Soo-Youn Cho;Miah Cho
    • Journal of the Korean Society for Library and Information Science
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    • v.57 no.2
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    • pp.151-178
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    • 2023
  • The purpose of this study is to investigate the effect of school library reading classes on the convergence literacy of adolescents based on the convergence reading education model. To achieve this, elements of convergence education for future-oriented competence were derived from the level of reading education based on previous studies and literature, and the effectiveness of education was measured by conducting a convergence literacy test targeting 50 general high school students. In this study, reading classes and tests were conducted over 12 sessions from April 2022 to November 2022, and the study participants were divided into two groups, and convergence reading education and self-reading education were applied respectively. The analysis results of this study are as follows. First, It was verified that there was a significant difference in the promotion of convergent literacy of adolescents according to the method of reading education. Second, it was verified that convergence reading education had a significant effect on convergence literacy of adolescents such as convergence, creativity, self-direction and communication ability. Third, as a result of verifying whether learning motivation plays a mediating role in convergence reading education influencing convergent literacy, learning motivation played a partial mediating role and had an indirect effect on creativity, self-direction, and communication ability between convergence reading education and convergence literacy, but showed no significant mediating effect on convergence ability.

Developing Integrated Transportation Service Index for Encouraging Transit-oriented Development (TOD형 개발 촉진을 위한 통합교통서비스 지표의 개발)

  • Hwang, Kee Yeon;Shin, Sang Young;Cho, Yong Hak;Sohn, Kee Min
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1D
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    • pp.1-10
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    • 2008
  • Recently, the Seoul Metropolitan Government (SMG) has initiated several urban redevelopment projects to revitalize the downtown well equipped for transit oriented development (TOD). Since, TOD should incur higher density development in our context, it has negative impacts on travel patterns, congestion, and urban environmental quality. The purpose of this study is to develop new transportation service index which can facilitate higher density TOD. This study includes relevant foreign case studies, the development of multimodal transportation index, and the impact analysis of TOD when it is applied in the downtown Seoul. In chapter III, it developed a so-called ITLOS, new multimodal transportation service index which shows the possibility of accommodating further development by integrating roadway service index with public transportation service index. The study sets ten policy scenarios by varying densities, and run the Seoul Congestion Management Model (SECOMM) to estimate the sustainable transportation impacts of TOD in the downtown. Travel speed index that only represents the availability of road capacity for development reveal that higher density development in the downtown can deteriorate traffic congestion while improving region-wide transportation level of service in Seoul. Also, it is proved that higher density development is more feasible when using ITLOS as the index because it considers not only available road capacity but subway capacity in the analysis area.

Impact of Drag-Related Weighting Coefficients in Vegetated Open-Channel Flows (식생된 개수로에서 항력가중계수가 흐름에 미치는 영향 분석)

  • Kang, Hyeongsik;Choi, Sung-Uk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.5B
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    • pp.529-537
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    • 2006
  • This paper investigates the impacts of the drag-related weighting coefficients on mean velocity and turbulence structures. The transport equations for the Reynolds stress of vegetated open-channel flows are derived by using the temporal- and horizontal-averaging scheme. It is found that the total Reynolds stress of vegetated open channel flows consists of the Reynolds stress due to temporally fluctuating velocities and the Reynolds stress due to spatially fluctuating velocities. The drag-related weighting coefficient $C_{fk}$ for the total Reynolds stress component is found to be unit, while the coefficient for the Reynolds stress due to temporally fluctuating velocities can be negligible. This is the reason why very small weighting coefficients in previous studies yield very good agreements with measured data. In other words, the Reynolds stress due to spatially fluctuating velocities remains still unknown, especially due to the large number of measuring locations. Through a developed Reynolds stress model, vegetated open-channel flows are simulated and compared with measured data from the literature. Comparisons reveal that the computed mean flow and Reynolds stress structures are hardly affected by the drag-related weighting coefficients. However, the computed turbulence intensity profiles are significant different with the drag-related weighting coefficients. A budget analysis of the transport equations for the Reynolds stress component is carried to investigate why turbulence intensity is affected by the drag-related weighting coefficients.

Differences between Sale Prices and Lotting Prices in New Multi-family Housing Considering Housing Sub-Market (주택하부시장 특성을 고려한 신규 분양가와 입주후 가격 변화에 관한 연구)

  • Choi, Yeol;Kim, Hyung Soo;Park, Myung Je
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.4D
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    • pp.523-531
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    • 2008
  • This study tried to find differences between housing lotting prices and sale prices owing to new multi-family housing price regulation. As the results of this study, they are as follows; First, this study shows housing market in Busan has a preferences of new housing which has a new housing form differing from the existing housing form. For example, the mixed-use apartment with higher stories shows steeper incline than the apartments with the existing forms. Second, the new housing prices are affected by the information that affect the price of the old existing housing. They are rates of green area of an apartment complex, the number of household, accessibility to downtown Busan and etc.. They are also confirmed factors that affect a rise of used-housing price in other studies. Third, brand value of apartments affects new housing prices. For example, if the major construction companies build the new apartment, it shows a rising trend than any other housing. Therefore, the local construction companies are expected to be put on a disadvantage places than major construction companies. Fourth, the lotting prices are the most important cause that lead to rise the new housing prices. Accordingly, the present lotting prices are expected that upward tendency the purchasing prices of the new housing will not continue, because the lotting prices have risen since the government removed lotting price regulations and exceeded the level of used-housing prices. And it denote that importance of housing sub-market which indicates rates of old existing housing market rising, frist preference Gu, second preference Gu, rate of multi-family housing.

Assessment of Visual Landscape Image Analysis Method Using CNN Deep Learning - Focused on Healing Place - (CNN 딥러닝을 활용한 경관 이미지 분석 방법 평가 - 힐링장소를 대상으로 -)

  • Sung, Jung-Han;Lee, Kyung-Jin
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.3
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    • pp.166-178
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    • 2023
  • This study aims to introduce and assess CNN Deep Learning methods to analyze visual landscape images on social media with embedded user perceptions and experiences. This study analyzed visual landscape images by focusing on a healing place. For the study, seven adjectives related to healing were selected through text mining and consideration of previous studies. Subsequently, 50 evaluators were recruited to build a Deep Learning image. Evaluators were asked to collect three images most suitable for 'healing', 'healing landscape', and 'healing place' on portal sites. The collected images were refined and a data augmentation process was applied to build a CNN model. After that, 15,097 images of 'healing' and 'healing landscape' on portal sites were collected and classified to analyze the visual landscape of a healing place. As a result of the study, 'quiet' was the highest in the category except 'other' and 'indoor' with 2,093 (22%), followed by 'open', 'joyful', 'comfortable', 'clean', 'natural', and 'beautiful'. It was found through research that CNN Deep Learning is an analysis method that can derive results from visual landscape image analysis. It also suggested that it is one way to supplement the existing visual landscape analysis method, and suggests in-depth and diverse visual landscape analysis in the future by establishing a landscape image learning dataset.

Estimation of Displacement Response from the Measured Dynamic Strain Signals Using Mode Decomposition Technique (모드분해기법을 이용한 동적 변형률신호로부터 변위응답추정)

  • Chang, Sung-Jin;Kim, Nam-Sik
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.4A
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    • pp.507-515
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    • 2008
  • In this study, a method predicting the displacement response of structures from the measured dynamic strain signal is proposed by using mode decomposition technique. Evaluation of bridge stability is normally focused on the bridge completed. However, dynamic loadings including wind and seismic loadings could be exerted to the bridge under construction. In order to examine the bridge stability against these dynamic loadings, the prediction of displacement response is very important to evaluate bridge stability. Because it may be not easy for the displacement response to be acquired directly on site, an indirect method to predict the displacement response is needed. Thus, as an alternative for predicting the displacement response indirectly, the conversion of the measured strain signal into the displacement response is suggested, while the measured strain signal can be obtained using fiber optic Bragg-grating (FBG) sensors. As previous studies on the prediction of displacement response by using the FBG sensors, the static displacement has been mainly predicted. For predicting the dynamic displacement, it has been known that the measured strain signal includes higher modes and then the predicted dynamic displacement can be inherently contaminated by broad-band noises. To overcome such problem, a mode decomposition technique was used. Mode decomposition technique estimates the displacement response of each mode with mode shape estimated to use POD from strain signal and with the measured strain signal decomposed into mode by EMD. This is a method estimating the total displacement response combined with the each displacement response about the major mode of the structure. In order to examine the mode decomposition technique suggested in this study model experiment was performed.

Assessing the Habitat Potential of Eurasian Otter (Lutra lutra) in Cheonggye Stream Utilizing the Habitat Suitability Index (서식지 적합성 지수를 이용한 청계천 수달의 서식지 평가)

  • In-Yoo Kim;Kwang-Hun Choi;Dong-Wook W. Ko
    • Korean Journal of Environment and Ecology
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    • v.37 no.2
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    • pp.140-150
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    • 2023
  • The Eurasian otter (Lutra lutra) is an apex predator of the riparian ecosystem. It is a keystone and an indicator species; consequently, its presence suggests a sustainable water environment. Otter is a keystone species as a predator at the top of the food web in the aquatic environment and an indicator species representing the health of the aquatic environment. Although Eurasian otters disappeared from the Han River urban water system because of anthropogenic activities like habitat destruction, poaching, and environmental pollution in the 1980s, the species were sighted in the Cheonggye Stream, Jungrang Stream, and Seongnae Stream, which are urban sections of the Han River, in 2016 and 2021. Therefore, it is pertinent to assess the habitat potential in the area for conservation and management measures to ensure its permanent presence. However, existing studies on otter habitats focused on natural rivers and reservoirs, and there is a limit to applying them to habitats artificially confined habitats in narrow spaces such as tributaries in urban areas of the Han River. This study selected the Cheonggye Stream, an artificially restored urban stream, to evaluate its potential as a habitat for Eurasian otters in urban water environments using the habitat suitability index (HSI). The HSI was calculated with selected environment attributes, such as the cover, food, and threat, that best describe the L. lutra habitat. According to the results, the confluence area of Seongbuk Stream and Cheonggye Stream and the confluence area of Cheonggye Stream and Jungnang Stream were suitable otter habitats, requiring appropriate conservation efforts. The HSI model suggests a valuable method to assess the habitat quality of Eurasian otters in urban water environments. The study is crucial as it can help rehabilitate the species' populations by identifying and managing potential Eurasian otter habitats in highly urbanized areas of the Han River basin and its tributaries.

Nonlinear Analysis of CFT Truss Girder with the Arch-shaped Lower Chord (아치형상의 하현재를 갖는 CFT 트러스 거더의 재료 비선형 해석)

  • Song, Na-Young;Choung, Chul-Hun;Kim, Young-Jin
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.6A
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    • pp.625-639
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    • 2009
  • Experimental and analytical studies are performed on the mechanical behavior of concrete-filled tubular(CFT) truss girders for different f/L ratios. Bending tests are conducted on two CFT truss girder specimens to determine fundamental structural characteristics such as the strength and deformation properties. Nonlinear material models for CFT members subjected to an axial compressive force are compared in this paper by using the nonlinear finite element program, ABAQUS. Previous researchers have proposed several nonlinear stress-strain models of confined concrete. In this study, the nonlinear analyses are performed applying several stress-strain models for confined concrete proposed by Mander, Sakino, Han, Susantha and Ellobody, and the results are compared with the experimental results in terms of load-deflection and load-strain relationships. Based on the comparisons of the load-deflection relationships, the models proposed by Mander and Susantha provide a maximum load about 12.0~13.8% higher and that by Sakino gives a maximum load about 7.6% higher than the experimental results. The models proposed by Han and Ellobody give a maximum load only about 0.2~1.2% higher than the test results, showing the best agreement among the proposed stress-strain models. However, the load-strain relations predicted by the existing models generally provide conservative results exhibiting larger strains than the experimental data.

A Study on the Classification Model of Overseas Infringing Websites based on Web Hierarchy Similarity Analysis using GNN (GNN을 이용한 웹사이트 Hierarchy 유사도 분석 기반 해외 침해 사이트 분류 모델 연구)

  • Ju-hyeon Seo;Sun-mo Yoo;Jong-hwa Park;Jin-joo Park;Tae-jin Lee
    • Convergence Security Journal
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    • v.23 no.2
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    • pp.47-54
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    • 2023
  • The global popularity of K-content(Korean Wave) has led to a continuous increase in copyright infringement cases involving domestic works, not only within the country but also overseas. In response to this trend, there is active research on technologies for detecting illegal distribution sites of domestic copyrighted materials, with recent studies utilizing the characteristics of domestic illegal distribution sites that often include a significant number of advertising banners. However, the application of detection techniques similar to those used domestically is limited for overseas illegal distribution sites. These sites may not include advertising banners or may have significantly fewer ads compared to domestic sites, making the application of detection technologies used domestically challenging. In this study, we propose a detection technique based on the similarity comparison of links and text trees, leveraging the characteristic of including illegal sharing posts and images of copyrighted materials in a similar hierarchical structure. Additionally, to accurately compare the similarity of large-scale trees composed of a massive number of links, we utilize Graph Neural Network (GNN). The experiments conducted in this study demonstrated a high accuracy rate of over 95% in classifying regular sites and sites involved in the illegal distribution of copyrighted materials. Applying this algorithm to automate the detection of illegal distribution sites is expected to enable swift responses to copyright infringements.