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Study on the Environmental Quality Assessment of River Revetment Technique by Life-Cycle-Assessment (전과정 평가에 의한 하천 호안 공법의 환경성 평가에 관한 연구)

  • Kim, Kook-Il;Ahn, Won-Sik
    • Journal of Korea Water Resources Association
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    • v.40 no.6 s.179
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    • pp.485-494
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    • 2007
  • This study was performed to evaluate the environmental qualities of the revetment construction methods and the river-facility materials using Life-Cycle-Assessment(LCA) for the nature-friendly design of close-to-nature river, The investigation results on the environmental qualities of energy and materials used to the close-to-nature river plan showed that the environmental impacts per unit weight increased in the order of gasoline > diesel > cement > wood. The environmental impacts per unit area of revetment construction method exhibited that the environmental loadings increased in the order of gabion > revetment > cribwork. In addition, it was observed that the environmental impact was reduced by improving the materials of zinc-galvanized wire. The model basin investigated in this study was the $0.3km^2$ area of river improvement works in Kyung stream, which is a tributary to the Seomjin river and the second regional stream. The research was conducted based on the 30years by life expectancy of artificial facilities. For the comparisons of revetment techniques with respect to the environmental qualities, the method resulted in the highest environmental loadings. The method using ready-mixed concrete ranked second in the environmental loadings of revetment techniques. The present results of this study are expected to play a beneficial role in the nature-friendly design of close-to-nature river by quantitatively identifying the environmental quality of total procedures (i.e., combination of techniques, selection of river-facility materials, maintenance of river-facility) applied to close-to-nature river plan.

A Case Study on Instruction for Mathematically Gifted Children through The Application of Open-ended Problem Solving Tasks (개방형 과제를 활용한 수학 영재아 수업 사례 분석)

  • Park Hwa-Young;Kim Soo-Hwan
    • Communications of Mathematical Education
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    • v.20 no.1 s.25
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    • pp.117-145
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    • 2006
  • Mathematically gifted children have creative curiosity about novel tasks deriving from their natural mathematical talents, aptitudes, intellectual abilities and creativities. More effect in nurturing the creative thinking found in brilliant children, letting them approach problem solving in various ways and make strategic attempts is needed. Given this perspective, it is desirable to select open-ended and atypical problems as a task for educational program for gifted children. In this paper, various types of open-ended problems were framed and based on these, teaming activities were adapted into gifted children's class. Then in the problem solving process, the characteristic of bright children's mathematical thinking ability and examples of problem solving strategies were analyzed so that suggestions about classes for bright children utilizing open-ended tasks at elementary schools could be achieved. For this, an open-ended task made of 24 inquiries was structured, the teaching procedure was made of three steps properly transforming Renzulli's Enrichment Triad Model, and 24 periods of classes were progressed according to the teaching plan. One period of class for each subcategories of mathematical thinking ability; ability of intuitional insight, systematizing information, space formation/visualization, mathematical abstraction, mathematical reasoning, and reflective thinking were chosen and analyzed regarding teaching, teaming process and products. Problem solving examples that could be anticipated through teaching and teaming process and products analysis, and creative problem solving examples were suggested, and suggestions about teaching bright children using open-ended tasks were deduced based on the analysis of the characteristic of tasks, role of the teacher, impartiality and probability of approaching through reflecting the classes. Through the case study of a mathematics class for bright children making use of open-ended tasks proved to satisfy the curiosity of the students, and was proved to be effective for providing and forming a habit of various mathematical thinking experiences by establishing atypical mathematical problem solving strategies. This study is meaningful in that it provided mathematically gifted children's problem solving procedures about open-ended problems and it made an attempt at concrete and practical case study about classes fur gifted children while most of studies on education for gifted children in this country focus on the studies on basic theories or quantitative studies.

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A Study of Minimum Reinforcement Ratio of Singly Reinforced Beamy (단철근 보의 최소철근비에 대한 고찰)

  • Choi, Seung-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.396-402
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    • 2021
  • A cross section in RC flexural members must be designed to satisfy flexural strength and ductility requirements simultaneously. In design provisions, ductile behavior is ensured by a sufficient reinforcement ratio or depth of the neutral axis. If the reinforcement ratio is less than the balanced reinforcement ratio, ductile behavior is secured, and this value is theoretically the maximum reinforcement ratio. But for a cross section with less steel, brittle failure can occur regardless of ductile behavior because of unqualifying a cracking moment. Recently, designs with a minimum steel ratio have been increasing along with the use of high-strength material, so in design provisions, a minimum amount of reinforcement is suggested. In the KCI(2012) standard, a minimum amount of reinforcement was suggested in terms of strength of steel and concrete. But in the revised KCI(2017) standard, a minimum amount of reinforcement was suggested by a relationship between the design flexural strength and cracking moment indirectly. This code can reflect the effect of cover thickness, but a material model must be defined. Therefore, the minimum amount of reinforcement in KCI(2012) and KCI(2017) was examined, and a rational review method was studied by parametric analysis.

A New Model of Records Centers, Integration Archives : Reoranization of the Education office Records Centers (기록관의 새로운 모델, 통합기록관 교육청 기록관 체계의 재편성)

  • Lim, Hee-yeon
    • The Korean Journal of Archival Studies
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    • no.58
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    • pp.31-63
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    • 2018
  • The foremost priority for establishing record management of public institutions is strengthening the function and role of the records centers in the institutions and creating the foundation of the organization and personnel for demonstrating professionalism of archivists. However, concept of current records center is not clear and there is no substance of the organization. It also says that once a records manager is deployed, a records center is founded since appointment criteria for archivists is prone to be interpreted subjectively by the institutions. Therefore, it's time for more concrete improvements to resolve these issues. This research analyses some problems found in the system of records centers in the main office and district offices of education focusing on the environment of them. The problems are centers without substance in district offices of education because of the organization structure that all authority has been assembled in the main office, and the reality of records managers who have fallen into records discarders, etc. To solve these problems, this paper proposes changing the appointment criteria for archivists, operating an integrated records center reflecting the intensive working system, and legislating special act on record management of educational institutions.

Teaching and Learning of University Calculus with Python-based Coding Education (파이썬(Python) 기반의 코딩교육을 적용한 대학 미적분학의 교수·학습)

  • Park, Kyung-Eun;Lee, Sang-Gu;Ham, Yoonmee;Lee, Jae Hwa
    • Communications of Mathematical Education
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    • v.33 no.3
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    • pp.163-180
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    • 2019
  • This study introduces a development of calculus contents which makes to understand the main concepts of calculus in a short period of time and to enhance problem solving and computational thinking for complex problems encountered in the real world for college freshmen with diverse backgrounds. As a concrete measure, we developed 'Teaching and Learning' contents and Python-based code for Calculus I and II which was used in actual classroom. In other words, the entire process of teaching and learning, action plan, and evaluation method for calculus class with Python based coding are reported and shared. In anytime and anywhere, our students were able to freely practice and effectively exercise calculus problems. By using the given code, students could gain meaningful understanding of calculus contents and were able to expand their computational thinking skills. In addition, we share a way that it motivated student activities, and evaluated students fairly based on data which they generated, but still instructor's work load is less than before. Therefore, it can be a teaching and learning model for college mathematics which shows a possibility to cover calculus concepts and computational thinking at once in a innovative way for the 21st century.

A Study on Strategic Management of Native Advertisement (네이티브 광고의 전략적 관리방안에 관한 연구)

  • Son, Jeyoung;Kang, Inwon
    • Management & Information Systems Review
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    • v.38 no.1
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    • pp.63-81
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    • 2019
  • In order to overcome the disadvantages of banner ad, pop-up ad, interstitial ad, which are existing web advertisement forms, native ad is actively utilized. Native advertising is considered to be a useful advertising technique in that it can reduce users' rejection and attract attention. However, in recent years, there have been a lot of fake news and fake contents that have turned articles or video contents into advertisements. The purpose of this study is to understand how firms can coordinate and control native advertisements in a rational way. For this analysis, we conducted a survey of 308 social media users using quota sampling method. As a result of the verification, it was found that the more negative the perception of the evaluation of the advertisement, the less the level of persuasion about the advertisement and the negative impact on the website where the advertisement is exposed. In addition, this study examined the influence of the negative stimulus factors on the qualitative performance of the firm. As a result, it was found that source non-expert had the highest effect on skepticism on ad. Also, platform overflow has a direct effect on the evaluation of the website as well as the negative evaluation of the advertisement. Moreover, this study provides concrete implications for the subdivision market by verifying the differences between the paths according to the level of website involvement.

Life long learning system crate major impact on dominant organizations in the world (평생학습 시스템이 세계의 지배적인 조직에 미치는 주요 영향)

  • Chandrakant, Mehta Jaydip
    • Industry Promotion Research
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    • v.4 no.1
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    • pp.57-66
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    • 2019
  • The extant research literature is scant in telling us how organizations actually implement lifelong learning practices and policies. Hence, the purpose of this paper is to describe how lifelong learning is grounded in practice. We do this by introducing a new conceptual framework that was developed on the basis of interviews with a number of leading edge corporations from Canada, the USA, India and Korea. At the heart of our model, and any effective lifelong learning system, is a performance management system. The performance management system allows for an ongoing interaction between managers and employees whereby challenging performance and learning goals are set, and concrete plans are made to achieve them. Those plans involve three types of learning activities. First, employees may be encouraged to engage in formal learning. This could be provided in-house, or the employee may take a leave of absence and return to school. Second, managers may deploy their subordinates to different departments or teams, so that they can take part in new work-based learning opportunities. Finally, employees may be encouraged to learn on their own time. By this we mean learning after organizational hours through firm-sponsored 5 programs, such as e-learning courses. Fueled by the performance management system, we posit that these three learning outlets lead to effective lifelong learning in organizations.

Damage Analysis of Manganese Crossings for Turnout System of Sleeper Floating Tracks on Urban Transit (도시철도 침목플로팅궤도 분기기 망간크로싱의 손상해석)

  • Choi, Jung-Youl;Yoon, Young-Sun;Ahn, Dae-Hee;Han, Jae-Min;Chung, Jee-Seung
    • The Journal of the Convergence on Culture Technology
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    • v.8 no.5
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    • pp.515-524
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    • 2022
  • The turnout system of the sleeper floating tracks (STEDEF) on urban transit is a Anti-vibration track composed of a wooden sleeper embedded in a concrete bed and a sleeper resilience pad under the sleeper. Therefore, deterioration and changes in spring stiffness of the sleeper resilience pad could be cause changes in sleeper support conditions. The damage amount of manganese crossings that occurred during the current service period of about 21 years was investigated to be about 17% of the total amount of crossings, and it was analyzed that the damage amount increased after 15 years of use (accumulated passing tonnage of about 550 million tons). In this study, parameter analysis (wheel position, sleeper support condition, and dynamic wheel load) was performed using a three-dimensional numerical model that simulated real manganese crossing and wheel profile, to analyze the damage type and cause of manganese crossing that occurred in the actual field. As a result of this study, when the voided sleeper occurred in the sleeper around the nose, the stress generated in the crossing nose exceeded the yield strength according to the dynamic wheel load considering the design track impact factor. In addition, the analysis results were evaluated to be in good agreement with the location of damage that occurred in the actual field. Therefore, in order to minimize the damage of the manganese crossing, it is necessary to keep the sleeper support condition around the nose part constant. In addition, by considering the uniformity of the boundary conditions under the sleepers, it was analyzed that it would be advantageous to to replace the sleeper resilience pad together when replacing the damaged manganese crossing.

Settlement Evaluation of Caisson-Type Quay Wall Using PSI of Velocity During Earthquake (지진시 속도의 PSI를 활용한 케이슨식 안벽의 침하량 평가 )

  • Gichun Kang;Hyunjun Euo;Minje Baek;Hyunsu Yun;Jungwook Choi;Seong-Kyu Yun
    • Journal of the Korean Geosynthetics Society
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    • v.22 no.2
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    • pp.71-83
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    • 2023
  • It is very important to predict the amount of settlement in order to maintain the function of the coastal structure. Finite element analysis methods and real and model experiments are used as methods for this, but this has the disadvantage of requiring a lot of cost and time. Therefore, this study was conducted for the purpose of a simple formula proposal that can easily predict the amount of settlement of the caisson-type quay wall structure. In the research process, after calculating the PSI (Power Spectrum Intensity) of the velocity, the amount of settlement of the structure is calculated by substituting it into the simple formula of the existing gravity breakwater. By comparing and analyzing the amount of settlement of the structure obtained through numerical analysis, it was confirmed that the error between the amount of settlement of the existing simple formula and the amount of settlement of the numerical analysis was large, and it was confirmed that the background could not be considered in the case of the existing simple formula. Therefore, this study proposed a correction factor for the background of the quay wall structure, indicating a simple formula that can obtain the amount of settlement of the caisson-type quay wall structure. Compared to the numerical analysis settlement amount, it was judged that this simple formula had sufficient precision in calculating the caisson-type quay wall settlement amount. In addition, facilities vulnerable to earthquake resistance can be easily extracted in situations where time and cost are insufficient, and it is expected to be used as a screening technique.

A Study on the Direction of Cultural City Designation Project in the Case of European Capitals of Culture (유럽문화수도 사례로 본 문화도시 지정사업의 방향성 고찰)

  • Kim, Sun Young;Yi, Eui Shin
    • Korean Association of Arts Management
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    • no.52
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    • pp.135-156
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    • 2019
  • The purpose of this study is to derive more practical and concrete policy implications for the successful implementation of the Cultural City Designation Project, which is emerging as a main topic of cultural policy. To this end, the background and implementation system of the European Capitals of Culture(ECOC), which is the subject of benchmarking in various aspects, were examined. As a result, it was confirmed that there is a possibility that the Cultural City Designation Project can reveal its limitations in the background and process, and the improvement is as follows. First, rather than creating an ideal cultural city model to achieve its goals in a short period of time, efforts should be made to secure diversity and expand insufficient infrastructure in accordance with local autonomous decisions. Second, in order to secure the continuity of the business, it is necessary to secure and educate professional manpower for organizational operation in the form of independent or direct agency of each local government. Finally, careful policy consideration should be made at the national level to balance regional interests. Therefore, there is a need for an organized 'government-level organization' that can take on the role of the city selection process, support system, and ex post evaluation. In short, successful cultural city projects require critical acceptance and efforts to remedy fundamental problems rather than benchmarking unconditional overseas cases in terms of cultural policy.