• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.326-342
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• 2022

Comparative analyses of a shield building subjected to a large commercial aircraft impact between decoupling method and coupling method are performed in this paper. The decoupling method is applying impact force time-history curves on impact area of the shield building to study impact damage effects on structure. The coupling method is using a model including aircraft and shield building to perform simulation of the entire impact process. Impact force time-history curves of the fuselage, wing and engine and their total impact force time-history curve are obtained by the entire aircraft normally impacting the rigid wall. Taking aircraft structure and impact progress into account some loading areas are determined to perform some comparative analyses between decoupling method and coupling method, the calculation results including displacement, plastic strain of concrete and stress of steel plate in impact area are given. If the loading area is determined unreasonably, it will be difficult to assess impact damage of impact area even though the accurate impact force of each part of aircraft obtained already. The coupling method presented at last in this paper can more reasonably evaluate the dynamic response of the shield building than the decoupling methods used in the current nuclear engineering design.

• Journal of Korea Entertainment Industry Association
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• v.15 no.5
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• pp.163-173
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• 2021

This study tried to develop and implement a class model that can apply the teaching method that can operate learner-centered classes in university education to the class operation of the entire university, not individuals. For the development of the instructional model, the final model was derived through analysis of prior research, expert review, derivation of instructional model and design principles, pilot operation, primary questionnaire analysis, model and design strategy revision, and secondary questionnaire analysis. Shift_N⁺¹ class consists of 6 models, and each model was divided into 3 parts. It was a preliminary learning using video, a face-to-face class for question-and-answer and in-depth learning on the core content, and feedback and process evaluation for individual student. We have built our own computer system so that we can implement this every week. The teaching method model that can apply the learner-centered curriculum to all classes at the university was standardized. The Shift_N⁺¹ teaching method seeks to maximize the learner-centered learning effect by reflecting the characteristics of the subject, and to improve the quality of education by identifying students' achievements by week.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.2
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• pp.14-21
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• 2019

In recent years, the use of composite structures has become commonplace in various fields such as aerospace, architecture, and civil engineering. In this study, A method is proposed to find optimal position of bolt hole for fastening of composite structure. In the case of composites, stress distribution is very complicated, and design optimization based on this phenomenon increases difficulty. In selecting the optimum position of the bolt hole, the response surface method(rsm), which is a method of optimization, was applied. A response surface was created based on design points by multiple finite element analyzes. The position of the bolt hole that minimizes the stress when bolting on the response surface was found. The distribution of the stress at the position of the optimal hole was much lower than that of the initial design. Based on the results of this study, it is possible to increase the design safety factor of the structure by appropriately selecting the position of the bolt hole according to various load types when designing the structure and civil structure.

• The Mathematical Education
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• v.49 no.1
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• pp.67-83
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• 2010

The purpose of this study was to analyze the research trends of elementary mathematics education with regard to the topics, methods, subjects, and mathematical contents of such research. For this purpose, the papers published in domestic journals during the recent 5 years (2004-2009) were analyzed. A total of 383 papers from 8 professional journals were analyzed with the 4 criteria. First, the frequent research topics included instructional design and methods, learners' perspectives and abilities, and analysis of curriculum and textbooks in order. Second, qualitative research methodology was used twice as many as quantitative one. Whereas a survey was the most frequent quantitative research method, content analysis and case study were for qualitative methods. Third, research subjects included mainly typical students, specifically fifth and sixth graders. Papers dealing with lower graders or low-achievers as well as pre-service teachers were rare. Lastly, whereas the research on geometry as well as number and operations was active, that of measurement as well as probability and statistics was not. On the basis of these results, this paper includes several implications for the future research direction in elementary mathematics education.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.2
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• pp.439-449
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• 2016

The purpose of this study was to identify the effects of simulation-based education regarding care in a cardio-pulmonary emergency care as related to knowledge, critical thinking, and problem solving ability in nursing students. The study was conducted with a nonequivalent control group pre-posttest design. Seventy four participants were assigned to either the experimental group(34) or control group(40). The simulation-based cardio-pulmonary emergency care education included lecture, team-based practice, and debriefing, and it was implemented with the experimental group for a week from September 1 to December 11, 2015. Data were analyzed using chi-square, t-test and ANCOVA by using SPSS 21.0 program. The experimental group who had the simulation-based education showed significantly higher knowledge(F=24.930, p<.001), and critical thinking(F=5.951, p<.05) for cardio-pulmonary emergency care compared with the control group who had traditional education. However, there were no significant differences in problem solving ability(F=3.327, p>.072). The results indicate that a simulation-based education is an effective teaching method to improve knowledge and critical thinking in nursing students learning cardio-pulmonary emergency care. Further study is needed to identify the effect of a simulation-based team positive education program of nursing students.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.8
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• pp.164-173
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• 2001

The configuration of injection molded part can be classified into primary feature and supplementary feature. Even though supplementary features such as ribs, snap fits and bosses make mold more complicated, which cause the increasement of the mold cost, supplementary features should be attached to primary features because of assembly, reinforcement, moldability and other functional purposes. But it is not easy for novice designers to design them appropriately because of the profound knowledge related to Injection molding. In this paper, the intelligent design tool called ISFD(Intelligent Supplementary Feature Designer) which supplies easy, simple, time and cost-effective design method has been studied and developed. A knowledge-based design system is a new tool which enables the concurrent design and CIM with integrated and balanced design decisions at the initial design stage of injection molding.

• Journal of the Ergonomics Society of Korea
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• v.31 no.3
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• pp.469-474
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• 2012

The aim of this study is to develop an ergonomic design of magic saw handle considering user experiences. Background: Frequent use of hand tool can cause musculoskeletal disorders by inadequate wrist posture, excessive strength, repetitiveness, friction and pressure, vibration, etc. A hand tool that is inappropriately designed has higher risk causing musculoskeletal disorders. Complaints for the design of magic saw handle has been raised by many users according to the increasing use of magic saw. Method: Hand tool has to be designed considering worker's characteristics and task condition to prevent worker's musculoskeletal disorders. For this, user experiences for magic saw handle were measured through questionnaire survey and observation. Results: An ergonomic design of magic saw handle considering user experiences was proposed and then its design suitability was evaluated in comparison with the existing handle design using EMG and subjective evaluation. Conclusion: The proposed handle design showed higher satisfaction and lower muscular fatigue. Application: The results of this study can be effectively used to develop a new magic saw.

• Journal of Korean Society of Rural Planning
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• v.21 no.4
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• pp.167-175
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• 2015

The aim of this study is to establish resident-participative primary design of integrated rural development project with master planner by setting principals of open competition and transparent decision-making about village-to-village or business-to-business unit enterprise in Onui area, Hong-seong Gun. For effective processing, software projects such as residents education and rural landscape planning are simultaneously conducted for enhancing project understanding and comprehensive development plan including related post project. Above all, competition teams for individual project were organized to establish the resident-participative primary design using survey tables of residents demand. In 6 months resident-participative processing of primary design, continuous education and visiting to advanced area are conducted in team unit. Strengthened ability of team unit can be used in management and maintenance after project development. To do this, residents with the same opinions gathered as one competition team and identified business plans such as village asset, business location, size, program, and method for land securing. Favorable decision-making process by residents who are audience in project presentation of competition team has conducted. After selecting competition teams, continuos consulting are operated for establishing operation and management for developed or remodeled facilities through repetitive education and visiting advanced area. In this process, unit project suggested by competition team are completed. Preliminary selection was conducted by experts who were entrusted by residents. After residents agreement of project main stream such as major facilities and location, final detailed cost of projects are work out. Suggested process in this study which choose the final project by residents would improve residents' voluntary participation in integrated rural development project through open competition in establishing primary design.

• Journal of Fisheries and Marine Sciences Education
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• v.22 no.4
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• pp.553-565
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• 2010

The paper aims to evaluate the quality of fisheries census statistic and to provide some desirable directions and improvements for the future fisheries census, conducted by the Government. For the quality diagnosis of fisheries census statistic, specific processes of fisheries census and statistical qualities of each dimension are surveyed and evaluated by a Government's practician, two external examiners and a research group. Results show that census design, data analysis and quality control are evaluated relatively low in specific processes, and accessibility and comparability are evaluated relatively lower than relevance, accuracy, timeliness and consistency in statistical qualities. For minimizing the sampling errors, the probability proportion method should be employed in sampling methods from currently simple sampling method. In addition, fisheries census statistic is desirable to include and compare with those of different countries for consumer oriented data system.

• The Journal of Korean Institute for Practical Engineering Education
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• v.3 no.1
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• pp.92-96
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• 2011

If blueprint of analysis objects is not exist or this blueprint complexes, previous prediction techniques for product design have a problem that do not identify the exact physical characteristics. Even if target for analysing exists, transforming into a format that is supported by the program is a troublesome. To solve these problems, this thesis explains method for easily inputting design drawing and reducing the time of product design. In determining the physical characteristics of the target, method using color information is applied with electromagnetic analysis software to enable the analysis without relation to input type. Methods using color information to identify physical characteristic include some procedures. The first step is to number each of the colors, these colors number information includes material eigenvalues corresponding to the color. Next step analysis electromagnetic phenomena according with color information.