• Title/Summary/Keyword: tool material

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Improving Lecture Quality using SOFM neural network and C4.5 (SOFM신경망과 C4.5를 활용한 강의품질 개선)

  • Lee, Jang-hee
    • Journal of Practical Engineering Education
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    • v.6 no.2
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    • pp.71-76
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    • 2014
  • Improving lecture quality is very necessary for the service quality of education in universities, enterprises and education institutes. The student lecture evaluation survey data is a good tool for measuring lecture quality and have been often analyzed by simple statistical methods. This study presents an intelligent lecture quality improvement method that can improve student's overall satisfaction and performance by analyzing student lecture evaluation survey data. The method uses SOFM (Self-Organizing Feature Map) neural network and C4.5 to find the patterns in student's satisfaction and performance more correctly and then decide what to change in the lecture for the improvement of student's satisfaction and performance. We apply the proposed method to an enterprise lecture in Korea. We can find that it can improve the quality of an enterprise lecture by changing total lecture time, lecture material and organization of lecture schedule to be necessary improvements.

A Development and Application of the Environmental Education Text Book about the Asian Dust in the Elementary School (초등학교에서 황사에 관한 환경교육 교재의 개발과 적용)

  • Chun, Jong-Suk;Moon, Yun-Seob;Hur, Yong-Won
    • Hwankyungkyoyuk
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    • v.21 no.2
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    • pp.51-67
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    • 2008
  • The purpose of this study is to develop and applicate the elementary environmental textbook in order to solve its problem and to improve attitude related to the Asian dust. The results in this research are as follows. First, it was showed that three groups who composed of teachers, parents and students in the elementary school had recognized the serosities and problems caused by the Asian dust form TV, and that such problems was associated with increase of the desertification and the global warming. Especially the student group insist that the cause in Asian dust is due to the natural phenomena or industrialization. Second, as a result in analysis on the Asian dust through both textbooks on the 7th elementary curriculum and subsidiary textbooks, contents concerning Asian dusts was little or noting. In addition, in the subjects of Science, Society and Health for the 5th and 6th grade students in the elementary school, they were explained partially as one of the air pollutants. Third, the elementary environmental textbook on the Asian dust was developed for the 5th and 6th grade students. The textbook is composed of four contents on the material which is harmful of the human health and life in Asian dust, the special news of Asian dust, and the best answer to solve Asian dust as well as the cause and the source of Asian dust. Forth, as a result in classes using the environmental textbook developed by four themes about the Asian dust, its application is meaningful in the level of p value in the view of knowledge, awareness and attitude of the experiment group. They was more improved in 37%, 14%, and 15%, respectively, than the comparative group. In conclusion, the environmental textbook related to Asian dust will play an important role in useful tool to understand the right knowledge, awareness, and attitude which makes an effort on its effective management in the elementary school.

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Springback Analysis of the Front Side Member with Advanced High Strength Steel (고강도 강판을 적용한 프런트 사이드 멤버의 스프링백 해석)

  • Song J. H.;Kim S. H.;Park S. H.;Huh H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2005.05a
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    • pp.106-109
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    • 2005
  • Springback is a common phenomenon in sheet metal forming, caused by the elastic recovery of the internal stresses after removal of the tooling. Recently, advanced high strength steels (AHSS) such as TRIP and DP are finding acceptance in the automotive industry because their superior strength to weight ratio can lead to improved fuel efficiency and assessed crashworthiness of vehicles. The major troubles of the automotive structural members stamped with high strength steel sheets are the tendency of the large amount of springback due to the high yield strength and the tensile strength. The amount of springback is mainly influenced by the type of the yield function and anisotropic model induced by rolling. The discrepancy of the deep drawn product comparing the data of from the product design induced by springback must be compensated at the tool design stage in order to guarantee its function and assembly with other parts. The methodology of compensation of the low shape accuracy induced by large amount of springback is developed by the expert engineer in the industry. Recently, the numerical analysis is introduced in order to predict the amount of springback and to improve the shape accuracy prior to tryout stage of press working. In this paper, the tendency of springback is evaluated with respect to the blank material. The stamping process is analyzed fur the front side member formed with AHSS sheets such as TRIP60 and DP60. The analysis procedure fully covers the binderwrap, stamping, trimming and springback process with the commercial elasto-plastic finite element code LS-DYNA3D.

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Creep Analysis of Type 316LN Stainless Steel Using Reference Stress (참조응력을 이용한 316LN 스테인리스강의 크리프 해석)

  • Kim, Woo-Gon;Ryu, Woo-Seog
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.10
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    • pp.2122-2129
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    • 2002
  • Creep damage using a reference stress(RS) was analyzed for type 316LN stainless steel. The generalized K-R equation was reconstructed into the RS equation using a critical stress value $\sigma$. The RS equation was derived from the critical stress in failure time $t_f$ instead of material damage parameter $\omega$, which indicates the critical condition of collapse or approach to gross instability of materials during creep. For obtaining the reference stress, a series of creep tests and tensile tests were conducted with at 55$0^{\circ}C$ and $600^{\circ}C$. The stress-time data obtained from creep tests were applied to the RS equations to characterize the creep damage of type 316LN stainless steel. The value of creep constant r with stress levels was about 18 at 55$0^{\circ}C$ and 21 at $600^{\circ}C$. This value was almost similar with r = 24 in the K-R equation, which was obtained by using damage parameter $\omega$. Relationship plots of creep failure strain and life fraction $(t_f /t_r)$ were also obtained with different λ values. The RS equation was therefore more convenient than the generalized K-R equation, because the measuring process to quantify the damage parameter $\omega$ such as voids or micro cracks in crept materials was omitted. The RS method can be easily used by designers and plant operator as a creep design tool.

Development of Feature-based Encapsulation Process using Filler Material (충진재를 이용한 특징형상 가공용 RFPE 공정 개발)

  • Choe, Du-Seon;Lee, Su-Hong;Sin, Bo-Seong;Yun, Gyeong-Gu;Hwang, Gyeong-Hyeon;Lee, Ho-Yeong
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.1
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    • pp.98-103
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    • 2001
  • Machining is the commonly used process in the manufacturing of prototypes. This process offers several advantages, such as rigidity of the machine, precision of the machine, precision of the operation and specially a quick delivery. The weight and immobility of the machine support and immobilize the part during the operation. However, despite these advantages it shows, machining still presents several limitations. The immobilization, location and support of the part are referred to as fixturing or workholding and present the biggest challenge for time efficient machining. So it is important to select and design the appropriate fixturing assembly. This assembly depends on the complexity of the part and the tool paths and may require the construction of dedicated fixtures. With traditional techniques, the range of fixturable shapes is limited and the identification of suitable fixtures in a given setup involves complex reasoning. To solve this limitation and to apply the automation, this paper presents the Reference Free Part Encapsulation(RFPE) and implementation of the encapsulation system. The feature-based modeling system and the encapsulation system are implemented. The small part of which it is difficult to find out the appropriate fixturing assembly is made by this system.

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PEMFC Optimization Design Using Genetic Algorithm (유전자 알고리즘을 이용한 고분자 전해질 연료전지 최적화 설계)

  • Yang, Woo-Joo;Wang, Hong-Yang;Lee, Dae-Hyung;Kim, Young-Bae
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.38 no.11
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    • pp.889-897
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    • 2014
  • This paper presents a method for finding an optimized result by using a genetic algorithm (GA) based on a PEMFC analysis result. The conventional analysis method designs fuel cells one-by-one, and each result is compared to obtain the best performance. Because the computational burden of the conventional analysis is enormous, the present optimization process provides an inefficient tool by automatically setting the boundary and material properties and mesh generation. As the change can be reflected automatically in the channel geometry with GA, the fuel cell analysis result with various sizes can be obtained easily. Therefore, the global maximum performance can be obtained through a GA optimization procedure.

A Study on Developing Facets for Subject Headings in Korea (한국 주제명 표목의 패싯 유형 개발에 관한 연구)

  • Choi, Yoon Kyung;Chung, Yeon-Kyoung
    • Journal of the Korean Society for Library and Information Science
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    • v.49 no.4
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    • pp.179-201
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    • 2015
  • The subject heading is an elaborate access tool for subject browsing and searching in information retrieval environment. The purpose of this study is to suggest the applicable facets to subject headings in Korea. First, the concepts of subject and the definitions of facets were investigated in the literature review. Second, six cases including OCLC's FAST, PRECIS, "Thesaurus construction and use", CC $7^{th}$ edition, BC $2^{nd}$ Edition, and UDC $3^{rd}$ Edition were analyzed to focus on configuration of facets as case studies. Based on the results, twenty-two facets were proposed including Topical, Event, Geography, Chronology, Personal and Corporate Name, Title, Form, Genre, Language, and Person facets as 11 top facets. Also, Topical-Thing/Entity and Topical-Action/Status, Part, Kind, Property, Whole, Material, Patient, Product, By-Product and Agent facets as sub-facets of Topical facet.

Proposal of VMD for a Footwear Shop at Department Stores - Focused on a Footwear Shop for Women at a "H" Department Store -

  • Lee, Mi-Young;Kim, Soon-Ku
    • Journal of Fashion Business
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    • v.6 no.3
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    • pp.28-40
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    • 2002
  • For modern man and woman, footwear is considered a fashion for expressing oneself, and not merely a protective tool for the feet. The purpose of this research is to increase the effect of sales promotional activities by emphasizing product image and by enhancing sales environment. Towards this end, this research focuses on the study of environment at footwear stores that meet the challenges incurred by the changing lifestyles of consumers and the ensuing dynamics of the society in general. Research is based on an in-depth, thorough study of the previous research works and entails examining theoretical background and the concept of Visual Merchandising Display (VMD). Research will focus on the analysis of current situation at footwear stores located in department store based on material research on footwear stores and theoretical examination. Research on the current situation of footwear stores at department store will be conducted from the VMD perspective. In the end, this research paper will make suggestions on the VMD measures for footwear stores with the aim of increasing sales by satisfying consumers' sensibility and purchasing desire. Suggestions will be made based on the results of the research. -Study of current VMD status per fixture centered on 18 brands at department store -Suggestions for VMD at footwear stores based on the survey results of customer purchasing behavior This research intends to develop structured VMD methodology for footwear stores based on the research centered on VMD research of footwear stores at department store. Significance of this research lies in its aim to contribute to the sales increase, no matter how trivial it might be. Going a step further, this research work could be considered one of the foundations for defining the role of VMD methodology at footwear stores. Suggested results are as follows. (1) Need to cast away from simple, one-dimensional type of display method at footwear stores and transform into product image oriented VMD (2) Need to highlight product image by fully leveraging props and by developing footwear display methods that are suitable for different types of fixtures (3) Need to stabilize VMD by developing footwear manual that enables efficient management by store operator.

Establishment of CO2 Emission Estimation BIM Library for Steel Structures (철골조 건물의 탄소배출량 산정을 위한 BIM 라이브러리 구축)

  • Lee, Jae-Cheol;Jung, Jong-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.5
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    • pp.3169-3175
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    • 2014
  • In this paper, we have established the procedures for $CO_2$ emission estimation BIM libraries by using the material takeoff function that BIM tools fundamentally provide, and verified its availability by applying to steel structures. The BIM library set-up procedures were made up of $CO_2$ emission coefficients and parameter extraction, project unit setting, parameter setting, and $CO_2$ emission quantity calculation formula set-up. We used Revit Architecture 2013 as BIM tool, and established the steel members' family libraries as BIM libraries. It is possible to calculate the $CO_2$ emission quantity by following the proposed BIM library set-up procedures, and users have only to input the $CO_2$ emission coefficients and unit weights of steel members being used. We expect that the results contribute to practical use of BIM in field, and vitalizations of the eco-friendly construction.

Construction of web-based nutrition education contents and searching engine for usage of healthy menu of children

  • Hong, Soon-Myung;Lee, Tae-Kyong;Chung, Hea-Jung;Park, Hye-Kyung;Lee, Eun-Ju;Nam, Hye-Seon;Jung, Soon-Im;Cho, Jee-Ye;Lee, Jin-Hee;Kim, Gon;Kim, Min-Chan
    • Nutrition Research and Practice
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    • v.2 no.2
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    • pp.114-120
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    • 2008
  • A diet habit, which is developed in childhood, lasts for a life time. In this sense, nutrition education and early exposure to healthy menus in childhood is important. Children these days have easy access to the internet. Thus, a web-based nutrition education program for children is an effective tool for nutrition education of children. This site provides the material of the nutrition education for children with characters which are personified nutrients. The 151 menus are stored in the site together with video script of the cooking process. The menus are classified by the criteria based on age, menu type and the ethnic origin of the menu. The site provides a search function. There are three kinds of search conditions which are key words, menu type and "between" expression of nutrients such as calorie and other nutrients. The site is developed with the operating system Windows 2003 Server, the web server ZEUS 5, development language JSP, and database management system Oracle 10 g.