• Title/Summary/Keyword: material factors

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Analysis of Stress Intensity Factors for an Interface Crack in Anisotropic Dissimilar Materials by Boundary Element Method (경계요소법에 의한 이방성 이종재 접합계면 균열의 응력확대계수 해석)

  • 조상봉;권재도;김태규
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.2
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    • pp.359-370
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    • 1993
  • Up to now, most studies are on interface crack problems in isotropic-isotropic dissimilar materials, but it seems to be not so much on anisotropic dissimlar materials. In this study, the stress intensity factors for an interface crack in anisotropic dissimilar materials are analysed using author's proposed extrapolation method by BEM and we have done a parametric study about material properties or shapes of crack affecting to the stress intensity factors. However, as there are not other's comparable numerical results on these anisotropic dissimilar materials to the best of author's knowledge, the reliability of the present results was proved by following two methods. The first is considering the asymptotic characteristic about stress intensity factors for an interface crack in anisotropic materials when the ansiotropic material approachs to the isotropic material. The second is considering the discontinuity of stress intensity factors between of a crack in an identical homogeneous anisotropic material and an interface crack in anisotropic dissimilar materials.

Analysis of characteristics of TRL(Transmission line) in LTCC (low temperature cofired ceramic) system (저온 소성 유전체 세라믹 시스템에서의 전송 선로 특성 해석)

  • Yoo, Joshua;Lee, W.S.;Kang, N.K.;Park, J.C.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05c
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    • pp.23-26
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    • 2002
  • In ceramic systems using LTCC, many components including embedded passives and TRL's are used for composition of 3-dimensional circuit. So the exact analysis on this components must be performed. As for the TRL's, material properties including electrical conductivity of metal, loss factor and effective dielectric constant of dielectric material and geometrical factors like roughness of surface, vias, dimension of TRL structure have a large effect on the characteristics of transmission lines. Such properties of materials have different values in each system with ideal ones presented in text book. In this research, the effective material properties in each system are examined and the effect of material properties and geometrical factors on the characteristics of TRL's are analyzed and quantified by simulation and measurement.

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Stress-based topology optimization under buckling constraint using functionally graded materials

  • Minh-Ngoc Nguyen;Dongkyu Lee;Soomi Shin
    • Steel and Composite Structures
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    • v.51 no.2
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    • pp.203-223
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    • 2024
  • This study shows functionally graded material structural topology optimization under buckling constraints. The SIMP (Solid Isotropic Material with Penalization) material model is used and a method of moving asymptotes is also employed to update topology design variables. In this study, the quadrilateral element is applied to compute buckling load factors. Instead of artificial density properties, functionally graded materials are newly assigned to distribute optimal topology materials depending on the buckling load factors in a given design domain. Buckling load factor formulations are derived and confirmed by the resistance of functionally graded material properties. However, buckling constraints for functionally graded material topology optimization have not been dealt with in single material. Therefore, this study aims to find the minimum compliance topology optimization and the buckling load factor in designing the structures under buckling constraints and generate the functionally graded material distribution with asymmetric stiffness properties that minimize the compliance. Numerical examples verify the superiority and reliability of the present method.

Mediating Effects According to Family Type in the Complex Relationship between Psychological and Material Factors and Depression in the Elderly (노인의 심리적, 물질적 요인과 우울감, 복합관계에서 가족형태에 따른 조절효과분석)

  • Yang, Kyung-Hee;Jeong, Mun-Gyung
    • Journal of Digital Convergence
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    • v.13 no.7
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    • pp.437-444
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    • 2015
  • The aim of this study is to investigate influential factors for depression with respect to mental health in the elderly and present the groups in order to develop intervention strategies with human for the prevention of depression and suicide. For this purpose, this study held interviews using a questionnaire targeting normal elderly above the age of 65 who did not use social welfare services living in Seoul, Gyonggi and Jeonnam. The data collected was analysed with the use of a frequency test, a descriptive statistical analysis, a correlation analysis and a multi-regression analysis. The results of the study show that the influence of psychological factors in the subjects on their depression was significant. That is, Depending on your type of psychological factors of family influences the sense of difference of melancholy. Second, the influence of material factors of the subjects on their depression was significant depending on their family type. That is, the influence of material factors in the elderly on their depression differed depending on family type.

A study on the Preference of Material quality and the Demand Performance of Clothing for Underwear Materials (내의 소재에 대한 재질선호 및 요구 성능에 대한 연구)

  • Park, Young-Hee
    • Fashion & Textile Research Journal
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    • v.11 no.1
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    • pp.147-155
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    • 2009
  • This study has been made to examine the basic information, the preferences of material quality, and the demand performance of clothing for underwear materials between atopic patients and non-patients. The measurement tool was a questionnaire. For statistical analysis of data, crosstabs, ${\chi}^2$-test, t-test and ANOVA through SPSS for Windows(version 14.0) were used. The results obtained are as follows. The degree of the basic knowledge about clothing materials indicated that women was higher than men. The material decision method and the most considering part in case of selecting underwear products showed difference between men and women. The preference factors for underwear material quality were drawn with the five factors of sense of weight/pliability, lustering/see-through, tactility, and sense of cold and warmth. The preferred underwear material showed difference according to gender, existence and nonexistence of atopic determatitis, and degree of strength of skin itching caused by clothing materials. The demand performances of clothing in case of selecting underwear were drawn with the four factors of hygiene/practicality, skin protection, quality of materials, and aesthetic attribute. The demand performance of underwear showed difference according to gender, existence and nonexistence of atopic determatitis, degree of strength of skin itching caused by clothing materials.

The Selection of a Material Handling Systems using Multi-Attribute Decision Making (물류관리 시스템 선정을 위한 다기준 의사결정)

  • 정상윤;하승철;황문영
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.18 no.33
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    • pp.45-53
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    • 1995
  • The Purpose of this paper is to describe and demonstrate a quantitative procedure for evaluating alternative material handling systems that are being considered for possible purchase. The procedure considers both quantitative factors(i.e. costs) and qualitative factors(i.e. equipment productivity) that should be considered in the evaluation process. Since these factors are not always quantifiable it is necessary that the procedure be able to quantify all factors in commensurable units. This is accomplished via a modification of the Brown and Gibson model for facility site location and selection. The model was demonstrated via a case example that encompassed the derivation of performance measures for three material handling systems.

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A study on the factors affecting to material inflow in the drawing process (드로잉 공정에서 소재 유입에 영향을 미치는 인자에 관한 연구)

  • Lee, Sung-Min;Shin, Jin-Hee;Kim, Kyung-A;Lee, Chun-Kyn
    • Design & Manufacturing
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    • v.16 no.2
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    • pp.39-45
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    • 2022
  • Sheet Metal Forming by Press Forming Process takes a lot of time and cost from mold design to manufacturing. Therefore, all of die-makers are continuously conducting research to reduce the number of mold processes or the size of blanks to reduce costs. In the case of Forming complex shapes such as automobile component, wrinkles and cracks occur, so draw beads are used. Draw beads play an important role in suppressing the inflow of materials and minimizing the size of blanks. Factors that affect material flow include draw bead, blank holding pressure, lubricant, and surface roughness of punch and die. Most of the factors affect friction. In this study, after classifying circular beads and rectangular beads in cylindrical drawing molds using the AutoForm analysis program, the factors affecting the material inflow were considered.

Analysis of stripline structure(resonator) in LTCC system (LTCC system 에서의 Stripline구조 특성 연구)

  • 유찬세;이우성;강남기;박종철
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2002.05a
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    • pp.69-73
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    • 2002
  • In ceramic systems, many components including embedded passives and TRL(transmission line) are used for composition of 3-dimensional circuit. So the exact analysis on this components, As for the TRL's, material properties including electrical conductivity of metal, loss factor and effective dielectric constant of dielectric material and geometrical factors like roughness of surface, vias, dimension of stripline structure have a large effect on the charactersistics of transmission lines. In this research, of effect of material and geometrical factors on the characteristics of stripline structure is analyzed and quantified by simulation and measurement.

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A Study on the Clothing Attitudes and Purchasing Motives According to Consumption Orientation of Chinese Middle Aged Women (중국 중년 여성들의 소비성향에 따른 의복태도와 구매동기)

  • Kim, Yong-Sook;Liu, Guo-Lian;Wang, Hai-Yan
    • Journal of the Korean Society of Costume
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    • v.56 no.2 s.101
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    • pp.45-55
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    • 2006
  • The purposes of this study were to identify clothing attitudes and purchasing motives according to consumption orientation of Chinese middle aged women. The results of this study were as follows: 1. Factors of shopping orientation were rich & fashion, economy & profit, traditional virtue & leisure utilizing, and frugality & pragmatism. Chinese middle aged women were classified into practicality pursuit group, material & fashion pursuit group, conservative leisure utilizing group, and negative stagnating group. 2. Factors of clothing attitudes were fashion, self-confidence & symbol, politeness, comfort, and luxury. Practicality pursuit group considered politeness of clothing more and did not purchase impulsively, but material & fashion pursuit considered many factors of clothing attitudes most. Conservative leisure utilizing group considered economy most, but negative stagnate group considered less. 3. Factors of clothing purchasing motives were fashion & conformity, fitness, impulse, and practical needs. Practicality pursuit group purchased clothing because of practical needs, but material & fashion pursuit group purchased of fashion & conformity, fitness, impulse, and practical needs.

Optimization of Several Environmental Factors to Human Performance by Using Taguchi Method

  • Ismail, A.R.;Haniff, M.H.M.;Yusof, M.Y.M.;Rahman, M.N.A.;Ghani, J.A.
    • Industrial Engineering and Management Systems
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    • v.9 no.2
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    • pp.157-164
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    • 2010
  • The objective of this study is to determine the dominance effects of environmental factors such as Illuminance, humidity and Wet Bulb Globe Temperature (WBGT) on the operators' productivity at Malaysian electronic industry. A case study was carried out at an electronic components assembly factory. The environmental factors examined were the Illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, the humidity and WBGT level were measured by using Quest Temp apparatus and humidity. Taguchi Method was utilized to find the sequence of dominant factors that contributed to the productivity of operator at that specified production workstation. The study reveals that the dominant factor contributed to the productivity was WBGT, followed by illuminance and humidity.