• Title/Summary/Keyword: multiple materials

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Constitutive Model of Tendon Responses to Multiple Cyclic Demands (II) -Theory and Comparison-

  • Chun, Keyoung-Jin;Robert P. Hubbard
    • Journal of Mechanical Science and Technology
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    • v.15 no.9
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    • pp.1281-1291
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    • 2001
  • The hereditary integral form of a quasi-linear viscoelastic law has been employed. Four new concepts have been employed: 1. a reduced relaxation function with a non-linear exponential function of time, 2. an inverse method to determine the scale factor of the elastic response, 3. an instant elastic recovery strain during unloading, and 4. the results of a constitutive model for cyclic tests may be a function of the Heavyside class. These concepts have been supported by agreement between measured and predicted responses of soft connective tissue to three types of multiple cyclic tests which include rest periods of no extension and alternations between different strain levels. Such agreement has not been attained in the previous studies. Chun and Hubbard (2001) is our companion experimental analysis paper.

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Intralobar Pulmonary Sequestration: A Case Report (Intralobar Pulmonary Sequestration: 수술 1예 보고)

  • 양기민;안긍환;김용일
    • Journal of Chest Surgery
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    • v.4 no.1
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    • pp.55-58
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    • 1971
  • Intralobar pulmonary sequestration is rare congenital lung disease, in which systemic artery supplies a congenitally cystic portion of the lung. Patient was 19 years old male whose complaints were fever, chest pain and sputum. Chest film showed a round homogenous density and air-fluid level at the left lower lung field and on bronchogram, contrast materials did not enter the abscess pocket. By operation multiple lung abscess pockets at the lower lobe were noted. An aberrant artery, measuring 0.4cm. in diameter and 2 cm. in length, arised from the aorta just above the diaphragm and entered the pusterior basal segment of left lower lobe. After division of the artery, left lower lobectomy was done ana postoperative hospital course was uneventful. Pathologic findings were multiple lung cysts which were not connected to the left lower lobe bronchi and an aberrant artery which showed elastic lamillation and mild sclerotic change.

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An Analysis of the Needs of the Preservice Secondary School Teacher on Understanding of International Society and Curriculum of International Understanding (국제사회의 이해 및 국제이해교육과정에 관한 중등 예비교사들의 인식 연구)

  • Park, So-Young;Park, Jae-Kook
    • Journal of Fisheries and Marine Sciences Education
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    • v.22 no.1
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    • pp.11-24
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    • 2010
  • The purpose of this study was to analyze the needs of the preservice secondary school teacher on understanding of international society and curriculum of international understanding and to derive the implications on developing curriculum of international understanding. This study used a questionnaire survey. The results are summarized as follows. First, it seems to be necessary to develop curriculum for satisfying the higesconcerns on worldsculture of preservice secondary school teacher. Second, the curriculum of educating international understanding for preservice secondary school teacher should contain such contents as multiple cultures, multiple perspectives, global relations and instructional materials. Third, it is necessary that instructions on educating international understanding should employ experience of global culture, discussion, lecture and so on.

Multiple Scale Processes in Microstructural Evolution: Case Study of Self-Reinforced β-Si3N4

  • Becher, Paul F.
    • Journal of the Korean Ceramic Society
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    • v.53 no.6
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    • pp.575-580
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    • 2016
  • Microstructural design of ceramics has generally focused on information gathered at the micro- and macro-scales and related this to how specific properties could be improved. Ceramic processing serves as the key to optimizes the final microstructure. However, the advent of nano-scale microstructures and highly advanced characterization tools are forcing us to develop new knowledge of what is occurring not just at the micro-scale but also at the atomic level. Thus we are now beginning to be able to address how microstructure is influenced by events at the atomic scale using atomic scale images and data. Theoreticians have joined us in interpreting the mechanisms involved in the "microstructural" evolution at multiple scales and how this can be used to enhance specific properties of ceramics. The focus here is on delving into the various layers the "microstructure" in order understand how atomic-scale events influence the structure and properties of ceramics.

A Study on the Development of Two side carrier Type Progressive Die toy Multi-Stage Drawing Process

  • Sim, Sung-Bo;Jang, Chan-Ho;Lee, Sung-Taeg
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.341-346
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    • 2002
  • The production part requiring multiple processes such as piecing, blanking and notching are performed with a high production rates in progressive die. In order to prevent the defects of process result, the optimum of strip process layout design, die design, die making, and tryout with inspection etc. are needed. According to these factors of die development process, they required theory and practice of metal working process and its background, die structure, machining conditions for die making, die materials, heat treatment of die components, know-how and so on. In this study, we designed and analyzed die components also simulated the strip process layout of multiple stage drawing by DEFORM. Especially the result of tryout and its analysis become to the feature of this study.

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A Relationship between Communication Situation and Adolescents' Aggression (커뮤니케이션 상황과 청소년의 공격성 간의 관계 분석(I))

  • 김정옥
    • Journal of the Korean Home Economics Association
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    • v.34 no.3
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    • pp.89-105
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    • 1996
  • The purpose of the study was to investigate the causal relationships between communication situation - communication apprehension(CA), family communication orientation(FCO), individual viewing motives and perceived realism of aggressive films - and aggression. The data from 193 high school students were analysed by SAS program. The respondents were asked to complete the self-report questionnaires, and the data were analysed by Cronbach's to the reliability, factor analysis, frequencies, percentage, means, standard deviation, Pearson's correlation coefficient, Duncan's multiple test, multiple regression, and path analysis, The results showed that CA was positively related to both aggression against the materials, and potential aggression. FCO had no direct effect on aggression but concept-oriented family affected indirect effect on aggression through viewing motives. The ritualistic motives were more positively related to aggression and identity than instrumental motive.

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Implementation of Fire Risk Estimation System for various Fire Situations using Multiple Sensors (다중 센서들을 이용한 다양한 화재 상황의 위험도 추정 시스템 개발)

  • Lee, Kwangjae;Lee, Youn-Sung
    • Journal of Sensor Science and Technology
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    • v.25 no.6
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    • pp.394-398
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    • 2016
  • In this paper, a fire detection system based on quantitative risk estimation is presented. Multiple sensors are used to build a comprehensive indicator that represents the risk of fire quantitatively. The proposed fire risk estimation method consists of two stages which determines the occurrence of fire and estimates the toxicity of the surveillance area. In the first stage, fire is reliably detected under diverse fire scenarios. The risk of fire is estimated in the second stage. Applying Purser's Fractional Effective Dose (FED) model which quantitates harmfulness of toxic gases, the risk of the surveillance area and evacuation time are calculated. A fire experiment conducted using four different types of combustion materials for the verification of the system resulted in a maximum error rate of 12.5%. By using FED calculation and risk estimation methods, the proposed system can detect various signs of fire faster than conventional systems.

Determination of a Multiattribute Utility Function Based on the Pairwise Comparison and the Application to Injection Molding Design (쌍대비교에 기초한 다속성 효용함수의 결정 및 사출성형설계에 대한 응용)

  • 박종천;김경모
    • Transactions of Materials Processing
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    • v.12 no.5
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    • pp.465-472
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    • 2003
  • Engineering design can be viewed as a decision making process, which involves the nonlinear tradeoffs task among the multiple conflicting attributes and considers the robustness of design. In order to obtain best engineering design, methodology for accurate assessment of his/her preference about the multiple attributes is required. Conventionally, intuitive procedures based on lottery questions are used to elicit the designer's preference structure: however, they can lead to inconsistent and inexact preference results due to the rank reversal problems derived from the designer's big cognitive burden. In this paper, alternatively, a design methodology based on multiattribute utility function through the pairwise comparison among alternatives is presented. The proposed procedure is applied to an actual injection mold design with the aid of the CAE simulation and the result is discussed.

Diffractive Alignment of Dual Display Panels

  • Shin-Woong Park;Junghwan Park;Hwi Kim
    • Current Optics and Photonics
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    • v.8 no.1
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    • pp.72-79
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    • 2024
  • Recent flat-panel displays have become increasingly complicated to facilitate multiple display functions. In particular, the form of multilayered architectures for next-generation displays makes precise three-dimensional alignment of multiple panels a challenge. In this paper, a diffractive optical alignment marker is proposed to address the problem of three-dimensional alignment of distant dual panels beyond the depth-of-focus of a vision camera. The diffractive marker is effective to analyze the positional correlation of distant dual panels. The possibility of diffractive alignment in multilayer display fabrication is testified with numerical simulation and a proof-of-concept experiment.

Measurement of Local Elastic Properties of Flip-chip Bump Materials using Contact Resonance Force Microscopy (접촉 공진 힘 현미경 기술을 이용한 플립 칩 범프 재료의 국부 탄성계수 측정)

  • Kim, Dae-Hyun;Ahn, Hyo-Sok;Hahn, Junhee
    • Tribology and Lubricants
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    • v.28 no.4
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    • pp.173-177
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    • 2012
  • We used contact resonance force microscopy (CRFM) technique to determine the quantitative elastic properties of multiple materials integrated on the sub micrometer scale. The CRFM approach measures the frequencies of an AFM cantilever's first two flexural resonances while in contact with a material. The plain strain modulus of an unknown or test material can be obtained by comparing the resonant spectrum of the test material to that of a reference material. In this study we examined the following bumping materials for flip chip by using copper electrode as a reference material: NiP, Solder (Sn-Au-Cu alloy) and under filled epoxy. Data were analyzed by conventional beam dynamics and contact dynamics. The results showed a good agreement (~15% difference) with corresponding values determined by nanoindentaion. These results provide insight into the use of CRFM methods to attain reliable and accurate measurements of elastic properties of materials on the nanoscale.