• Title/Summary/Keyword: properties and analysis

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Effect of femoral mechanical properties on primary stability of cementless total hip arthroplasty: a finite element analysis

  • Reimeringer, Michael;Nuno, Natalia
    • Advances in biomechanics and applications
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    • v.1 no.3
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    • pp.187-210
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    • 2014
  • With the goal of increasing the survivorship of the prosthesis and anticipating primary stability problems of new prosthetic implants, finite element evaluation of the micromotion, at an early stage of the development, is mandatory. This allows assessing and optimizing different designs without manufacturing prostheses. This study aimed at investigating, using finite element analysis (FEA), the difference in the prediction of the primary stability of cementless hip prostheses implanted into a $Sawbones^{(R)}$ 4th generation, using the manufacturer's mechanical properties and using mechanical properties close to that of human bone provided by the literature (39 papers). FEA was carried out on the composite $Sawbones^{(R)}$ implanted with a straight taper femoral stem subjected to a loading condition simulating normal walking. Our results show that micromotion increases with a reduction of the bone material properties and decreases with the augmentation of the bone material properties at the stem-bone interface. Indeed, a decrease of the cancellous Young modulus from 155MPa to 50MPa increased the average micromotion from $29{\mu}m$ up to $41{\mu}m$ (+42%), whereas an increase of the cancellous Young modulus from 155MPa to 1000MPa decreased the average micromotion from $29{\mu}m$ to $5{\mu}m$ (-83%). A decrease of cortical Young modulus from 16.7GPa to 9GPa increase the average global micromotion from $29{\mu}m$ to $35{\mu}m$ (+33%), whereas an increase of the cortical Young modulus from 16.7GPa to 21GPa decreased the average global micromotion from $29{\mu}m$ to $27{\mu}m$ (-7%). It can also be seen that the material properties of the cancellous structure had a greater influence on the micromotion than the material properties of the cortical structure. The present study shows that micromotion predicted at the stem-bone interface with material properties of the $Sawbones^{(R)}$ 4th generation is close to that predicted with mechanical properties of human femur.

A Numerical Study on the Response of Jointed Rock Mass Due to Thermal Loading of Radioactive Waste (방사성 폐기물의 열하중에 의한 절리암반의 거동에 관한 수치해석적 연구)

  • 문현구;주광수
    • Tunnel and Underground Space
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    • v.4 no.2
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    • pp.102-118
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    • 1994
  • Thermomechanical analysis is conducted on the radioactive repository in deep rock mass considering the in-situ stress, excavation and thermal loading of a radioactive waste. Thermomechanical properties of a discontinuous rock mass are estimated by a theoretical method so called sequential analysis. Using the estimated properties as input for finite element analysis, the influence on temperature distribution and thermal stress is analyzed within the scope of 2-dimensional steady state and transient heat transfer and coupled thermal elastic plastic behaviour. Granitic rock mass is taken for this analysis. The analysis is done for two different rock mass conditions, i.e. continuous-homogeneous and highly jointed conditions, for the purpose of comparison. In the case of steady state, the extent of disturbed zone around the storage tunnel due to the heat production of the spent-fuel canister varies depending on the thermomechanical properties of the rock mass. In the case of transient analyses, the response of the jointed rock mass to the thermal loading after radioactive waste disposal varies significantly with time, resulting in dramatic changes in the both size and location of disturbed zone.

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Transient Response Analysis of Linear Dynamic System with Random Properties (확률론적 특성을 갖는 선형 동적계의 과도응답 해석)

  • 김인학;독고욱
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1996.10a
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    • pp.62-69
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    • 1996
  • Most dynamic systems have various random properties in excitation and system parameters. In this paper, a procedure fur response analysis is proposed for the linear dynamic system with random properties in both excitation and system parameters. The system parameter and response with random properties are modeled by perturbation technique, aand then response analysis is formulated by probabilistic and vibration theories. And probabilistic FEM is also used for the calculation of mean response which is difficult by the proposed response model. As an application example, the transient response is calculated for a sdof system with random mass and spring constant subjected to stationary white-noise excitation and the results are compared to those of numerical simulation.

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A Study on the Status of Designated Cultural Properties of Modern Educational Facilities and The Meaning of Modern Architectural History (근대교육시설의 문화재 지정현황과 건축사적 의미)

  • Kim, Seung-Bae
    • Journal of the Korean Institute of Educational Facilities
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    • v.20 no.6
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    • pp.31-40
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    • 2013
  • The purpose of this study is to understand the meaning of architectural history of designated cultural properties of modern educational facilities through the analysis of its status. This study considerate acceptance and evolution of modern educational facilities during the about seventy years from 1895 to 1965. Also, this study analyzes items that is distribution of construction and designation year, regional groups, and status of main structure material, status of conservation and utilization of facilities, its characteristics of architectural style. In this study, the result of analysis show that most analysis items of investment buildings are tend to biased and concentration to one direction. Accordingly, designated cultural properties of modern educational facilities are weakly express architectural representation and symbolism in the period of modern educational acceptance.

Assessment of Equivalent Elastic Modulus of Perforated Spherical Plates

  • JUMA, Collins;NAMGUNG, Ihn
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.15 no.1
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    • pp.8-17
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    • 2019
  • Perforated plates are used for the steam generator tube-sheet and the Reactor Vessel Closure Head in the Nuclear Power Plant. The ASME code, Section III Appendix A-8000, addresses the analysis of perforated plates, however, this analysis is only limited to the flat plate with a triangular perforation pattern. Based on the concept of the effective elastic constants, simulation of flat and spherical perforated plates and their equivalent solid plates were carried out using Finite Element Analysis (FEA). The isotropic material properties of the perforated plate were replaced with anisotropic material properties of the equivalent solid plate and subjected to the same loading conditions. The generated curves of effective elastic constants vs ligament efficiency for the flat perforated plate were in agreement with the design curve provided by ASME code. With this result, a plate with spherical curvature having perforations can be conveniently analyzed with equivalent elastic modulus and equivalent Poisson's ratio.

A Study on the Consumer Perception and Factor Analysis of Food Tourism (음식관광에 대한 소비자의 인식 및 요인분석)

  • Kim, Eun-Hae;Lee, Min-A
    • Korean Journal of Community Nutrition
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    • v.15 no.1
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    • pp.83-93
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    • 2010
  • The purpose of this study is to investigate consumer perception and importance of food tourism properties and performance of the properties in Sangju province of Gyeongsangbuk-do. The study has found that persons who have food tourism experiences (75 persons, 50.7%) had slightly more than not experience persons (72 persons, 48.6%). Additionally, most of the respondents were usually satisfied with the local foods. Also, it was found that food tourism had been taken 1-2 times per 6 months (48 persons, 64.0%) on average, and 135 persons (91.2%) had intention of experiencing food tourism. According to the result of Importance-Performance Analysis (IPA) on consumers' food tourism properties, high importance was on 'There are attractive landscapes.' ($4.52\;{\pm}\;0.56$), 'Accommodations with reasonable price.' ($4.18\;{\pm}\;0.80$), and 'The food of the area is famous.' ($4.15\;{\pm}\;0.73$); and the properties such as 'There are local specialty shops or markets selling local produce.' ($3.03\;{\pm}\;0.83$), 'The climate is temperate.' ($3.03\;{\pm}\;0.87$), and 'There are attractive landscapes.' ($3.02\;{\pm}\;0.98$) showed average performance. A factor analysis about consumers' importances to the food tourism properties shows that the factors were divided into four kinds and each of the factors were named as 'convenience-stable propensity', 'valued-oriented propensity', 'adventurous-aggressive propensity' and 'traditional-active propensity'. Variance ratios of each factor were 22.319%, 10.286%, 8.723% and 6.239%, respectively. According to the result of a reliability analysis, Cronbach's alpha value was 0.8621, implying that reliability of each item was very high. Therefore, it is considered that development of food tourism products and promotion strategies therefore should be designed based on the importance of food tourism properties hereafter.

Specification and Analysis of System Properties by using Petri nets (페트리 네트를 이용한 시스템 속성의 명세 및 분석)

  • Lee, Woo-Jin
    • The KIPS Transactions:PartD
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    • v.11D no.1
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    • pp.115-122
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    • 2004
  • Software system modeling has a goal for finding and solving system's problems by describing and analyzing system model in formal notations. Petri nets, as graphical formalism, have been used in describing and analyzing the software systems such as parallel systems, real-time system, and protocols. In the analysis of Petri nets, general system properties such as deadlock and liveness are analyzed by the reachability analysis. On the other side, specific properties such as functional requirements and constraints are checked by model-checking. However, since these analysis methods are based on enumeration of ail possible states, there nay be state explosion problem, which means that system states exponentially increase as the size of system is larger. In this paper, we propose a new method for mechanically checking system properties with avoiding state explosion problem. At first, system properties are described in property nets then the system model and the property net are composed and analyzed. In the compositional analysis, system parts irrelevant to the specific property are reduced to minimize the analysis domain of the system. And it is possible to mechanically check whether a specific property is satisfied or not.

Manufacturing and Material Analysis of Collagen/Chitosan Conjugated Fibers for Medical Application (의료용 소재 활용을 위한 콜라겐/키토산 복합섬유의 제조 및 특성 분석)

  • Gwak, Hyeon Jung;Ahn, Hyunchul;Lee, Won Jun;Yeo, Sang Young
    • Textile Coloration and Finishing
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    • v.33 no.3
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    • pp.131-140
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    • 2021
  • Collagen and chitosan are used in medical and cosmetic materials as natural polymers. In order to utilize the advantages of the materials, collagen/chitosan conjugated wet-spun fibers were prepared. The analysis of surface, optical, thermal and mechanical properties was carried out on the various composition of collagen and chitosan. As a result of images analysis, it was verified that the collagen/chitosan conjugated fibers were stably spun. In addition, the optical and thermal properties of fibers were observed to be changed by hydrogen bond. As a result, an optimized composition could be found at an appropriate content. Moreover, the optimized fibers have mechanical properties similar to chitosan fibers, while improving the structural and thermal stability by its hydrogen bond. In addition, the wet-spun collagen/chitosan conjugated fibers can be applied to medical and various fields through mechanical properties according to content control.

Comparison of the Explanation on Visual Texture of Cotton Textiles using Regression Analysis and ANFIS - on Warmness (회귀분석과 ANFIS를 활용한 면직물의 시각적 질감에 대한 해석 비교 - 온난감을 중심으로)

  • 주정아;유효선
    • Science of Emotion and Sensibility
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    • v.7 no.3
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    • pp.15-25
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    • 2004
  • The regression analysis and Adaptive -Network based Fuzzy-inference system (ANFIS) were applied to the explanation on human's visual texture of cotton fabrics with 7 mechanical properties. The ANFIS uses the structure with fuzzy membership function and neural network. The results obtained by the statistical analysis through the coefficient of correlation and regression analysis showed that subjective texture had a linear relationship with mechanical properties. But It had a relatively low coefficient of determination and was difficult that the statistical analysis explained other relationship with the exception of a lineality and interaction among mechanical properties. Comparing the statistical analysis, the ANFIS was an effective tool to explain human's non-linear perceptions and their interactions. But to apply ANFIS to human's perceptions more effectively, it is necessary to discriminate effective input variables through controlling the properties of samples.

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The Precision 3D Monitoring to Preserve the Cultural Properties (문화재 보존을 위한 정밀 3차원 모니터링)

  • Nym, Young-Bin;Lee, Kook-Moo;Bae, Sang-Ho
    • Journal of Korean Society for Geospatial Information Science
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    • v.7 no.1 s.13
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    • pp.65-74
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    • 1999
  • The construction of precise digital data and analysis system is very important to fundamental data to preserve and repair cultural properties. This study is about to acquire of digital data and to construct of analysis system for efficient maintenance of cultural properties. On the chinaware with white slip and greyish-green glaze acquiring 3D digital data and carrying the spatial analysis and monitoring were done through the softcopy photogrammetry method. So, we intend to offer the efficient method to preserve cultural properties.

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