• Title/Summary/Keyword: Structural feature

검색결과 613건 처리시간 0.028초

안정적 좌굴 모델을 통한 저감쇠 직물 시뮬레이션

  • Choe, Gwang-Jin;Go, Hyeong-Seok
    • Journal of the Korea Computer Graphics Society
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    • 제8권1호
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    • pp.37-45
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    • 2002
  • We present a cloth simulation technique that is very stable yet also responsive. The stability of the technique allows the use of a large fixed time step when simulating various types of fabrics and character motions. The animations generated using this technique are strikingly realistic. Wrinkles form and disappear in a quite natural way, which is the feature that most distinguishes textile fabrics from other sheet materials. Significant improvements in both the stability and realism were made possible by overcoming the post-buckling instability as well as the numerical instability. The instability caused by buckling arises from a structural instability and therefore cannot be avoided by simply employing an implicit method. Addition of a damping force may help to avoid instabilities; however, it can significantly degrade the realism of the cloth motion. In this paper, a new buckling model based on immediate buckling assumption is proposed. A cloth element is assumed to reach a stable configuration immediately once it begins to buckle. This assumption makes it possible to simulate the fabric buckling stably without introducing any fictitious damping force. Consequently, it produces highly responsive cloth motion as well as improves the stability by modeling the fabric-specific buckling property adequately.

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Multi-FNN Identification Based on HCM Clustering and Evolutionary Fuzzy Granulation

  • Park, Ho-Sung;Oh, Sung-Kwun
    • International Journal of Control, Automation, and Systems
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    • 제1권2호
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    • pp.194-202
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    • 2003
  • In this paper, we introduce a category of Multi-FNN (Fuzzy-Neural Networks) models, analyze the underlying architectures and propose a comprehensive identification framework. The proposed Multi-FNNs dwell on a concept of fuzzy rule-based FNNs based on HCM clustering and evolutionary fuzzy granulation, and exploit linear inference being treated as a generic inference mechanism. By this nature, this FNN model is geared toward capturing relationships between information granules known as fuzzy sets. The form of the information granules themselves (in particular their distribution and a type of membership function) becomes an important design feature of the FNN model contributing to its structural as well as parametric optimization. The identification environment uses clustering techniques (Hard C - Means, HCM) and exploits genetic optimization as a vehicle of global optimization. The global optimization is augmented by more refined gradient-based learning mechanisms such as standard back-propagation. The HCM algorithm, whose role is to carry out preprocessing of the process data for system modeling, is utilized to determine the structure of Multi-FNNs. The detailed parameters of the Multi-FNN (such as apexes of membership functions, learning rates and momentum coefficients) are adjusted using genetic algorithms. An aggregate performance index with a weighting factor is proposed in order to achieve a sound balance between approximation and generalization (predictive) abilities of the model. To evaluate the performance of the proposed model, two numeric data sets are experimented with. One is the numerical data coming from a description of a certain nonlinear function and the other is NOx emission process data from a gas turbine power plant.

Behavior Analysis by Verticality Error of Monopile Foundation for 5MW Offshore Wind Turbine (5MW급 해상풍력발전기 모노파일 기초의 수직도 오차에 따른 거동 분석)

  • Jang, Hwa Sup;Kim, Ho Sun;Eum, Hark Jin;Kim, Mann Eung
    • KSCE Journal of Civil and Environmental Engineering Research
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    • 제32권2C호
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    • pp.61-68
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    • 2012
  • In general, verticality error necessarily occurs in marine pile foundation due to construction error or marine environmental effects. In marine structure, design by vertical load rather than horizontal load is dominant, but in the offshore wind turbine foundation, horizontal load is dominant. As the structure type that has dynamic movement by blade rotation, verticality error may have structurally significant effects. In this study, structural response feature of foundation and ground were analyzed according to verticality error of monopile foundation of 5MW offshore wind turbine. Marine environmental load was calculated per ISO standard and the margin of verticality error was calculated to be $L/{\infty}$(=0), L/300, L/200 and L/100. As a result of analysis, it was found that the maximum value of member force of the foundation with L/100 error increased about 7.2% compared to the monopile without verticality error.

The Effects of Clothing Consumption Value and Demographic Features on Clothing Disposal Behaviors (의복소비가치와 인구통계적 특성에 따른 의복처분행동)

  • Ahn, Soo-kyoung;Ryou, Eunjeong
    • Fashion & Textile Research Journal
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    • 제17권6호
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    • pp.956-964
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    • 2015
  • This study aims to investigate the relationship between consumers’ clothing consumption values, demographic features, and clothing disposal behaviors. The data were collected from 300 women aged between 20 and 59 through the online survey with the self-administered questionnaire. A series of exploratory and confirmative factor analysis was conducted to identify the dimensions of clothing consumption values and clothing disposition behaviors. Clothing consumption values consisted of six dimensions including conditional value, individuality value, fashion value, social value, practical value, and self-expression value. Clothing disposition behaviors were discovered as four dimensions such as discarding, giving, selling, and donating. A structural equation modeling analysis was employed to examine the relationship between clothing consumption values and disposition behaviors. While individuality value, fashion value, and practical value had a significantly positive impact on donating, giving, and discarding behaviors, both practical value and self-expression value negatively influenced discarding behavior. Fashion value negatively affected giving behavior. Employing a series of MANOVA, one-way ANOVA and sheffe's multiple range test, this study found that there were significant effects of age, marital status, monthly income, and monthly clothing expenses on giving and donating behaviors. This study suggests that fashion firms should be aware of clothing disposition in terms of social and environmental concerns and understand diverse consumer disposal behaviors and utilize them as a social marketing strategy.

Contact interface fiber section element: shallow foundation modeling

  • Limkatanyu, Suchart;Kwon, Minho;Prachasaree, Woraphot;Chaiviriyawong, Passagorn
    • Geomechanics and Engineering
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    • 제4권3호
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    • pp.173-190
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    • 2012
  • With recent growing interests in the Performance-Based Seismic Design and Assessment Methodology, more realistic modeling of a structural system is deemed essential in analyzing, designing, and evaluating both newly constructed and existing buildings under seismic events. Consequently, a shallow foundation element becomes an essential constituent in the implementation of this seismic design and assessment methodology. In this paper, a contact interface fiber section element is presented for use in modeling soil-shallow foundation systems. The assumption of a rigid footing on a Winkler-based soil rests simply on the Euler-Bernoulli's hypothesis on sectional kinematics. Fiber section discretization is employed to represent the contact interface sectional response. The hyperbolic function provides an adequate means of representing the stress-deformation behavior of each soil fiber. The element is simple but efficient in representing salient features of the soil-shallow foundation system (sliding, settling, and rocking). Two experimental results from centrifuge-scale and full-scale cyclic loading tests on shallow foundations are used to illustrate the model characteristics and verify the accuracy of the model. Based on this comprehensive model validation, it is observed that the model performs quite satisfactorily. It resembles reasonably well the experimental results in terms of moment, shear, settlement, and rotation demands. The hysteretic behavior of moment-rotation responses and the rotation-settlement feature are also captured well by the model.

Synergistic Effect of Urea and Lime Treatment of Wheat Straw on Chemical Composition, In Sacco and In Vitro Digestibility

  • Sirohi, S.K.;Rai, S.N.
    • Asian-Australasian Journal of Animal Sciences
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    • 제12권7호
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    • pp.1049-1053
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    • 1999
  • Chopped wheat straw (0.5-1.5 cm) was subjected to different treatment combinations in a $5{\times}4$ factorial arrangement involving the five levels of urea (0, 2, 3, 4 and 5%, w/w) and four levels of lime (0, 2, 4 and 6%, w/w) at 50% moisture and kept for 3 wk reaction period at about $35{^{\circ}C}$ in laboratory. Treated wheat straw samples were analyzed to study the associative effect of urea and lime on chemical composition, in sacco and in vitro digestibilities. Results showed that cell wall constituents (CWC) solubilized significantly (p<0.01) due to urea and lime treatment on one hand and substantially increase the crude protein (CP) on the other in wheat straw. The main effect on synergism of both chemicals was noticed on organic matter (OM), neutral detergent fibre (NDF), hemicellulose (HC), acid detergent lignin (ADL) and silica by solubilising their contents as a result of considerable increase in cell contents in treated wheat straw. The respective decreases were 5.45, 13.0, 37.23, 44.95 and 26.16% in different treatment combinations. The most interesting feature of the treatment was evident by increase in ash content on each level of lime application. CP content increase up to 12.78% due to urea treatment in comparison with untreated wheat straw (2.56%). The effect of solubilization of structural carbohydrates and increased crude protein due to synergistic effect of urea and lime were clearly seen on improved digestibility of OM and DM. The increase in ISOMD, ISDMD, and IVDMD were 21.67, 21.67, 16.24, and 17.5 units. The increase in digestibility were relative to additions of both chemicals and digestibility values increased with increasing levels of urea plus lime concentration in different treatment combination. The maximum improvement was noticed at 4% urea and 4% lime levels at 50% moisture for 3 wk reaction period in treated wheat straw.

Suppression of Dielectric Loss at High Temperature in (Bi1/2Na1/2)TiO3 Ceramic by Controlling A-site Cation Deficiency and Heat Treatment

  • Lee, Ju-Hyeon;Lee, Geon-Ju;Pham, Thuy-Linh;Lee, Jong-Sook;Jo, Wook
    • Journal of Sensor Science and Technology
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    • 제29권1호
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    • pp.7-13
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    • 2020
  • Dielectric capacitors are integral components in electronic devices that protect the electric circuit by providing modulated steady voltage. Explosive growth of the electric automobile market has resulted in an increasing demand for dielectric capacitors that can operate at temperatures as high as 400 ℃. To surpass the operation temperature limit of currently available commercial capacitors that operate in temperatures up to 125 ℃, Bi1/2Na1/2TiO3 (BNT), which has a large temperature-insensitive dielectric response with a maximum dielectric permittivity temperature of 300 ℃, was selected. By introducing an intentional A-site cation deficiency and post-heat treatment, we successfully manage to control the dielectric properties of BNT to use it for high-temperature applications. The key feature of this new BNT is remarkable reduction in dielectric loss (0.36 to 0.018) at high temperature (300 ℃). Structural, dielectric, and electrical properties of this newly developed BNT were systematically investigated to understand the underlying mechanism.

An Ultra-precision Lathe for Large-area Micro-structured Roll Molds (대면적 미세패턴 롤 금형 가공용 초정밀 롤 선반 개발)

  • Oh, Jeong Seok;Song, Chang Kyu;Hwang, Jooho;Shim, Jong Youp;Park, Chun Hong
    • Journal of the Korean Society for Precision Engineering
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    • 제30권12호
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    • pp.1303-1312
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    • 2013
  • We report an ultra-precision lathe designed to machine micron-scale features on a large-area roll mold. The lathe can machine rolls up to 600 mm in diameter and 2,500 mm in length. All axes use hydrostatic oil bearings to exploit the high-precision, stiffness, and damping characteristics. The headstock spindle and rotary tooling table are driven by frameless direct drive motors, while coreless linear motors are used for the two linear axes. Finite element method modeling reveals that the effects of structural deformation on the machining accuracy are less than $1{\mu}m$. The results of thermal testing show that the maximum temperature rise at the spindle outer surface is approximately $0.5^{\circ}C$. Finally, performance evaluations of the error motion, micro-positioning capability, and fine-pitch machining demonstrate that the lathe is capable of producing optical-quality surfaces with micron-scale patterns with feature sizes as small as $20{\mu}m$ on a large-area roll mold.

Structural Characteristics on InAs Quantum Dots multi-stacked on GaAs(100) Substrates

  • Roh, Cheong-Hyun;Park, Young-Ju;Kim, Eun-Kyu;Shim, Kwang-Bo
    • Journal of the Microelectronics and Packaging Society
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    • 제7권1호
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    • pp.25-28
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    • 2000
  • The InAs self-assembled quantun dots (SAQDS) were grown on a GaAs(100) substrate using a molecular beam epitaxy (MBE) technique. The InAs QDs were multi-stacked to have various layer structures of 1, 3, 6, 10, 15 and 20 layers, where the thickness of the GaAs spacer and InAs QD layer were 20 monolayers (MLs) and 2 MLs, respectively. The nanostructured feature was characterized by photoluminescence (PL) and scanning transmission electron microscopy (STEM). It was found that the highest PL intensity was obtained from the specimen with 6 stacking layers and the energy of the PL peak was split with increasing the number of stacking layers. The STEM investigation exhibited that the quantum dots in the 6 stacking layer structure were well aligned in vertical columns without any deflect generation, whereas the volcano-like deflects were formed vertically along the growth direction over 10 periods of InAs stacking layers.

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Transformation characteristics of stylobate and staircase of post-lintel Construction of Backje and Silla Style (백제계 및 신라계 가구식 기단과 계단의 시기별 변화특성)

  • Nam, Chang-Keun;Kim, Tai-Young
    • Journal of architectural history
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    • 제21권1호
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    • pp.99-118
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    • 2012
  • This study aims to classify the architectural formation of the Stylobate of and Staircase types of Post-Lintel Construction in Backje style and Silla style and also to figure out their specific elements by periods and transformation characteristics. The scope of this study was restricted to architectural remains between the Three Kingdom period and the Goryeo period. To progress the investigation, the study classified remains in a similar type by period and type, and then and analyzed its character based on formation method and specific factors of subsidiary materials. As a result, its type can be classified as Backje type(I), Silla type(II) and Mixed type(III). Regionally, it is found that Woongjin, Sabi and surroundings in the capital of Backje, Gyeongju and main towns in the capital of Silla, and Gaeseong and main towns in the capital of Goryeo. In particular, type III has the characteristics of type I and II simultaneously, which has one or two layers Jangdaeseok stone between the foundation stone of stylobate and plate stone, and tends to be decorative when Taengjuseok stone is installed. For types of staircase, it could be classified as 6~7C Backje type(I), 7~9C Silla type(II) and 9C Mixed type(III) according to the formation method of Somaetdol (banister of stone stair). And from the 9th century on, decorated Somaetdol stone type(IV) of 1/4 circle shape began to appear. The common feature of stylobate of post-lintel and staircase is that it became simplified, abbreviated and decorative. It seems to be intended to secure simplicity of construction or structural stability.