• Title/Summary/Keyword: Design-time history

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Modified Nonlinear Static Pushover Procedures of MDOF Bridgesfor Seismic Performance Evaluation (내진성능평가를 위한 다자유도 교량의 수정 비선형 등가정적해석법)

  • Cho, Chang-Geun;Kim, Young-Sang;Bae, Soo-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.10 no.4
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    • pp.175-184
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    • 2006
  • Two methods of the nonlinear static pushover analysis have been presented for the performance-based seismic design and evaluation of MDOF continuous bridges. Guidelines for buildings presented in FEMA-273 applying the Displacement Coefficient Method (DCM) and in ATC applying the Capacity Spectrum Method(CSM) have been modified for MDOF bridges. Two methods are compared with the time- history analysis. The lateral load distribution pattern for seismic loads has been examined in the static pushover analysis. The force-based fiber frame finite element has been implemented in the modeling of reinforced concrete piers.

Plastic hinge length of RC columns considering soil-structure interaction

  • Mortezaei, Alireza
    • Earthquakes and Structures
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    • v.5 no.6
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    • pp.679-702
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    • 2013
  • During an earthquake, soils filter and send out the shaking to the building and simultaneously it has the role of bearing the building vibrations and transmitting them back to the ground. In other words, the ground and the building interact with each other. Hence, soil-structure interaction (SSI) is a key parameter that affects the performance of buildings during the earthquakes and is worth to be taken into consideration. Columns are one of the most crucial elements in RC buildings that play an important role in stability of the building and must be able to dissipate energy under seismic loads. Recent earthquakes showed that formation of plastic hinges in columns is still possible as a result of strong ground motion, despite the application of strong column-weak beam concept, as recommended by various design codes. Energy is dissipated through the plastic deformation of specific zones at the end of a member without affecting the rest of the structure. The formation of a plastic hinge in an RC column in regions that experience inelastic actions depends on the column details as well as soil-structure interaction (SSI). In this paper, 854 different scenarios have been analyzed by inelastic time-history analyses to predict the nonlinear behavior of RC columns considering soil-structure interaction (SSI). The effects of axial load, height over depth ratio, main period of soil and structure as well as different characteristics of earthquakes, are evaluated analytically by finite element methods and the results are compared with corresponding experimental data. Findings from this study provide a simple expression to estimate plastic hinge length of RC columns including soil-structure interaction.

Seismic assessment of R/C residential buildings with infill walls in Turkey

  • Korkmaz, Kasim Armagan;Kayhan, Ali Haydar;Ucar, Taner
    • Computers and Concrete
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    • v.12 no.5
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    • pp.681-695
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    • 2013
  • In 1999 Marmara and 2011 Van earthquakes in Turkey, majority of the existing buildings either sustained severe damage or collapsed. These buildings include masonry infill walls in both the interior and exterior R/C frames. The material of the masonry infill is the main variant, ranging from natural stones to bricks and blocks. It is demanding to design these buildings for satisfactory structural behavior. In general, masonry infill walls are considered by its weights not by interaction between walls and frames. In this study, R/C buildings with infill walls are considered in terms of structural behavior. Therefore, 5 and 8-story R/C buildings are regarded as the representative models in the analyses. The R/C representative buildings, both with and without infill walls were analyzed to determine the effects of structural behavior change. The differences in earthquake behavior of these representative buildings were investigated to determine the effects of infill walls leading structural capacity. First, pushover curves of the representative buildings were sketched. Aftermath, time history analyses were carried out to define the displacement demands. Finally, fragility analyses were performed. Throughout the fragility analyses, probabilistic seismic assessment for R/C building structures both with and without infill walls were provided. In this study, besides the deterministic assessment methodology, a probabilistic approach was followed to define structural effect of infill walls under seismic loads.

Pastiche in the late Capitalism Fashion (후기자본주의 사회의 패션에 나타난 혼성모방)

  • 김민자
    • Journal of the Korean Society of Costume
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    • v.50
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    • pp.69-84
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    • 2000
  • Th purpose of this study is three folds: to analyze postmodern fashion through the notion of pastiche to enhance an understanding of uncertain and confused situation in the late 1990s and to suggest a way of approach to creativity and originality in recent fashion design. The results can be summarized as follows: 1. Pastiche is an art work that borrows some parts of other artists authentic works and recombines them thus imitating their style technique or motifs selfconciously. 2. Pastiche is based onthe Deconstruction theory: the end of art as a result of deconstruction of the subject the collapse of the meaning the loss of history: the late Capitalism in which reality becomes chage into images or simulacre. 3. Pastiche represented by the death of author which means the exhaustion of creativity is shown in the fashion borrowing subculture styles and art works or religious images. Pastiche fashion which is equal to the play of signifiers floated as image is shown as graffiti and objects Time and space pastiche fashion can be explained by historical eclectism and ethnic looks, Finally pastiche means not the fixed aspect but the open concept of indeterminate condition which includes " anything goes" through the coesistence of various style in pastiche fashion.

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A Study on the Optimization of the Torsional Vibration Using DFFSS Method for DI Diesel Engine (직접분사방식 디젤엔진의 6시그마 기법을 적용한 비틀림 최적화에 대한 연구)

  • Kim, Jang-Su;Koh, Jang-Joo;Lee, Chi-Woo
    • Journal of the Korean Society of Industry Convergence
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    • v.15 no.1
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    • pp.13-19
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    • 2012
  • Due to a low stiffness of cranktrain and a failure experience from a history within short development time, a viscous torsional vibration damper was applied in order to reduce the torsional vibration and keep the high reliability for the durability of cranktrain system in the direct injection diesel engine. As an improvement of the crankshaft stiffness by increasing the diameter of main and pin journal, a rubber type damper could be considered. In this study, the control factors of rubber damper, the moment of inertia ring, stiffness of damper and damping coefficient of ring, were investigated by DFSS method through the analysis work and the measurement in the real engine condition.

Response Spectra of Structure Installed Frictional Damping System (마찰형 감쇠를 갖는 구조물의 응답 스펙트럼)

  • Park, Ji-Hun;Youn, Kyong-Jo;Min, Kyung-Won;Lee, Sang-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.893-897
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    • 2006
  • Structures with additional frictional damping system have strong nonlinearity that the dynamic behavior is highly affected. by the relative magnitude between frictional force and excitation load. In this study, normalized response spectra of the structures with non-dimensional friction force are obtained through nonlinear time history analyses of the mass-normalized single degree of freedom systems using 20 ground motion data recorded on rock site. The variation of the control performance of frictional damping system is investigated in terms of the dynamic load and the structural natural period, of which effects were not considered in the previous studies. Least square curve fitting equations are presented for describing those normalized response spectrum and optimal non-dimensional friction forces are obtained for controlling the peak displacement and absolute acceleration of the structure based on the derivative of the curve fitted design spectrum.

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Analysis on running safety of train on bridge with wind barriers subjected to cross wind

  • Zhang, T.;Xia, H.;Guo, W.W.
    • Wind and Structures
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    • v.17 no.2
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    • pp.203-225
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    • 2013
  • An analysis framework for vehicle-bridge dynamic interaction system under turbulent wind is proposed based on the relevant theory of wind engineering and dynamics. Considering the fluctuating properties of wind field, the stochastic wind velocity time history is simulated by the Auto-Regressive method in terms of power spectral density function of wind field. The bridge is represented by three-dimensional finite element model and the vehicle by a multi-rigid-body system connected by springs and dashpots. The detailed calculation formulas of unsteady aerodynamic forces on bridge and vehicle are derived. In addition, the form selection of wind barriers, which are applied as the windbreak measures of newly-built railways in northwest China, is studied based on the suggested evaluation index, and the suitable values about height and porosity rate of wind barriers are studied. By taking a multi-span simply-supported box-girder bridge as a case study, the dynamic response of the bridge and the running safety indices of the train traveling on the bridge with and without wind barriers are calculated. The limit values of train speed with respect to different wind velocities are proposed according to the allowance values in the design code.

Contribution of non-structural brick walls distributions on structures seismic responses

  • Farghaly, Ahmed Abdelraheem;Rahim, Hamdy H.A. Abdel
    • Earthquakes and Structures
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    • v.5 no.5
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    • pp.553-570
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    • 2013
  • Using of masonry infill as partitions, in flat slab frame buildings is a common practice in many parts of the world. The infill is, generally, not considered in the design and the buildings are designed as bare frames. More of fundamental information in the effect of masomary infill on the seismic performance of RC building frames is in great demand for structural engineers. Therefore the main aim of this research is to evaluate the seismic performance of such buildings without (bare frame) and with various systems of the masonary infill. For this purpose, thirteen three dimensional models are chosen and analyzed by SAP2000 program. In this study the stress strain relation model proposed by Crisafulli for the hysteric behaviour of masonary subjected to cyclic loading is used. The results show that the nonstructural masonary infill can impart significant increase global strength and stiffness of such building frames and can enhance the seismic behaviour of flat slab frame building to large extent depending on infill wall system. As a result great deal of insight has been obtained on seismic response of such flat slab buildings which enable the structural engineer to determine the optimum position of infill wall between the columns.

Design and Implement of Multi-agent System for Internet Auction (인터넷 경매를 위한 멀티 에이전트 시스템의 설계 및 구현)

  • 김은영;김태석;김광휘
    • Journal of the Korea Computer Industry Society
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    • v.2 no.3
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    • pp.321-328
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    • 2001
  • Existing internet auction systems have adopted the form which gives a win to the auction bidder who proposes the top bid price for the goods posted on the auction board. But they haven't been satisfying the automatical one-step processing for user’s convenience because they must require continuous care of user for bidding and checking as well as neglecting the convenience of user interface while participating in the electronic bidding system. The agent push mail to a auctioneer information that able to get how much profit as calculate duration time and start price with bidding history stored database. So, this thesis propose a multi-agent system in internet auction that generate the highest margin for auctioneer’s goods.

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A study on the descriptive cataloging of serial title changes (지명변경자료의 기술목록법에 관한 연구)

  • 윤희윤
    • Journal of Korean Library and Information Science Society
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    • v.22
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    • pp.61-93
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    • 1995
  • This paper discussed which of the three basic entries of serials that changed their titles-earliest, latest, or successive entry cataloging-is the most efficient, informative, and economical in a manual and an online environment. The results of the study are as follow: 1. Earliest entry cataloging or as an alternative, successive entry cataloging advocated by Cutter in 1976 was replaced in ALA Cataloging Rules by latest entry cataloging and with AACR1 and AACR2, latest entry cataloging was replaced by successive entry cataloging again. 2. Entry method of serial cataloging should be determined in consideration of goals of catalog, efficiency of catalog retrieval, theoretical and practical standpoint of entry methods, average cataloging time and cost, the state of adaption. 3. In a card catalog environment, if the numbering and class number of the serial that title proper changed into initials itself continue and the title history must not be too complicated, the serial is desirable to entry under the latest title. Except for above case, successive entry cataloging enables serials to be more quickly and economically made available to users than with either earliest or latest entry cataloging. 4. In an automated catalog environment, successive entry cataloging has more potential of satisfying and impairs the efficiency of both accessing and processing a library's serials collection. However, when initial cataloging by MARC format is done, careful screen design and complex programming will be needed. And subfield containing the local record number should be added to the programming means to link the various records together, i.e., 780 (preceding title) and 785 (succeeding title) fields for all related titles.

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