• Structural Engineering and Mechanics
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• 제85권5호
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• pp.655-664
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• 2023

Reinforced concrete (RC) shear wall structures are one of the most widely used structural systems to resist seismic loading all around the world. Although there have been several efforts to provide conceptually simple procedures to reasonably assess the seismic demands of structures over recent decades, it seems that lesser effort has been put on a number of structural forms such as RC shear wall structures. Therefore, this study aims to represent a simple linear response spectrum-based method which can acceptably predict the nonlinear displacements of a non-ductile RC shear wall structure subjected to an individual ground motion record. An effective period and an equivalent damping ratio are introduced as the dynamic characteristics of an equivalent linear SDOF system relevant to the main structure. By applying the fundamental mode participation factor of the original MDOF structure to the linear spectral response of the equivalent SDOF system, an acceptable estimation of the nonlinear displacement response is obtained. Subsequently, the accuracy of the proposed method is evaluated by comparison with another approximate method which is based on linear response spectrum. Results show that the proposed method has better estimations for maximum nonlinear responses and is more utilizable and applicable than the other one.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.527-532
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• 2002

Near field ground motions contain distinct and large amplitude pulses in both velocity and displacement. This paper investigates characteristics of near field earthquakes and their effects on seismic demands. 20 EQGMs were selected for this purpose that satisfied 5 conditions for Near field motion. Among them ten EQGMs have one distinct peak velocity pulse in the velocity time history. In this study the responsed are Linear Elastic Response Spectrum(LERS), Response Modification Factor(R) and Inelastic Response Spectrum(IRS). The effect of the selection of Near field EQGMs on these response parameters are investigated.

• Structural Engineering and Mechanics
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• 제41권2호
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• pp.243-262
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• 2012

Nonlinear static analysis as an essential part of performance based design is now widely used especially at design offices because of its simplicity and ability to predict seismic demands on inelastic response of buildings. Since the accuracy of nonlinear static procedures (NSP) to predict seismic demands of buildings affects directly on the entire performance based design procedure, therefore lots of research has been performed on the area of evaluation of these procedures. In this paper, one of the popular NSP, FEMA356, is evaluated and compared with modal pushover analysis. The ability of these procedures to simulate seismic demands in a set of reinforced concrete (RC) buildings is explored with two level of base acceleration through a comparison with benchmark results determined from a set of nonlinear time history analyses. According to the results of this study, the modal pushover analysis procedure estimates seismic demands of buildings like inter story drifts and hinges plastic rotations more accurate than FEMA356 procedure.

• International Journal of Railway
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• 제5권4호
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• pp.139-143
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• 2012

In Korea, almost 700 industrial parks are under operation. Generally, industrial parks consist of national industrial parks and local industrial parks which are managed by a central government and by local governments respectively. The developing countries such as Korea, China and Vietnam etc. have constructed many industrial parks, which result in the change of land use pattern and also affect future trip demands. Therefore, in estimating traffic demands, it is very important to consider the industrial park development. This study aims to improve the methodology in estimating a freight trip generation rate with the data based on a nationwide commodity freight survey. The result showed that it is desirable to apply freight trip generation rate by the industry sector in estimating freight trip generations and using the production area of firm as an indicator. Specially, the reliability of the rates through a survey could be made sure because a sample rate based on firms in industrial parks was over 25% and the response rate was over 67%. The sample rate and response rate are very superior as compared to surveys conducted in many other countries. Because industrial parks have significant effects on forecasting transportation demand in pre-feasibility studies of transport and logistics projects, it is expected that the accuracy of freight trip demands would be improved through the results of this study.

• 한국지진공학회논문집
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• 제11권4호
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• pp.53-63
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• 2007

Seismic design codes are developed mainly based on the observation of the behavior of structures in the high seismicity regions where structures may experience significant amount of inelastic deformations and major earthquakes may result in structural damages in a vast area. Therefore, seismic loads are reduced in current design codes for building structures using response modification factors which depend on the ductility capacity and overstrength of a structural system. However, structures in low seismicity regions, subjected to a minor earthquake, will behave almost elastically because of the larger overstrength of structures in low seismicity regions such as Korea. Structures in low seismicity regions may have longer periods since they are designed to smaller seismic loads and main target of design will be minor or moderate earthquakes occurring nearby. Ground accelerations recorded at stations near the epicenter may have somewhat different response spectra from those of distant station records. Therefore, it is necessary to verify if the seismic design methods based on high seismicity would he applicable to low seismicity regions. In this study, the adequacy of design spectra, period estimation and response modification factors are discussed for the seismic design in low seismicity regions. The response modification factors are verified based on the ductility and overstrength of building structures estimated from the farce-displacement relationship. For the same response modification factor, the ductility demand in low seismicity regions may be smaller than that of high seismicity regions because the overstrength of structures may be larger in low seismicity regions. The ductility demands in example structures designed to UBC97 for high, moderate and low seismicity regions were compared. Demands of plastic rotation in connections were much lower in low seismicity regions compared to those of high seismicity regions when the structures are designed with the same response modification factor. Therefore, in low seismicity regions, it would be not required to use connection details with large ductility capacity even for structures designed with a large response modification factor.

• International Journal of Human Ecology
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• 제16권1호
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• pp.11-23
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• 2015

Although Korean international students/scholars are among the largest groups of international students/scholars on most campuses in the United States, little is known about what types of demands their families face and how they adapt successfully in the face of demands. The purpose of this study was to explore family resilience, which consists of family demands, capabilities, and adaptation, perceived by Korean international student/scholar families, being theoretically guided by the Family Adjustment and Adaptation Response (FAAR) model. Data were collected through face-to-face interviews with couple informants. Following procedures of theory-based content analysis, data were analyzed using key FAAR concepts. Findings showed that most informants reported normative types of family demands such as hardships due to childcare; primary family capabilities were "maintaining social integration," "affective and instrumental communication," and "family cohesiveness," and "nurturance, education, and socialization" was the primary family adaptation mode. New categories under family capabilities, "religious commitment" and "transnational family support" were developed. The results suggest that there is a unique set of family capabilities that contribute to the successful adaptation of Korean international student/scholar families. Implications and limitations are discussed.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1999년도 춘계학술발표논문집 논문집
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• pp.139-145
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• 1999

In current study on 8 college students there was examined modulation of eyeblink (as measured by integrated EMG of m.orbicularis oculi) and skin conductance response (SCR) to an acoustic startle probe (85 dB[A] white noise) by attending to task presented in auditory modality (to memorize words for further recognition) and entire performance of the word recognition test. Both eyeblink magnitude and SCR amplitude and rise time to startle probes were modified (larger magnitude of EMG peak, lower amplitude and shorter rise time of SCR) during attending to task as compared to performance on test. Results are interpreted n terms of modification of electrodermal and eyeblink components of startle and orienting reflexes by task characteristics (passive versus active efforts), attentional demands and aversiveness of experimental situation. However, eyeblink startle response manifested potentiation during attending to task, while SCR demonstrated attenuation. There are discussed implications of startle modulatioas a potentially sensitive probe of situational demands in stress research and also are considered prospects for further studies.

• PNF and Movement
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• 제6권1호
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• pp.41-51
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• 2008

Purpose : This paper reviews evidence supporting adaptive plasticity in skeletal muscle fibers induced by various exercise training and neuromuscular activity. Result : Skeletal muscle fiber demonstrates a remarkable adaptability and can adjust its physiologic and contractile makeup in response to alterations in functional demands. This adaptive plasticity results from the ability of muscle fibers to adjust their molecular, functional, and contractile properties in response to altered physiological demands, such as changes in exercise patterns and mechanical loading. The process of activity-dependent plasticity in skeletal muscle involves a multitude of signalling mechanisms initiating replication of specific genetic sequences, enabling subsequent translation of the genetic message and ultimately generating a series of myosin heavy chain isoform. Conclusions : Knowledge of the mechanisms and interaction of activity-dependent adaptive pathways in skeletal muscle is important for our understanding of the synthesis of muscle myosin protein, maintenance of metabolic and functional capacity with physical activity, and therapeutic intervention for functional improvement.

• Earthquakes and Structures
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• 제20권3호
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• pp.239-260
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• 2021

Torsional response of buildings is attributed to poor structural configurations in plan, which arises due to two factors - torsional eccentricity and torsional flexibility. Usually, building codes address effects due to the former. This study examines both of these effects. Buildings with torsional eccentricity (e.g., those with large eccentricity) and with torsional flexibility (those with torsional mode as a fundamental mode) demand large deformations of vertical elements resisting lateral loads, especially those along the building perimeter in plan. Lateral-torsional responses are studied of unsymmetrical buildings through elastic and inelastic analyses using idealised single-storey building models (with two degrees of freedom). Displacement demands on vertical elements distributed in plan are non-uniform and sensitive to characteristics of both structure and earthquake ground motion. Limits are proposed to mitigate lateral-torsional effects, which guides in proportioning vertical elements and restricts amplification of lateral displacement in them and to avoid torsional mode as the first mode. Nonlinear static and dynamic analyses of multi-storey buildings are used to validate the limits proposed.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 1980년도 학술대회지
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• pp.237-244
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• 1980