• 제목/요약/키워드: Non-response

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Nonlinear seismic response of a masonry arch bridge

  • Sayin, Erkut
    • Earthquakes and Structures
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    • 제10권2호
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    • pp.483-494
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    • 2016
  • Historical structures that function as a bridge from past to present are the cultural and social reflections of societies. Masonry bridges are one of the important historical structures. These bridges are vulnerable against to seismic action. In this study, linear and non-linear dynamic analyses of historical Nadir Bridge are assessed. The bridge is modelled with three dimensional finite elements. For the seismic effect, artificial acceleration records are generated considering the seismic characteristics of the region where the bridge is located. Seismic response of the bridge is investigated.

벡터투영법을 이용한 응답면기법에 관한 연구 (A Study on Response Surface Method Using the Vector Projection Technique)

  • 김상효;나성원;김우곤
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1994년도 가을 학술발표회 논문집
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    • pp.167-174
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    • 1994
  • In this study, an improved response surface method is proposed. By using gradient projection method, the sampling points for creating response surface are evaluated at the region close to the failure surface. This points are combined with linear response surface function and Rackwitz-Fiessler algorithm. Also, a method controlling the range of selecting sampling points considering the non-linearity of the limit states is proposed to reduce the error produced by approximating the non-linear limit state to linear response surface. With the examples the result of the proposed method is found to be more accurate and efficient than the previous response surface method.

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Response of rigid footing on reinforced granular fill over soft soil

  • Ramu, K.;Madhav, Madhira R.
    • Geomechanics and Engineering
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    • 제2권4호
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    • pp.281-302
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    • 2010
  • An extended model for the response of a rigid footing on a reinforced foundation bed on super soft soil is proposed by incorporating the rough membrane element into the granular bed. The super soft soil, the granular bed and the reinforcement are modeled as non-linear Winkler springs, non-linear Pasternak layer and rough membrane respectively. The hyperbolic stress-displacement response of the super soft soil and the hyperbolic shear stress-shear strain response of the granular fill are considered. The finite deformation theory is used since large settlements are expected to develop due to deformation of the super-soft soil. Parametric studies quantify the effect of each parameter on the stress-settlement response of the reinforced foundation bed, the settlement and tension profiles.

A Pooled Analysis on Crizotinib in Treating Chinese Patients with EML4-ALK Positive Non-small-cell Lung Cancer

  • Li, Yang;Huang, Xin-En
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권11호
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    • pp.4797-4800
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    • 2015
  • Background: This analysis was conducted to evaluate the efficacy and safety of crizotinib based regimens in treating Chinese patients with EML4-ALK positive non-small-cell lung cancer. Materials and Methods: Clinical studies evaluating the efficacy and safety of crizotinib based regimens on response and safety for Chinese patients with EML4-ALK positive non-small-cell lung cancer were identified by using a predefined search strategy. Pooled response rate (RR) of treatment were calculated. Results: In crizotinib based regimens, 3 clinical studies which including 128 Chinese patients with EML4-ALK positive non-small-cell lung cancer and treated with crizotinib based regimen were considered eligible for inclusion. Pooled analysis suggested that, in all patients, the pooled RR was 59.3% (76/128) in crizotinib based regimens. ALT/AST mild visual disturbances, nausea, and vomiting were the main side effects. No treatment related death occurred in these crizotinib based treatments. Conclusions: This pooled analysis suggests that crizotinib based regimens are associated with good response rate and accepted toxicities in treating Chinese patients with EML4-ALK positive non-small-cell lung cancer.

AIS상 통신기 대기채널 전시를 통한 선박안전 향상 방안

  • 김종진;박광호;엄윤상;김갑석
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2013년도 추계학술대회
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    • pp.192-195
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    • 2013
  • AIS가 상용화 됨에 따라 더 효율적인 관제서비스의 제공이 가능해졌고, 선박간의 통항에도 신속한 판단을 가능하게 해주었다. 해상에서의 상호의사소통은 대부분 통신기를 통해 이루어지는 바 관제채널 미청취 선박 및 무응답선에 대해서는 관제서비스의 제공이 불가능하고 선박간의 상호 의사소통에 있어서도 어려움을 야기시키는 주원인이 되고 있다. 이에 대한 대책으로서 AIS상 통신기 대기채널을 전시함으로서 실시간으로 각 선박의 통신기 대기채널을 확인함으로서 관제채널 미청취 선박이나 무응답선에 대한 통신기 응답률을 향상시켜 선박안전 향상을 도모하고자 한다.

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상판과 교대의 충돌을 고려한 사교의 비선형 지진거동 해석 (Nonlinear Seismic Behavior Analysis of Skewed Bridges Considering Pounding Between Deck and Abutment)

  • 강승우;최광규;송시영;손민규
    • 한국지진공학회논문집
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    • 제20권5호
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    • pp.301-310
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    • 2016
  • There are differences in seismic behavior between non-skewed bridges and skewed bridges due to in-plane rotations caused by pounding between the skewed deck and its abutments during strong earthquake. Many advances have been made in developing design codes and guidelines for dynamic analyses of non-skewed bridges. However, there remain significant uncertainties with regard to the structural response of skewed bridges caused by unusual seismic response characteristics. The purpose of this study is performing non-linear time history analysis of the bridges using abutment-soil interaction model considering pounding between the skewed deck and its abutments, and analyzing global seismic behavior characteristics of the skewed bridges to assess the possibility of unseating. Refined bridge model with abutment back fill, shear key and elastomeric bearing was developed using non-linear spring element. In order to evaluate the amplification of longitudinal and transverse displacement response, non-linear time history analysis was performed for single span bridges. Far-fault and near-fault ground motions were used as input ground motions. According to each parameter, seismic behavior of skewed bridges was evaluated.

패널자료의 무응답 대체법 (Non-Response Imputation for Panel Data)

  • 박기덕;신기일
    • Communications for Statistical Applications and Methods
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    • 제17권6호
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    • pp.899-907
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    • 2010
  • 무응답 대체(non-response imputation) 방법에 관한 많은 이론과 방법이 제안되었으며 실제 자료 분석에 이용되고 있다. 흔히 횡단면 무응답 대체를 위하여 다중대체법(multiple imputation)이 사용되고 있으며 2차년도 이상의 패널자료에는 종시점회귀대체법(cross-wave regression imputation)이 사용되고 있다. 본 연구에서는 패널자료 분석을 위하여 종시점회귀대체법의 일반형태인 시계열 대체법과 횡단면 무응답 대체법을 결합한 시계열-횡단면 다중 대체법을 제안하였다. 노동부의 매월노동통계 자료를 이용하여 제안한 방법과 기존의 종시점회귀대체법을 비교하여 우수함을 보였다.

CCQC modal combination rule using load-dependent Ritz vectors

  • Xiangxiu Li;Huating Chen
    • Structural Engineering and Mechanics
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    • 제87권1호
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    • pp.57-68
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    • 2023
  • Response spectrum method is still an effective approach for the design of buildings with supplemental dampers. In practice, complex complete quadratic combination (CCQC) rule is always used in the response spectrum method to consider the effect of non-classical damping. The conventional CCQC rule is based on exact complex mode vectors. Sometimes the calculated complex mode vectors may be not excited by the external loading and errors in the structural responses always arise due to the mode truncation. Load-dependent Ritz (LDR) vectors are associated with the external loading and LDR vectors not excited can be automatically excluded. Also, contributions of higher modes are implicitly contained in the LDR vectors in terms of static responses. To improve the calculation efficiency and accuracy, LDR vectors are introduced in the CCQC rule in the present study. Firstly, the generation procedure of LDR vectors suitable for non-classical damping system is presented. Compared to the conventional LDR vectors, the LDR vectors herein are complex-valued and named as complex LDR (CLDR) vectors. Based on the CLDR vectors, the CCQC rule is then rederived and an improved response spectrum method is developed. Finally, the effectiveness of the proposed method in this paper is verified through three typical non-classical damping buildings. Numerical results show that the CLDR vector is superior to the complex mode with the same number in the calculation. Since the generation of CLDR vectors requires less computational cost and storage space, the method proposed in this paper offers an attractive alternative, especially for structures with a large number of degrees of freedom.

An effective load increment method for multi modal adaptive pushover analysis of buildings

  • Turker, K.;Irtem, E.
    • Structural Engineering and Mechanics
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    • 제25권1호
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    • pp.53-73
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    • 2007
  • In this study, an effective load increment method for multi modal adaptive non-linear static (pushover) analysis (NSA) for building type structures is presented. In the method, lumped plastisicity approach is adopted and geometrical non-linearties (second-order effects) are included. Non-linear yield conditions of column elements and geometrical non-linearity effects between successive plastic sections are linearized. Thus, load increment needed for formation of plastic sections can be determined directly (without applying iteration or step-by-step techniques) by using linearized yield conditions. After formation of each plastic section, the higher mode effects are considered by utilizing the essentials of traditional response spectrum analysis at linearized regions between plastic sections. Changing dynamic properties due to plastification in the system are used on the calculation of modal lateral loads. Thus, the effects of stiffness changes and local mechanism at the system on lateral load distribution are included. By using the proposed method, solution can be obtained effectively for multi-mode whereby the properties change due to plastifications in the system. In the study, a new procedure for determination of modal lateral loads is also proposed. In order to evaluate the proposed method, a 20 story RC frame building is analyzed and compared with Non-linear Dynamic Analysis (NDA) results and FEMA 356 Non-linear Static Analysis (NSA) procedures using fixed loads distributions (first mode, SRSS and uniform distribution) in terms of different parameters. Second-order effects on response quantities and periods are also investigated. When the NDA results are taken as reference, it is seen that proposed method yield generally better results than all FEMA 356 procedures for all investigated response quantities.

Dysfunctional Social Reinforcement Processing in Disruptive Behavior Disorders: An Functional Magnetic Resonance Imaging Study

  • Hwang, Soonjo;Meffert, Harma;VanTieghem, Michelle R.;Sinclair, Stephen;Bookheimer, Susan Y.;Vaughan, Brigette;Blair, R.J.R.
    • Clinical Psychopharmacology and Neuroscience
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    • 제16권4호
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    • pp.449-460
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    • 2018
  • Objective: Prior functional magnetic resonance imaging (fMRI) work has revealed that children/adolescents with disruptive behavior disorders (DBDs) show dysfunctional reward/non-reward processing of non-social reinforcements in the context of instrumental learning tasks. Neural responsiveness to social reinforcements during instrumental learning, despite the importance of this for socialization, has not yet been previously investigated. Methods: Twenty-nine healthy children/adolescents and 19 children/adolescents with DBDs performed the fMRI social/non-social reinforcement learning task. Participants responded to random fractal image stimuli and received social and non-social rewards/non-rewards according to their accuracy. Results: Children/adolescents with DBDs showed significantly reduced responses within the caudate and posterior cingulate cortex (PCC) to non-social (financial) rewards and social non-rewards (the distress of others). Connectivity analyses revealed that children/adolescents with DBDs have decreased positive functional connectivity between the ventral striatum (VST) and the ventromedial prefrontal cortex (vmPFC) seeds and the lateral frontal cortex in response to reward relative to non-reward, irrespective of its sociality. In addition, they showed decreased positive connectivity between the vmPFC seed and the amygdala in response to non-reward relative to reward. Conclusion: These data indicate compromised reinforcement processing of both non-social rewards and social non-rewards in children/adolescents with DBDs within core regions for instrumental learning and reinforcement-based decision-making (caudate and PCC). In addition, children/adolescents with DBDs show dysfunctional interactions between the VST, vmPFC, and lateral frontal cortex in response to rewarded instrumental actions potentially reflecting disruptions in attention to rewarded stimuli.