• Title/Summary/Keyword: consistent response

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Structural Vibration Characteristics of a MW-Class Wind Turbine Tower Considering Earthquake Base Excitation (지진기반 가진효과를 고려한MW 급 풍력발전기 타워의 구조진동 특성연구)

  • Kim, Dong-Man;Park, Kang-Kyun;Kim, Dong-Hyun;Kim, Su-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.04a
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    • pp.616-620
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    • 2009
  • Modern wind turbines have been mainly erected in region where earthquake are rare or normally weak, especially Korea was thought as safety zone from earthquake. But recently, the earthquake occurs more and more frequently. So, the wind turbine design is required the structural and functional stability under the earthquake. The earthquake can influence normal operation, even if a weak earthquake. There are two ways to review the design under earthquake using Computer Applied Engineering (CAE). One is the Response Spectrum Analysis (RSA) the other is Time History Analysis (THA). In this research, dynamic response on time is obtained under the earthquake by taking into account ground accelerogram consistent with the relevant standards applied to the turbine foundation.

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A Design Method for Dynamic Systems Considering Statistical Properties (동적 시스템의 통계적 특성을 고려한 설계방법론)

  • Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.373-382
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    • 2008
  • A method to investigate the design variable tolerance effects on the variances of the response, the characteristics, and the performance of a mechanical system is presented in this paper. The Monte-Carlo method has been conventionally employed to achieve such goals. However, the Monte-Carlo method has some serious drawbacks related to the computation time and the consistent solution convergence. To resolve the drawbacks of the method, a method employing sensitivity information is proposed. Sensitivity equations for a mechanical system are obtained analytically by differentiating the multi-body formulation with respect to a design variable. By using the chain rule along with the sensitivity information, the variances of the response, the characteristics, and the performance of a dynamic system can be calculated.

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Ergonomic Considerations for the Design of a CRT-based Process Control System (CRT 방식 생산공정 제어용 계장시스템 설비의 인간공학적 고찰)

  • Chung, Min-Keun;Choi, Jae-Hyun;Jung, Eui-Seung
    • Journal of Korean Institute of Industrial Engineers
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    • v.16 no.2
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    • pp.11-21
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    • 1990
  • With a general trend toward larger and more complex systems with centralized control, an operator's role of supervisory decision making in the control room becomes more important. Identification of potential man-machine interface (MMI) problems with CRT-based process control systems was attempted using a structured questionnaire survey. Based on the survey results, a laboratory experiment was carried out to investigate the performance of alarm detection on a process control CRT display. The user performance was measured in terms of reaction time from the onset of an alarm sound until the completion of predefined response procedures. The results revealed that for a highly complex tasks, mean reaction time ($\bar{RT}$) with a color consistent display was 10.5% faster than that with the original display, and $\bar{RT}$ with a grouped display was reduced by 8.2% in comparison with the color consistent display.

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A physically consistent stress-strain model for actively confined concrete

  • Shahbeyk, Sharif;Moghaddam, Mahshid Z.;Safarnejad, Mohammad
    • Computers and Concrete
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    • v.20 no.1
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    • pp.85-97
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    • 2017
  • With a special attention to the different stages of a typical loading path travelled in a fluid confined concrete test, this paper introduces a physically consistent model for the stress-strain curve of actively confined normal-strength concrete in the axial direction. The model comprises of the five elements of: (1) a criterion for the peak or failure strength, (2) an equation for the peak strain, (3) a backbone hydrostatic curve, (4) a transient hardening curve linking the point of departure from the hydrostatic curve to the failure point, and finally (5) a set of formulas for the post-peak region. Alongside, relevant details and shortcomings of existing models will be discussed in each part. Finally, the accuracy and efficiency of the proposed model have been verified in a set of simulations which compare well with the experimental results from the literature.

The Stomach's Communication with Its Related Acupoints, and the "Intelligent Tissue" Hypothesis

  • Kovich, Fletcher
    • Journal of Acupuncture Research
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    • v.36 no.1
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    • pp.21-27
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    • 2019
  • Background: The intelligent tissue hypothesis holds that an organ's states (be it normal function or stressed states) are reflected in real time at its related acupuncture points (acupoints), causing physical, real-time changes in the local tissue. The experiment was devised to test this. Methods: The patient drank chilled water while the impedance at 6 stomach-related acupoints was monitored in real time (sample rate of 1 kHz). Any changes in the local tissue at the acupoints ought to be reflected in changes in the impedance. Results: The impedance at every test acupoint showed a response to the chilled water being ingested. Also, the duodenal pacesetter and the stomach's slow waves were clearly visible in the impedance pattern at all the acupoints. Conclusion: Hence, many separate details of the stomach's function were reflected at these acupoints. The duodenal features were consistent with the traditional indications for these acupoints, which are noted to be able to treat intestinal conditions. Therefore, the results were consistent with the hypothesis and also provided a possible explanation for how the use of these acupoints is able to treat intestinal conditions.

Effects of US Monetary Policy on Gross Capital Flows: Cases in Korea

  • CHOI, WOO JIN
    • KDI Journal of Economic Policy
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    • v.42 no.4
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    • pp.59-90
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    • 2020
  • U.S. monetary policy has been claimed to generate global spillover and to destabilize other small open economies. We analyze the effects of certain identified U.S. monetary shocks on gross capital flows in the Korean economy using the local projection method. Consistent with previous results on other small open economies, we initially confirm that U.S. interest rate hikes are dynamically correlated with foreign outflows and residents' inflows. That is, not only are they correlated with withdrawals by foreigners but they are also correlated with those by domestic (Korean) investors. The results are mostly driven by portfolio flows. Second, however, the marginal response to a U.S. monetary policy shock is, on average, subdued if we focus on the sample periods after the Global financial crisis of 2007-2008 (henceforth, global financial crisis). We conjecture a possible reason behind the change, an institutional change related to financial friction. If the degree of pledgeability of the value of net worth increases, the marginal responses by both investors would drop with a U.S. monetary policy shock, consistent with our findings.

Structural health monitoring response reconstruction based on UAGAN under structural condition variations with few-shot learning

  • Jun, Li;Zhengyan, He;Gao, Fan
    • Smart Structures and Systems
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    • v.30 no.6
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    • pp.687-701
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    • 2022
  • Inevitable response loss under complex operational conditions significantly affects the integrity and quality of measured data, leading the structural health monitoring (SHM) ineffective. To remedy the impact of data loss, a common way is to transfer the recorded response of available measure point to where the data loss occurred by establishing the response mapping from measured data. However, the current research has yet addressed the structural condition changes afterward and response mapping learning from a small sample. So, this paper proposes a novel data driven structural response reconstruction method based on a sophisticated designed generating adversarial network (UAGAN). Advanced deep learning techniques including U-shaped dense blocks, self-attention and a customized loss function are specialized and embedded in UAGAN to improve the universal and representative features extraction and generalized responses mapping establishment. In numerical validation, UAGAN efficiently and accurately captures the distinguished features of structural response from only 40 training samples of the intact structure. Besides, the established response mapping is universal, which effectively reconstructs responses of the structure suffered up to 10% random stiffness reduction or structural damage. In the experimental validation, UAGAN is trained with ambient response and applied to reconstruct response measured under earthquake. The reconstruction losses of response in the time and frequency domains reached 16% and 17%, that is better than the previous research, demonstrating the leading performance of the sophisticated designed network. In addition, the identified modal parameters from reconstructed and the corresponding true responses are highly consistent indicates that the proposed UAGAN is very potential to be applied to practical civil engineering.

Two distinct nodes of translational inhibition in the Integrated Stress Response

  • Ryoo, Hyung Don;Vasudevan, Deepika
    • BMB Reports
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    • v.50 no.11
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    • pp.539-545
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    • 2017
  • The Integrated Stress Response (ISR) refers to a signaling pathway initiated by stress-activated $eIF2{\alpha}$ kinases. Once activated, the pathway causes attenuation of global mRNA translation while also paradoxically inducing stress response gene expression. A detailed analysis of this pathway has helped us better understand how stressed cells coordinate gene expression at translational and transcriptional levels. The translational attenuation associated with this pathway has been largely attributed to the phosphorylation of the translational initiation factor $eIF2{\alpha}$. However, independent studies are now pointing to a second translational regulation step involving a downstream ISR target, 4E-BP, in the inhibition of eIF4E and specifically cap-dependent translation. The activation of 4E-BP is consistent with previous reports implicating the roles of 4E-BP resistant, Internal Ribosome Entry Site (IRES) dependent translation in ISR active cells. In this review, we provide an overview of the translation inhibition mechanisms engaged by the ISR and how they impact the translation of stress response genes.

Nonlinear dynamic analysis of laterally loaded pile

  • Mehndiratta, S.;Sawant, V.A.;Samadhiya, N.K.
    • Structural Engineering and Mechanics
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    • v.49 no.4
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    • pp.479-489
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    • 2014
  • In the present study a parametric analysis is conducted to study the effect of pile dimension and soil properties on the nonlinear dynamic response of pile subjected to lateral sinusoidal load at the pile head. The study is conducted on soil-pile model of different pile diameter, pile length and soil modulus, and results are compared to get the effect. The soil-pile system is modelled using Finite element method. The programming is done in MATLAB. Time history analysis of model is done for varying non-dimensional frequency of load and the results are compared to get the non-dimensional frequency at which pile head displacement is maximum in each case. Maximum possible bending moment and soil-pile interacting forces for the dynamic excitation of the pile is also compared. When results are compared with the linear response, it is observed that non-dimensional frequency is reduced in nonlinear response on account of reduction in the soil stiffness due to yielding. Nonlinear response curve shows high amplitude as compared to linear response curve.

Re-examination of Response Compatability Hypothesis in Decision-Making (결정에서 반응 조화설의 재검증)

  • Ahn, Sang-Ji;Lee, Young-Ai
    • Korean Journal of Cognitive Science
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    • v.20 no.2
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    • pp.197-223
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    • 2009
  • Three studies re-examined Shafer's(1993) response compatibility hypothesis in decision making. This hypothesis proposes that participants choose or reject an option when its features are compatible with either a selection or a rejection response. By changing the description of options into sentences and by the prior presentation of either a selection or a rejection question, we obtained results fairly consistent with the predictions of the response compatibility hypothesis. Based on the analysis of both previous and present results, we discussed the importance of preference elicitation methods when constructing options. Our results were compared to those of recent studies.

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