• Title/Summary/Keyword: response analysis

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A new non-iterative procedure to estimate seismic demands of structures

  • Mechaala, Abdelmounaim;Chikh, Benazouz
    • Earthquakes and Structures
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    • v.22 no.6
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    • pp.585-595
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    • 2022
  • Using the nonlinear static procedures has become very common in seismic codes to achieve the nonlinear response of the structure during an earthquake. The capacity spectrum method (CSM) adopted in ATC-40 is considered as one of the most known and useful procedures. For this procedure the seismic demand can be approximated from the maximum deformation of an equivalent linear elastic Single-Degree-of-Freedom system (SDOF) that has an equivalent damping ratio and period by using an iterative procedure. Data from the results of this procedure are plotted in acceleration- displacement response spectrum (ADRS) format. Different improvements have been made in order to have more accurate results compared to the Non Linear Time History Analysis (NL-THA). A new procedure is presented in this paper where the iteration process shall not be required. This will be done by estimation the ductility demand response spectrum (DDRS) and the corresponding effective damping of the bilinear system based on a new parameter of control, called normalized yield strength coefficient (η), while retaining the attraction of graphical implementation of the improved procedure of the FEMA-440. The proposed procedure accuracy should be verified with the NL-THA analysis results as a first implementation. The comparison shows that the new procedure provided a good estimation of the nonlinear response of the structure compared with those obtained when using the NL-THA analysis.

A Study on Response Analysis by Transmission Error of Yaw Drive for 8 MW Large Capacity Wind Turbines (8 MW급 대용량 풍력발전기용 요 감속기 치합전달오차에 따른 응답해석에 관한 연구)

  • Seo-Won Jang;Se-Ho Park;Young-kuk Kim;Min-Woo Kim;Hyoung-Woo Lee
    • Journal of Wind Energy
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    • v.15 no.1
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    • pp.43-49
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    • 2024
  • This study performed a response analysis according to the transmission error of the yaw drive. To perform the response analysis, the excitation source of the transmission error was modeled and the outer ring of the first stage bearing and the outer ring of the output shaft bearing were used as measurement positions. The response results were analyzed based on the vibration tolerance values of AGMA 6000-B96. As a result of the response of the first stage bearing outer ring, the maximum displacement of the first stage planetary gear system was 5.59 and the maximum displacement of the second to fourth stage planetary gear systems was 4.21 ㎛ , 3.13 ㎛ , and 25.6 ㎛ . In the case of the output shaft bearing outer ring, the maximum displacement of the first stage planetary gear system was 1.73 ㎛, and the maximum displacement of the second to fourth stage planetary gear system was 1.94 ㎛, 0.73 ㎛, and 2.03 ㎛. According to AGMA 6000-B96, the vibration tolerance of first stage is 17.5 ㎛, and the vibration tolerance of the second to fourth stages is 58 ㎛, 80 ㎛, and 375 ㎛, which shows that the vibration tolerance is satisfied and it is safe.

Developing Product Liability Response Strategies of SMEs using PEST-SWOT-AHP analysis (PEST-SWOT-AHP 분석을 이용한 중소제조기업의 제조물책임 대응전략 수립)

  • Seo, JunHyeok;Bae, SungMin
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.39 no.2
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    • pp.11-18
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    • 2016
  • Product liability (PL), which began enforcement in 2002, refers to the legal responsibility of the manufacturers or sellers (wholesales or retailers) for the property damage or bodily harm caused by their product. With a strong enforcement of the Product Liability (PL) Act, companies are required to structure and operate a response system to defend or prevent product accidents efficiently, but small and medium enterprises (SMEs) are unable to respond more aggressively due to limitation of management resources. In this manner, it is important to develop response strategies for SMEs to efficiently cope with the PL Act. In this paper, the PEST (Political, Economic, Social, and Technological) analysis is performed to reveal the impact of the PL Act on SMEs in macro-economic point of view. To formulate SME's PL response strategy, SWOT analysis is performed to categorize each factors from PEST analysis and AHP is applied to identify the intensities of SWOT factors. The prioritized SWOT factor, results of PEST-SWOT-AHP analysis, are used to formulate SME's PL response strategies. The study results are briefly summarized as follows. To reduce product defects, it is necessary for SMEs to formulate PL response strategies for each phase of the product life cycle by continuously collecting and analyzing PL cases in the same industry or for similar products. In addition, SMEs should invest more technological effort to ensure product safety. Further, SMEs should spread PL awareness to all staff members by training internal PL experts. Moreover, a SME should enroll in PL insurance and spread this information to its customers so that they become aware that the company is proactively conforming to the PL law.

A Study on Sentiment Analysis of Media and SNS response to National Policy: focusing on policy of Child allowance, Childbirth grant (국가 정책에 대한 언론과 SNS 반응의 감성 분석 연구 -아동 수당, 출산 장려금 정책을 중심으로-)

  • Yun, Hye Min;Choi, Eun Jung
    • Journal of Digital Convergence
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    • v.17 no.2
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    • pp.195-200
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    • 2019
  • Nowadays as the use of mobile communication devices such as smart phones and tablets and the use of Computer is expanded, data is being collected exponentially on the Internet. In addition, due to the development of SNS, users can freely communicate with each other and share information in various fields, so various opinions are accumulated in the from of big data. Accordingly, big data analysis techniques are being used to find out the difference between the response of the general public and the response of the media. In this paper, we analyzed the public response in SNS about child allowance and childbirth grant and analyzed the response of the media. Therefore we gathered articles and comments of users which were posted on Twitter for a certain period of time and crawling the news articles and applied sentiment analysis. From these data, we compared the opinion of the public posted on SNS with the response of the media expressed in news articles. As a result, we found that there is a different response to some national policy between the public and the media.

Seismic Response on Thin Shell as Structural Foundation (기초구조물로서 얇은 쉘 구조물의 지진응답)

  • Yee Hooi Min;Azizah Abdul Nassir;Kim Jae Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.24 no.2
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    • pp.31-41
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    • 2024
  • This study aims to investigate the seismic response of a large span thin shell structures and assess their displacement under seismic loads. The study employs finite element analysis to model a thin shell structure subjected to seismic excitation. The analysis includes eigenvalue analysis and time history analysis to evaluate the natural frequencies and displacement response of the structure under seismic loads. The findings show that the seismic response of the large span thin shell structure is highly dependent on the frequency content of the seismic excitation. The eigenvalue analysis reveals that the tenth mode of vibration of the structure corresponds to a large-span mode. The time history analysis further demonstrates, with 5% damping, that the displacement response of the structure at the critical node number 4920 increases with increasing seismic intensity, reaching a maximum displacement of 49.87mm at 3.615 seconds. Nevertheless, the maximum displacement is well below the allowable limit of the thin shell. The results of this study provide insight into the behaviour of complex large span thin shell structures as elevated foundations for buildings under seismic excitation, based on the displacement contours on different modes of eigenvalues. The findings suggest that the displacement response of the structure is significant for this new application of thin shell, and it is recommended to enhance the critical displacement area in the next design phase to align with the findings of this study to resist the seismic impact.

Prognostic Factors for Second-line Treatment of Advanced Non-small-cell Lung Cancer: Retrospective Analysis at a Single Institution

  • Inal, Ali;Kaplan, M. Ali;Kucukoner, Mehmet;Urakci, Zuhat;Karakus, Abdullah;Isikdogan, Abdurrahman
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.4
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    • pp.1281-1284
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    • 2012
  • Background: Platinum-hased chemotherapy for advanced non-small cell lung cancer (NSCLC) is still considered the first choice, presenting a modest survival advantage. However, the patients eventually experience disease progression and require second-line therapy. While there are reliable predictors to identify patients receiving first-line chemotherapy, very little knowledge is available about the prognostic factors in patients who receive second-line treatments. The present study was therefore performed. Methods: We retrospectively reviewed 107 patients receiving second-line treatments from August 2002 to March 2012 in the Dicle University, School of Medicine, Department of Medical Oncology. Fourteen potential prognostic variables were chosen for analysis in this study. Univariate and multivariate analyses were conducted to identify prognostic factors associated with survival. Result: The results of univariate analysis for overall survival (OS) were identified to have prognostic significance: performance status (PS), stage, response to first-line chemotherapy response to second-line chemotherapy and number of metastasis. PS, diabetes mellitus (DM), response to first-line chemotherapy and response to second-line chemotherapy were identified to have prognostic significance for progression-free survival (PFS). Multivariate analysis showed that PS, response to first-line chemotherapy and response to second-line chemotherapy were considered independent prognostic factors for OS. Furthermore, PS and response to second-line chemotherapy were considered independent prognostic factors for PFS. Conclusion: In conclusion, PS, response to first and second-line chemotherapy were identified as important prognostic factors for OS in advanced NSCLC patients who were undergoing second-line palliative treatment. Furthermore, PS and response to second-line chemotherapy were considered independent prognostic factors for PFS. It may be concluded that these findings may facilitate pretreatment prediction of survival and can be used for selecting patients for the correct choice of treatment.

ABCG2 C421A Polymorphism and Imatinib Response in Chronic Myeloid Leukemia: A Systematic Review and Meta-Analysis (ABCG2 C421A 다형성이 만성 골수성 백혈병 환자의 imatinib 치료에 미치는 영향: 체계적 문헌고찰 및 메타분석)

  • Oh, Da Hyun;Chun, Pusoon
    • Korean Journal of Clinical Pharmacy
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    • v.26 no.1
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    • pp.53-58
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    • 2016
  • Objective: To estimate the association between ABCG2 C421A polymorphism and response to imatinib in chronic myeloid leukemia. Methods: A systematic review was conducted to evaluate the effect of ABCG2 C421A polymorphism on imatinib response. The databases of PubMed, Embase, Web of science, CINAHL with FullText, and Cochrane Library were searched for all published studies from inception to December 2015. The following terms were used with functions of 'AND' and 'OR': 'chronic myeloid leukemia', 'CML', 'drug transporter', 'ABCG2', 'BCRP', 'polymorphisms', 'SNPs', and 'imatinib'. The studies reporting the association between ABCG2 polymorphism and imatinib response were evaluated. Results: A total of 7 studies were included in the present meta-analysis. The pooled analysis showed that ABCG2 c.421CC genotype was significantly associated with poor response to imatinib under the dominant model (CC vs CA+AA; OR: 0.56; 95% CI: 0.41, 0.77; p = 0.0004). The subgroup analysis of Asian studies demonstrated a significantly lower response in c.421CC genotype than in c.421CA or c.421AA genotype (OR: 0.52; 95% CI: 0.37, 0.73; p = 0.0002). In subgroup analyses of 5 studies, the patients with the c.421CC genotype exhibited higher risk for worse response than the patients with c.421CA or c.421AA genotype (heterozygote codominant model: CC vs. AC; OR: 0.49, 95% CI: 0.33, 0.73; p = 0.0006; homozygote codominant model: CC vs AA; OR: 0.43; 95% CI: 0.25, 0.75, p = 0.003). Conclusion: The ABCG2 c.421CC genotype was significantly associated with poor response to imatinib compared to the c.421CA and c.421AA genotypes in chronic myeloid leukemia, especially in Asian patients.

Application of Effective Earthquake Force by the Boundary Reaction Method and a PML for Nonlinear Time-Domain Soil-Structure Interaction Analysis of a Standard Nuclear Power Plant Structure (원전구조물의 비선형 시간영역 SSI 해석을 위한 경계반력법에 의한 유효지진하중과 PML의 적용)

  • Lee, Hyeok Ju;Lim, Jae Sung;Moon, Il Hwan;Kim, Jae Min
    • Journal of the Earthquake Engineering Society of Korea
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    • v.27 no.1
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    • pp.25-35
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    • 2023
  • Considering the non-linear behavior of structure and soil when evaluating a nuclear power plant's seismic safety under a beyond-design basis earthquake is essential. In order to obtain the nonlinear response of a nuclear power plant structure, a time-domain SSI analysis method that considers the nonlinearity of soil and structure and the nonlinear Soil-Structure Interaction (SSI) effect is necessary. The Boundary Reaction Method (BRM) is a time-domain SSI analysis method. The BRM can be applied effectively with a Perfectly Matched Layer (PML), which is an effective energy absorbing boundary condition. The BRM has a characteristic that the magnitude of the response in far-field soil increases as the boundary interface of the effective seismic load moves outward. In addition, the PML has poor absorption performance of low-frequency waves. For this reason, the accuracy of the low-frequency response may be degraded when analyzing the combination of the BRM and the PML. In this study, the accuracy of the analysis response was improved by adjusting the PML input parameters to improve this problem. The accuracy of the response was evaluated by using the analysis response using KIESSI-3D, a frequency domain SSI analysis program, as a reference solution. As a result of the analysis applying the optimal PML parameter, the average error rate of the acceleration response spectrum for 9 degrees of freedom of the structure was 3.40%, which was highly similar to the reference result. In addition, time-domain nonlinear SSI analysis was performed with the soil's nonlinearity to show this study's applicability. As a result of nonlinear SSI analysis, plastic deformation was concentrated in the soil around the foundation. The analysis results found that the analysis method combining BRM and PML can be effectively applied to the seismic response analysis of nuclear power plant structures.

Aerostatic and buffeting response characteristics of catwalk in a long-span suspension bridge

  • Li, Yongle;Wang, Dongxu;Wu, Chupeng;Chen, Xinzhong
    • Wind and Structures
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    • v.19 no.6
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    • pp.665-686
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    • 2014
  • This study presents a comprehensive investigation of the aerostatic and buffeting response characteristics of a suspension bridge catwalk. The three-dimensional aerostatic response analysis was carried out taking into account the geometric nonlinearity and nonlinear dependence of wind loads on the angle of attack. The buffeting response analysis was performed in the time domain. The aerostatic and buffeting responses of the catwalk show strong coupling of vertical and lateral vibrations. The lateral displacement is the main component of the wind-induced static and buffeting response of the catwalk.

Design of Frictional Bearing in Isolated Bridge Using Nonlinear Response Spectrum (비선형 응답스펙트럼을 이용한 지진격리교량의 마찰받침 설계)

  • 하동호;송현섭;고현무
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2001.09a
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    • pp.311-319
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    • 2001
  • Recently, the number of seismically isolated bridges increased suddenly since the occurrence of strong earthquakes. However, because isolator lies between pier and girder, the response of the superstructure of seismically isolated bridge may be magnified and induce risk of unseating girder Consequently, the response of girder constitutes a crucial factor in designing bridge. In the case of frictional bearing, the inherent nonlinearity makes the use of former linear response spectrum unable to estimate the maximum response of the bearing, and nonlinear tlme history analysis shall be applied. In this paper, nonlinear response spectrum considering frictional element is established, and simple analysis method using such nonlinear spectrum is proposed to estimate the maximum response of the superstructure.

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