• Title/Summary/Keyword: capacity analysis

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Propose of Capacity Spectrum Method by Nonlinear Earthquake Response Analysis (질점계 비선형 지진응답해석에 의한 구조물의 역량스펙트럼 제안)

  • You, Jin-Sun;Yang, Won-Jik;Yi, Waon-Ho;Kim, Hyoung-Joon
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.27 no.6
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    • pp.501-508
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    • 2014
  • In this paper, a method on deducing the capacity spectrum based on nonlinear earthquake response analysis will be introduced. Damage assessment of general building draws the capacity spectrum through the Push-over analysis and the intersection point of capacity spectrum and demand spectrum is seen as performance point. Push-over analysis is the way to perform static analysis by using the equivalent static load changed from the effect of earthquake and predict the behavior of structures by earthquake. But, this method can not be taken into account in the effects of higher mode and the dynamic characteristic. Therefore, in order to calculate the capacity spectrum under dynamic properties of building. A capacity spectrum from going ahead with the nonlinear earthquake response analysis is suggested.

Studies on T-Shaped composite columns consist of multi separate concrete-filled square tubular steel sections under eccentric axial load

  • Rong, Bin;You, Guangchao;Zhang, Ruoyu;Feng, Changxi;Liu, Rui
    • Steel and Composite Structures
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    • v.22 no.2
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    • pp.217-234
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    • 2016
  • In order to investigate mechanical properties and load-bearing capacity of T-shaped Concrete-Filled Square Steel Tubular (TCFST) composite columns under eccentric axial load, three T-shaped composite columns were tested under eccentric compression. Experimental results show that failure mode of the columns under eccentric compression was bending buckling of the whole specimen, and mono column performs flexural buckling. Specimens behaved good ductility and load-bearing capacity. Nonlinear finite element analysis was also employed in this investigation. The failure mode, the load-displacement curve and the ultimate bearing capacity of the finite element analysis are in good agreement with the experimental ones. Based on eccentric compression test and parametric finite element analysis, the calculation formula for the equivalent slenderness ratio was proposed and the bearing capacity of TCFST composite columns under eccentric compression was calculated. Results of theoretical calculation, parametric finite element analysis and eccentric compression experiment accord well with each other, which indicates that the theoretical calculation method of the bearing capacity is advisable.

Improvement of tip analysis model for drilled shafts in cohesionless soils

  • Chen, Yit-Jin;Wu, Hao-Wei;Marcos, Maria Cecilia M.;Lin, Shiu-Shin
    • Geomechanics and Engineering
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    • v.5 no.5
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    • pp.447-462
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    • 2013
  • An analysis model for predicting the tip bearing capacity of drilled shafts in cohesionless soils is improved in this study. The evaluation is based on large amounts of drilled shaft load test data. Assessment on the analysis model reveals a greater variation in two coefficients, namely, the overburden bearing capacity factor ($N_q$) and the bearing capacity modifier for soil rigidity (${\zeta}_{qr}$). These factors are modified from the back analysis of drilled shaft load test results. Different effective shaft depths and interpreted capacities at various loading stages (i.e., low, middle, and high) are adopted for the back calculation. Results show that the modified bearing capacity coefficients maintain their basic relationship with soil effective friction angle ($\bar{\phi}$), in which the $N_q$ increases and ${\zeta}_{qr}$ decreases as $\bar{\phi}$ increases. The suggested effective shaft depth is limited to 15B (B = shaft diameter) for the evaluation of effective overburden pressure. Specific design recommendations for the tip bearing capacity analysis of drilled shafts in cohesionless soils are given for engineering practice.

Influence of Internal and External Capacity on Adults' Food Waste Disposal Capacity (내적역량과 외적역량이 성인의 식품 쓰레기 처분에 대한 실천역량에 미치는 영향)

  • Kim, Ji Eun;Choi, Kyoung Sook
    • Korean Journal of Community Nutrition
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    • v.26 no.6
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    • pp.455-466
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    • 2021
  • Objectives: The purpose of this study was to investigate the effects of internal and external capacity on the practical capacity for food waste disposal in adults. Methods: The study subjects were 410 adults who answered a structured questionnaire. The survey was conducted in January 2021. Data were analyzed through descriprive analysis, t-test, ANOVA, and multiple regression analysis using the SPSS Win 24.0. Results: First, in the analysis of internal capacity, attitude (3.95 out of 5 points) scored higher than knowledge (3.59 points). Attitudes showed significant differences according to gender (P < 0.001), age (P < 0.001), and income (P < 0.001). Knowledge showed significant differences according to gender (P < 0.01) and age (P < 0.05). Second, in the analysis of capacity, market constraints (3.73 points) scored the highest, followed by institutional conditions (3.48 points) and reference group (3.36 points). Market constraints differed according to gender (P < 0.001), and institutional conditions differed according to income (P < 0.001). There was a significant difference in the reference group according to the level of education (P < 0.05) and income (P < 0.05). Third, the practical capacity scores appeared in the order of separating discharge behavior, using behavior, purchasing behavior, and leadership behavior. Separating discharge behavior showed significant differences according to gender (P < 0.001), education level (P < 0.05), and income (P < 0.01). Using behavior showed a difference according to gender (P < 0.01), and purchasing behavior showed a significant difference according to income (P < 0.05). Leadership behavior showed no difference according to demographic factors. Fourth, internal capacity and external capacity showed a significant positive relationship with practical capacity. Factors affecting purchasing behavior were knowledge, attitude, institutional conditions, and reference group, and their explanatory power was 53%. Factors influencing using behavior were knowledge, attitude, institutional conditions, and reference group, and had an explanatory power of 37%. Leadership behavior was influenced by institutional conditions and the reference group, with an explanatory power of 31%. Conclusions: Internal capacity, external capacity, and practical capacity show differences according to demographic factors. Factors influencing the practical capacity of adults were knowledge, attitude, institutional conditions, and reference group.

Development of New Freeway Capacity Estimation Method (고속도로의 용량산정 방법론 개발에 관한 연구)

  • Kim, Young Sun;Lee, Sang Soo
    • International Journal of Highway Engineering
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    • v.17 no.5
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    • pp.123-133
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    • 2015
  • PURPOSES : This study aimed to develop a new highway capacity estimation method and provide comparative results among traditional capacity estimation methods and the recommended values in the latest version of KHCM. METHODS : The limitations of the existing methods, such as inconsistency and underestimation of the capacity value, are summarized through an extensive literature review. To overcome these limitations, a new method is introduced by adopting a definition of capacity and traffic flow characteristics at or near breakdown points. This method can produce the capacity value by searching a point corresponding to the maximum traffic flow through analysis of gradient changes (point of inflection) of the traffic flow and speed distribution. Comparative results of capacity values from each method are also presented to validate the new method by using data collected from detectors on freeways. RESULTS: From the analysis results, it is shown that a consistent capacity value can be estimated by applying the new method. In addition, the resulting capacity values are 3%-4% higher than those recommended in KHCM. CONCLUSIONS : The capacity values listed in the current KHCM tend to produce underestimated results. The new method presented in this paper may be included in the future edition of KHCM.

Analysis of Load-Settlement Curves in Driven and Embedded Piles (항타 및 매입말뚝의 하중-침하량 곡선의 분석)

  • 천병식;조천환
    • Geotechnical Engineering
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    • v.13 no.6
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    • pp.61-70
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    • 1997
  • Although the load -settlement curve characteristics of embedded piles are different from those of driven piles, for the determination of their allowable loads the same analysis method has been adopted without any considerations. According to the related domestic chi teria, the analysis methods of load-settlement curve have some conflicts among themselves and have several vague points in obtaining the allowable capacity from ultimate or yield capacity. In order to solve those problems, the relevant literatures were reviewed. And also the result of 106 pile load tests was analysed. Analysis result indicates that analysis met hods of the load-settlement curve based on single mathematical curve are not suitable for the general analysis method of load-settlement curves due to their various characteristics. As a result, the appropriate analysis methods and safety factors for the determination of allowable capacity of pile are suggested in this paper.

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Effects of Treadmill Exercise on Pulmonary Function and Gait Capacity in Stroke Patients : A meta-analysis (트레드밀 운동이 뇌졸중 환자의 폐기능과 보행능력에 미치는 효과 : 메타분석)

  • Cho, Sunghyoun;Choi, Kibok
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.2
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    • pp.169-185
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    • 2020
  • Purpose : This study aimed to conduct a comprehensive meta-analysis to evaluate the effect size for pulmonary function and gait capacity of treadmill exercise in stroke patients. In addition, we aimed to examine the current status of treadmill interventions and compare the effect sizes of treadmill training to provide evidence-based practice for future development and application. Methods : The meta-analysis study was conducted using research articles that applied treadmill exercise to stroke patients and were published between January 2005 and February 2020. For a systematic meta-analysis, we conducted a search using the PICOS framework and selected 25 domestic stroke- and treadmill-related studies. The Comprehensive Meta-Analysis program was used to calculate the effect sizes for lung function and gait capacity (6-minute walk test and 10 m walk test). As Cohen's d has a tendency to overestimate the effect size, we used Hedge's g to increase the accuracy in computing the effect size. Results : Based on the results of the meta-analysis, the total effect size of treadmill exercise was 0.535, which was statistically significant, with a medium effect size (p<0.05). The effects of treadmill exercise in stroke patients were divided into dependent variables, namely pulmonary function (0.372) and gait capacity (0.584). In addition, for gait capacity, the effect sizes were evaluated for both the 6-minute walk test (0.756) and the 10 m walk test (0.514). Conclusion : This study provides objective evidence of the effectiveness of treadmill-based gait training programs. We hope that the results of this study will help support the development and implementation of treadmill-based gait training in stroke patients. Treadmill training is expected to improve not only pulmonary function, but also the gait capacity of stroke patients. Long-term investigations on the effects of treadmill training in stroke patients are necessary.

Estimation of Plastic Energy Dissipation Amount of Multi-bent Spatial structure by Equivalent Linear Analysis

  • Lee, Seung-Jae
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.2 s.20
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    • pp.131-136
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    • 2006
  • It is important to evaluate energy absorption capacity of frames required during a design earthquake. An inelastic computer analysis based on mathematical modelling of energy absorbing frames and elements makes it possible to evaluate required energy absorption capacity. But such an analysis sometimes consumes much computation time particularly in case of complicated structural system. This paper presents a proposal to predict energy absorption of multi-bent steel frames by simple equivalent linear method.

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Development of Disaster Management Capacity Analysis Program for Local Government (지방자치단체 재난안전관리 자체 역량분석 프로그램 개발)

  • Yoo, Byungtae;Oh, Keumho
    • Journal of the Society of Disaster Information
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    • v.9 no.3
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    • pp.266-275
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    • 2013
  • New paradigm to the advancement of disaster management is required for building resilient and safe society. In these circumstances, the importance of local government disaster management capacity has been emphasized through experiencing a series of accidents including 2012 september Gumi fluorosilicic acid diffusion accident. The increase of people's disaster awareness has emerged the public demands on disaster management information of local area. In this study, the disaster management capacity analysis program is developed for self-assessment of local government. The program is designed for disaster managers to database the categorized index of disaster management capacity and recognize the capacity level. For the public announcement of disaster management capacity, the analysis results are shown for citizens in the understandable format. It is expected that the enhancement of emergency management capacity of local society can be achieved by the efforts of local government analyzing and improving the vulnerability as well as the participation of local society.

Seismic Performance Evaluation of Building Structures Using Modified Capacity Spectrum (수정된 능력스펙트럼을 이용한 건축구조물의 내진성능평가)

  • 최원호
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2000.04a
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    • pp.267-274
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    • 2000
  • Current seismic design codes for building structures are based on the method which can provide enough capacity to satisfy objected performance level and exactly evaluate the seismic performance of buildings. The capacity spectrum method using the nonlinear static(pushover) analysis is becoming a popular tool for evaluating the seismic performance of existing and new building structures. By means of a graphical procedure capacity spectrum method esimates the performance level of structure by comparing the capacity of structure with the demand of earthquake ground motion on the structure. In the method the relation between base shear estimated by a nonlinear static analysis and horizontal displacement is used. Capacity spectrum is usually expressed as what represent the responses of the equivalent single degree of freedom (ESDOF) system for the building structures. However there are some problems in converting procedures into ESDOF system which include not considering the effect of higher modes of structures. The objective of this paper is to compare and verify existing methods and suggest the modified capacity spectrum for seismic performance evaluation of building structures.

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