• Title/Summary/Keyword: Sectional model

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Tests of integrated ceilings and the construction of simulation models

  • Lyu, Zhilun;Sakaguchi, Masakazu;Saruwatari, Tomoharu;Nagano, Yasuyuki
    • Advances in Computational Design
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    • v.4 no.4
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    • pp.381-395
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    • 2019
  • This paper proposes a new approach to model the screw joints of integrated ceilings via the finite element method (FEM). The simulation models consist of the beam elements. The screw joints used in the main bars and cross bars and in the W bars and cross bars are assumed to be rotation springs. The stiffness of the rotation springs is defined according to the technical standards proposed by the National Institute for Land and Infrastructure Management of Japan. By comparing the results of the sheer tests and the simulation models, the effectiveness and efficiency of the simulation models proposed in this paper are verified. This paper indicates the possibility that the seismic performance of suspended ceilings can be confirmed directly via beam element models using FEM if the stiffnesses of the screw joints of the ceiling substrates are appropriately defined. Because cross-sectional shapes, physical properties, and other variables of the ceiling substrates can be easily changed in the models, it is expected that suspended ceiling manufactures will be able to design and confirm the seismic performance of suspended ceilings with different cross-sectional shapes or materials via computers, instead of spending large amounts of time and money on shake table tests.

A Case Study of Assessment of the Ecological Connectivity of Cross Sectional Structures in the Flowing Stream (하천 내 횡단구조물에 대한 수생태 연속성 평가 방안에 대한 연구)

  • Choi, Heung Sik
    • Ecology and Resilient Infrastructure
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    • v.7 no.4
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    • pp.320-326
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    • 2020
  • The present study aimed to assess the longitudinal connectivity owing to migrant characteristics of the target fish. The study area was Wonju-cheon Stream, and the target species were Zacco platypus and Minnows. The HEC-RAS model was used for the computation of the flow, and the ICE (Information sur la Continuite Ecologique) method was used to analyze the longitudinal connectivity. The longitudinal connectivity was assessed using the minimum overflow height, velocity, and depth of the cross sectional structure of a plunge pool and considering the swimming speed of the target fish. Simulation results indicated that the longitudinal connectivity scores for the Zacco platypus and Minnows were approximately 76 and 23, respectively.

Psychosocial Features Affecting Suicidal Ideation Among Human Immunodeficiency Virus-infected Older Adults

  • Kang, Cho Ryok;Yang, Sook Ja
    • Journal of Korean Public Health Nursing
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    • v.37 no.1
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    • pp.136-146
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    • 2023
  • This cross-sectional design study was undertaken to determine the factors associated with suicidal ideation in human immunodeficiency virus (HIV)-infected older adults. Data from a city-wide representative sample collected by the Seoul Metropolitan Government were used. The cross-sectional survey was conducted between February and March 2013. Participants selected and included in the analysis were HIV-infected adults living in Seoul, and aged 50 years and older. The overall adjusted model showed that being unemployed (adjusted odds ratio [aOR], 3.34; 95% confidence interval [CI], 1.16-9.57), a history of depression treatment (aOR, 4.61; 95% CI, 1.02-20.66), perceived belongingness (aOR, 0.63; 95% CI, 0.41-0.99), and psychological functioning (aOR, 0.85; 95% CI, 0.73-0.99) were significantly related to suicidal ideation. Psychosocial features were found to be strongly associated with suicidal ideation among HIV-infected older adults. The findings could be useful for HIV nursing consultants to identify HIV-infected older adults who are vulnerable to suicidal ideation. Comprehensive mental health services should be provided as coping resources for HIV-infected older adults who have suicidal ideation.

A Study on the Determinants of Free Trade Agreement in South Korea: Evidence from Asian Countries

  • He, Yugang
    • Journal of Distribution Science
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    • v.16 no.11
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    • pp.37-45
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    • 2018
  • Purpose - Recently, large quantities of factors have affected the signing of the Free Trade Agreement between two countries. Due to this background, this paper selects South Korea as an example to explore the determinants of Free Trade Agreement from Asian countries. Research design, data, and methodology - A cross sectional data of 2016 will be employed and some variables such as real income and GDP will be used to run an empirical analysis under the linear probability model, probit model and logit model. Results - The findings show that the Asian countries' exchange rate regime, real income, GDP and so forth can increase the probability of signing the Free Trade Agreement with Asian countries. Conversely, the distance can lower the probability of signing the Free Trade Agreement with Asian countries. Meanwhile, although the Asian countries' import, consumer price index and population also can affect the probability of signing the Free Trade Agreement with Asian countries, the estimated coefficients are not statistically significant at 5% level. Conclusions - According to the empirical results, this paper provides a new scope for South Korea's government to sign the Free Trade Agreement with other Asian countries.

Hybrid Two-Dimensional Finite Element Model of Tires (타이어의 복합 이차원 유한 요소 모델)

  • Kim, Yong-Joe;Bolton, J.Stuart
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.62-67
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    • 2002
  • It has been shown that the vibrational response of a tire can be represented by a set of decaying waves, each associated with a particular cross-sectional mode shape in the region near the contact patch. Thus, it can be concluded that tires can be effectively modeled as lossy waveguides. It has also been shown that the sound radiation from tires is mainly from the region close to the contact patch. In consequence, it may be computationally efficient to analyze tire vibration and sound radiation in the region close to the contact patch by using a hybrid finite element model in which the cross-section of a tire is approximated by 2-D finite elements while an analytical wave solution is assumed in the circumferential direction of the tire. In this article. a hybrid finite element was formulated based on a composite shell model. The dispersion relations for sample structures obtained by using the hybrid FE model were then compared with those obtained by using a full, three-dimensional FE model. It has been shown that the FE analysis made using the hybrid 2-D finite elements yields results in close agreement with the three-dimensional model.

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Geometry of the Model Purse Seine in Relation to Enclosed Volume during Hauling Operation

  • Kim Yong-Hae
    • Fisheries and Aquatic Sciences
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    • v.3 no.2
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    • pp.156-162
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    • 2000
  • Model experiments for a purse seine were carried out in order to measure the geometry of net shape and to estimate an enclosed volume by using 1177 scale model purse seine of 12.62m float line from an offshore mackerel purse seine. A model purse seine was set from a net box of shooting equipments and then pursing and hauling net by hauling equipment. The 3- D geometry shape of the purse seine net during hauling operation was measured by video image processing and tension of purse line by load cell. The 3-D geometry of the model purse seine during hauling operation could be represented with variables such as a ratio of shooting diameter or maximum net depth and a ratio of hauling operation time. Horizontal shapes of float line and lead line were varied from a circle after shooting to an ellipse with pursing and hauling. Projected lateral shape of purse line was observed and formulated as a shape of a water drop. The cross sectional shapes of curved net from two directions were varied such as sine function or polynomial curves. Therefore, enclosed volume of a purse seine in relation to fish school behaviour can be approximated using two main variables from relevant equations.

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The effects of Personality Trait and Social Cognitive Factors on Knowledge Sharing Behavior of the Hospital Nurses (성격적 특성과 사회인지적 요인이 병원 근무 간호사의 지식공유행동에 미치는 영향)

  • Youn, Kyung-Il;Lee, Won-Jae
    • Korea Journal of Hospital Management
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    • v.11 no.4
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    • pp.37-62
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    • 2006
  • This study investigates the antecedents of knowledge sharing behavior focusing on the individual level factors in an assumption that the behavior is initiated from the individual level decisions. A hypothesis that the relation between personality trait and behavior is mediated by the social-cognitive constructs contained in the Theory of Planned Behavior(TPB) is tested. For the study, we suggest a TPB extended model that extends original TPB model by including conscientiousness facet of FFM(Five Factor Model). This study uses a cross-sectional design. Data were collected from a self-reported survey on 197 nurses in a tertiary hospital. The results showes a significant positive relationship between the conscientiousness facet of FFM and knowledge sharing behavior. In the TPB extended model, the conscientiousness facet has significant direct effects on all the constructs of original TPB model. Of the TPB exogenous constructs, the social norm construct alone has a significant effect on intention and the perceived behavioral has a direct significant effect on the knowledge sharing behavior. These results confirm the importance of conscientiousness in predicting knowledge sharing behavior and clarify the characteristics of knowledge sharing behavior as a contextual, job oriented behavior in a workplace. We conclude that personality trait as conceptualized in the FFM needs to be integrated into TPB model in explaining the knowledge sharing behavior. Based on these results theoretical and practical implications are discussed.

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Effects of joint aspect ratio on required transverse reinforcement of exterior joints subjected to cyclic loading

  • Chun, Sung Chul
    • Earthquakes and Structures
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    • v.7 no.5
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    • pp.705-718
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    • 2014
  • This paper presents an analytical model for determining the transverse reinforcement required for reinforced concrete exterior beam-column joints subjected to reversed cyclic loading. Although the joint aspect ratio can affect joint shear strength, current design codes do not consider its effects in calculating joint shear strength and the necessary amount of transverse reinforcement. This study re-evaluated previous exterior beam-column joint tests collected from 11 references and showed that the joint shear strength decreases as the joint aspect ratio increases. An analytical model was developed, to quantify the transverse reinforcement required to secure safe load flows in exterior beam-column joints. Comparisons with a database of exterior beam-column joint tests from published literature validated the model. The required sectional ratios of horizontal transverse reinforcement calculated by the proposed model were compared with those specified in ACI 352R-02. More transverse reinforcement is required as the joint aspect ratio increases, or as the ratio of vertical reinforcement decreases; however, ACI 352R-02 specifies a constant transverse reinforcement, regardless of the joint aspect ratio. This reevaluation of test data and the results of the analytical model demonstrate a need for new criteria that take the effects of joint aspect ratio into account in exterior joint design.

Shear strength evaluation of RC solid piers of high-speed railway bridges in China

  • Guo, Wei;Fan, Chao;Cui, Yao;Zeng, Chen;Jiang, Lizhong;Yu, Zhiwu
    • Structural Engineering and Mechanics
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    • v.78 no.4
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    • pp.413-423
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    • 2021
  • Piers are the main lateral force-resisting members of high-speed railway (HSR) bridges used in China and are characterized by low axial load ratios, low longitudinal reinforcement ratios, low stirrup ratios, and high shear span ratios. It is well known that flexural, flexural-shear, and shear failures of piers may occur during an earthquake. In this study, a new shear strength model was developed to simulate the seismic failure of HSR solid piers accurately. First, low cyclic-loading test data of solid piers obtained in recent years were collected to set up a database for model verification. Second, based on the test database, the applicability of existing shear strength models was evaluated. Finally, a new shear strength model for HSR solid piers with round-ended cross-sections was derived based on the truss model and ultimate equilibrium theory. In comparison with existing models, it was demonstrated that the proposed model could be used to predict the shear strength of HSR piers more accurately.

Investigation of Demand-Control-Support Model and Effort-Reward Imbalance Model as Predictor of Counterproductive Work Behaviors

  • Mohammad Babamiri;Bahareh Heydari;Alireza Mortezapour;Tahmineh M. Tamadon
    • Safety and Health at Work
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    • v.13 no.4
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    • pp.469-474
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    • 2022
  • Background: Nowadays, counter-productive work behaviors (CWBs) have turned into a common and costly position for many organizations and especially health centers. Therefore, the study was carried out to examine and compare the demand-control-support (DCS) and effort-reward imbalance (ERI) models as predictors of CWBs. Methods: The study was cross-sectional. The population was all nurses working in public hospitals in Hamadan, Iran of whom 320 were selected as the sample based on simple random sampling method. The instruments used were Job Content Questionnaire, Effort-Reward Imbalance Questionnaire, and Counterproductivity Work Behavior Questionnaire. Data were analyzed using correlation and regression analysis in SPSS18. Results: The findings indicated that both ERI and DCS models could predict CWB (p ≤ 0.05); however, the DCS model variables can explain the variance of CWB-I and CWB-O approximately 8% more than the ERI model variables and have more power in predicting these behaviors in the nursing community. Conclusion: According to the results, job stress is a key factor in the incidence of CWBs among nurses. Considering the importance and impact of each component of ERI and DCS models in the occurrence of CWBs, corrective actions can be taken to reduce their incidence in nurses.