• Title/Summary/Keyword: distress model

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Finite element investigation of the joints in precast concrete pavement

  • Sadeghi, Vahid;Hesami, Saeid
    • Computers and Concrete
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    • v.21 no.5
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    • pp.547-557
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    • 2018
  • This paper measures the mechanical response of precast pavement joints under moving axle loads using the finite-element method, and the models were validated with results of field tests. In order to increase the ability to use the non-linear FE analysis for design and assessment of precast pavement subjected to moving axle load, this paper investigated the effects of different load transfer between the slabs using the ABAQUS finite-element package to solve the nonlinear explicit model equations. The assembly of the panels using dowels and groove-tongue keys has been studied to assess the efficiency of keyway joint system. Concrete damage plasticity model was used to calculate the effects of permanent damages related to the failure mechanisms. With aggregate interlock as the only load transferring system, Load transfer efficiency (LTE) is not acceptable when the axle load reaches to slab joints. The Finite-element modelling (FEM) results showed that keyway joints significantly reduced tensile stresses developed at the mid-slab. Increasing the thickness of the tongue the LTE was improved but with increasing the height of the tongue the LTE was decreased. Stresses are transferred to the adjacent slab efficiently when dowels are embedded within the model. When the axle load approaches joints, tensile damage occurs sooner than compressive damage, but the damage rate remains constant, then compressive damage increases significantly and become the major form of distress under the dowels.

Construction of an Explanatory Model of Female Sexual Dysfunction (여성 성기능장애의 예측 모형)

  • Bae, Jeong-Yee;Min, Kweon-Sik;Ahn, Suk-Hee
    • Journal of Korean Academy of Nursing
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    • v.37 no.7
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    • pp.1080-1090
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    • 2007
  • Purpose: Although concerns of female sexual dysfunction (FSD) are increasing in Korea, sexual dysfunction related factors are limited in research studies. The aim of this study was to develop an explanatory model that will further explain the continuously increasing female sexual dysfunction cases in Korea. Methods: Survey visits were conducted to four hundred and eighty five women, over 25 years of age and presently residing in either urban or rural areas. All of them were analyzed using a structured questionnaire. A total of 8 instruments were used in this model. The analysis of data was done with both SPSS WIN for descriptive statistics and AMOS 5.0 for covariance structure analysis. Results: As a result, variables that showed notably direct effects on FSD were: sexual concept (sexual attitude), sexual distress, and psychosocial health (depression, crisis, traumatic life events). On the other hand, variables such as age, educational level, economic status, and marital status showed indirect influences on health-promoting behaviors. Conclusion: By comprehensively addressing the factors related to sexual dysfunction, and comparing each influence, this study can contribute to designing an appropriate sexual dysfunction prevention strategy in tune with the particular characteristics and problems of a client.

The Study on the Risk Predict Method and Government Funds Supporting for Small and Medium Enterprises (로짓분석을 통한 중소기업 정책자금 지원의 위험예측력에 대한 연구)

  • Choi, Chang-Yeoul;Ham, Hyung-Bum
    • Management & Information Systems Review
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    • v.28 no.3
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    • pp.1-23
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    • 2009
  • Prior bankruptcy studies have established that bankrupt firm's pre-filing financial ratios are different from those of healthy firms or of randomly selected going concerns. However, they may not be sufficiently different from the financial ratios of other firms in financial distress to allow the development of a ratio-based model that predicts bankruptcy with reasonable accuracy. As the result, in the multiple discriminant model, independent variables divided firms into bankrupt firms and healthy firms are retained earnings to total asset, receivable turnover, net income to sales, financial expenses, inventory turnover, owner's equity to total asset, cash flow to current liability, and current asset to current liability. Moreover four variables Retained earnings to total asset, net income to sales, total asset turnover, owner's equity to total asset indicate that these valuables classify bankrupt firms and distress firms. On the other hand, Owner's Equity to borrowed capital, Ordinary income to Net Sales, Operating Income to Total Asset, Total Asset Turnover and Inventory Turnover are selected to predict bankruptcy possibility in the Logistic regression model.

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Hiker Mobility Model and Mountain Distress Simulator for Location Estimation of Mountain Distress Victim (산악 조난자의 위치추정을 위한 이동성 모델 및 조난 시뮬레이터)

  • Kim, Hansol;Cho, Yongkyu;Jo, Changhyuk
    • Journal of the Korea Society for Simulation
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    • v.31 no.3
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    • pp.55-61
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    • 2022
  • Currently police and fire departments use a Network/Wifi/GPS based emergency location positioning system established by mobile carriers to directly link with the device of the people who request the rescue to accurately position the expected location in the call area. However in the case of mountain rescue it is difficult to rescue the victim in golden time because the location of the search area cannot be limited when the victim is located in a radio shadow area of the mountain or the device power is off and this situation become worse if victim fail to report 911 by himself due to the injury. In this paper, we are expected to solve the previous problem by propose the mobile telecommunication forensic simulator consist of time series of cell information, human mobility model which include some general and specific features (age, gender, behavioral characteristics of victim, etc.) and intelligent infer system. The results of analysis appear in heatmap of polygons on the map based on the probability of the expected location information of the victim. With this technology we are expected to contribute to rapid and accurate lifesaving by reducing the search area of rescue team.

Development of Asphalt Concrete Rutting Model by Triaxial Compression Test (삼축압축시험을 이용한 아스팔트 혼합물의 소성변형 파손모형 개발)

  • Lee, Kwan-Ho;Hyun, Seong-Cheol
    • Journal of the Korean Society of Hazard Mitigation
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    • v.9 no.1
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    • pp.57-64
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    • 2009
  • This study intends to evaluate of the characteristics of pavement deformation and develop the model for prediction model in the asphalt layer using a regression analysis. In test, there are two different asphalt binders and 5 different aggregate types. The air voids of hot mix asphalt are 6% and 10% for target value. Repeated triaxial compression test with 3 different confining pressures was used for test at 3 different test temperatures. It is going to verify the main parameters for permanent deformation of HMA and to develop the distress model. This paper is to figure out the factor affecting the pavement deformation, and then to develop model the pavement deformation for asphalt mixture. Also, the reliability of prediction model has been studied. The permanent deformation prediction model for asphalt mixtures with temperature, loading time, and air voids has been developed and the proposed permanent deformation prediction model has been validated by using the multiple regression approach which is called Statistical Package for the Social Sciences(SPSS).

Development of the Permanent Deformation Prediction Model of 19mm Dense Grade Asphalt Mixtures (19mm 밀입도 아스팔트 혼합물의 소성변형 예측 모델 개발)

  • Park, Hee-Mun;Choi, Ji-Young;Park, Seong-Wan
    • International Journal of Highway Engineering
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    • v.7 no.4 s.26
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    • pp.1-8
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    • 2005
  • Permanent Deformation is one of the most important load-related pavement distresses in asphalt pavements. The Korean Pavement Design Guide currently being developed adopted the mechanistic-empirical approach and needed the pavement distress prediction models. This study intends to develop the model for prediction of permanent deformation in the asphalt layer and estimate the pavement performance. The objectives of this paper are to figure out the factors affecting the permanent deformation and then develop the permanent deformation prediction model for asphalt mixtures. The repeated triaxial load test was Performed on the 19mm dense graded asphalt mixture with variation of temperature and air void. Results from the laboratory tests showed that temperature and air void in asphalt mixtures have significantly influenced on the factors in prediction model. The permanent deformation prediction model for 19m dense grade asphalt mixtures has been developed using the multiple regression approach and validated the proposed permanent deformation prediction model.

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A Thermal Conductivity Model for Hydrating Concrete Pavements

  • Jeong Jin-Hoon;Kim Nakseok
    • Journal of the Korea Concrete Institute
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    • v.16 no.1 s.79
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    • pp.125-129
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    • 2004
  • Hydrating concrete pavement is typically subjected to temperature-induced stresses that drive cracking mechanisms at early concrete ages. Undesired cracking plays a key role in the long-term performance of concrete pavement systems. The loss of support beneath the concrete pavement due to curling caused by temperature changes in the pavement may induce several significant distresses such as punch out pumping, and erosion. The effect of temperature on these distress mechanisms is both significant and intricate. Because thermal conductivity dominates temperature flow in hydrating concrete over time, this material property is back-calculated by transforming governing equation of heat transfer and test data measured in laboratory. Theoretically, the back- calculated thermal conductivity simulates the heat movements in concrete very accurately. Therefore, the back- calculated thermal conductivity can be used to calibrate concrete temperature predicted by models.

Time-varying Co-movements and Contagion Effects in Asian Sovereign CDS Markets

  • Cho, Daehyoung;Choi, Kyongwook
    • East Asian Economic Review
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    • v.19 no.4
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    • pp.357-379
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    • 2015
  • We investigate interconnectedness and the contagion effect of default risk in Asian sovereign CDS markets since the global financial crisis. Using dynamic conditional correlation analysis, we find that there are significant co-movements in Asian sovereign CDS markets; that such co-movements tend to be larger between developing countries than between developed and developing countries; and that in the co-movements intra-regional nature is stronger than inter-regional nature. With the Spillover Index model, we measure contagion probabilities of sovereign default risk in CDS markets of seven Asian countries and find evidence of contagion effects among six of them; Japan is the exception. In addition, we find that these six countries are affected more by cross-market spillovers than by their own-market spillovers. Furthermore, a rolling-sample analysis reveals that contagion in the Asian sovereign CDS markets expands during episodes of extreme economic and financial distress, such as the Lehman Brothers bankruptcy, the European financial crisis, and the US-credit downgrade.

A Study on Development of the Concrete Pavement Condition Index (콘크리트 포장상태 평가지수의 개발에 관한 연구)

  • Kwon, Soo-Ahn;Kim, Nam-Ho;Seo, Young-Chan
    • International Journal of Highway Engineering
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    • v.2 no.3
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    • pp.145-153
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    • 2000
  • Pavement evaluation is a fundamental component for rational pavement management. Optimal rehabilitation method and the priority of rehabilitation should be based on the evaluation data. Some types of pavement condition index are needed for objective evaluation of Pavement condition and management of road network. In this study a expressway concrete pavement condition index model is developed through regression analysis that correlates panel rating with distress measurement from the test sections. The derived condition index can be used for network level PMS for the expressway concrete pavement. Correlation coefficient of the model was 0.68. The selected independent variables were International Roughness Index, crack and area of patching.

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Concept Analysis of Suffering (고통(Suffering) 개념 분석)

  • Gang, Gyeong-A
    • The Korean Nurse
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    • v.36 no.2
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    • pp.39-48
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    • 1997
  • There is a need to define the concept of suffering more appropriate in the context of Korean culture. This research is an attempt to reanalyze the concept of suffering by applying Walker & Avant's process of concept analysis. The steps of concept analysis are : 1. Select a concept. 2. Determine the aims or purpose of the analysis. 3. Identify all uses of the concept that you can discover. 4. Determine the defining attributes. 5. Construct model, contrary, borderline, related and invented cases. 6. Identify antecedents and consequences. 7. Define empirical referents. The concept of suffering can be defined as follows: Suffering is a fundamental and inevitable experience of all human beings. When each individual experiences loss, damage and pain which threaten one's personal integrity, suffering is perceived differently among each individual depending on their personal inner factors, one's significant others, exterior circumstances and stimuli, and the ultimate meaning of life. Suffering brings severe and unendurable distress which accompany despair, powerlessness, anxiety, bitterness, fear, anguish, guilt, depression, withdrawal and anger. The attributes of suffering were analyzed. Model case, contrary case, borderline case, related case, and invented case were described. Antecedents, consequences and empirical referents were explored. This concept analysis provides data for new insights of suffering. These findings suggests that appropriate nursing interventions aimed at relieving suffering of patients need to be developed and implemented more widely.

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