• Earthquakes and Structures
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• v.12 no.5
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• pp.489-499
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• 2017

The effects of past earthquakes have demonstrated the seismic vulnerability of confined masonry structures (CMSs) to earthquakes. The results of experimental analysis indicate that damage to these structures depends on lateral displacement applied to the walls. Seismic evaluation lacks an analytical approach because of the complexity of the behavior of this type of structure; an empirical approach is often used for this purpose. Seismic assessment and risk analysis of CMSs, especially in area have a large number of such buildings is difficult and could be riddled with error. The present study used analytical and numerical models to develop a simplified nonlinear displacement-based approach for seismic assessment of a CMS. The methodology is based on the concept of ESDOF and displacement demand and is compared with displacement capacity at the characteristic period of vibration according to performance level. Displacement demand was identified using the nonlinear displacement spectrum for a specified limit state. This approach is based on a macro model and nonlinear incremental dynamic analysis of a 3D prototype structure taking into account uncertainty of the mechanical properties and results in a simple, precise method for seismic assessment of a CMS. To validate the approach, a case study was considered in the form of an analytical fragility curve which was then compared with the precise method.

• Journal of the Economic Geographical Society of Korea
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• v.15 no.2
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• pp.304-313
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• 2012

Uncertainty increases as a result of environment change and change of individual decision-making in extreme weather. This study consider individual decision-making which has been not covered until now. The purpose of this study is making Agent-Based Model to predict it more accurate that how much change travel demand in heavy rain and heavy snow. Through this model, it can be utilized to forecast travel demand, changes in travel behavior and traffic patterns. It will be also possible to predict discomfort index and risk of accidents.

• Earthquakes and Structures
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• v.9 no.6
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• pp.1337-1353
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• 2015

Seismic upgrading of existing structures is a technical and social issue aimed at risk reduction. Sustainable design is one of the most important challenges in any structural project. Nowadays, many retrofit strategies are feasible and several traditional and innovative options are available to engineers. Basically, the design strategy can lead to increase structural ductility, strength, or both of them, but also stiffness regulation and supplemental damping are possible strategies to reduce seismic vulnerability. Each design solution has different technical and economical performances. In this paper, four different design solutions are presented for the retrofit of an existing RC frame with poor concrete quality and inadequate reinforcement detailing. The considered solutions are based on FRP wrapping of the existing structural elements or alternatively on new RC shear walls introduction. This paper shows the comparison among the considered design strategies in order to select the suitable solution, which reaches the compromise between the obtained safety level and costs during the life-cycle of the building. Each solution is worked out by considering three different levels of seismic demand. The structural capacity of the considered retrofit solutions is assessed with nonlinear static analysis and the seismic performance is evaluated with the capacity spectrum method.

• Earthquakes and Structures
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• v.9 no.5
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• pp.1069-1089
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• 2015

This paper investigates the limits and efficacies of the Fiber Reinforced Polymer (FRP) material for strengthening mid-rise RC buildings against seismic actions. Turkey, the region of the highest seismic risk in Europe, is chosen as the case-study country, the building stock of which consists in its vast majority of mid-rise RC residential and/or commercial buildings. Strengthening with traditional methods is usually applied in most projects, as ordinary construction materials and no specialized workmanship are required. However, in cases of tight time constraints, architectural limitations, durability issues or higher demand for ductile performance, FRP material is often opted for since the most recent Turkish Earthquake Code allows engineers to employ this advanced-technology product to overcome issues of inadequate ductility or shear capacity of existing RC buildings. The paper compares strengthening of a characteristically typical mid-rise Turkish RC building by two methods, i.e., traditional column jacketing and FRP strengthening, evaluating their effectiveness with respect to the requirements of the Turkish Earthquake Code. The effect of FRP confinement is explicitly taken into account in the numerical model, unlike the common procedure followed according to which the demand on un-strengthened members is established and then mere section analyses are employed to meet the additional demands.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.8
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• pp.181-189
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• 2021

The COVID-19 pandemic has impacted the tourism industry due to the resulting travel restrictions as well as a slump in demand among travelers. The tourism industry has been massively affected by the spread of coronavirus, as many countries have introduced travel restrictions in an attempt to contain its spread. In Vietnam, the government has largely been credited for the country's success in keeping COVID-19 transmission rates under control. Early awareness of the pandemic, appropriate, drastic, and people-centric measures, as well as public support, are the main factors behind the success of Vietnam. In that context, it is observed that people's travel demand has bounced back and this research will examine factors driving the public's travel intention in the post-crisis (pandemic) period. The survey was conducted on the Internet using questionnaires designed in the Google platform. Data was collected from April 16 to May 31, 2020, from 154 Vietnamese participants. Research findings demonstrate 4 direct and indirect determinants of travel intention. The strongest effects come from perceived behavioral control which is influenced by subjective well-being. Perceived risk negatively correlates with Self-efficacy and subjective well-being. Conducted in the context of post-COVID-19, the research implies that once the pandemic has been controlled, perceived risks, although still exist, insignificantly influence the public's travel intention.

• The Journal of Economics, Marketing and Management
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• v.9 no.2
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• pp.33-43
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• 2021

Purpose: This study aims to verify sellers' economic incentives for voluntarily disclosing negative information in online markets and provide practical guidelines to online sellers in terms of whether, when, and how sharing low quality to buyers increase sales. Research design, data and methodology: Our model examines the number of bidders in Internet auctions to measure potential demand and uses count data analysis following previous studies that have also analyzed the number of bidders in auctions. After checking over-dispersion and zero-inflation in our data, we have run a Poisson regression to analyze the effect of sharing negative information on sales. Results: This study presents a counterintuitive result that low-quality sellers can increase their demand by fully disclosing negative information in an online market, if appropriate risk-reducing methods are employed. Our finding thus shows that there exists economic incentive for online sellers to voluntarily disclose negative information about their products, and that the context of transactions may affect this incentive structure as the incentive varies across product categories. Conclusions: As the positive impact of disclosing negative information has rarely been studied so far, this paper contributes to the literature by providing a unique empirical analysis on the impact of sellers' honesty on sales. By verifying economic incentives of disclosing low quality with actual online sales data, this study suggests practical implications on information disclosure strategy to many online sellers dealing with negative information.

• Earthquakes and Structures
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• v.21 no.6
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• pp.627-639
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• 2021

Fragility curves are being more significant as a useful tool for evaluating the relationship between the earthquake intensity measure and the effects of the engineering demand parameter on the buildings. In this paper, the effect of different site conditions on the vulnerability of the structures was examined through the fragility curves taking into account different strength capacities of the precast columns. Thus, typical existing single-story precast RC industrial buildings which were built in Turkey after the year 2000 were examined. The fragility curves for the three typical existing industrial structures were derived from an analytical approach by performing non-linear dynamic analyses considering three different soil conditions. The Park and Ang damage index was used in order to determine the damage level of the members. The spectral acceleration (Sa) was used as the ground motion parameter in the fragility curves. The results indicate that the fragility curves were derived for the structures vary depending on the site conditions. The damage probability of exceedance values increased from stiff site to soft site for any Sa value. This difference increases in long period in examined buildings. In addition, earthquake demand values were calculated by considering the buildings and site conditions, and the effect of the site class on the building damage was evaluated by considering the Mean Damage Ratio parameter (MDR). Achieving fragility curves and MDR curves as a function of spectral acceleration enables a quick and practical risk assessment in existing buildings.

• Journal of the Korean Society of Safety
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• v.37 no.6
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• pp.71-80
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• 2022

Since the 2000s, the demand for private demolition works has been gradually increasing as the apartment housing market has been led by redevelopment and reconstruction. In the case of the military, the Ministry of National Defense is consolidating troops from each military unit to reorganize the unit structure in accordance with Defense Reform 2.0; the plan includes reducing the garrison used by each unit to 70% of its current level. Accordingly, the demand for demolition work in the military is also expected to increase. However, the military regulations do not reflect the relevant laws that have been revised recently. This study identifies regulations and system improvements for demolition work suitable for the military based on an analysis of accident cases that have occurred during demolition work, of domestic and foreign laws and regulations related to military demolition work, and of the problems with current military safety management at each stage of planning, design, and construction. The study subsequently proposes improvements for military demolition work, including budget execution adjustment, the establishment of training courses, on-site inspections, the development of guidelines for military demolition work, the provision of risk assessment standards, and the need for the qualification of equipment operators.

• Asia Marketing Journal
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• v.18 no.4
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• pp.125-138
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• 2017

The goal of the study is to understand how consumers' constraint as opposed to utility structure gives rise to final decision when consumers purchase more than one variant of product at a time, i.e., horizontal variety seeking or multiple-discreteness. Purchase and consumption decision not only produces utility but also involves some sort of cognitive pressure. Past consumption or last purchase is likely to be linked to this burden we face such as concern for obesity, risk of harm, and guilt for mischief. In this research, the existence and the role of dynamic constraint are investigated through a microeconomic utility model with multiple dynamic constraint. The model is applied to the salty snacks data collected from field study where burden for spiciness serves as a constraint. The results are compared to the conventional multiple discreteness choice models of static constraints, and policy implications on price discounts is explored. The major findings are that first, one would underestimate the level of consumer preference for product offerings when ignoring the carry-over of the concern from the past consumption, and second, the impact of price promotion on demand would be properly evaluated when the model allows for the role of constraint as both multiple and dynamic. The current study is different from the existing studies in two ways. First, it captures the effect of 'mental constraint' on demand in formal economic model. Second, unlike the state dependence well documented in the literature, the study proposes the notion of state dependence in different way, via constraint rather than utility.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.2
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• pp.496-506
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• 2021

This study examined the relationship between job stress and fatigue symptom of fire-fighting officials. The study subjects were 330 fire-fighting officials working at five fire stations in the D metropolitan city. The study survey was a structured self-administered questionnaire from September 1 to October 31, 2019. The level of fatigue symptoms and job stress were significantly higher (p<.0.001). By the sub-region, the level of fatigue symptoms and job demand were significantly higher (p=0.046), but the decision latitude, the supervisor support, and co-worker support were lower (p=0.006, p<0.001, and p<0.001, respectively). The level of fatigue symptom showed a significant positive correlation with the total score of job stress (r=0.348, p<0.05) and the job demand (r=0.301, p<0.05). In contrast, it showed a significant negative correlation with the decision latitude (r=-0.306, p<0.05), supervisor support (r=-0.340, p<0.05), and co-worker support (r=-0.355, p<0.05). Multivariate logistic regression showed that the odds ratio of the high-risk fatigue group was significantly higher in the high-risk group of job stress than in the low group of job stress (ORs=3.03, 95% CI=1.13~8.12). These findings suggest that the level of fatigue symptoms of fire-fighting officials is related significantly to job stress.