• Journal of Korea Water Resources Association
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• v.34 no.2
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• pp.155-167
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• 2001

The effects of bank crest width, slope steepness, soil properties, and soil compactness on the characteristics of levee breach due to overlfow were investigated through a series of experiments. Generally, the major factors influencing the breach phenomenon are compactness, soil properties. crest width, and slope steepness, in that order. Using proper soil, and ensuring enough compactness in bank construction are very essential for extending breach duration and reducing peak overflow ranges for the values of breach duration, breach width, width-to-depth ratio, and side slope of the breach section, proposed by Singh, MacDonald and Fread based on the field data for earth dam breaks were reasonable. We found that those criteria could also be applied to the phenomenon of levee breaching.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.5
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• pp.172-185
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• 2021

As the era of autonomous driving approaches, it is expected to have a significant impact on our lives. When autonomous driving cars emerge, it is necessary to develop an index that can evaluate autonomous driving cars as it enhance the productive value of the car by reducing the burden on the driver. This study analyzed how the autonomous driving era affects commuting time and commuting time satisfaction among office goers using a car in Gyeonggi-do. First, a nonlinear relationship (V) was derived for the commuting time and commuting time satisfaction. Here, the factors affecting commuting time satisfaction were analyzed through a binomial logistic model, centered on the sample belonging to the nonlinear section (70 minutes or more for commuting time), which is likely to be affected by the autonomous driving era. The analysis results show that the variables affected by the autonomous driving era were health, sleeping hours, working hours, and leisure time. Since the emergence of autonomous driving cars is highly likely to improve the influencing variables, long-distance commuters are likely to feel higher commuting time satisfaction.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.4
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• pp.93-106
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• 2020

This research explores how imported automobile companies can develop their strategies to improve the outcome of their recalls. For this, the researchers analyzed patterns of recall demand, classified recall types based on the demand patterns and examined response strategies, considering plans on how to procure parts and induce customers to visit workshops, recall execution capacity and costs. As a result, recalls are classified into four types: U-type, reverse U-type, L- type and reverse L-type. Also, as determinants of the types, the following factors are further categorized into four types and 12 sub-types of recalls: the height of maximum demand, which indicates the volatility of recall demand; the number of peaks, which are the patterns of demand variations; and the tail length of the demand curve, which indicates the speed of recalls. The classification resulted in the following: L-type, or customer-driven recall, is the most common type of recalls, taking up 25 out of the total 36 cases, followed by five U-type, four reverse L-type, and two reverse U-type cases. Prior studies show that the types of recalls are determined by factors influencing recall execution rates: severity, the number of cars to be recalled, recall execution rate, government policies, time since model launch, and recall costs, etc. As a component demand forecast model for automobile recalls, this study estimated the ARIMA model. ARIMA models were shown in three models: ARIMA (1,0,0), ARIMA (0,0,1) and ARIMA (0,0,0). These all three ARIMA models appear to be significant for all recall patterns, indicating that the ARIMA model is very valid as a predictive model for car recall patterns. Based on the classification of recall types, we drew some strategic implications for recall response according to types of recalls. The conclusion section of this research suggests the implications for several aspects: how to improve the recall outcome (execution rate), customer satisfaction, brand image, recall costs, and response to the regulatory authority.

• Steel and Composite Structures
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• v.44 no.2
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• pp.199-210
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• 2022

This study build finite element analysis (FEA) models describing the bending events of coiled tubing (CT) at the wellhead and trips into the hole, accurately provide the state of stress and strain while the CT is in service. The bending moment and axial force history curves are used as loads and boundary conditions in the diametrical growth models to ensure consistency with the actual working conditions in field operations. The simulation diametrical growth results in this study are more accurate and reasonable. Analysis the factors influencing fatigue and diametrical growth shows that the internal pressure has a first-order influence on fatigue, followed by the radius of the guide arch, reel and the CT diameter. As the number of trip cycles increase, fatigue damage, residual stress and strain cumulatively increase, until CT failure occurs. Significant residual stresses remain in the CT cross-section, and the CT exhibits a residual curvature, the initial residual bending configuration of CT under wellbore constraints, after running into the hole, is sinusoidal. The residual stresses and residual bending configuration significantly decrease the buckling load, making the buckling and buckling release of CT in the downhole an elastic-plastic process, exacerbating the helical lockup. The conclusions drawn in this study will improve CT models and contribute to the operational and economic success of CT services.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.2D
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• pp.183-190
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• 2009

In order to improve continuous success and stabilization of high-speed rail in the future, Using Frequency of high-speed rail should be enhanced by improving satisfaction of high-speed rail passenger. High-speed rail is needed to hold the priority in competition means by comparing the traits of service of domestic air lines. This study utilizes structural equation modeling to develop model for estimating factors influencing to service through conducting survey questionnaire. It also uses reliability analysis, correlation analysis, factor analysis to examine the rationalization of items and to establish hypothesis of this research. The results show that KTX contains 'inner service' item that is considered to be ameliorated and that domestic airline present low performance of 'outer service' item. In other words, moving section which partly is under a limited condition is needed to be improved. In addition, access to airport and transfer to other transportations have to be improved as they show the lowest satisfaction.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6D
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• pp.663-673
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• 2009

Driver's perceived curve radius is different from actual curve radius at curve sections. This is called visual distortion. It has effect on operation speed according to driver's perception and finally bad effect on safety at curve sections. At present, however, there is no research on quantitatively analysis of visual distortion and no criteria for curve section design considering the visual distortion. Therefore, this study focus on finding degree of visual distortion and suggesting design criteria by visual distortion analysis. The process of this study is as below; First, a calculaiton model of perceived curve radius was developed by survey using computer simulation. In this model, a dependent variable is perceived curve radius and an independent variable is geometric factors. Second, degree of visual distortion was calculated from ratio of perceived curve radius to actual curve radius. Finally, design criteria were suggested through influencing factor analysis of visual distortion at curve sections.

• Journal of The Korea Institute of Healthcare Architecture
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• v.30 no.1
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• pp.37-44
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• 2024

Purpose: The planning of medical facilities involves formulating a comprehensive medical basic plan, translating it into spatial dimensions through a space program. Feasibility assessment often relies on empirical methods like floor area per bed. However, with the shift towards specialized medical concepts, proportional scaling to bed numbers is challenging. This study proposes scale planning improvements during the feasibility assessment stage for comprehensive hospitals, analyzing cases using area determination factors and standard areas based on medical resources. Methods: The Korean Development Institute's Public Investment Management Center (KDI) identified issues in the scale determination of medical facilities in the Preliminary Feasibility Study Guidelines and investigated alternative approaches for determining the scale of a case that passed the preliminary feasibility study in 2019. The study assessed the feasibility of applying individual factors to determine not only the number of beds but also the scale at the sector and department levels. Additionally, a statistical analysis was conducted to examine the correlation between the total number of beds and various area determination factors. Results: Results suggest a strong correlation between total beds and major equipment needs, but in hospitals with <500 beds, this correlation weakens. Ward section scale is better calculated per ward type, not just total beds. Outpatient department scale depends on specialists, influencing treatment room numbers. Medical personnel play a crucial role in determining the scale of sections like rehabilitation therapy rooms, operating rooms, dialysis rooms, and overall facility scale.

• International Journal of Highway Engineering
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• v.13 no.3
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• pp.157-165
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• 2011

With respect to the trend of highway traffic accident, highway accident is in decline, whileas, the fatality is on an increasing trend. Thus, many efforts to decrease highway traffic accidents and improve the safety, are required. In particular, in case of highway, the management standard by grade for accident black spot is designated. Thus, investing the effect factors by grade for highway traffic accident is required in detail. Thus, in this study, the factors affecting the traffic accidents among the environmental factors based on the graded data for the accident black spot in the applicable section targeting the Seoul-Pusan Express Highway, were reviewed; accident forecasting model which would analyze the characteristics of the accidents for determining the accident grade, was developed. As a result of establishing a model by using Quantification Theory of Type II, considering the characteristics of the dependent and independent variables based on the geometric structure, 'the fixed variable' among the variables relating to the accident, for the variables influencing over the accident grade, 'the type of vans, a chassis and people', 'the trailers, special vehicles and chassis people' and 'the negligence of watching and cloudy weather' were analyzed as common factors, in case of 'horizontal alignment', 'longitudinal slope' and, 'barricade' respectively.

• The Journal of the Korea Contents Association
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• v.16 no.6
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• pp.627-635
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• 2016

The purpose of this study was to investigate the communication skill of a dental hygienist for the elderly. The self-administered questionnaire selected by convenience sampling method from January 2 to February 14, 2015, Seoul, Kyungki, Incheon regions final analysis section 233 to target dental hygienist working under a dentist institutions. This study analyzed collected data by t-test, ANOVA, pearson correlation coefficient, and multiple regression. According to multiple regression analysis results can be number of worker, the main task, living experience feelings adjusted variable, as a result work in the dental hospital(B=.292 SE=.074), more like the elderly preference(B=.282, SE=.141), the behavior of the elderly(B=-.223, SE=.043) found that the more positive the impact. Therefore, the more exposure for your understanding and the elderly relationships for the the elderly appeared to affect the communication skill necessary to develop training programs that can improve the communication skill of a dental hygienist and apply to be prepared for the coming aging society.

• Journal of the Korean Arthroscopy Society
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• v.8 no.1
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• pp.1-8
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• 2004

Purpose: This study examined clinical cure and patients' satisfaction degrees by factors influencing surgical operation results, after arthroscopic inside to out repair as a nonabsorbable suture material, in case of meniscal rupture. Materials and Methods: Materials were 110 cases of 95 patients who could make paces for over 12 months from August 1999 to June 2002. Results were evaluated by clinical cure and subjective satisfaction degrees. This study, concerning those results, analyzed age, term from taking pictures to taking surgical operation, rupture section, rupture length, rupture types, lesion of articular-cartilage, and effects of anterior cruciate ligament operation accompanied. Results: 84 cases(76%) were clinically cured, 98 cases(89%) were subjectively satisfied. In case of accompanying anterior cruciate ligament rupture, and in case that rupture length was below 2 cm, rates of clinical cure and patients subjective satisfaction were significantly high. In case of complex or degenerative rupture, patients satisfaction rates were higher when comparing with clinical cure rates. Conclusion: Various sutures are possible as well as available in case of arthroscopic meniscal inside to out repair using nonabsorbable suture material. It can be concluded that patients age is not absolte consideration in determining the suture of meniscus. In cases of complex rupture, degenerative rupture, ruptures companied by joint-cartilage injuries, considerate consideratin need be paid to choose patients and operations.