• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.759-766
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• 2008

Road classification system is the first step for determining the road function and design standards. Currently, roads are classified by various indices such as road location and function. In this study, we classify road using various traffic indices as well as to identify traffic characteristics for each type of road. To accomplish the objectives, mixture model was applied for classifying road and analyzing traffic characteristics using traffic data that observed at permanent traffic count stations. A total of 8 variables were applied: annual average daily traffic(AADT), $K_{30}$ coefficient, heavy vehicle proportion, day volume proportion, peak hour volume proportion, sunday coefficient, vacation coefficient, and coefficient of variation(COV). A total of 350 permanent traffic count points were categorized into three groups : Group I (Urban road), Group II (Rural road), and Group III (Recreational road). AADT were 30,000 for urban, 16,000 for rural, and 5,000 for recreational road. Group III was typical recreational road showing higher average daily traffic volume during Sunday and vacational periods. Group I showed AM peak and PM peak, while group II and group III did not show AM peak and PM peak.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5C
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• pp.293-301
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• 2008

Soil profiling is one of the most important work among geotehnical engineering practice. Generally, soil profile is estimated from the observation of soil samples during subsurface exploration but such estimation also includes some experiencing aspects such as flushed water from the borehole, slime colour, boring speed and so on. In addition, since the capacity of hydraulic drill rig is significantly increased, thin layers might be easily missed. So, continuous soil profile is almost impossible over all depth to be bored from conventional subsurface exploration. While CPT or CPTu can serve continuous soil profile information over all depth generally in 5cm interval. Many charts or methods for soil profile from CPT result have been proposed during last several decades over the world. However they have not been verified in local ground condition in Korea. In this research, CPT results and soil classification results based on USCS were compiled from 17 sites over the Korea. Soil classification results by using 7 CPT soil classification charts were compared with those of USCS for the compiled database. Most proper CPT soil classification chart for Korean soil characteristics was evaluated and effective parameters for the soil classification from CPT were discussed. Finally interrelationship between CPT soil classification chart and USCS soil classification was evaluated.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.363-374
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• 2023

This study is a descriptive research study to confirm the care efficacy and empathy competency of nursing hospital nurses and analyze the factors to improve person-centered care behavior, provide theoretical and practical information accordingly, and prepare basic data. The study collected data from March 20, 2023 to April 20, 2023, targeting 146 nurses at a nursing hospital for the elderly in C region located in G province, and finally analyzed a total of 144 copies. Using IBM SPSS/25, descriptive statistics t-test, ANOVA, and correlation multiple regression analysis were analyzed. As a result of analyzing the variables that affect the subject's person-centered care by hierarchical multiple regression, the higher the caring efficacy and empathy capacity, the more the person-centered care was affected, and the explanatory power was 31.5%. As a result of this study, empathy competency and care efficacy were found to have an effect on person-centered care. It is thought that various measures should be prepared to improve the care efficacy and empathy competency for the efficient nursing performance of person-centered care of nursing hospital nurses.

• The Journal of Bigdata
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• v.7 no.2
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• pp.235-244
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• 2022

The rental history data of public bicycles in Seoul were analyzed to examine how pandemic phenomena such as COVID-19 caused changes in people's micro mobility. Data for 2019 and 2021 were compared and analyzed by dividing them before and after COVID-19. Data were collected from public data portal sites, and data marts were created for in-depth analysis. In order to compare the changes in the two periods, the riding direction type dimension and the rental station type dimension were added, and the derived variables (rotation rate per unit, riding speed) were newly created. There is no significant difference in the average rental time before and after COVID-19, but the average rental distance and average usage speed decreased. Even in the mobility of Ttareungi, you can see the slow rhythm of daily life. On weekdays, the usage rate was the highest during commuting hours even before COVID-19, but it increased rapidly after COVID-19. It can be interpreted that people who are concerned about infection prefer Ttareungi to village buses as a means of micro-mobility. The results of data mart-based visualization and analysis proposed in this study will be able to provide insight into public bicycle operation and policy development. In future studies, it is necessary to combine SNS data such as Twitter and Instagram with public bicycle rental history data. It is expected that the value of related research can be improved by examining the behavior of bike users in various places.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.2B
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• pp.159-167
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• 2010

The purpose of this study is to get the adjusted radar rainfalls by ANN(Artificial Neural Network) method. In the case of radar rainfall, it has an advantage of spatial distribution characteristics of rainfall while point rainfall has an advantage at the point. Therefore we adjusted the radar rainfall by ANN method considering the advantages of two rainfalls of radar and point. This study constructed two ANN models of Model I and Model II for radar rainfall adjustment. We collected the three rainfall events and adjusted the radar rainfall for Anseong-cheon basin. The two events were inputted into the Modeland Model to derive the optimum parameters and the rest event was used for validation. The adjusted radar rainfalls by ANN method and the raw radar rainfall were used as the input data of ModClark model which is a semi-distributed model to simulate the runoff. As the results of the simulation, the runoff by raw radar rainfall were overestimated but the peak time and peak runoff from the adjusted rainfall by ANN were well fitted to the observed hydrograph.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.1A
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• pp.9-18
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• 2009

This paper introduces the application of DE (Differential Evolutionary) method for the estimation of tensile force of the externally prestressed tendon. The proposed technique, a SI (System Identification) method using the DE algorithm, can make global solution search possible as opposed to classical gradient-based optimization techniques. The numerical tests show that the proposed technique employing DE algorithm is a useful method which can detect the effective nominal diameters as well as estimate the exact tensile forces of the externally prestressed tendon with an estimation error less than 1% although there is no a priori information about the identification variables. In addition, the validity of the proposed technique is experimentally proved using a scale-down model test considering the serviceability state condition without and with the loss of the prestressed force. The test results prove that the technique is a feasible and effective method that can not only estimate the exact tensile forces and detect the effective nominal diameters but also inspect the damping properties of test model irrespective of the loss of the prestressed force. The 2% error of the estimated effective nominal diameter is due to the difference between the real tendon diameter with a wired section and the FE model diameter with a full-section. Finally, The accuracy and superiority of the proposed technique using the DE algorithm are verified through the comparative study with the existing theories.

• Journal of Korea Entertainment Industry Association
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• v.13 no.8
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• pp.583-593
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• 2019

The purpose of this study was to investigate the relation between and subjective instability pain behavior (SIPB) and physical instability test(PIT) according to the presence of characteristic past histories(CPH) in people with chronic low back pain(CLBP). Forty CLBP subjects participated in this study. The presence of four characteristics past histories(long term history, traumatic experience, sports activities, neurologic sign) were examined. According to presence number(PN) of CPH, subjects were divided into 5 groups[group 1(PN:0): n=8, group 2(PN:1): n=8, group 3(PN:2): n=8, group 4(PN:3): n=8, group 5(PN:4): n=8]. After 16 items were examined for the SIPBs, then Seven PITs were conducted, and the results were scored. The SIPBs and PITs were compared according to the presence numbers of CPH, and the relation between them was analyzed. There was a significant difference(p<.05) in both SIPB scores and PIT scores in the comparison of groups according to the presence number of CPH. There was high positive correlation between the presence numbers of CPH and SIPB score(r=.819, p=.000) and PIT score(r=.606, p=.000). Also, there was a correlation between SIPB score and PIT score(r=.571, p=.000). Based on the findings in the present study, the presence of three or more CPH in people with CLBP may be a useful variable in the diagnosis of lumbar instability. The combined findings of the three variables such as CPH, SIPB, and PIT can improve the accuracy of lumbar instability diagnosis.

• 한국노년학
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• v.31 no.3
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• pp.795-811
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• 2011

Recently, an interest on how to moderate parenting stress of grandparents is rising according to rising depression of grandparents of grandparents and grandchildren family(GGF) because of parenting stress So, this study tried to analyze moderating effects by setting social support and stress coping behaviors as moderator variable in order to know how much parenting stress of grandparents would influence their depression. For this purpose, we selected 369 cases of grandparents who were being provided social welfare service and to 334 cases out of them, did multigroup analysis using hierarchical regression analysis and structural equation model under spss Vor. 19.0 program. Followings are the results. First, the more parenting stress was high, the more depression high. But when social support was high, parenting stress low. And the more parenting stress was high, faith dependence, negative emotional expression and passive evasion as stress coping behaviors also high while problem reestablishment low. Second, emotional support, information support, and material support as social support had moderating effects in which parenting stress influenced depression while appraisal support had not. Third, faith dependence and low passive evasion as stress coping behaviors had moderating effects in influence of parenting stress to depression while problem reestablishment has not. On the one hand, emotional expression was meaningless in explaining moderating effects in connection with parenting stress. Through these, we draw a social welfare practical implication that could lift moderating effect of social support and stress coping behavior in between parenting stress and depression of grandparents of grandparents and grandchildren Family.

• Journal of Korea Entertainment Industry Association
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• v.5 no.1
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• pp.65-72
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• 2011

The major purpose of this study is to investigate the influencing factors toward continuance intention in e-learning services. For this purpose, we introduced Post Acceptance Model(PAM) proposed by Bhattacherjee(2001) as basic analysis framework. Based on the relevant literature reviews, this study posits seven characteristics, that is, contents quality, interactivity, expectation confirmation, perceived ease of use, perceived usefulness, user satisfaction, and continuance intention as key variables to describe the post acceptance behavior in e-learning services. Data have been collected from users who have used e-learning services and the research model and hypotheses were tested through covariance structural model analysis. The results of this study are summarized as follows. First, contents quality, interactivity, and expectation confirmation have positive influence upon perceived usefulness. Second, contents quality, interactivity, expectation confirmation, and perceived ease of use have positive influence upon user satisfaction. Lastly, perceived usefulness have positive effect on the user satisfaction, and perceived usefulness and user satisfaction positively related to continuance intention in e-learning services. The findings have significant implications for e-learning service providers and academic researchers.

• International Area Studies Review
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• v.15 no.1
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• pp.87-106
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• 2011

Using an event study, this paper investigates stock price reactions on Korean listed firms' convertible bond (CB) issue announcements over the sample period of January 2000 to November 2007. This study finds that on the Korean Security market, the CB issue announcements are associated with an increase in shareholder wealth on the announcement date. An information leakage by insider traders is also observable at preannouncement dates. Unlike the prior studies that indicate a prevailing negative effect on the announcements, this paper shows that domestic CB issue announcements as well as offshore ones yield a positive impact on the stock prices. This presents that in terms of stock price reactions to the CB issue announcements, the two CB issue markets show the positively same effects on shareholder wealth for the post-2000 period. For its drivers, this paper suggests that on the Korean market, firm size have negative relationship with the increase in the wealth incurred by the announcements. By contrast, an issue to maturity, a growth opportunity, and a relative issue size make a positive impact on it.