• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.4
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• pp.51-62
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• 2012

According to the Lighthill and Whitham's shock wave model, a shock wave exists even in a homogeneous speed condition. They referred this wave as unobservable- analogous to a radio wave that cannot be seen. Recent research has attempted to identify how such a counterintuitive conclusion results from the Lighthill and Whitham's shock wave model, and derive a new asymptotical shock wave model. The asymptotical model showed that the shock wave in a homogenous speed traffic stream is identical to the ambient vehicle speed. Thus, no radio wave-like shock wave exists. However, performance tests of the asymptotical model using numerical values have not yet been performed. We investigated the new asymptotical model by examining the implications of the new model, and tested it using numerical values based on a test scenario. Our investigation showed that the only difference between both models is in the third term of the equations, and that this difference has a crucial role in the model output. Incorporation of model parameter${\alpha}$ is another distinctive feature of the asymptotical model. This parameter makes the asymptotical model more flexible. In addition, due to various choices of ${\alpha}$ values, model calibration to accommodate various traffic flow situations is achievable. In Lighthill and Whitham's model, this is not possible. Our numerical test results showed that the new model yields significantly different outputs: the predicted shock wave speeds of the asymptotical model tend to lean toward the downstream direction in most cases compared to the shock wave speeds of Lighthill and Whitham's model for the same test environment. Statistical tests of significance also indicate that the outputs of the new model are significantly different than the corresponding outputs of Lighthill and Whitham's model.

• Journal of Life Science
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• v.29 no.11
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• pp.1258-1266
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• 2019

Yangkyuksanhwa-Tang (YKSH), consisting of nine different herbs, is commonly used in Soyangin-type individuals with stroke, based on the Sasang Constitution Theory in Korea. However, no evidence has yet confirmed a beneficial effect of YKSH in ischemic stroke treatment. In this study, we investigated the effects of YKSH on ischemic brain injury in a mouse model of cerebral ischemia. Focal cerebral ischemia in mice was induced by photothrombosis, and behavioral recovery was evaluated. Infarct volume, inflammation, and newly generated cells were evaluated by histology and immunochemistry. YKSH treatment resulted in a significant recovery from the motor impairments induced by focal cerebral ischemia, as determined with wire grip and rotarod tests. YKSH treatment also decreased the infarct volume and the number of cells positive for tumor necrosis factor-${\alpha}$ and myeloperoxidase when compared with a vehicle-treated control group. By contrast, YKSH treatment considerably increased the number of cells positive for glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1, as well as the number of cells doubly positive for Ki67/doublecortin when compared with the vehicle-treated group. These results suggest that YKSH treatment attenuated the infarct size by anti-inflammatory action, astrocyte and microglia activation, and neuronal proliferation, thereby facilitating neurofunctional recovery from a cerebral ischemic assault. YKSH could therefore be a potential treatment for neurofunctional restoration of the injured brains of patients with stroke.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4660-4670
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• 2022

Hydroxyurea (HU) is a novel salt-free reductant used potentially for the separation of U/Pu in the advanced PUREX process. In this work, the radiation stability of HU were systematically investigated in solution by examining the effects of the type of rays (α, β, and γ irradiations), the absorbed dose (10-50 kGy), and the HNO₃ concentration (0-3 mol L^-1). The influence degree on HU radiolysis rates followed the order of the absorbed dose > the ray type > the HNO₃ concentration, but the latter two had moderate effects on HU radiolysis products where NH₄⁺ and NO₂^- were found to be the most abundant ones, suggesting that the differences of α, β, and γ rays should be considered in the study of irradiation effects. The radiolysis mechanism was explored using density functional theory (DFT) calculations, and it proposed the dominant radiolysis paths of HU, indicating that the radiolysis of HU was mainly a free radical reaction among ·H, e_aq^-, H₂O, intermediates, and the radiolytic free radical fragments of HU. The results reported here provide valuable insights into the mechanistic understanding of HU radiolysis under α, β, and γ irradiations and reliable data support for the application of HU in the reprocessing of spent fuel.

• Journal of Korean Academy of Nursing
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• v.26 no.4
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• pp.782-798
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• 1996

This study was a survey done for the purpose of constructing a nursing theory according to Korean culture and to identify the traditional Korean view of humans and the expectations of the sick role, and to confirm changes from the traditional view of humans and expectations of the sick role according to general characteristics of the population. The subjects were all adults over 18 years old. 517 who lived in six large cities and 191 who lived in five rural communities. Data collection was done from November 19th, 1994 to January 19th, 1995 using a tool to measure the traditional view of humans and expectations of the sick role which was developed by the investigator through a literature review. Collected data were analyzed using frequency, percent, Cronbach alpha, 1-test, F-test and Scheffe post hoc contrasts, with the SAS program. The results of this study are summerized as follows : 1. The Traditional view of human score for all subject was 49.92, which shows that Korean traditional view of human is moderate. High scored items were "human need to live by making harmony with nature, not by overcoming the nature" (3.44), "Filial duty to parents and elders is important" (3.31), "Think of family more than a individual" (2.96). 2. The differences in the traditional view of humans between residential districts showed that the residents of Chungbuk(56.00), Kyungbuk(55.26), Chonbuk(51.32), Taegu(50.59) had a more traditional view of humans than those in Pusan(45.42) and Seoul (47.27). 3. The differences in the traditional view of humans according to general characteristics showed that rural community residents, males, older people, people with lower levels of education, married and house-resident groups had a significantly higher traditional view of humans than urban residents, females, younger people, people with a higher levels of education, single and apartment-resident groups. There were differences according to religion and job. Buddhism had a higher traditional view of humans than those of atheism, Christianity and Catholicism and physical workers, a significantly highers score, than technicians and professional workers. 4. Daily expected task performance during illnesses was lowest for patients with stroke (2.16) and psychosis(2.40), in which case almost no daily general tasks were expected, followed by arthritis 4.06, peptic ulcer 4.79, headache 4.99 and cough 5.58. The amount of expected role exemption during illnesses was also highest for stroke(2.25), followed by psychosis(2.08), arthritis(1.64), peptic ulcer(1.29), headache(1.16) and cough(1.09). The amount of daily task performance in the acute stage(3.05) was significantly lower than that of convalescent stage(4.95). 5. Total expectation of role exemption according to general characteristics showed that there was no significant differences in urban /rural community, marriage, level of education and religion. By sex, women showed higher expectation of role exemption during illnesses than men. By age, the 31-40 year old group showed lower expectation of role exemption than the 41-50 year old group or over the 61 year old group.or over the 61 year old group.

• Korean Journal of Clinical Pharmacy
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• v.25 no.4
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• pp.238-245
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• 2015

Background: Pharmacy schools newly adopted a 6-year program strengthening clinical knowledge since 2011 in Korea. The clinical training under the guidance of preceptors at hospital sites is a requisite for pharmacy students during the last year of undergraduate course. It has been rarely studied on the hospital pharmacists' perspective regarding being a preceptor or teaching pharmacy students. Objectives: This study aimed to examine the hospital pharmacists' intention toward student training and to identify the relevant factors among the individual pharmacists' characteristics and working environment within the theoretical frame of the Theory of Planned Behavior (TPB). Method: A mail-survey was conducted for pharmacists working in tertiary hospitals in Seoul and Incheon. The survey questionnaire consisting of 131 questions with a 5-likert scale was developed for investigating pharmacists' attitude, subjective norm, perceived behavioral control and the intention to teach pharmacy students as well as other demographic variables. To estimate the construct validity of components, factor analysis was conducted and Cronbach's alpha was calculated to estimate the reliability of the observed variables. Statistical analyses of one-way variance analysis and multiple regression analysis were performed using SPSS 18.0. Results: The survey response rate was 53% (116/210) and the three constructs of attitude (r = .519), subjective norm (r = .233) and perceived control (r = .392) have appropriate correlations with the intention, proving the appropriateness of using the TPB model. Pharmacists working in inpatient (mean = 3.45) and outpatient clinics (mean = 3.34) generally showed positive intention for teaching. The attitude (${\beta}=.432$, p < 0.01) and perceived control (${\beta}=.270$, p < .01) constructs were significant predictors of the intention. Both age (r = 0.246, p = 0.017) and length of career (r = 0.310, p = 0.002) were positively related with the perceived control. Conclusion: Hospital pharmacists showed generally positive intention to provide student training in spite of the concern on their limited perceived behavioral control. Future research to find the actual barriers pharmacists faced in educating students need to be conducted.

• The Journal of the Korea Contents Association
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• v.17 no.4
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• pp.606-620
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• 2017

The purpose of this study was to develop and validate a Children's Play Disposition Scale(CPDS) which could be used to evaluate children's play patterns and preferences. The participants of this study were parents of 437 5-7-year-old children (age range from 51months to 106months). Preliminary items were developed through a review of relevant research, multiple intelligence theory and scales, confirmation of item adequacy and content validity. After the content validity was confirmed by experts, these items were edited down to a final list of 27 items representing 6 factors identified by exploratory factor analysis. The 6 factors of the scale consists of initiative, linguistic activity, logical-mathematical activity, art and craft, physical activity, and sensitivity respectively. Concurrent validity was established by using correlations between each factor of the CPDS and sub-factors and the total scores of Multiple Intelligence Checklist for preschoolers (Multiple Intelligence Institute Co., Ltd, 2008) and Multiple Intelligence Checklist for elementary schoolers (Multiple Intelligence Institute Co., Ltd, 2007). In addition, the reliability of each factor, as measured by Cronbach's ${\alpha}$, ranged from .53 to .79. The CPDS provides the developmental and educational information for strengthening children's developmental forte and for supporting children's developmental weakness. This scale can be used on developing children's play contents and guiding play methods in the future.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.511-523
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• 2005

The purpose of this study is to analyze the 1st and 2nd Korea Earth Science Olympiad (KESO) items, in order to find informations to enhance item quality. To do this, internal and external item classification frameworks are developed. Item difficulty (P), discrimination index (DI), correlation, and reliability are estimated by using classical test theory. Generalizability is also estimated by applying the generalizability theory. The results of item classification are as follows: (1) ‘Geology’, ‘astronomy’ and ‘data analysis and interpretation’ are dominant in content and inquiry process domain, respectively. Nearly every item has textbook context. (2) There is no difference between the preliminary and final tests in terms of their thinking skills sections. (3) As a whole, the ratio of items with pictures is high in item representation. However, multiple-choice and short answer items are more common in preliminary competition, and essay type items are found more often in final competition. The ratio of simple items is high in middle school section and preliminary competition, but composite items are dominant in high school section and final competition. The findings of item analysis are as follows: (1) In the middle school section, P is low and DI is moderate. But in the high school section, there is a considerable differences between science high schools and other high schools in general. (2) The highest correlation is reported between the scores of meteorology domain and total score in middle school, whereas in high school astronomy domain and total score show the highest correlation. (3) General high school section show the highest Cronbach $\alpha$ and generalizability. (4) General high school section show acceptable generalizability coefficient (> 0.80), but middle and science high school section should increase the number of items to reach acceptable generalizability level.

• Journal of Distribution Science
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• v.14 no.7
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• pp.83-90
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• 2016

Purpose - This study focuses on new type distribution channel that named as Omnichannel. Omnichannel is developed from Multichannel which is used in many distribution channels to buy or selling goods. Omnichannel basically needs an Information and Communications Technologies(ICT) to use, so researcher conduct a Technology Acceptance Model(TAM) to research model. Customer-brand relationship was used as dependent variable to focus on the role of Omnichannel. Research design, data, and methodology - The subject of this study is customer who purchase goods or service through omnichannel. Based on the literature from the preceding research analysis of TAM and customer-brand relationship, this study was constructed by the reference to previous studies, final research model design for figure out casual relationship among perceived ease of use, perceived usefulness, omnichannel use and customer-brand relationship. From 2016 February 3 to March 17, questionnaire survey targeted customers who use online and offline channels. 273 questionnaire survey had conducted, then, 252 survey data were available for empirical analysis. Researcher provide descriptive statistics for checking generality. Cronbach's alpha value was used to check the reliability of data. Exploratory factor analysis was used for purification of values and eigenvalue checking. After EFA, Confirmatory factor analysis was used to prepare structural equation modeling with executing structural equation modeling for confirming hypothesis which developed by researcher. Results - The main results of this empirical study are as follows. First, omnichannel's perceived ease of use has positive significant effect on perceived usefulness(estimate: 0.579). Moreover, omnichannel's perceived ease of use and perceived usefulness has positive significant effect on omnichannel use(estimate: 0.325,0.648). Second, using omnichannel has positive significant effect on brand-customer relationship(estimate: 0.521). Every hypothesis adopted as researcher designed. This study found out the intermediate relationship between perceived ease of use and omnichannel use by investigating hypothesis. Conclusions - Base on the empirical result, this study confirmed that TAM theory perceived has relation with omnichannel. First, factors of TAM has positive effect on omnichannel use, so it highlights the important role of customer based interface and usefulness. Especially, perceived usefulness has high indirect influence on ease of use and use of omnichannel. It seems that when customers try to decide use or not use omnichannel, customers focus on percept benefits from omnichannel. Thus, a provider should applicate attractive price table, accurate product or service information and high switching cost strategy to emphasize the usefulness of omnichannel. Second, using omnichannel enhances the relationship between customers and brand, because there are more time and frequency to serve customers. It is important because good relationship between customers can increase the future's financial performance through word of mouse, positive brand image and loyalty to brand or company. Finally, despite of empirical result and implications, this study has limitations. First, there are only a few previous studies about omnicahnnel, so literature reviews are restricted. While set up the factors which can affect the use of omnichannel, next study should be considered with broader theories or models(ex: contingency theory). Second, omnichannel has developed from multichannel, so comparative analysis is needed between these methods because there is a possibility about different forte character of each distribution system on customer's consuming patterns.

• Research in Community and Public Health Nursing
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• v.6 no.1
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• pp.5-33
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• 1995

The objective of the study are two-fold: one is to explore the relationship between environment, organizational structure, and organizational effectiveness of public health centers in Korea, and the other is to examine the validity of contingency theory for improving the organizational structure of public health care agencies, with special emphasis on public health nursing administration. Accordingly, the conceptual model of the study consisted of three different concepts: environment, organizational structure, and organizational effectiveness, which were built up from the contingency theory. Data were collected during the period from 1st of May through 30th of June, 1990. From the total of 249 health centers in the country, one hundred and five centers were sampled non proportionally, according to the geopolitical distribution. Out of 105, 73 health centers responded to mailed questionnaire. The health centers were the unit of the study, and a various statistical analysis techniques were used: Reliability analysis(Cronbach's Alpha) for 4 measurement tools; Shapiro-Wilk statistic for normality test of measured scores of 6 variables: ANOVA, Pearson Correlaion analysis, regressional analysis, and canonical correlation analysis for the test of the relationships and differences between the variables. The results were. as follows : 1. No significant differences between forma lization, decision-making authority and environmental complexity were found(F=1.383, P=.24 ; F=.801, P=.37). 2. Negative relationships between formalization and decision-making authority for both urban and rural health centers were found(r=-.470, P=.002 ; r=-.348, P=.46). 3. No significant relationship between formalization and job satisfaction for both urban and rural health centers were found (r=-.242, P=.132, r=-.060, P=.739). 4. Significant positive relationship between decision - making authority and job satisfaction were found in urban health centers (r=.504, P=.0009), but no such relationship was observed in rural health centers. Regression coefficient between them was statistically significant($\beta=1.535$, P=.0002), and accuracy of regression line was accepted (W=.975, P= .420). 5. No significant relationships among formalization and family planning services, maternal health services, and tuberculosis control services for both urban and rural health centers were found. 6. Among decision-making authority and family planning services, maternal health services, and tuberculosis control services, significant positive relationship was found between de cision-making authority and family planning services(r=.286, P=.73). 7. A significant difference was found in maternal health services by the type of health centers (F=5.13, P=.026) but no difference was found in tuberculosis control services by the type of health centers, formalization, and decision-making authority. 8. A significant positive relationships were found between family planning services and maternal health services and tuberculosis control services, and between maternal health services and tuberculosis control services (r=-.499, P=.001 ; r=.457, P=.004 ; r=.495, P=.002) in case of urban health centers. In case of rural health centers, relationships between family planning services and tuberculosis control services, and between maternal health services and tuberculosis control services were statistically significant (r=.534, P=.002 ; r=.389, P=.027). No significant relationship was found between family planning and maternal health services. 9. A significant positive canonical correlation was found between the group of independent variables consisted of formalization and de cision-making authority and the group of dependent variables consisted of family planning services, maternal health services and tuberculosis control services(Rc=.455, P=.02). In case of urban health centers, no significant canonical correlation was found between them, but significant canoncial correlation was found in rural health centers(Rc=.578, P=.069), 10. Relationships between job satisfaction and health care productivity was not found significant. Through these results, the assumed relationship between environment and organizational structure was not supported in health centers. Therefore, the relationship between the organizational effectiveness and the congruence between environment and organizational structure that contingency theory proposes to exist was not able to be tested. However decision-making authority was found as an important variable of organizational structure affecting family planning services and job satisfaction in urban health centers. Thus it was suggested that decentralized decision making among health professionals would be a valuable strategy for improvement of organizational effectiveness in public health centers. It is also recommended that further studies to test contingency theory would use variability and uncertainty to define environment of public health centers instead of complexity.

• The Journal of Korean Society for School & Community Health Education
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• v.9 no.2
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• pp.15-31
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• 2008

Objective: This study is a quasi-experimental study by nonequivalent control group pretest-posttest design, performed in order to identify whether the program developed on the basis of Ajzen(1988, 1991)'s theory of planned behavior (TPB) for predicting the safety behavior of students of department of dental technology affects intention toward safety behavior and general behavior. Therefore, the purpose of this study is to identify whether the safety education in laboratories in which knowledge is reinforced on the basis of the TPB theory affects safety behavior. Methodology: The theoretical framework of this study was established on the basis of the TPB by Ajzen(1988, 1991). This study was performed between May 20 and December 5, 2006, and the subjects included 101 in the experimental group and 98 in the control group, a total of 199. The experimental group was educated through six 50-minute sessions (twice a week) for three weeks. The experimental group was pretested, educated, and then asked to answer the pro-questionnaire after finishing the sixth session, but the control group was free from intervention. The research tool in this study was developed by the authors with reference to the process of tool development used in Schifter and Ajzen (1985) based on Ajzen and Fishbein(1980)'s tool development guide. Results: The data were analyzed through SPSS 14.0 version. The reliability test of attitude, subjective norm, perceived norm, intention, and behavior toward safety behavior as TPB variables was calculated of Cronbach's alpha coefficient, and general characteristics and the homogeneity test of the experimental and the control groups were analyzed through t test and $X^2$ test. According to the results of the analysis, the experiment group may be higher than the control group after the safety education in the scores of attitude, the subjective norm, the perceived norm, and the intention toward safety behavior as TPB independent variables showed no significant difference, but there was significant difference in the behavior and the knowledge. Meanwhile, according to the results of the pretest and posttest, eleven items in the experimental group and two items in the control group showed significant difference in the behaviors, and twelve in the former and four in the latter were significantly different in the knowledge. Conclusion: The safety education program developed on the basis of TPB was identified to enhance safety behavior and knowledge. Therefore, the safety education program used in this study for students of department of dental technology may be utilized as database for safety education in the department of dental technology.