• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.163-170
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• 2008

According to the rules, a crash cushion is supposed to set up products that is satisfied with the standard of a performance test after performing the car crash test by road safety facilities and management guide. For development of crash cushion, performance should be estimated through the car crash test eventually. However, there is no reasonable design method which considers passenger's safety and only depend on crash test without an alternative plan. Therefore it incurs a loss materially and takes a lot. Therefore, we are asked to create a systematic design of the crash cushion. This study shows that a scientific basis of applying single degree of freedom when it designs the crash cushion after analyzing vehicle crash test data of crash cushion and also represents design of crash cushion through single degree of freedom response spectrum using calculated by crash test data on crash cushion.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.2D
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• pp.249-258
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• 2008

Korean engineering firms need to improve their performance in order to stay competitive in the globalize environments which has been led by some international movements including World Trade Organization (WTO) and Free Trade Agreements (FTA). There have been various activities and researches focusing on how to improve competitiveness of Korean engineering firms and the out-of-fashion Engineering Project Delivery System (EPDS) has repetitively identified as one of main barriers to deter advancements of Korean engineering industry. Therefore, this research attempted to investigate global standards of EPDS such as International Federation of Consulting Engineers (FIDIC), American Federal Acquisition Regulations (FAR), Brooks Act, and so on. The procedures of international EPDSs along with a few case studies were comprehensively analyzed and compared with Korean EPDS in order to propose recommendations of improving Korean EPDS. Some major differences between international and Korean EPDS were identified and they includes emphasis on qualifications of engineers and/or firms rather than their proposed cost, extensive use of long and short-list, common use of negotiation process, etc. Research findings are envisioned to guide the Korean public engineering sector to innovate Korean EPDS.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.557-570
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• 2023

The purpose of this study is to develop a digital-based non-face-to-face instructional design model for national public servants. For this purpose, we reviewed the direction of non-face-to-face instructional design based on previous research, and interviewed a total of 10 instructors and learners with experience in non-face-to-face education to identify the success factors of non-face-to-face instructional design for government employees. In addition, to ensure the validity of the instructional design model, a Delphi survey was conducted with experts in instructional design and educational management. As a result, the digital-based instructional design model for national public servants reflects the importance of learning objectives and content design to enhance learning motivation and improve educational effectiveness, and includes detailed implementation plans to support specific and clear performance activities for instructors in non-face-to-face education situations. The instructional design model developed through this study can be expanded as a standard for improving the quality of education in public human resource development, and can be used as a teaching and learning guide according to learner types and characteristics.

• Journal of The Korean Association For Science Education
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• v.43 no.6
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• pp.509-520
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• 2023

Scientific explanation is the main goal of scientists' scientific practice, and the science curriculum also includes developing students' abilities to construct scientific explanations as a major goal. Thus, clarifying its meaning is an important issue in the science education community. In this paper, the researchers identified three perspectives on 'scientific explanation' based on the scoping review method (Deductive-Nomological, Probabilistic, and Pragmatic explanation models). We argued that it is important to clarify and distinguish the meanings of 'scientific explanation' from other concepts used in science education, such as 'description', 'prediction', 'hypothesis', and 'argument' based on a review of the literature. It is also pointed out that there is a difference between 'scientific explanation' as a product and 'explaining scientifically' as communication, and several ways to revise achievement standard statements in the science curriculum are suggested, to guide students to construct scientific explanations and to help students to explain scientifically. By adopting the three scientific explanation models, the important factors to be considered were classified and organized, and examples of science learning activities for scientific explanation considering such factors were suggested. It is hoped that the discussion in this study will help establish clearer learning goals in science learning related to scientific explanation and aid the design of more appropriate learning activities accordingly.

• Journal of Industrial Convergence
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• v.21 no.11
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• pp.125-134
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• 2023

This study attemped to examine the effects of health care nursing policy education on nursing students' political efficacy, political participation, and political interest. It attempted to guide the direction of policy education within nursing curriculum. The subjects consisted of 89 nursing students of G-university from March 8, 2023, to June 21, 2023, including 44 in the experimental group and 45 in the control group. The health care nursing policy class was developed using the ADDIE(Analysis, Design, Development, Implementation, Evaluation) model of instructional design. Data analysis used the SPSS 25.0 program through mean, standard deviation, and independent sample t-test. The experimental group that participated in this education showed statistically significant improvement in political efficacy(t=2.34, p<.05) and intrinsic political efficacy(t=2.75, p<.05), as well as passive political participation score(t=2.22, p<.05) compared to before the intervention. Based on the findings of this study, it is suggested that health care nursing policy education should be structured to enhance external political efficacy and promote active political participation in future nursing curriculum.

• Journal of Korean Dental Hygiene Science
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• v.1 no.1
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• pp.47-55
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• 2018

The purpose of this study was to examine the influence of oral health education experience on needs for oral health education in children and adolescents in elementary and secondary schools. A self-administered survey was conducted on the students in elementary, middle and high schools located in the city of Mokpo, South Jeolla Province, from October 1 to 31, 2018. The data that were collected from 327 students were analyzed by SPSS 21.0. Statistical data on frequency, percentage, mean and standard deviation were obtained, and t-test, one-way ANOVA, correlation analysis and logistic regression analysis were carried out. The findings of the study were as follows: First, the subjects got 2.25 on a three-point scale in self-rated oral health status. This score was above average, which indicated that the students thought they were in good oral health. As for problems with oral health, dental caries was given the highest score of 2.48 on a five-point scale, followed by oral malodor with 2.35. Second, the students who experienced oral health education accounted for 69.1 percent, and the students who felt the need for this education represented 82.6 percent. As for educational content desired, the biggest group of 57.8 percent hoped to learn about how to prevent and manage dental caries, and the second largest group of 17 percent wanted to learn about how to take care of oral health during orthodontic treatment. Third, as a result of investigating the state of oral health education by the grade of school, the elementary school students had more oral health education experience than the middle and high school students, and the middle school students placed the most importance on the necessity of oral health education. The differences were statistically significant. Fourth, as a result of analyzing the correlation between oral health education experience and the necessity of oral health education, the students who had more oral health education experience asked more for this education, which implies that there was a statistically significant positive correlation. The findings of the study ascertained that oral health education should be provided for students in childhood and adolescence to boost the level of their oral health knowledge and change their oral health attitude in a positive manner. If oral health practice programs that connect schools, local communities and families with one another are developed to guide the oral health behaviors of teenagers in the right direction, it will make a contribution to the promotion of oral health.

• Korean Journal of Radiology
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• v.24 no.3
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• pp.235-246
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• 2023

Objective: It is difficult to predict the treatment response of tissue after stereotactic radiosurgery (SRS) because radiation necrosis (RN) and tumor recurrence can coexist. Our study aimed to predict tumor recurrence, including the recurrence site, after SRS of brain metastasis by performing a longitudinal tumor habitat analysis. Materials and Methods: Two consecutive multiparametric MRI examinations were performed for 83 adults (mean age, 59.0 years; range, 27-82 years; 44 male and 39 female) with 103 SRS-treated brain metastases. Tumor habitats based on contrast-enhanced T1- and T2-weighted images (structural habitats) and those based on the apparent diffusion coefficient (ADC) and cerebral blood volume (CBV) images (physiological habitats) were defined using k-means voxel-wise clustering. The reference standard was based on the pathology or Response Assessment in Neuro-Oncologycriteria for brain metastases (RANO-BM). The association between parameters of single-time or longitudinal tumor habitat and the time to recurrence and the site of recurrence were evaluated using the Cox proportional hazards regression analysis and Dice similarity coefficient, respectively. Results: The mean interval between the two MRI examinations was 99 days. The longitudinal analysis showed that an increase in the hypovascular cellular habitat (low ADC and low CBV) was associated with the risk of recurrence (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.46-4.91; P = 0.001). During the single-time analysis, a solid low-enhancing habitat (low T2 and low contrast-enhanced T1 signal) was associated with the risk of recurrence (HR, 1.54; 95% CI, 1.01-2.35; P = 0.045). A hypovascular cellular habitat was indicative of the future recurrence site (Dice similarity coefficient = 0.423). Conclusion: After SRS of brain metastases, an increased hypovascular cellular habitat observed using a longitudinal MRI analysis was associated with the risk of recurrence (i.e., treatment resistance) and was indicative of recurrence site. A tumor habitat analysis may help guide future treatments for patients with brain metastases.

• Journal of Korea Spatial Information System Society
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• v.5 no.1 s.9
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• pp.49-63
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• 2003

Recently, two international standard organizations, ISO and OGC, have done the work of standardization for GIS. Current standardization work for providing interoperability among GIS DB focuses on the design of open interfaces. But, this work has not considered procedures and methods for designing GIS DB. Eventually, GIS DB has its own model. When we share the data by open interface among heterogeneous GIS DB, differences between models result in the loss of information. Our aim in this paper is to revise the design guidelines for geographic information databases in order to make consistent spatial data models, logical structures, and semantic structure of populated geographical databases. In details, we propose standard guidelines which convert ISO abstract schema into relation model, object-relation model, object-centered model, and geometry-centered model. Furthermore, we provide sample models for applying these guidelines in commercial GIS S/Ws. Building GIS DB based on design guidelines proposed in the paper has the following advantages: the interoperability among databases, the standardization of schema definitions, and the catalogue of GIS databases through.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.404-411
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• 2009

Drinking water has lots of minerals, especially calcium, sodium, kalium, magnesium, and fluoride must be labelled on the bottle about their contents. Minerals like calcium, magnesium, and fluoride have influence to the tooth development. Appropriately taking some minerals, dental caries can be prevented somewhat degree. There is no guide line about innoxious minerals like calcium and magnesium, however, noxious mineral like fluoride, should be contained less than 2 mgF/L according to the current drinking water standard. Hereupon, it is necessary to recognize the concentration of fluoride in drinking water, so I studied 15 samples of domestic drinking water on sale about the concentration of calcium and magnesium, fluoride. The results obtained were as follows ; 1. 14 drinking waters in 15 samples showed various Ca concentration. The average Ca concentration is 34.68${\pm}$31.84 mg/L, the highest is 128.91${\pm}$1.85 mg/L and the lowest is 2.0${\pm}$0.02 mg/L. 2. 13 drinking waters in 15 samples indicate the Mg concentration. The average concentration is 9.22${\pm}$11.06 mg/L, the highest is 30.43${\pm}$0.75 mg/L and the lowest is 0.0 mg/L. 3. 11 drinking waters in 15 samples indicate the F concentration. The average concentration is 0.25${\pm}$0.33 mg/L, the highest is 1.13${\pm}$0.04 mg/L and the lowest is 0.01${\pm}$0.03 mg/L. All samples are satisfied the current drinking water standard, 2 mg F/L.

• Journal of the Korean GEO-environmental Society
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• v.20 no.6
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• pp.5-13
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• 2019

The international trend in soil nailed wall design has been evolved from the allowable stress design to limit state design and it is still currently ongoing. The design guidelines in Korea and Hong Kong still adopts the allowable stress design philosophy while those in others mostly do the limit state design. In this study, four soil nail design methods presented in the major design guidelines (U.S. FHWA GEC 7 (2015), Clouterre in France (1991), Soil nailing - best practice guidance in U.K. (CIRIA, 2005), Geoguide 7 in Hong Kong (2008) and Design standard for slope reinforcement work in Korea (KDS 11 70 15 f: 2016)) are described and analyzed in brief. The factor of safety and CDR (Capacity-to-Demand Ratio) which is used to measure the degree of conservatism of a design guide are obtained for the two cases. One is the design example presented in CIRIA (2005) and the other is in-situ loading test performed on the top of backfill of the soil nail wall to investigate the conservatism of design guidelines. It is revealed that the design method in overall stability of soil nail walls in domestic design method (CDR=0.78) is the most conservative and those by Clouterre (CDR=0.99, 1.09), Geoguide 7 (CDR=1.13, 0.97), U.S. FHWA (CDR=1.09, 1.07) and CIRIA (CDR=1.40, 1.16) in order from the second most conservative to the least conservative for the design example presented in CIRIA. For the in-situ loading test performed on the top of backfill of the soil nail wall, the order of conservatism is identical except that the places of Geoguide 7 (CDR=0.66, 0.72) and FHWA (CDR=0.73, 0.72) are changed. However, the results obtained among U.S. FHWA (2015) and Clouterre (1991) and Geoguide 7 (2008) are not so different.