• Journal of the Korean Geotechnical Society
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• v.38 no.5
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• pp.5-17
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• 2022

A pile is a type of medium for constructing superstructures in weak geotechnical conditions. A pretensioned spun high-strength concrete (PHC) pile is composed of high-strength concrete with a specified strength greater than 80 MPa. Therefore, it has advantages in resistance to axial and bending moments and quality control and management since it is manufactured in a factory. However, the skin friction of a pile, which accounts for a large portion of the pile bearing capacity, is only approximated using empirical equations or standard penetration test (SPT) N-values. Particularly, there are some poor research results on the pile-soil interface under the seismic loads in Korea. Additionally, some studies do not consider geoenvironmental elements, such as groundwater pH values. This study performs sets of cyclic simple shear tests using submerged concrete specimens for 1 month to consider pH values of groundwater and clay specimens composed of kaolinite to generate a pile-soil interface. 0.2 and 0.4 MPa of normal stress conditions are considered in the case of pH values. The disturbed state concept is employed to express the dynamic behavior of the interface, and the disturbed function parameters are newly suggested. Consequently, the largest disturbance increase under basic conditions is observed, and an early approach to the failure under low normal stress conditions is presented. The disturbance function parameters are also suggested to express this disposition quantitatively.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.2
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• pp.164-177
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• 2022

Medical device usability evaluation refers to the evaluation of medical devices through actual users before the final prototype production is completed. IEC 62366, one of the international safety standards for electronic medical devices, is a standard that must be applied to obtain medical device licenses in major advanced countries such as Europe and the United States. In Korea, through the Ministry of Food and Drug Safety's notice, from January 2021, sequential application by grade has been implemented. In this study, 15 participant specialists were recruited through the Incheon G University Hospital Medical Device Convergence Center for formative evaluation during user suitability evaluation of the focused ultrasound stimulation system being developed by Icleo Co., Ltd., and the test was conducted through joint scenario development. . In the result of task performance, the performance rate was 90.67%, and after the completion of the performance, 86.67% of 'Easy user interface' and 94% of 'Identification/Readability/Understanding of information' questions in the participant survey results analysis by question. The response rate was above average.

• The Journal of Korean Medicine
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• v.43 no.1
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• pp.6-17
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• 2022

Objectives: This study describes the implementation of a training course that aimed to increase the competency of undergraduate students of Korean medicine at a single college to obtain informed consent and perform bee venom acupuncture using an objective structured clinical examination (OSCE). Methods: We developed and implemented a short training course for 111 fourth-year students of Korean medicine during their clinical rotation at the Department of Acupuncture and Moxibustion Medicine. Lectures were conducted on the effects of and hypersensitivity reactions to bee venom acupuncture, obtaining informed consent, performing skin test and bee venom acupuncture. Due to the COVID-19 pandemic, some students were offered online lectures, and some could not experience the performance of OSCE in person. A survey with 16 closed and three open questions was used to investigate self-efficacy, opinions about the online lectures, and the OSCE. Results: Out of 111 questionnaires, 104 were completed (94%). Students were generally satisfied with the online lectures and OSCE. For the subjective questionnaire about what was helpful in the training of bee venom acupuncture techniques and OSCE, the authenticity of the teaching method was recorded the highest. Conclusions: This study showed that online lectures were effective in teaching clinical skills of Korean Medicine. It is necessary to produce standard educational materials for clinical skills of Korean Medicine, and studies to analyze the reliability and validity of OSCE are needed.

• Journal of the Korean Geotechnical Society
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• v.37 no.11
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• pp.93-105
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• 2021

In this study, we evaluated the effect of soil fine contents on the formation of underground cavities and ground cave-ins induced by damaged sewer pipes. Simulating the domestic rainfall conditions and ground conditions, model tests were performed under three different fine particle contents conditions (7.5%, 15%, and 25%). By repeating the groundwater supply and drainage twice, ground settlement and the amount of discharged soil were obtained. Also, digital images were taken at regular time intervals during the model tests, and internal displacement and deformation were measured using PIV technique. As the cycles were repeated, the soil with high fine content showed greater resistance to the formation of underground cavities. The ground cave-ins, identified by the collapse of the surface, occurred only when the fine particle content was 15%. It is presumed to be due to the suffusion phenomenon; further study was needed to investigate the effect of fine particle contents on the suffusion phenomenon and associated changes of soil strength.

• Journal of the Korea Institute of Building Construction
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• v.22 no.1
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• pp.23-34
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• 2022

The purpose of this study is to evaluate the adhesion properties of polymer cement composites for crack repair of an RC structure. Polymer cement composites are manufactured from cement, three types of polymers and silica fume, and the mixture is designed by adjusting the water cement ratio and AE reducing agent so that the viscosity target of the polymer cement composites is 700mPa·s or less. According to the test results, the Type-A adhesion in tension of the polymer cement composite exceeded the adhesion standard of 1.0MPa of the polymer finishing material, and furthermore, depending on the type of polymer, the adhesion in tension was highest for SAE, followed in descending order by EVA, and SBR. In addition, the adhesion in tension of Type-B is up to 1/4.5 lower than that of Type-A, but the incorporation of silica fume shows a significant improvement in terms of adhesion in tension. Based on this study, the basic mixing design of the polymer cement composites required for viscosity and adhesive performance required for crack repair of the RC structure was completed. It could be proposed as an optimal mixing design under conditions for intermixing polymer type EVA, SAE, and P/C 80%-100%.

• Nutrition Research and Practice
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• v.16 no.5
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• pp.646-657
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• 2022

BACKGROUND/OBJECTIVES: The doubly labeled water (DLW) method is the gold standard for estimating total energy expenditure (TEE) and is also useful for verifying the validities of dietary evaluation tools. In this study, we compared the accuracy of total energy intakes (TEI) estimated by the 24-h diet recall method with TEE obtained using the doubly labeled water method. SUBJECTS/METHODS: This study involved 71 subjects aged 20-49 yrs. Over a 14-day period, three 24-h diet recalls per subject (2 weekdays and 1 weekend day) were used to estimate energy intakes, while TEE was measured using the DLW method. The paired t-test was used to determine the significance of differences between TEI and TEE results, and the accuracy of the 24-h recall method was determined by accuracy predictions percentage, root mean square error, and bias. RESULTS: Average study subject age was 33.4 ± 8.6 yrs. The association between TEI and TEE was positive and significant (r = 0.463, P < 0.001), and the difference between TEI (2,084.3 ± 684.2 kcal/day) and TEE (2,401.7 ± 480.3 kcal/day) was also significant (P < 0.001). In all study subjects, mean TEI was 12.0% (307.5 ± 629.3 kcal/day) less than mean TEE, and 12.2% (349.4 ± 632.5 kcal/day) less in men and 11.8% (266.7 ± 632.5 kcal/day) less in women. Rates of TEI underprediction for all study subjects, men, and women, were 60.5%, 51.4%, and 66.7%, respectively. CONCLUSIONS: This study shows that 24-h diet recall underreports energy intakes. More research is needed to corroborate our findings and evaluate the accuracy of 24-h recall with respect to additional demographics.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.710-718
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• 2023

Purpose: The purpose of this study is to objectify the analysis results using the disaster safety awareness survey for high school students, which has been systematically and continuously educated since the Ferry Sewol disaster, and to promote educational effects by identifying the educational status. Method: The 12 questions of the disaster safety awareness survey were answered using the direct entry method on a Likert 5-point scale, and the SPSS 24 and varimax (orthogonal rotation) methods were used to establish and test research hypotheses. Result: As a result of the verification, it was found that the independent variables, knowledge competency and attitude competency, had a positive effect on the dependent variable, behavioral competency, and there was no multicollinearity, so it was verified that it was meaningful. Conclusion: As a result of the survey analysis, domestic disaster safety education showed a significant impact on the level of disaster safety awareness as an education that meets its goals. Various aspects of disasters show that the educational effect can be improved only when education is established as education by life cycle.

• Journal of Oriental Neuropsychiatry
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• v.34 no.3
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• pp.125-139
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• 2023

Objectives: This was a preliminary study to re-verify the reliability and validity of the Core Seven Emotions Inventory-Short Form (CSEI-s) and to establish standards for an objective scoring system such as T-scores and percentile for the normative group. Methods: Subjects were sampled through population-proportional regional allocation based on adults aged 20 or older and 65 or younger who voluntarily consented. Reliability was analyzed by performing an internal consistency (Cronbach's α) test and calculating means and standard deviations for each scale. The validity was analyzed between the CSEI-s and STAXI-K, SADS, COMOSWB, HADS, K-PANAS, Core emotions VAS. Results: The CSEI-s revealed notable gender discrepancies in aspects such as thought (思), fear (恐), and fright (驚), with women generally scoring higher than men. CSEI-s scores showed statistically significant differences in joy (喜) and thought (思) between those in their 20s and those in their 50s and 60s. As a result of the validity analysis, the seven-factor configuration was found to be statistically valid, and as a result of the correlation analysis with the coexistence scale, the correlation between each emotion and the seven emotions was found to be statistically significant. Cronbach's α for the CSEI-s was .891, showing statistically significant reliability. Conclusions: A preliminary study was conducted to standardize the shortened form of the Core Emotion Scale, and the reliability and validity were confirmed. A main survey of more people should be conducted in the future. Future results can contribute to revitalizing the development of oriental medicine evaluation tools and establishing an evidence base by standardizing the CSEI-s.

• Journal of the Korea Institute of Building Construction
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• v.23 no.2
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• pp.153-164
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• 2023

The objective of this study is to examine the removal rate of air pollutants, specifically sulfur oxides (SO_x) and nitrogen oxides(NO_x), using concrete permeable blocks containing zeolite beads coated with materials capable of eliminating these pollutants. Titanium dioxide(TiO₂) powder and coconut shell powder were utilized for the removal of SO_x and NO_x and were applied as coatings on the zeolite beads. Concrete permeable block specimens embedded with the coated zeolite beads were produced using an actual factory production line. Test results demonstrated that the concrete permeable block containing zeolite beads coated with coconut shell powder in the surface layer achieved SO_x and NO_x removal rates of 12.5% and 99%, respectively, exhibiting superior performance compared to other blocks. Additionally, the flexural strength and slip resistance were 5.3MPa and 65BPN or higher, respectively, satisfying the requirements specified in KS F 4419 and KS F 4561. Conversely, the permeability coefficient exhibited low permeability, with grades 2 and 3 before and after contaminant pollution, according to the standard for 'design, construction, and maintenance of pavement using permeable block'. In conclusion, incorporating zeolite beads coated with coconut shell powder in the surface layer enables simultaneous removal of SO_x and NO_x, irrespective of ultraviolet rays, while maintaining adequate flexural strength and slip resistance. However, the permeability is significantly reduced, necessitating further improvements.

• Journal of the Korean Recycled Construction Resources Institute
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• v.11 no.1
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• pp.55-61
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• 2023

This study aims to develop CLSM fill material for emergency restoration using landfill coal ash. As a result of examining physical properties such as particle size distribution and fines content of landfill coal ash, bottom ash, fly ash, and general soil were mixed, and SP was found to have a density of 2.03 and a residual particle pass rate of 7.8 %. CLSM materials that secure fluidity in unit quantities without using chemical admixtures such as glidants and water reducing agents have a high risk of material separation due to bleeding. As a result of this experiment, it was found that the bleeding ratio did not satisfy the standard in the case of the specimen with a large amount of fly ash and a lot of addition of mixing water. As a result of the compressive strength test, the strength development of 0.5 MPa or more for 4 hours was found to be satisfactory for the specimens using hemihydrate gypsum with a unit binder amount of 200 or more, and the remaining gypsum showed poor strength development. Although it is judged that landfill coal ash can be used as a CLSM material, it is necessary to identify and apply the physical and chemical characteristics of coal ash buried in the ash treatment plant of each power generation company.