• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.308-312
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• 2022

3D printing technology, which creates a physical object by various material deposition, has been widely used in recent years in the manufacturing field because of its advantages. Among the various printing technologies, droplet-based 3D printing technology (e.g., Polyjet^®) enables a high-resolution printing using photocurable materials such as hydrogels. Depending on the degree of light exposure, ejected photocurable droplets may have different properties (e.g., viscosity) until they collide with the substrate and it leads to the different spreading behaviors of the droplets (i.e., impact, spreading, and recoiling) during deposition on the substrate. In this study, experimental observation and analysis of the changes in hydrogel droplet viscosity and spreading behavior according to the light exposure were carried out based on high-speed image processing.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.79-86
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• 2021

Purpose : This study was conducted to provide fundamental data to prepare for countermeasure to protect health of workers in the dental clinics from hazardous chemical substance, and to assess effecting factors on management of Material Safety Date Sheet(MSDS) and handling of hazardous chemical substance among workers in dental clinics. Methods : This study was carried out a survey with structured self-administered questionnaire which was consisted of 7 questions about the management of MSDS, 9 questions about recognition and practice of hazardous chemical substances in dental clinics, and 7 questions about general characteristics. Total subjects of this study were 204 adult who workers in dental clinics located in Busan and Gyeng-nam province area. The collected data were analysed using the SPSS statistical package program (ver. 23.0). Results : The factor that positively affected factor on recognition and practice of hazardous chemical substances in dental clinics has experience that has been institutional health-care accreditation. The factor that positively affected the management of MSDS has experience that has been institutional health-care accreditation. Conclusion : It is necessary to prepare countermeasures such as campaign and education on cognition of general chemical substances, and also the author concern that it should be perform the education on handling of hazardous chemical substances in dental clinics for more effecting management of MSDS. In order to improve the management of MSDS and improve the awareness and safety of chemicals, it is necessary to encourage the implementation of the institutional health-care accreditation system or prepare guidelines for the management of MSDS.

• The Journal of Internal Korean Medicine
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• v.42 no.6
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• pp.1255-1268
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• 2021

Objectives: This study aimed to analyze the healthcare utilization behavior of patients visiting the department of Korean internal medicine in the Korean medicine hospital of Wonkwang University in Jeon-ju from July 2018 to June 2021. Methods: We retrospectively analyzed the medical records of 26,108 patients and sorted the data by period, month, visiting types, new or returning types, sex, and age group. IBM SPSS 26.0 and the R 4.05 'changepoint' package were used with various statistical methods, such as Independent t-test, Mann-Whitney test, Chi-square test, Simple regression analysis. The P-value was set at 0.05. Results and Conclusions: Females outnumbered males regardless of period, and the ratio of females fell after COVID-19. Regardless of visiting types, patients in their 50s, 60s, and 70s outrated any other age group. The average number of females among the returning patients decreased significantly after COVID-19, but did not in males. Outpatients under 10 and in their 10s decreased significantly after COVID-19, as did inpatients in their 40s and 60s. The average duration of hospitalization was extended significantly after COVID-19. The number of outpatients and inpatients decreased as time passed after COVID-19. We expect that the results of this study will be used as reference materials in analyzing the effects of COVID-19 on healthcare utilization.

• Earthquakes and Structures
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• v.23 no.6
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• pp.493-502
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• 2022

In recent decades, infrastructural development has exploded, particularly in the coastal region of Saudi Arabia. The rising demand of most consumed aggregate in construction can be effectively compensated by the alternative material like scoria which lavishly exists in the western region. Scoria is characterized as lightweight aggregate beneficially used to develop lightweight concrete (LWC) - a potential alternative of normal weight concrete (NWC) ensuring reduction in the structural element's size, increase in building height, comparatively lighter foundation, etc. Hence, the goal of this study is to incorporate scoria-based structural lightweight concrete and evaluate its impact on superstructure and foundation design beside contributing to the economy of construction. Fresh, mechanical, and rheological properties of the novel LWC have been investigated. The structural analyses employ the NWC as well as LWC based structures under seismic and wind loadings. The commercial finite element package - ETABS was employed to find out the change in structural responses and foundations. The cost estimation and SWOT analysis for superstructure and foundation have also been carried out. It was revealed that the developed LWC enabled a more flexible structural design. Notable reduction in the steel and concrete prices of LWC might be possible in the low-rise building. It is postulated that the cost-effective and eco-friendly LWC will promote the usage of scoria as an effective alternative in Saudi Arabia and GCC countries for structurally viable LWC construction.

• The Journal of Internal Korean Medicine
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• v.44 no.1
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• pp.35-52
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• 2023

Objective: Internal injuries and consumptive disease have different causes, yet they can affect each other. The relationship and combination of prescription drugs in the clinical practice of internal injuries and consumptive disease were analyzed for various diseases of "Donguibogam" through network analysis. Methods: The prescriptions used in consumptive disease and internal injury were established by conducting a full survey on the papers extracted from Donguibogam. The R version 4.0.3 (2020-10-10) and the igraph and arules package were used to perform network analysis and association rule relationship mining analysis in the first and second prescription compositions. Results: The herb frequently used for internal injury was Glycyrrhizae Radix, while the herb combination frequently used was Citri Pericarpium-Glycyrrhizae Radix. For centrality, the main factor was generally Glycyrrhizae Radix. In the case of consumptive disease, the herb most frequently used was Angelicae Gigantis Radix, and the combination most frequently used was Rehmanniae Radix Preparata-Angelicae Gigantis Radix. In terms of centrality, it was Angelicae Gigantis Radix. As a result of the network analysis of herbal prescription frequency, each group was divided into three. Conclusion: The interrelationship between internal injury and consumptive disease prescription drugs may reveal the differences and similarities between internal injury and consumptive disease and may serve as a basis for the development of new drugs or materials that can enhance mutual effectiveness in the treatment of internal injury and consumptive diseases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.6
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• pp.356-362
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• 2022

Objectives: A single-blinded randomized controlled trial was designed to compare and evaluate the effectiveness of the periotome and piezotome as aids for atraumatic extraction and its sequalae. Materials and Methods: The study sample comprised 48 teeth, equally allotted to the piezotome or periotome groups by random allocation, in participants aged 19-62 years. All samples in both groups had either complete tooth structure or intact roots without crowns and had mobility ≤grade II. Clinical parameters of operative duration, presence or absence of gingival laceration, reported operative and postoperative pain, and intake of analgesics following extraction were recorded. IBM SPSS software package version 22 was used for data entry and analysis. Results: The mean operation time was significantly (P≤0.05) longer in the piezotome group than in the periotome group. However, fewer gingival lacerations were observed with use of a piezotome than with a periotome, although no significant difference was observed. The piezotome group reported significantly (P≤0.05) higher visual analog scale (VAS) pain scores during the procedure and non-significantly higher scores thereafter until the third postoperative day. In the piezotome group, the dosage of analgesic was higher, although the periotome group had a higher percentage of participants who used analgesics postoperatively; however, these differences were not statistically significant. Conclusion: The present clinical trial favors the use of periotome over piezotome for atraumatic extraction due to shorter operating time, lower postoperative VAS pain scores, and lower dosage of analgesics despite the superior ability of the piezotome to prevent gingival laceration.

• Journal of the Korean Society of Food Culture
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• v.24 no.3
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• pp.267-278
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• 2009

The purpose of this study was to examine parents' perceptions towards, and the importance and performance levels of, foodservices in child-care centers and to suggest ways to increase foodservice quality and promote efficient operations in the future. A questionnaire survey was provided to 540 parents and the return rates 82%. The survey period was from June 20 to July 27,2007. The collected data were statistically analyzed with the SAS package program using descriptive statistical analysis, t-tests, ANOVA, Duncan's multiple comparisons, factor analysis, and multiple regression analysis. The results were as follows: The parents perceived that foodservice operations promoted their children's health and helped them form desirable dietary habits. The parents also had a high level of perception toward the need for foodservice, earning greater than 4.5 points out of 5 points. Their perceptions of foodservice quality were examined by four dimensions of importance and performance levels. While the parents gave 4 points or greater of 5 points to most quality attributes of importance level, they gave 4 points of less out of 5 points to most quality attributes of performance level. As for the importance and performance levels of the quality dimensions of meal service, the parents regarded sanitation as the most important dimension. IPA showed that 'organic food materials' was included as a 'focus here' area. The overall satisfaction level for foodservice was 3.59 out of 5 points. A higher level of satisfaction was shown when a dietitian was present as well as in public childcare centers. According to multiple regression analysis, 53.51% of the variance in the respondents' overall satisfaction scores was explained by factors such as food, sanitation, environment, and foodservice effects.

• Journal of the Korean Society of Food Culture
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• v.24 no.6
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• pp.778-783
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• 2009

The purpose of this study was to determine the basic materials needed for nutrition and health programs for aged people. In order to set up these programs, the nutritional habit, nutritional knowledge and functional health status (mobility, functional assessment, and falls efficacy) of the aged were measured, and their relationships were determined. Data was collected on 57 aged individuals that participated in the 'Exercise Program for the Aged' conducted by the National Health Insurance Corporation. These 57 subjects were interviewed and tested by direct measurement prior to conducting the program. The data was analyzed using the SPSS 13.0 Package. According to the results, the nutritional habit ranged from 24-50 out of 50, and the average was 37.2, which was above the middle level. The average nutritional knowledge was of 4.02 out of 5, which was considered reasonably high. Especially, more than half of these subjects were uneducated, but they had a high interest in nutrition. The average mobility was determined to be 9.2 seconds and the falls efficacy was 64.2 out of 100. In addition, subjects answered that they had a fear of falling due to low confidence, which indicates that safety education for the prevention of falls should be provided to aged individuals in the future. The results showed that notable counter-relations between nutritional habit and functional health status existed.

• Safety and Health at Work
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• v.14 no.3
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• pp.287-294
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• 2023

Background: Fruit and vegetable market is an abundant source of bioaerosols. Exposure to organic and inorganic waste and long-term inhalation of bioaerosols during working hours leads to chronic respiratory symptoms. Hence, this study aimed to determine the prevalence of chronic respiratory symptoms and related factors among fruit and vegetable workers compared with the control group in Addis Ababa, Ethiopia. Methods and materials: A comparative cross-sectional study was conducted from 2020 to 2021. Data were entered in EpiData 3.1 and exported to Statistical Package for the Social Sciences (SPSS) version 25. Logistic regressions were computed to depict the data and related factors. The culture method was done to count and compare bacterial and fungal concentrations between fruit and vegetable workers and office workers. Results: In this study, the prevalence of chronic respiratory symptoms (PR = 2.87, 95% confidence interval [CI]: 1.772-4.66) was significantly higher among fruit and vegetable workers (46.7%) than controls (23.4%). Sex (adjusted odds ratio [AOR] = 2.11, 95% CI = 1.12-3.98), educational status (AOR = 1.34, 95% CI = 0.78-2.32), working hours per day (AOR = 3.91, 95% CI = 1.586-9.65), and working department (AOR = 3.20, 95% CI = 0.90-11.40) were associated with chronic respiratory symptoms. Bacterial and fungal concentrations were significantly higher in the air of the vegetable market (276 colony-forming unit) than the air in the workplace of controls (7 colony-forming unit). Conclusion: The fruit and vegetable market workers (greengrocers) had a higher prevalence of chronic respiratory symptoms relative to office workers. Respiratory protective devices should be given to deliver preventive measures.

• Restorative Dentistry and Endodontics
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• v.48 no.3
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• pp.25.1-25.13
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• 2023

Objectives: The purpose of this study was to evaluate the influence of endodontic access cavities design on the removal of calcium hydroxide medication of the apical third of mandibular incisor root canal walls and dentinal tubules with different cleaning protocols: EDDY sonic activation, Er,Cr:YSGG laser-activated irrigation, or conventional irrigation with IrriFlex. Materials and Methods: Seventy-eight extracted human mandibular incisors were assigned to 6 experimental groups (n = 13) according to the endodontic access cavity and cleaning protocol for calcium hydroxide removal: traditional access cavity (TradAC)/EDDY; ultraconservative access cavity performed in the incisal edge (UltraAC.Inc)/EDDY; TradAC/Er,Cr:YSGG; UltraAC. Inc/Er,Cr:YSGG; TradAC/IrriFlex; or UltraAC.Inc/IrriFlex. Confocal laser scanning microscopy images were used to measure the non-penetration percentage, maximum residual calcium hydroxide penetration depth, and penetration area at 2 and 4 mm from the apex. Data were statistically analyzed using Shapiro-Wilk and WRS2 package for 2-way comparison of non-normally distributed parameters (depth of penetration, area of penetration, and percentage of non-penetration) according to cavity and cleaning protocol with the significance level set at 5%. Results: The effect of cavity and cleaning protocol interactions on penetration depth, penetration area and non-penetration percentage was not found statistically significant at 2 and 4 mm levels (p > 0.05). Conclusions: The present study demonstrated that TradAC or UltraAC.Inc preparations with different cleaning protocols in extracted mandibular incisors did not influence the remaining calcium hydroxide at 2 and 4 mm from the apex.