• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
• /
• pp.521-524
• /
• 2003

In recent, there have been several developments in lamp technology that promise savings in electrical power consumption and improved quality of the lighting space. Above all, the advantage of ring-shaped electrodeless fluorescent lamp is the removal of internal electrodes and heating filaments that are a light-limiting factor of conventional fluorescent lamps. The ring-shaped electrodeless lamp is intended as a high efficacy replacement for the incandescent reflector lamp in many applications. Therefore, the life time of ring-shaped electrodeless fluorescent lamps is substantially higher than that of conventional fluorescent lamps and last up to 60,000 hours. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250kHz and some specific conditions.

• 한국식품영양학회지
• /
• 제32권2호
• /
• pp.133-137
• /
• 2019

Curcumin is a hydrophobic polyphenol extracted from turmeric that exhibits a variety of biological functions has albeit with limited efficacy as a functional food material owing to its low absorption when administered orally. The newly developed curcumin powder formulation exhibits improved absorption rate in vivo. This study evaluates the anti-oxidant effects of $Theracurmin^{(R)}$ (TC), which is highly bio-available in curcumin powder. The antioxidant activity of TC was investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferrous reducing antioxidant power (FRAP) assays, NO radical, superoxide radical, $H_2O_2$ scavenging activity, and total antioxidant capacity (TAC). Additionally, we evaluated the antioxidant activity of TC in high-fat diet (HFD)-fed streptozotocin (STZ)-induced Type 2 diabetic rats. As a result of oral administration of TC for 13 weeks in type 2 diabetic rats, the group administration of 2,000 mg/kg significantly increased FRAP, superoxide dismutase (SOD), and reduced the level of glutathione (GSH) in liver tissue 1.9, 1.2, and 1.2-times, respectively. Furthermore, serum TAC levels increased by 1.3-fold after the rats were administered with a dose of 500 mg/kg. These results were consistent with the in vitro assay results. In conclusion, TC exhibited its potential as a functional food material through its antioxidant properties.

• 한국치위생학회지
• /
• 제19권2호
• /
• pp.231-239
• /
• 2019

Objectives: This study was conducted to understand the influencing factors of job satisfaction of clinical dental hygienists in schoolwork, and use the basic data to enhance their job satisfaction. Methods: A self-reported questionnaire was filled out by 210 dental clinic hygienists from June 10 to August 30 of 2018. Data were analyzed using SPSS 22.0. Independent t-test, one-way ANOVA, Scheffe's post-hoc test, and Pearson correlation coefficient were reviewed, and a multiple regression analysis was conducted. Results: The scores of subjects' professional self-concept, self-esteem, job stress, and job satisfaction were 3.37, 3.80, 2.79, and 3.37, respectively. The influencing factors of job satisfaction of clinical dental hygienists in schoolwork included marital status, support in workplace, professional self-concept, and job stress, with 41.6% of the explanatory power. Conclusions: The stronger the professional self-concept, the lower the job-stress and higher the job satisfaction. The job satisfaction was also higher in the group in which the subjects were married and getting support in the workplace compared to the other group with no support in the workplace. Therefore, support systems and institutional support are required for clinical dental hygienists to be continuously educated in the workplace.

• Communications for Statistical Applications and Methods
• /
• 제27권6호
• /
• pp.701-714
• /
• 2020

Quantitative high throughput screening (qHTS) assays are used to assess toxicity for many chemicals in a short period by collectively analyzing them at several concentrations. Data are routinely analyzed using nonlinear regression models; however, we propose a new method to analyze qHTS data using a nonlinear mixed effects model. qHTS data are generated by repeating the same experiment several times for each chemical; therefor, they can be viewed as if they are repeated measures data and hence analyzed using a nonlinear mixed effects model which accounts for both intra- and inter-individual variabilities. Furthermore, we apply a one-step approach incorporating robust estimation methods to estimate fixed effect parameters and the variance-covariance structure since outliers or influential observations are not uncommon in qHTS data. The toxicity of chemicals from a qHTS assay is classified based on the significance of a parameter related to the efficacy of the chemicals using the proposed method. We evaluate the performance of the proposed method in terms of power and false discovery rate using simulation studies comparing with one existing method. The proposed method is illustrated using a dataset obtained from the National Toxicology Program.

• 임상간호연구
• /
• 제28권1호
• /
• pp.66-75
• /
• 2022

Purpose: The purpose of this study is to identify the factors influencing the intention to report child abuse of emergency room nurses based on the health belief model. Methods: This was a descriptive study that used a cross-sectional design. A total of 188 emergency room nurses working at general hospitals with more than 300 beds in Seoul participated in the study. Data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and multiple regression analysis with the SPSS 25.0 program. Results: Correlations and regression analyses showed that the perceived severity (β=.14, p=.024), perceived barrier (β=-.25, p<.001), and self-efficacy (β=.31, p<.001) were factors influencing emergency room nurses' intention to report child abuse, and the explanatory power of the model was 33.0%. Conclusion: The results of this study related to the health belief model, being a valid theoretical basis for child abuse reporting intention research, significantly suggest new research directions in the future. In addition, to increase the nurses' intention to report child abuse in the emergency room, the influencing factors identified in this study can be utilized and develop specific interventions using the health belief model.

• 가정∙방문간호학회지
• /
• 제29권1호
• /
• pp.82-92
• /
• 2022

Purpose: The purpose of this study was to investigate the factors affecting the prevention behavior of COVID-19 infection among nursing students. Methods: This survey was conducted from September 3 to October 2, 2021 among 172 sophomore and senior students at universities in D metropolitan city and J province. The data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation and Hierarchical Regression. Results: There were significant differences in COVID-19 preventive behavior by gender (t=0.13, p=.017) and clinical practice experience (t=2.78, p=.006). COVID-19 preventive behavior showed significantly positive correlations with subjective norm (r=.35, p<.001), self-efficacy(r=.33, p<.001), and intention(r=.62, p<.001). The variables affecting COVID-19 preventive behavior were intention(β=.529, p<.001), subjective norm(β=.169, p=.008), and clinical practice experience(β=.118, p=.049), and the explanatory power was 43%. Conclusion: Considering these results, it is necessary to develop strategies that can encourage the intention of nursing students to practice prevention for COVID-19 infection control. In addition, maintaining subjective norms through national policies is a critical strategy.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제44권2호
• /
• pp.37-43
• /
• 2022

Silkworm food has been found to be effective for dementia, liver function, lowering blood sugar, and possesses antioxidant properties, which has been attracting attention as a health functional food. In this study, methods for enhancing the functionality of silkworms were explored and the production potential of high-functional silkworms was analyzed. For enhancing antioxidant activity, ascorbic acid, caffeic acid, laminarin, and glutathione were injected or fed to 5th instar silkworms, and the antioxidant activity of silkworm extract was comparatively analyzed. There was no significant change in polyphenol and flavonoid content, but it was confirmed that 2,2-diphenyl-1-picrylhydrazyl radical scavenging ability, superoxide dismutase-like activity, and reducing power were slightly increased after injection of ascorbic acid, caffeic acid, and glutathione. To confirm the increase in antioxidant efficacy through feeding, an inducer was mixed with sucrose and sprayed on mulberry leaves. As a result, the growth rate of silkworms improved and all indicators of antioxidant activity were improved in silkworms fed with ascorbic acid and glutathione. Considering these results, producing high-functional silkworms was deemed possible.

• Nuclear Engineering and Technology
• /
• 제54권9호
• /
• pp.3380-3389
• /
• 2022

We evaluated the performance of an improved hybrid median filter (IHMF) applied to X-ray computed tomography (CT) images obtained using a high-resolution photon-counting cadmium zinc telluride (CZT) detector. To study how the proposed approach improves the image quality, we measured the noise levels and the overall CT-image quality. We established a CZT imaging system with a detector length of 5.12 cm and thickness of 0.3 cm and acquired phantom images. To evaluate the efficacy of the proposed filter, we first modeled two conventional median filters. Subsequently, we were able to achieve a normalized noise power spectrum result of ~10^-8 mm², and furthermore, the proposed method improved the contrast-to-noise ratio by a factor of ~1.51 and the coefficient of variation by 1.55 relative to the counterpart values of the no-filter image. In addition, the IHMF exhibited the best performance among the three filters considered as regards the peak signal-to-noise ratio and no-reference-based image-quality evaluation parameters. Thus, our results demonstrate that the IHMF approach provides a superior image performance over conventional median filtering methods when applied to actual CZT X-ray CT images.

• 공업화학
• /
• 제33권4호
• /
• pp.352-366
• /
• 2022

Nuclear power plant operations for electricity generation, rare-earth mining, nuclear medical research, and nuclear weapons reprocessing considerably increase radioactive waste, necessitating massive efforts to eradicate radioactive waste from aquatic environments. Cobalt (⁵⁸Co) and strontium (⁹⁰Sr) radioactive elements have been extensively employed in energy generation, nuclear weapon testing, and the manufacture of healthcare products. The erroneous discharge of these elements as pollutants into the aquatic system, radiation emissions, and long-term disposal is extremely detrimental to humans and aquatic biota. Numerous methods for treating radioactive waste-contaminated water have emerged, among which the adsorption process has been promoted for its efficacy in eliminating radioactive waste from aquatic habitats. The current review discusses the adsorptive removal of radioactive waste from aqueous solutions using low-cost adsorbents, such as graphene oxide, metal-organic frameworks, and inorganic metal oxides, as well as their composites. The chemical modification of adsorbents to increase their removal efficiency is also discussed. Finally, the current state of ⁵⁸Co and ⁹⁰Sr removal performances is summarized and the efficiencies of various adsorbents are compared.

• 한국기계가공학회지
• /
• 제21권5호
• /
• pp.91-97
• /
• 2022

The Directed Energy Deposition (DED) is a representative metal additive manufacturing method. Owing to its strong point of repairment, its application is gradually spreading in aerospace applications, power generation, military components, and mold making. 5-axis cladding is needed to repair damage, such as wear and scratches on cylindrical surfaces to circular-shaped parts, including sleeves and liners. Furthermore, the condition of cladding on inclined parts must also be considered to prevent interference between the nozzle and the part. In this study, the effects of changes in scanning speed due to the 5-axis control system and differences from the height of laser beam irradiation due to inclination are evaluated among the items that should be additionally considered in 5-axis cladding compared to 3-axis cladding. Moreover, the trends of the width and height of the clad are identified by different tilting angles via single line cladding. Lastly, cladding methods on cylindrical surfaces at various angles are proposed to enhance the clad quality and post-processing efficacy. These results can be applied with 5-axis cladding on inclined surfaces, including cylindrical surfaces.