• Applied Chemistry for Engineering
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• v.34 no.2
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• pp.180-185
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• 2023

To improve the efficiency of water electrolysis, it is essential to develop an oxygen evolution reaction (OER) electrocatalyst with high performance and long-term stability, accelerating the reaction rate of OER. In this study, a hollow metal-organic framework (MOF)-derived ruthenium-cobalt oxide catalyst was developed to synthesize an efficient OER electrocatalyst. As the synthesized catalyst increases the surface exposure of ruthenium, a low overpotential (386 mV) was observed at a current density of 10 mA/cm² with a low Tafel slope. It is expected to be able to replace noble metal catalysts by showing higher mass activity and stability than commercial RuO₂ catalysts.

• Journal of the Institute of Convergence Signal Processing
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• v.23 no.4
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• pp.216-221
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• 2022

The 4th industrial revolution is accelerating the transition to digital innovation in various aspects of our daily lives, and efforts for manufacturing innovation are continuing in the manufacturing industry, such as smart factories. The 4th industrial revolution technology in manufacturing can be used based on AI, big data, IoT, cloud, and robots. Through this, it is required to develop a technology to establish a production facility data collection and analysis system that has evolved from the existing automation and to find the cause of defects and minimize the defect rate. In this paper, we implemented a system that collects power, environment, and status data from production facility sites through IoT devices, quantifies them in real-time in a cloud computing environment, and displays them in the form of MQTT-based real-time infographics using widgets. The real-time sensor data transmitted from the IoT device is stored to the cloud server through a Rest API method. In addition, the administrator could remotely monitor the data on the dashboard and analyze it hourly and daily.

• Journal of dental hygiene science
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• v.23 no.2
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• pp.88-92
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• 2023

Background: Aphthous stomatitis is a common disease of the oral mucosa and its pathogenesis is associated with several risk factors. Frequently, minor ulcers are idiopathic in nature and often resolve naturally. However, those ulcers are painful and sensibly compromise patients' eating. There are different treatment strategies for the clinical management of oral aphthae. Methods: The present study assessed the efficacy of a film-forming cream in accelerating the healing and diminishing the pain associated with minor aphthae in a randomized fashion design. The test product (AphtoFix^®) was compared with placebo cream in a cohort of patients with a diagnosis of minor recurrent stomatitis. Patients were randomly distributed into two groups and were followed for 10 days. The primary outcomes included the number of days until symptoms were relieved and the number of days to complete healing. Results: Thirty-six patients completed the follow-up, eighteen per group. All lesions eventually healed within day 10. However, patients in the test group experienced significantly less pain, already from day 1. Patients in the test group also showed a faster healing rate of the lesion with an average of 7 days against the 9 days required for patients in the control group. Conclusion: The present study supported the utility of a film-forming in cream in relieving the patient from symptoms associated with aphthous stomatitis already at day 1 of product use. Patients also displayed faster healing of the lesions when compared to the control group. Further studies with greater sample size and patient stratification according to age and risk factors are recommended to support the present findings.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.330-342
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• 2023

Background: As the medical knowledge base grows at an accelerating rate, evidence-based clinical performance becomes increasingly important for providing quality care. Previous studies have highlighted the need to promote job crafting to actualize evidence-based practical skills in the medical field. This study aimed to investigate the degree of evidence-based practice among dental hygienists and assess the impact of job crafting on the evidence-based practical skills of dental hygienists. Methods: Dental hygienists working at dental hospitals and clinics in Seoul and Gyeonggi Province were surveyed between February 28 and April 6, 2023. The sample was comprised of 267 participants. The hypotheses were tested independent t-tests, one-way analysis of variance, Pearson's correlation coefficients, and multiple regression analyses using SPSS 29.0. Results: The degree of job crafting by dental hygienists demonstrated significant differences based on educational attainment, workplace size, and workplace type. Evidence-based practical skills exhibited significant variations based on educational attainment and job position. All job crafting subfactors demonstrated positive correlations with evidence-based practical skills. The job crafting subfactors affecting the evidence-based practical skills of dental hygienists were 'increasing structural job resources' and 'increasing challenging job demands,' which together explained 38.7% of the variance in evidence-based practical skills. Conclusion: This study demonstrates that job crafting was positively and significantly correlated with evidence-based practical skills. To strengthen the job crafting ability of dental hygienists, improving environmental conditions and fostering an organizational culture that motivates continued participation in education is necessary. The development and promotion of programs that enable learning of the latest evidence should be actively pursued. Additionally, regular attendance at workshops and participation in organizational evidence-based practice education programs are necessary.

• Steel and Composite Structures
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• v.48 no.1
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• pp.59-71
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• 2023

Corrosion of the headed studs shear connectors is an important factor in the reduction of the durability and mechanical properties of the steel-concrete composite structure. In order to study the effect of stud corrosion on the mechanical properties in the negative moment region of steel-concrete composite beams, the corrosion of stud was carried out by accelerating corrosion method with constant current. Static monotonic loading was adopted to evaluate the cracking load, interface slip, mid-span deflection, and ultimate bearing capacity of four composite beams with varying corrosion rates of headed studs. The effect of stud corrosion on the stiffness of the composite beam's hogging moment zone during normal service stage was thoroughly examined. The results indicate that the cracking load decreased by 50% as the corrosion rate of headed studs increase to 10%. Meanwhile, due to the increase of interface slip and mid-span deflection, the bending stiffness dropped significantly with the same load. In comparison to uncorroded specimens, the secant stiffness of specimens with 0.5 times ultimate load was reduced by 25.9%. However, corrosion of shear studs had no obvious effect on ultimate bending capacity. Based on the experimental results and the theory of steel-concrete interface slip, a method was developed to calculate the bending stiffness in the negative bending moment region of composite beams during normal service stage while taking corrosion of headed studs into account. The validity of the calculation method was demonstrated by data analysis.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.158-161
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• 2004

In order for better management of a medical linear accelerator, the records of the operational failures of Varian CL2100C over ten years were analyzed. The failures were classified according to the involved functional subunits and each class was rated into three levels depending on operational conditions. The relationship between the failure rate and working ratio was investigated. Among the recorded failures ( total 587 failures), the most frequent failure, which was 20% of the total. was observed in the parts related to the collimation system including monitor chamber. Regrading to the operational conditions, the 2nd level of failures, that temporally interrupted treatments, was the most frequent. The 3rd level of failures, that interrupted treatment for more than several hours, was mostly caused by the accelerating subunit. The average life-time of a Klystron and Thyratron became shorter as the working ratio increased, which was 42 and 83% of the expected values, respectively. Recording equipment problems and failures in detail over a long period of time can provide a good knowledge of equipment function as well as the capability to forecast future failure. More rigorous equipment maintenance is required for old medical linear accelerator to avoid the serious failure in advance, and improve the patient treatment quality.

• The Korean Journal of Mycology
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• v.14 no.3
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• pp.215-223
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• 1986

Protoplasts of P. cornucopiae were reverted to normal hyphal growth and reversion frequency was $0.04{\sim}19%$. The complete medium stabilized with 0.6 M sucrose was most effective for regeneration of protoplasts. When hypertonic mushroom complete medium not containing agar was overlaid, regeneration frequency of protoplasts was the highest rate among the others of topagar. The protoplast reversion frequency and mycelial growth of P. cornucopiae were increased when various amino acids, nucleic acid components and vitamin compound were added to the hypertonic minimal medium. The relation between sources increasing reversion frequency and sources accelerating mycelial growth was similar in amino acids and nucleic acid components but it was different in vitamins. The protoplast reversion frequency showed the highest rate when all sources were added to the regeneration minimal medium. Microscopically, regeneration patterns of protoplasts showed formation of a bud-like structure, direct germination, yeast-like cell chain of the protoplast, and the production of both direct germ tube and yeast-like cell chain from a protoplast.

• Journal of dental hygiene science
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• v.13 no.4
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• pp.359-368
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• 2013

This study aimed to evaluate conditions and performance of quality improvement (QI) activity in Korean dental hospitals. Twenty one representative dental hospitals in Korea were selected by the selection criteria. A questionnaire was implemented to measure awareness, perceived needs, educations, conferences, works, activating/obstructive factors and satisfaction related to QI activities. Satisfaction score range from 0 (lowest) to 5 (highest) among 329 dental hygienists who worked in the selected 21 dental hospitals. Implementation rate of programs on external customer satisfaction was the highest 59.9% in QI activities, and reduction of expenses (59.4%), Improvement in health care quality (58.7), risk management (52.8) were followed, while improvement in work efficiency (46.5) showed the lowest implementation rate. The most influencing factor accelerating QI activities was 'active participation of hospital workers' (54.7%), and 'effort to improve customer satisfaction' (44.7%) followed. The most influencing QI related obstructive factor was 'lack of QI-related manpower and support' (47.1%). A balanced development including QI programs with lower implementation rates is necessary. Encouraging participation of workers may be the most important in developing dental QI activities further.

• Journal of the Korea Institute of Building Construction
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• v.15 no.3
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• pp.265-271
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• 2015

This study is intended to produce a PC (Precast Concrete) member without a steam curing process in developing the high early strength concrete satisfying the condition of 10MPa in compressive strength at the age of 6 hours, and is intended to ensure economic feasibility by increasing the turnover rate of concrete form. Hence, high early strength cement with high $C_3S$ content and the hardening accelerator of powder type accelerating the hydration of $C_3S$ was used. And the properties of concrete were evaluated according to the hardening accelerator mixing ratio (0, 1.2, 1.6, 2.0). No big difference was found from the tests of both slump and air content. When 1.6 % or higher amounts of the hardening accelerator were mixed, the compressive strength of 10MPa was achieved at the age of 6 hours. From the test results of autogenous (drying) shrinkage and plastic shrinkage, it can be seen that there was a difference according to hydration reaction rate due to the addition of the hardening accelerator. However, it was shown that no problem arose with crack and durability. And it was shown that resistance to freezing-thawing, carbonation, and penetration were excellent.

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.203-208
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• 2022

The U.K. during the war on terrorism, the number of military serviceable resources decreased and the volunteer recruitment rate decreased due to the decline in the birth rate, but faced a situation in which complex security threats from IS and Russia gradually increased. As one of the measures to overcome these challenges, the British military promoted a policy to break down existing social conservatism and assign female personnel to close combat positions. The British military formed a consensus within the military through discovery of female military use cases, longitudinal studies, and combat experiments, and then conducted strategic communication to form a social consensus and collect public opinions. In addition, to improve the reliability of the policy, established a combat fitness evaluation system that any combatant who performs close combat should pass. In Korea, amid accelerating competition for hegemony between the U.S. and China, security threats are increasing due to a decrease in military serviceable resources caused by population cliffs. Therefore, the case of the British military will give us considerable implications while also helping to provide the direction necessary for establishing future women's workforce policies.