• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.171-179
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• 2023

This study was conducted to evaluate the association between knowledge of Coronavirus disease 2019 (COVID-19), perception of infection control and practice of infection control among dental hygienists. The questionnaires consisted of 9 demographic questions, 10 questions about COVID-19 knowledge, and 36 questions about perception and practice of infection control. The study analyzed 120 participants' data gathered from May 1 to May 31, 2021. For data analysis, T-test, ANOVA, and Pearson correlation were used. As a result, COVID-19 knowledge was 6.59 out of 10, the perception of infection control was 3.57 out of 4 and the practice of infection control was 3.55 out of 4. The COVID-19 knowledge(r=0.485) and perception of infection control(r=0.614) were significantly positively related to practice of infection control. To improve the practice of infection control in the dental field, education of infection control should be mandatory for dental hygienists. Also, the practice of infection control following "Dental Infection Control Standard Policy & Procedure" must be mandatory.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.9
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• pp.777-785
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• 2000

This paper provides a guideline for the determination of compliance characteristics and the proper location of the compliance center in typical peg-in-hole and peg-out-hole tasks using hands. We first observe the fact that some of coupling stiffness elements cannot be planned arbitrarily. The given peg-in/out-hole tasks are classified into two contact styles. Then, we analyze concluded of the operational siffness matrix, which achieve the give peg-in/out-hole tasks effectively for each case. It is concluded that the location of the compliance center on the peg and the coupling stiffness element existing between the translational and the rotational direction play ompliance on the peg and the coupling siffness element existing between the translational and the rotational direction play important roles for successful peg-in/out-hole tasks. The analytic results verified through simulations.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.1304-1308
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• 2005

This paper presents the case that the existing analog control systems were retrofitted with digital DCS(Distributed Control System)s for boiler unit in thermal power plant. Replacement of existing worn-out or obsolete analog control systems has been considered. Replacement of existing analog control systems with another analog control systems has lots of difficulties in maintaining the systems due to being out of stock. Due to those difficulties, existing analog control systems have been retrofitted with digital DCSs in many industrial sites. KEPRI(Korea Electric Power Research Institute) accomplished the project that retrofitted analog control systems with the developed DCSs for boiler unit in middle-scale coal-fired thermal power plant. The benefits of an upgrade to digital control include a increase of reliability due to system redundancy, ease of modifying the control logic and the parameters of function block, ease of maintenance due to available spare parts, improvement of information display, ease of modifying MMI(Man Machine Interface) displays, a increase in system availability, and improvement of control performance. This paper describes how to use the parameters of existing analog controllers, the implementation of digital PID controller, control system configuration for boiler unit in thermal power plant, some boiler control loops, control result during commissioning, and the comparison of boiler characteristic test data after retrofitting with the existing test data.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.1
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• pp.137-144
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• 1998

For a model system consisted of four pneumatic cylinders with strokes of 10, 20, 40 and 80 mm, investigation was carried out experimentally and numerically about the reliability of system with elastic and viscous load. The elastic load affects the performance of each cylinder in cylinder series, and changes the time lag and the velocity of the piston which makes the positioning control rather difficult. Taking the effects of the elastic load into consideration, positioning can be carried out comparatively smoothly by only adjusting the driving timing. The effect of a viscous load reduces the vibration of each moving body in the cylinder series and also reduces the over-travelled distance which happens when several cylinders move at the same time. For reasons, a positioning with a viscous load can be relatively smoothly carried out even without the timing control.

• Journal of Trauma and Injury
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• v.22 no.1
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• pp.44-50
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• 2009

Purpose: The purpose of this study was to evaluate the causes of blow-out fractures, the computed tomography findings, and the associated facial bone fractures in aged patients. Methods: This study was performed by conducting a chart review. From January 2004 to December 2007, the patients who visited the emergency room of Asan Medical Center and were diagnosed as having a blow-out fracture were included in the study population. Patients 60 years of age or older were grouped as the aged group while patients younger than 60 years of age were grouped as the control group. Results: Between the aged group and the control group, there was a difference in the causes of blow-out fractures. The most common cause of blow-out fracture was a slip down in the aged group and violence in the control group (p<0.05). There were no differences in associated symptoms. Extraocular muscle herniation was the only statistically different computed tomography findings. In associated facial bone fractures, the most common fractures were the zygoma in the aged group and the nasal bone in the control group (p<0.05). Conclusion: In patients 60 years of age or older, the most common cause of blow-out fracture was a slip down, and the most common associated facial bone fracture was a zygomatic fracture.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.23 no.2
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• pp.161-171
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• 2016

Purpose: This study was conducted to investigate factors influencing influenza infection control compliance in nurses, including knowledge about, and awareness of infection control. Methods: The study participants were 168 nurses who worked at a hospital in J Province. Data were collected by self-reported questionnaires in April 2015. Collected data were analyzed using SPSS/WIN 20.0 program. Results: Mean score for knowledge about droplet precaution was 12.16 out of 16.00. Mean score for awareness about droplet precautions was 3.49 out of 4.00, and mean score for droplet precaution compliance was 3.33 out of 4.00. There was a positive correlation among knowledge, awareness and compliance (p<.001). Awareness, knowledge and experience of seasonal influenza education were the significant factors affecting the level of compliance (37.8%). Conclusion: Study results indicate that an educational program focusing on strategies to change nurses' awareness would be effective in improving infection control of respiratory virus and droplet precaution compliance in hospitals.

• Smart Structures and Systems
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• v.3 no.4
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• pp.405-422
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• 2007

A new hybrid damping technique for vibration reduction in flexible structures, wherein a combination of layers of hard passive damping alloys and active (smart) magnetostrictive material is used to reduce vibrations, is proposed. While most conventional vibration control treatments are based exclusively on either passive or active based systems, this technique aims to combine the advantages of these systems and simultaneously, to overcome the inherent disadvantages in the individual systems. Two types of combined damping systems are idealized and studied here, viz., the Noninteractive system and the Interactive system. Frequency domain studies are carried out to investigate their performance. Finite element simulations using previously developed smart beam elements are carried out on typical metallic and laminated composite cantilever beams treated with hybrid damping. The influence of various parameters like excitation levels, frequency (mode) and control gain on the damping performance is investigated. It is shown that the proposed system could be used effectively to dampen the structural vibration over a wide frequency range. The interaction between the active and passive damping layers is brought out by a comparative study of the combined systems. Illustrative comparisons with 'only passive' and 'only active' damping schemes are also made. The influence and the mode dependence of control gain in a hybrid system is clearly illustrated. This study also demonstrates the significance and the exploitation of strain dependency of passive damping on the overall damping of the hybrid system. Further, the influence of the depthwise location of damping layers in laminated structures is also investigated.

• International Journal of Concrete Structures and Materials
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• v.11 no.1
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• pp.69-84
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• 2017

This paper presents results of an experimental investigation on the behaviour of bond between external glass fibre reinforced polymer reinforcement and concrete exposed to three different environmental conditions, namely, temperature cycles, wet-dry cycles and outdoor environment separately for extended durations. Single shear tests (pull-out test) were conducted to investigate bond strengths (pull-out strengths) of control (unexposed) and exposed specimens. Effect of the exposure conditions on the compressive strength of concrete were also investigated separately to understand the effect of changing concrete compressive strength on the pull-out strength. Based on the comparison of experimental results of exposed specimens to control specimens in terms of bond strengths, failure modes and strain profiles, the most significant degradation of pull-out strength was observed in specimens exposed to outdoor environment, whereas temperature cycles did not cause any deterioration of strength.

• Child Health Nursing Research
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• v.22 no.2
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• pp.97-106
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• 2016

Purpose: The purpose of this study was to identify the relationship between mother child-rearing attitude, language control styles and preschool child's social competence, and also, to provide a basis for development of a program to promote preschool child's social competence. Methods: The present study was a descriptive research. Participants in this study were a convenience sample of 300 preschool children and their mothers. For the final analysis 264 questionnaires were used after eliminating questionnaires with incomplete responses. Data were analyzed using the SPSS 18.0 program. Results: The mean score for mother's child-rearing attitude was $3.31{\pm}0.25$ out of 5 points, for hierarchical language control styles ($2.76{\pm}0.62$), commanding ($1.95{\pm}0.58$), and humanistic ($2.48{\pm}0.62$) out of 5 points, and for child's social competence, $3.50{\pm}0.34$ out of 5 points. Negative correlations were found between commanding language control styles and child's social competence (r=-.34, p<.001), and between commanding language control style and mother's child-rearing attitude (r=-.50, p<.001). Conclusion: The results demonstrate the importance of the quality of mother's child-rearing attitude and language control styles for child's social competence. It is suggested that promotion programs to enhance preschool child's social competence should be developed in conjunction with the parenting related environment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.177-181
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• 1992

For this study, a new hydraulic control unit which designed in compact compared to the currently manufactured hydraulic control unit for ABS has been introduced and its experimental model has been made. Based on the basic principle as ABS using braking force characteristics against slip ratio of tire, half car model bench tester were designed and made to make an analysis of braking effect of the new hydraulic control unit. Experiment for slip ratio characteristics of tire has been carried out using half car model bench tester and with the results of this experiment and control experiment of the new hyraulic control unit, the experiment result of the characteristics of tire and control experiment were compared to find out their correspondence. And furthermore, slip ratio characteristics of the new hydraulic control unit has been studied based on the experiment result of slip ratio characteristics of tire through simulation and compared with experiment result.