• The korean journal of orthodontics
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• v.24 no.1 s.44
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• pp.221-231
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• 1994

The short-term effects of plaque control instruction were studied in 42 adolescent orthodontic patients under active fixed treatment. At first visit, all the patients were received plaque control instruction using materials such as oral hygiene education slides, dentiform, disclosing agents, tooth brush and interdental brush. After that, Pateints were asked to perform the tooth brushing according to instructions. Such a procedure was repeated every week lot 3 weeks. Plaque index and bleeding index were scored once a week for 4 weeks and were compared according to ages, sex and duration with fixed appliance. The results were as follows: 1. Plaque control instruction was effective in reducing plaque accumulation and gingival inflammation of the orthodontic patients. 2. The effect of plaque control instruction was continued during 3 weeks among all groups of subjects, and it was prominent at the first week. 3. There was no statistically significant difference in the effects of the plaque control of instruction according to sex, ages, or duration with fixed appliances.

• Korean Journal of Childcare and Education
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• v.13 no.2
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• pp.1-19
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• 2017

Objective: The purpose of this study was to examine the relationship among perceived mothers'psychological control, affectionate-rational parenting and children's attributional style. The main and interaction effects of psychological control, affectionate-rational parenting on children's attributional style were also explored. Methods: The participants of this study were 253 children from elementary schools located in Seoul and Incheon. Data were analyzed through Pearson's correlation, and hierarchical regression using SPSS 22.0. Results: The major findings of this study were as follows. First, children's attributional style for negative events was positively associated with psychological control but negatively associated with affectionate-rational parenting. Moreover, attributional style for positive events was positively associated with only affectionate-rational parenting. Second, affectionate-rational parenting significantly influenced children's attributional style for both negative events and positive events. Finally, significant interaction effects of psychological control and affectionate-rational parenting on children's attributional style for negative events were observed. Conclusion/Implications: This study revealed that mothers' psychological control and affectionate-rational parenting are important factors in explaining children's attributional style. Such results could be used as an effective resource in developing parent education programs or intervention programs for attributional style.

• Korean Journal of Child Studies
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• v.29 no.6
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• pp.1-14
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• 2008

This study explored relationships between internal locus of control, ego-resilience, and behavior problems including effects of ego-resilience as mediating variables of behavior problems in 135 institutionalized children. Instruments were the Locus of Control (Min, 1999) and Ego-resilience (Yoon et al. 2001) scales and Korea-Child Behavior Checklist (Oh et al., 1997). Locus of control was administered to the children; ego-resilience and behavior problems were rated by teachers. Findings were that (1) internal locus of control related positively to ego-resilience and negatively to behavior problems; ego-resilience related negatively to behavior problems. (2) Effects of internal locus of control on behavior problems were mediated by ego-resilience; ego-resilience sub-factors of peer relationships and comprehension ability mediated relationships between internal locus of control and behavior problems.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.443-451
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• 2015

The stability of a multi-terminal direct current (MTDC) system is often influenced by its control strategy. To improve the stability of the MTDC system, the control strategy of the MTDC system must be appropriately adopted. This paper deals with estimating stability of a MTDC system based on the line-commutated converter based high voltage direct current (LCC HVDC) system with an inverter with constant extinction angle (CEA) control or a rectifier with constant ignition angle (CIA) control. In order to evaluate effects of two control strategies on stability, a MTDC system is tested on two conditions: initialization and changing DC power transfer. In order to compare the stability effects of the MTDC system according to each control strategy, a mathematical MTDC model is analyzed in frequency domain and time domain. In addition, Bode stability criterion and transient response are carried out to estimate its stability.

• Journal of Nutrition and Health
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• v.27 no.8
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• pp.819-827
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• 1994

The present study was undertaken to evaluate the effects of 50% buckwheat diet on the body weight, organ weight, urine albumin, urine glucose, plasma glucose and plasma lipid in normal rats and diabetic rats treated with streptozotocin(STZ). The food intake, body weight, the level of urine glucose in diabetic buckwheat groups were not significantly different with diabetic control group. The level of urine albumin was lower in raw and steam buckwheat group than in the diabetic control group. Compared to the normal control group, liver and kidney weights were heavier in the diabetic groups. Pancreas weight was heavier diabetic buckwheat groups than in normal and diabetic control groups. Fasting plasma glucose level of diabetic buckwheat groups significantly decreased by 18-37% compared with the diabetic control group. Plasma triglyceride level of diabetic buckwheat groups significantly decreased by 34-50% compared with the diabetic control group. Plasma total cholesterol level of diabetic buckwheat groups decreased by 15-27% compared with the diabetic control group. The level of HDL-cholesterol was not affected by buckwheat diet. These results indicate that buckwheat is an effective therapeutic regimen for the control of metabolic derangements in diabetics.

• Journal of the Korean Home Economics Association
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• v.39 no.7
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• pp.37-58
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• 2001

The Purpose of this study was to examine the direct or indirect effects of psychological family environment self-control, and friends characteristics of middle school students on their problem behaviors. Data were corrected from 520 senior students of middle school (266 boys and 254 girls) who reside in Inchon. The level of problem behaviors was directly influenced positively by closeness with friends and negatively by self-control and open communication with mothers. And the level of problem behaviors was indirectly influenced positively by intrafamily conflicts and negatively by self-control, parental monitoring and open communication with parents. Self-control was the most powerful predicator of problem behaviors of middle school students. Self-control was directly influenced positively by open communication with fathers and negatively by intrafamily conflicts. Closeness with friends was directly influenced positively by parental monitoring and negatively by self-control and open communication with mothers.

• The Journal of Korea Robotics Society
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• v.14 no.4
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• pp.348-356
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• 2019

The backdrivable servovalve is a desirable component for force and interaction control of hydraulic actuation systems because it provides direct force generation mechanical impedance reduction by its own inherent backdrivability. However, high parametric uncertainty and friction effects inside the hydraulic actuation system significantly degrade its advantage. To solve this problem, this letter presents a disturbance-adaptive robust internal-loop compensator (DA-RIC) to generate ideal interactive control performance from the backdrivable-servovalve-based system. The proposed control combines a robust internal-loop compensator structure (RIC) with an explicit disturbance estimator designed for asymptotic disturbance tracking, such that the controlled system provide stable and ideal dynamic behavior for impedance control, while completely compensating the disturbance effects. With the aid of a backdrivable servovalve, we show that the proposed control structure can be implemented based on a simplified nominal model, and the controller enables implementation without accurate knowledge of the target system parameters and disturbances. The performance and properties of the proposed controller are verified by simulation and experiments.

• Structural Engineering and Mechanics
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• v.41 no.3
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• pp.349-363
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• 2012

Fuzzy logic based control has recently been proposed for regulating the properties of magnetorheological (MR) dampers in an effort to reduce vibrations of structures subjected to seismic excitations. So far, most studies showing the effectiveness of these algorithms have focused on the use of a single MR damper. Because multiple dampers would be needed in practical applications, this study aims to evaluate the effects of multiple individually tuned fuzzy-controlled MR dampers in reducing responses of a multi-degree-of-freedom structure subjected to seismic motions. Two different fuzzy-control algorithms are considered, a traditional controller where all parameters are kept constant, and a gain-scheduling control strategy. Different damper placement configurations are also considered, as are different numbers of MR dampers. To determine the robustness of the fuzzy controllers developed to changes in ground excitation, the structure selected is subjected to different earthquake records. Responses analyzed include peak and root mean square displacements, accelerations, and interstory drifts. Results obtained with the fuzzy-based control schemes are compared to passive control strategies.

• Fisheries and Aquatic Sciences
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• v.23 no.8
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• pp.20.1-20.18
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• 2020

Background: Olive flounder, Paralichthys olivaceus, is an economically important aquaculture species in Korea. Olive flounders have been heavily damaged by streptococcal infections every year and are treated with antibiotics. However, antibiotic abuse is causing the emergence of resistant strains, and to overcome this, research has shown that new antibiotics must be applied. Tylosin is a relatively safe antibiotic and has good activity against Gram-positive bacteria and mycoplasma. We studied the therapeutic effects and side effects of tylosin on Streptococcus parauberis-infected olive flounder. Methods: After artificial infection of olive flounder with S. parauberis SPOF18J3, an appropriate dose of tylosin was confirmed by intramuscular injection (I.M.) at 2.5, 5, 10, and 15 mg/kg, and oral administration at 10 and 20 mg/kg. After I.M. and oral administration dosing of tylosin, side effects were confirmed by serological analysis, histopathological analysis, and median lethal dose (LD₅₀) analysis at both an appropriate concentration and a high concentration. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test (p < 0.05). Results: The appropriate I.M. and oral administration concentration of tylosin administered to olive flounder infected with S. parauberis SPOF18J3 was found to be 10 mg/kg. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were showed not significantly different between the control group and the experimental groups. The histopathologic results showed mild inflammatory responses in muscle and tubular vacuolization and tubular atrophy appeared, but there were no significant differences between the groups. The LD₅₀ was confirmed to be 461 mg/kg. Conclusion: In this study, an effective treatment method was provided by verifying the treatment effects and side effects of tylosin in olive flounder infected with S. parauberis, which can be applied directly to aquaculture sites. In addition, these results may be used as a reference for evaluation required upon request to obtain approval for tylosin antibiotics as fishery antibiotics in Korea. After approval, it is possible that a fishery disease manager will be able to prescribe and sell the antibiotic tylosin.

• Structural Engineering and Mechanics
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• v.87 no.2
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• pp.117-127
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• 2023

To efficiently attenuate seismic responses of a structure, a novel pneumatic-driven active dynamic vibration absorber (PD-ADVA) is proposed in this study. PD-ADVA aims to realize closed-loop control using a simple and intuitive control algorithm, which takes the structure velocity response as the input signal and then outputs an inverse control force to primary structure. The corresponding active control theory and phase control mechanism of the system are studied by numerical and theoretical methods, the system's control performance and amplitude-frequency characteristics under seismic excitations are explored. The capability of the proposed active control system to cope with frequency-varying random excitation is evaluated by comparing with the optimum tuning TMD. The analysis results show that the control algorithm of PD-ADVA ensures the control force always output to the structure in the opposite direction of the velocity response, indicating that the presented system does not produce a negative effect. The phase difference between the response of uncontrolled and controlled structures is zero, while the phase difference between the control force and the harmonic excitation is π, the theoretical and numerical results demonstrate that PD-ADVA always generates beneficial control effects. The PD-ADVA can effectively mitigate the structural seismic responses, and its control performance is insensitive to amplitude. Compared with the optimum tuning TMD, PD-ADVA has better control performance and higher system stability, and will not have negative effects under seismic wave excitations.