• Korean Journal of Child Studies
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• v.38 no.3
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• pp.19-32
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• 2017

Objective: This study examined whether the effects of fathering on school children's effortful control would be moderated by fathers' and mothers' own effortful control. Methods: The sample included 371 fourth grade children (47% boys) and their parents. Father's positive and negative parenting behaviors, parents' own effortful control and children's effortful control were assessed. Data were analyzed using hierarchical multiple regression in SPSS 18.0. Results: Parents' effortful control appeared to moderate the effect of fathering on children's effortful control. More specifically, parents' high levels of effortful control increased the effects of positive fathering on children's effortful control. Conclusion: Findings indicated that parents' effortful control tended to increase the effects of positive fathering (and lower the effects of negative fathering). This supports the importance of parents' effortful control in the development of school children's effortful control.

• Proceedings of the KIPE Conference
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• 2016.11a
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• pp.143-144
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• 2016

The circulating current control within the phase legs is one of the main control objectives in a modular multilevel converter (MMC) under different operating conditions. This paper proposes a control strategy of circulating currents in the MMC under unbalanced voltage by using a proportional-resonant (PR) controller. Under the unbalanced voltage, the circulating currents in the MMC consists of three components such as positive-sequence, negative-sequence, and zero-sequence circulating currents. With the PR controller, all components of the circulating current will be directly controlled in the stationary reference frame without decomposing into positive- and negative-sequence components. Thus, the ripples in the circulating currents and the DC current are suppressed under the unbalanced voltage. The effectiveness of the proposed method is verified by simulation results based on PSCAD/EMTDC simulation program.

• Agribusiness and Information Management
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• v.7 no.1
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• pp.10-20
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• 2015

This study aims to compare and analyze the differences of emotional responses between two types of e-magazines published - one with cinemagraph images and another with general still images. To conduct this study, a total of nine pages were prepared with different contents according to each theme and samples of e-magazine with a total of nineteen sections of images were exposed to a total of thirty persons of subjects. Fifteen persons were assigned to the experimental group viewing the cinemagraph images, and other fifteen persons were assigned to the control group viewing the general still images. As a result of the experiment, the emotional responses of the experimental group and the control group were significantly different. Twenty-eight items of positive emotional responses out of forty-two items of the emotional responses were more found in the experimental group, and fourteen items of negative emotional responses affected the control group more. In the experimental group where the differences in the mean value and significant differences were found, negative emotional responses were not examined but fourteen positive emotional response items such as Loveliness, Merriness, Freshness, Activeness, Attractiveness, Powerfulness, Heartwarming, Joyfulness, Interesting, Confidence, Excitement, Cheerfulness, Humorousness, and Amazement were found; in the control group, positive emotional responses were not found but three items of negative emotional responses such as Ambiguousness, Stuffiness, and Boredom were found.

• Journal of Preventive Medicine and Public Health
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• v.17 no.1
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• pp.295-298
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• 1984

The subjective symptom and other responded relations for 69 male workers handling organic solvent in xxx a pharmacy as exposure group and 87 male workers in noise workshop were studied and analyzied. It was concluded as follows. 1. The age of both exposure group and control group with the subjective symptom indicated a negative correlation. 2. Drinking and smoking of the exposure group complained of the subjective symptom shown the negative correlation and the control group also shown the positive correlation. 3. The occupational experience of the exposure group complained of the subjective symptom indicated the negative correlation and the control group also indicated the positive correlation.

• The Journal of the Korea Contents Association
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• v.18 no.1
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• pp.173-184
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• 2018

In human walking, muscle co-contraction which produces simultaneous activities of multiple muscles is important in motor control mechanism of the central nervous system. This study aims to understand positive and negative covariation mechanism of inter-muscle activities during walking. In this study, we measured electromyography (EMG) in leg muscles. To identify motor modules, we recored EMG from 4 leg muscles bilaterally (the tibialis anterior, medial gastrocnemius, rectus femoris and medial hamstring muscles) and performed non-negative matrix factorization (NMF) and principa component analysis (PCA). Then, we computed covariation values from various combinations between muscles or motor modules and used two-way repeated measures analysis of variance to identify significantly different covariation patterns between muscle combinations. As the results, we found significant differences between covariation values of muscle combinations (p < 0.05). muscle groups within the same motor modules produced the positive covariations. However, there were strong negative covariation between motor modules. There was negative covariation in all muscle combination. Stable inter-module negative covariation suggests that motor modules may be the control unit in the complex motor coordination.

• Journal of Power Electronics
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• v.10 no.2
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• pp.194-202
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• 2010

The main cause of degradation in an unbalanced stand-alone doubly-fed induction generator (DFIG) system is negative sequence components that exist in the generated stator voltages. To eliminate these components, a hybrid current controller composed of a proportional-integral controller and a resonant regulator is developed in this paper. The proposed controller is applied to the rotor-side converter of a DFIG system for the purpose of compensating the negative stator voltage sequences. The proposed current controller is implemented in a single positive rotating reference frame and therefore the controller can directly regulate both the positive and negative sequence components without the need for sequential decomposition of the measured rotor currents. In terms of compensation capability and accuracy, simulations and experimental results demonstrated the excellent performance of the proposed control method when compared to conventional vector control schemes.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.4
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• pp.283-290
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• 2022

This study proposes a voltage control scheme in a synchronous reference frame to improve the dynamic characteristics of double-conversion UPSs. UPSs need to control positive and negative sequence voltage, so that positive and negative sequence extractors are generally used to obtain each sequence of the voltage and current. Voltage and current controllers for each sequence are implemented. However, the extractor causes considerable delay, and the delay restricts the control performance, especially for the current controller. To improve the dynamics of the current controller, the proposed scheme adopts a unified current controller without separating positive and negative sequences. By using discrete-time current controller, the control bandwidth can be extended significantly so that negative sequence current can be controlled. To enhance the performance, an additional feed-forward technique for output voltage regulation is proposed. The validity of the proposed controller is verified by experiments.

• The Journal of Information Systems
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• v.29 no.3
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• pp.53-75
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• 2020

Purpose Despite the continued rise in the popularity of mobile MMORPGs, the previous studies mainly focused on negative results of playing MMORPG such as violence and game addiction. In addition, previous studies that verified game play motives were not enough to explain user's fundamental motives for MMORPG play. To verify the positive role of playing MMORPG, this study focused on stress coping strategies on continued play MMORPG, and divided factors into two dimensions: escapism and coping with system. The purpose of this study is to comprehensively identify the discriminatory effects of each factor on users' self-control, and the effect of self-constrol and behavioral adapatation on continued use intention for MMORPG. Design/methodology/approach This study was designed to examine the structural relationships among MMORPG users' escapism, system coping, self-control, behavioral adaptation and continued use intention for MMORPG. Findings The results from this study are as follow. First, the participants' effect-based escapism had a positive impact on self-control, whereas cause-based escapism had a negative impact on self-control. Next, proactive coping and reactive coping for system problem had a positive impact on self-control. In addition, Self-control had a positive impact on behavioral adaptation and continued use intention for MMORPG. Lastly, the behavioral adaptation to MMORPG had a positive impact continued use intention. The results of our study can suggest the positive effects of coping strategy on users' self-control and behavioral adaptation by applying the theory of both escapism and coping with system. Based on our results, game companies should develop contents that can gratify users' coping motives and enhance self-control and behavioral adaptation.

• The Korean Journal of Rehabilitation Nursing
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• v.14 no.2
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• pp.129-135
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• 2011

Purpose: This study was done to examine the effects of Tai Chi exercise program on BMI, positive and negative psychiatric symptoms in patient with schizophrenia. Methods: The participants were patient with schizophrenia in S psychiatric hospital in D city. Twenty five patients were assigned to experimental group, and 26 patients were assigned to control group. Data were collected from May 9, to July 8, 2011. The Tai Chi exercise program was conducted with a duration of 60 minutes, 2 times a week for 8 weeks (a total 8 times). Measures were BMI, positive and negative psychiatric symptoms. Data were analyzed using descriptive statistics, chi-square test and t-test with SPSS/WIN 19.0 version. Result: The experimental group received Tai Chi exercise program had a significant changes in BMI, positive and negative psychiatric symptoms. Conclusion: The results of this study indicate that Tai Chi exercise program is an effective intervention program to improve the BMI, positive and negative psychiatric symptoms of patients with schizophrenia.

• Journal of Industrial Technology
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• v.19
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• pp.217-226
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• 1999

A single phase to three phase power converter with cost effective and simple structure is proposed. The converter consists of rectifier and inverter. The rectifier is composed of a half wave rectifier, a dc link capacitor, and a current limiting inductor, and the inverter is of only two switches with PWM control. For negative sequence operation the inverter output voltage leads the line input by $60^{\circ}$, and for positive sequence operation the inverter output voltage leads by $60^{\circ}$. We can see that positive sequence operation shows higher output voltage, slight harmonic distortion(2%), and better performances such as high efficiency and high power factor. A mathematical model for system analysis is provided, and specifications for selection and control scheme both for start-up and for steady state are analyzed. comparison and operational limits of positive and negative sequence operation are performed, and simulations and experiments are executed to verify the proposed.