• 약학회지
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• 제32권2호
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• pp.129-136
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• 1988

Effects of the selective alpha-adrenoceptor agonists, clonidine, oxymetazoline and phenylephrine, on heart rate and contractile force were investigated in the isolated frog atria and it was attempted to examine the influence of adrenoceptor antagonist upon those. Clonidine produced dose-dependent negative chronotropic and positive inotropic effects. The negative chronotropic effect was significantly attenuated in the presence of prazosin and yohimbine but not propranolol. The positive inotropic effect was significantly attenuated by prazosin, yohimbine and propranolol. Oxymetazoline produced dose-dependent negative chronotropic and inotropic effects. The negative chronotropic effect was significantly attenuated in the presence of prazosin, which was partially augmented by yohimbine but was not affected by propranolol. The negative inotropic effect was not affected by propranolol but it was partially augmented by yohimbine and was partially attenuated by prazosin. Phenylephrine produced dose-dependent positive chronotropic and inotropic effects. The positive chronotropic and inotropic effect were significantly attenuated in the presence of propranolol but were not affected by prazosin and yohimbine. These results suggest that the negative chronotropic effect by clonidine and oxymetazoline is mediated by alpha-adrenoceptors, the positive chronotropic and inotropic effects by phenylephrine are mediated by beta-adrenoceptors, and alpha-adrenoceptors mediated the inhibitory chronotropic responses exists in the isolated frog atria.

• Human Ecology Research
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• 제53권3호
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• pp.265-277
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• 2015

This study examines child emotional intelligence in relation to mother's emotional expressiveness and reaction to child negative emotions. A sample of 352 children and mothers from 4 elementary schools in Seoul and Gyeonggi participated in the study. Child emotional intelligence and mother's reaction to child negative emotions were evaluated by child-report, and mother's emotional expressiveness was assessed by mother-report. Data were analyzed by descriptive statistics, two-way analysis of variances, Pearson's correlation and multiple regression analyses. The findings were as follows. First, mothers of boys showed more oversensitive-reaction to child negative emotions than mothers of girls. Mothers of 6th-graders showed more emotion-minimizin-greaction to child negative emotions than mothers of 5th-graders. Second, girls showed a higher level of overall emotional intelligence than boys. Girls showed a higher level of emotion expression and emotion regulation than boys. The 5th-graders showed higher level of emotion expression than 6th-graders; however, 6th graders showed a higher level of emotion perception than 5th-graders. Third, more emotion-coaching-reaction and less oversensitive-reaction by mothers predicted a better emotional intelligence of children. A mother's appropriate emotional socialization behaviors associated with child emotional intelligence were discussed.

• Journal of Power Electronics
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• 제15권1호
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• pp.268-277
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• 2015

In this paper, a dual-converter three-phase pulse width modulation (PWM) rectifier based on unbalanced one-cycle control (OCC) strategy is proposed. The proposed rectifier is used to eliminate the second harmonic waves of DC voltage and distortion of line currents under unbalanced input grid voltage conditions. The dual-converter PWM rectifier employs two converters, which are called positive-sequence converter and negative-sequence converter. The unbalanced OCC system compensates feedback currents of positive-sequence converter via grid negative-sequence voltages, as well as compensates feedback currents of negative-sequence converter via grid positive-sequence voltages. The AC currents of positive- and negative-sequence converter are controlled to be symmetrical. Thus, the workload of every switching device of converter is balanced. Only one conventional PI controller is adopted to achieve invariant power control. Then, the parameter tuning is simplified, and the extraction for positive- and negative-sequence currents is not needed anymore. The effectiveness and the viability of the control strategy are demonstrated through detailed experimental verification.

• Journal of Power Electronics
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• 제19권5호
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• pp.1326-1335
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• 2019

Common mode (CM) chokes are a crucial part in EMI filters for mitigating the electromagnetic interference (EMI) of switched-mode power supplies (SMPS) and for meeting electromagnetic compatibility standards. However, the parasitic capacitances of a CM choke deteriorate its high frequency filtering performance, which results in increases in the design cycle and cost of EMI filters. Therefore, this paper introduces a negative capacitance generated by a negative impedance converter (NIC) to cancel the influence of equivalent parallel capacitance (EPC). In this paper, based on a CM choke equivalent circuit, the EPCs of CM choke windings are accurately calculated by measuring their impedance. The negative capacitance is designed quantitatively and the EPC cancellation mechanisms are analyzed. The impedance of the CM choke in parallel with negative capacitances is tested and compared with the original CM choke using an impedance analyzer. Moreover, a CL type CM filter is added to a fabricated NIC prototype, and the insertion loss of the prototype is measured to verify the cancellation effect. The prototype is applied to a power converter to test the CM conducted noise. Both small signal and EMI measurement results show that the proposed technique can effectively cancel the EPCs and improve the CM filter's high frequency filtering performance.

• 한국보육지원학회지
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• 제14권6호
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• pp.241-255
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• 2018

Objective: The purpose of this research was to examine the moderating effect of children's negative emotionality on the relationship between maternal attitude toward children's emotional expression based on the differential susceptibility model. Methods: Participants were 216 preschool children including 116 boys and 100 girls from day care centers and preschools located in Chungchung province and Seoul. EAS was used to measure the children's negative emotionality. The children's empathy quotient was used to measure empathy. Mothers reported their attitude toward children's emotional expression. Results: The results revealed that the association between empathy and maternal suppression of children's emotional expression was significant only for the children with high levels of negative emotionality. Moreover, the magnitude of association between empathy and maternal acceptance of children's emotional expression was greater for high levels of negative emotionality. Conclusion/Implications: It was concluded that these findings supported the differential susceptibility model.

• 한국보육지원학회지
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• 제15권1호
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• pp.1-14
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• 2019

Objective: This study examined the effects of mothers' reactions to children's negative emotions on the children's social power through children's emotional regulation ability. Methods: A total of 339 four-year and five- year old preschoolers, and their mother and teachers in Seoul and Gyeongi participated in the study. Data were analyzed by path analysis using AMOS 21.0 program. Results: The results were as follows: First, mothers' reactions to children's negative emotions were significantly related to children's emotional regulation ability and social power. Also, children's emotional regulation ability was significantly associated with children's social power. Second, mothers' reactions to children's negative emotions had indirect effects on social power - prosocial leadership and social dominance-through children's emotional regulation ability. Conclusion/Implications: The results of this study revealed the mediating role of children's emotional regulation ability between mothers' reactions to children's negative emotions and children's social power. Also, these findings will be helpful in order to understand children's social power and to develop parent education programs.

• 스트레스연구
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• 제26권4호
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• pp.350-355
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• 2018

본 연구에서는 불확실성에 대한 인내력 부족과 부정적인 문제해결 지향 및 걱정간의 관계를 알아보고자 하였다. 이를 위해 충북에 소재한 4년제 대학교에 재학 중인 531명을 대상으로 불확실성에 대한 인내력 부족, 부정적인 문제해결 지향, 걱정에 관한 설문지를 실시하여 자료를 수집하였다. 그 결과, 불확실성에 대한 인내력 부족과 부정적인 문제해결 지향과의 상관이 유의하였다. 또한 불확실성에 대한 인내력 부족과 걱정 간의 관계에서 부정적인 문제해결 지향이 매개효과를 지니는 것으로 나타났다. 이로 볼 때, 걱정이 높은 사람들을 대상으로 불확실성에 대한 인내력과 부정적인 문제해결 지향에 초점을 두어 개입을 하는 것이 유용할 수 있겠다. 추가적으로 본 연구의 의의와 한계점에 대해서도 논의하였다.

• PNF and Movement
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• 제12권1호
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• pp.13-17
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• 2014

Purpose: To determine the normative data for the correlation of spinal, pelvic parameters with foot pressure in the young subjects. Methods: The subjects of this study were 39 patients in healthy adults. The Formetric-III was used to measure of spinal alignment. The pedoscan was used to measure of foot pressure. The correlation of trunk imbalance, trunk inclination, lateral deviation with foot pressure. The foot pressure measurement was consisted of maximal/mean pressure, weight contribution. Result: There was a negative correlation of trunk inclination with Max_R. There was a negative correlation of trunk inclination with Max_R. There was a positive correlation of trunk imbalance with Max_L. There was a positive correlation of lumbar lordosis with Mean_R_front, Lt. posterior weight distribution. There was a negative correlation of lumbar lordosis with Lt., Rt. in distribution There was a negative correlation of pelvic tilt with Mean_R_front, Lt. posterior weight distribution. There was a positive correlation of pelvic tilting with Rt. weight distribution, Lt. posterior weight distribution. There was a negative correlation of pelvic torsion with Lt. weight distribution, Rt. posterior weight distribution. There was a negative correlation of pelvic rotation with Lt. weight distribution, Lt. posterior weight distribution. Conclusion: The data obtained from the study may be used for future studies related to correlation of the spinal, pelvic deviation with foot pressure.

• 한국정보시스템학회지:정보시스템연구
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• 제30권2호
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• pp.79-103
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• 2021

Purpose Based on consumers' economic, psychological, self-development and conversion costs, this study discusses the relationship between consumers' negative attitude to their shadow work during the course of using self-service in unmanned supermarkets and their behavior. Design/methodology/approach Along with the Hirschman(1970)'s EVLN(Exit, Voice, Loyalty, and Neglect) reviewed, the proposed model of this study is based on the S-O-R model(Mehrabian and Russel, 1974) and mental accounting theory(Thaler, 1999), having empirical validation. Findings In the process of visits and consumption in unmanned supermarkets, increasing economic and psychological benefits can effectively reduce consumers' negative attitudes towards shadow work. In addition, the increase in switching costs will also effectively reduce consumers' negative attitudes towards shadow work. When shadow work holds a negative attitude, all the three kinds of actions will occur. Unmanned supermarket operators use consumers to create value while giving a certain return to them, which is conducive to the sustainable development of unmanned supermarket enterprises.

• Steel and Composite Structures
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• 제38권4호
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• pp.415-430
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• 2021

The effective flange width was usually introduced into elementary beam theory to consider the shear lag effect in steel-concrete composite beams. Previous studies have primarily focused on the effective width under positive moments and elastic loading, whereas it is still not clear for negative moment cases in the normal service stages. To account for this problem, this paper proposed simplified formulas for the effective flange width and reinforcement stress of composite beams under negative moments in service stages. First, a 10-degree-of-freedom (DOF) fiber beam element considering the shear lag effect and interfacial slip effect was proposed, and a computational procedure was developed in the OpenSees software. The accuracy and applicability of the proposed model were verified through comparisons with experimental results. Second, a method was proposed for determining the effective width of composite beams under negative moments based on reinforcement stress. Employing the proposed model, the simplified formulas were proposed via numerical fitting for cases under uniform loading and centralized loading at the mid-span. Finally, based on the proposed formulas, a simplified calculation method for the reinforcement stress in service stages was established. Comparisons were made between the proposed formulas and design code. The results showed that the design code method greatly underestimated the contribution of concrete under negative moments, leading to notable overestimations in the reinforcement stress and crack width.