• Title/Summary/Keyword: variable gain

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A Study of Urban Employed Wives무 Family Financial Management and Economic Well-Being (도시 취업주부의 가계재무관리행동과 경제복지감)

  • 계선자
    • Journal of Family Resource Management and Policy Review
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    • v.4 no.1
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    • pp.95-111
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    • 2000
  • The family financial management is the important element which has a effect on the improvement of family economic well-being. Thus the study sets up human & material resources and requirement as an input factor, family financial management as an throughput factor, and economic well-being as an output factor, and then identifies if there are some relationships among them by using a systematic approach of family financial management. The questionaires were distributed to 600 employed wives by carrying out cluster sampling and disproportional stratified sampling. The 573 cases of them were used as the mean, ratio, Pearson’s Correration, ANOVA, factors analysis, and Stepwise Regression using the SAS/PC+. The major findings of the study are as follows: 1) A practical application of information as on input variable, appears the fator which has an important effect upon the throughput factor, that is, family financial management. The employed wives should manage a lot of resources in rapidly changing social-economic circustances. So it shows that not only they should take informations open to their daily life and then make practical use of them in managing their family finance, but also they must be capable of judging and accepting reasonable informations in order to gain and manage resources suitable to the characteristics of family finance and family members’need. 2) There was significant relationship between the employed wives’family financial management and family economic well-being, focused on the systematic theory of family financial management. This study provides for the information to develope the program for the employed wives’family financial planning and counseling.

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A Study on the Relationship Between Multinationality and Performance: Evidence from China's Firms

  • WU, Renhong;HE, Yugang
    • The Journal of Industrial Distribution & Business
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    • v.10 no.7
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    • pp.7-16
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    • 2019
  • Purpose - Economic globalization provides firms with a new channel to gain benefits from foreign countries. Therefore, using the real MNEs, this paper set China's firms as an example to explore the relationship between multinationality and performance. Research design, data, and methodology - Panel data from 2008 to 2017 was used and 390 multinational firms listed in China's A-share market was selected. Additionally, related econometric methods were employed to analyze the relationship between multinationality and performance in this study. The return on assets was treated as a dependent variable, and the sales of a firm, the firm age, the debt asset ratio of a firm, the ratio of foreign sales to total sales and the enterprise properties were treated as independent variables. All of these factors were used to conduct an empirical analysis. Results - The empirical findings in this study revealed that there is a linear relationship between multinationality and performance, as well as that non state-owned enterprises (non-SOEs) have a greater effect on the relationship between multinationality and performance than that of the state-owned enterprises (SOEs). Conclusions - On the basis of evidences this paper provided, China's government should take measures in the future to help China's firms when they fulfil international economic activities.

A Study of Urban Housewives Financial Stress, Coping Strategies and Their Economic Well-Being (도시주부의 재정 스트레스, 대처행동 및 경제복지감 연구)

  • 유을용;계선자
    • Journal of Families and Better Life
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    • v.21 no.2
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    • pp.155-173
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    • 2003
  • The purpose of this study was to gain an understanding about urban housewives' stress in family financial management, their coping strategies, and their sense of economic well-being, which will eventually provide some baseline data for policy development. The findings of this study are summarized in the following. First, the mean score of the level of financial management-related stress among urban housewives was 2.61 when the maximum level was set at 5. In order to overcome the stress from financial management, housewives utilized various strategies, such as purchasing management, financial planning, financial information gathering, getting a loan, and delaying payments. The average level of economic well-being among urban housewives was 2.82 when the maximum level was 5. Second, among socio-demographic factors, the family's monthly income and the husband's job satisfaction were the two most significant factors that affected the level of financial management stress among housewives. Third, there was a difference in employing coping strategies according to the level of stress. The group with a higher level of financial stress employed more coping strategies than the group with, a lower level of stress. Fourth, there were differences in the level of economic well-being, depending on the types of coping strategies employed. Fifth, the results from regression analyses, which were conducted to determine the relative explanatory power of different independent variable groups including subjective factors, financial management stress, and coping strategies, showed that socio-demographic and objective economic factors significantly affected economic well-being.

Analysis of Current Control Stability using PI Control in Synchronous Reference Frame for Grid-Connected Inverter with LCL Filter (LCL 필터를 사용하는 계통연계형 인버터의 동기좌표계 PI 전류제어 안정도 해석)

  • Jo, Jongmin;Lee, Taejin;Yun, Donghyun;Cha, Hanju
    • The Transactions of the Korean Institute of Power Electronics
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    • v.21 no.2
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    • pp.168-174
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    • 2016
  • In this paper, current control using PI controller in the synchronous reference frame is analyzed through the relationship among bandwidth, resonance frequency, and sampling frequency in the grid-connected inverter with LCL filter. Stability is investigated by using bode plot in frequency domain and root locus in discrete domain. The feedback variable is the grid current, which is regulated by the PI controller in the synchronous reference frame. System delay is modeled as 1.5Ts, which contains computational and PWM modulator delay. Two resonance frequencies are given at 815 Hz and 3.16 kHz from LCL filter parameters. Sufficient phase and gain margins can be obtained to guarantee stable current control, in case that resonance frequency is above one-sixth of the sampling frequency. Unstable current control is performed when resonance frequency is below one-sixth of the sampling frequency. Analysis results of stability from frequency response and discrete response is the same regardless of resonance frequency. Finally, stability of current control based on theoretical analysis is clearly verified through simulation and experiment in grid-connected inverters with LCL filter.

The Design of MRAC with Fuzzy Adaptation Law (퍼지 적응 법칙을 갖는 기준모델 적응제어기 설계)

  • Cho, Jong-Hoon;Kwon, Hyuk-Jin;Seo, Seung-Hyun;Moon, Dong-Uk;Nam, Moon-Hyon
    • Proceedings of the KIEE Conference
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    • 1995.07b
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    • pp.685-688
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    • 1995
  • In this paper we proposed new scheme replacing adaptive mechanism part in MRAC by fuzzy logic in order to improve transient response in adaptive control system. Conventional adaptive control system has good performance in steady state but it has large error or problem with rise time in transient state. We need to increase adaptation gain of control variable but it causes robustness problem that makes ststem unstable for set-point, load-variation, and dynamic change. To demonstrate presented FTAC(fuzzy tunning adaptive control)'s superiority, presented method is introduced for a class of SISO systems and compare with MRAC. By analyzing simulation result, we can see transient response is improved and the system is not affected by disturbance in proposed method in comparison to MRAC.

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Application of Evaluation Criteria for Web sites to Sexuality Education (인터넷상의 성교육 사이트 평가기준의 적용)

  • Kang, Nam-Mi;Hyun, Tai-Sun;Lee, Pil-Ryang;Kim, Jin
    • Women's Health Nursing
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    • v.7 no.3
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    • pp.373-381
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    • 2001
  • Web sites on the internet are excellent resources for the younger generation to gain information related to sexuality education. The potential benefits of the information of sexuality education on web sites are obvious. But the information of sexuality education on web sites could also result in potentially negative effects. Yet the quality of the information of sexuality education on web sites is variable and difficult to assess. There is no rating criteria for quality assessment of the information on web sites. The rating criteria for quality assessment of information of sexuality education were investigated and reviewed. Among the criteria, best 15 items to evaluate the information of sexuality education on web sites were selected and identified in this study. 15 items were categorized to reliability ( 3 items ), content ( 6 items ), goal ( 2 items ), design & technology ( 4 items ). This 15-items questionnaires is considered as commonly implementable criteria for the information of sexuality education on web sites in Korean. 20 web sites related to sexualtiy education were evaluated and the results were discussed.

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On the Adaptive 3-dimensional Transform Coding Technique Employing the Variable Length Coding Scheme (가변 길이 부호화를 이용한 적응 3차원 변환 부호화 기법)

  • 김종원;이신호;이상욱
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.7
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    • pp.70-82
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    • 1993
  • In this paper, employing the 3-dimensional discrete cosine transform (DCT) for the utilization of the temporal correlation, an adaptive motion sequence coding technique is proposed. The energy distribution in a 3-D DCT block, due to the nonstationary nature of the image data, varies along the veritical, horizontal and temporal directions. Thus, aiming an adaptive system to local variations, adaptive procedures, such as the 3-D classification, the classified linear scanning technique and the VLC table selection scheme, have been implemented in our approach. Also, a hybrid structure which adaptively combines inter-frame coding is presented, and it is found that the adaptive hybrid frame coding technique shows a significant performance gain for a moving sequence which contains a relatively small moving area. Through an intensive computer simulation, it is demonstrated that, the performance of the proposed 3-D transform coding technique shows a close relation with the temporal variation of the sequence to be code. And the proposed technique has the advantages of skipping the computationally complex motion compensation procedure and improving the performance over the 2-D motion compensated transform coding technique for rates in the range of 0.5 ~ 1.0 bpp.

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A Mentoring Program for Stress Management among Korean Adolescents (청소년의 스트레스 관리를 위한 멘토링 프로그램)

  • Shin, Yun-Hee;Ahn, Yang-Heui
    • Research in Community and Public Health Nursing
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    • v.20 no.2
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    • pp.259-268
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    • 2009
  • Purpose: The purpose of this study was to develop a mentoring program for stress management among Korean adolescents and to assess the effects of the program. Methods: The nonequivalent control group (CG) pretest-posttest design was used in this study. The mentoring intervention was delivered to 18 middle school students (males and females) but nothing was done to the control group consisting of 18 students. The mentoring intervention was conducted by seven nursing students who participated in the program as mentors using various methods such as individual meetings and group activities. The dependent variable was stress level. Results: The program consisted of group and individual mentoring. At follow-up, although the mentees's satisfaction was high and they stated qualitatively positive experience, the difference of stress level between the two groups was not significant. Conclusion: If future mentoring programs reflect the limitation of the current program, they may have potential as developmentally appropriate interventions for stress management of adolescents, and enable nursing students to gain confidence in their professional capability.

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Fuzzy-PI controller for molten steel level of continuous casting process (연속 주조의 용강 높이 제어를 위한 퍼지-PI 제어기)

  • Joo, Moon-G.;Kim, Do-E.;Kim, Ho-K.;Kim, Jong-M.
    • Journal of the Korean Institute of Intelligent Systems
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    • v.18 no.4
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    • pp.488-493
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    • 2008
  • A mathematical model of molten steel level for continuous casting process is presented, where the molten steel level, input and output flow in the mold, the relation between stopper position and input flow etc. are considered. The mathematical model is implemented and simulated by using MATLAB. Comparing the result of molten steel level from the simulator with that of real plant, the performance of the model is shown to be reasonable. By using this simulator, it is shown that PI controller with variable P gain, adjusted by fuzzy logic system, has better control result than conventional PI controller.

A High Efficiency LLC Resonant Converter-based Li-ion Battery Charger with Adaptive Turn Ratio Variable Scheme

  • Choi, Yeong-Jun;Han, Hyeong-Gu;Choi, See-Young;Kim, Sang-Il;Kim, Rae-Young
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.124-132
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    • 2018
  • This paper proposes an LLC resonant converter based battery charger which utilizes an adaptive turn ratio scheme to achieve a wide output voltage range and high efficiency. The high frequency transformer of the LLC converter of the proposed strategy has an adaptively changed turn ratio through the auxiliary control circuit. As a result, an optimized converter design with high magnetizing inductance is possible, while minimizing conduction and turn-off losses and providing a regulated voltage gain to properly charge the lithium ion battery. For a step-by-step explanation, operational principle and optimal design considerations of the proposed converter are illustrated in detail. Finally, the effectiveness of the proposed strategy is verified through various experimental results and efficiency analysis based on prototype 300W Li-ion battery charger and battery pack.