• Title/Summary/Keyword: variable stability system

Search Result 377, Processing Time 0.027 seconds

A Meta-Analysis of the Variables Related with Social Support for Female Marriage Immigrants (여성결혼이민자의 사회적 지지와 관련 변인 메타분석)

  • Lee, Eun-Joo;Jun, Mi-Kyung
    • Journal of Families and Better Life
    • /
    • v.31 no.5
    • /
    • pp.125-141
    • /
    • 2013
  • This research aims to integrate study results through a meta-analysis of previous studies on the variables related with social support for female marriage immigrants. Based on the results, this study established the foundation of an integrated social support system for female marriage immigrants which considers both the functional perspective and structural perspective of social support, and suggested plans for an efficient support system. All social support was positively associated with female marriage immigrants marriage life, child-rearing behavior and attitude, reduction of stress and depression and psychological stability. In relation to the effect size of each variable related with all social support, the marriage variable had the biggest relationship with it, followed by the parenting variable, the psychological variable and the stress variable in that order. With reference to the relationship with related variables according to the sub-domain of social support, from the structural perspective, spousale support showed a high relationship with the marriage variable and the stress variable. It was also especially, very highly related with the marriage variable. In addition, a married woman's family support and expert support had an intermediate relationship with the marriage variable, and the husband's family support and friend support had a low relationship with it. From the functional perspective, material support had a very high relationship with the marriage variable, whereas it had a low relationship with the stress variable and the psychological variable. Emotional support was also highly related with marriage variable, but showed an intermediate or low relationship with the psychological variable and the stress variable. On the other hand, informational support displayed an intermediate relationship with the stress variable and the psychological variable, and a high relationship with the marriage variable. Lastly, evaluative support had a high relationship with the marriage variable and the psychological variable. Based on these results, this study proposed plans for an integrated social support system as follows. First, education ought to be provided for the spouses, and support for marital adjustment should be offered. Second, there plans should be made for continuous bonding with the family of origin, and support should be given to address changes in awareness of the relationship with the husband's parents. Third, it is required to revitalize the local community and self-help groups, and provide the female marriage immigrants with opportunities to participate in social activities.

Simultaneous identification of damage in bridge under moving mass by Adjoint variable method

  • Mirzaee, Akbar;Abbasnia, Reza;Shayanfar, Mohsenali
    • Smart Structures and Systems
    • /
    • v.21 no.4
    • /
    • pp.449-467
    • /
    • 2018
  • In this paper, a theoretical and numerical study on bridge simultaneous damage detection procedure for identifying both the system parameters and input excitation mass, are presented. This method is called 'Adjoint Variable Method' which is an iterative gradient-based model updating method based on the dynamic response sensitivity. The main advantage of proposed method is inclusion of an analytical method to augment the accuracy and speed of the solution. Moving mass is a model which takes into account the inertia effects of the vehicle. This interaction model is a time varying system and proposed method is capable of detecting damage in this variable system. Robustness of proposed method is illustrated by correctly detection of the location and extension of predetermined single, multiple and random damages in all ranges of speed and mass ratio of moving vehicle. A comparison study of common sensitivity and proposed method confirms its efficiency and performance improvement in sensitivity-based damage detection methods. Various sources of errors including the effects of measurement noise and initial assumption error in stability of method are also discussed.

Controller design of variable structure system with an integral-augmented sliding surface for uncertain MIMO systems (적분 슬라이딩 면을 갖는 다변수 가변 구조 제어기 설계)

  • 이정훈;문건우;고종선;이대식;이주장;윤명중
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1993.10a
    • /
    • pp.1206-1212
    • /
    • 1993
  • In this paper, an variable structure system with an integral-augmented sliding surface is designed for the improved robust control of a uncertain multi-input multi-output(MIMO) system subject to the persistent disturbances. To effectively remove the reaching phase problems, the integral augmented sliding surface is defined, then for its design, the eigenstructure assignment technique is introduced. To guarantee the designed performance againts the persistent disturbance, the stabilizing control for multi-input system is also designed. The stability of the global system and performance robustness are investigated. The example will be given for showing the usefulness of algorithm.

  • PDF

Implementation of Auto-reclosing Relay Algorithm based on Multi-Agent System using EMTP-MODELS (EMTP-MODELS를 이용한 Multi-Agent System 기반의 자동 재폐로 계전 알고리즘 구현)

  • Lee, Byung-Hyun;Yeo, Sang-Min;Lee, You-Jin;Kim, Chul-Hwan;Sung, No-Kyu
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.57 no.1
    • /
    • pp.8-13
    • /
    • 2008
  • This paper presents auto-reclosing algorithms with reference to power system stability based on MAS(Multi-Agent System). And this paper shows auto-reclosing algorithms considering power system stability. It includes the variable dead time, optimal reclosing, sequential reclosing, emergency extended equal-area criterion(EEEAC) algorithm, and modified EEEAC algorithm. This paper divides Auto-reclosing algorithms into respectively agents according to their tasks. A separated agent is merely a software entity that is situated in some environment and is able to autonomously react to changes in the environment. And all the simulations in this parer were tested by EMTP MODELS.

Application of Fuzzy-PSS to KEPCO power system and stability enhancement (퍼지형 전력계통안정화제어기의 실계통 적용 및 안정도 향상)

  • Choi, Kyung-Sun;Lee, Dong-In;Lee, Kwang-Sik
    • Proceedings of the KIEE Conference
    • /
    • 1997.07c
    • /
    • pp.1052-1055
    • /
    • 1997
  • The importance of dynamic stability of power system is increasing as the excitation system using static type are greatly enlarged. There are several types of PSS at Present, Elements of PSS consist of Notch filter, lead-lag filter, washout limiter which are variable. The existing power system has a difficulty in determining the optimal PSS parameters whenever PSS is installed. And it is recommended to retune PSS parameters periodically because system characteristics change due to aging. In this paper, intelligent PSS using fuzzy concept is introduced to get over difficulties mentioned above. The usefulness of fuzzy-type PSS was verified by applying FPSS to KEPCO power system. Generally, the voltage regulation deteriorates if conventional PSS is applied because supplementary signal is added into AVR summing point to damp Power oscillation. In this paper this problem is solved by AVR limiter and fuzzy members tuning.

  • PDF

A Study on the Modeling and Analysis of Chatter in Turning Operation (선반가공시 채터 모델링과 분석에 관한 연구)

  • 윤문철;조현덕;김성근;김영국;조희근
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.10 no.4
    • /
    • pp.76-83
    • /
    • 2001
  • In this study, the static and dynamic characteristics of turning process was modelled and the analytic realization of regen-erative chatter mechanism was discussed. In this regard, we have discussed on the comparative assessment of recursive times series modeling algorithms that can represent the machining process and detect the abnormal machining behaviors in precision turning operation. In this study, simulation and experimental work were performed to show the malfunction behaviors. For this purpose, new Recursive Extended Instrument Variable Method(REIVM) was adopted for the on-line system identification and monitoring of a machining process. Also, we can apply REIVE algorithms in real process for the detection of chatter frequency and dynamic property and analyze the stability lobe of the system by changing a parameter of cutting dynamics in regenerative chatter mechanics, if it is stable or unstable, Also, The stability lobe of chatter was analysed.

  • PDF

Multi-function Control of Hydraulic Variable Displacement Pump with EPPR Valve (전자비례감압밸브를 이용한 가변용량형 유압펌프의 다기능 제어)

  • Jung, Dong-Soo;Kim, Hyong-Eui;Kang, E-Sok
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.14 no.6
    • /
    • pp.160-170
    • /
    • 2006
  • If hydraulic pump controlled by mechanical type regulator has more than one control function, the construction of regulator will be very complicated and control performance falls drastically. It is difficult to have more than one control function for hydraulic pump controlled by electronic type hydraulic valve due to the inconsistency of controllers. This paper proposes a multi-function control technique which controls continuously flow, pressure and power by using EPPR(Electronic Proportional Pressure Reducing) valve in swash plate type axial piston pump. Nonlinear mathematical model is developed from the continuity equation for the pressurized control volume and the torque balance for the swash plate motion. To simplify the model we make the linear state equation by differentiating the nonlinear model. A reaction spring is installed in servo cylinder to secure the stability of the control system. We analyze the stability and disturbance by using the state variable model. Finally, we review the control performances of flow, pressure and power by tests using PID controller.

Sampled-Data Observer-Based Decentralized Fuzzy Control for Nonlinear Large-Scale Systems

  • Koo, Geun Bum;Park, Jin Bae;Joo, Young Hoon
    • Journal of Electrical Engineering and Technology
    • /
    • v.11 no.3
    • /
    • pp.724-732
    • /
    • 2016
  • In this paper, a sampled-data observer-based decentralized fuzzy control technique is proposed for a class of nonlinear large-scale systems, which can be represented to a Takagi-Sugeno fuzzy system. The premise variable is assumed to be measurable for the design of the observer-based fuzzy controller, and the closed-loop system is obtained. Based on an exact discretized model of the closed-loop system, the stability condition is derived for the closed-loop system. Also, the stability condition is converted into the linear matrix inequality (LMI) format. Finally, an example is provided to verify the effectiveness of the proposed techniques.

A Study on Time-Varying Sliding Regime of VSC System (가변구조제어계의 시변 슬라이딩 레짐에 관한 연구)

  • Kim, Joong-Wan;Lee, Man-Hyung
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.6 no.2
    • /
    • pp.30-39
    • /
    • 1989
  • Variable structure control (VSC) systems control the state vectors using sliding regime (SR) constructed switching logic, switching plane and control law. Saturation function switching logic is used to improve the drawback which occurs in traditional sign function switching logic. Switching plane with time-varying parameter is proposed to improve the drawback which occurs in switching plane with constant parameter and it is suggested the control law which has time-varying parameter. The stability of VSC system controlled by proposed time-varying SR is discussed, and the good control behavior was shown through computer simulation using proposed SR.

  • PDF

A variable structure controller with a PI-type reaching law (PI 형 도갈법칙을 가지는 가변구조 제어)

  • Chun, Kyung-Han;Lee, Yun-Jung;Choi, Bong-Yeol
    • Journal of Institute of Control, Robotics and Systems
    • /
    • v.3 no.3
    • /
    • pp.214-218
    • /
    • 1997
  • We propose a VSC(Variable Structure Controller) with a PI-type reaching law. In General, conventional VSCs with a reaching law including a discontinuous term have the chattering problem, and thus the system may be unstable due to the disregarded high frequency dynamics in the modeling process. To resolve this problem, the PI-type reaching law is proposed in this paper. The proposed reaching law makes it easy to determine the reaching dynamics as well as the reaching time by utilizing the 2nd-order system analysis. Furthermore, since the discontinous term is not involved in the reaching law, the chattering is considerably reduced. To show the effectiveness of the proposed scheme, the stability of the proposed system is proved by Lyapunov method and the computer simulations are performed for the Ball Balance System.

  • PDF