• Title/Summary/Keyword: Control strategies

Search Result 2,427, Processing Time 0.04 seconds

Evolving Neural Network for Realtime Learning Control (실시간 학습 제어를 위한 진화신경망)

  • 손호영;윤중선
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 2000.10a
    • /
    • pp.531-531
    • /
    • 2000
  • The challenge is to control unstable nonlinear dynamic systems using only sparse feedback from the environment concerning its performance. The design of such controllers can be achieved by evolving neural networks. An evolutionary approach to train neural networks in realtime is proposed. Evolutionary strategies adapt the weights of neural networks and the threshold values of neuron's synapses. The proposed method has been successfully implemented for pole balancing problem.

  • PDF

A Comparison of Smoking Control Strategies in Korea and the United States

  • Lee Chung Yul;Ham Ok Kyung;Hong Yoon Mi
    • Journal of Korean Academy of Nursing
    • /
    • v.34 no.8
    • /
    • pp.1379-1387
    • /
    • 2004
  • The purpose of this study was to compare smoking control strategies between Korea and the United States. Korea and other developing countries may learn from the experience of the United States in dealing with the growing epidemic of cigarettes. In particular, smoking control objectives, structures, laws and regulations, funds, programs and activities, research, and surveillance systems were compared. The comparison was conducted at the federal, states/provincial, and county levels of the two countries. The data were collected through various governmental websites, contact with people directly, and a literature review. Based on the comparison, seven recommendations for smoking control strategies were made primarily for Korea.

A Study on the Relationship between Korean Company's Quality Strategy and Management Control System (국내기업의 품질전략과 경영통제시스템간의 상호관계에 관한 연구)

  • Shin, Hong-Chul;Kim, Ran
    • Journal of Korean Society for Quality Management
    • /
    • v.22 no.2
    • /
    • pp.1-19
    • /
    • 1994
  • There have been few studies which deal with the linkage between a corporate strategy and its management control system. Especially, no empirical study has been done in Korea to figure out if management control systems of Korean companies are designed and implemented to support companies' objectives and strategies. Based on the survey results of 68 companies we empirically tested if Korean companies are implementing appropriate control systems to complement their Quality strategies. Two representative quality strategies were classified into ECL(Economic Conformance-Level) and ZD(Zero-Defect) strategy. It was measured by a set of seven attitude questions addressing whether the managers adhered to ECL strategy or ZD Quality strategy. In addition, we checked if there is a difference m the level of commitment to the quality depending on the adoption of quality cost system. The results partly support the second hypothesis and regarding the first analysis we can conclude that there is not a strong linkage between Korean companies' ZD strategy and their management control systems.

  • PDF

Reduction of seismic pounding effects of base-isolated RC highway bridges using MR damper

  • Sheikh, M.N.;Xiong, J.;Li, W.H.
    • Structural Engineering and Mechanics
    • /
    • v.41 no.6
    • /
    • pp.791-803
    • /
    • 2012
  • Significant structural damages due to pounding between adjacent superstructures of multi-span reinforced concrete (RC) highway bridges have been observed in past earthquakes. Different methods have been proposed in the literature to mitigate the adverse seismic pounding effects. This paper presents an analytical investigation on the use of magnetorheological (MR) dampers in reducing seismic pounding effects of base-isolated multi-span RC highway bridges. It has been observed that MR damper can effectively reduce the seismic pounding effect. Three control strategies (passive off, passive on, and bang bang control) of MR damper have been investigated. Although all the control strategies are found to be effective, bang bang control has been observed to be the most effective.

Multiple Decoupling Current Control Strategies for LCL Type Grid-Connected Converters Based on Complex Vectors under Low Switching Frequencies

  • Liu, Haiyuan;Shi, Yang;Guo, Yinan;Wang, Yingjie;Wang, Wenchao
    • Journal of Power Electronics
    • /
    • v.19 no.4
    • /
    • pp.1034-1044
    • /
    • 2019
  • In medium-voltage and high-voltage high-power converters, the switching devices need to operate at a low switching frequency to reduce power loss and increase the power capacity. This increases the delay of the signal sampling and PWM. It also makes the cross-couplings of the d-q current components more severe. In addition, the LCL filter has three cross-coupling loops and is prone to resonance. In order to solve these problems, this paper establishes a complex vector model of an LCL type grid-connected converter. Based on this model, two multiple decoupling current control strategies with passive damping / notch damping are proposed for the LCL type grid-connected converter. The proposed strategies can effectively eliminate the cross-couplings of the converter, achieve independent control of the d-q current components, expand the stable region and suppress the resonance of the LCL filter. Simulation and experimental results verify the correctness of the theoretical analysis and the feasibility of the proposed strategies.

Implementation and Improvement Strategies of Scientific Techniques in the Assessement Criteria of KS Certification (KS 인증 심사기준에서 과학적 기법의 적용 및 개선 방안)

  • Choi, Sung-Woon
    • Proceedings of the Safety Management and Science Conference
    • /
    • 2010.04a
    • /
    • pp.181-188
    • /
    • 2010
  • The research presents the implementation and improvement strategies of scientific methodologies and techniques in the audit criteria of KS certification. The paper discusses the establishment of management strategy and quality policy by the alignment of BSC or policy deployment, the effective handling methodologies of control plan based on SPC, and the traceability of calibration uncertainty and MSA, etc.

  • PDF

The Effects of Scaffolding Instruction by Zone of Proximal Development on Motivated Learning Strategies and Academic Achievement (Vygotsky의 근접발달이론에 의한 사회적 상호작용수업이 동기화학습전략 및 학업성취도에 미치는 효과)

  • HWANG, Hee-Sook;KANG, Jin-Min
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.16 no.1
    • /
    • pp.35-49
    • /
    • 2004
  • The purpose of this study is to examine the effects of scaffolding instruction on motivated learning strategies and academic achievement. Subjects of this study were 96 middle school first grade students in Busan, who were randomly assigned to two experimental group and one control group. The one experimental group had received scaffolding instruction by teacher, and the other experimental group had received scaffolding instruction by the interaction of peers. Control group were given traditional lessons only by the method of lecture. Students were given English Academic Achievement Test, Motivated Strategies of Learning Questionnaire. T test and ANOVA were used to analyze date. The results of this study showed that scaffolding instruction by ZPD turned out to have a positive influence on motivated learning strategies and academic achievement.

Wastewater Treatment Plant Control Strategies

  • Ballhysa, Nobel;Kim, Soyeon;Byeon, Seongjoon
    • International journal of advanced smart convergence
    • /
    • v.9 no.4
    • /
    • pp.16-25
    • /
    • 2020
  • The operation of a wastewater treatment plant (WWTP) is a complex task which requires to consider several aspects: adapting to always changing influent composition and volume, ensuring treated effluents quality complies with local regulations, ensuring dissolved oxygen levels in biological reaction tanks are sufficient to avoid anoxic conditions etc. all of it while minimizing usage of chemicals and power consumption. The traditional way of managing WWTPs consists in having employees on the field measure various parameters and make decisions based on their judgment and experience which holds various concerns such as the low frequency of data, errors in measurement and difficulty to analyze historical data to propose optimal solutions. In the case of activated sludge WWTPs, parts of the treatment process can be automated and controlled in order to satisfy various control objectives. The models developed by the International Water Association (IWA) have been extensively used worldwide in order to design and assess the performance of various control strategies. In this work, we propose to review most recent WWTP automation initiatives around the world and identify most currently used control parameters and control architectures. We then suggest a framework to select WWTP model, control parameters and control scheme in order to develop and benchmark control strategies for WWTP automation.

A study on the determinants of job stress responses of the staff nurses (일반 간호사의 직무 스트레스 반응에 대한 결정 요인)

  • Kim, Jeong-Hee;Park, Sung-Ae
    • Journal of Korean Academy of Nursing Administration
    • /
    • v.9 no.2
    • /
    • pp.217-232
    • /
    • 2003
  • Purpose : This paper was attempted to identify the job stress related factors among the staff nurses and to provide the basic data concerning development of stress management program focused on hospitals. Method : The subjects were 309 staff nurses at two general hospitals in Seoul. Data were collected with self-reported questionnaires and analyzed by SPSS-PC+10.0 for descriptive analysis, ANOVA, stepwise multiple regression, factor analysis. Results : The subjects exhibit significantly highest level of 'the participation in decision making factor'. The mean score of 'control coping strategies' was higher than 'avoid coping strategies'. The mean scores of social support and stress responses were high. The main factor that affected the stress responses was 'the job characteristic factor' and it was explained 23.0% out of the total variance of the stress responses. Also, it would be explained 42.6% out of the total variance of the stress responses with 'the control coping strategies, work overload factors, social support, and participation in decision making factors'. Conclusion: For developing the hospital- focused stress management program for staff nurses, 'the participation in decision making factors' and 'the job characteristics' should be considered. Also, the organizational efforts and supports should be required to support and use of 'control coping strategies' of nurses

  • PDF

Stability Analysis using Dynamic Model of Two Industrial Robots Handling a Single Object (두개의 ROBOT이 한물체를 다룰때의 Dynamic Model을 이용한 Stability Analysis)

  • Kim, Kab-Il
    • Proceedings of the KIEE Conference
    • /
    • 1991.07a
    • /
    • pp.809-812
    • /
    • 1991
  • Two control strategies are proposed for two arm robots; i.e. position-position control and position-force control. For the proof of these control strategies, the stability analysis is conducted with robot dynamics included. First, the closed form dynamic equation of the robot is derived, then it is transformed into the operational space for further analysis. Finally, Liapunov method is applied to the dynamic equation in operational space.

  • PDF