• 제목/요약/키워드: self-controlled feedback

검색결과 42건 처리시간 0.027초

역진자형 자주로보트의 2차원 평면에서 궤도주행제어에 관한 연구 (Trajectory Tracking Control of the Wheeled Inverse Pendulum Type Self - Contained Mobile Robot in Two Dimensional Plane)

  • 하윤수;유영호;하주식
    • Journal of Advanced Marine Engineering and Technology
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    • 제17권5호
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    • pp.44-53
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    • 1993
  • In this paper, we discuss on the control algorithm to make the wheeled inverse pendulum type mobile robot move in two dimensional plane. The robot considered in this paper has two independently driven wheels in same axel which suport and move it-self, and is assumed to have the fyro type sensor to know the inclination algle of the body and rotary encoders to know wheel's rotation angular velocity. The control algorithm is divided into three parts. The first part is for the posture and velocity control for forward-backward direction, the second is the steering control, and the last part is for the control of total system to track the given trajectory. We handle the running velocity control of the robot as part of the posture control to keep the balance because the posture relates deeply with the velocity and can be controlled by the velocities of the wheels. The control problem is analyzed as the tracking control, and the controller is realized with the state feedback and feed-forward of the reference velocity. Constructing the control system which contained one intergrator in forward path, we also realized the control system without observer for the estimation of the accumulated errors in the inclination angle of the body. To prevent the robot from being unstable state by sudden variation of the reference velocity when it starts and stops, or changes velocity, the reference velocity of which acceleration is slowly changing, is ordered to the robot. To control its steering, we give the different reference velocities for both wheels which are calculated from the desired angular velocity of the body. Finally, we presents the experimental results of the experimental robot Yamabico Kurara in which the proposed control algorithm had been implemented.

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An MMIC VCO Design and Fabrication for PCS Applications

  • Kim, Young-Gi;Park, Jin-Ho
    • Journal of Electrical Engineering and information Science
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    • 제2권6호
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    • pp.202-207
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    • 1997
  • Design and fabrication issues for an L-band GaAs Monolithic Microwave Integrated Circuit(MMIC) Voltage Controlled Oscillator(VCO) as a component of Personal Communications Systems(PCS) Radio Frequency(RF) transceiver are discussed. An ion-implanted GaAs MESFET tailored toward low current and low noise with 0.5mm gate length and 300mm gate width has been used as an active device, while an FET with the drain shorted to the source has been used as the voltage variable capacitor. The principal design was based on a self-biased FET with capacitive feedback. A tuning range of 140MHz and 58MHz has been obtained by 3V change for a 600mm and a 300mm devices, respectively. The oscillator output power was 6.5dBm wth 14mA DC current supply at 3.6V. The phase noise without any buffer or PLL was 93dB/1Hz at 100KHz offset. Harmonic balance analysis was used for the non-linear simulation after a linear simulation. All layout induced parasitics were incorporated into the simulation with EEFET2 non-linear FET model. The fabricated circuits were measured using a coplanar-type probe for bare chips and test jigs with ceramic packages.

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Servo control strategy for uni-axial shake tables using long short-term memory networks

  • Pei-Ching Chen;Kui-Xing Lai
    • Smart Structures and Systems
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    • 제32권6호
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    • pp.359-369
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    • 2023
  • Servo-motor driven uniaxial shake tables have been widely used for education and research purposes in earthquake engineering. These shake tables are mostly displacement-controlled by a digital proportional-integral-derivative (PID) controller; however, accurate reproduction of acceleration time histories is not guaranteed. In this study, a control strategy is proposed and verified for uniaxial shake tables driven by a servo-motor. This strategy incorporates a deep-learning algorithm named Long Short-Term Memory (LSTM) network into a displacement PID feedback controller. The LSTM controller is trained by using a large number of experimental data of a self-made servo-motor driven uniaxial shake table. After the training is completed, the LSTM controller is implemented for directly generating the command voltage for the servo motor to drive the shake table. Meanwhile, a displacement PID controller is tuned and implemented close to the LSTM controller to prevent the shake table from permanent drift. The control strategy is named the LSTM-PID control scheme. Experimental results demonstrate that the proposed LSTM-PID improves the acceleration tracking performance of the uniaxial shake table for both bare condition and loaded condition with a slender specimen.

Implementation of Self-adaptive System using the Algorithm of Neural Network Learning Gain

  • Lee, Seong-Su;Kim, Yong-Wook;Oh, Hun;Park, Wal-Seo
    • International Journal of Control, Automation, and Systems
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    • 제6권3호
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    • pp.453-459
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    • 2008
  • The neural network is currently being used throughout numerous control system fields. However, it is not easy to obtain an input-output pattern when the neural network is used for the system of a single feedback controller and it is difficult to obtain satisfactory performance with when the load changes rapidly or disturbance is applied. To resolve these problems, this paper proposes a new mode to implement a neural network controller by installing a real object for control and an algorithm for this, which can replace the existing method of implementing a neural network controller by utilizing activation function at the output node. The real plant object for controlling of this mode implements a simple neural network controller replacing the activation function and provides the error back propagation path to calculate the error at the output node. As the controller is designed using a simple structure neural network, the input-output pattern problem is solved naturally and real-time learning becomes possible through the general error back propagation algorithm. The new algorithm applied neural network controller gives excellent performance for initial and tracking response and shows a robust performance for rapid load change and disturbance, in which the permissible error surpasses the range border. The effect of the proposed control algorithm was verified in a test that controlled the speed of a motor equipped with a high speed computing capable DSP on which the proposed algorithm was loaded.

관상동맥중재술을 받은 환자를 위한 스마트 프로그램이 질병관련 지식, 건강행위와 삶의 질에 미치는 효과: 비무작위 대조군설계 (The Effects of Smart Program for Patients Who Underwent Percutaneous Coronary Intervention (SP-PCI) on Disease-Related Knowledge, Health Behavior, and Quality of Life: A Non-Randomized Controlled Trial)

  • 이주은;이해정
    • 대한간호학회지
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    • 제47권6호
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    • pp.756-769
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    • 2017
  • Purpose: To identify the effects of a smart program for the patients who underwent percutaneous coronary intervention (SP-PCI) on coronary disease-related knowledge, health behaviors, and quality of life. Methods: A nonequivalent control group with a non-synchronized design was utilized and 48 participants (experimental=22, control=26) were recruited from a university hospital in Gyeongsang area from May to December, 2016. The 12-week SP-PCI consisted of self-study of health information using smart phone applications (1/week), walking exercise (>5/week) using smart band, feedback using Kakao talk (2/week), and telephone counseling (1/week). Patients in the control group received usual care from their primary health care providers and a brief health education with basic self-management brochure after the PCI. Data were analyzed using the SPSS 21.0 program through descriptive statistics, $x^2$ test, and t-test. Results: After the 12-week SP-PCI, the experimental group showed higher levels of coronary disease-related knowledge (t=2.43, p=.019), heart-related health behaviors (t=5.96, p<.001), regular exercise (Z=-4.47, p<.001), and quality of life-MCS (t=3.04, p=.004) and showed lower levels of stress (Z=-3.53, p<.001) and sodium intake (t=-4.43, p<.001) than those in the control group. There were no significant group differences in medication adherence and food intake in total energy, lipids, and cholesterol. Conclusion: The suggested SP-PCI provided easy access and cost-effective intervention for patients after PCI and improved their knowledge of the disease, performance of health behaviors, and quality of life. Further study with a wider population is needed to evaluate the effects of SP-PCI on disease recurrence and quality of life for patients after PCI.

임상판단모델에 근거한 디브리핑 적용이 임종간호 학습성과에 미치는 효과: 비무작위 대조시험설계 (Effect of Debriefing Based on the Clinical Judgment Model on Simulation Based Learning Outcomes of End-of-Life Care for Nursing Students: A Non-Randomized Controlled Trial)

  • 정경인;최자윤
    • 대한간호학회지
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    • 제47권6호
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    • pp.842-853
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    • 2017
  • Purpose: This study was conducted to identify effects of debriefing based on the clinical judgment model for nursing students on their knowledge, skill performance, clinical judgment, self-confidence and learner satisfaction during simulation based end-of-life care (ELC) education. Methods: Simulation based ELC education was developed in six steps as follows: selection of learning subjects and objects, development of learning tools, a trial run of simulation-based education, students' skill training, and evaluators' training. Forty-eight senior nursing students (25 in the experimental group and 23 in the control group) participated in the simulation-based ELC education using a high-fidelity simulator. Debriefing based on the clinical judgment was compared with the usual debriefing. Results: ANCOVA showed that there were differences in knowledge (F=4.81, p=.034), skill performance (F=68.33, p<.001), clinical judgment (F=18.33, p<.001) and self-confidence (F=4.85, p=.033), but no difference in satisfaction (t=-0.38, p=.704) between the experimental and control groups. Conclusion: This study found that debriefing based on the clinical judgement model is effective for supporting nursing students for reflecting on clinical judgment and improving their diverse competencies in complex clinical settings such as ELC.

Improving Work Functioning and Mental Health of Health Care Employees Using an E-Mental Health Approach to Workers' Health Surveillance: Pretest-Posttest Study

  • Ketelaar, Sarah M.;Nieuwenhuijsen, Karen;Bolier, Linda;Smeets, Odile;Sluiter, Judith K.
    • Safety and Health at Work
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    • 제5권4호
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    • pp.216-221
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    • 2014
  • Background: Mental health complaints are quite common in health care employees and can have adverse effects on work functioning. The aim of this study was to evaluate an e-mental health (EMH) approach to workers' health surveillance (WHS) for nurses and allied health professionals. Using the waiting-list group of a previous randomized controlled trial with high dropout and low compliance to the intervention, we studied the pre- and posteffects of the EMH approach in a larger group of participants. Methods: We applied a pretest-posttest study design. The WHS consisted of online screening on impaired work functioning and mental health followed by online automatically generated personalized feedback, online tailored advice, and access to self-help EMH interventions. The effects on work functioning, stress, and work-related fatigue after 3 months were analyzed using paired t tests and effect sizes. Results: One hundred and twenty-eight nurses and allied health professionals participated at pretest as well as posttest. Significant improvements were found on work functioning (p = 0.01) and work-related fatigue (p < 0.01). Work functioning had relevantly improved in 30% of participants. A small meaningful effect on stress was found (Cohen d = .23) in the participants who had logged onto an EMH intervention (20%, n = 26). Conclusion: The EMH approach to WHS improves the work functioning and mental health of nurses and allied health professionals. However, because we found small effects and participation in the offered EMH interventions was low, there is ample room for improvement.

심혈관질환 위험인자를 가진 중소규모 사업장 남성 근로자의 모바일헬스 앱 활용 건강파트너십 프로그램의 효과: 무작위 실험연구 (Effects of a Health Partnership Program Using Mobile Health Application for Male Workers with Cardiovascular Risk Factors in Small and Medium Enterprises: A Randomized Controlled Trial)

  • 김은진;황선영
    • 대한간호학회지
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    • 제54권1호
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    • pp.44-58
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    • 2024
  • Purpose: This study aimed to apply a health partnership program using commercially available mobile health apps to improve cardiovascular risk factors in male employees and verify its effectiveness. Methods: Using a randomized control group pretest-posttest design, male employees with cardiovascular risk factors from five small and medium-sized workplaces were randomly assigned to an experimental group (n = 32) and a control group (n = 31). The experimental group was encouraged to use three mobile health apps for 12 weeks to acquire the necessary cardiovascular disease-related information and practice strengthening training, walking, and diet management appropriate to their level. They also received feedback on their weekly activities and motivational text messages from health partners. Hypotheses were tested using the SPSS WIN 22.0. Results: The experimental group showed a significant difference compared to the control group in terms of their perception of mobile health app (p < .05), self-efficacy for exercise and diet, self-management partnership, and cardiovascular disease prevention health behavior (p < .001). In particular, there were significant decreases in the body mass index, ratio, serum fasting blood sugar, total cholesterol, and triglyceride in the experimental group (p < .001); however, there was no significant difference in high-density lipoprotein-cholesterol. Conclusion: Intervention using mobile apps based on partnership with health managers is effective in improving the objective cardiovascular risk index in male employees; therefore, such intervention should be continuously used as a useful lifestyle modification strategy in the workplace.

설계과목 프로그래밍 수업을 중심으로 루브릭 시스템 정착을 위한 연구 (A Study for Encouragement of Rublic System in Designing with Programming Classes)

  • 조미경;박현석
    • 한국컴퓨터정보학회논문지
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    • 제14권11호
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    • pp.81-90
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    • 2009
  • 기간 및 환경에 통제를 받는 수동적인 초중등교육과정을 마치고 자율과 책임이 수반되는 대학교육으로 전환은 매우 혼란스러울 수밖에 없다. 이때 대학교육은 정형화된 교과과정의 주입식 반복 교육에서 벗어나 적성의 적합성과 창의적이고 주도적인 학습을 전개할 수 있도록 교육시스템 제반이 구축되어 있어야 한다. 예로 공과대학 프로그래밍 교과는 가르치는 교수의 교육방식에 따라 학습자들의 교육성과는 매우 밀접한 상관관계를 갖게 된다. 과거 이론위주의 수업방식에서 실습 중심으로의 교육전환은 좋은 성과를 거둘 수 있다. 또한 창의적이고 자기주도적 학습을 활발하게 계발할 수 있도록 인지 중심의 교수주체평가제에서 수행중심 평가제 도입의 필요성이 대두됨에 따라 이를 위해 루브릭(Rublic) 시스템을 적용하였다. 평가항목 및 평가기준 그리고 평가점수 등의 평가지침이 공개된 상태에서 모든 학습자 또는 다수로 구성된 교수평가를 피드백 하는 방식이다. 시스템적용 후 학습자의 학업성취도(GPA: Grade Point Average)가 향상되었는지 공인된 설문을 통해 알아보고 향상되었다면 시스템 정착을 위해 앞으로 어떠한 노력이 필요한지를 살펴보았다.

Systematical Analysis of Cutaneous Squamous Cell Carcinoma Network of microRNAs, Transcription Factors, and Target and Host Genes

  • Wang, Ning;Xu, Zhi-Wen;Wang, Kun-Hao
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권23호
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    • pp.10355-10361
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    • 2015
  • Background: MicroRNAs (miRNAs) are small non-coding RNA molecules found in multicellular eukaryotes which are implicated in development of cancer, including cutaneous squamous cell carcinoma (cSCC). Expression is controlled by transcription factors (TFs) that bind to specific DNA sequences, thereby controlling the flow (or transcription) of genetic information from DNA to messenger RNA. Interactions result in biological signal control networks. Materials and Methods: Molecular components involved in cSCC were here assembled at abnormally expressed, related and global levels. Networks at these three levels were constructed with corresponding biological factors in term of interactions between miRNAs and target genes, TFs and miRNAs, and host genes and miRNAs. Up/down regulation or mutation of the factors were considered in the context of the regulation and significant patterns were extracted. Results: Participants of the networks were evaluated based on their expression and regulation of other factors. Sub-networks with two core TFs, TP53 and EIF2C2, as the centers are identified. These share self-adapt feedback regulation in which a mutual restraint exists. Up or down regulation of certain genes and miRNAs are discussed. Some, for example the expression of MMP13, were in line with expectation while others, including FGFR3, need further investigation of their unexpected behavior. Conclusions: The present research suggests that dozens of components, miRNAs, TFs, target genes and host genes included, unite as networks through their regulation to function systematically in human cSCC. Networks built under the currently available sources provide critical signal controlling pathways and frequent patterns. Inappropriate controlling signal flow from abnormal expression of key TFs may push the system into an incontrollable situation and therefore contributes to cSCC development.