• Title/Summary/Keyword: Internal Model Control

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Determinants of Health Promoting Behavior of Middle Aged Women in Korea (한국 중년 여성의 건강증진 행위 예측 모형 구축)

  • 이숙자;박은숙;박영주
    • Journal of Korean Academy of Nursing
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    • v.26 no.2
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    • pp.320-336
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    • 1996
  • Health promoting behaviors of an individual are affected by various variables. Recently, there has been a growing concern over important health problems of the middle aged women. Physiological changes in the middle aged women and their responsibility for family care can result in physical and psychological burden experienced by middle aged women. This study was designed to test Pender's model and thus purpose a model that explains health promoting behaviors among middle-aged women in Korea. The hypothetical model was developed based on the Pender's health promoting model and the findings from past studies on women's health. Data were collected by self-reported questionnaires from 863 women living in Seoul, between 20th, April and 15th, July 1995. Data were analyzed using descriptive statistics and correlation analysis. The Linear Structural Relationship(LISREL) modeling process was used to find the best fit model which assumes causal relationships among variables. The results are as follows : 1. The Overall fit of the hypothetical model to the data was good expect chi-square value(GFI=.96, AGFI=.91, RMR=.04). 2. Paths of the model were modified by considering both its theoretical implication and statistical significance of the parameter estimates. Compared to the hypothetical model, the revised model has become parsimonious and had a better fit to the data expect chi-square value(GFI=.95, AFGI= .92. RMR=.04). 3. Some of modifying factors, especially age, occupation, educational levels and body mass index (BMI) are revealed significant effects on health promoting behaviors. 4. Some of cognitive-perceptual factors, especially internal health locus of control, self-efficacy and perceptive health status are revealed significant effects on health promoting behaviors. 5. All predictive variables of health promoting behaviors, especially age, occupation, educational levels, body mass index(BMI), internal health locus of control, self-efficacy & perceptive health status are explained 20.0% of the total variance in the model.

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The Effects of Epimedii Herba on a Hypothyroidism Rat Model induced by PTU(6-Propyl, 2-thiouracil) (음양곽(淫羊藿)이 실험적으로 유발된 갑상선 기능저하증 동물모델에 미치는 영향과 안전성)

  • Hong, Min-Jin;Lee, Byung-Choel;Ahn, Young-Min;Ahn, Se-Young
    • Journal of Pharmacopuncture
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    • v.14 no.4
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    • pp.13-22
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    • 2011
  • Objectives: The symptoms of hypothyroidism are fatigue, cold intolerance, arthralgia, muscle cramps, dry skin and etc. Although hypothyroidism is a relatively common endocrinical disease, we do have many difficulties treating it effectively. The symptoms of hypothyroidism are similar to those of Yang-deficiency in Oriental medicine. Epimedii Herba is a popular herb that has the effect of tonifying the kidney and strengthening Yang in Oriental medicine. In this study, we investigated the therapeutic effects of Epimedii Herba on a hypothyroidism rat model induced by PTU(6-Propyl, 2-thiouracil). Methods: 24 two-month-old Spargue-Dawley(SD) rats were divided into 4 groups: 1) normal(n=6), 2) PTU-induced hypothyroidism control(n=6), 3) hypothyroidism rat treated with Epimedii Herba(n=6), 4) hypothyroidism rat treated with levothyroxine(n=6). PTU was administered for 4 weeks, Epimedii Herba and levothyroxine was administered for 2 weeks after PTU was initiated for a total duration of 2 week. At the end of the experiment, blood samples from all the rats were taken from their hearts and were analyzed. Results: In comparison with normal group, the PTU-induced control group significantly showed hypothyroidism with low T3, T4 and high TSH. In Epimedii Herba group, T4 was significantly increased(p<0.05). There was no significant difference in TSH between the Epimedii Herba treatment group and the control group. And no significant differences were observed in biochemical labs and weight between the Epimedii Herba group and the control group. Conclusions: These results suggest that Epimedii Herba could help thyroid cells to produce thyroid hormones. And no significant side effects related with Epimedii Herba were found, suggesting that it is safe to administer. According to these results, Epimedii Herba may be a safe alternative medicine for hypothyroidism.

NEW MODELING AND CONTROL OF AN ASYMMETRIC HYDRAULIC ACTIVE SUSPENSION SYSTEM

  • Kim, Wanil;Sangchul Won
    • 제어로봇시스템학회:학술대회논문집
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    • 1998.10a
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    • pp.490-495
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    • 1998
  • In this paper an asymmetric hydraulic actuator which consists of single acting cylinder and servo valve is modeled for a quarter car active suspension system. This model regards the force as an internal state rather than a control input. The control input of the model is the sum of oil flows that pass through the valve's orifices. The resulting dynamic equation in the state space ap-pears a feedback connection of a nominal linear time in-variant term with a nonlinear bounded uncertain block. Since this model makes it possible to eliminate the force control phase, analysis and controller design are made straightforward and simple. Well known LQR method is then applied. Simulation and test rig experiment show the effectiveness of this approach in modeling and control.

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Multiaxial ratcheting assessment of Z2CND18.12N steel using modified A-V hardening rule

  • Xiaohui Chen;Yang Zhou;Wenwu Liu;Xu Zhao
    • Steel and Composite Structures
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    • v.49 no.1
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    • pp.1-17
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    • 2023
  • Based on Ahmadzadeh-Varvani hardening rule (A-V model), multiaxial ratcheting effect of Z2CND18.12N austenitic stainless steel is simulated by ABAQUS with user subroutine UMAT. The results show that the predicted results of the origin multiaxial A-V model are lower than the experimental data, and it is difficult to control ratcheting strain rate. In order to improve the predicted capability of A-V model, the A-V model is modified. In this study. Moreover, under the assumption of the von Mises yield criterion and normal plasticity flow rule, we develop a numerical algorithm of plastic strain with the improved model to implement the finite element calculation of the model. Internal iteration in the numerical algorithm was implemented with the Euler backward method, which calculated the trial strain for each equilibrium iteration using the consistent tangent matrix. With a user subroutine, the proposed model is programmed into ABAQUS for a user - executable version. By simulating the uniaxial ratcheting of a round bar made of Z2CND18.12N austenitic stainless steel, we observe that the predicted results simulated by ABAQUS with UMAT are compared with the experimental data. The predicted results of the improved multiaxial A-V model are consistent well with the experimental data.

Design of Generalized Minimum Variance Controllers for Nonlinear Systems

  • Grimble Michael J.
    • International Journal of Control, Automation, and Systems
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    • v.4 no.3
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    • pp.281-292
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    • 2006
  • The design and implementation of Generalized Minimum Variance control laws for nonlinear multivariable systems that can include severe nonlinearities is considered. The quadratic cost index minimised involves dynamically weighted error and nonlinear control signal costing terms. The aim here is to show the controller obtained is simple to design and implement. The features of the control law are explored. The controller obtained includes an internal model of the process and in one form is a nonlinear version of the Smith Predictor.

The Effects of Cuscuta Semen on a Hypothyroidism Rat Model induced by Propylthiouracil(PTU) (토사자가 PTU로 유발된 갑상선기능저하증 Rat에 미치는 영향)

  • Kang, Ji-Suck;Park, Sung-Hwan;Han, Su-Ryun;Ahn, Young-Min;Ahn, Se-Young;Lee, Byung-Cheol
    • The Journal of Internal Korean Medicine
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    • v.31 no.3
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    • pp.425-436
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    • 2010
  • Objectives : Hypothyroidism is a relatively common endocrinologic disease, especially among older women. Western medical doctors treat hypothyroidism with levothyroxine, however there are several side effects, including thyrotoxicosis, atrial fibrillation, osteoporosis, etc. Therefore, traditional Korean medicine(TKM) offers an appealing alternative therapy for hypothyroidism. In this study, Cuscuta Semen was used to analyze its possible effect on a hypothyroidism rat model induced by propylthiouracil(PTU). Methods : 24 two-month-old Sprague-Dawley(SD) rats were divided into 4 groups: normal (n=6), PTU-induced hypothyroidism control(n=6), hypothyroidism rat treated with Cuscuta Semen (n=6), and hypothyroidism rat treated with levothyroxine(n=6). PTU was administered for 4 weeks, Cuscuta Semen and levothyroxine was administered 2 weeks after PTU was initiated for a total duration of 2 weeks. Blood samples from all the rats were taken from their hearts and analyzed. Results : When compared to the normal group, the PTU-induced control group showed significantly lower $T_4$, $T_3$ levels and significantly higher TSH level, which is indicative of hypothyroidism. The Cuscuta Semen group had significantly higher $T_4$ and significantly lower TSH than the control group(p<0.05). There was no significant difference in biochemical labs and weight between the Cuscuta Semen and control groups. Conclusions : These results suggest that Cuscuta Semen could be effective in increasing thyroid hormone production, and be powerful enough to affect the hypothalamus-pituitary-thyroid axis. Also, no adverse effects related with Cuscuta Semen were found, suggesting that it is relatively safe to administer. In conclusion, it seems that Cuscuta Semen is a safe alternative medicine for hypothyroidism.

On the Development of the Generic CFCS for Engineering Level Simulation of the Surface Ship (공학수준 수상함 지휘무장통제체계 범용 모델 개발방안 연구)

  • Jung, Young-Ran;Han, Woong-Gie;Kim, Cheol-Ho;Kim, Jae-Ick
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.3
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    • pp.380-387
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    • 2011
  • In this paper, we considered the authoritative representation of Command and Fire Control System(CFCS) for the surface ship that was the engineering level model to develop system specifications and to analyze operational concepts on the concept design phase and to analyze military requirements, effectiveness and performance for the system. The engineering level model of CFCS can be used in simulation independently of the surface ship's type, and also it takes reuse, interoperability, and extension into consideration. The detailed sub-models, internal and external data interface, data flow among each sub-model, sensor and weapon models about the engineering level model of CFCS was defined. It was verified via engineering level simulations according to the V&V process.

H Observer Design for Detecting Internal Oil Leakage in a Hydraulic Cylinder (유압실린더 내부 누유 검출을 위한 H 관측기 설계)

  • Jee, Sung Chul;Kang, Hyungjoo;Lee, Mun-Jik;Li, Ji-Hong
    • Journal of Institute of Control, Robotics and Systems
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    • v.22 no.2
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    • pp.117-125
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    • 2016
  • This paper presents the internal oil leakage detection problem for a hydraulic double-rod cylinder. We represent the dynamics of the hydraulic cylinder as a convex combination of linear equations. To detect oil leakage, we propose a model-based fault detection observer design scheme. The observer is designed to be robust against disturbance. Sufficient design conditions are derived in the form of linear matrix inequalities. A numerical example is provided to verify the proposed techniques.

External Magnetic Field of Journal Bearing with Twined Solenoid

  • Zhang, Yanjuan;Wang, Jianmei;Li, Decai
    • Journal of Magnetics
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    • v.22 no.2
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    • pp.291-298
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    • 2017
  • In this paper, the distribution of internal magnetic induction intensity of oil-film bearing twined solenoids was proposed. The magnetic field was generated by solenoids and magnetized bearing. The magnetized bearing was simplified as solenoid model. The mathematical model of magnetic induction intensity at any point of finite solenoid was deduced. Through experiment method, the distribution of the internal magnetic induction intensity of oil-film bearing and the magnetizing current formula of bearing was obtained. Further, the magnetic induction intensity distribution of magnetization bearing was solved successfully. The results showed that the magnetic induction was a second-degree parabola with open upwards along the axial plane and the distribution of magnetic induction intensity was opposite to the rule of magnetic induction intensity generated by solenoids. In addition, the magnetic flux density increased linearly with the increase of current.

Design of Multivariable PID Controllers: A Comparative Study

  • Memon, Shabeena;Kalhoro, Arbab Nighat
    • International Journal of Computer Science & Network Security
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    • v.21 no.8
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    • pp.212-218
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    • 2021
  • The Proportional Integral Derivative (PID) controller is the most popular industrial controller and more than 90% process industries use this controller. During the past 50 years, numerous good tuning methods have been proposed for Single Input Single Output Systems. However, design of PI/PID controllers for multivariable processes is a challenge for the researchers. A comparative study of three PID controllers design methods has been carried-out. These methods include the DS (Direct Synthesis) method, IMC (Internal model Control) method and ETF (Effective Transfer Function) method. MIMO PID controllers are designed for a number of 2×2, 3×3 and 4×4 process models with multiple delays. The performance of the three methods has been evaluated through simulation studies in Matlab/Simulink environment. After extensive simulation studies, it is found that the Effective Transfer Function (ETF) Method produces better output responses among two methods. In this work, only decentralized methods of PID controllers have been studied and investigated.