• International Journal of Computer Science & Network Security
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• v.21 no.9
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• pp.11-18
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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.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.2
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• pp.142-148
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• 2005

This paper proposes a cell age model for Penicillium chrysogenum fed-batch cultivation to supply a qualitative insight into morphology-associated dynamics. The average ages of the segregated cell populations, such as growing cells, non-growing cells and intact productive cells, were estimated by this model. A combined model was obtained by incorporating the aver-age ages of the cell sub-populations into a known but modified segregated kinetic model from literature. For simulations, no additional effort was needed for parameter identification since the cell age model has no internal parameters. Validation of the combined model was per-formed by 20 charges of industrial-scale penicillin cultivation. Meanwhile, only two charge-dependent parameters were required in the combined model among approximately 20 parameters in total. The model is thus easily transformed into an adaptive model for a further application in on-line state variables prediction and optimal scheduling.

• Korean Journal of Culture and Social Issue
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• v.21 no.3
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• pp.299-315
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• 2015

This study examines correlations among factors that reportedly affect adjustment to military life: self esteem, locus of control,, social support and stress coping strategies. The study also attempts to validate the structural model to enhance understanding of the process of adjusting to the military life. The subjects of the study were 447 listed soldiers from private to sergeant currently stationed and serving in an army post in Gangwon-Do, Korea. The following tools were used for this study. Based on self-inventory questionnaires, evaluations were made regarding self esteem, locus of control, social support, stress management, adaptation to military life. Reliability of each criterion was evaluated based on reliability examination, correlations among parameters were analyzed, and the structural equation model was validated to verify the research model. The results of the study can be summarized as follows. First, internal control and self esteem have significant positive influence on social support and stress coping. Second, internal control and self esteem affect adjusting to military life through social support and active coping, two factors mediated in this study to act as parameters between self-esteem and internal control and military adaption. This study emphasizes intervention such as establishment of a social support system and training for taking necessary actions as limitations of studies dealing with internal traits and military adaptation. Since the subjects of this study were chosen from an army based in a single location for convenience' sake, it may be difficult to generalize the results to analyze the entire military.

• The Journal of Internal Korean Medicine
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• v.35 no.4
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• pp.505-518
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• 2014

Objectives: This study was undertaken to investigate the effects of Gugijagami-bang (GGB) in a hyperlipidemic animal model induced by a high-fat diet using diverse biological methods. Methods: This study was to determine whether fractionated GGB extracts inhibit reactive oxygen species (ROS) and nitric oxide (NO) in RAW 264.7 cells. Hyperlipidemia was induced by a high-fat diet fed for 6 weeks. Total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride, liver function and histologic change of liver were measured after oral administration of GGB. Results: 1. DPPH scavenging bow performance was increased in a concentration-dependent manner by GGB. 2. Compared to the control group, NO production (%) and ROS production (%) were decreased significantly by GGB. 3. Total-cholesterol, LDL-cholesterol, triglyceride were decreased significantly by GGB. 4. HDL cholesterol increased more than the control group, but not significantly. 5. In histopathologic examination, fatty liver (hepatic steatosis) was inhibited, almost no rounds of fat were observed in the liver. Conclusions: GGB would appear effective in the prevention and treatment of atherosclerosis, ischemic heart disease, other cardiovascular diseases caused by hyperlipidemia.

• The Journal of Internal Korean Medicine
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• v.35 no.2
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• pp.119-132
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• 2014

Objectives : This study was undertaken to investigate the effects of Samulhwalhyeol-tang (SM) in a hyperlipidemic animal model induced by a high-fat diet using diverse biological methods. Methods : This study was to determine whether fractionated EtOH extracts of SM inhibit reactive oxygen species (ROS) and nitric oxide (NO) in RAW 264.7 cells. Hyperlipidemia was induced by a high-fat diet fed for 6 weeks. Total cholesterol, LDL cholesterol, HDL cholesterol, triglyceride, glucose, liver function, cholesterol gene revelation control efficiency, and histologic change of liver were measured after oral administration of SM. Results : 1. Compared to the control group, ROS production (%) and NO production (%) were decreased significantly by SM. 2. Total cholesterol, LDL cholesterol, triglyceride were decreased significantly by SM. 3. HDL cholesterol was increased significantly by SM. 4. Rats' body weight and glucose were decreased significantly by SM. 5. AST, ALP were decreased significantly by SM. 6. In histopathologic examination, fatty liver and fiver fibrosis were inhibited, almost eliminated as round of fat was observed in the liver. Conclusions : SM would appear that effective in the prevention and treatment of atherosclerosis, ischemic heart disease, other cardiovascular diseases, fatty liver and nephrotic syndrome caused by hyperlipidemia.

• The Journal of Internal Korean Medicine
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• v.32 no.1
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• pp.1-9
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• 2011

Objectives : This study was performed in order to investigate the effect of Panax notoginseng(SCG) on phenylhydrazine (PHZ)-induced hemolytic anemia in rats. Materials and Methods : Rats were divided equally into 3 groups (Normal, Control, SCG). Anemic model rats (Control, SCG) were induced by the treatment of PHZ (40mg/kg/day, i.p.) for 3 days. Red blood cell, hemoglobin, reticulocyte count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration were determined on days 0, 4, 7 and 10. Body weight was investigated on days 0, 2, 4, 6, 8, 10 and weight of spleen was measured on day 10. Results : In the SCG group, significantly higher levels of RBC was found on day 4 and higher concentration of Hb on days 4, 7 and 10. Furthermore, reticulocyte count was dramatically lower on day 10 compared to the control group. Conclusions : These results suggest that SCG may be beneficial in the treatment of hemolytic anemia.

• The Journal of Internal Korean Medicine
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• v.26 no.1
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• pp.156-168
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• 2005

Objective : The purpose of this research is to examine the effects of Pinelliae Rhizoma (PR) extract on immune cells and cytokines in ovalbumin (OVA)-induced asthmatic mice. Methods : In vivo, C57BL/6 mice were sensitized and handicapped by OVA for 12 weeks. During this experiment, the one group was then treated with PR extract for the 8 weeks (3 times per week) and analyzed by ELISA and flow cytometer. Results : In vivo, there were significant decreases in eosinophils, IL-4, IL-5, IL-13, IgE in BALF (bronchoalveolar lavage fluid) compared with that of control group. However, $IFN-{\gamma}$ in BALF of GS group increased significantly, compared with that of control group. Additionally, the population of $CD3e^-/CCR3^+,\;CD69^+/CD3e^+,\;IgE^+/B220^+,\;CD11b^+/Gr-l^+$ cells in the PR group decreased, compared with that of control group. Conclusion : The results of this study support a role for PR as an effective treatment for asthma in its experimental success in significantly decreasing inflammation and asthma reactions, and in increasing $IFN-{\gamma}$, which helps prevent such reactions.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.239-242
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• 1996

A model following control system(MFCS) can give general output signals following desired ones. In previous studies, a method of nonlinear MFCS was proposed by S.Okubo[1]. In this paper, the method of nonlinear MFCS will be extended to discrete time nonlinear systems. It is easy to extend the method to discrete time systems. But in the case .gamma.=1 discrete time systems, the proof becomes difficult, because the transfer function from f(v(k)) to v(k) can't be a positive real function. In this case, to ensure that internal states are stable, a new criterion is proposed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.437-442
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• 2000

An alternative inverse feedback structure for adaptive active control of periodic noise is introduced for systems with nonminimum phase cancellation path. To obtain the inverse model of the nonminimum phase cancellation path, the cancellation path model can be factorized into a minimum phase term and a maximum phase term. The maximum phase term containing unstable zeros makes the inverse model unstable. To avoid the instability, we alter the inverse model of the maximum phase system into an anti-causal FIR one. An LMS predictor estimates the future samples of the noise, which are necessary for causality of both anti-causal FIR approximation for the stable inverse of the maximum phase system and time-delay existing in the cancellation path. The proposed method has a faster convergence behavior and a better transient response than the conventional FX-LMS algorithms with the same internal model control structure since a filtered reference signal is not required. We compare the proposed methods with the conventional methods through simulation studies.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.9
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• pp.1461-1467
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• 2001

This paper proposes a new approach for the ant-swing control of overhead cranes. The proposed control consists of a model-based anti-swing control scheme and a practical path planning scheme. The anti-swing control scheme is designed based on the Lyapunov stability theorem; the proposed control does not require the usual constraints of small load mass, small load swing, slow hoisting speed, and small hoisting distance, but guarantees asymptotic stability while keeping all internal signals bounded. The path planning scheme is designed based on the concepts of minimum-time control and anti-swing control; the proposed path planning generates near-minimum-time trajectories independently of hoisting speed and distance. The effectiveness of the proposed control is shown by computer simulation.