• 제목/요약/키워드: Process disturbances

검색결과 247건 처리시간 0.025초

사이토카인과 우울증 (Cytokines and Depression)

  • 김용구
    • 생물정신의학
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    • 제15권3호
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    • pp.175-185
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    • 2008
  • Accumulating evidence has suggested the existence of reciprocal communication between immune, endocrine, and neurotransmitter system. Cytokine hypothesis of depression implies that increased pro-inflammatory cytokine such as -1, IL-6, IL-12, TNF-${\alpha}$, and IFN-${\gamma}$ in major depression, acting neuromodulators, play a key role in the mediation of behavioral, neuroendocrine, and neurochemical disturbances in depression. Concerning the relation between cytokines and serotonin metabolism, pro-inflammatory cytokines have profound effects on the metabolism of brain serotonin through the enzyme indoleamine-2,3-dioxygenase(IDO) that metabolizes tryptophan, the precursor of 5-HT to neurodegenerative quinolinate and neuroprotective kynurenate. The neurodegeneration process is reinforced by the neurotoxic effect of the hypercortisolemia during depression. From this perspective, it is possible that efficacy of antidepressants in the treatment of depression may, at least in part, rely on downregulation of pro-inflammatory cytokine synthesis. So, the use of cytokine synthesis inhibitors or cytokine antagonists may be a new treatment approach in depression. However, at present the question whether cytokines play a causal role in the onset of depression or are mere epiphenomena sustaining depressive symptoms remains to be elucidated. Nevertheless, cytokine hypothesis has created new perspectives in the study of psychological and pathophysiological mechanism that are associated with major depression, as well as the prospect for developing a new generation antidepressants.

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Nonlinear Excitation Control Design of Generator Based on Multi-objective Feedback

  • Chen, Dengyi;Li, Xiaocong;Liu, Song
    • Journal of Electrical Engineering and Technology
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    • 제13권6호
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    • pp.2187-2195
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    • 2018
  • In order to realize the multi-objective control of single-input multi-output nonlinear differential algebraic system (NDAS) and to improve the dynamic characteristics and static accuracy, a design method of nonlinear control with multi-objective feedback (NCMOF) is proposed, the principium of this method to arrange system poles, as well as its nature to coordinate dynamic characteristics and static accuracy of the system are analyzed in detail. Through NCMOF design method, the multi-objective control of the system is transformed into linear space, and then it is effectively controlled under the nonlinear feedback control law, the problem to balance all control objectives caused by less input and more output of the system thus is solved. Applying NCMOF design method to generator excitation system, the nonlinear excitation control law with terminal voltage, active power and rotor speed as objective outputs is designed. Simulation results show that NCMOF can not only improve the dynamic characteristics of generator, but also damp the mechanical oscillation of a generator in transient process. Moreover, NCMOF can control the terminal voltage of the generator to the setting value with no static error under typical disturbances.

Effects of Vitamin D on Blood Pressure and Endothelial Function

  • Min, Bokyung
    • The Korean Journal of Physiology and Pharmacology
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    • 제17권5호
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    • pp.385-392
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    • 2013
  • Vitamin D deficiency is prevalent, primarily due to limited sun exposure, which may be observed in urban areas, or as a result of modern lifestyles. Common myths about vitamin D persist, including that it is mostly obtained from the diet and is only essential for bone and mineral homeostasis. Nonetheless, advances in biomedical science suggest that vitamin D is a hormone that is integral to numerous physiologic functions in most cells and tissues. Therefore, abnormal vitamin D levels may contribute to health disturbances. A number of recent reports on potential associations between vitamin D deficiency and cardiovascular disease have highlighted its role in this system. A focus over the previous decade has been to better understand the mechanisms behind vitamin D regulation and the pathophysiology associated with suboptimal vitamin D levels. Vitamin D deficiency is highly associated with the incidence of cardiovascular diseases, even when considering other well-known risk factors. In this process, the renin-angiotensin system is disrupted, and hypertension and endothelial dysfunction contribute to the risk of cardiovascular disease. Likewise, clinical outcomes upon the normalization of vitamin D levels have been investigated in different patient populations. It makes sense that vitamin D supplementation to improve vitamin D status among vitamin D-deficient individuals could be useful without requiring a sudden lifestyle change. This manuscript provides a brief overview of vitamin D metabolism and the vitamin D receptor. It also summarizes the current clinical research relating to vitamin D supplementation and its effects on hypertension and endothelial dysfunction in cardiovascular medicine.

Decision Feedback Equalization Receiver for DS-CDMA with Turbo Coded Systems

  • Chompoo, T.;Benjangkaprasert, C.;Sangaroon, O.;Janchitrapongvej, K.
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1132-1136
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    • 2005
  • In this paper, adaptive equalizer receiver for a turbo code direct sequence code division multiple access (DSCDMA) by using least mean square (LMS) adaptive algorithm is presented. The proposed adaptive equalizer is using soft output of decision feedback adaptive equalizer (DFE) to examines the output of the equalizer and the Log- maximum a posteriori (Log-MAP) algorithm for the turbo decoding process of the system. The objective of the proposed equalizer is to minimize the bit error rate (BER) of the data due to the disturbances of noise and intersymbol interference (ISI)phenomenon on the channel of the DS-CDMA digital communication system. The computer program simulation results shown that the proposed soft output decision feedback adaptive equalizer provides a good BER than the others one such as conventional adaptive equalizer, infinite impulse response adaptive equalizer.

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실험을 통한 모션제어기의 특성비교 (Characteristics Comparison of Motion Controllers through Experiments)

  • 정승현;왕준;한창욱;박정일
    • 제어로봇시스템학회논문지
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    • 제14권11호
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    • pp.1094-1102
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    • 2008
  • Through the motion control experiment using Industrial Emulator(Model 220 by ECP), the performance comparison of three kinds of controllers such as PID, RIC and LQR was carried out. It was shown that RIC has the best performance in the presence of disturbances such as step one, sinusoidal one and Coulomb friction for the rigid body. LQR using feedback state variables has the best tracking performance far the flexible body. The performance of PID controller is low compared to other controllers, but the design process is simple. The most advanced controller is LQR. In order to attenuate disturbance, an additional state observer should be used to estimate it, making more complex control system. RIC lies between PID and LQR in view of complexity of design. Even though RIC is not complicated, it has good disturbance rejection ability and less tracking error. By considering these aspects, the RIC is suggested as high precision controller to be used in motion control system.

신경염증과 정신질환 (Neuroinflammation and Psychiatric Illness)

  • 송후림;이화영;심세훈;권영준
    • 생물정신의학
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    • 제23권1호
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    • pp.12-17
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    • 2016
  • Neuroinflammation is one of important allostatic loads contributory to the various psychiatric illness. It is mediated mainly by glial cells, which produce both proinflammatory and antiinflammatory cytokines, and the balance of them determines the inflammatory process in the central nervous system. S100 calcium-binding protein B, which is used as an inflammatory marker is also released by glial cells. In the molecular level, oxidative stress contributes to the neuroinflammation. Their disturbances have been revealed in the psychiatric illness and related with the dysregulation of the glutamatergic and monoaminergic systems. There is a possibility to use them as disease markers. The approach for inflammation using antiinflammatory drugs and antioxidants could be connected to the development of disease-modifying treatments. Also, a searching examination about specific subtypes who are vulnerable to inflammation in the patients is required to confirm their efficacy clearly.

스카라로보트의 적응-슬라이딩모드 제어에 관한 연구 (A Study on Adaptive-Sliding Mode Control of SCARA Robot)

  • 윤대식
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1999년도 추계학술대회 논문집 - 한국공작기계학회
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    • pp.148-153
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    • 1999
  • In this paper, it is proposed the adaptive-sliding mode control technique which is new approach to implement the robust control of industrial robot manipulator with external disturbances and parameter uncertainties. Over the past decade, the design of advanced control systems for industrial robotic manipulators has been a very active area of research and two major design categories have emerged. Sliding mode control is a well-known technique for robust control of uncertain nonlinear systems. The robustness of sliding model controllers can be shown in continuous time, but digital implementation may not preserve robustness properties because the sampling process limits the existence of a true sliding mode. Adaptive control algorithm is designed by using the principle of the model reference adaptive control method based upon the hyperstability theory. The proposed control scheme has a simple structure is computationally fast and does not require knowledge of the complex dynamic model or the parameter values of the manipulator or the payload. Simulation results how that the proposed method not only improves the performance of the system but also reduces the chattering problem of sliding mode control. Consequently, it is expected that the new adaptive sliding mode control algorithm will be suited for various practical applications of industrial robot control system.

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보행자모델 시뮬레이션을 활용한 건강검진센터 행위자 효율성 평가에 관한 연구 (A Study on the Agent Efficiency Evaluation of Health Examination Centers Using Pedestrian Model Simulation)

  • 윤소희;권현주;김석태
    • 한국멀티미디어학회논문지
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    • 제21권4호
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    • pp.499-512
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    • 2018
  • The application of analytical techniques for the rational determination of problems arising from management science and corporate management. In a way that is the opposite of the repair plan that can predict accurate results is increasing utilization of the complex-based analysis methodology. In this study, we examined the application of physical space and the methodological utilization of the pedestrian model analysis that applied the simulation to the Health Checkup Center. The conclusions are as follows. First, the spatial analysis and measurement for empirical research has confirmed that the efficiency assessment through the pedestrian model simulation can lead to an objective evaluation. Second, it seems to be able to reduce the queue through a change in the number of services of the low-pressure and the hearing laboratory, the recovery room with a high proportion of male disturbances and relatively long use time. The third, the spatial density analysis and the time required to reduce the density change in comparative analysis, and the spatial layout changes, the increase in the capacity of 80 people, approximately 16 minutes to shorten the process duration.

골관절염 여성노인의 아픔경험에 대한 현상학적 연구 (Pain of Elderly Women with Osteoarthritis)

  • 신재신;안혜경;김향미;유연자;김경희;정인경;이윤미
    • 대한간호학회지
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    • 제31권2호
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    • pp.180-193
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    • 2001
  • The purpose of this study was to determine the meaning of the pain and experiences of elderly women with osteoarthritis, by adopting Colaizzi′s phenomenological method. The participants were 7 elderly women over the age of 65. They were selected using a theoretical sampling technique. The Data was collected by in-depth and open-ended interviews from Dec. 1. 1999. to Feb, 28. 2000. The length of the interviews varied from 120 minutes to 180 minutes. Data was recorded and analyzed by a constant comparative method. From the data, significant statements were extracted and then organized into 48 themes, which resulted in 15 clusters of themes and 6 categories. The final descriptions turned out to be valid through the interviewee′ validation process. Essential themes of the pain experiences emerged : "physical discomfortness(disturbances)", "negative state of mind", "influence of the death", "positive change in life", "Cause of pain perceived", and "change of their personal relationships". From these results, it was found that elderly women need nursing care based on a deep understanding of pain, and a reflection on their past is imperative to overcome their given situations. In conclusion, it is suggested that the care givers provide more support to solve the problems experienced by the elderly. Thus the researchers expect to provide understanding of older people and give basic data of holistic care for them.

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디스크 스피닝 성형기의 유압 및 제어시스템 설계 (Design of Hydraulic & Control System for the Disc Spinning Machine)

  • 강정식;박근석;강이석
    • 한국정밀공학회지
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    • 제19권9호
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    • pp.157-165
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    • 2002
  • The design of hydraulic & control system has been developed for the disc spinning machine. The hydraulic system has been designed in the overall system including the vertical & horizontal slide fur spinning works which are controlled by hydraulic servo valves in right & left side, and the clamping slide for holding & pressing blank material in center during spinning process. Based on the design concept of this hydraulic system, model test experiments for hydraulic servo control system is tested to conform confidence and applying possibility. The control system is introduced with the fuzzy-sliding mode controller for the hydraulic force control reacting force as a disturbance, because a fuzzy controller does not require an accurate mathematical model for the generation of nonlinear factors in the actual nonlinear plant with unknown disturbances and a sliding controller has the robustness & stability in mathematical control algorithm. We conform that the fuzzy-sliding mode controller has a good performance in force control for the plant with a strong disturbance. Also, we observe that a steady state error of the fuzzy-sliding mode controller can be reduced better than those of an another controllers.