• Industrial Engineering and Management Systems
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• v.3 no.1
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• pp.1-11
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• 2004

This paper proposes a new algorithm for determining an optimal control input for production systems. In many production systems, completion time should be planned within the due dates by taking into account precedence constraints and processing times. To solve this problem, the max-plus algebra is an effective approach. The max-plus algebra is an algebraic system in which the max operation is addition and the plus operation is multiplication, and similar operation rules to conventional algebra are followed. Utilizing the max-plus algebra, constraints of the system are expressed in an analogous way to the state-space description in modern control theory. Nevertheless, the formulation of a system is currently performed manually, which is very inefficient when applied to practical systems. Hence, in this paper, we propose a new algorithm for deriving a state-space description and determining an optimal control input with several constraint matrices and parameter vectors. Furthermore, the effectiveness of this proposed algorithm is verified through execution examples.

• Biomolecules & Therapeutics
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• v.5 no.1
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• pp.8-11
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• 1997

The odor theory (기미론) has been defined as the Nature (기) and the Taste(미) of traditional herbal medicine to find the logic in treatment of various diseases by them. There is a strong possibility these Na1ures of the drug can be categorized according to yin (음) and yang (음). There is a neutral Nature which does not fit into one of these four categories. To understand the Natures of traditional herbal drugs in modern scientific approaches, changes in rectal temperature of rats have been measured at 0,30, 60, 90 min after a 10 g/Kg oral administration each of 34 different drugs. Following the classification of the four Natures of drugs, only the temperatures of warm group at 30, 60, and 90 min were elevated significantly from the control and the rest groups. Following a modified classification of 3 groups such as cold and cool, warm and hot, and neutral Nature, changes in temperatures after administration of Hot and Warm drugs were also increased significantly from the control (P<0.01). Thus, the measurement of rectal temperature can be a tool to define the Nature (기) of traditional herbal drugs, but the modified classification is another way to do.

• Journal of Families and Better Life
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• v.21 no.5
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• pp.25-40
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• 2003

Since Korea open her ports to the West, she had undergone a great change under the alien influences both on the macro-social and micro-social aspects. This study aims to review the korean housing, corresponding with the everyday life, during the period of transition between the 1876 - 1910 and to interpret its process of modernization and the meaning of modernity. With regards to understand the holistic human relationship and place pf living through history, this study takes the Nobert Elias' Civilization Theory as a theoretical basis. References were therefore, made to various records of foreign missionary at the time, with respect not only to macro sociological changes but also to changes of everyday life. It is of course to take physical and structural aspects of housing architecture into consideration. These works, thus, led to presuming the housing culture of said period. In order to investigate modern character of korean housing, distinctively represented by spatial structure, considerations were made to various architectural examples according to the social and residential status both in urban and rural area. As a results, this paper came to the remarks as follows; 1. It is understood, that the process of modernization is a part of the process of civilization as synthetic process. It is integrated with the change of socio-cultural aspects and everyday life. 2. Korean housing in the said period shows various different residential status and grade of civilization according to the social status as well as economical status. Modern housing was not in general yet. 3. Housing for high classes and middle classes in Seoul shows a tendency of assimilation and imitation after western model. But some examples within the housing of high classes represent its own modernity, that is based on the rationalism and equalization 4. In the housing of lower classes, it was very far from the benefits of civilization. It could analogize from the immature control of disgrace, from undevelopment of individual territory and from uncultivation of rationality in the housing space.

• Steel and Composite Structures
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• v.45 no.4
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• pp.535-546
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• 2022

The memory response of nonlocal systematical formulation size-dependent coupling of viscoelastic deformation and thermal fields for piezoelectric materials with dual-phase lag heat conduction law is constructed. The method of the matrix exponential, which constitutes the basis of the state-space approach of modern control theory, is applied to the non-dimensional equations. The resulting formulation together with the Laplace transform technique is applied to solve a problem of a semi-infinite piezoelectric rod subjected to a continuous heat flux with constant time rates. The inversion of the Laplace transforms is carried out using a numerical approach. Some comparisons of the impacts of nonlocal parameters and time-delay constants for various forms of kernel functions on thermal spreads and thermo-viscoelastic response are illustrated graphically.

• Proceedings of the KIEE Conference
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• 1999.07b
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• pp.712-714
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• 1999

Ball-balancing control systems are ideal to demonstrate the design and hardware implementation Procedures of optimal controllers based on modern control theory. This paper presents the design of an $H_2$ optimal controller based on the generalized plant model of the ball-balancing system. The problem of balancing a metal ball on the midpoint of a beam is ultimately related to a regulating problem. So, the designed controller is correspond to this problem. The controller was experimented by DSP(digital signal processing) equipments and simulated by MATLAB. The performance of controller was verified through the experiments.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.4
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• pp.299-305
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• 2013

The complexity and severe nonlinearity of multi-machine power systems make it difficult to design a control input for voltage regulation using modern control theory. This paper presents a model-based PID control scheme for the regulation of the bus voltage to a desired value. To this end, a fourth-order linear system is constructed using input and output data obtained using the TSAT (Transient Security Assessment Tool); the input is assumed to be applied to the grid through the STATCOM (STATic synchronous COMpensator) and the output from the grid is a bus voltage. On the basis of the model, it is identified as to which open-loop poles of the system make the response to a step input oscillatory. To reduce this oscillatory response effectively, a model-based PID control is designed in such a way that the oscillatory poles are no longer problematic in the closed loop. Simulation results show that the proposed PID control dampens the response effectively.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.8
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• pp.1104-1110
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• 2012

The inverted pendulum system is a common, interesting control problem that involves many basic elements of control theory. In the early, controls of stabilization for the inverted pendulum system were used classical methods like PD, PID controller. In recently, however, control methods based on modern and intelligent control theory are widely applied. The fuzzy logic controller which is often used in nonlinear control is a little too hard to design due to increasing fuzzy rules rapidly if the given system like inverted pendulum has many state variables. Also, in case the state variables are divided into two parts, two fuzzy controllers are needed in the control system. In this paper, the authors propose FCSC(Fuzzy Controller based on State variables Combination) that reorganized into two new signals depending on the physical meaning of the four state variables of the inverted pendulum system. The proposed method is applied to the inverted pendulum system and simulations are accomplished to illustrate the control performance.

• Proceedings of the KIEE Conference
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• 1990.07a
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• pp.356-360
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• 1990

This paper is an application of Modern control Theory to the control of a current-source inverter (CSI) fed Induction Motor Drive System. A Linear Quadratic-Gaussian (LQG) scheme is developed, in which the Kalman Filter is tuned for high robustness by a method due to Doyle and Stein(8). The design is carried out for a sample system and the robustness by analysis and computer simulation.

• Korean Management Science Review
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• v.10 no.1
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• pp.107-125
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• 1993

Modern telecommunication switching systems are SPC(Stored Program Control) machines handling voice, data and other kinds of traffic, in an environment which tends to be fully digital switching and transmission. The throughput of such systems is determined by the real time capacity of its centralized or distributed control processors and by the traffic capacity of the switching network. Designers must verify the traffic and call processing capacity of the switching system and check its performance under traffic load before it is put into service. Verification of traffic and call processing capacity of switching systems is one of the problems treated by teletraffic studies ; teletraffic studies are based on stochastic process, queueing theory, simulations and other quantitative methods of decision making. This study suggests the general methodology to evaluate the throughput and performance of the ISDN switching system. TDX-10 ISDN switching system are employed to give illustrative examples of the methodologies discussed in this study.

• Journal of Korean Institute of Industrial Engineers
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• v.13 no.2
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• pp.17-34
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• 1987

Modern telecommunication switching systems are SPC (Stored Program Control) machines handling voice, data and other kinds of traffic, in an environment which tends to be fully digital switching and transmission. The throughput of such systems is determined by the real time capacity of its centralized or distributed control processors and by the traffic capacity of the switching network. Designers must verify the traffic and call processing capacity of the switching system and check its performance under traffic load before it is put into service. Verification of traffic and call processing capacity of switching systems is one of the problems treated by teletraffic studies; teletraffic studies are based on stochastic process, queueing theory, simulations and other quantitative methods of decision making. This paper reviews the general methodologies to evaluate the throughput and performance of the digital switching system. TDX-10, which is a fully digital switching system under development in ETRI, is employed to give illustrative examples of the methodologies discussed in this paper.