• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.74.3-74
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• 2001

This paper proposes a nonlinear adaptive controller based on back-stepping method for tracking reference substrate concentration by manipulating dilution rate in a continuous baker´s yeast cultivating process in stirred tank bioreactor. Control law is obtained from Lyapunov control function to ensure asymptotical stability of the system. The Haldane model for the specific growth rate depending on only substrate concentration is used in this paper. Due to the uncertainty of specific growth rate, it has been modified as a function including the unknown parameter with known bounded values. The substrate concentration in the bioreactor and feed line are measured. The deviation from the reference is observed when the external disturbance such as the change of the feed is introduced to the system ...

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2724-2729
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• 2010

This paper presents a method of constructing the sequential digital systems over finite fields. We assign all elements in finite fields to digit codes using mathematical properties of finite fields. Also, we discuss the operational characteristics and properties of the building block T-gate which is used to implement the sequential digital systems over finite fields. Then, we implemented sequential digital systems without feed-back. The sequential digital systems without feed-back is constructed as following steps. First, we assign the states in state-transition diagram to state digit codes, then obtain the state function and predecessor table which is explaining the relationship between present states and previous states. Next, we obtained the next-state function from state function and predecessor table. Finally we realize the circuit using T-gate and decoder. The proposed method is more efficiency and systematic than previous method.

• Journal of Information Processing Systems
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• v.13 no.4
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• pp.703-715
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• 2017

Mammogram images are sensitive in nature and even a minor change in the environment affects the quality of the images. Due to the lack of expert radiologists, it is difficult to interpret the mammogram images. In this paper an algorithm is proposed for a computer-aided diagnosis system, which is based on the wavelet based adaptive sigmoid function. The cascade feed-forward back propagation technique has been used for training and testing purposes. Due to the poor contrast in digital mammogram images it is difficult to process the images directly. Thus, the images were first processed using the wavelet based adaptive sigmoid function and then the suspicious regions were selected to extract the features. A combination of texture features and gray-level co-occurrence matrix features were extracted and used for training and testing purposes. The system was trained with 150 images, while a total 100 mammogram images were used for testing. A classification accuracy of more than 95% was obtained with our proposed method.

• Journal of applied mathematics & informatics
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• v.5 no.3
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• pp.827-837
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• 1998

We consider the M/G/1 queue with instantaneous feed-back. The probabilities of feedback are determined by the state of the underlaying Markov chain. by using the supplementary variable method we derive the generating function of the number of customers in the system. In the analysis it is required to calculate the matrix equations. To solve the matrix equations we use the notion of Ex-tended Laplace Transform.

• Journal of the Korean Institute of Telematics and Electronics
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• v.6 no.1
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• pp.19-22
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• 1969

Detailed analysis has been developed concerning the transfer function and stability condition of the logarithmic amplifier using a common emitter transistor as a feed-back element. The analysis shows that input current vs output voltage transfer characteristics is accurately ogarithmic through entire operating current, and the time constant depends on input capcitance and collector-emitter equivalent resistance. Also the minimum value of imput capacitance required to stabilize the system is derived.

• PNF and Movement
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• v.5 no.1
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• pp.19-28
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• 2007

Proprioception means the ability to perceive the sensation of position and movement of body. As it is transmitted to central nervous system and used in feed-back or feed-forward motor control, proprioception allows us to keep our normal movement and normal balance activity. However, the conditions such as injury, disease, aging and fatigue can damage the proprioceptiive sensation of position, movement and lead to a functional impairment and additional damages in musculoskeletal system, because they alter the amount of proprioceptive ability that transfer into the central nervous system. The purpose of this study was to identify the definition and the function of proprioception, to look into variations in injury, disease, aging and fatigue that can be easily met in clinical application and eventually to provide valuable aid for assessment and treatment.

• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.11-20
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• 1992

We discuss the feed back control of the on-line QC in the Taguchi method. Taguchi(1982) used the assumptions that the quality characteristics follow an uniform distribution and the Brownian motion to draw the loss function and proposed ${\Delta}/3$ or ${\Delta}$ for the initial control limit. Adams and Woodall(1989) also proposed a different procedure but using the same loss function. We propose, in this paper the new loss function under the assumption of mainly Brownian motion and compare the results with the results of the above.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.620-621
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• 2015

In this study, the multi-criteria decision-making model based on Quality Function Deployment Method is proposed. Multicriteria decision-making is an attempt to link QFD method with the TOPSIS. By this effort, a model that makes client's decision-making more rational and objective in design phase is suggested. The multi-criteria decisionmaking model confirming to the Owner's requirements will improve the productivity of the construction industry and the satisfaction of the customer. Further study extending the range of the requirements, not only the Owner's requirement will be necessary to cover the various factors as much as possible. And then, finally as a flexible platform to achieve a sustainable quality management, web-based multi-criteria decision-making model can be utilized by the relevant stakeholders simultaneously with the feed-back and sharing the necessary informations.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.3
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• pp.321-328
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• 1998

When we control the level of the steam generator in the nuclear power plants, a swell and shrink arises from many disturbances such as feed water rate, feed water temperature, main steam flow rate, and coolant temperature. If we use the conventional type of PI controller in this system, we will not have stability during controlling at lower power, the removal function of disturbances, and a load follow-up control effectively. In this paper, we study the application of a 2-Degree of Freedom(2-DOF) PID controller to the level control of the steam. generator of nuclear power plants through the simulation and the experimental steam generator. We use the parameters $\alpha$, $\beta$, $\gamma$ of the 2-DOF PID controller for the removal of disturbances and the parameters Kp,Ti,Td of the conventional type of PID controller for controlling setpoint. The back-propagation learning algorithm of neural network is used for tuning the 2-DOF PID controller. We can find satisfactory results of the removal of the disturbances and the tracking function in the change of setpoint through the simulation and experimental steam generator.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.8
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• pp.1765-1772
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• 2015

In the underwater acoustic communication channels, multipath reflection become the cause of obstacle. Generally, equalizer has been applied to overcome these problems. In this paper, the method was proposed to optimize tap-length of decision feedback equalizer using genetic algorithm. After inputting feed-forward filter length and feed-back filter length as genetic information of the genetic algorithm, it optimize tap-length using BER(bit error rate) calculation in accordance with object function. The object function consist of decision feedback equalizer and BER calculation. For the purpose of BER calculation in the object function, the method was proposed to optimize the tap-length of decision feedback equalizer with genetic algorithm using preamble signals. As a result of experiments, the optimized BER is 0.0355 for signals which were received through a 25m receiver and which were applied to calculate BER merely using preamble signals in object function. When all data were used to calculate BER in object function, the optimized BER is 0.0215.