• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.1 s.12
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• pp.33-40
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• 2004

The objective of this study is to develop single dam operation models for flood control using Fuzzy control technique, which can improve flood controllability. We set control rules by water level and inflow, and developed three models Fuzzy I, II, III according to rule to decide outflow. Fuzzy I model consists of six rules considering only flood control and Fuzzy II model considers the effect of water use by increasing water level at the end of flood control period as well as flood control during the same period. Finally, Fuzzy m is an adaptive model designed to perform multipurpose dam operation for both flood control and water use simultaneously based on a control rules.

• Journal of the Korean Mathematical Society
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• v.33 no.4
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• pp.879-889
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• 1996

In order to describe the nearness between fuzzy sets various structures like the fuzzy neighorhood structure ([7])), the Artico-Moresco fuzzy proximity ([2]) and the Lowen fuzzy uniformity ([8]) have been introduced.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.9
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• pp.117-123
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• 1996

In this paper, we present a new learning method for the fuzzy ARTMAP which is effective for the noisy input patterns. Conventional fuzzy ARTMAP employs only fuzzy AND operation between input vector and weight vector in learning both top-down and bottom-up weight vectors. This fuzzy AND operation causes excessive update of the weight vector in the noisy input environment. As a result, the number of spurious categories are increased and the recognition ratio is reduced. To solve these problems, we propose a new method in updating the weight vectors: the top-down weight vectors of the fuzzy ART system are updated using weighted average of the input vector and the weight vector itself, and the bottom-up weight vectors are updated using fuzzy AND operation between the updated top-down weitht vector and bottom-up weight vector itself. The weighted average prevents the excessive update of the weight vectors and the fuzzy AND operation renders the learning fast and stble. Simulation results show that the proposed method reduces the generation of spurious categories and increases the recognition ratio in the noisy input environment.

• Journal of Biosystems Engineering
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• v.23 no.1
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• pp.75-82
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• 1998

Autonomous speedsprayer operation was conducted using a fuzzy controller combined with a DGPS. The signal of DGPS receiver and signals of four ultrasonic sensors were processed in real time. The speedsprayer was steered with two levers controlled by two hydraulic cylinders. The fuzzy controller has two inputs; direction of running obtained from the DGPS receiver and distance from trees measured by ultrasonic sensors. The operation times of the hydraulic cylinders were inferred as outputs of the fuzzy controller. Field test results showed that the speedsprayer could be autonomously operated by the developed fuzzy controller including turning operation in the end of the tree row. The ultrasonic sensors contributed a little to performance of the autonomous operation, but the speedsprayer could avoid trees or obstacles in emergent situations with them.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2004.04a
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• pp.363-366
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• 2004

We propose some properties of fuzzy multonomial analysis of variance by fuzzy vector operation with agreement index.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.7
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• pp.149-158
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• 1994

Recently the fuzzy control is widely used as a tool for constructing automatic control systems which can replace the manual operation of large-scale nonlinear plants. In most applications of the fuzzy control however it is hard to meet the requirement of the operation time. In some real-time control the fuzzy control scheme requires too much computing time for fuzzification inference and defuzzification. To reduce the computing time there may be two alternatives the development of a new operation algorithm and the design of high-speed fuzzy hardware. In this paper to solve the problem of reducing the fuzzy operation time we propose a new high-speed fuzzy hardware scheme which has merits of its generality and extensibility. Finally we verify the proposed fuzzy hardware.

• Journal of Electrical Engineering and information Science
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• v.3 no.2
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• pp.131-138
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• 1998

We derive a back-propagation learning algorithm of fuzzy neural networks using fuzzy operations, which preserves the shapes of fuzzy numbers, in order to utilize fuzzy if-then rules as well as numerical data in the learning of neural networks for classification problems and for fuzzy control problems. By introducing the shape preseving fuzzy operation into a neural network, the proposed network simplifies fuzzy arithmetic operations of fuzzy numbers with exact result in learning the network. And we illustrate our approach by computer simulations on numerical examples.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.489-491
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• 1993

Many optimization problem or multiple attribute, multiple alternative decision making problem may have fuzzy evaluation factors. In this case, fuzzy number operation technique is needed to evaluate and compare object functions which become fuzzy sets. Generally, fuzzy number operations can be defined by extension principle of fuzzy set theory, but it is tedious to do fuzzy number operations by using extension principle when the membership functions are defined by complex functions. Many fast methods which approximate the membership functions such as triangle, trapezoidal, or L-R type functions are proposed. In this paper, a fast fuzzy number operation method is proposed which do not simplify the membership functions of fuzzy numbers.

• Journal of the Korean Society of Hazard Mitigation
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• v.4 no.3 s.14
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• pp.61-72
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• 2004

In this research, multi reservoir operation methods for reservoirs in Han River are proposed based on the single dam operation models using fuzzy control techniques. The result of fuzzy controled single dam operation has shown that it can improve flood controllability at the downstream of dams. Among the many control rules of fuzzy operation, a rule that shows the most effective flood control rate at the downstream has been selected as Ike operation rule. The simulated results for 1990 and 1995 flood events are compared with historical ones. As the results, it is founded that suggested models can reduce the inundation of upstream and keep the water elevation lower at downstream, which make the proposed models as the effective methods in multi reservoir operation.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.128-130
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• 1995

This paper presents the optimal operation scheduling on cogeneration systems connected with auxiliary equipment by using the possibility fuzzy theory. The probability fuzzy theory is a method to obtain the possibility of the solution from the fuzzification of coefficients. Simulation is carried out to obtain the boundary of heat production in each time interval. Simulation results shows effectively the flexible operation boundary to establish operation scheduling.