• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.8
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• pp.1503-1517
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• 1994

Intelligent Motion Planning System(IMPS) is presented for a robot to achieve an efficient path toward the given target point in two dimensional unknown environment is constructed with unrestricted obstacle shapes. IMPS consists of three components for making intelligent motion. These components are real-time motion planning algorithm based on a discontinous boundary method, fuzzy neural network decision system for heuristic knowledge representation, and world modeling with forgetting and reinforcing memory cells. First of all, in real-time motion planning algorithm, the behavior-based architectural method is used to generate subgoal. A behavior generates a subgoal independently by using the method of discontinuous boundary in sensed area. The discontinuous boundary method is a new proposed fast obstacle avoidance algorithm. The second component is fuzzy neural network decision system for accomplishing the subgoal. The heuristic rules are imbedded on the fuzzy neural network to make an intelligent decision. The last one is a forgetting, reinforcing memory technique for the construction of external world map. The activation values of all activated memory cells in grid space are decreased monotonically and after all they are burned out. Therefore, after sufficient journey, robot can have a stationary world map even if the dynaic obstacles exist. Using the IMPS, several simulations show the efficient achievement of target point in unknown enviroment with obstcles of various shapes.

• Journal of The Korean Association For Science Education
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• v.25 no.5
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• pp.610-623
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• 2005

This was a theoretical study of which the goal was to provide a foundation for developing and implementing earth science inquiry activities based on abduction as a scientific inquiry method. Through a review of relevant literature, the study examined the nature of earth science in terms of the goals of earth science inquiry and the characteristics of what is investigated in earth science. It also explored the forms and meanings of abduction, thinking strategies used in the abductive inference, and the abductive inquiry model. Abduction is the process of inferring certain rules (e.g., scientific facts, principles, laws) and providing explanatory statements or hypotheses in order to explain some phenomena. This method was found to be well-suited to the earth science inquiry which studies the causes and processes of natural phenomena in the earth and space environment. Abduction has the nature of ampliative, selective, evaluative, and creative inference, and several thinking strategies, including reconstruction of data, heuristic generalization, analogy, existential, conceptual combination, and elimination strategies, are employed for inferring rules and suggesting hypotheses. This study found the abductive inquiry model to be adaptable to earth science classrooms, and it is therefore suggested that earth science instructions should be based on the abductive method and that research work concerning the abductive inquiry in the classroom should follow.

• The Journal of the Korea Contents Association
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• v.15 no.7
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• pp.181-192
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• 2015

Nonverbal immediacy plays a key role in interpersonal communication, inducing closeness and another interaction. This case study investigates the nonverbal behaviors in Human-Robot Interaction(HRI) focusing on immediacy, and how they affect perception of a robot. The results show that nonverbal immediacy, such as nodding and leaning forward, affect perceived interactivity. Nonverbal immediacy can be interpreted their meaning clearly when verbal feedback or other communication channel reinforcing them. Also, touch is found to affect come up with similar ones to the robot, because it is associated with concrete and discrete context. People tend to apply social rules to the robot, but they are more open to the unfamiliar robot compared to strangers. The findings in this study provide future HRI studies with heuristic implications by showing a direction and clarifying principles for composition of verbal and nonverbal expression.

• Journal of the Korean Institute of Intelligent Systems
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• v.7 no.4
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• pp.48-57
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• 1997

This paper presents the automatic construction and parameter optimization technique for fuzzy logic controllers using genetic algorithm. In general. the design of fuzzy logic controllers has difficulties in the acq~lisition of expert's knowledge and relies to a great extent on empirical and heuristic knowledge which, in many cases, cannot be objectively justified. So, the performance of the controllers c:an be degraded in the case of plant parameter variations or unpredictable incident which a designer may have ignored, and the parameters of fuzzy logic controllers obtained by expert's control action may not be optirnal. Some of these problems can be resolved by the use of genetic algorithm. The proposed method can tune the parameters of fuzzy logic controllers including scaling factors and determine: the appropriate number of fuzzy rulcs systematically. Finally, we provides the second order dead time plant to evaluate the feasibility and generality of the proposed method. Comparison shows that the proposed method can produce fuzzy logic controllers with higher accuracy and a smaller number of fuzzy rules than manually tuned fuzzy logic controllers.

• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.354-365
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• 1993

A novel control method with automatic tuning of PID controller parameters has been developed for efficient regulation of dissolved oxygen concentration in fed-batch fermentations of Escherichia coli. Agitation speed and oxygen partial pressure in the inlet gas stream were chosen to be the manipulated variables. A heuristic reasoning allowed improved tuning decisions from the supervision of control performance indices and it coule obviate the needs for process assumptions or disturbance patterns. The control input consisted of feedback and feedforword parts. The feedback part was determined by PID control and the feedforward part is determined from the feed rate. The proportional gain was updated on-line by a set of heuristics rules based on the supervision of three performance indices. These indices were output error covariance, the average value of output error, and input covariance, which were calculated on-line using a moving window. The integral and derivative time constants were determined from the period of output response. The specific growth rate was maintained at a low level to avoid acetic acid accumulation and thus to achieve a high cell density. The specific growthe rate was estimated from the carbon dioxide evolution rate. In fed-batch fermentation, the simutaneous control of dissolved oxygen concentration (at 0.2; fraction of saturated value) and specific growth rate (at 0.25$hr^{-1}$) was satisfactory for the entire culture period in spite of the changes in the feed rate and the switching of control input.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.05a
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• pp.155-160
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• 2003

This paper presents a multiple face detector based on a robust pupil detection technique. The pupil detector uses active illumination that exploits the retro-reflectivity property of eyes to facilitate detection. The detection range of this method is appropriate for interactive desktop and kiosk applications. Once the location of the pupil candidates are computed, the candidates are filtered and grouped into pairs that correspond to faces using heuristic rules. To demonstrate the robustness of the face detection technique, a dual mode face tracker was developed, which is initialized with the most salient detected face. Recursive estimators are used to guarantee the stability of the process and combine the measurements from the multi-face detector and a feature correlation tracker. The estimated position of the face is used to control a pan-tilt servo mechanism in real-time, that moves the camera to keep the tracked face always centered in the image.

• Korean Journal of Cognitive Science
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• v.1 no.2
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• pp.317-346
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• 1989

A congnitive shape decomposition method that agrees with human intuition is proposed for the conceptual recognition from sillouettes of objects. Descriptions specifying the structure of shape in terms of meaningful parts and relations have cognitive power and anthropomorphism. In general, man-made objects have a lot of collinear lines and regularity. For the cognitive decomposition of man-made objects, many heuristic rules based on the cognitive experimentation are applied on the context of collinerarity and regularity. The cognitive shape decomposition for the natural shape is carried out by analyzing the possible configuraitions of vertices and line segments for one concave vertex. A cost function for the configuation is designed by weighted sum of five criteria such as, the length of split line segment, the number of split line segments at concave vertex, the proximity of concave vertex, and the correspondence of vertices. These criteria are vased on the property of human perception such as proximtiy, symmetry, and simplicity. The most promising vertex os selected among three set of visible vertices by evaluating the cost function. A number of experiments conducted on the different types of shapes shows that the results correspond with human intuition.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.550-564
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• 2020

Distillation columns are one of the main equipment used for the separation of chemical components in petrochemical process design. However, in spite of the efficient operation in wide range, and the advantage of data collection for equipment verification, the distillation columns are inherently known for high energy consumption and capital cost. Hence, the trade-off analysis needs to be done between investment cost and operation cost to develop the most economical distillation columns. This study was conducted using Aspen Plus, a popular process simulation program, in the pursuit of broad application by as many process engineers as possible. In this paper, design variables for optimization of distillation columns were defined to improve emphatically the design quality with reducing erratic practice of many engineers. In addition, by eliminating unnecessary reviewing step and establishing systematic and efficient procedures, the amount of time for design and human resources were minimized. Aspen Process Economic Analyzers (APEA) program was introduced in order to calculate the investment cost reliably, and the efficient systematic procedure for utilization of APEA was established.

• The Journal of the Acoustical Society of Korea
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• v.14 no.1
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• pp.31-39
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• 1995

In this paper, we have constructed phoneme discriminant filters [PDF] according to the linear discriminant function. These discriminant filters do not follow the heuristic rules by the experts but the mathematical methods in iterative learning. Proposed system. is based on the piecewise linear classifier and error correction learning method. The segmentation of speech and the classification of phoneme are carried out simutaneously by the PDF. Because each of them operates independently, some speech intervals may have multiple outputs. Therefore, we introduce the unified coefficients by the output unification process. But sometimes the output has a region which shows no response, or insensitive. So we propose time windows and median filters to remove such problems. We have trained this system with the 549 monosyllables uttered 3 times by 3 male speakers. After we detect the endpoint of speech signal using threshold value and zero crossing rate, the vowels and consonants are separated by the PDF, and then selected phoneme passes through the following PDF. Finally this system unifies the outputs for competitive region or insensitive area using time window and median filter.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1346-1353
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• 1996

In this paper, we propose a modeling method for the flip-flops and test generation algorithms to detect the faults in the sequential circuits using VHDL in the high-level design environment. RS, JK, D and T flip-flops are modeled using data flow types. The sequence of micro-operation which is the basic structure of a chip-level leads to a control point where varnishing occurs to one of two micro- operation sequence. In order to model the fault of one micro-operation(FMOP) that perturb another micro-operation effectively, the concept of goal trees and some heuristic rules are used. Given a faulty FMOP or fault of control point (FCON), a test pattern is generated by fault sensitization, path sensitization and determination of the imput combinations that will justify the path sensitization. The fault models are restricted to the data flow model in the ARCHITECTURE statement of VHDL. The proposed algorithm is implemented in the C language and its efficiency is confirmed by some examples.