• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.759-763
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• 1996

This paper presents a new approach to the design of neural control system using digital signal processors in order to improve the precision and robustness. Robotic manipulators have become increasingly important in the field of flexible automation. High speed and high-precision trajectory tracking are indispensable capabilities for their versatile application. The need to meet demanding control requirement in increasingly complex dynamical control systems under significant uncertainties, leads toward design of intelligent manipulation robots. The TMS320C31 is used in implementing real time neural control to provide an enhanced motion control for robotic manipulators. In this control scheme, the networks introduced are neural nets with dynamic neurons, whose dynamics are distributed over all the network nodes. The nets are trained by the distributed dynamic back propagation algorithm. The proposed neural network control scheme is simple in structure, fast in computation, and suitable for implementation of real-time control. Performance of the neural controller is illustrated by simulation and experimental results for a SCARA robot.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10C
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• pp.956-963
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• 2006

This research studies multi participant consistency and dynamic data shared through 3D scenes in virtual network environments. In a distributed virtual environment of client-server structure, consistency is maintained by the static information exchange; as jerks occur by packet delay when updating messages of dynamic data exchanges are broadcasted frequence, the network bottleneck is reduced by predicting the movement path by using the Dead-reckoning algorithm. In Dynamic data path prediction, the tests the location prediction error between Dead-reckoning convergence interval and error of prediction and actual condition one time above threshold it interpolates a previously location. The shared dynamic data of the 3D virtual environment is implementation using the VRML EAI.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3496-3514
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• 2015

One of the challenging tasks in Mobile Ad hoc Network is to discover precise optimal routing solution due to the infrastructure-less dynamic behavior of wireless mobile nodes. Ant Colony Optimization, a swarm Intelligence technique, inspired by the foraging behaviour of ants in colonies was used in the past research works to compute the optimal path. In this paper, we propose a Recurrent Ant Colony Optimization (RECACO) that executes the actual Ant Colony Optimization iteratively based on recurrent value in order to obtain an optimal path convergence. Each iteration involves three steps: Pheromone tracking, Pheromone renewal and Node selection based on the residual energy in the mobile nodes. The novelty of our approach is the inclusion of new pheromone updating strategy in both online step-by-step pheromone renewal mode and online delayed pheromone renewal mode with the use of newly proposed metric named ELD (Energy Load Delay) based on energy, Load balancing and end-to-end delay metrics to measure the performance. RECACO is implemented using network simulator NS2.34. The implementation results show that the proposed algorithm outperforms the existing algorithms like AODV, ACO, LBE-ARAMA in terms of Energy, Delay, Packet Delivery Ratio and Network life time.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.6
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• pp.1478-1485
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• 1993

A shape optimization problem is formulated to determine the optimal position of heating lines in a compression molding die. The objective of the problem is that the cavity surface would be maintained by a prescribed uniform temperature. A boundary integral equation for the sensitivity of the temperature in terms of hole position is derived using the method of shape design sensitivity analysis. The boundary element method is employed to analyze the temperature and sensitivity field of the die. The sensitivity calculation algorithm is incorporated in an optimization routine. To demonstrate a numerical implementation, an example problem arising in thermal design of a compression molding die is dealt with, showing that the number of heating lines chosen for the die strongly affects the ultimate uniformity of the cavity surface temperature.

• Asia pacific journal of information systems
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• v.11 no.2
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• pp.121-139
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• 2001

VOQL* query language, recently proposed, is a visual language for object-oriented databases. It is based on Ven Diagram and graph, so that the underlying schema structure can be naturally implied in query expressions. In VOQL*, structural relationship among the objects used in a query expression is represented graphically and thus it has formal semantics that can be inductively defined, as well as it can be used with ease. In this paper, we proposed revised VOQL* and introduced its query processor, InQs(Intelligent Querying System). While retaining the merit of VOQL* that it allows the structural relationship among the objects to be represented visually, the revised VOQL* has another merit that users can formulate a query interactively using various forms supplied by InQs. As a query processor that translates queries in revised VOQL into those in ODMG OQL, InQs provides an environment in which users express queries in revised VOQL* and then the system automatically translates them into those in ODMG OQL. Translation algorithm of InQs is much simpler and intuitive than other algorithms used in QUIVER and other systems, since it reflects the formal semantics of VOQL*, which is defined inductively.

• Journal of Korea Spatial Information System Society
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• v.12 no.1
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• pp.1-9
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• 2010

Recently, wireless sensor networks(WSNs) technology has been considered as one of the most critical issues in the ubiquitous computing age. The sensor nodes have limited battery power, so they should consume low energy through their operation for the long-lasting lifetime. Therefore, it is essential to use energy efficient routing protocol. For this, we propose a location-based energy-efficient routing protocol which constructs the energy efficient route by considering the quantity of Energy consumed. In addition, we propose a route reconstruction algorithm to handle the disconnection of message transmission. Finally, we show from performance analysis using TOSSIM that our protocol outperforms the existing location based routing protocols in terms of energy efficiency.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.607-614
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• 1996

A computer vision based automatic intelligent sorting system for dried oak mushrooms has been developed. The developed system was composed of automatic devices for mushroom feeding and handling, two sets of computer vision system for grading , and computer with digital I/O board for PLC interface, and pneumatic actuators for the system control. Considering the efficiency of grading process and the real time on-line system implementation, grading was done sequentially at two consecutive independent stages using the captured image of either side. At the first stage, four grades of high quality categories were determined from the cap surface images and at the second stage 8 grades of medium and low quality categories were determined from the gill side images. The previously developed neuro-net based mushroom grading algorithm which allowed real time on-line processing was implemented and tested. Developed system revealed successful performance of sorting capability of approximate y 5, 000 mushrooms/hr per each line i.e. average 0.75 sec/mushroom with the grading accuracy of more than 88%.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1235-1242
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• 2006

Viscoelastic damping materials are widely used to reduce noise and vibration because of its low cost and easy implementation, for examples, on the body structure of passenger cars, air planes, electric appliances and ships. To design the damped structures, the material property such as elastic modulus and loss factor is essential information. The four-parameter fractional derivative model well describes the nonlinear dynamic characteristics of the viscoelastic damping materials with respect to both frequency and temperature with fewer parameters than conventional spring-dashpot models. However the identification procedure of the four-parameter is very time-consuming one. An efficient identification procedure of the four-parameters is proposed by using an FE model and a gradient-based numerical search algorithm. The identification procedure goes two sequential steps to make measured FRFs coincident with simulated FRFs: the first one is a peak alignment step and the second one is an amplitude adjustment. A numerical example shows that the proposed method is efficient and robust in identifying the viscoelastic material parameters of fractional derivative model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.415-420
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• 2012

This paper proposes a novel type of tactile device utilizing magnetorheological (MR) fluid which can be applicable for haptic master of minimally invasive surgery (MIS) robotic system. The salient feature of the controllability of rheological properties by the intensity of the magnetic field (or current) makes this potential candidate of the tactile device. As a first step, an appropriate size of the tactile device is designed and manufactured via magnetic analysis. Secondly, in order to determine proper input magnetic field the repulsive forces of the real body parts such as hand and neck are measured. Subsequently, the repulsive forces of the tactile device are measured by dividing 5 areas. The final step of this work is to obtain desired force in real implementation. Thus, in order to demonstrate this goal a neuro-fuzzy logic is applied to get the desired repulsive force and the error between the desired and actual force is evaluated.

• Journal of Korea Spatial Information System Society
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• v.8 no.1 s.16
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• pp.27-35
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• 2006

As the increasing interest about geographical information, such researches and applied fields become wide. OGC(Open GIS Consortium) developed GML(Geography Markup Language) which is adopted XML(extensible Markup Language) in GIS field. In various applied field, GML is used and studied continuously. This paper try to find out the meaningful rules using Apriori algorithm from GML documents, one of the data mining techniques which is studied based on existing XML documents There are two ways to find out the rules. One is the way that find out the related rules as extracting the content in GML documents, the other find out the related rules based on used tags and attributes. This paper describes searching the rules through two ways and shows the system adopted two ways.