• Structural Engineering and Mechanics
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• v.32 no.4
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• pp.489-500
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• 2009

The aim of this paper is to compare wavelet, kurtosis and pseudofractal based techniques for structural health monitoring in the presence of measurement noise. A detailed comparison and assessment of these techniques have been carried out in this paper through numerical experiments for the calibration of damage extent of a simply supported beam with an open crack serving as an illustrative example. The numerical experiments are deemed critical due to limited amount of experimental data available in the field of singularity based detection of damage. A continuous detectibility map has been proposed for comparing various techniques qualitatively. Efficiency surfaces have been constructed for wavelet, kurtosis and pseudofractal based calibration of damage extent as a function of damage location and measurement noise level. Levels of noise have been identified for each technique where a sudden drop of calibration efficiency is observed marking the onset of damage masking regime by measurement noise.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.99.2-99
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• 2002

Contents 1 In this paper a machine vision system for recognizing and classifying the patterns and marks engraved by die molding or laser marking on glass panel of computer monitor is suggested and evaluated experimentally. The vision system is equipped with a neural network based pattern classifier and searching process based on normalized grayscale correlation and adaptive binarization, which is applicable to the cases in which the segmentation of the pattern area from background using the ordinary blob coloring technique is quite difficult. Inspection process is accomplished via the way of NGC hypothesis and ANN verification. The proposed pattern recognition system is composed of three...

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.8
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• pp.1854-1868
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• 1995

An effective nesting algorithm has been proposed to allocate the arbitrary shapes on one or several raw sheets by applying the well-known simulated annealing algorithm as the optimization technique. In this approach, both the shapes to be allocated and the raw sheets are represented as the grid-based models. This algorithm can accommodate every possible situations encountered in cutting apparel parts from the raw leather sheets. In other words, the usage of the internal hole of a shape for other small shapes, handling of the irregular boundaries and the interior defects of the raw sheets, and the simultaneous allocation on more than one raw sheets have been tackled on successfully in this study. Several computational experiments are presented to verify the robustness of the proposed algorithm.

• Journal of Ocean Engineering and Technology
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• v.11 no.4
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• pp.239-248
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• 1997

The nesting of parts cut on raw steel plate has been a subject of interest to the shipbuilding industry for many years. "Nesting" is defined operation of layout of the parts on the raw material with minimizing the waste rate. Therefore, it is very important to optimize the cutting area. Since the existing nesting programs are prepared for expensive workstations and the expert, it is needed to develop nesting program for personal computer to improve the technology of small/middle sized shipyards and their productivity. This study involves development and application of appropriate optimization technique to solve the problem of plate nesting. And the appropriate D/B for storing nesting data developed, the function of D/B is introduced in this paper.his paper.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10a
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• pp.400-405
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• 1990

This paper deals with the design technique of the controller for the discrete system control using Extended Safe Petri Net which is deduced from Petri Net as its subclass with a specific constraint and which is introduced to develop the design and analysis for the discrete systems. First, we propose a construction matrix suitable for the discrete systems that represent the marking flows which are the dynamic behavior of the discrete systems. Next, we develop a method that can design the controller for the discrete system control by analyzing the proposed construction matrix into the incidence matrix of Extended Safe Petri Net. Finally, the validity of the proposed method is shown by using the incidence matrix and matrix equation of Extended Safe Petri Net model.

• Journal of the Korean Institute of Landscape Architecture
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• v.21 no.1
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• pp.83-94
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• 1993

After coming this century, as the propagative method of plants on a scientific foundation has been accompanied systematically, it has played an important part in the improvement of cultivar. But an existing propagative technique is not a few defects in our tasks and industrial structure which changes every hour and envirnment which undergoes a sudden change. To use developed biological knowledge recently, and existing propagative method which is main axis in sexual reproductive crossing, is increased much in the inside of internal organs by asexual reproductive means which is on a different level, and by, introducing a new character, it improves an inherited character etc. We have observed methods which supplement or replace a defect. These methods are not yet ripe for putting to practical use in the present research phase but convinced that they will offer an epoch-marking turning point.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.119-124
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• 1994

Morden industrial society pursues unmanned system and automation of manufacturing rocess. Abreast with this tendensy, prodution of goods which requires advaned accuracy is increasing as well. According to this, the work sensing time of dressing by monitoring and diagnosis the condition of grinding, which is the representative way in accurate manufacturing, is a important work to prevent serios damages which affect grinding process or products by wearing wheel. Computer vision system is composed, so that grind wheel wurface was acquired by CCD camera and the change of cutting is composed. Then we used autometic threshoding technique from histogram as a way of deviding cutting edge which is used in manufacturing from the other parts. As a result, we are trying to approach unmanned system and sutomation by deciding more accurate time of dressing and by visualizing behavior of grinding wheel by marking use of computer vision.

• Journal of National Security and Military Science
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• s.2
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• pp.285-314
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• 2004

The forms of current war are diversified over the pan-national industry. Among these, one kind of threats which has permeated the cyber space based on the advanced information technology causes a new type of war. C4ISR, the military IT revolution, as a integrated technology innovation of Command, Control, Communications, Computer, Intelligence, Surveillance and Reconnaissance suggests that the aspect of the future war hereafter is changing much. In this paper, we design the virtual decoy system and intrusion trace marking mechanism which can capture various attempts and evidence of intrusion by hackers in cyber space, trace the penetration path and protect a system. By the suggested technique, we can identify and traceback the traces of intrusion in cyber space, or take a legal action with the seized evidence.

• Journal of Korean Society for Quality Management
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• v.33 no.2
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• pp.1-12
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• 2005

An extensive literature review has been made in this paper to build the evaluation hierarchy structure for the certification of electronic commerce services. In building the evaluation hierarchy structure, major candidate evaluation factors are selected by bench marking the various certification practices, including the Malcolm Baldrige award, ISO9000, and BSC(balanced scorecard) techniques. This paper deployed principal component analysis and factor analysis techniques to develop a statistically solid and systematic evaluation model. The final evaluation model, as presented in this paper as a model for the certification of electronic commerce services, produces a numeric score on the 100% scale, which can be served as a metric for the certification decision. The AHP technique was used in converting the various qualitative and quantitative evaluation values into a single measure for the certification decision.

• Transactions of Materials Processing
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• v.3 no.3
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• pp.291-301
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• 1994

In the simultaneous forward-backward extrusion the effects of some process variables including area reduction, stroke advance, materials(Al 2024 and commercial pure copper) on the extrusion load, plastic flow and height ratio of upper to lower extruded parts are experimentally investigated and analyzed. Grid-marking technique is employed to visualize the plastic flow. The influence of using split and original specimen on the extrusion load and height ratio is evaluated by experiments. Experimental results show that the plastic flow if oriented to the part of lower area reduction in the begining but it is usually variated during the overall process. The configurations of plastic deformation and plastic flow are dependent on the working materials and the lubricational conditions.