• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.10a
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• pp.345-350
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• 2002

In this study, researchers classifying the artificial flaws in semiconductor packages are performed by pattern recognition technology. For this purposes, image pattern recognition package including the user made software was developed and total procedure including ultrasonic image acquisition, equalization filtration, binary process, edge detection and classifier design is treated by Backpropagation Neural Network. Specially, it is compared with various weights of Backpropagation Neural Network and it is compared with threshold level of edge detection in preprocessing method fur entrance into Multi-Layer Perceptron(Backpropagation Neural network). Also, the pattern recognition techniques is applied to the classification problem of defects in semiconductor packages as normal, crack, delamination. According to this results, it is possible to acquire the recognition rate of 100% for Backpropagation Neural Network.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.54-59
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• 2014

The rapid tactical operation and mobility are getting important to recently developed the guided weapon systems. And military wants multi-purposes equipment to carry the war more easily. So military wants to have the equipment that can apply without any distinction about environment. For this reason, the robust design is getting more important now to guarantee survivability of equipment. In this paper, we try to check about structural integrity of Fire Control Unit(FCU) which is one of the guided weapon system using dynamic FEM analysis.

• The Journal of Korea Robotics Society
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• v.2 no.2
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• pp.168-177
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• 2007

In a number of fields, robots are being used for two purposes: efficiency and safety. Most robots, however, have single-actuator mechanism for each joint, where the tasks are performed with high stiffness. High stiffness causes undesired problems to the environment and robots. This study proposes redundant actuator mechanism as an alternative idea to cope with these problems. In this paper, Double-Actuator Unit (DAU) is implemented at each joint for applications of multi-link manipulators. The DAU is composed of two motors: the positioning actuator and the stiffness modulator, which enables independent control of positioning and compliance. A three-link manipulator with DAUs enables adaptive control of RCC. By modulating the joint stiffness of the manipulator and controlling the position of RCC, we can significantly reduce contact force during assembly tasks and surgical procedures.

• Journal of the Korean Society for Heat Treatment
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• v.2 no.2
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• pp.1-10
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• 1989

In this study, the specimens of SCM 22 H steel were quenched in oil and water baths at various agitation conditions in order to investigate the effects of quenchants and agitation conditions on the quench-hardening. A multi-channel temperature measurement apparatus was employed to obtain the cooling curves at several predetermined positions of specimens. Microstructural observation and hardness test were also carried out. Computer simulation of heat treating process was carried out using the modified finite difference method. Prediction of thermal history and hardness distribution by 2-dimensional computer analysis was in good agreement with the experimental results. It was found that the quantitative design of heat treating process can be made by the computer aided heat-treating analysis.

• Architectural research
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• v.3 no.1
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• pp.1-7
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• 2001

This paper try to provide basic insight of the changing functions of urban parks for the future direction of the maintenance and management of the urban parks using the results of the case study done for the city of Osaka, Japan. To accomplish this purpose this study considers the behavior characteristics of the elderly within the parks in Osaka, Japan. Based on the findings of the study authors propose the chaining meaning of urban parks in the users perspective and summarize the results of the study. Study results show high values on the environmental factors of the park, such as the fresh air and the shadow of trees and low values on noise and stairways in it. The multidimensional quantitative III classifies the purposes of the elderly using the parks into 3 types: a multi-use type, a walking type and a sightseeing type.

• Computers and Concrete
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• v.16 no.5
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• pp.683-701
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• 2015

When approached using nonlinear finite element (FE) techniques, structural analyses generate, for real RC structures, large complex numerical problems. Damage is a major part of concrete behavior, and the discretization technique is critical to limiting the size of the problem. Based on previous work, the ${\mu}$ damage model has been designed to activate the various damage effects correlated with monotonic and cyclic loading, including unilateral effects. Assumptions are formulated to simplify constitutive relationships while still allowing for a correct description of the main nonlinear effects. After presenting classical 2D finite element applications on structural elements, an enhanced simplified FE description including a damage description and based on the use of multi-fiber beam elements is provided. Improvements to this description are introduced both to prevent dependency on mesh size as damage evolves and to take into account specific phenomena (permanent strains and damping, steel-concrete debonding). Applications on RC structures subjected to cyclic loads are discussed, and results lead to justifying the various concepts and assumptions explained.

• Journal of the Korea Safety Management & Science
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• v.5 no.2
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• pp.99-109
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• 2003

This study tries to grasp common problems which most companies utilizing CRM are facing and present solutions to such problems in utilizing CRM. For these purposes, we try to determine the most important and most urgent factors in CRM utilization by using AHP, one of the Multi-criteria decision-making methods proposed by Satty. AHP is widely used for determining relative magnitude per evaluation item, i. e. priority on problems and is expected to make more systematic and objective evaluations than conventional methods do. Even in the present situation where any general criterion on CRM dose not exist, utilization of CRM is expected to be actively continued, which will cause many problems. In this regard, evaluating CRM counts. This study also tries to present a model applicable to such CRM evaluations

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.06a
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• pp.173-184
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• 1994

A method of obtaining deformation severity of axisymmetric shape deep-drawn products was developed. Strain states of products produced by single or multi-stage drawing were predicted by using finite element analysis. This method used minimization of potential energy between the known shape of final product and the unknown in initial blank. And that was done numerically by nonlinear finite element method. Deformation theory of plasticity was used for practical purposes. From predicted strain states of drawn parts, deformation severity was found by using forming limit diagrams.

• ETRI Journal
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• v.40 no.5
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• pp.643-652
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• 2018

Dysarthria is a degenerative disorder of the central nervous system that affects the control of articulation and pitch; therefore, it affects the uniqueness of sound produced by the speaker. Hence, dysarthric speaker recognition is a challenging task. In this paper, a feature-extraction method based on deep belief networks is presented for the task of identifying a speaker suffering from dysarthria. The effectiveness of the proposed method is demonstrated and compared with well-known Mel-frequency cepstral coefficient features. For classification purposes, the use of a multi-layer perceptron neural network is proposed with two structures. Our evaluations using the universal access speech database produced promising results and outperformed other baseline methods. In addition, speaker identification under both text-dependent and text-independent conditions are explored. The highest accuracy achieved using the proposed system is 97.3%.

• Journal of electromagnetic engineering and science
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• v.10 no.4
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• pp.224-230
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• 2010

Wireless power transmission (WPT) is useful technology in near future. There are some kinds of the WPT technologies, WPT via radio waves, resonance coupling, and inductive. Especially the WPT via radio waves is used for multi-purposes from short range to long range application. However, unfortunately it is misunderstood that it is low efficiency and low power. In this paper, I show the theory of beam efficiency between transmitting antennas and receiving antennas and also show some high efficient applications of the WPT via radio waves. Especially, I pick up a wireless power charging system of an electric vehicle and show the experimental results. I show difference between the theory of beam efficiency and the experimental results of short range WPT. I indicate that reasons of poor beam efficiency in the experiment are (1) change of impedance caused by mutual coupling between transmitting antennas and receiving antennas, (2) oblique direction of microwave power to receiving antennas caused by short distance.