• Journal of Institute of Convergence Technology
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• v.3 no.2
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• pp.11-15
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• 2013

These days, the quality of goods is required to improve in the process of manufacturing the semiconductor through the short working hours and clean transportation. The non-contact transport device using magnetic levitation can be a solution in the manufacturing process. The non-contact transport device, using electromagnetic actuation, is the system that can actually transport them by only using attraction force from the electromagnetic source without authentic contact. Moreover, the system using electromagnetic force has a substantial number of benefits ranging from unrestricted design to unlimited expansion. Especially, the price is competitive. The non-contact transport device, using electromagnetic force, has another merits in controlling by giving the same amount of attraction force to ferromagnetic body. By controlling the currents given to coil, the operator is able to decide the direction of the transportation. In order to design the optimal system, we implemented five different things such as the presence of the links below the electromagnetic, the electromagnet changes due to coupling method, the change according to the thickness of the links below electromagnet, due to changes in between electromagnetic distance direction, and the size of the current. Through simulations and the optimum design, it seems to control easily and figure out the exact size of power. It might definitely be the non-contact transport that can sharply reduce tiny scratches and particles in the process of manufacturing the semiconductor.

• 제어로봇시스템학회:학술대회논문집
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• 1998.10a
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• pp.391-394
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• 1998

The man-machine interface Is an important factor in the computer system, and it is thought that line-of-sight (LOS) detection technology will allow significant advances in this field. Techniques for detecting LOS for use in human interfaces have been studied［1]［2］. In earlier studies, however, LOS was detected with a head piece, goggles, or through fixing the position of the head. The limitations imposed by these fixed conditions render them unsuitable far use in interfaces, as they have adverse mental or physical effects on humans. Therefore. they have not been sufficiently developed for practical application. Research on non-contact LOS detection is expected to result in a usable LOS man-machine interface［3］［4］, and the current study is intended to be a step in that direction. The authors used color contact lenses for LOS detection, and applied this new method to a computer interface. The use of color contact lenses simplifies image processing. The algorithm used in this study is sufficiently accurate for practical applications. This technique can be used in input devices, in virtual reality applications, and in human engineering research.

• Tribology and Lubricants
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• v.20 no.5
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• pp.278-283
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• 2004

O-ring seal is widely used for sealing pressure vessels and oil containers in various applications of mechanical equipments. The doughnut shape of the O-ring is very important components in most of the system assembly of mechanical apparatus. This paper presents the sealing force of a pressurized perfluoroelastomer O-ring, which is very important contact seal in sealing the semiconductor equipment. The sealing pressure is measured by experimental method and analyzed numerically by using the non-linear MARC finite element program. The seal tester is made to measure the contact force and displacement of the O-ring with an automatic control system of the working temperature. The results show the reasonable agreements between the computed FEM results and measured ones when the operating temperature is moderate temperature. But the compared values between the computed and tested results show a difference because of the increased temperature, which is related to the non-linear parameter of the O-ring material.

• Transactions of Materials Processing
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• v.29 no.3
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• pp.144-150
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• 2020

In this paper, we propose the generation of a double enveloping worm thread profile with a non-developable ruled surface. Thread surface machining cuts all the way from the tip to the tooth root at one time, like full-face contact machining, rather than cutting several times like point machining. This cutting can reduce the cutting duration and achieve the smooth surface that does not require a grinding process for the threaded surface. The mathematical model of the cutting process was developed from theoretical equations, and the tooth surface was generated using two parameters and modeled in the CATIA using the generated Excel data. Additionally, the machining process of the worm was simulated in a numerical control simulation system. To verify the validity of the proposed method, the deviation between the modeling and the workpiece was measured using a 3D measuring machine.

• Journal of Practical Engineering Education
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• v.13 no.2
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• pp.305-320
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• 2021

Due to COVID-19, the education and training environment in vocational competency development has changed significantly. In vocational education and training, where the proportion of face-to-face training is more extensive than in other areas of education, some training courses had no choice but to be converted to online. This study presents a distance training system plan for non-contact vocational training by analyzing the learner's non-contact learning experiences. Non-face-to-face education experiences were investigated for learners of private vocational training institutions, universities, and public higher vocational training institutions. The main contents of the survey were to analyze the non-face-to-face learning experiences of these learners for the educational environment and educational purposes. Based on the results of the learners' non-face-to-face learning experiences, a draft of a remote training system construction plan for non-face-to-face education was composed, and a Delphi study was conducted on the draft non-face-to-face remote training system. A method for establishing a distance training system including non-face-to-face teaching and learning strategies, learning and operation support was proposed with these results.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.131-139
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• 2005

It is very difficult to analyze the dynamic characteristic because tilting vehicle is a very complex system which are connected various mass element with tilting system. To realize and analyze actual phenomenon has restriction that usual commercial software calculates creep force under creep theory about wheel -rail contact mechanism as basic analyzing, and approach about contact point are based on two dimensional non-linear contact theory and simplified Hertzian contact which considers just displacement change on the YZ plain. Therefore, to solve these problems there should be a new approach difference with existing one. In this research, a new algorithm for finding wheel-rail contact position, calculation method of contact force and applied force will be presented.

• Nuclear Engineering and Technology
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• v.43 no.5
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• pp.447-458
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• 2011

This paper proposes an approximated contact force model to identify the nonlinear behavior of a fuel rod with gap supports; also, the numerical prediction of interfacial forces in the mechanical contact of fuel rods with gap supports is studied. The Newmark integration method requires the current status of the contact force, but the contact force is not given a priori. Taylor's expansion can be used to predict the unknown contact force; therefore, it should be guaranteed that the first derivative of the contact force is continuous. This work proposes a continuous and differentiable contact force model with the ability to estimate the current state of the contact force. An approximated convex and differentiable potential function for the contact force is described, and a variational formulation is also provided. A numerical example that considers the particularly stiff supports has been studied, and a fuel rod with hardening supports was also examined for a realistic simulation. An approximated proper solution can be obtained using the results, and abrupt changes from the contacting state to non-contacting state, or vice versa, can be relieved. It can also be seen that not only the external force but also the developed contact force affects the response.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.6
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• pp.701-709
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• 2019

Recently, heart rate signal, which is one of biological signals, have been used in various fields related to healthcare. Conventionally, most of the proposed heart rate signal detection methods are contact type methods, but there is a problem of discomfort that the subject have to contact with the device. In order to solve the problem, detection study by non-contact method has been progressed recently. The detected heart rate signal can be used for finger vein liveness detection and various application using heart rate. In this paper, we propose a method to obtain heart rate signal by using finger vein imaging system. The proposed method detected the signal from the changes of the brightness value in the time domain of the infrared finger vein images and converted it into the frequency domain using the image processing algorithm. After the conversion, we removed the noise not related to the heart rate signal through band-pass filtering. In order to evaluate the accuracy of the signal, we analyzed the correlation with the signal obtained simultaneously with the finger vein acquisition device and contact type PPG sensor approved by KFDA. As a result, it was possible to confirm that the heart rate signal detected in non-contact method through the finger vein image coincides with the waveform of actual heart rate signal.

• Journal of Korean Society for Quality Management
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• v.37 no.2
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• pp.1-11
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• 2009

Recently, many companies have been very interested in CRM(Customer Relationship Management). Most companies have been also considering the contact center as a key CRM channel, because it is a contact point between customers and companies. It turns out that the contact center handles over 70% of all customer-company interactions and the success or failure of a company can be determined by the customer satisfaction with contact center experiences. Despite of the strategic importance of the contact center, there has been few empirical study on the efficiency of contact center operations in the literature. One of the main purposes of this study is to evaluate the efficiency of contact centers so as to not only identify the current status of contact center operations, but also suggest ways to improve operational efficiency. For this purpose, we apply a non-parametric efficiency measurement method, DEA (Data Envelopment Analysis), to 57 domestic contact centers in order to compare their relative efficiency. It is expected that the measurement methods suggested in this study can be applied to various issues such as service KS certification, outsourcing service management, and the productivity analysis of service personnel.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1996.10a
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• pp.183-188
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• 1996

Films and coatings are used for an enormous and diverse set of applications including mechanical, electronic and optical devices, protection at high temperature, cutting tools enhancement and automotive use. Many of these applications require the various properties associated with inorganic and metallic / non-metallic materials; i.e., with ceramics. Therefore, a large number of coatings have been developed and used for a long time in the various fields, especially in mechanical one. As one of the mutual surface actions, the problems of contact stresses are complex. The relationship between load and stress are nonlinear. Besides, the material is often apt to deform plastically under low load. However, analytical solutions exist only for some simple problems. If a material has a complicated shape or inhomogeneous properties, numerical method must be used. In this paper, the analysis of the contact stress of the coating layer was solved, using the finite element method.