• Journal of the Korean Vacuum Society
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• v.1 no.1
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• pp.32-36
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• 1992

An ECR plasma apparatus is designed and constructed. The gradient of magnetic field in microwave cavity was adjusted to provide an ECR plasma stream by electro magnetic lenz system. Employing a yoke arround the electro magnets, the magnetic field intensity was increased by 50% with the same electric current. Characteristics of the ECR plasma discharged in the apparatus were investigated by Langmuir probe method. The variations of electron temperature and electron density along chamber axis were analysed.

• Structural Engineering and Mechanics
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• v.23 no.5
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• pp.525-542
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• 2006

On the basis of equilibrium equations for static electric and magnetic fields, two unknown functions related to electric and magnetic fields were firstly introduced to rewrite the governing equations, boundary conditions and initial conditions for mechanical field. Then by introducing a dependent variable and a special function satisfying the inhomogeneous mechanical boundary conditions, the governing equation for a new variable with homogeneous mechanical boundary conditions is obtained. By using the separation of variables technique as well as the electric and magnetic boundary conditions, the dynamic problem of a functionally graded magneto-electro-elastic hollow sphere under spherically symmetric deformation is transformed to two Volterra integral equations of the second kind about two unknown functions of time. Cubic Hermite polynomials are adopted to approximate the two undetermined functions at each time subinterval and the recursive formula for solving the integral equations is derived. Transient responses of displacements, stresses, electric and magnetic potentials are completely determined at the end. Numerical results are presented and discussed.

• Advances in materials Research
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• v.11 no.4
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• pp.331-349
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• 2022

In the present work, we proposed an analytical study on buckling behavior of a sandwich plate with polymeric core integrated with piezo-electro-magnetic layers such as BaTiO3 and CoFe2O4 reinforced by graphene platelets (GPLs). The Halpin-Tsai micromechanics model is used to describe the properties of the polymeric core. The governing equations of equilibrium are obtained from first-order shear deformation theory (FSDT) and the Navier's method is employed to solve the equations. The results show the effect of different parameters such as thickness, length, weight fraction of GPLs, and also effect of electric and magnetic field on critical buckling load. The result of this study can be obtained in the aerospace industry and also in the design of sensors and actuators.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.10a
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• pp.477-478
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• 2010

• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.188-188
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.652-655
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• 2003

This paper is about the recent development of the magnetic impact actuator for endoscope. The developed magnetic impact actuator has many problems to arrange in the system body. Because the magnetic impact actuator need a permanent magnet as an impacter, so the magnetic interference among magnets can not be eliminated. This interference causes the system size bigger. We need a new actuator design to solve these problems. One of the good solutions is to use the closed electro-magnetic circuit. This kind of circuit enhances the actuators to be independent. It is written about the design of the electro-magnetic circuit and simulation using Maxwell(version 9.0)

• Journal of Coastal Disaster Prevention
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• v.5 no.4
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• pp.173-182
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• 2018

As the research about increasing the efficiency of dredging soil transport, the technology, which reduce the friction between pipe wall and fluid in the pipe and disturbed generating pipe blockage, has been developed. So for the purpose of applying this technology to real construction site, main test has been tried at the real scale test in field. As a test result, this paper will show 30% flow efficiency increasing by permitted electro magnetic force to the pipe. And test result was evaluated as a ultra sonic velocity profiler. To propose the design technique and the execution manual of the high efficiency dredging material transport technic, this research have confirmed flow status changing depending on a soil material kind under electro-magnetic field and analyze the effect of electro-magnetic field which affects to each dredged soil material transportation. For achieving this research, EMF(Electro-Magnetic Field) generator is installed on the dredger(20,000HP) and through monitored flow status, dredging soil flow rate and sampled material specification is confirmed. Also dredger operating condition is measured and dredger power for soil transportation, hydraulic gradient and flow rate are compared, as transportation efficiency is calculated by this parameter, it is possible to check transportation efficiency improvement depending on each dredged soil material under electro-magnetic field. To verify the technique of dredged soil transfer using electromagnetic field, which is the core technique of the high efficiency dredged soil transfer, and the technique of expert system for pipeline transfer and the flow state. This could lead to a verification of transfer efficiency according to the characteristics of the dredged soil (sand, clay, silt) and the transfer distance (5km, 10km, 15km), which is planned to be used for a technology development of pump power reduction and long-distance transfer applying the high efficiency dredged soil transfer technology.

• Journal of Haehwa Medicine
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• v.25 no.1
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• pp.53-62
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• 2016

Objectives : The purpose of this study was to report a case of a patient efficacy of electromagnetic acupuncture using Whata 153 in facial nerve palsy in Herpes zoster oticus. Methods : We treated the patient with magnetic acupuncture combined with electro-acupuncture. Acupuncture points were at the face (BL2, GB14, TE23, ST4, ST6, ST3). All the acupuncture points were stimulated with magnetic field and 4 of them were combined with electro-acupuncture. Results & Conclusions : The improvement of facial movement and symptom was evaluated by Yanagihara grading system(Y-system), House-Brackmann scale(HB scale) and Sunnybrook facial grading system(SFGS). After treatment, all of the scales(Y-system, HB scale and SFGS) and symptom of the patient were improved. From the above results, we suggest that magnetic acupuncture and electro-acupuncture might be effective on facial nerve palsy in Herpes zoster oticus.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.28 no.12
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• pp.509-514
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• 2016

From the point of view to prevent airborne infection-related diseases such as H1N1, SARS, and MERS, an actual application of air cleaning and purification systems including technologies like UVGI has become increasingly important. Recently, an air purification system using REME (Reflective Electro Magnetic Energy) developed in the U.S. is applied for indoor air purification and sterilization technology to counteract the outbreak of new airborne infections. In this study, an air sterilization performance experiment using REME was carried out. The results verified that air sterilization performance in the case of installing a REME system in a medical center was 31%, namely the number of floating bacteria decreased by 31% after only a five-day operation. In addition, the number of culture collections in the REME operating air conditioning systems using nonpathogenic Geobacillus stearothemophilus as a biological indicator decreased maximally to 67%. A field application of REME technology will be useful to prevent airborne infection-related diseases, especially in response to public health crises due to the advent of emerging diseases.

• Journal of Magnetics
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• v.18 no.3
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• pp.370-374
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• 2013

This paper introduces an innovative hybrid array consisting of both permanent and electro magnets. It will enable us to develop an active control mechanism for underdamped electro-dynamic suspension (EDS) Maglev systems. The proposed scheme is based on the Halbach array configuration which takes the major technical advantage from the original Halbach characteristics: a strongly concentrated magnetic field on one side of the array and a cancelled field on the opposite side. In addition, the unique feature of the proposed concept only differs from the Halbach array with permanent magnets. The total magnetic field of the array can be actively controlled through the current of the electro-magnet's coils. As a result, the magnetic force produced by the proposed hybrid array can also be controlled actively. This study focuses on the magnetic characteristics and capability of the proposed array as compared to the basic Halbach concept. The results show that the proposed array is capable of producing not only an equivalent suspension force of the basic Halbach permanent magnet array but also a controlled mode. Consequently, the effectiveness of the proposed array confirms that this study can be used as a technical framework to develop an active control mechanism for an EDS Maglev system.