• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1113-1115
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• 2002

Mesoporous silica, MCM-41, was synthesized by sol-gel method. The organic structure-directing agent must be removed to make the desired proes. To achieve this, alternative calcination method using microwave oven was adapted to this removal stage. Microwave calcination was shown to provide a novel, rapid and inexpensive method of praparing nanoporous material. It was studied how the porous structure, surface area and pore size distribution were changes under microwave calcination.

• Journal of Biomedical Engineering Research
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• v.27 no.6
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• pp.357-364
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• 2006

Microwave Radiometry is the spectral measurement of eleclromagnetic radiation at frequency bands in the microwave region. One particular application of Microwave Radiometry is for analyzing temperature difffrentials of inside of human body to detect and diagnose pathologic conditions in which the temperature differentials are related with the symptoms of certain diseases. To accomplish this aim, we propose a new calibration method for estimating subcutaneous temperature by Microwave Radiometer and we also suggest a tumor-imitator phantom structure for simulating heat diffusion propagated by tissues around tumors to evaluate the discernment of brighuless temperature difffrentials.

• Journal of the Korean Ceramic Society
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• v.48 no.6
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• pp.577-583
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• 2011

Stabilized biocompatible superparamagnetic iron oxide nanoparticles (SPIONs) were prepared by controlled coprecipitation method for hyperthermia application. ESR measurements determined that all of the interactions in the individual SPIONs (1 nm and 11 nm) were antiferromagnetic in nature because the ions contributed to the magnetization with a range of magnetic moments. In-situ monitoring of the temperature increment was performed, showing that the microwave absorption rate of the SPIONs was dispersed in an appropriate host media (polar or non-polar solvents) during microwave irradiation. Microwave absorption energy rates and heat loss of SPIONs in solvent were calculated by non-linear data fitting with an energy balance equation. The microwave absorption rates of SPIONs dispersed in solvent linearly increases when the concentration of SPIONs increases, implying that the microwave absorption rate can be tunable by changing the concentration of SPIONs.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.329-334
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• 2003

Backgound: Cryoablation and radiofrequency ablation have been used to treat the atrial fibrillation. Some reports insisted that the microwave ablation Is a better method for a deep and extensive lesion. Material and Method: From December 2001 to July 2002, we peformed 8 microwave ablations in patients who needed mitral valve surgery (7 MVR, 1 MVR+AVR). There were 3 men and 5 women, and their mean age was 43.4$\pm$8.3 years and mean follow up period was 5.6$\pm$2.4 months respectively. The microwave was applied on endocardium or epicardium by Lynx (Afx, inc.) using a power of 45 watts for 25 seconds. We studied the left atrial dimension, the left atrial function and the sinus conversion with echocardiography and electro-cardiography at three times; 1) before the operation, 2) immediately after the operation, and 3) 6 months after the operation. Result: There was no complication and no mortality. The mean aortic clamping time was 104.6$\pm$25.0 minutes, and the mean total bypass time was 130.5$\pm$28.7 minutes. The rate of sinus conversion was 75%, A wave across the mitral valve was a mean of 77.0$\pm$24.8 cm/sec, and the AVE was a mean of 0.46$\pm$0.17 at 5.6 months postoperatively Conclusion: There was no difference in the early result of microwave ablation compared to other methods. The microwave ablation was an acceptable method due to its convenient application especially in beating heart.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.788-791
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• 2008

ZnO nanoparticle was successfully prepared by microwave irradiation method in various oxygen/nitrogen ratio atmospheres. The product prepared in a low oxygen ratio atmosphere showed tetra pod shape with high aspect ratio, c/a. PL spectra of the products showed higher UV emission intensity than the others when it was prepared in the atmosphere oxygen/nitrogen=40/60.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.6
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• pp.935-950
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• 1999

A multiresolution time-domain analysis scheme is derived for the analysis of microwave structures by using Haar wavelets to discretize the Maxwell's curl equation. This technique requires less computational effort than the conventional FDTD method because larger space grid can be used in the simulations. To validate this scheme, several 2-D·3-D microwave structures are simulated and the results are compared with those of the conventional FDTD scheme.

• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2963-2967
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• 2013

This paper describes a simple and efficient method involving domino Knovenegal/$6{\pi}$ electrocyclization for the preparation of a variety of 2H-pyrans using microwave irradiation under solvent- and catalyst-free conditions. This method offers the advantages of a green approach, high yields, and short reaction times. Sixteen compounds (9a-p) were obtained in good to excellent yields using the procedure.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.556-561
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• 2008

The characteristics of microwave reflectometry, which is based on the technologies of FM radar and is applied as a non-invasive method to examine the properties including density distribution of inhomogeneous media, is investigated. The microwave reflectometry system requires not only an optimized system hardware but as well as the understanding of system response from the media under test in order to provide the system solution describing the object under test quantitatively. The introduction of microwave reflectometry especially in the area of applied plasma physics has been relatively new and the number of usage is found to be increasing gradually. The experimental method to characterize the microwave system as a device to examine the properties of plasma is explained. The microwave reflectometry signals consist of the cutoff signals which originate from the region where most of the reflected power comes from and the scattered signals which result as an interaction of the microwave and the density perturbations. This paper describes the experimental results of the scattered signal from the microwave reflectometry, such as the wavenumber dependence and the sensitivity on density perturbation, and the comparison of the characteristics with those from the numerical simulations and those from the cutoff signals.

• Journal of the Korean GEO-environmental Society
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• v.12 no.5
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• pp.5-12
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• 2011

Water content is one of the significant engineering properties of soil for predicting the behavior of soil matrix. Conventional drying oven can be widely used to obtain the values by drying the soil specimens for 16 to 24 hours at $105^{\circ}C$. Although a number of experimental data has been accumulated for the conventional method of drying soil for water contents, shortcomings of the method are still hard to overcome such as long drying time for in situ use and the difficulty of taking prompt actions against emergency cases. Recently, ASTM and JGS have established microwave oven drying techniques for obtaining water contents to cope with those problems. And the reliability evaluation study has been also performed on the microwave oven drying for water contents. Feasibility study of the microwave oven drying was performed to confirm the process of the technique with Jumunjin sand, kaolinite, bentonite, weathered granite soil, and organic soil. Investigation was also conducted on the factors affecting and enhancing the reliability of the technique.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.109-110
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• 2022

Currently, interest in the quality of concrete is increasing. Among the important factors for evaluating the quality of concrete, interest in unit-water content is also increasing. Currently, the air-meter method, the microwave oven drying method, the capacitance method, and the microwave penetration method are used to measure the unit-water content of concrete.. Among the above methods, except for the microwave method, the measurement method is complicated, portability is reduced, and economic efficiency is reduced. This research aims to measure a unit-water content by using a Frequency Domain Reflectometry(FDR) sensor that is economical, simple to measure, and portable among microwave methods. In addition, it is an experimental study to determine the accuracy of unit-water content using a single input residual model during deep learning to solve the limitations of the FDR sensor.