• Title/Summary/Keyword: MWO

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Solid-state metathetic synthesis of MWO4 (M=Zn, Co) particles assisted by microwave irradiation

  • Lim, Chang-Sung
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.20 no.6
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    • pp.295-300
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    • 2010
  • Metathetic route for the $MWO_4$ (M=Zn, Co) particles is a simple method of synthesis and a viable alternative method in a short time. $MWO_4$ (M=Zn, Co) particles were synthesized using solid-state metathetic (SSM) method with microwave irradiation. The $MWO_4$ (M=Zn, Co) particles were formed completely at $600^{\circ}C$ for 3 h. The crystallization process, thermal decomposition and morphology of the $MWO_4$(M= Zn, Co) particles were evaluated. The characteristics of the SSM reaction and the formation of a high lattice energy by-product NaCl were discussed.

MWO(Mobile Web Office) : Web based Knowledge Management System Design for Mobile Environment (MWO(Mobile Web Office) : 이동 환경을 위한 웹 기반 지식관리 시스템 설계)

  • Park, Yuri;Yoo, Seunghee;Cho, Dongsub
    • Proceedings of the Korea Information Processing Society Conference
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    • 2009.04a
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    • pp.11-14
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    • 2009
  • 위키는 사용자 누구나 문서를 생성하고 수정이 가능하여 지식관리 도구로 활용이 되고 있다. 위키는 사람을 대상으로 하는 지식 공동 저작과 공유를 위한 기반 구조 중 하나로서 웹에서 운용되며, 내용은 웹 문서 서식을 위한 간단한 마크 업 언어와 자연어로 구성된다. 이 논문은 minimal Apache server 를 USB 에 저장하여 사용할 수 있는 Dokuwiki 에 지식 기능들을 추가한 MWO(Mobile Web Office)를 제안한다. 휴대 성과 이식 성이 있다는 장점을 기반으로 하여 지식 기능들을 설계하여 더욱 효율적인 시스템을 제안한다. MWO 는 공통의 업무나 관련된 그룹의 구성원들이 정보들을 공유하고 시간적, 공간적 제약을 제거하고 그룹구성원의 팀워크와 작업생산성을 향상시킴으로써 업무효율을 증대하고 조직경쟁력을 강화할 수 있다.

Adaptive Radiation in the Cavity using Slot Antenna (캐비티내 슬룻안테나를 이용한 적응분사)

  • Kim, T.B.;Kim, S.G.;Park, Y.S.
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1896-1899
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    • 1997
  • In this paper, New radiation system is presented to improve efficiency and distribution of MWO. And it has one input for two excitatied lines with located on them radiation elements(slots). Radiation elements are distributed along the lines the way that the same electrical distances from the magnetron. New radiation system recompences change of impedance at wide b and frequency.

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Improvement of Field Uniformity in the Reverberation Chamber Using Diffusers Filled with Dielectric Material (유전체로 충진된 확산기를 이용한 전자파 잔향실 내의 전자기장 균일도 향상 연구)

  • Kim Hye-Kwang;Rhee Joong-Geun;Lim Wook-Chae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.12 s.103
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    • pp.1222-1228
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    • 2005
  • Analysis on the field uniformity inside of a reverberation chamber was done at 2.45 GHz which is an operating frequency of MWO(Microwave Oven). The Schroeder's Quadratic Residue Diffuser was designed for the chamber, and 3 different types of diffusers have been investigated using the finite-difference time-domain(FDTD) method for the field characteristics of each type. Type 2 and 3 diffusers were filled with dielectric material, and the size of these could be designed smaller than Type 1, without degradation of field characteristic. Type 3 diffuser shows better results among the three types of diffusers in view of increased test region and better field uniformity.

A 2.4 GHz 802.11b Throughput Estimation In a Noisy Environment Using an Experimental Noise Parameter

  • Hur Min-Ho;Lim Sung-Jin;Kwon Sewoong;Yoon Young-Joong
    • Journal of electromagnetic engineering and science
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    • v.5 no.2
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    • pp.61-65
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    • 2005
  • In this paper, a numerical permissible disturbance model is proposed to preserve a throughput performance of a 2.4 GHz wireless LAN service. The model is composed of two parameters, a peak value and a time rate of noise signal. The model parameters are experimentally determined from an APD parameter measurement. The APD parameter is measured by using the APD measurement method which is recommended from CISPR/A/447/CD.

Electromagnetic field analysis in MWO using computational method (수치해석을 이용한 전자렌지 내의 전자계 해석)

  • Park, Kwang-Soo;Shon, Jong-Chull;Kim, Sang-Gweon;Park, Yoon-Ser
    • Proceedings of the KIEE Conference
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    • 1997.07e
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    • pp.1893-1895
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    • 1997
  • This paper presents an analysis of the electromagnetic field in the 3D microwave oven using computational method. The model is accounted the real shape, including the formings, input waveguide with the magnetron, tray, and so on. For quantisation of this problem, Galerkin method with the Nedelec's edge basic functions is used. The system of linear algebraic equations is solved by the iteration method. The simulation results were compared with the experimental results.

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Generation of modern satellite data from Galileo sunspot drawings by deep learning

  • Lee, Harim;Park, Eunsu;Moon, Young-Jae
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.1
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    • pp.41.1-41.1
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    • 2021
  • We generate solar magnetograms and EUV images from Galileo sunspot drawings using a deep learning model based on conditional generative adversarial networks. We train the model using pairs of sunspot drawing from Mount Wilson Observatory (MWO) and their corresponding magnetogram (or UV/EUV images) from 2011 to 2015 except for every June and December by the SDO (Solar Dynamic Observatory) satellite. We evaluate the model by comparing pairs of actual magnetogram (or UV/EUV images) and the corresponding AI-generated one in June and December. Our results show that bipolar structures of the AI-generated magnetograms are consistent with those of the original ones and their unsigned magnetic fluxes (or intensities) are well consistent with those of the original ones. Applying this model to the Galileo sunspot drawings in 1612, we generate HMI-like magnetograms and AIA-like EUV images of the sunspots. We hope that the EUV intensities can be used for estimating solar EUV irradiance at long-term historical times.

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Study on the Analysis of Damage Patterns of Cellular Phone Batteries According to Energy Sources (에너지원에 따른 이동전화기 배터리의 소손패턴 해석에 관한 연구)

  • Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.25 no.6
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    • pp.21-26
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    • 2011
  • The purpose of this paper is to present the damage patterns of cellular phone (SCH_W830) batteries according to energy sources and have them utilized as data for the settlement of disputes between manufactures and consumers. The reliability was secured by maintaining the ambient temperature and humidity at $22{\pm}2^{\circ}C$ and 40~60 %, respectively. The voltage of the battery used for the tests was measured to be 4.18V between positive pole (+) and negative pole (-)(1), and 4.19 V between positive pole (+) and negative pole (-)(2). This study applied the Korean Industrial Standard (KS) to the flammability test of cellular phones due to a general flame applied to them and found that no damage occurred to the built-in battery even though the flame was applied to the cases of cellular phones for 30 seconds. From the results of immersing the cellular phones in the saline solution (NaCl, 0.9 %) for 180 seconds, it was found that there was a trace of carbonization and melting due to the heat caused by leaking current. It can be seen that when the cellular phones were heated for 70 seconds using a microwave oven (MWO), the areas containing the metal holder, recharging connector, antenna, etc., were melted and discolored and that other areas showed no particular problems. That is, while the external carbonization of cellular phones, built-in metals and dielectric materials, and damage and deformation of the battery terminal block, etc., occurred differently depending on the types of energy sources, the voltage showed comparatively constant characteristics. Therefore, it is thought to be possible to attribute the cause of damage to the battery by performing analysis taking into consideration comprehensively the characteristics of the flame spread pattern as well as the melting and deformation of metals.

A Study on Performance Reduction Characteristics of Digital Wireless Communication by APD (APD 통계 모델에 의한 디지털 무선 통신 성능 저감 특성 연구)

  • Lim, Sung-Jin;Hur, Min-Ho;Kwon, Se-Woong;Yoon, Young-Joon
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.8-12
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    • 2003
  • To protect digital communications and broadcasting that are expected to be increasingly used at frequencies above 1GHz, there is a need to determine permissible disturbance limits for frequency bands above 1GHz according to indicates that better correlates with interference level in digital systems. The quality of digital communications is expressed in terms of bit error rate(BER) or throughput. In this regard, it has been reported that degradation of BER or throughput can be estimated from the amplitude probability distribution (APD) of disturbance amplitude. Therefore, if the APD can simply be measured with a high accuracy, APD will be an optimal index for the assessment of interference in digital communications. In this paper, we show that a measurement method using statistic model of APD has compatibility about performance reduction estimation of WLAN. And through approach of this inspection, we propose numeral models about interference effects of peak value and time rate of spurious.

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