• 제목/요약/키워드: magnetic filed

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A Study on the Technical Regulation of Weak Electric Filed Strength Radio Equipment about 58kHz Frequency Band (58kHz 대역 미약 전계강도 무선기기 기술 기준에 관한 연구)

  • Park, Hyoung-Keun;Kim, Sun-Youb;Ra, Yoo-Chan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2319-2325
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    • 2009
  • This paper compared the output limits value of the Korean weak electric field strength wireless device in the 58kHz band with the standard values of foreign countries. Through this, the study confirmed that the Korean regulation was lower by about 50dB than those of the USA or Europe. In order to prove this, the study measured outputs by entrusting the 58kHz EAS system to two measuring companies. As a result of these measurements, electric field strengths were shown to be $112dB{\mu}V/m$ and $08dB{\mu}V/m$ respectively, and these values were confirmed to exceed the current Korean standard of $102.7dB{\mu}V/m$. Accordingly, it is deemed necessary to review the specifications of the Korean standard in the 58kHz band.

Development of MRI Simulator Early Diagnosis Program for Self Learning (자가 학습을 위한 MRI Simulator 초기 검사 프로그램 개발)

  • Jeong, Cheon-Soo;Kim, Chong-Yeal
    • The Journal of the Korea Contents Association
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    • v.15 no.9
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    • pp.403-410
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    • 2015
  • Since 1970, MRI has greatly been developing in terms of strength of magnetic field, the number of receipt channels, and short time of examination. With the development of digital systems and wireless network, hospitals have also acquired, saved, and managed digital images taken by various kinds of medical imaging equipment. However, domestic universities fail to provide practice training course independently thanks to expensive practice equipment and high maintenance cost, and rely on clinical training. Therefore, this study developed a MR patient diagnosis program based on Windows PC to help out students before their working in clinical filed. The designed Relational Database of MRI Simulator is made up of seven tables according to functions and data characteristics. Regarding the designed patient information, each stepwise function was classified by the patient registration method in clinical field. In addition, on the assumption of the basic information for diagnosis, each setting and content were classified. The menu by execution step was arrayed on the left side for easy view. For patient registration, a patient's name, gender, unique ID, birth date, weight, and other types of basic information were entered, and the patient's posture and diagnosis direction were set up. In addition, the body regions for diagnosis and Pulse Sequence were listed for selection. Also, Protocol name and other additional factors were allowed to be entered. The final window was designed to check diagnosis images, patient information, and diagnosis conditions. By learning how to enter patient information and change diagnosis conditions in this program, users will be able to understand more theories and terms learned in practice and thereby to shorten their learning time in actual clinical work.

CO Observations Toward IRAS 07280-1829 and Its Related Clouds (적외선원 IRAS 07280-1829와 이와 관련된 분자운의 CO분자선 관측연구)

  • Lee, Chang-Won
    • Journal of the Korean earth science society
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    • v.32 no.4
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    • pp.402-410
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    • 2011
  • We present results of CO observations toward an infrared (IR) source, IRAS 07280-1829, and its possibly related molecular clouds. The physical parameters of this IR source such as its infrared slope (${\alpha}$=16) of the Spectral Energy Distribution and bolometric temperature (145 K) indicate that it is an embedded protostar. Its luminosity is ${\sim}2.9{\times}10^4L_{\odot}$, typical of a massive star. The CO profile toward IRAS 07280-1829 has broad wing components, implying a possible existence of CO outflow. The excitation temperature and mass of a molecular cloud (Cloud A) which is thought to harbor the IR source are estimated to be 9~22 K and ~180 $M_{\odot}$, respectively, indicating the Cloud A is a typical infrared-dark cloud. Its LTE mass is found to be much smaller than its virial mass by more than a factor of 10 which is inconsistent with the fact that a protostar recently formed exists in the Cloud A. This may suggest that the environment of the cloud where the IR source is forming is dominant of turbulence and/or magnetic filed, making its virial mass estimated unusually high.

Synthesis of Prussian Blue Analogue and Magnetic and Adsorption Characteristics of MnFe2O4 (프러시안 블루 유사체의 합성 및 MnFe2O4의 자성과 흡착 특성)

  • Lee, Hye-In;Kang, Kuk-Hyoun;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.33 no.1
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    • pp.67-74
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    • 2016
  • The Prussian Blue Analogue(PBA) has three dimensional structure and the metal - organic framework material, and it has a variety configurations depending on the type of organic ligands. PBA has been receving an attention in the fields of biosensors, optical, catalytic, and hydrogen storage device. Also, it is an environmental friendly substance with a chemical stability. In addition, PBA is widely used in the filed of adsorption art since we can adjust the size of the fine pores. In this study, we synthesized $Mn_3[Fe(CN)_6]_2$, an organometallic framework chains by using a hydrothermal synthesis method. We used $K_4[Fe(CN)_6]$ and $MnCl_2$ as precursors. We also produced a manganese iron oxide, by baking the synthesized material. The effect of the size and shape of the particles was examined by controling pH of the precursor solution, the molar concentration of the precursor, and reaction time as the experimental variables. Synthesized absorbent was analyzed by XRD, SEM, FT-IR, UV-Vis, and TG / DTA to evaluate the adsorption properties of several dyes.

Multi-purpose Geophysical Measurements System Using PXI (PXI를 이용한 다목적 물리탐사 측정 시스템)

  • Choi Seong-Jun;Kim Jung-Ho;Sung Nak-Hun;Jeong Ji-Min
    • Geophysics and Geophysical Exploration
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    • v.8 no.3
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    • pp.224-231
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    • 2005
  • In geophysical field surveys, commercial equipments often fail to resolve the subsurface target or even sometimes fail to be applied because they do not fit to the various field situations or the physical properties of the medium or target. We developed a geophysical measurement system, which can be easily adapted for the various field situations and targets. The system based on PXI with A/D converter and some stand alone equipment such as Network Analyzer was applied to borehole radar survey, borehole sonic measurement and electromagnetic noise measurement. The system for borehole radar survey consists of PXI, Network Analyzer, dipole antennas, GPIB interface is used for PXI to control Network Analyzer. The system for borehole sonic measurement consists of PXI, 24 Bit A/D converter, high voltage pulse generator, transmitting and receiving piezoelectric sensors. The electromagnetic noise measurement system consists of PXI, 24 Bit A/D converter, 2 horizontal component electric field sensors and 2 horizontal and 1 vertical component magnetic filed sensors. The borehole radar system has been successfully applied to detect the width of the artificial tunnel through which the borehole pass and to image buried steel pipe, while the commercial borehole radar equipment failed. The borehole sonic system was tested to detect the width of artificial tunnel and showed a reasonable result. The characteristic of electromagnetic noise was grasped at an urban area with the data from the electromagnetic noise measurement system. The system is also applied to characterize the signal distortion by induction between the electric cables in resistivity survey. The system can be applied various geophysical problems with a simple modification of the system and sensors.