• Journal of Magnetics
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• 제22권2호
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• pp.291-298
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• 2017

In this paper, the distribution of internal magnetic induction intensity of oil-film bearing twined solenoids was proposed. The magnetic field was generated by solenoids and magnetized bearing. The magnetized bearing was simplified as solenoid model. The mathematical model of magnetic induction intensity at any point of finite solenoid was deduced. Through experiment method, the distribution of the internal magnetic induction intensity of oil-film bearing and the magnetizing current formula of bearing was obtained. Further, the magnetic induction intensity distribution of magnetization bearing was solved successfully. The results showed that the magnetic induction was a second-degree parabola with open upwards along the axial plane and the distribution of magnetic induction intensity was opposite to the rule of magnetic induction intensity generated by solenoids. In addition, the magnetic flux density increased linearly with the increase of current.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2006년도 공동학술대회 논문집
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• pp.141-151
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• 2006

차량이 자력계를 끌면서 자기장을 측정하는 자력탐사시스템에서 차량 자체가 발생하는 잡음으로서의 자기장을 제거하기 위한 실험을 하였다. 차량 자체의 잔류자기 및 유도자기를 추출하기 위하여, 먼저 자력계를 고정된 점에 두고 차량을 이동하면서 자기장을 측정하였고, 이 자료로부터 차량을 고정된 점에 두고 자력계를 이동하면서 측정한 자료로 만들었으며, 후자의 자료로부터 역산을 통하여 차량 자체의 잔류자기 및 유도자기를 계산하였다. 한편, 차량 자력탐사시스템으로 측정한 각 측점의 자료로부터, 역산으로부터 계산한 차량 자체의 잔류자기 및 유도자기에 의해 발생하는 잡음으로서의 영향을 벡터적으로 제거 즉, 보정하여 자력이상을 추출하였다.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1992년도 추계학술대회논문집
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• pp.77-83
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• 1992

The effect of magnetic field on VDT work has not been clarified yet, but many studies repoerted that magnetic field could cause of the cancers. Many developed countries have set the criteria of magnetic field and produce the VDT which has lower magnetic value. The purpose of this study was to measure the intensity of magnectic field from VDT. For this purpose three experiments were performed. The first was designed to measure the intensity of magnetic field by distances(30,60,90 cm) and directions. The second was to compare the intensities between VDT and Color TV. The last was to evaluate the eye protec- tion glasses. The reults showed that the intensity of magnetic field was lowered in proportion to the distance $r^{3}$and both lateral sides of the VDT marked high values compared to the frontal and back sides. On the same distance (30 cm) color TV marked high value to the VDT. But on the normal work distance (TV: 100 cm, VDT: 30 cm) there was little difference, Eye protection glasses could not protect the magnetic field physically.

• 전기학회논문지
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• 제59권10호
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• pp.1803-1808
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• 2010

Electric railway system consists of rolling stock, track, signal and catenary system. ATP system in railway signaling system is the important one grasping the position and velocity of a train. The wayside device of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board device and wayside device is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmission distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic field intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic field intensity from the wayside device to on-board device is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program. Also, BER according to the train speed is presented by calculating electric field intensity from the magnetic field intensity.

• Current Optics and Photonics
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• 제6권3호
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• pp.337-343
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• 2022

Microfluidic chips are new devices that can manipulate liquids at the micrometer level, and terahertz (THz) time-domain spectroscopy has good applicability in biochemical detection. The combination of these two technologies can shorten the distance between sample and THz wave, reduce THz wave absorption by water, and more effectively analyze the kinetics of biochemical reactions in aqueous solutions. This study investigates the effects of different external magnetic field intensities on the THz transmission characteristics of deionized water, CuSO₄, CuCl₂, (CH₃COO)₂Cu, Na₂SO₄, NaCl, and CH₃COONa; the THz spectral intensity of the sample solutions decrease with increasing intensity of the applied magnetic field. Analysis shows that the magnetic field leads to a change in the dipole moment of water molecules in water and electrolyte solutions, which enhances not only the hydrogen-bond networking ability of water but also the hydration around ions in electrolyte solutions, increasing the number of hydrogen bonds. Increasing the intensity of this magnetic field further promotes the hydrogen-bond association between water molecules, weakening the THz transmission intensity of the solution.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1656-1662
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• 2010

Automatic train control systems are divided into ATC, ATP and ATS systems etc. The ATP and ATS systems offer discontinuous information for train control. While the ATC systems provide continueous information for train control. There is a method for offering continuous information by AF track circuits. Magnetic fields are formed by current through rails in the AF track circuit systems. So, the continuous information is received by the magnetic fields on a on-board antenna. Coating materials on rails are researched to decrease defects such as head check, shelling, corrugation, squats and so on in Germany. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. When deciding physical characteristic of ceramics, researches are required about variation of flux density by the ceramics. In case that the flux density is much lower than existing value, the information for train control is not transmitted to the on-board antenna. In this paper, inductance on rails is calculated and a model is presented about variation of the magnetic field intensity in the AF track circuit. Standard permeability of ceramics is proposed by analyzing the variation of magnetic field intensity. It is demonstrated by using Maxwell and Matlab program.

• 대한의생명과학회지
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• 제10권2호
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• pp.115-120
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• 2004

To investigate the correlation between the magnetic resonance imaging (MRI) of cerebral fat embolism that is induced by injecting oleic acid into 10 cats, and a pathologic diagnosis. Using a microcatheter, 30 ${mu}ell$ of oleic acid was injected into the internal carotid artery of 10 cats. MR T2-weighted image (T2WI), diffusion-weighted image (DWI) and Gadolinium-enhanced T1-weighted image (Gd-enhanced T1WI) were obtained after 30 minutes and 2 hours of embolization. After 30 minutes of the embolization, lesions of very high signal intensity were detected by T2WI in 6 cats, and of slightly high signal intensity in 2 cats; in the remaining 2 cats, signal intensity was normal. DWI showed lesions of very high intensity in 9 cats and of slightly high intensity in one cat. According to the findings of light microscopic examination, infarcted lesions mainly involved the gray matter, but also some white matter. A magnetic resonance imaging diagnosis for cerebral fat embolism that was induced by oleic acid through the internal carotid artery in cats showed high signal intensity on the T2WI and the DWI within an initial 2 hours, and with a well enhancement on the Gd-enhanced T1WI. Considering cellular edema, cerebrovascular injury and extracellular space widening, we assumed pathologically that cytotoxic and vasogenic edema exists at the same time.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.191-195
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• 2001

The applications of magnetic fluid can be normally made by 1) using changes of a property of matter caused by applied magnetic field; 2) preserving magnetic fluid at a certain position or in a magnetic fluid keeping the body in a floating condition; 3) controlling the flow of magnetic fluid by means of magnetic field. However, these are usually made by using their methods together. In this study, the natural convection flow of a magnetic fluid in annular pipes is experimentally analyzed. High temperature is kept constantly inside of a circular pipe of experimental model, on the other hand, low temperature is kept constantly outside of it. In experiments, several cases are carried out in order to clarify the fluence of direction and intensity of magnetic fields on the natural convection of magnetic fluid. Therefore magnetic fields are applied in various intensity and up and down directions by permanent magnets.

• 대한기계학회논문집B
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• 제37권7호
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• pp.637-646
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• 2013

본 연구에서는 밀폐된 정방형관 내에서 자성유체의 자연대류현상에 대하여 수치해석적으로 접근하였다. GSMAC(Generalized-Simplified Marker and Cell method)법을 이용하여 자성유체의 지배방정식을 풀었으며 외부에서 인가자장의 세기 및 방향에 따른 자연대류현상과 열전달 특성을 수치해석적으로 규명하였다. 자성유체의 자연대류현상은 인가자장의 세기 및 방향에 따라 제어되었다. 자장이 수직방향으로 인가될 경우 자장의 세기 H가 4000일 때 평균 Nusselt 수가 최소가 되었고 자장이 수평방향으로 인가될 경우 자장의 세기 H가 12000일 때 평균 Nusselt 수가 최소가 되었다. 또한, 이 지점을 기준으로 자장의 인가방향과 관계없이 자장의 세기가 증가할수록 평균 Nusselt 수가 증가하였다.

• Investigative Magnetic Resonance Imaging
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• 제19권3호
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• pp.200-204
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• 2015

Image findings of hepatic lymphoma have been reported as variable, ranging from single or multiple small nodules to diffuse infiltrative patterns. On MRI, most hepatic lymphomas show T1 low signal intensity, T2 high signal intensity. Dynamic imaging reveals a hypointense appearance in the arterial phase, followed by delayed enhancement in the portal venous and transitional phase. In the hepatobiliary phase using a hepatocyte-specific contrast agent (which have recently aided in increasing the access to the focal liver lesions), hepatic lymphoma is known to exhibit low signal intensity. We report a case of hepatic lymphoma, which shows iso-signal intensity on hepatobiliary phase, using gadoxetic acid (Gd-EOB-DTPA).