• 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.

• 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.

• 조명전기설비학회논문지
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• 제16권6호
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• pp.51-59
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• 2002

논문은 가전기구의 사용으로 발생하는 유도전압 및 자장의 측정과 분석에 대한 것으로 본 실험에 사용한 유도전압과 자장 측정회로는 유도코일, 선행증폭기, 그리고 능동적분기로 구성하였다. TV와 퍼스널 컴퓨터용 모니터는 스위칭소자로 동작하는 전원장치를 사용하므로 고조파 성분을 많이 포함하는 강한 자장과 유도전압을 발생시켰다. 14"TV 주변에서 큰 자장과 높은 유도전압이 나타났고, 그 값은 측정거리 0.4 ［m］에서 각각 2.1 ［$\mu$Tp-p］와 140［mVp-p］이었다. 그러나 동일한 측정거리에서 단위 자장의 세기에 대한 유도전압은 17"모니터에서 약560 ［mV/$\mu$T］로 가장 크게 나타났다.장 크게 나타났다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.927-929
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• 2014

MRE(Magneto-rheological Elastomer) is a material which shows reversible and various modulus in magnetic field. Comparing to conventional rubber vibration isolator, MREs are able to absorb broader frequency range of vibration. These characteristic phenomena result from the orientation of magnetic particle (i.e., chain-like formation). Magnetic reactive powder(MRP), having rapid magnetic reaction, was selected as a magnetic particle to give magnetic field reactive modulus. The mechanical properties of manufactured MREs were measured with the application of magnetic field. The analysis of MR effect was carried out by FFT analyzer with various induced current. As induced magnetic field intensity increased and coated with MRP, increment of MR effect was observed.

• 한국연소학회지
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• 제17권1호
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• pp.58-65
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• 2012

The influence of magnetic field on propane and acetylene diffusion flames have been experimentally investigated using an electromagnetic system. Periodically induced magnetic field having various frequencies and duty ratios was established in square wave form. The maximum intensity and gradient of magnetic field were 1.3 T and 0.27 T/mm, respectively. The width of a propane flame was reduced up to 4.5% and the brightness was enhanced up to 25% when the magnetic field was induced. The soot emission from an acetylene flame was ceased when magnetic field was induced. The alteration of flow field, which is due to the paramagnetic characteristics of oxygen molecule, is most likely to be responsible for the change in flame size and brightness. The effect of magnetic field on diffusion flames, which competes with the gravitational effect, was more apparent from a smaller size flame. The magnetic field effect, therefore, could be important under microgravity conditions. Since the time required to alter the flow field must be finite, the magnetic field effect is likely to be less significant for a periodically oscillating magnetic field at a high frequency or having a small duty ratio.

• 한국안전학회지
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• 제8권3호
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• pp.34-43
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• 1993

This paper presents a study on the characteristics and safety criteria for human body in ELF (Extremely Low Frequency : 50-60Hz) electric and magnetic fields. Many researches for ELF electric and magnetic fields, which are developed in the past, are studied and analyzed In this paper. In order to estabilish the safety criteria for human body in the field, the field intensity, induced current and voltage are calculated by the electrostatic field approach which is far simpler than the electromagnetic field one based on Maxwell equation. The method is applied to the 345 KV transmission line system In operation and 765 KV system under consideration. According to the results, the maximum value of field intensity, 6.8627KV/m, is evaluated at the location which is 14m away from transmission line. As the safety criteria value by the abroad researches asserting that the human can detect the Induced current in 6KV/m and above, 5KV/m and 7KV/m are recommended at residence area and nonresidence area, respectively.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.288-291
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• 2014

MRE(Magneto-rheological Elastomer) is a material which shows reversible and various modulus in magnetic field. Comparing to conventional rubber vibration isolator, MREs are able to absorb broader frequency range of vibration. These characteristic phenomena result from the orientation of magnetic particle (i.e., chain-like formation) in rubber matrix. In this study, Silicon was used as a matrix in order to manufacture MREs. Magnetic reactive powder(MRP), having rapid magnetic reaction, was selected as a magnetic particle to give magnetic field reactive modulus. The mechanical properties of manufactured MREs were measured with the application of magnetic field. The analysis of MR effect was carried out by FFT analyzer with various induced magnetic field. As the addition of CIP and induced magnetic field intensity increased, increment of MR effect was observed.

• 한국산업융합학회 논문집
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• 제7권1호
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• pp.129-132
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• 2004

In order to determine the effective way of measuring the Mode I stress intensity factor, $K_I$, by means of the alternating current potential drop(ACPD) technique for a material containing a two-dimensional surface crack, the change in magnetic flux density above the cracked specimen surface was studied experimentally. The change in magnetic flux in the air above the cracked specimen made of aluminum alloy is measured by changing the load by four-point bending. The magnetic flux in the air is almost not changed by increasing the load in teh specimen. The change in potential drop due to load is not caused by the change in electro-motive force induced in the coiled measuring system. This experimental result agree to the result of theoretical analysis in reference 7).

• Investigative Magnetic Resonance Imaging
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• 제24권1호
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• pp.46-50
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• 2020

Radiation-induced lumbosacral plexopathy (RILSP) is an uncommon complication of pelvic radiotherapy that can result in different degrees of sensory and motor deficits. An age 59 female with cervical cancer, who had received combined chemotherapy and radiation therapy two years before, presented with bilaterally symmetric lower-extremity weakness and tingling sensation. The magnetic resonance imaging showed diffuse T2 bright signal intensity and mild enhancement along the bilateral lumbosacral plexus with no space-occupying masses. RILSP was diagnosed after the exclusion of malignant and inflammatory plexopathies.

• 한국자기학회지
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• 제10권1호
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• pp.42-47
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• 2000

본 논문에서는 원관내 횡방향 자장을 인가한 경우에 자성유체의 유동을 이론적으로 연구하였다. 이론식 도출에 있어서 Eringen의 극성이론과 Shliomis에 의해 유도된 지배방정식을 사용했다. 자기적 응답으로서 속도, 와도, 각속도의 분포 및 이론식을 통해서 자성유체는 비뉴우톤 유체임을 나타낸다. 또한, 인가자장이 종방향일때와 비교해서 자성유체의 동적특성을 조사한다. 즉, 자성유체에 영향을 주는 자장의 범위를 극성, 치수 및 자성효과 파라미터를 이용해서 조사한다.