• 한국환경성돌연변이발암원학회지
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• 제23권4호
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• pp.115-130
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• 2003

Idiopathic Parkinson's disease (IPD) represents a common neurodegenerative disorder. While epidemiological studies have suggested a number of risk factors including age, gender, race, and inherited disorder, the cumulative evidence supports the view that environmental or occupational exposure to certain chemicals may contribute to the initiation and progress of Parkinsonism. More recently, clinical and laboratory investigations have led to the theory that dysregulation of iron, an essential metal to body function, may underlie IPD by initiating free radical reaction, diminishing the mitochondrial energy production, and provoking the oxidative cytotoxicity. The participation of iron in neuronal cell death is especially intriguing in that iron acquisition and regulation in brain are highly conservative and thus vulnerable to interference from other metals that bear the similar chemical reactivity. Manganese neurotoxicity, induced possibly by altering iron homeostasis, is such an example. In fact, the current interest in manganese neurotoxicology stems from two primary concerns: its clinical symptoms that resemble Parkinson's disease and its increased use as an antiknock agent to replace lead in gasoline. This article will commence with addressing the current understanding of iron-associated neurodegenerative damage. The major focus will then be devoted to the mechanism whereby manganese alters iron homeostasis in brain.

• 천문학회보
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• 제37권1호
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• pp.99.1-99.1
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• 2012

Hapke의 양방향 분포 함수를 균일하게 입힌 실 크기 3차원 달표면 BRDF 모델을 이용한 달의 조도 수치모사 와 Big Bear Solar Observatory(BBSO)의 달빛 조도 관측 결과를 비교하였다. 1999년 9월 5일 UT9:30에서 UT12:30까지 지구상의 $34^{\circ}$ 15'30.04"N $116^{\circ}$ 55'16.49"W 위치에서 계산된 달의 조도가 관측된 조도와 1% 이내의 차이를 보이는 것을 확인하였다. 이후 검증된 달의 BRDF 모델과 램버시안 산란 지구 모델을 이용해 시간별 전 지구 알베도 추이를 광선 추적 수치 모사한 결과와 실제 BBSO에서의 측정결과 간 1% 이내의 차이를 보이는 것을 확인하여, .BRDF 모델과 광선추적 수치모사 기법의 타당성을 검증하였다.

• 천문학회지
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• 제47권6호
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• pp.311-317
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• 2014

Solar chromospheric surges are often reported to contain rotational motion. However, the details of the motion and driving mechanism of the surges are not yet fully understood. Recurrent surges with rotational motion at AR 10930 on the west limb are observed by Hinode Solar Optical Telescope (SOT) continuously from 11:21 UT on December 18 to 09:58 UT on December 19, 2006, using the $Ca_{II}$ H broadband filter. We analyze details of the motion including number of turns from the rise of the surge to the fall, axial speed and acceleration. During the observation, rise and fall motion accompanying rotation appears recurrently. There occur a total of 14 surges at AR 10930 over 17 hours. The average duration is 45 minutes, and the average width, and length are 8 Mm, and 39 Mm, respectively. We speculate that the surges occurred by recurrent reconnections between the twisted prominence and large untwisted flux tube.

• 천문학회보
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• 제42권2호
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• pp.61.3-61.3
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• 2017

We have studied the high-resolution $H{\alpha}$ and Ca II $8542{\AA}$ line profiles of Ellerman Bombs (EBs) obtained with the Fast Imaging Solar Spectrograph (FISS) installed on the 1.6m Goode Solar Telescope (GST) in Big Bear Solar Observatory (BBSO). The FISS spectra of EBs are compared with synthetic profiles computed using RH non-LTE radiative transfer code and a set of 1D atmospheric models with local transient heating, the latter of which is modeled by varying local temperature enhancement in magnitude and height. We could reproduce each of the observed $H{\alpha}$ and Ca II line profiles separately with different atmospheric models, but not with a single atmospheric model. To fit the observed $H{\alpha}$ lines we often need much higher temperature enhancements than those needed for fitting Ca II lines. Possible causes for this temperature mismatch are briefly discussed.

• Journal of Advanced Marine Engineering and Technology
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• 제32권1호
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• pp.131-136
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• 2008

The double-walled steel vessel with powder insulation in the space between the walls is used to minimize heat transfer by radiation and conduction in cryogenic storage tank. The vacuum required the insulation is much less extreme than with high-vacuum or multilayer insulations. The solid supports are used to bear the weight of the inner container. Thermal and structural analysis of the tank have been carried out to study the effect of vacuum and weldment geometry of the internal supports. Heat flux in wall is increased with increasing of thermal conductivity of perlite. Heat flux and stress of support is not affected by weldment geometry.

• 복식
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• 제21권
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• pp.19-30
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• 1993

There are record that ancient Korean WOOl fabrics male from sheep, camel, rabbit. bear, horse. calile, raccoon dog, fox and so on. Wool fiber fabriher were also reported Kye, Gal, China, Tap Dung, Kuyu anul ram. These wool fabrics wre named amongling to their fineness and weaving method in the fabric. Technology of wool fabric weaving was developed and from Sam Kuk dynasties to to Koryo Dynasty wool fabrics were reported to weave and trade to China, Japan and Arabia. These fabrics were mainly used as clothes, rugs or blankets. In Koryo Dynasty, especially Kye Kurn was used for trading goods to China. There is another record that two thousand sheep, camels offord Koryo by Yo and Kum Dynasty. In this study, the characteristics of Korean wool fabrics will be disscussed from the literature survey of the relevant references.

• Natural Product Sciences
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• 제6권3호
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• pp.151-153
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• 2000

Kampilla is an important herbal drug of indigenous system of medicine. Fruit dust of Mallotus philippensis Muell-Arg constitutes the genuine drug Kampilla. However, due to limited distribution of this plant and its high medicinal value, the drug is heavily adulterated with the cheaper substances. Hence the present study was undertaken to evaluate both the authentic and market samples. The drug consists of resin glands and trichomes. Resin glands are lined by a delicate yellowish thin membrane and bear a pore at the tip. Quantitative standards of the drug powder showed 82.50% yield in total ash while alcohol soluble extract of market and authentic sample exhibit 0.97% and 3.458% respectively. The main adulterant noticed in the market sample is brick powder. Simple methods are suggested to identify the genuine drug.

• Animal cells and systems
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• 제8권1호
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• pp.1-12
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• 2004

All copepodid stages and free-swimming adults of Ergasilus hypomesi Yamaguti collected from plankton samples from a brackish lake in Korea are described. The antennule remains a four-segmented appendage until copepodid V. The antenna of copepodid I carries a vestigial exopod. Sexual dimorphism first appears at copepodid IVwhose males bear primodial maxillipeds. Leg 5 also is sexually dimorphic from copepodid IV onwards, with its free segment bearing three setae in the female and two setae in the male. Morphological features of some appendages appearing during copepodid development are discussed. It is noticed that the early copepodids of the Ergasilidae show the characteristic setation on the biramous legs and proximal segments of the antennule.

• 산업경영시스템학회지
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• 제32권1호
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• pp.157-163
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• 2009

In every aspect of automotive production, quality, productivity and cost are crucial matters. The purpose of this research is to improve the productivity of slip yoke for automotive propeller shaft. This paper presents how to redesign the component that currently manufactured as forged one body type. Attention was focused on not only reducing processing time but insuring durability of the component simultaneously. In Automotive, propeller shaft is the device for transferring power from engine to axle via transmission, and the slip yoke is one of the main parts in the product. Propeller shafts are subject to torsion and shear stress, they thus need to be strong enough to bear the stress.

• Journal of Hospice and Palliative Care
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• 제8권2호
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• pp.234-244
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• 2005

As Korea has just turned into an aging society with the increase of average life expectancy, and the main causes of deaths is cancer and other chronic diseases. And this corresponds to a dramatic increase in medical expenses for the aged. To curve this problem, the hospice care can be an effective alternative, which can provide patients with both quality service and intensive care to help ensure high quality life for the patients. To demonstrate the economical effect of hospice services, a comparative study on the media expenses of geriatric hospitals and general hospitals, which bear similarities in common regarding the characteristics of their patients, is performed. Thus the results of the study can serve as a quantitative indication for the management of hospice services.