• 전기기술인
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• 제195권11호
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• pp.16-22
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• 1998

연료전지의 개발은 1839년 영국의 Grove경이 그 원리를 실험으로 제시한 이래 1965년 미국의 우주계획에서 제미니호의 전원으로 채택되어 최초로 실용화 되었으며 70년대 초 오일파동 이후 본격적으로 전기사업용으로의 개발이 진행되어 현재 미국, 일본 등 선진국에서는 MW급 발전용연료전지의 실용화를 목적에 두고 있다.

• 대한수학회보
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• 제35권1호
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• pp.189-193
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• 1998

In this paper we construct a sequence of spaces which has Gromov-Hausdorff limit such that a geodesic in the limit space is not realized as a limit of geodesics in the spaces of the sequence. This contrasts with the result of Grove and Petersen in [1] where they proved otherwise for Alexandrov spaces with common curvature bounds.

• 대한수학회보
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• 제42권3호
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• pp.543-554
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• 2005

In this paper it is proved that for p-hyponormal or log-hyponormal operator A there exist an associated hyponormal operator T, a quasi-affinity X and an injection operator Y such that TX = XA and AY = YT. The operator A and T have the same spectral picture. We apply these results to give brief proofs of some well known spectral properties of p-hyponormal and log­hyponormal operators, amongst them that the spectrum is a con­tinuous function on these classes of operators.

• 대한수학회보
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• 제42권3호
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• pp.571-577
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• 2005

In this paper we prove that if T is a k-th root of a p­hyponormal operator when T is compact or T$^{n}$ is normal for some integer n > k, then T is (generalized) scalar, and that if T is a k-th root of a semi-hyponormal operator and have the property $\sigma$(T) is contained in an angle < 2$\pi$/k with vertex in the origin, then T is subscalar.

• 대한수학회보
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• 제43권4호
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• pp.671-677
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• 2006

Let $A, B{\in}B(H)$ be Hilbert space contractions, and let ${\Delta}_{AB}$ be the elementary operator ${\Delta}_{AB}:X{\rightarrow}AXB-X$. A number of conditions which are equivalent to '${\Delta}_{AB}$ has closed range' are proved.

• Mycobiology
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• 제29권1호
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• pp.61-62
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• 2001

Anthracnose symptoms on young cabbages were found in cabbage nursery fields in Jangheung area of Korea in 1998. The symptoms developed on seedlings, leaves, and stems of young cabbages(Brassica oleracea var. capitata L.). The casual fungus was identified as Calletotrichum dernatium(Fr.) Grove based on morphological and cultural characteristics. Similar symptoms were observed on the cabbage when artificially inoculated on the plant leaves. The fungus was reisolated from the symptoms of the inoculated plant.

• 한국조경학회지
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• 제30권1호
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• pp.11-17
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• 2002

This paper compares the difference between the village groves in the Jinan settlement region and the Hamyang settlment region in Honam and the Youngnam mountainous region. The results are as follows: Fifty-one village groves in the Jinan legion were found and 40 village groves were found in the Hamyang region. It was established that the village groves in the Jinan region of Honam province were conserved better than those of Hamyang region of Youngnam province. In the Jinan area, the village groves were principally found in the Jinan-eup and the Hamyang regions, primarily in Seosang-myun and Aneui-myun. So it was determined that the village groves were distributed inequitably in the two regions. In L / W ratio, the Jinan region is 3.6 and Hamyang region is 2.0 Jinan is 1.8 times greater than Hamyang. Therefore, it was concluded that Jinan is stronger than Hamyang in linear function of the village groves. Stone stooge for complementation function was found in 11 village groves in the Jinan region and 6 village groves in Hamyang. So the percentage of the remaining stone storage is 15-20 % of all village groves. Regarding grove makeup, the village gloves in Jinan region is deciduous forest principally. In contrast, the groves of Hamyang are principally coniferous forest. The dominant tree of the Jinan-gun region is Zelkova serrata, but in Hamyang it is Pinus densiflrora. By number, Hamyang region has two times the trees than Jinan region. In density of stand, the Hamyang region is 76.2% higher than Jinan region. In height and diameter of trees, the Jinan region is greater than the Hamyang region. It was identified that RSI of both region is 40%. So in density of trees, both region are sparse. This paper has a limit in ideiltiting the differences between Yolmg-nam ar\ulcorner Hnam village groves because comparative review only examined two regions.

• 한국토양비료학회지
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• 제49권6호
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• pp.635-643
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• 2016

Wine consumers desire to drink a high quality wine. For producing high quality wine, high quality soil is required. Conventionally, soil quality is assessed qualitatively. Using traditional laboratory methods, quantitative data can be obtained for management purpose, but it is time consuming and expensive. Therefore, new technology aims to address these limitations, namely portable X-Ray fluorescence spectrometers (pXRF). This instrument can be used directly in the field, requires no soil sample preparations, and can simultaneously measure a wide range of elements qualitatively that are useful for pedological studies. The chemical composition (Ca, Fe, Ti and Zr) of soils at Tallavera Grove vineyard in New South Wales, Australia, was studied using a pXRF. The analysis of the soil's elemental concentration (i.e. Ca and Fe) using pXRF supports management decisions. Measuring the soil's Ca concentration can be used to identify Ca-rich parent materials (limestone). The limestone indicates good soil conditions for vine production. Fe content was used to identify areas of texture-contrast soils or soil with accumulation of clays in the B horizon. In addition, a soil weathering index was calculated using elemental concentrations (i.e. Ti and Zr) to explore the history of soil formation for making decision of management. This index showed that the soil in the vineyard was affected by two processes: the deposition of materials from elsewhere (Aeolian transport or soil erosion) and mixing of materials from upslope.

• Journal of Ecology and Environment
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• 제31권4호
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• pp.333-339
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• 2008

We investigated death rates, growth rates and recruitment of culms in two neighboring bamboo (Phyllostachys bamboosoides) stands nested in by two different bird species to analyze stand structure and to design conservation strategies. A third bamboo grove not used by birds, the Taewha stand, was included as a control stand. The bamboo stand occupied by birds in the family Ardeidae (the Ardeidae stand) had an approximately 1.5 times higher culm density than the stand occupied by birds in the family Corvidae (the Corvidae stand). The crude death rate and the number of newly emerged shoots were also higher in the Ardeidae stand than the Corvidae stand. The death rate for bamboo in the Ardeidae stand was not dependent on diameter at breast height (DBH) and was almost 40% for culms of all sizes, whereas most dead culms in the Corvidae stand were < 4 cm DBH. Consequently, we conclude that in the Ardeidae stand, density-independent causes of death are operating, while density-dependent factor are more important in the Corvidae site. The results of soil analysis in these stands suggest that the density-independent death pattern observed in the Ardeidae stand may be due to soil acidification resulting from wastes produced by the birds during breeding. On the other hand, the culm distribution and death patterns in the Corvidae stand suggest that the stand characteristics were not affected by the nesting birds. These results suggest that different conservation strategies must be applied to conserve bamboo groves used by ardeids and corvids for nesting.

• 한국식물병리학회지
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• 제2권1호
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• pp.31-36
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• 1986

구기자(Lycium chinense Mill) 탄저병은 구기자 열매에 수침상의 흑색 병반을 형성하고 포자층을 형성한다. 일반농가 포장에서의 발병율은 $0.8\%\~23\%$(평균 $9.6\%$)의 이병과율을 보였다. 구기자 탄저병균은 Colletotrichum gloeosporioides Penz와 Colletotrichum dematium(Fr.) Grove의 2종으로 동정되었다. 구기자에 대한 병원성은 공시한 C. gloeosporioides와 C. dematium 모두 어린 잎이나 줄기에는 병원성이 없었고 열매에는 강한 병원성을 나타냈다. 성숙과에는 C. dematium Isolate I이 특히 병원성이 강하였고 미숙과에 대하여는 C. dematium Isolate II만이 약하게 나타났으나 10일정도 경과하면 병원성 정도의 구분이 어려웠다.