• Journal of Elementary Mathematics Education in Korea
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• v.21 no.2
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• pp.365-389
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• 2017

This study aims to analyze elementary gifted students' inquiries on combinatoric tasks. In particular, we designed circular permutation tasks and analyzed students' inquiries on these tasks. We especially analyzed students' expressions, counting processes, and their construction of set of outcomes. The findings showed that the students utilized analogy to resolve given tasks, and they had difficulties in categorizing and re-categorizing possible outcomes of given tasks. Their improper use of analogy also caused difficulties in resolving circular permutation tasks.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2002.10a
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• pp.1-15
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• 2002

동복터널의 현장지질은 편마암과 석탄층(Coal Beds)이 협재된 암질이 매우 불량한 편암으로 구성되어 있으며, 설계 시에는 석탄층의 발달이 확인되지 않아 그 영향을 충분히 고려되지 않았다. 석탄층(두께 2~8m)은 편암의 Rock Cleavage와 같은 방향과 45~55도의 경사를 가지며 pinch out and swelling 형태로 발달이 불규칙하다. 하행선굴착 중 약 290m구간에 걸쳐 석탄층이 나타났으며, 90m 구간은 천단 및 측벽부에서 집중 발달되어 쳐대일변위가 20mm이상인 지점이 발생하는 등 상반굴착 시 111.2mm의 수평방향 내공변위가, 하반굴착 시에는 최대 127.8mm의 내공변위가 발생하였고 하반관통이후 수렴되었다. 내공변위 과다발생에 대한 대책으로 지보타입을 하향 조정하였고 측벽부는 하향 록볼트를 포함한 추가록볼트 보강을 실시하였다. 한편 터널 바닥부의 석탄층은 도로포장 후 침하문제가 예상되어 인버트를 기존 강지보공과 H-beam으로 연결.폐합한 후 콘크리트로 치환(140m구간)하여 추가변위를 최소화하였으며 무근콘크리트로 설계된 라이닝은 철근콘크리트 라이닝으로 변경 시공하였다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1521_1522
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• 2009

Chemotaxis is the directed movement of cells in gradients of signaling molecules, an essential biological process that underlies morhpogenesis during development, and the recruitment of immune cells to sites of infection. Especially, bacterial chemotaxis has utilized as an important prelude to study metabolism, prey-predator relationship, symbiosis, other ecological interactions in microbial communities. Recently, novel analytical formats integrated with microfluidics were introduced to investigate the chemotaxis of the cells with the precise control of chemical gradient and small volume of cells. In this study, we present a method to detect bacterial chemotaxis by direct fluidic contacting. The developed fluidic-handling method is driven by capillary force, hydrophobic barrier and a cohesion force between fluids. We have investigated the chemotactic response of E Coli. and Pseudomonas aeruginosa to three kinds of chemoeffectors such as HEPES buffer, peptone and chloroform.

• Journal of the Korean Society for information Management
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• v.14 no.1
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• pp.207-222
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• 1997

This study is aimed at design and implementation of data format for non-book materials in the field of library user interface. The ba-sic data elements were complied with KORMARC and some amend-ments with detailed expansions were applied for development of the use of at libraries. The data formats of various types of media such as books, audio materials, image data, pamphlets, posters which stored in art library were designed respectively through the use of Graphical User Interface.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.3 no.1
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• pp.49-65
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• 1997

In order to investigate the effects of Sojeokbaekchoolsan on the various immune responses, the chemotactic and adherent ability of macrophages were studied in vivo and in vitro. The results obtained were follows: 1. The administration of Sojeokbaekchoolsan enhanced significantly the Chemotactic activity of macrophages and neutrophils. 2. The administration of Sojeokbaekchoolsan enhanced significantly the adherent activity of macrophages and neutrophils. From above findings, it is suggested that Sojeokbaekchoolsan seem to produce the increase of immune response such as the chemotactic activity and adherent activity of macrophage. According to the above results, it could be suggested that Jukyeopseokgo-tanggagambang extract has indirect autitumor effects by strengthening the effects of MMC on tumor cells.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.87-90
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• 2007

셰일층으로 구성된 암반사변에서 층리면을 따라 대규모 평면파괴가 사연 중앙부에서 발생하였다. 현장조사시 파괴사면 주변은 지하수 누수 흔적과 점토층의 충전물이 존재하였으며, 파괴원인을 검토한 결과 층리면을 따라 형성된 점토 충전물의 낮은 전단강도와 강우시 인장균열내 형성된 수압에 의해 붕괴가 발생한 것으로 나타났다. 그리고 충전된 절리면의 전단강도 특성을 규명하기 위해서 모래, 점토의 인위적인 충전물을 이용하여 충전재 두께비에 따른 전단강도 특성을 고찰하였다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.325-328
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• 2009

Many types of new Korean Firearms were developed during the reign of King Se Jong(1418~1450). After the Chong-Tong-Deung-Rok(1448), the Ju-hwa was renamed as the Sin-Gi-Jeon. There was four kinds of rocket propelled arrows : So(small), Chung(medium), Dae(large) and San-hwa(multiple bomblets)-Sin-Gi-Jeon. Dae-Sin-Gi-Jeon is known to be the best and the largest of any rocket propelled arrows in the 15th century. This paper describes its flight test result.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.1018-1022
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• 2008

Testicular adrenal rest tumors are a well-known complication in male patients with congenital adrenal hyperplasia. Corticosteroid suppressive therapy usually results in the regression of these tumors. We describe a patient with 21-hydroxylase deficiency who developed bilateral testicular masses. Despite steroid suppressive therapy, the tumors did not regress and hormonal control was poor. Consequently, bilateral partial orchiectomies were performed.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.711-712
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• 2002

A numerical study of a hemodynamical model for the tumor angiogenesis is carried out. The tumor angiogenesis process is comprised of a sequence of events; secretion of tumor angiogenesis factor(TAF) from the solid tumor, degradation of the basement membrane of nearby blood vessels, migration and proliferation of the endothelial cells. The model takes into account the effect of TAF concentration and endothelial cell density, and their conservation equations are represented as a set of one-dimensional initial boundary value problems. These equations are discretized by using a finite difference method in which the second order schemes both in time and in space are used. The effects of the parameters contained in the model are Investigated extensively through the numerical simulation of the discretized model. The result for the typical case compares very well with the known result.

• Korean Journal of Pharmacognosy
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• v.34 no.4 s.135
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• pp.314-317
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• 2003

Inhibitory effects of the whole extract and isolated compounds from the leaves of Vaccinium koreanum (Ericaceae) on rat lens aldose reductase (RLAR) and on platelet aggregation were investigated for the prevention or the treatment of chronic diabetic complications. Arbutin, isolated from n-butanol fraction of methanol extract, exhibited a potent inhibitory effects on rat platelet aggregation induced by ADP $(IC_{50}=0.12\;{\mu}M)$ and collagen $(IC_{50}=0.039\;{\mu}M)$ and showed same inhibitory activities with positive control, tetramethylene glutaric acid, on RLAR.