• Journal of the Korean Society of Tobacco Science
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• v.31 no.1
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• pp.51-57
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• 2009

• Proceedings of the Korean Nuclear Society Conference
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• 1995.05b
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• pp.1027-1032
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• 1995

To develop operation scenarios of KT-2 tokamak, 3 operation modes(OH, high ${\beta}$ and high bootstrap) deduced from zero dimensional steady-state power balance are examined with TSC(Tokamak Simulation Code) time-dependent transport .ode. Plasma profiles are evaluated self consistently during simulations and plasma shapes are maintained by feedback control on PF coil currents. Simulations show operation modes which are typical of KT-2 expected discharges are compatible with the KT-2 PF system design specifications[1].

• Journal of applied mathematics & informatics
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• v.14 no.1_2
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• pp.39-49
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• 2004

Let G be a simple graph and let $\={G}$ denotes its complement. We say that G is integral if its spectrum consists entirely of integers. If $\overline{aK_{a}\;{\bigcup}\;{\beta}K_{b}}$ is integral we show that it belongs to the class of integral graphs $[\frac{kt}{\tau}\;{x_0}\;+\;\frac{mt}{\tau}\;z}\;K_{(t+{\ell}n)+{\ell}m}\;\bigcup\;[\frac{kt}{\tau}\;{y_0}\;+\;\frac{(t\;+\;{\ell}n)k\;+\;{\ell}m}{\tau}\;z]n\;K_{em)$, where (i) t, k, $\ell$, m, $n\;\in\;\mathbb{N}$ such that (m, n) = 1, (n,t) = 1 and ($\ell,\;t$) = 1 ; (ii) $\tau\;=\;((t\;+\;{\ell}n)k\;+\;{\ell}m,\;mt)$ such that $\tau\;$\mid$kt$; (iii) ($x_0,\;y_0$) is a particular solution of the linear Diophantine equation $((t\;+\;{\ell}n)k\;+\;{\ell}m)x\;-\;(mt)y\;=\;\tau\;and\;(iv)\;z\;{\geq}\;{z_0}$ where $z_{0}$ is the least integer such that $(\frac{kt}{\tau}\;{x_0}\;+\;\frac{mt}{\tau}\;{z_0})\;\geq\;1\;and\;(\frac{kt}{\tau}\;{y_0}\;+\;\frac{(t+{\ell}n)k+{\ell}m}{\tau}\;{z_0})\;\geq\;1$.

• ETRI Journal
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• v.14 no.4
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• pp.35-42
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• 1992

본 고에서는 X.25 동기 프로토콜(1)을 이용한 KT-MAiL 서비스의 확장 네트워킹의 실현에 대해 기술하고, 많은 사용자에게 서비스를 제공하기 위한 KT-MAiL 호스트 시스팀과의 인터페이스 및 실현후의 패킷 전송 성능에 대해 기술하고자 한다.

• Digital Contents
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• no.10 s.149
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• pp.24-25
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• 2005

남중수 KT 사장은 지난달 7일 서울 프레스센터에서 취임 후 첫 기자간담회에서 민영 2기 KT의경영기조로내세운‘ 원더(Wonder) 경영’을전면에내세우며특유의경영론을밝혔 다. 남사장은실제로이날‘ PCS 재판매시장점유율6.2% 동결’, ‘ 국내1위영화사인싸 이더스지분출자를통한디지털콘텐츠시장진출’등획기적인경영목표들을발표했다.

• Journal of the Korean Society of Tobacco Science
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• v.36 no.1
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• pp.20-25
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• 2014

As part of a balanced testing battery, subchronic inhalation studies on rats are performed to ensure that proposed cigarette modifications do not increase the toxicity of smoke and to demonstrate any instances where a modification may actually contribute to harm reduction. For subchronic inhalation studies with aerosols, the OECD suggests an exposure regimen of 6 hours/day (OECD Guideline 413, 1981), but alternative regimens have also been published: 1 hour/day and $2{\times}1$ hour/day. The aim of this study was to validate a rodent nose-only exposure system for the assessment of inhalation toxicity of cigarette smoke. In this study, cigarette smoke exposure system is consisted of cigarette smoke generator, smoke concentration adjusting system, and 20-port nose-only exposure system. Male SD rats were exposed for 35 days ($2{\times}1$ hour/day) to 3R4F Reference cigarette smoke and analysed major monitoring items of OECD Gudeline 413. WTPM, was measured in the test atmosphere, respiratory function (Buxco Biosystems) during exposure, postexposure urinary exposure biomarkers and alveolar neutrophiles in BAL fluid (Day 35) were evaluated. Validation demonstrated steady WTPM ($257{\pm}20ug/L$, $502{\pm}27ug/L$) and spatial uniformity (<10%). Nose port temperature ($22{\sim}26^{\circ}C$ and RH (45~75%) were acceptable over 35 days. Reductions in respiratory rate and minute volume and increase in the neutrophiles in BALF and the urinary exposure biomarkers were observed cigarette smoke dose dependently. This validation and 35-day inhalation study has shown that the rodent nose-only exposure system may be useful in the inhalation toxicity assessment of cigarette smoke.

• Journal of the Korean Society of Tobacco Science
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• v.32 no.1
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• pp.19-27
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• 2010

The aim of this study is to compare the sensitivity of both two NCI-H292 and A549 cell types to acute inflammatory responses induced by cigarette smoke. For this, we treated two kinds of smoke fractions derived from 2R4F reference cigarettes: total particulate matter(TPM) collected onto a Cambridge filter pad and gas/vapor phase(GVP) prepared by bubbling through in buffer solution. When we measured cellular cytotoxicity by neutral red uptake assay after treatment for 24 hours, TPM and GVP induced cytotoxic effect in a dose-dependent manner in the range of 10-$100{\mu}g$/mL and 60-$300 {\mu}g$/mL., respectively, in both cell types without any cellular difference. Additionally, when we examined acute inflammatory responses by analyzing cytokines secreted into culture media including tumor necrosis factor-$\alpha$ (TNF-$\alpha$), interleukin-8(IL-8), and transforming growth factor-$\alpha$(TGF-$\alpha$) as well as matrix metalloproteinase-1(MMP-1), the treatment with smoke fractions increased those marker proteins in a dose-dependent manner in NCI-H292. Meanwhile, in A549 cells only MMP-1 was observed to be increased in a dose-dependent fashion. Collectively, our data indicate that NCI-H292 cell type is more sensitive to cigarette smoke-induced inflammatory response than A549 cells. This suggests that NCI-H292 could be useful as an in vitro evaluation tool to assess harmful effects of cigarette smoke.

• Korean Journal of Transplantation
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• v.31 no.4
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• pp.200-206
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• 2017

Background: Risk factors for bone avascular necrosis (AVN), a common late complication after kidney transplantation (KT), are not well known. Methods: Patients that underwent living-donor KT at Asan Medical Center between January 2009 and July 2016 were included in this retrospective study to determine the incidence and risk factors for AVN after KT. Results: Among 1,570 patients that underwent living-donor KT, 33 (2.1%) developed AVN during a mean follow-up of 49.8±25.0 months. Additionally, AVN was diagnosed at a mean of 13.9±6.6 months after KT. The mean cumulative corticosteroid dose during the last follow-up in patients without AVN (9,108±3,400 mg) was higher than that that in patients with AVN (4,483±1,114 mg) until AVN development (P<0.01). More patients among those with AVN (n=4, 12.1%) underwent steroid pulse treatment because of biopsy-proven rejections during the first 6 months after KT than patients without AVN (n=68, 4.4%; P=0.04). Female (hazard ratio [HR], 2.29; P=0.04) and steroid pulse treatment during the first 6 months (HR, 2.31; P=0.02) were significant AVN risk factors as revealed by the Cox proportional multivariate analysis. However, no significant differences in rejection-free graft survival rates were observed between the two groups (P=0.67). Conclusions: Steroid pulse treatment within 6 months of KT and being female were independent risk factors for AVN development.

• Korean Journal of Remote Sensing
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• v.17 no.1
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• pp.85-97
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• 2001

The KT(Kauth-Thomas) and IHS(Intensity-Hue-Saturation) transformation techniques were introduced and compared to investigate fire-scarred areas with single post-fire Landsat 7 ETM+ image. This study consists of two parts. First, using only geometrically corrected imagery, it was examined whether or not the different level of fire-damaged areas could be detected by simple slicing method within the image enhanced by the IHS transform. As a result, since the spectral distribution of each class on each IHS component was overlaid, the simple slicing method did not seem appropriate for the delineation of the areas of the different level of fire severity. Second, the image rectified by both radiometrically and topographically was enhanced by the KT transformation and the IHS transformation, respectively. Then, the images were classified by the maximum likelihood method. The cross-validation was performed for the compensation of relatively small set of ground truth data. The results showed that KT transformation produced better accuracy than IHS transformation. In addition, the KT feature spaces and the spectral distribution of IHS components were analyzed on the graph. This study has shown that, as for the detection of the different level of fire severity, the KT transformation reflects the ground physical conditions better than the IHS transformation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.225-229
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• 2003

The exact performance simulation of propulsion system is a key element in the prediction of the aircraft performance. The specification performance analysis using the installed loss of KT-1 showed a large difference with the engine performance measured during the flight tests. This indicates that a method to estimate the more exact performance is needed. The study on the performance simulation with performance map correction along the engine operating line shows the good consistent results through all the flight conditions and engine conditions. The correction factors of the map were resulted from the comparative analysis between the flight test and the simulation of installed engine performance.