• Nuclear Engineering and Technology
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• 제42권4호
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• pp.394-413
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• 2010

The object of this paper is to identify the key elements that impact a radiation dose at EAB (Exclusion Area Boundary). This study is based on the AST (Alternative Source Terms) as defined in Regulatory Guide 1.183. The LOCA (Loss of Coolant Accident) and the LRA (Locked Rotor Accident) are selected as limiting cases. A sensitivity analysis of accidental behavior with respect to various parameters during LOCA and LRA at Kori Unit 1 is also undertaken for the following objectives: to determine the limiting parameters, to find the impact trend of the radiation dose, and to find the safety margin between AST and TID (Technical Information Document) methodologies. This work confirms that key parameters are particulate removal rate, decontamination factor, iodine chemical form, gap fraction, partitioning factor, and the impact of isotopes group. Comparing TID with AST, the radiation dose of TID is about 80% greater than that of AST under a LOCA, and about 60% greater than that of AST for the case of a LRA; thus the safety margin is remarkably increased when the AST is used. In this work, the sensitivity analysis results are presented in terms of a sensitivity index called the "NDD (Normalized Dose Difference)", which compares the impact of parameters with that of a reference case. These values are derived by using a combination of the leak rate (primary to secondary), iodine chemical form, gap fraction, partitioning factor, spray removal rate, source term, and other variables.

• 대한의생명과학회지
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• 제27권4호
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• pp.255-263
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• 2021

Human Astrovirus (HuAstV) is an important gastrointestinal pathogen that is frequently reported worldwide. Monitoring of contaminated groundwater has been suggested since HuAstV is transmitted through the fecal-oral route. This study developed a test method based on conventional reverse transcription (RT)-nested polymerase chain reaction (PCR) that involves SL^® non-specific reaction inhibitor for unknown non-specific amplification taking place in the groundwater environment. An optimal method for detecting HuAstV in groundwater sample through analysis and comparison against conventionally reported method was also suggested. The developed method enabled the production of nested PCR amplicon of 630 nt, which is a sufficient length for similarity analysis based on sequencing and genotyping. Amplicons suspected to be HuAstV were amplified in two out of the twenty groundwater samples collected in Korea, presenting 99.77% and 99.73% similarity against HuAstV 1 strain lhar/2011/kor (JN887820.1) in sequencing, respectively. These amplicons were identified as HuAstV 1.

• Bulletin of the Korean Chemical Society
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• 제27권9호
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• pp.1405-1417
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• 2006

The geometrical structures, potential energy surfaces, and energetics for the ligand exchange reactions of tetracoordinated platinum $(PtY_2L_2\;:\;Y,\;L=Cl^-,\;OH^-,\;OH_2,\;NH_3)$ complexes in the ligand-solvent interaction systems were investigated using the ab initio Hartree-Fock (HF) and Density Functional Theory (DFT) methods. The potential energy surfaces for the ligand exchange reactions used for the conversions of $(PtCl_4\;+\;H_2O)^{^\ast_\ast}\;to\;[PtCl_3(H_2O)\;+\;Cl^-]$ and $[Pt(NH_3)_2Cl_2\;+\;H_2O]$$[Pt(NH_3)_2Cl_2\;+\;H_2O]$ to $[Pt(NH_3)_2Cl(H_2O)\;+\;Cl^-] $ were investigated in detail. For these two exchange reactions, the transition states $([PtY_2L_2{\cdot}{\cdot}{\cdot}L^\prime])^{^\ast_\ast} $ correspond to complexes such as $(PtCl_4{\cdot}{\cdot}{\cdot}H_2O)^{^\ast_\ast}$ and $[Pt(NH_3)_2Cl_2{\cdot}{\cdot}{\cdot}H_2O]^{^\ast_\ast}$, respectively. In the transition state, $([PtCl_4{\cdot}{\cdot}{\cdot}H_2O]^{^\ast_\ast}$ and $[Pt(NH_3)_2Cl_2{\cdot}{\cdot}{\cdot}H_2O]]^{^\ast_\ast})$ have a kind of 6-membered $(Pt-Cl{\cdot}{\cdot}{\cdot}HOH{\cdot}{\cdot}{\cdot}Cl)$ and $(Pt-OH{\cdot}{\cdot}{\cdot}Cl{\cdot}{\cdot}{\cdot}HN)$ interactions, respectively, wherein a central Pt(II) metal directly combines with a leaving $Cl^-$ and an entering $H_2O$. Simultaneously, the entering $H_2O$ interacts with a leaving $Cl^-$. No vertical one metal-ligand interactions $([PtY_2L_2{\cdot}{\cdot}{\cdot}L^\prime]) $ are found at the axial positions of the square planar $(PtY_2L_2)$ complexes, which were formed via a vertically associative mechanism leading to $D_{3h}$ or $C_{2v}$-transition state symmetry. The geometrical structure variations, molecular orbital variations (HOMO and LUMO), and relative stabilities for the ligand exchange processes are also examined quantitatively. Schematic diagrams for the dissociation reactions of {PtCl4(H2O)n(n=2,4)} into {$PtCl_3(H_2O)_{(n-2)}\;+\;Cl^-(H_2O)_2$} and the binding energies {$PtCl_4(H_2O)_n$(n = 1-5)} of $PtCl_4$ with water molecules are drawn.

• The Journal of Advanced Prosthodontics
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• 제3권2호
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• pp.57-62
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• 2011

MATERIALS AND METHODS. Ceramics have a long history in fixed prosthodontics for achieving optimal esthetics and various materials have been used to improve ceramic core strength. However, there is a lack of information on how color is affected by fabrication procedure. The purpose of this study was to evaluate the effects of various dentin ceramic thicknesses and repeated firings on the color of zirconium oxide all-ceramic system (LavaTM) fabricated using CAD/CAM technology. MATERIALS AND METHODS. Thirty disc-shaped cores, 12 mm in diameter with a 1 mm thickness were fabricated from zirconium oxide based all ceramic systems ($Lava^{TM}$, 3M ESPE, St Paul, MN, USA) and divided into three groups (n = 10) according to veneering with dentin ceramic thicknesses: as 0.5, 1, or 1.5 mm. Repeated firings (3, 5, 7, or 9) were performed, and the color of the specimens was compared with the color after the initial firing. Color differences among ceramic specimens were measured using a spectrophotometer (VITA Easyshade, VITA Zahnfabrik, Bad $S{\ddot{a}}ckingen$, Germany) and data were expressed in CIELAB system coordinates. A repeated measures ANOVA and Bonferroni post hoc test were used to analyze the data (n = 10, ${\alpha}=.05$). RESULTS. $L^{\ast}a^{\ast}b^{\ast}$ values of the ceramic systems were affected by the number of firings (3, 5, 7, or 9 firings) (P<.001) and ceramic thickness (0.5, 1, or 1.5 mm) (P<.001). Significant interactions were present in $L^{\ast}a^{\ast}b^{\ast}$ values between the number of firings and ceramic thickness (P<.001). An increase in number of firings resulted in significant increase in $L^{\ast}$ values for both 0.5 mm and 1.5 mm thicknesses (P<.01, P=.013); however it decreased for 1 mm thickness (P<.01). The $a^{\ast}$ values increased for 1 mm and 1.5 mm thicknesses (P<.01), while it decreased for 0.5 mm specimens. The $b^{\ast}$ values increased significantly for all thicknesses (P<.01, P=.022). As the dentin ceramic thickness increased, significant reductions in $L^{\ast}$ values (P<.01) were recorded. There were significant increases in both $a^{\ast}$ and $b^{\ast}$ values (P<.01) as the dentin ceramic thickness increased. CONCLUSION. The number of firings and dentin ceramic thickness have a definite effect on the final color of all ceramic system tested. The mean ${\Delta}E$ value increased as the dentin ceramic thicknesses increased for zirconium-oxide based all ceramic specimens tested. However, the mean ${\Delta}E$ values were less than 3.7${\Delta}E$ units which is rated as a match in the oral environment.

• Journal of Preventive Medicine and Public Health
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• 제21권2호
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• pp.329-339
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• 1988

간기능에 대한 음주와 흡연의 영향을 보기 위해서 1986년 12월 25일부터 1987년 4월 30일까지 약 4개월에 걸쳐 대구의료원을 찾은 채용신체검사 수검자들 중에서 AST 및 ALT 활성도검사, 간염 항원 항체검사, 간디스토마 피내반응검사를 실시한 900명의 검사성적과 설문지를 분석하여 AST 및 ALT 이상자율을 비교검토 하였다. AST 및 ALT 이상자율을 유해인자 수별로 보면 간기능 유해요인수의 증가에 따라 이상자율이 높았다. 특히 HBs-Ag, 음주 및 흡연의 상호복합작용에 있어서 AST 및 ALT 이상자율이 높았다. 단일 음주군, 흡연군에 대한 연령에 따른 AST 및 ALT 이상자율은 유의한 상관성이 없었고, 30대에서 다소 이상자율이 높게 나타났다. 단일 음주군의 AST 및 ALT 이상자율은 음주기간이 길 수록, 음주량이 많을 수록, 음주빈도가 잦을 수록 증가하는 경향을 보였다. 다만, 막걸리와 소량의 맥주 음주자에게서는 이상자가 없었다. 단일 흡연군의 전이효소 활성치 이상자율도 흡연기간이 길 수록, 일일 흡연량이 많을 수록 증가하는 경향이었다. 음주 및 흡연군에 대한 AST 및 ALT의 이상자율은 변량상관행렬에서 음주와 흡연기간이 길수록, 흡연량 및 나이가 많을수록 높았으며, 다중회귀분석결과는 음주기간, 음주량 및 음주빈도와는 유의한 상관성을 보였으나, 흡연량, 흡연기간과는 유의한 상관성이 없었다. AST 및 ALT의 이상율에 대한 이들 선택된 변수들은 13.0%의 설명력을 가지고 있다.

• 한국정보과학회논문지:시스템및이론
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• 제36권6호
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• pp.502-510
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• 2009

Multiprecision Squaring은 공개키 알고리즘을 구성하는 연산 중에서 가장 중요한 연산 중 하나이다. 본 논문에서는 기존의 Multiprecision Squaring 알고리즘을 개선하여 연산 양을 줄임으로 성능을 항상시키는 Squaring 기법들을 제시하고 구현하였다. Scott이[1]에서 제안한 Carry-Catcher Hybrid 곱셈 알고리즘은 Gura가 제안한 Hybrid 곱셈 알고리즘[2]을 계승 발전시킨 것으로 MRACL 라이브러리에 구현되어 있으며, Carry-Catcher Hybrid 방법 사용한 Multiprecision Squaring 알고리즘도 MIRACL에 함께 구현되어 있다. 본 논문에서 이 Carry-Catcher Hybrid Squaring 알고리즘을 발전시켜 보다 효율적인 Squaring 알고리즘인 Lazy Doubling Squaring 알고리즘을 제안하고 구현하였으며, atmega128상에서 성능테스터를 수행하여 Carry-Catcher Hybrid Squaring 알고리즘과 비교하여 더 효율적인 알고리즘임을 보였다. 표준 Squaring 알고리즘이 $S_{ij}\;=\;x_i\;{\ast}\;x_j\;=\;S_{ij}$인 사실을 기반으로 곱셈의 횟수를 절반 가까이 줄인 알고리즘이라면 본 논문에서 제시한 Lazy Doubling Squaring 알고리즘은 $a_0\;{\ast}\;2\;+\;a_1\;{\ast}\;2\;+\;...\;+\;a_{n-1}\;{\ast}\;2\;+\;a_n\;{\ast}\;2\;=\;(a_0\;+\;a_1\;+\;...\;+\;a_{n-1}\;+\;a_n)\;{\ast}\;2$ 라는 사실을 기반으로 하여 doubling 연산 횟수를 획기적으로 줄인 알고리즘으로, MIRACL에 구현되어 있는 Multiprecision Squaring 알고리즘 보다 atmega128상에서 약 25% 정도의 빠른 결과를 얻을 수 있었으며, 저자가 아는 바로는 현재까지 나온 어떤 방법보다 빠르다.

• 한국환경농학회지
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• 제19권1호
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• pp.67-71
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• 2000

재배년수와 토성이 도라지 생육 및 수량에 미치는 영향을 연구한 결과는 다음과 같다. 재배년수가 2년에서 8년까지 양질사토에서 시험한 결과 재배년수와 1근중은 $Y=17.246X+0.95(R^2=0.948^{{\ast}{\ast}{\ast}})$, 발병율은 $Y=12.01X-5.74(R^2=0.946^{{\ast}{\ast}{\ast}})$로서 고도의 유의성이 있었다. 재배년수가 길수록 뿌리의 T-N, $P_2O_5$, MgO 함량은 감소되었고 장해근은 정상근에 비해 T-N, $P_2O_5$, $K_2O$ 함량이 높았다. 도라지 2년생을 양질사토, 사양토, 미사질양토와 식양토에서 시험한 결과 시험후 pH는 미사질양토가 6.4였으며 다른 토성에서는 $5.7{\sim}5.8$의 수치를 나타내었고 $P_2O_5$ 및 Fe 함량은 미사질양토에서 높았다. 도라지 생육상황은 미사질양토에서 지상중 10.38g, 근경 1.34cm, 근장 16.8cm, 초장 57.9cm로 양호하여 1근중이 5.46g으로 가장 높았다.

• Nutritional Sciences
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• 제9권1호
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• pp.20-28
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• 2006

Aryl sulfotransferase (AST) IV is a liver enzyme involved in detoxication and has been shown to be susceptible to down regulation by a number of hepatotoxic xenobiotics. Studies presented here to investigate the ability of biological and non-biological divalent metal cations on AST IV activity showed that AST IV was strongly inhibited following in vitro or in vivo exposure to. Zn ( II ), Co ( II ) or Cd ( II ). It was found that $0.025\sim$2.5 uM of these metal ions were sufficient to cause $50\%$ of inhibition in vitro in purified AST IV and $0.25\sim$25 uM of these metal ions in liver cytosolic fractions. For the in vivo study, 1,000 mg Cu ( II )/kg, 2,000 mg Zn ( II )/kg or 250 mg Cd( II )/kg was added to individual diets and administered to three (3) group; of mts over a 7 week period The Co ( II )-supplemented diet produced no apparent change in rat growth rate and resulted in 30-fold increase in liver cytotolic Cu ( II ) levels, suggesting that elevated levels of Cu ( II ) ion in the liver were responsible for the loss of AST IV activity. In contrast, the Zn ( II )-supplemented diet caused a decrease in rat growth rates and resulted in zero increase in liver Zn ( II ) levels, which suggested an indirect inhibition mechanism was caused by Zn ( II ) in the liver. Rats were fed the Cd-supplemented diet also displayed a decrease in growth rate with little or no change in liver Cu ( II ) or Zn ( II ) levels. When the liver cytosols of mts from the metal ion diets were immunochemically analyzed for the AST IV and albumin contents, no significant changes were observed in albumin levels. However, AST IV contents in the cytosols of mts fed the Zn ( II )-supplemented diets showed a slight decrease in amount These results showed that AST IV activity in vitro and in vivo can be inhibited by Co ( II ), Zn ( II ), and Cd ( II ) by apparently different mechanisms. The immediate response to a Zn injection showed a decrease in AST IV activity but not in the AST IV content in liver cytosol. These mechanisms appeared to involve direct actions of the metal ion on AST IV activity and indirect actions affecting AST IV amount.

• 대한임상검사과학회지
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• 제55권1호
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• pp.9-15
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• 2023

본 연구의 목적은 당뇨 검사결과와 간기능검사와의 관계연구이다. 간성당뇨는 제2형 당뇨와는 다르게 간기능 이상으로 기인하는 것이다. 본 연구에서 간기능 검사의 주요 효소검사인 아스파르트산 아미노전이효소(aspartate aminotransferase, AST), 알라닌 아미노전이효소(alanine aminotransferase, ALT) 그리고 AST/ALT ratio (De Ritis ratio)와 당뇨관련 검사와의 관계를 주로 확인하였다. 연구 결과 AST와 글루코스(glucose) (r=0.14, P<0.01); ALT 및 글루코스(r=0.21, P<0.01); AST 및 당화혈색소(HbAlc) (r=0.15, P<0.01); ALT와 HbAlc (r=0.20, P<0.01), 모든 변수는 양의 상관관계를 나타났으며, De Ritis ratio는 글루코스 (r=-0.20, P<0.01)와 당화혈색소 (r=-0.14, P<0.01)와 음의 상관관계를 보였다. AST와 ALT 그리고 De Ritis ratio 를 독립변수로 하고 글루코스 (R²=0.05) 와 HbA1c (R²=0.04) 를 종속변수로 하여 회귀분석한 결과 독립변수는 종속변수에 통계적으로 유의하게 영향을 나타내는 것으로 나타났다. AST는 ALT 보다 혈당과 당화혈색소에서 상관관계가 낮게 나타났으며, ALT가 증가하는 것은 즉, De Ritis ratio 감소의 원인이 된다. 따라서, De Ritis ratio는 당뇨관련 검사와의 관계에서 의미가 있는 것으로 볼 수 있다.

• 대한수학회보
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• 제42권1호
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• pp.169-177
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• 2005

A Hilbert Space operator T is of class Q if $T^2{\ast}T^2-2T{\ast}T + I$ is nonnegative. Every paranormal operator is of class Q, but class-Q operators are not necessarily normaloid. It is shown that if a class-Q contraction T has no nontrivial invariant subspace, then it is a proper contraction. Moreover, the nonnegative operator Q = $T^2{\ast}T^2-2T{\ast}T + I$ also is a proper contraction.