• 제목/요약/키워드: C.E.R

검색결과 3,082건 처리시간 0.028초

목본식물의 형성층 전기저항에 의한 영구위조점 예측에 관한 연구 (A Study on the Prediction of the Permanent Wilting Point in Woody Plant by Cambial Electrical Resistance)

  • 김민수
    • 한국조경학회지
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    • 제22권4호
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    • pp.75-80
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    • 1995
  • It is important to estimate the possibility of recovery in physiologically damaged woody plant. It is suggested that C.E.R(cambial electrical resistance) might be a useful method to predict the permanent wilting point. D/A and A/D converter can be used to measure the C.E.R and it took only 10-20 msec for a measurement and the values were stable during this study. A computer could be used for the continual measurement of C.E.R. There were very big daily changes of C.E.R. was changed according to the changes of indoor temperature, but the phase was slightly different. It is reasoned that daily changes in C.E.R. is induced by the changes of water potential and cambial thickness. It was difficult to detect the changes of C.E.R. caused by changes in soil moisture under high soil water potential. Under low soil water potential, the changes in soil moisture under high soil water potential. Under low soil water potential, the changes of C.E.R. can be detected. After wilting, C.E.R. is increased very rapidly. When C.E.R. is not decreased by watering, it will be permanent wilting point. But it takes several days to confirm the permanent wilting point. To predict the possibility of recovery from wilting, the values of C.E.R. have no meaning. But the changes of C.E.R. are significant. Therefore we can predict the permant wilting point in woody plant by monitoring the change of C.E.R. by the computer.

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Routley-Meyer Semantics for E-R, Ee-R, Eec-R

  • Yang, Eun-Suk
    • 논리연구
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    • 제6권1호
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    • pp.19-32
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    • 2003
  • In this paper we investigate the relevance logic E-R of the Entailment E without the reductio (R), and its extensions Ee-R, Eec-R: Ee-R is the E-R with the expansion (e) and Eec-R the Ee-R with the chain (c). We give completeness for each E-R, Ee-R, and Eec-R by using Routley-Meyer semantics.

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[r, s, t; f]-COLORING OF GRAPHS

  • Yu, Yong;Liu, Guizhen
    • 대한수학회지
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    • 제48권1호
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    • pp.105-115
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    • 2011
  • Let f be a function which assigns a positive integer f(v) to each vertex v $\in$ V (G), let r, s and t be non-negative integers. An f-coloring of G is an edge-coloring of G such that each vertex v $\in$ V (G) has at most f(v) incident edges colored with the same color. The minimum number of colors needed to f-color G is called the f-chromatic index of G and denoted by ${\chi}'_f$(G). An [r, s, t; f]-coloring of a graph G is a mapping c from V(G) $\bigcup$ E(G) to the color set C = {0, 1, $\ldots$; k - 1} such that |c($v_i$) - c($v_j$ )| $\geq$ r for every two adjacent vertices $v_i$ and $v_j$, |c($e_i$ - c($e_j$)| $\geq$ s and ${\alpha}(v_i)$ $\leq$ f($v_i$) for all $v_i$ $\in$ V (G), ${\alpha}$ $\in$ C where ${\alpha}(v_i)$ denotes the number of ${\alpha}$-edges incident with the vertex $v_i$ and $e_i$, $e_j$ are edges which are incident with $v_i$ but colored with different colors, |c($e_i$)-c($v_j$)| $\geq$ t for all pairs of incident vertices and edges. The minimum k such that G has an [r, s, t; f]-coloring with k colors is defined as the [r, s, t; f]-chromatic number and denoted by ${\chi}_{r,s,t;f}$ (G). In this paper, we present some general bounds for [r, s, t; f]-coloring firstly. After that, we obtain some important properties under the restriction min{r, s, t} = 0 or min{r, s, t} = 1. Finally, we present some problems for further research.

NCFET (negative capacitance FET)에서 잔류분극과 항전계가 문턱전압과 드레인 유도장벽 감소에 미치는 영향 (Impact of Remanent Polarization and Coercive Field on Threshold Voltage and Drain-Induced Barrier Lowering in NCFET (negative capacitance FET))

  • 정학기
    • 한국전기전자재료학회논문지
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    • 제37권1호
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    • pp.48-55
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    • 2024
  • The changes in threshold voltage and DIBL were investigated for changes in remanent polarization Pr and coercive field Ec, which determine the characteristics of the P-E hysteresis curve of ferroelectric in NCFET (negative capacitance FET). The threshold voltage and DIBL (drain-induced barrier lowering) were observed for a junctionless double gate MOSFET using a gate oxide structure of MFMIS (metal-ferroelectric-metal-insulator-semiconductor). To obtain the threshold voltage, series-type potential distribution and second derivative method were used. As a result, it can be seen that the threshold voltage increases when Pr decreases and Ec increases, and the threshold voltage is also maintained constant when the Pr/Ec is constant. However, as the drain voltage increases, the threshold voltage changes significantly according to Pr/Ec, so the DIBL greatly changes for Pr/Ec. In other words, when Pr/Ec=15 pF/cm, DIBL showed a negative value regardless of the channel length under the conditions of ferroelectric thickness of 10 nm and SiO2 thickness of 1 nm. The DIBL value was in the negative or positive range for the channel length when the Pr/Ec is 25 pF/cm or more under the same conditions, so the condition of DIBL=0 could be obtained. As such, the optimal condition to reduce short channel effects can be obtained since the threshold voltage and DIBL can be adjusted according to the device dimension of NCFET and the Pr and Ec of ferroelectric.

흡연인들에서 증가된 혈장지질 농도가 비타민 E 영양상태와 글루타티온 과산화효 활성에 미치는 영향 (The Relation of the Elevated Plasma Lipid Levels to Plasma Vitamin E Status and Activities of Erythrocyte Glutathione Perosicase in Smokers)

  • 윤군애
    • Journal of Nutrition and Health
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    • 제31권8호
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    • pp.1254-1262
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    • 1998
  • This study has done to investigate the relationship between the icreased lipid oncentration caused by smoking and plama levels of vitamin A and vitamin E, antiodative enzyme activity, and lipid peroxidation , in 52 male smokers and 32 non-smokers, Dietary vitamin A and vitamin E intake was imilar in both smokers and non-smokers. Absolute plasma concentrations of vitamin A and vitamin E were not significantly different between two groups, whereas vitamin E/cholesterol ration in plasma was low or in smokers than in that of non-smokers(p<0.05). It was considered that this lowered effect was due to the elevated plasma lipid concentration rather than oxidant stress derived from smoking, in view of the fact that smokers had higher cholesterol (15.2%) adn LDL-C(26.6%) levels than non-smokers. In non-smokers, plasma thiobarbiturin acid reactive substances(TBARS) conrrelated positively with total cholesterol(r=0.63466, p<0.001), LDL-C level(r=0.57166, p<0.01) , and LDL-C/HDL-C ratio(r=0.45926, p<0.05) . Activities of glutathione perosidase(GSH-Px) , superoside dismutase(SOD), and catalse made no difference in both groups. However, it was observed in non-smokers that GSH-Px activity had negative correlations with total cholesterol(r=-0.67293, p<0.001), LDL-C level(r=-0.62878, p<0.001), and LDL-C/HDL-C ratio (r=-0.58824, p<0.01), indicating that there was a dependent relationship between lipid perosidation and plasma lipid level. The smokers also showed negative correlations for GSH-Px activity with total cholesterol (r=-0.29946, p<0.05) and LDL-c level (r=0.45914, p<0.001), and LDL-C/HDL-c ratio(r=-0.35438, p<0.05). It seemed that the lipid that the lipid level elevated by sustaines smoking resulted in reducing vitamin E/cholesterol ratio and proportion of antioxidant to oxidant load, and then GSH-Px activity, with insufficient removal of free radicals(TBARS 2.43$\pm$0.51 and 1.81$\pm$0.15nmol/ml in smokers and non-smokers, respectively). These findings suggest that higher plasma lipid levels may play a more important role in perturbing the antioxidant defense system including vitamin E status and GSH-Px activity, at least in circumstances that increase lipid concentration . In addition, in exposure to free radicals like those in cigarette smoke. In those cases the ratio of vitamin E/lipid in plasma can be a more indicator of vitamin E status than plasma levels of vitamin E alone.

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국내산 복숭아의 품종별 휘발성 향기성분 (Volatile Flavor Components in Various Varieties of Peach(Prunus persica L.) Cultivated in Korea)

  • 박은령;조정옥;김경수
    • 한국식품저장유통학회지
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    • 제6권2호
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    • pp.206-215
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    • 1999
  • 국내에서 생식용 및 가공용으로 널리 재배되고 있는 5종류 품종, 백도ㆍ천도ㆍ유명ㆍ대구보 및 황도의 복숭아의 휘발성 향기성분을 SDE 방법으로 추출하고, 이를 GC와 GC/MS를 사용하여 분리 확인하였다. 복숭아의 품종별 즉 백도, 천도, 유명, 대구보 및 황도에서 83, 85, 70, 74, 66종의 휘발성 향기성분이 각각 동정되었다. 확인된 성분들은 29 알코올, 27 케톤, 18 알데히드, 9 에스터, 5 에테르, 3 유기산. 6 테르펜과 그 유도체 및 26 기타성분으로 구성되었다. 각각의 품종에서 (E)-2-hexenal이 가장 많은 함량을 차지하였으며, 품종별 약간의 차이는 있었지만 ethylacetate, hexanal, o-xylene, (E)-2-hexen-1-ol, benzaldehyde, r-decalactone과 r-dodecalactone 역시 다량 확인되었다. $C_{6}$-C$_{12}$까지의 r-와 $\delta$-lactone류, 특히 이들 lactone류 중에서 다량 검출된 r-decalactone과 r-dodecalactone이 포함된 화합물그룹과 불포화지방산의 과산화물인 $C_{6}$-aldehyde와 $C_{6}$-alcohol이 복숭아의 휘발성 향기성분에 큰 비중을 차지하였다.

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