• The Pure and Applied Mathematics
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• v.11 no.2
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• pp.139-147
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• 2004

Let {<$\mathds{X}_t$} be an m-dimensional linear process of the form $\mathbb{X}_t\;=\sumA,\mathbb{Z}_{t-j}$ where {$\mathbb{Z}_t$} is a sequence of stationary m-dimensional negatively associated random vectors with $\mathbb{EZ}_t$ = $\mathbb{O}$ and $\mathbb{E}\parallel\mathbb{Z}_t\parallel^2$ < $\infty$. In this paper we prove the central limit theorems for multivariate linear processes generated by negatively associated random vectors.

• Archives of Pharmacal Research
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• v.25 no.4
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• pp.438-440
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• 2002

A new unsaturated hydroxy fatty acid was isolated from the leaves of Cucurbita moschata through repeated silica gel column chromatography and chemical methods. The structure of the new fatty acid was determined as 13-hydroxy-9, 11, 15-octadecatrienoic acid on the basis of several spectral data including 2D-NMR. The stererostructures of double bonds were determined to be 9Z, 11 E and 15E by coupling patterns of related proton signals in the $^1H-NMR$ and NOESY experiments.

• Korean Journal of Medicinal Crop Science
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• v.19 no.1
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• pp.1-8
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• 2011

Biological characteristics of 5 Zanthoxylum schinifolium (Zs) fruits such as Z1 (early August), Z2 (middle August), Z3 (middle September), Z4 (early October) and Z5 (middle October) according to harvesting time were evaluated. As fruits ripened, average weight of Zs increased from 4.8mg (Z1) to 50.7mg (Z5), while moisture contents decreased from 74.6% (Z1) to 55.2% (Z5). Crude fat contents of the fruits during ripening increased from 1% (Z1) to 10.6% (Z5). The major fatty acids in Zs were palmitic (C16:0), palmitoleic (C16:1), oleic (C18:1), and linoleic (C18:2) acids. Linoleic acid (C18:2) was a main fatty acid in Z1 and Z2, whereas oleic acid (C18:1) was found as a main one in the other Zs. The ratio of unsaturated fatty acid to total fatty acids increased from 60% (Z1) to 80% (Z3~Z5) during ripening. Among ripening stages, Z4 had the highest contents of total fatty acids ($3,355{\mu}g/g$) and total unsaturated fatty acids ($2,753{\mu}g/g$). Forty six volatile compounds in Zs were also identified. The major volatile compounds were ${\alpha}-pinene$, ${\beta}-myrcene$, ${\beta}-ocimene$, 2-nonanone, estragole, 2-undecanone, and ${\beta}-caryophyllene$. Major volatile components of Z1 were ${\beta}-ocimene$ (20.8 peak area %) and ${\alpha}-pinene$ (9.7 peak area %). In Z2, estragole (30.1 peak area %) was a main volatile compound, but the contents of ${\alpha}-pinene$ (0.4 peak area %), ${\beta}-myrcene$ (0.3 peak area %), and ${\beta}-ocimene$ (0.6 peak area %) were lower than those in Z1. Especially, estragole used as perfumes and as a food additive for flavor was drastically increased to 91.2 (Z3) and 92% (Z4) as fruits ripened.

• Food Science and Biotechnology
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• v.14 no.1
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• pp.68-72
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• 2005

Moisture sorption characteristics of edible composite films were determined and compared against moisture barrier properties. Edible composite films were Z1 (zein film with polyethylene glycol(PEG) and glycerol), Z2 (zein film with oleic acid), ZA1 (zein-coated high amylose corn starch film with PEG and glycerol), and ZA2 (zein-coated high amylose corn starch film with oleic acid). Z2 film showed the lowest equilibrium moisture content (EMC), monolayer value ($W_m$), water vapor permeability (WVP), and water solubility (WS). Surface structure of Z2 was relatively denser and finer than that of other edible films. GAB $W_m$ and C values decreased, while K values increased with increasing temperature. Correlation coefficients of WS:EMC and WVP:EMC at Aw 0.75 were higher than those of WS: $W_m$ and WVP: $W_m$, respectively. EMC values at Aw 0.75 appeared useful for evaluating or predicting moisture barrier properties of edible films.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.468-472
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• 2005

In this paper, the static and dynamic stiffness of the air bearing stage for micro-micro machine tool are examined experimentally. For stiffness and precision concerns, air bearing stages are adapted for 3-axis micro-milling machine which is size of $200x200\;mm^2$. The air bearings in the stage are preloaded by permanent magnets to achieve desired bearing clearance and stiffness for vertical direction. As the stiffness of the air bearing is primary interests, static stiffness test were performed on XY stage in Z direction and Z column in Y direction. Dynamic test were performed on XY stage and Z column, respectively. Both static and dynamic tests were performed in different air pressure conditions. The vertical stiffness of XY stage is about 9 N/ pm where Y stiffness of Z column is much smaller as $1\;N/{\mu}m$ because of the large moment generated by Y force on the column.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2003.04a
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• pp.46-46
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• 2003

Three phospholiplds (4 6) and three aromatic amines (1 3) were obtained from the methanol extract of Bombycis corpus. Based on spectral data, their structures have been elucidated as nicotiamide(1), cytidine(2), adenine(3), 1-O-(9Z-octadecenoyl)-2-O-(8Z, llZ-octadecadienoyl)-sn-glycero-3-phosphorylcholine(4), 1,2-di-O-hexadecanoly-sn-glycero-3-phosphorylcholine(5) and 1,2-di-O-9Z-octadecenoly-sn-glycero-3-phosphorylcholine(6). (omitted)

• Journal of the Korean Wood Science and Technology
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• v.47 no.6
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• pp.700-708
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• 2019

To verify the possibility of using resistograph to estimate the age of big old living trees, we selected three Zelkova serrata and seven Pinus densiflora in Goesan. The mean diameters at breast height of Z. serrata and P. densiflora were 102 (92-116) cm and 80 (65-110) cm, respectively. The heights measured from the ground using a resistograph ranged at 1.2-4.3 m and 0.6-1.1 m for Z. serrata and P. Densiflora, respectively. The most appropriate needle speed to determine tree-ring boundaries for measuring ring width was 1500 r/min for both tree species. Alternatively, the suitable feed speeds for Z. serrata and P. densiflora were 50 cm/min and 150 cm/min, respectively. From the measured data, the mean numbers of tree rings of Z. serrata and P. densiflora were 57 (43-68) and 104 (93-124), respectively, and the mean tree-ring widths were 4.27 mm (3.18-5.09 mm) and 2.93 mm (2.32-3.34 mm), respectively. A comparison between the time series of tree-ring widths by resistograph and that from the local master chronologies tallied for the heartwood part. Finally, this study showed that resistograph can be used to estimate tree ages when a local master chronology is available.

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.183-186
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• 1995

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.510-513
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• 1988

This paper describes an effective trunk loop signal processing method and analyzes execution time of program in the DTCP(Digital Trunk Circuit Processor) in the TDX-1A digital switching system. To predict a maximum trunk capacity, also analyzes to Z80A system clock(4Mbit/s, 2.5Mbit/s) and scanning period(8mS,5mS) respectively.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.11
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• pp.20-22
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• 1993