• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.74.1-74
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• 2001

• Korean Journal of Environment and Ecology
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• v.9 no.2
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• pp.166-181
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• 1996

This study was conducted to investigate the community structure of old-growth forest and vegetation-environment relationships in the Sangwonsa-Bironbong area, Odaesan National Park. TWINSPAN and DCA were used to identify and describe the community types for 45 sample sites. The results of DCA ordination showed that soil pH, soil organic matters and soil moisture played a role in determining community types in the study area. Community types of the study area were role in determining community types in the study area. Community types of the study area were classified into 6 groups by TWINSPAN; Abies holophylla-Carpinus koraiensis community. Each community types were significantly different in soil pH and soil organic matters. And each community types can be explained by geographical features.

• The Korean Journal of Ecology
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• v.12 no.4
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• pp.209-218
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• 1989

In order to elucidate the relationship among the several forest types in the green-sbelt nearby Seoul, the vascular plant species data collected preferentially from 52 stands were subjected to DCA (detrended correspondence analysis). Eight types of forests were arranged on the I/II plane fo DCA stand ordination, Quercus mongolica, Alnus hirsuta, Populus alba $\times$ glandulosa, Robinia pseudo-acacia, Pinus densiflora, Pinus koraiensis, Larix leptolepis and pinus rigida forest. Correlation analysis between the stand scores of DCA and environmental factors revealed that the axis I of DCA stand ordination implied the gradient of altitude, organic matter, total nitrogen and depth of A horizon. The axis II implied the gradient of total nitrogen and soluble phosphorus. The results of PCA (principal components analysis) by environmental data were in good agreement with that of DCA by floristic data. The recruitments of Quercus spp. Occurred in all kinds of forest types in the green-belt and their recruitments were closely related with altitutde: Quercus dentata in the foot. Quercus serrata in the midslope and Quercus mongolica in the uperslope of the mountain.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.12a
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• pp.107-108
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• 2006

High $J_c$ $YBa_2Cu_3O_x$, superconducting films were fabricated by MOD method using fluorine-free dichloroacetic acid(DCA) as chelating solvent for preparing precursor solution. DCA-MOD precursor solution was coated on a single crystal (001) $LaAlO_3$(LAO) substrate by a dip coating method with a speed of 25 mm/min. Coated films were calcined at lower temperature up to $500^{\circ}C$ and Conversion heat treatment was performed at various temperatures of $780{\sim}810^{\circ}C$. SEM observations showed that films have very dense microstructures for the films prepared at the temperature higher than $800^{\circ}C$ regardless of diluting solvent; methanol or 2-methoxyethanol. A High critical current density ($J_c$) of 1.28 $MA/cm^2$ (@77 K and self-field) was obtained for the YBCO film prepared using 2-methoxyethanol as a solvent.

• Journal of Photoscience
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• v.5 no.1
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• pp.23-26
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• 1998

Irradiation of diphenylbutadiyne (DPB) in methanol with 9,10-dicyanoanthracene (DCA) yields four methanol adducts, two more than the products obtained in the absence of DCA. Laser flash photolysis studies indicate the reaction to proceed through a photoinduced electron transfer mechanism involving DPB cation radical and DCA anion radical.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.10
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• pp.786-791
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• 2002

An experimental study on the behavior of the water hold-up by spraying of a fin-and-tube heat exchanger with regard to the surface characteristics, i.e., contact angles, was conducted. The dynamic contact angles (DCA) were measured, and water hold-up by spraying (WHS) was conducted in the experiment. It is found that heat exchanger surface characteristics, spray pressure, spray water temperature and heat exchanger surface temperature play an important role in WHS. In order to evaluate relationship between WHS and surface characteristics, test conditions are determined through a contour analysis. A correlation was proposed to predict WHS as a function of DCA. With its test efficiency and consuming time, the prediction method can be used to evaluate WHS performance.

• Korean Journal of Environment and Ecology
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• v.16 no.4
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• pp.421-432
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• 2003

To investigate the vegetation structure of mountain ridge from Jeongryongchi to Bokseongiiae in Baetdudaegan, thirty few sites(size 500$m^2$) were set up and surveyed. By using TWINSPAN and DCA technique, the Plants community was divided into four groups, those are Pinus densiflora - P. rigida community, P. denisiflora community, P. densiflora -Larix leptolepis community, Quercus mongolica cummunity. P densiflora is turned out as a dominant woody species in the ridge area. Diversity index of the species in ridge area which is semi mountainous one, is lower than one of mountainous ridge area.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.3
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• pp.62-73
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• 2012

IEEE 802.15.4 standard which has low-speed, low-power, low-cost can be efficiently used in wireless sensor network environment. Among various topologies used in IEEE 802.15.4 standard, a cluster-tree topology which has many nodes in it, transmit delay, energy consumption and data loss due to traffic concentration around the sink node. In this paper, we propose the MRS-DCA algorithm that minimizes conflicts between packets for efficient data transmission, and dynamically allocates the active period for efficient use of limited energy. The MRS-DCA algorithm allocates RP(Reservation Period) to the active period of IEEE 802.15.4 and guarantees reliable data transmission by allocating RP and CAP dynamically which is based on prediction using EWMA. The comparison result shows that the MRS-DCA algorithm reduces power consumption by reducing active period, and increasing transmission rate by avoiding collision.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7A
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• pp.693-701
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• 2008

In OFDMA (Orthogonal Frequency Division Multiple Access) system that frequency reuse factor is 1, as the same channels in the neighborhood cells creates inter-cell co-channel interference which provides a resource underutilization problem, channel allocation schemes to minimize inter-cell interference have been studied. This paper proposes a new CNIR (Carrier to Noise and Interference Ratio)-based distributed Inter-cell DCA (Dynamic Channel Allocation) algorithm in the OFDMA environment with frequency reuse factor of 1. When a channel allocation is requested, if there is not a free channel in home cell or the available free channels in home cell do not satisfy a required threshold value, the proposed Inter-cell DCA algorithm finds CNIR values of available free channels in the neighborhood cells and then allocates a free channel with maximum CNIR value. Through the simulation results, we find that the proposed scheme decreases both new call block rate and forced termination rate due to new call generation at the same time because it increases channel allocation probability.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1583-1587
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• 2015

Bile acids are endogenous metabolites that aid in the digestion and absorption of ingested fat and fat-soluble vitamins. However, high concentrations of deoxycholic acid (DCA) in the colon are associated with high incidence of colorectal cancer. In the present study, the binding of persimmon extracts to DCA in order to decrease inflammatory stress induced by DCA in a small intestinal epithelial cell line, Caco-2, was investigated. Young and ripened persimmons were extracted with distilled water (DW), ethanol, and acidic ethanol. Further, DW extract residue was re-extracted with acidic ethanol. Of the obtained extracts, acidic ethanol extract of young persimmon showed the highest bile-acid binding capacity. Moreover, acidic ethanol extract of young persimmon significantly inhibited nitric oxide production in Caco-2 cells stimulated with DCA and prevented significant reduction of trans-epithelial electric resistance. Based on these results, acidic ethanol extract of young persimmon can be used as a functional ingredient to enhance gastrointestinal health.