• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1366-1370
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• 2013

A series of phosphorescent iridium(III) complexes 1-4 based on phenylpyrazole were synthesized and their photophysical properties were investigated. To evaluate their electroluminescent properties, OLED devices with the structure of ITO/NPB/mCP: 8% Iridium complexes (1-4)/TPBi/Liq/Al were fabricated. Among those, the device with 3 showed the most efficient white emission with maximum luminance of 100.6 $cd/m^2$ at 15 V, maximum luminous efficiency of 1.52 cd/A, power efficiency of 0.71 lm/W, external quantum efficiency of 0.59%, and CIE coordinates of (0.35, 0.40) at 15.0 V, respectively.

• Speech Sciences
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• v.10 no.1
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• pp.71-84
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• 2003

In the acoustic modeling for large vocabulary speech recognition, a sparse data problem caused by a huge number of context-dependent (CD) models usually leads the estimated models to being unreliable. In this paper, we develop a new clustering method based on the C45 decision-tree learning algorithm that effectively encapsulates the CD modeling. The proposed scheme essentially constructs a supervised decision rule and applies over the pre-clustered triphones using the C45 algorithm, which is known to effectively search through the attributes of the training instances and extract the attribute that best separates the given examples. In particular, the data driven method is used as a clustering algorithm while its result is used as the learning target of the C45 algorithm. This scheme has been shown to be effective particularly over the database of low unknown-context ratio in terms of recognition performance. For speaker-independent, task-independent continuous speech recognition task, the proposed method reduced the percent accuracy WER by 3.93% compared to the existing rule-based methods.

• Journal of Soil and Groundwater Environment
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• v.7 no.3
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• pp.71-77
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• 2002

This research was carried out from 2001. 4 until 2001. 5 in order to examine the level of soil contamination in the vicinity of Nanjido. The sampling was done at near the Nanjido soil. At the each sampling site we did the sampling at different depth- surface(0~15cm deep), 1m deep, 2m deep, 3m deep. The contamination of Cd, Cu, Pb, As, $Cr^{+6}$, and Hg were tasted and analysed by spectra AA. The examination showed that the average concentration level of the entire sampled soil was Cd, 0.229mg/kg, Cu 8.349mg/kg, Pb : 11.083mg/kg, As : 0.298mg/kg, $Cr^{+6}$ : 0.124mg/kg, and Hg : 0.134mg/kg. The concentration level of at the depth of 0-l5cm, came out to be Cd : 0.305mg/kg, Cu : 8.464mg/kg, Pb : 11 383mg/kg, As : 0.128mg/kg, $Cr^{+6}$ : 0.153mg/kg, and Hg : 0.092mg/kg. It shows that in the cases of Cd and C $r^{+6}$ the average concentration level of the whole sampled soil was about 80% of that of 0-l5cm depth. And as for Hg and As. the average concentration level of the entire sampled soil came out to be approximately twice as high as the sample soil from the depth surface, As for Cu and Pb, there was not much difference between the entire samples average concentration level and the concentration level of surface. It was hard to find much relationship between the depth of each site where sampling was done and the level of concentration, the concentration level of Pb and Cu at the sampling site C and E was quite high, which suggests that it has been affected by the polluted the hyang-dong stream and fill random up waste.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.90-98
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• 1996

The mineral contents were analyzed for 12 varieties of Korean apples and 9 commercial apple juices by atomic absorption spectrophotometry. On the fresh matter basis, the ash contents of tested apples ranged 0.21-0.48%, Mn 0.20-2.52 ppm, Cu 0.10-1.03 ppm, Fe 0.24-9.88 ppm, Zn 0.09-1.06 ppm, Mg 21.08-99.00 ppm, Ca 15.16-99.56 ppm, K 842.10-1788.10 ppm, Na 10.32-40.53 ppm, P 24.43-90.07 ppm, Pb nd-98.05 ppb, Cd nd-36.08 ppb and Cr 2.25-123.76 ppb. Overally mineral contents of Aori and Jonathan were higher than those of Fuji. The mineral contents of apple cultivated at Wonju, Kangwon and Taegu, $Ky{\check{o}}ngbuk$ were higher than those of the other growing region. The mineral contents of commercial apple juice were ash 0.13-0.36%, Mn 0.24-0.99 ppm, Cu 0.10-0.61 ppm, Fe 0.19-3.70 ppm. Zn 0.20-1.77 ppm, Mg 18.16-49.56 ppm, Ca 14.42-42.30 ppm, K 785.07-1440.30 ppm, Na 14.71-52.58 ppm, P 16.57-63.56 ppm, Pb nd-95.55 ppb, Cd nd-17.65 ppb and Cr 8.60-110.98 ppb, respectively. Comparing mineral contents of apples and commercial apple juices, Cu, Mg, K, Ca and Fe contents of apples were higher and Zn, Na contents were lower than those of apple Juices.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.6 no.2
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• pp.138-145
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• 2007

Luminous traffic safety mark is restricted to use only the place that has a thick fog, many night traffic accidents, limited field of view due to structure of road. Recently, LEDs are used for luminous traffic safety mark, but we propose an organic LED for a novel luminous traffic safety mark in the near future. The device structure was $ITO/2-TNATA(500{\AA})/{\alpha}-NPD(200{\AA})/DPVBi(300{\AA})/BCP(10{\AA})/Alq_3(200{\AA})/LiF(10{\AA})/Al:Li(1000{\AA})$. The characteristics of the device are most efficient on occasion of using $N_2$ gas plasma treatment. Current density is $240.71mA/cm^2$ luminance $10,550cd/m^2$, and current efficiency 3.53cd/A at an applied voltage of 10V. The maximum EL wavelength of the fabricated blue organic light-emitting device is 456nm. CIE color coordinates are x=0.1449 and y=0.1633, which is similar to NTSC deep-blue color with CIE color coordinates of x=0.14 and y=0.08.

• Applied Biological Chemistry
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• v.40 no.4
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• pp.342-346
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• 1997

Contents of heavy metals in paddy soils and brown rice of near the Kunsan industrial complex area were investigated. Average total heavy metal contents in paddy soils were Pb 34.33, Cd 0.50, Cu 35.49, and Zn 71.67 mg/kg respectively. There are no correlation between distances from industrial complex and contents of heavy metals in paddy soils. Average contents of heavy metals in brown rice grown above paddy soil were Pb 1.74, Cd 0.07, Cu 3.54, and Zn 16.53 mg/kg. Relationships between 0.1N HCl soluble heavy metals in paddy soils and contents of brown rice showed positive significant correlations for Pb at l% $level(r=0.6853^{**})$ and for Zn at 5% $level(r=0.5420^*)$. Relationships between total contents of heavy metals in paddy soils and contents of brown rice showed only positive significant correlation for Pb at 1% $level(r=0.7131^{**})$. Contents of heavy metals in paddy soils and brown rice of near the Kunsan industrial complex was polluted partly by the influence of smoke and dust out from industrial complex but not polluted anxious level

• Journal of the Korean Chemical Society
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• v.48 no.2
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• pp.129-136
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• 2004

Titanium and [titanium+Na(K)] substituted 11${\AA}$ tobermorites solids synthesized under hydrothermal conditions at 180$^{\circ}C$ exhibit cation exchange properties toward heavy transition metal cations, such as Fe$^{2+},\;Zn^{2+},\;Cd^{2+}\;and/or\;Pb^{2+}$. The amount of heavy metal cations taken up by these solids was found in the order: Fe$^{2+}>Zn^{2+}>Cd^{2+}>Pb^{2+}$, and reached maximum at 10% [Ti+K]-substituted tobermorite. The total cation exchange capacity of the 10% Ti+Na (K) - substituted tobermorites synthesized here range from 71 to 89 meq/100 g, and 50-56 meq/100g for Ti-substituted only. Results indicated that 10% [Ti+K] substitution exhibit cation exchange capacity more 2.4 times than the unsubstituted-tobermorite. This is due to the increase of the number of active sites on the exchangers. The incorporation of Ti and/or [Ti+Na(K)] in the lattice structure of synthesized tobermorites is due to exchange of Ti$^{4+}{\Leftrightarrow}2Ca^{2+}\;and/or\;Ti^{4+}+2Na^+(K^+){\Leftrightarrow}3Ca^{2+}$, respectively. The mechanism of Ti and [Ti+Na(K)] incorporations in the crystal lattice of the solids during synthesis and the heavy metal cations uptaken by these solids is studied.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.2
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• pp.93-102
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• 2011

In this study, experiments on total digestion and sequential extraction were conducted in order to understand total metal contents, and mobility, bioavaliability and toxicity of metals in marine dredged sediment from Busan New Port. The total concentrations of arsenic and heavy metals in the dredged sediment were relatively low as follows: Al (2.36~2.96 wt.%), As (1.6~3.3 mg/kg), Ba (30.0~33.8 mg/kg), Cd (0.12~0.18 mg/kg), Cr (27.5~35.0 mg/kg), Cu (11.3~15.0 mg/kg), Fe (2.91~3.51 wt.%), Mn (324~408 mg/kg), Ni (18.8~23.8 mg/kg), Pb (23.8~31.3 mg/kg), and Zn (70.0~86.3 mg/kg). In addition, it was found that most of Al (87.5~95.9%), As (74.1~93.8%), Ba (71.8~77.6%), Cr (69.5~94.3%), Cu (50.0~78.7%), Fe (70.8~87.6%), Ni (64.5~75.3%), Pb (53.4~64.3%), and Zn (62.5~81.7%) existed in the residual fraction, meaning that those elements might come from natural sources. On the other hand, Cd and Mn were present mainly in the non-residual fraction. Due to low concentrations of toxic heavy metals and high percentage of residual fraction, it could be possible to reuse the dredged sediment for bricks, pavement base material, etc.

• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.71-80
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• 2012

Vinca alkaloids produced from Catharanthus roseus are one of the most important natural product drugs in treatments of human cancers. These anticancer drugs are derived from coupling of the two monomeric indole alkaloids, catharanthine and vindoline. In order to investigate vindoline biosynthesis, tabersonine-$CD_3$ 1a is synthesized to use as a deuterium labeled precursor, which is distinguished clearly from the natural counterpart. We show that these deuterium labeled tabersonine 1a are successfully incorporated into the vindoline biosynthetic pathway to yield three deuterated vindoline intermediates. 16-Hydroxytabersonine-$CD_3$ (m/z 356) 2a, 16-Methoxytabersonine-$CD_3$ (m/z 370) 3a, 16-Methoxy-2,3-dihydro-3-hydroxytabersonine-$CD_3$ (m/z 388) 4a are produced from the cell suspension culture measured by UPLC/MS at 5 and 13 days after feeding tabersonine. The conversion rates from 1a to 2a and 2a to 3a are fast, whereas that from 3a to 4a is much slower. This indicates that the rate determining step among the first three vindoline biosynthesis is the last step. As a result of the slow conversion rate from 3a to 4a, the accumulation level of 16-Methoxytabersonine-$CD_3$ 3a is significantly increased up to 13 days. The accumulation ratio among 2a, 3a and 4a is 1, 2 and 0.1 at 5 days. However, the peaks of desacetoxyvindoline-$CD_3$ 5a, deacetylvindoline-$CD_3$ 6a and vindoline-$CD_3$ 7a are not found from the cell extracts even after 13 days of incubation which may indicate no presence of their corresponding enzymes.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.71-74
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• 1996

본 연구에서는 반복 학습제어 이론을 기초로 하는 하이브리드 신경망 제어기를 제안한다. 신경망으로는 백프로퍼게이션(backpropagation) 신경망을 사용하고, 기존의 반복 학습 제어 이론의 단점을 보안한 제어 알고리즘을 제안한다. 백프로퍼게이션 신경망의 맵핑(mapping)의 특징으로 원하는 목표 패턴에 추종할 수 있는 출력 패턴을 생성하고 반복 학습에 소요되는 학습시간을 줄일 수 있다. 실험결과에서 보듯이 제안된 제어 알고리즘은 목표패턴에 수렴함을 알 수 있다. 제시한 알고리즘은 CD-ROM 드라이브와 같은 광디스크 드라이브류의 초점 제어 등에 응용할 수 있다.