• Journal of Korean Society for Atmospheric Environment
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• v.34 no.3
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• pp.406-417
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• 2018

In this study, $PM_{2.5}$ samples were collected during approximately 3 years in Chuncheon, a small residential and tourist city, in Korea. The average $PM_{2.5}$ concentration was $26.9{\mu}g/m^3$, exceeding the annual national air quality standard. $PM_{2.5}$ showed typical seasonal variation, having higher concentration in winter and lower concentration in summer. Sixteen metallic elements in $PM_{2.5}$ were also analyzed, and K was the highest contributor especially in late fall and winter. In addition, K considerably increased for the top 10% of $PM_{2.5}$ samples and showed the highest correlation coefficient with $PM_{2.5}$ among all other metallic elements. These results suggest that the combustion of agricultural residue and other biomass, the major source of K was likely to be important to high $PM_{2.5}$ concentration events in this city. Crustal elements including Al, Fe, Si, Ti, Mg showed high concentration in spring while Cr, Cu and Ni were relatively consistent throughout a year. Principal component analysis was used to trace the sources, and soil re-suspension, combustion of biomass and fossil fuels, and asphalt concrete production were identified as the main sources of $PM_{2.5}$.

• Applied Biological Chemistry
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• v.33 no.1
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• pp.62-67
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• 1990

The volatile oils of the fresh leaf and seed of parsley(Petroselinum crispum) were isolated by simultaneous steam distillation and extraction procedure. The compositions of the resulting oils were investigated by gas chromatography and gas chromatography-mass spectrometry. The volatile oil contents of leaf and seed were 0.06 % and 3.11 %, respectively. Fifty-eight components including 15 partially characterized components were identified in leaf oil and 23 components in seed oil. Seven of them are suggested as new parsley leaf volatiles. Terpenoids were represented as much as 46.4 % of total leaf volatiles and 49.3 % of total seed volatiles. The leaf volatiles contained a lot of myrcene(3.02%), 4-isopropenyl-1-methyl benzene(4.52%) and p-1,3,8-menthatriene(10. 49 % ), but the seed volatiles were characterized by greater quantities of the isomers, ${\alpha}-pinene$(22.28 %) and ${\beta}-pinene$(16.20 %), although these compounds were contained only trace in leaf volatiles. Of the components identified in both oils, the most abundant component was myristicin, constituting 21.80 % of the leaf volatiles and 47.54 % of the seed volatiles.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.263-270
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• 2014

This paper was researched that provenance of the raw material for bronze relics excavated Cheonghaejin using the distribution of lead isotope ratio based on galena ores of South Korea. Also we want to make sure that the trace elements appearing as a by-product can be used as a secondary indicator for provenance research. In the case of the galena map of the East-North Asia (Mabuchi, 1985), data are plotted in China area. Therefore it is estimated that most bronzes were produced with lead ore from China. On the other hand, the same data are plotted in the Okcheon Metamorphic Belt and Yeongnam Massif of the galena map of South Korea (KOPLID, 2012). Also the contents of Ag and Sb are available as indicator due to separate ores from similar zone in lead isotope ratio.

• Journal of Periodontal and Implant Science
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• v.25 no.2
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• pp.181-191
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• 1995

The ability of fibroblasts attach to teeth is of paramount imporance in re-establishing the lost connective tissue attachment after periodontal therapy. Tobacco contains a complex mixture of substances including nicotine. various nitrousamines, trace elements. and a variety of poorly characterized substances. The effects of nicotine on fibroblasts have reported an altered morphology and attachment of fibroblasts to substrates and disturbances in protein synthesis and secretion. This study examined the effect of nicotine, a major component of the particulate phase of tobacco smoke, on human gingival fibroblasts and periodontal ligament cells attachment to tissue culture surfaces and cellular activity of human gingival fibroblasts and periodontal ligament cells. Pooled human gingival fibroblasts made from extraction of 3rd molar were utilized between passage 4 and 5 and plated in 96 well plate at 20,000 cells per well. Cell number were determined using 3-(4,5-dimethylthiazole-2-y)2,5-diphenyltetrazolium bromide(MTI) , which is reflection of mitochondrial dehydrogenase activity. The concentration of nicotine used were 0.025, 0.05, 0.1, 0.2 and $0.4{\mu}M$, the average serum concentration for a smoker being approximately $0.1{\mu}M$. The results were as follows : 1. Attachment effects of nicotine on human gingival fibroblasts and periodontal ligament cells Excepts of $0.4{\mu}M$, the effects on attachment with increasing numbers of cells attaching with increasing nicotine concentrations, compared to control group. But over the 60min, return to control value. 2. The effect of cellular activity on human gingival fibroblasts and periodontal ligament cells. The cellular activity of human gingival fibroblasts and periodontal ligament cells were similar or decrease to control value at 1st incubation day. At 2nd incubation day, 0.05, 0.1, 0.2, $0.4{\mu}M$ concentrations were statistically different from control value on gingival fibroblasts group. But at 3rd incubation day, cellular activities of all experimental group were significantly decrease than control group.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.5 no.1
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• pp.21-24
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• 1999

The analysis of hazard compounds, including naphthalene, biphenyls (BP) and diethyl phthalate (DEP), was conducted from the wooden kitchenwares and sanitory produce. Fifty samples of that wooden products in the local market were purchased for the study. All the samples were extracted by benzene and n-heptane, followed by the analysis through GC-MSD. As a result, neither naphthalene nor diethyl phthalate were found, however, trace amount of biphenyls were detected on all the samples ranged from 0.1 to 3.1 ppm. Biphenyls also contained both in the imported and the domestic of White Birch wood, as 0.25 ppm and 0.34 ppm, respectively. The concentration of biphenyls reduced with the process of the original woods, and especially the detection range was relatively low compared with the permission one of apples (110 ppm). The results suggested that biphenyls were contaminated into the product not by the addition doting the process of manufacture, but as the component itself in raw wood materials. Also, the content of the residual biphenyls were not suspected to give the harmful effects.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.682-691
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• 2017

In this paper, we propose the fusion design methodology of both pedestrian detection and object tracking system realized with the aid of HOG-PCA based RBFNN pattern classifier. The proposed system includes detection and tracking parts. In the detection part, HOG features are extracted from input images for pedestrian detection. Dimension reduction is also dealt with in order to improve detection performance as well as processing speed by using PCA which is known as a typical dimension reduction method. The reduced features can be used as the input of the FCM-based RBFNNs pattern classifier to carry out the pedestrian detection. FCM-based RBFNNs pattern classifier consists of condition, conclusion, and inference parts. FCM clustering algorithm is used as the activation function of hidden layer. In the conclusion part of network, polynomial functions such as constant, linear, quadratic and modified quadratic are regarded as connection weights and their coefficients of polynomial function are estimated by LSE-based learning. In the tracking part, object tracking algorithms such as mean shift(MS) and cam shift(CS) leads to trace one of the pedestrian candidates nominated in the detection part. Finally, INRIA person database is used in order to evaluate the performance of the pedestrian detection of the proposed system while MIT pedestrian video as well as indoor and outdoor videos obtained from IC&CI laboratory in Suwon University are exploited to evaluate the performance of tracking.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.366-372
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• 2009

This study looked at toxicity of Mediterranean mussels, Mytilus galloprovincialis, which had accumulated paralytic shellfish toxins (PST) from early March to late May 2005 at Jinhae Bay, Korea. Alexandrium sp. was observed in low densities (< 1,000 cells/L) at the beginning of the study in March, increased rapidly in April, declined rapidly and disappeared in May. Although low densities of Alexandrium sp. were observed in March, mussel toxicity exceeded regulation level ($80{\mu}g$ STXeq. /100 g). Peak PSP (Paralytic Shellfish Poisoning) toxicity in the mussels occurred during high Alexandrium sp. cell densities in April. Mussels toxicity decreased with decline of Alexandrium sp. cell density. Major toxin components identified were $GTX_1$, $GTX_4$, followed by $C_1$, $C_2$, $GTX_2$, $GTX_3$ and neoSTX. Trace or sporadic toxin components were STX, $GTX_5$, $dcGTX_2$, $dcGTX_3$ and dcSTX. Toxin component analysis from the middle to end of the study showed that $11{\beta}$-epimers ($GTX_{3,4}$, $C_2$) were converted into $11{\alpha}$-epimers ($GTX_{1,2}$, $C_1$) and started to determine STX.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.183-183
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• 2012

In the era of 45 nm or beyond technology, conventional etch mask using photoresist showed its limitation of etch mask pattern collapse as well as pattern erosion, thus hard mask in etching became necessary for precise control of etch pattern geometry. Currently available hard mask materials are amorphous carbon and polymetric materials spin-on containing carbon or silicon. Amorphous carbon layer (ACL) deposited by PECVD for etch hard mask has appeared in manufacturing, but spin-on carbon (SOC) was also suggested to alleviate concerns of particle, throughput, and cost of ownership (COO) [1]. SOC provides some benefits of reduced process steps, but it also faced with wiggling on a sidewall profile. Diamond like carbon (DLC) was also evaluated for substituting ACL, but etching selectivity of ACL was better than DLC although DLC has superior optical property [2]. Developing a novel material for pattern hard mask is very important in material research, but it is also worthwhile eliminating a potential issue to continuously develop currently existing technology. In this paper, we investigated in-situ dry-cleaning (ISD) monitoring of ACL coated process chamber. End time detection of chamber cleaning not only provides a confidence that the process chamber is being cleaned, but also contributes to minimize wait time waste (WOW). Employing Challenger 300ST, a 300mm ACL PECVD manufactured by TES, a series of experimental chamber cleaning runs was performed after several deposition processes in the deposited film thickness of $2000{\AA}$ and $5000{\AA}$. Ar Actinometry and principle component analysis (PCA) were applied to derive integrated and intuitive trace signal, and the result showed that previously operated cleaning run time can be reduced by more than 20% by employing real-time monitoring in ISD process.

• Applied Biological Chemistry
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• v.26 no.1
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• pp.58-64
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• 1983

The fatty acid composition of phospholipid from the leaves of rice plants grown at $28^{\circ}C$ and harvested at the 3-4 leaf stage was determined for 8 cultivars. Change among cultivars observed in the composition has been found to be correlative to the chilling susceptivity of the plants at the given leaf-stage. The chilling-resistant cultivars contain phospholipid with higher degree of unsaturation and larger relative proportion of unsaturated fatty acids than the chilling-sensitive ones. The indices for unsaturation of phospholipid from a cultic-ar are well in accordance with its resistance to cold damage. clearly demonstrating that the fluidity of biomembrane which is generally regarded as the prerequisite for a cell to maintain its membrane-related physiological activity at a low temperature is exclusively controlled by the fatty acid composition of phospholipid. Also identified were the components of phospholipid, which are phosphatidyl serine and phosphatidyl coline as major components and phosphatidyl inositol as minor component plus 3 phospholipids in trace proportion, from every cultivar at the early growth-stage.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.81-89
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• 2007

The Viterbi decoder, which employs the maximum likelihood decoding method, is a critical component in forward error correction for digital communication system. However, lowering power consumption on the Viterbi decoder is a difficult task since the number of paths calculated equals the number of distinctive states of the decoder and the Viterbi decoder utilizes trace-back method. In this paper, we propose a method which minimizes the number of operations performed on the comparator, deployed in the SPEC-T Viterbi decoder implementation. The proposed comparator was applied to the ACSU(Add-Compare-Select Unit) and MPMSU(Minimum Path Metric Search Unit) modules on the decoder. The proposed ACS scheme and MPMS scheme shows reduced power consumption by 10.7% and 11.5% each, compared to the conventional schemes. When compared to the SPEC-T schemes, the proposed ACS and MPMS schemes show 6% and 1.5% less power consumption. In both of the above experiments, the threshold value of 26 was applied.