• Journal of Wetlands Research
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• v.15 no.4
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• pp.535-541
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• 2013

The urbanization affects significantly on a natural water circulation system by increasing the imperviousness rate. It is also negatively affecting on urban temperature, environmental pollution, water quality, and aqua-ecosystems. The Korea MOE (Ministry of Environment) adapted a new environmental policy in order to reduce the impact of urbanization, which is the Green Stormwater Infrastructure (GSI) program. The GSI can be achieved by protecting conservable green spaces, enlarging more green spaces, and constructing more permeable pavements. The GSI is including many different techniques such as bioretention, rain garden, infiltration trench and so on. Also It is the infrastructures using natural mechanisms of soils, microorganisms, plants and animals on a water circulation system and pollutant reduction. In this research, a multi functional GSI technology with infiltration-filtration mechanisms has been developed and performed lab-scale tests to evaluate the performances about infiltration rate restoration and pollutant reduction. The most of pollutants including metals, organics and particulates were reduced about 50~90% due to water infiltration and storage functions. The clogging was found when the TSS loading rate was reached on $8.3{\sim}9.0kg/m^2$, which value is higher than the values in literatures. It means the new technology can show high performances with low maintenances.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.47 no.6
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• pp.28-39
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• 2010

The study aims at offering a solution to the problems of transmission delay and data throughput decrease as the number of contending On-Board Units (OBU) increases by applying CSMA medium access control protocol based upon IEEE 802.11p. In a competition-based medium, contention probability becomes high as OBU increases. In order to improve the performance of this medium access layer, the author proposes EDCA which a adaptive adjustment of the Contention Windows (CW) considering traffic density and data type. EDCA applies fixed values of Minimum Contention Window (CWmin) and Maximum Contention Window (CWmax) for each of four kinds of Access Categories (AC) for channel-specific service differentiation. EDCA does not guarantee the channel-specific features and network state whereas it guarantees inter-AC differentiation by classifying into traffic features. Thus it is not possible to actively respond to a contention caused by network congestion occurring in a short moment in channel. As a solution, CWminAS(CWmin Adaptation Scheme) and ACATICT(Adaptive Contention window Adjustment Technique based on Individual Class Traffic) are proposed as active CW control techniques. In previous researches, the contention probabilities for each value of AC were not examined or a single channel based AC value was considered. And the channel-specific demands of IEEE 802.11p and the corresponding contention probabilities were not reflected in the studies. The study considers the collision number of a previous service section and the current network congestion proposes a dynamic control technique ACCW(Adaptive Control of Contention windows in considering the WAVE situation) for CW of the next channel.

• Journal of KIISE:Software and Applications
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• v.31 no.8
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• pp.1092-1100
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• 2004

An E-mails have regarded as one of the most popular methods for exchanging information because of easy usage and low cost. Meanwhile, exponentially growing unwanted mails in user's mailbox have been raised as main problem. Recognizing this issue, Korean government established a law in order to prevent e-mail abuse. In this paper we suggest hybrid spam mail filtering system using weighted Bayesian classifier which is extended from naive Bayesian classifier by adding the concept of preprocessing and intelligent agents. This system can classify spam mails automatically by using training data without manual definition of message rules. Particularly, we improved filtering efficiency by imposing weight on some character by feature extraction from spam mails. Finally, we show efficiency comparison among four cases - naive Bayesian, weighting on e-mail header, weighting on HTML tags, weighting on hyperlinks and combining all of four cases. As compared with naive Bayesian classifier, the proposed system obtained 5.7% decreased precision, while the recall and F-measure of this system increased by 33.3% and 31.2%, respectively.

• Journal of KIISE
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• v.42 no.3
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• pp.367-378
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• 2015

This study was directed at the design of a hybrid algorithm for competition relation extraction. Previous works on relation extraction have relied on various lexical and deep parsing indicators and mostly utilize only the machine learning method. We present a new algorithm integrating machine learning with various filtering methods. Some simple but useful features for competition relation extraction are also introduced, and an optimum feature set is proposed. The goal of this paper was to increase the precision of competition relation extraction by combining supervised learning with various filtering methods. Filtering methods were employed for classifying compete relation occurrence, using distance restriction for the filtering of feature pairs, and classifying whether or not the candidate entity pair is spam. For evaluation, a test set consisting of 2,565 sentences was examined. The proposed method was compared with the rule-based method and general relation extraction method. As a result, the rule-based method achieved positive precision of 0.812 and accuracy of 0.568, while the general relation extraction method achieved 0.612 and 0.563, respectively. The proposed system obtained positive precision of 0.922 and accuracy of 0.713. These results demonstrate that the developed method is effective for competition relation extraction.

• Journal of Microbiology and Biotechnology
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• v.24 no.5
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• pp.597-604
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• 2014

$\small{D}$-Phenylglycine aminotransferase ($\small{D}$-PhgAT) from Pseudomonas stutzeri ST-201 is useful for enzymatic synthesis of enantiomerically pure $\small{D}$-phenylglycine. However, its low protein solubility prevents its application at high substrate concentration. With an aim to increase the protein solubility, the N-terminus of $\small{D}$-PhgAT was genetically fused with short peptides ($A_1$ ${\alpha}$-helix, $A_2$ ${\alpha}$-helix, and ALAL, which is a hybrid of $A_1$ and $A_2$) from a ferredoxin enzyme of a halophilic archaeon, Halobacterium salinarum. The fused enzymes $A_1$-$\small{D}$-PhgAT, $A_2$-$\small{D}$-PhgAT, and ALAL-$\small{D}$-PhgAT displayed a reduced pI and increased in solubility by 6.1-, 5.3-, and 8.1- fold in TEMP (pH 7.6) storage, respectively, and 5-, 4.5-, and 5.9-fold in CAPSO (pH 9.5) reaction buffers, respectively, compared with the wild-type enzyme (WT-$\small{D}$-PhgAT). In addition, all the fused $\small{D}$-PhgAT displayed higher enzymatic reaction rates than the WT-DPhgAT at all concentrations of L-glutamate monosodium salt used. The highest rate, $23.82{\pm}1.47$ mM/h, was that obtained from having ALAL-$\small{D}$-PhgAT reacted with 1,500 mM of the substrate. Moreover, the halophilic fusion significantly increased the tolerance of $\small{D}$-PhgAT in the presence of NaCl and KCl, being slightly in favor of KCl, where under the same condition at 3.5 M NaCl or KCl all halophilic-fused variants showed higher activity than WT-$\small{D}$-PhgAT.

• Journal of Broadcast Engineering
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• v.10 no.4 s.29
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• pp.548-556
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• 2005

In wireless network environments, wireless channels are characterized by time-varying fading and interference conditions, which may lead to burst packet corruptions and delay variation. This can cause severe quality degradation of streaming media. To guarantee successful transmission of media over the hostile wireless networks, where channel conditions are highly fluctuating, a flexible and network-adaptive transport method is required. Thus, we propose a network-adaptive transport error control consisting of packet-level interleaved FEC and delay-constrained ARQ, which acts as an application-level transport method of streaming media to alleviate burst packet losses while adapting to the changing channel condition in wireless networks. The performances of the proposed network-adaptive transport error control, general error control schemes, and hybrid schemes are evaluated by a developed simulator at the transport-level and video quality of streaming media. Simulation results show that the proposed mechanism provides the best overall performance among compared other schemes in terms of the transport-level performance of error control and the performance of video quality for streaming media.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.651-654
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• 2011

Cymbidium 'Orange Bowl' (Lucky Rainbow 'Randevous' ${\times}$ 'Eastern Star') was developed from a cross between hybrids at the National Institute of Horticultural & Herbal Science, Rural Development Administration in 2006. A cross was made between the pink colored flower C. Lucky Rainbow 'Randevous' as maternal line and pure yellow colored flower, C. 'Eastern Star' as paternal line in 1995. The seed germination, cultivation, selection, and characteristic trials were conducted from 1996 to 2006. The line was named as Wongyo F1-18 and phenotype was characterized in 2006 as a new 'Orange Bowl'. The 'Orange Bowl' has having light yellow basal color (RHS, YO21D) and orange line (RHS, OR30B) on both of sepal and petal with red lip (RHS, OR30B). 'Orange Bowl' has about 10.9 flowers per flower stalk and flower size of 7.4 cm. General appearance of the petals and sepals is slightly incurved shape. The plant size is intermediate having erect peduncle. Blooming is started from the late of January (mid winter) under optimal culture condition. Leaf attitude and twisting is half- erect and very weak respectively. This hybrid has attractive floral arrangement, long flower stalk (71.8 cm) and vigorous growth. We expect that 'Orange bowl' has a great potential for exporting to Chinese market.

• Journal of Microbiology and Biotechnology
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• v.11 no.6
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• pp.915-921
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• 2001

Phytase improves the bioavailability of phytate phosphorus in plant foods to humans and animals, and reduces the phosphorus pollution of animal waste. In order to express a high level of fungal phytase in Saccharomyces cerevisiae, various expression vectors were constructed with different combinations of promoters, translation enhancers, signal peptides, and terminator. Three different promoters fused to the phytase gene (phyA) from Aspergillus niger were tested: a galactokinase (GAL1) promoter, glyceraldehyde-3-phosphate dehydrogenase (GPD) promoter, and yeast hybrid ADH2-GPD promoter consisting of alcohol dehydrogenase II (ADH2) and a GPD promoter. The signal peptides of phytase, glucose oxidase (GO), and rice amylase 1A(RAmy1A) were included. Plus, the translation enhancers of the ${\Omega}$ sequence and UTR70 from the tobacco mosaic virus (TMV) and spinach, respectively, were also tested. Among the recombinant vectors, pGphyA06 containing the GPD promoter, the ${\Omega}$ sequence, RAmy1A, and GAL7 terminator expressed the highest phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase activity in a culture filtrate, which was estimated at 20 IU/ml. An intracellular localization of the expressed phytase was also performed by inserting an endoplasmic reticulum (ER) retention signal, KDEL sequence, into the C-terminus of the phytase within the vector pHphyA-6. It appeared that the KDEL sequence directed most of the early expression of phytase into the intracellular compartment yet more than $60\%$ of the total phytase activity was still retained within the cell even after the prolonged (>3 days) incubation of the transformant. However, the intracellular enzyme activity of the transformant without a KDEL sequence was as high as that of the extracellular one, thereby strongly suggesting that the secretion of phytase in S. cerevisiae appeared to be the rate-limiting step for the expression of a large amount of extracellular recombinant phytase, when compared with other yeasts.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.67-71
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• 2008

The goal of this study was to vinify four varieties of grapes, namely Vitis labrusca L (Gerbong), Vitis labrusca B (Campbell Early), Vitis labrusca (Muscat Bailey A) and Vitis hybrid (Sheridan), and to investigate the changes in the physicochemical properties and antioxidant activity of the red wines during fermentation and post-fermentation. The ethanol content of the four red wines varied only slightly from 11.4%-12.8%, indicating that no significant change occurred during the fermentation and post-fermentation. The total anthocyanin and phenol contents as bioactive compounds were the highest level in the Vitis labrusca B red wine. The antioxidant activity was also the highest of 88.9% after 10 days fermentation in the Vitis labrusca B red wine and showed from only 36.6% to 61.7% in the other red wines, though the range decreased to 33.1%-64.1% during post-fermentation for 120 days at $4^{\circ}C$. Our results show that the vitis labrusca B red wine has the potential to become a functional red wine because of its high antioxidant activity.

• Journal of KIISE:Databases
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• v.37 no.6
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• pp.308-314
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• 2010

As the price of flash memory continues to drop and the technology of flash SSD controller innovates, high performance flash SSDs with affordable prices flourish in the storage market. Nevertheless, it is hard to expect that flash SSDs will replace harddisks completely as database storage. Instead, the approach to use flash SSD as a cache for harddisks would be more practical, and, in fact, several hybrid storage architectures for flash memory and harddisk have been suggested in the literature. In this paper, we propose a new approach to use flash SSD as an extended buffer for main buffer in database systems, which stores the pages replaced out from main buffer and returns the pages which are re-referenced in the upper buffer layer, improving the system performance drastically. In contrast to the existing approaches to use flash SSD as a cache in the lower storage layer, our approach, which uses flash SSD as an extended buffer in the upper host, can provide fast random read speed for the warm pages which are being replaced out from the limited main buffer. In fact, for all the pages which are missing from the main buffer in a real TPC-C trace, the hit ratio in the extended buffer could be more than 60%, and this supports our conjecture that our simple extended buffer approach could be very effective as a cache. In terms of performance/price, our extended buffer architecture outperforms two other alternative approaches with the same cost, 1) large main buffer and 2) more harddisks.