• The KIPS Transactions:PartD
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• v.13D no.4 s.107
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• pp.513-524
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• 2006

Normalization transform is very useful for finding the overall trend of the time-series data since it enables finding sequences with similar fluctuation patterns. The previous subsequence matching method with normalization transform, however, would incur index overhead both in storage space and in update maintenance since it should build multiple indexes for supporting arbitrary length of query sequences. To solve this problem, we propose a single index approach for the normalization transformed subsequence matching that supports arbitrary length of query sequences. For the single index approach, we first provide the notion of inclusion-normalization transform by generalizing the original definition of normalization transform. The inclusion-normalization transform normalizes a window by using the mean and the standard deviation of a subsequence that includes the window. Next, we formally prove correctness of the proposed method that uses the inclusion-normalization transform for the normalization transformed subsequence matching. We then propose subsequence matching and index building algorithms to implement the proposed method. Experimental results for real stock data show that our method improves performance by up to $2.5{\sim}2.8$ times over the previous method. Our approach has an additional advantage of being generalized to support many sorts of other transforms as well as normalization transform. Therefore, we believe our work will be widely used in many sorts of transform-based subsequence matching methods.

• Journal of KIISE:Databases
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• v.34 no.2
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• pp.119-132
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• 2007

In molecular biology, approximate subsequence search is one of the most important operations. In this paper, we propose an accurate and efficient method for approximate subsequence search in large DNA databases. The proposed method basically adopts a binary trie as its primary structure and stores all the window subsequences extracted from a DNA sequence. For approximate subsequence search, it traverses the binary trie in a breadth-first fashion and retrieves all the matched subsequences from the traversed path within the trie by a dynamic programming technique. However, the proposed method stores only window subsequences of the pre-determined length, and thus suffers from large post-processing time in case of long query sequences. To overcome this problem, we divide a query sequence into shorter pieces, perform searching for those subsequences, and then merge their results. To verify the superiority of the proposed method, we conducted performance evaluation via a series of experiments. The results reveal that the proposed method, which requires smaller storage space, achieves 4 to 17 times improvement in performance over the suffix tree based method. Even when the length of a query sequence is large, our method is more than an order of magnitude faster than the suffix tree based method and the Smith-Waterman algorithm.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.3
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• pp.256-260
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• 2008

This paper describes an improvement of mount-time delay in NAND Flash file systems. To improve file system mount performance, this work configures a hierarchical storage system with byte-addressable NVRAM and NAND Flash memory, and let the meta data of a file system allocated in the NVRAM. Since the meta data are stored in NVRAM supporting data integrity some of the items, which are stored in Spare area and Object Header area of NAND Flash memory to control meta data of NAND Flash file system, could be eliminated. And also, this work eliminates the scanning operation of the Object Header area of previous work FRASH1.0. The scanning operation is definitely required to find out the empty Object Header address for storing the Object Header data and provokes a certain amount of performance loss in file generation and deletion. In this work, an implemented file system, so-called FRASH1.5, is demonstrated, featuring new data structures and new algorithms. The mount time of FRASH1.5 becomes twice as fast as that of the FRASH1.0. The performance in file generation gets improved by about $3{\sim}8%$. In particular, for most large-size files, the FRASH1.5 has 8 times faster mount time than YAFFS, without any performance loss as seen in the file generation.

• Analytical Science and Technology
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• v.9 no.4
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• pp.382-391
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• 1996

In this study, 12 different chemical species of fine ceramic($BaTiO_3$) were synthesized as the standard materials for the fast and accurate measurements of X-ray fluorescence spectrometry. Samples were diluted to sixteen times with the filling compound ($Li_2B_4O_7+LiBO_2$) in order to remove the matrix effect, and to get the convenient storage and homogeneity of ingredients. The matrix effects among the ingredients were corrected by the empirical coefficient method based on the Lucas-Tooth and Price model. The standard curve on 12 standard materials containing 15 elements were obtained by using X-ray fluorescence spectrometry at three different laboratories. The correlation factors of BaO, PbO, SrO, $Fe_2O_3$, $La_2O_3$, $SnO_2$, ZnO, $ZrO_2$, CaO indicated the relati vely good agreement over 0.995 among the three different laboratories. $SiO_2$ and $Al_2O_3$ showed the poor linearity because of their low fluorescence intensities.

• Journal of Environmental Impact Assessment
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• v.24 no.5
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• pp.420-431
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• 2015

As biodiversity and climate change have become main issues in recent times, the role of the forest ecosystem has been more important and forest conservation has been highlighted. The purpose of this study is to estimate forest area with high conservation values in Gapyung-gun by considering forest ecosystem services. The indicators of biodiversity, climate regulation, and water regulation were selected for assessment in this study. To assess biodiversity, habitat structural features and distribution characteristics of species were analyzed. Climate regulation and water regulation were assessed through analysis of carbon absorption volume and water storage. The result showed that, 50.1% of the forests in Gapyung-gun had high conservation values. The results were verified by comparing them with distribution tendencies of other environmental maps, which represent forest ecological values, and showed similar distribution tendencies. The study was conducted on only Gapyung-gun in Korea; however, the methods used in this study could be utilized for assessment of other areas to identify forests with high conservation values.

• Korean journal of food and cookery science
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• v.14 no.4
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• pp.313-326
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• 1998

The quality of physical characteristics were measured, using sensory evaluation and mechanical characteristics where different storing temperature and period on Gukhwa-Byung, which is made of different percentages of Gukhwa (0%, Gukhwa powder：1%, 3% and 5%, and Gukhwa flower：1%, 3% and 5%) were added to rice flour, to promote the use of and liking for rice cakes that are a kind of korean traditional foods. The sensory evaluation showed that it is generally fine right after being made. Especially group F3 was evaluated the best for color, feeling after-swallow and overall-quality. As for color alone, it fumed out to be most distinctive in group F3 after storing 24 hours at 4$^{\circ}C$, in group F1 after 24 hours at 10$^{\circ}C$, in group F1 and F3 after 24 hours at 30$^{\circ}C$ and in group F1 after 48 hours at 30$^{\circ}C$, Gukhwa-Byung added with Gukhwa flower takes the higher degree of preference than the one with Gukhwa powder. Moisture decreased and overall-quality deteriorated as the storing time passed. The value of lightness in the color of Gukhwa-Byung, reduced as Gukhwa content increased and storing temperature rose. The values of red color and yellow color increased as Gukhwa content increased. In a mechanical texture measurement, springiness was high in group P5 right after being made. And it was high after storing 72 hours at 4$^{\circ}C$ and after 96 hours at 10$^{\circ}C$, and there was a significant difference according to Gukhwa content (p＜.05). Springiness remained unchanged after storing, 24 hours at 30$^{\circ}C$. Cohesiveness was high in every group of P1, P3 and P5, in which Gukhwa powder was added, right after being made, but as temperature rose and time passed, it heightened in group F3, in which 3% of Gukhwa flower was added. In all the samples, hardness gradually increased as the storing time at each temperature passed, and decreased as Gukhwa content increased. Chewiness was getting high as the storing time passed and temperature lowered. Color in sensory evaluation and the value of lightness in mechanical measurement showed a positive correlation at storing temperature 4$^{\circ}C$ and 10$^{\circ}C$ (p<.01). Softness and the value of lightness showed a negative correlation (p<.05). In sensory evaluation, softness and moisture showed a negative correlation with the value of lightness when storing at 30$^{\circ}C$.

• Applied Biological Chemistry
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• v.34 no.2
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• pp.149-153
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• 1991

Several commercial soybean oils were stored at $20^{\circ}C,\;40^{\circ}C$ and $60^{\circ}C$ with daily exposure of fluorescent light for 12 hours and evaluated their rancidity by headspace gas chromatographic analysis of pentanal and hexanal. The data of gas chromatographic analysis was compared with organoleptic flavor evaluation. For headspace gas chromatographic analysis, the volatile compounds were recovered by porous polymer trap and flushed into a fused silica capillary column at $250^{\circ}C$, The pentanal and hexanal separated were identified by gas chromatography and gas chromatography-mass spectrometric method. The results showed that the contents of pentanal and hexanal were linearly increased during storage for 100 days. A very simple linear relationship was found between organoleptic flavor scores and amounts of two volatile compounds with very high correlation coefficient. A similar linear relationship was also obtained for acid and peroxide value with sensory data. This results suggested the possible implication of pentanal and hexanal as an quality index for rancidity evaluation of soybean oil.

• Analytical Science and Technology
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• v.10 no.6
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• pp.439-444
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• 1997

Twelve kinds (1set) standard materials of chemical ingredients of lead zirconate titanate[$Pb(ZrTi)O_3$] have been developed in order to determine fast and accurate measurement of X-ray fluorescence spectrometry. Especially, we used diluted(ahout sixteen times) filling compound($Li_2B_4O_7/LiBO_2=4/1$) to consider removal effect of matrix, storage convenience, and homogenous characteristics. As a result from the four different laboratories, we obtained extremly good agreement about the standard curve on twelve standard materials which containing eleven elements, PbO, $ZrO_2$, $TiO_2$, SrO, $WO_3$, $La_2O_3$, $Cr_2O_3$, MgO, $Nb_2O_5$, and $MnO_2$. The correlation factor of standard curve was over 0.998. However, ZnO has relatively low correlation factor, 0.977, because the concentration was 10ppm lower than other original materials. This analysis reveals that ZnO has shown the poor linearity as well as low fluorescence intensity. In present work, XRF standard materials are useful for determining a rapid and accurate results for major and minor elements concentration among PZT.

• Applied Chemistry for Engineering
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• v.19 no.5
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• pp.526-532
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• 2008

The proposed $CO_2$ storage technology in the present study is a one-step sequestration process that stabilizes $CO_2$ in a reactor with Serpentine. The advantage of this technology is associated with its high stability of final product so that the entire system is recognized as permanent environment-friendly $CO_2$ removal method. Since the sequestration reaction mechanisms are generally understood that carbonation reaction proceeds with very slow rate, so that pretreatment method to increases reaction rate of $CO_2$ carbonation reaction should be developed. To increase the reactivity of Serpentine with $CO_2$, two different methods of pretreatment are carried out in the present investigation. One is heat-treatment, the other is chemical pretreatment. In this study, only chemical pretreatment is considered leaching method of magnesium from Serpentine using sulfuric acid at the various reaction temperatures, times, and acid concentrations. Experimental results illustrated that pretreatment by sulfuric acid increases surface area of serpentine from $11.1209m^2/g$ to $98.7903m^2/g$ and extracts magnesium compounds. Single variable experiment demonstrated the enhancements of magnesium extraction with increased reaction temperature and time. Amount of magnesium extraction is obtained by using the data of ICP-AES as maximum extraction condition of magnesium is 2 M acid solution, $75^{\circ}C$ and 1hr. After performing chemical pretreatment, carbonation yield increased from 23.24% to 46.30% of weight.

• Korean Journal of Food Science and Technology
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• v.46 no.6
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• pp.689-693
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• 2014

Flounder sikhe is one of the traditional Korean fermented foods. Because honey, fucoidan, propolis, aronia berry, and horseradish are well known to have natural antimicrobial properties, we investigated their antimicrobial effects on improving the quality of flounder sikhe. Ethanol extracts of propolis inhibited the growth of Bacillus cereus, Staphylococcus aureus, and Listeria monocytogenes. The extracts of aronia berry showed similar effects against Salmonella Typhimurium. We also assessed the total polyphenol and total flavonoid content and 2,2-diphenyl-2-picrythydrazyl (DPPH) radical scavenging activity in the extracts obtained from these natural materials. The contents of polyphenols and flavonoids were the highest in propolis, which also showed a high DPPH radical scavenging activity. Therefore, addition of propolis 0.5% to flounder sikhe showed optimal improvement, with a storage stability of 15 days at pH 5.39, volatile basic nitrogen (VBN) content at 24.73 mg/100 g, and total bacterial count at $1.81{\times}10$ colony forming unit (CFU)/g.