• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.3
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• pp.428-451
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• 2010

Traffic matrix-based anomaly detection and DDoS attacks detection in networks are research focus in the network security and traffic measurement community. In this paper, firstly, a new type of unidirectional flow called IF flow is proposed. Merits and features of IF flows are analyzed in detail and then two efficient methods are introduced in our DDoS attacks detection and evaluation scheme. The first method uses residual variance ratio to detect DDoS attacks after Recursive Least Square (RLS) filter is applied to predict IF flows. The second method uses generalized likelihood ratio (GLR) statistical test to detect DDoS attacks after a Kalman filter is applied to estimate IF flows. Based on the two complementary methods, an evaluation formula is proposed to assess the seriousness of current DDoS attacks on router ports. Furthermore, the sensitivity of three types of traffic (IF flow, input link and output link) to DDoS attacks is analyzed and compared. Experiments show that IF flow has more power to expose anomaly than the other two types of traffic. Finally, two proposed methods are compared in terms of detection rate, processing speed, etc., and also compared in detail with Principal Component Analysis (PCA) and Cumulative Sum (CUSUM) methods. The results demonstrate that adaptive filter methods have higher detection rate, lower false alarm rate and smaller detection lag time.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1217-1223
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• 2007

I investigated the reproduction system of nine natural populations of P. discolor in Korea and two Mongolian P. conferta populations. The measurements of 19 quantitative or qualitative morphological characters were taken on each of total individuals directly from their natural habitats. Multivariate principal component analyses (PCA) were conducted to detect differences among populations consid-ering several characters simultaneously of variances using the statistical analysis system. 19 morpho-logical characteristics between Korean Potentilla species and Mongolian Potentilla species showed a slight heterogeneity of variance. The length of internodes (LFL and LSI) and characteristics of root (LLR and NOR) were shown a significant difference between two species (P<0.05). The number of ra-mets in P. conferta decreased with increasing geographic distance from viviparity. However, P. discolor has most ramets at distance intervals $60{\sim}80$ cm. In light conditions, P. discolor was significantly less resilience than P. conferta. In drought conditions, although there was not shown significant difference, P. conferta was less resilience than P. discolor. The core analysis indicates that P. conferta is the more resistant species than P. discolor and usually propagates by clonal growth during several strong envi-ronmental disadvantages such as drought events.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1286-1286
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• 2001

Despite extensive theoretical and experimental studies the structure of the protein-solvent interface is subject of many controversy. Understanding the processes that occur in aqueous solution requires understanding of the solvent influence on the structure of protein. The aim of this study is to investigate the applicability of NIR methods in the study of hydration phenomena in protein solutions. Temperature-induced changes in NIR spectra of -lactoglobulin (BLG) in aqueous solutions have been investigated by means of two-dimensional correlation spectroscopy (2DCOS) and principal component analysis (PCA). With the temperature increase the balance of forces between the BLG's interaction with itself and the BLGs interaction with its environment is disrupted leading to BLG unfolding. Significant differences of 2D signals and distinct discrepancies of loading on PC1 and PC2 were observed as a result of temperature increase. In the native folded conformation of BLC, most of the nonpolar amino acids are hidden in the centre of the structure, out of contact with water molecules, while charged groups are outside, in the contact with water. The polar groups promote low density Ih-type structure in the water outside this first hydration shell. When BLG unfolds it assumes a more extended configuration on which the previously buried nonpolar groups are exposed to water and promote the higher density II-type structure outside its first shell. Detailed assignments of bands attributed to the bulk water, different states of the hydrated water and the changed conformation of BLG are proposed.

• Journal of the Korean Institute of Gas
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• v.7 no.3 s.20
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• pp.24-31
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• 2003

To operate process plant safely and economically, process monitoring is very important. There are a great number of data acquired through distributed control system and process information system. Fault monitoring is the task with difficulties owing to not only the huge amount of data, but also nonlinearity of chemical processes. In this research, the program, REFA, based on PCA and functional link associative neural network has developed. REFA has better learning capabilities, generalization abilities, and shorter learning time than existing neural network programs. In this work its usefulness has proven by application to Tennessee Eastman process.

• Korean Institute of Interior Design Journal
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• v.19 no.5
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• pp.182-189
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• 2010

An exhibition administrator, one who works in the exhibition space of museums and exhibition halls, has carried on various tasks in order to improve the exhibition standard and viewer's satisfaction. Although exhibition administrators have a variety of direct perceptions regarding an exhibition in the actual on-site space, a study on their consciousness was absent. Thus, this study was to comprehend the awareness of how the consciousness of exhibition administrators, who directly understand the various matters regarding the exhibition on-site, was structured and to investigate the difference between the consciousness of exhibition viewers and designers. For the study, Q-Methodology, which can scientifically manage the consciousness such as awareness and the acquired attitudes through individual experiences from a specific group, was applied. The classification of 33 Q-methodology research questions was carried out with 18 exhibition administrators, who are working at either national or public museums and exhibition halls in Korea, and the Principal Component Analysis (PCA) using the QUANL PC program was performed. The results of the analysis provided the following 4 types: 'viewer attraction and exhibition method oriented', 'exhibition standard oriented', 'public relations oriented' and 'the public and government's interest oriented'. Each type showed significant characteristics. Additionally, n showed that 'exhibition standard oriented' was the common type after comparing the type of consciousness among the 3 groups of people, such as an exhibition administrator, an exhibition designer, and a viewer. It indicated that the types of 'public relations oriented' and 'the public and government's interest oriented' from the consciousness category for the exhibition administrator were the most independent type, not being found in any of the other groups. And the Significant correlation between the exhibition viewers and designers was identified after examining the Pearson's correlation among the 3 groups.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.55.5-56
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• 2016

Turbulence plays an important role in molecular clouds. However, the properties of turbulence are poorly understood. In order to study the influence of turbulence in molecular clouds, we need to sample the turbulent properties in the full range of scales down to sonic scale. We mapped the $20^{\prime}{\times}60^{\prime}$ area covering the Orion Molecular Cloud (OMC) 1-4 region in HCN 1-0 and HCO+ 1-0 with Taeduk Radio Astronomy Observatory (TRAO) 14-m telescope as part of the TRAO key science program, "Mapping turbulent properties of star-forming molecular clouds down to the sonic scale (PI: Jeong-Eun Lee)". In addition, we combine our TRAO data with other molecular line maps ($^{13}CO$ 1-0, $C^{18}O$ 1-0, CS 1-0, $N_2H^+$ 1-0) obtained with the Nobeyama Radio Observatory (NRO) 45-m telescope. To analyze these data, we apply statistical methods, the principal component analysis (PCA) and spectral correlation function (SCF), which are known to be useful to study underlying turbulent properties and to quantitatively characterize cloud structure. We will present the preliminary results of observations and analyses.

• Molecular & Cellular Toxicology
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• v.2 no.3
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• pp.185-192
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• 2006

To elucidate the molecular mechanisms associated with early renal injury induced by gentamicin, the most commonly used antibiotics worldwide in the treatment of Gram-negative bacterial infections. We have identified genes differentially expressed at different duration of gentamicin administration. C57BL/6 female mice were treated daily with gentamicin (20 mg/kg, 100 mg/kg, and 200mg/kg) for 7 days and then sacrificed at day 1, 3, and 7 after administration. Standard blood biochemistry and histopathological observation indicative of nephrotoxicity were made. Total RNA was extracted from the kidney for microarray analysis using Affymetrix $GeneChip^{\circledR}$. Five hundred and seventy eight genes were identified as being either up-or down-regulated over 2-fold changes during early renal injury (p<0.05) and were analyzed by hierarchical clustering. The results showed that the genes involved in early immune responses were differentially regulated during early renal injury. Principal component analysis (PCA) confirmed sample separation according to the degree of renal toxicity. In addition, we identified two potential biomarkers that may predict early renal toxicity. This data may contribute to elucidate of the genetic events during early renal injury and to discover the potential biomarkers for nephrotoxicity induced by gentamicin.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.363-381
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• 2020

The polymetallic Co, Ni, Cu, As, Au, and Ag deposits of Bou Azzer East are located in the western part of the Bou Azzer inlier in the Central Anti Atlas, Morocco. Six stages of emplacement of the mineralization have been identified. Precious metals (native gold and electrum) are present in all stages of this deposit except the early nickeliferous stage. From the Statistical analysis of the Co, As, Ni, Au, and Ag contents of a set of 501 samples, shows that the Pearson correlation coefficient between As-Co elements (0.966) is the highest followed by that of the Au-Ag couple (0.506). Principal component analysis (PCA) and hierarchical ascending classification (HAC) of the grades show, that Ni is associated with the pair (As-Co) and Cu is rather related to the pair (Au-Ag). The kriging maps show that the highest values of the Co, As and Ni appear in the contact of the serpentinite with other facies, as for those of Au and Ag, in addition to anomalous zones concordant with those of Co, Ni and As, they show anomalies at the extreme South and North of the study area. The development of the anomalous Au and Ag zones is mainly along the N40-50°E and N145°E directions.

• Journal of the Korean Society of Food Culture
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• v.32 no.2
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• pp.150-161
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• 2017

This study was conducted to identify sensory characteristics of soy-meat samples by trained panels and to observe the relationship between these sensory characteristics and consumer acceptability of the samples. Descriptive analysis was performed on eight samples; four types of patty style soy-meat samples (Soy-meat Patty; SP) made with a Ddukgalbi recipe (YSP, VSP, LSP, and SSP) and four types of Bulgogi style soy-meat samples (Soy-meat Bulgogi; SB) made with a Bulgogi recipe (YSB, VSB, LSB, and SSB). Seven panelists were trained, and they evaluated the appearance, odor/aroma, flavor/taste, texture/mouth feel, and after taste attributes of these samples. Forty attributes were generated by panelists, and 37 attributes were significantly different across products (p<0.05). The SB group was characterized by beef, leek, and garlic flavor as well a sweetness, denseness, slipperiness, chewiness, and pepper after taste. The SP group was characterized by roughness, particle size, rancid oil flavor, raw bean flavor, astringent, sourness, and adhesiveness. Consumer test (n=125) showed that the VSB sample had the highest scores for acceptability of appearance, flavor, texture, and overall liking. The PLSR results show that the attributes that were more positively associated with acceptance of soy-meat samples were beef taste, wetness, and chewiness, whereas the raw bean smell and rancid oil flavor attributes were negative.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.6
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• pp.836-850
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• 2012

This study was conducted to identify the sensory characteristics of the Korean traditional confectionery, dasik, prepared under different conditions and to compare their consumer acceptance in Korea. To accomplish this, descriptive analysis of eight samples prepared using two types of rice cake powder, dasik (Rflour, Rflour_Omija), brown rice powder red ginseng dasik (Brice_Ginseng_P), pinepollen dasik (PineP), black sesame dasik (BSesame), bean dasik (Rbean), and two types of mungbean starch dasik (Starch_Omija, Starch_Greentea), was conducted by ten trained panelists. In addition, 81 consumers evaluated the overall acceptance (OL), acceptance of appearance (APPL), odor (ODL), flavor (FLL), and texture (TXTL) of the samples using a 9-point hedonic scale, as well as the perceived intensities of sesame flavor, sweetness, and hardness using a 9-point just-about-right (JAR) scale. Partial least square- regression (PLSR) indicated that the BSesame and Rbean samples, which had significantly (p<0.05) high roasted sesame, burnt, greasy, glossy, and cooked chestnut flavor scores, had the highest acceptability and consumer desire scores. Additionally, the PineP and Rflour_Omija samples, which had relatively high particle size, transparency, roughness, spoiled tofu, fermentation and raw rice flavor scores, were the least preferred samples. Therefore, roasted sesame, burnt, greasy, glossy, and cooked chestnut flavor attributes were considered drivers of "liking" whereas particle size, transparent, roughness, spoiled tofu, fermentation, and raw rice flavor attributes acted as drivers of "disliking" among consumers.