• Journal of Wetlands Research
• /
• v.13 no.1
• /
• pp.1-11
• /
• 2011

A chronic drought stress has been imposed during non-rainy season(from winter to spring) since 1990s. We faced the most significant water crisis in 2001, and the drought was characterized by sultry weather and severe drought on a national scale. It has been widely acknowledged that the drought related damage is 2-3 times serious than floods. In the list of the world's largest natural disaster compiled by NOAA, 4 of the top 5 disasters are droughts. And according to the analysis from the NDMC report, the drought has the highest annual average damage among all the disasters. There was a very serious impact on the economic such as rising consumer price during the 2001 spring drought in Korea. There has been flood prevention measures implemented at national-level but for mitigation of droughts, there are only plans aimed at emergency (short-term) restoration rather than the comprehensive preventive measures. In addition, there is a lack of a clear set of indicators to express drought situation objectively, and therefore it is important and urgent to begin a systematic study. In this study, a nonstationary downscaling model using RCM based climate change scenario was first applied to simulate precipitation, and the simulated precipitation data was used to derive Standardized Precipitation Index (SPI). The SPI under climate change was used to evaluate the spatio-temporal variability of drought through principal component analysis at three different time scales which are 2015, 2045 and 2075. It was found that spatio-temporal variability is likely to modulate with climate change.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.5A
• /
• pp.717-725
• /
• 2000

Within the last several years, there has been a large number of algorithms developed for face recognition. The majority of these algorithms have been view- and projection-based algorithms. Our definition of projection is not restricted to projecting the image onto an orthogonal basis the definition is expansive and includes a general class of linear transformation of the image pixel values. The class includes correlation, principal component analysis, clustering, gray scale projection, and matching pursuit filters. In this paper, we perform a detailed analysis of this class of algorithms by evaluating them on the FERET database of facial images. In our experiments, a projection-based algorithms consists of three steps. The first step is done off-line and determines the new basis for the images. The bases is either set by the algorithm designer or is learned from a training set. The last two steps are on-line and perform the recognition. The second step projects an image onto the new basis and the third step recognizes a face in an with a nearest neighbor classifier. The classification is performed in the projection space. Most evaluation methods report algorithm performance on a single gallery. This does not fully capture algorithm performance. In our study, we construct set of independent galleries. This allows us to see how individual algorithm performance varies over different galleries. In addition, we report on the relative performance of the algorithms over the different galleries.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.6
• /
• pp.761-767
• /
• 2006

To determine freshness and quality change of chicken products during storage, we manufactured freshness indicator and monitored the surface pH, volatile basic nitrogen (VBN), thiobarbituric acid reacted substance (TBARS), total bacterial counts, electronic nose analysis, and sensory evaluation. All chicken products (drum, wing, thigh) had a change in color of freshness indicator after storage of 3 days at $4^{\circ}C$, indicating poor quality at the time. VBN, TBARS values, and total bacterial counts reached the decay point at the time of color change of freshness indicator attached to the surface of chicken samples. The sensory evaluation also indicated sample was not acceptable by off-odor at day 4 of storage. According to electronic nose analysis to examine off-odor, there were significant differences in terms of principal component analysis values among chicken samples of day 0, day 3, and day 5 of storage. These results suggest that freshness indicator should be useful in determining expiration date of chicken products during marketing by indicating the microbial safety as well as physicochemical and sensory change.

• Journal of Conservation Science
• /
• v.25 no.3
• /
• pp.335-345
• /
• 2009

This paper presents investigations on 60 glass beads excavated from floorless tombs of Eunpyeong Newtown site to figure out composition and lead isotope ratio by SEM-EDS and TIMS, which show the difference between their compositions and Pb provenance of lead glass. The results of the composition analysis are that excavated glass are mainly divided into Potash glass($K_2O$-CaO-$SiO_2$) and Potash-lead glass($K_2O$-PbO-$SiO_2$) and the samples excavated from III-3 floorless tombs No.1005 are presumed not glass but Quartz. The transparent 9 lead glasses excavated from II-3 floorless tomb No.101 and III-3 floorless tomb No.908 seem to be manufactured by the same raw material at same site because the concentration of their compositions are well accorded with each other and deviations of them are very limited. As a result of principal component analysis(PCA), glass beads excavated are largely assort to two groups, Potash glass and Potash lead glass as well. That is, glass beads excavated from Eunpyeoung Newtown sites are quite different two types of main composition. In addition, the results of Pb provenance analysis used in lead glass confirm that most lead glass are significantly correlated with galena of northern China.

• Culinary science and hospitality research
• /
• v.18 no.4
• /
• pp.59-69
• /
• 2012

This study examines the role of mathematics anxiety as a mediator between self efficacy and mathematics skills using a series of regression analyses suggested by Baron RM & Kenny DA(1986). The participants include college students who enrolled in the Food Service Production and Operation course in a department of hotel and restaurant management at a college in the United States. Descriptive analysis, principal component analysis, reliability test, and a series of regression analyses were used for data analysis using SPSS 19.0. In order to collect data for the study, General Self Efficacy Scale(GSES) and Math Anxiety Rating Scale(MARS) were utilized, and they turned out to be reliable(${\alpha}$=.906 and ${\alpha}$=.890, respectively). A significant negative relationship was found between self efficacy and mathematics anxiety. In addition, it was found that self-efficacious students performed better mathematics skills than those who had lower level of self efficacy. However, the relationship was no longer significant when the concept of mathematics anxiety was added, which satisfies the condition of mediation.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.35 no.4
• /
• pp.431-437
• /
• 2002

In order to understand the spatiotemporal variation of water quality, an investigation on variation characteristics of water quality was conducted at 13 stations in Yongil bay from 1990 to 1998. The salinity in summer was relatively lower than that in other seasons and it have increased from inner bay to outside of the bay gradually. However, nitrate concentration in summer was relatively higher than that in other seasons, and it was the highest, up to $65.40\%$, among dissolved inorganic nitrogens, Nitrate concentration indicates the possibility of affecting by freshwater discharges to Yongil bay. Correlation analysis showed that salinity had a significantly good correlation with nitrate. This result suggested that inflow of river had an influence on increase of nitrate. The result of Principal Component Analysis (PCA) indicated that nitrate was major factor to influence the water quality in Yongil Bay.

• Korean Journal of Plant Resources
• /
• v.18 no.2
• /
• pp.260-269
• /
• 2005

Taxonomic studies on morphological, principal component analysis (PCA), palynological, RAPD and PCR-RELP analysis were conducted to intraspecific relationships of Rubus oldhami. Three types of Rubus oldhami based on the flower characters such as petal length and number were used in this study. Among the 14 morphological characters, perianth length, calyx lobe length, apical leaflet shape and leaflet length were used to distinguish for each type. The pollen characters such as shape, aperture number, surface sculpture were showed very similar among three types. Eight primers out of 20 arbitrary primers were screened for three types, and were revealed 33 ($60\%$) polymorphic bands. The phonogram by RAPD data showed incongruent with morphological analysis. Even though ten restriction endonucleases produced 20 restriction sites, polymorphic bands were not observed. Based on the results, three types of Rubus oldhami divided well by morphological characters, but pollen and DNA data were not supported. Therefore, type 1 and 2 which different from type 3 by flower characters considered as a temporary hybrid or ecotype because of their similar habitats.

• Korea Journal of Hospital Management
• /
• v.17 no.1
• /
• pp.1-22
• /
• 2012

This study tires to examine affects that job and socio-psychological stresses of female office workers influence job satisfaction, organization commitment, and leaving intentions. A complete data are collected by conducting a survey with 240 female office workers from 9 medical institutions regarded as almost general hospital in Seoul. It is analyzed that the relation between socio-psychological stress and job satisfaction, organization commitment, and leaving intentions by using t-test; analysis of variance; correlation analysis; principal component analysis; linear structural equation modeling; etc. The results of this study are summarized as following. First, as it was comprehended by specific characteristics of subjects that the female office workers' level of job and socio-psychological stress, job satisfaction, organizational commitment, and leaving intention, there were statistically significant distinctions from their age, marital status, presence of children, position in the organization, type of employment, and monthly average income. Second, this study regarded relationship between the female office workers' level of job and socio-psychological stresses, job satisfaction, organizational commitment, and leaving intention. Job and socio-psychological stresses were negatively correlated with job satisfaction and organizational commitment, but the stresses were positive with leaving intention. Third, after evaluating effect that 8 features related to the job stress could influence job stress, the most effective valuables were in order to unfairness in organizational structure, workplace culture, inadequate compensation, and relationship conflict. Fourth, when looking at the overall effects of the job and sociopsychological stresses on job satisfaction, organizational commitment, and leaving intention, work autonomy was the most influencing factor of work stress levels. The level of the job stress seemed to be a prevalent impact on the leaving intention and it showed the most negative relationship that path coefficient from leaving intention to organizational commitment and also from organizational commitment to job satisfaction. Based on these findings, it can be defined that the job and socio-psychological stresses strongly influence job satisfaction, organizational commitment, and leaving intention.

• Korean Journal of Soil Science and Fertilizer
• /
• v.41 no.2
• /
• pp.118-125
• /
• 2008

Diverse organic amendments available in local areas have been used to improve soil quality in red pepper field and so the need for investigating the soil chemical and biological properties changed by the organic amendments application is increasing. Soil microbial diversities were measured by phospholipid fatty acid (PLFA) and Biolog $EcoPlate^{TM}$. Compost was most effective for improving soil chemical properties including pH, EC, total nitrogen, P, K, and Ca, and bark increased soil organic matter significantly (P=0.05). Compost increased the fatty acids indicating actinomycetes and vascular arbuscular fungi, and ratio of cy19:0/18:1w7c and monounsaturated fatty acids/saturated fatty acids in soils in PLFA analysis. Bark increased soil fungal indicators in PLFA analysis (P=0.05). Principal component analysis of Biolog EcoPlate data and PLFA differentiated the compost- and bark-amended soils from other organic matteramended soils especially the soil incorporated with compost. More researches are needed to use bark for improving soil microbial properties because the soil chemical and microbiological properties caused by compost and bark are significantly different.

• Korean Journal of Food Science and Technology
• /
• v.40 no.2
• /
• pp.160-165
• /
• 2008

This study was conducted to analyze sensory profiles of commercial sojues using a standardized sensory evaluation procedure, and to investigate the effects of sensory characteristics and brands on consumer liking for soju. Descriptive analysis and consumer taste testing were conducted for seven commercial sojues. For the descriptive analysis, eight panelists generated and evaluated 12 flavor and one pain-sensation attributes for the soju, and there were significant differences among the soju samples for all the 13 sensory attributes. For the descriptive data, principal component analysis was performed to summarize the sensory characteristics of the sojues. For the consumer testing, 224 soju drinkers (20-29 year-olds) were recruited and randomly divided into two groups; a blind group and a group with the knowledge of brand. While the hedonic ratings obtained from the blind group didn't indicate significant differences among the sojues, the ratings obtained from the brand-informed group showed significant differences. Finally, the individual preferences of the 112 consumers in each group were investigated by preference mapping techniques.