• Journal of the Korean earth science society
• /
• v.18 no.6
• /
• pp.515-521
• /
• 1997

To investigate the nature of the waste materials in the Nanjido Landfill, we have conducted multivariate statistical analysis of geophysical data set comprised of magnetic, gravity, LandSat TM thermal band and surface depression measurement data. Because these data sets show different responses to the depth, we have transformed the observed total field magnetic data and gravity data to the residual reduced-to-pole(RTP) magnetic anomalies and the three dimensional density anomalies, respectively, and utilized the informations about the upper shallow part of the landfills only in the following process. For the statistical analysis at the points of depression measurement, the magnetic, density and LandSat data values at these points are determined by interpolation process. Since the multivarite statistical analysis technique utilizes a clustering algorithm for classification of data set and we have measured the dissimilarity between objects by using Euclidean distance, standardization was applied prior to distance calculation in order to eliminate any scaling effects due to different measurement unit of each data set. The hierarchial grouping technique was used to construct the dendrogram. The optimum number of statistical groups(clusters), which are classified on the basis of geophysical and geotechnical characteristics, appeared to be six on the resulting dendrogram. The result of this study suggests that the dimension and nature of the multicomponent waste landfills can be identified by application of the multivarite statistical analysis technique to integrated geophysical data sets.

• Culinary science and hospitality research
• /
• v.17 no.4
• /
• pp.39-58
• /
• 2011

This study aimed to investigate recognition and satisfaction toward Korean herbal foods according to dietary lifestyle as well as the actual status of using ingredients for Korean herbal foods while looking for methods to improve use. The general characteristics of the respondents included relations with foods such as learning or working on them, and the correlations with the examined items were analyzed by grouping according to dietary lifestyle. Five significant dietary lifestyle groups were derived by analyzing the groups using the factor scores from the analysis. Recognition of Korean herbal foods was higher with older respondents and more cooking experience. Regarding experience related to Korean herbal foods, the housewives showed higher satisfaction when the ingredients of foods were bought and cooked. And satisfaction with price differed significantly by dietary lifestyle. With regard to experience of using ready-to-cook or ready-to-eat products, the groups with more cooking experience indicated relatively lower satisfaction with the taste of such products. When visiting restaurants, the groups with less cooking experience showed higher satisfaction with taste and nutritional values. Regarding the actual status of using ingredients for Korean herbal foods, most of the respondents answered that hygiene and quality management, distribution and marketing, and the promotion of ingredients are all essential.

• Journal of Mushroom
• /
• v.2 no.2
• /
• pp.49-59
• /
• 2004

To establish a genetic relationships of collected Ganoderma strains, mycelium growth according to media and temperature, colony morphology, chlamydospore formation and fruitbody morphology were investigated. For the identification of optimal growth conditions of the strains, five different growth media and four different temperature were tested. GCM (Ganoderma complete medium) at $30^{\circ}C$ was the most effective for mycelial growth of 68 strains with more or less variation. The strains were divided into 28 groups based on their colony shapes, and most of them belong to CM3 or CM8 group. Chlamydospores were observed in the mycelia of 16 strains including ASI 7022 on microscope, but not in most G. lucidum domestic strains, which showed relatively lagging growth on $35^{\circ}C$ in mycelial growth experiment. These results were not similar to those of G. lucidum but those of G. tsugae imported from USA. The strains were cultivated on oak sawdust media to see their fruit body formation. Ninety-seven among 115 strains formed fruitbodies in sawdust cultivation. They showed two forms of fruitbodies, 89.7% of flat type or 10.3% of antler type, although these shapes can be affected by $CO_2$ concentrations. These results suggest that the native strains formerly considered to belong to G. lucidum have to be re-classified with further study.

• The Journal of the Korea Contents Association
• /
• v.12 no.12
• /
• pp.489-498
• /
• 2012

This paper consists of two parts: In the first part, we describe our work to build hierarchical knowledge base of digital library patron's research interests and learning topics in various scholarly areas through analyzing well classified Electronic Theses and Dissertations (ETDs) of NDLTD Union catalog. Journal articles from ACM Transactions and conference web sites of computing areas also are added in the analysis to specialize computing fields. This hierarchical knowledge base would be a useful tool for many social computing and information service applications, such as personalization, recommender system, text mining, technology opportunity mining, information visualization, and so on. In the second part, we compare four grouping algorithms to select best one for our data mining researches by testing each one with the hierarchical knowledge base we described in the first part. From these two studies, we intent to show traditional verification methods for social community miming researches, based on interviewing and answering questionnaires, which are expensive, slow, and privacy threatening, can be replaced with systematic, consistent, fast, and privacy protecting methods by using our suggested hierarchical knowledge base.

• Journal of Life Science
• /
• v.27 no.3
• /
• pp.351-354
• /
• 2017

Cowpea (Vigna unguiculata (L.) Walp.) is recognized as a potential source of protein and other nutrients. The genus Vigna includes 100 wild species of plants. Especially, Vigna unguiculata includes annual cowpeas (ssp. unguiculata) and ten wild perennial subspecies. DNA sequence of internal transcribed spacer (ITS) region was determined for Vigna sinensis, one of native plant, which was found in recent but thought to have gone extinct in Korea. The seeds of Vigna sinensis used in this study were donated from Dong-Young Jo. The DNA sequence of ITS-5.8S-ITS2 for Vigna sinensis obtained from this study was deposited as Vigna sinensis AY195581 on GenBank of NCBI (National Center for Biotechnology Information). We investigated the sequence-based phylogenetic relationships of plants related and clarified its taxonomical position. DNA similarities among subspecies including Vigna unguiculata showed the range 98 to 100% in sequence-based phylogenetic analysis using total 507 base pairs of ITS1, 5.8S and ITS2. Vigna unguiculata and subspecies were grouped independently as one cluster from other Vigna species used in the phylogenetic analysis. In this study, based on the phylogenetic analysis using the ITS1-5.8S-ITS2 sequence of Vigna sinensis, it may be concluded to be classified to one of Vigna unguiculata substrains.

• Molecules and Cells
• /
• v.26 no.6
• /
• pp.566-575
• /
• 2008

Twenty-five chipmunk species occur in the world, of which only the Siberian chipmunk, Tamias sibiricus, inhabits Asia. To investigate mitochondrial cytochrome b sequence variations and population structure of the Siberian chipmunk in northeastern Asia, we examined mitochondrial cytochrome b sequences (1140 bp) from 3 countries. Analyses of 41 individuals from South Korea and 33 individuals from Russia and northeast China resulted in 37 haplotypes and 27 haplotypes, respectively. There were no shared haplotypes between South Korea and Russia - northeast China. Phylogenetic trees and network analysis showed 2 major maternal lineages for haplotypes, referred to as the S and R lineages. Haplotype grouping in each cluster was nearly coincident with its geographic affinity. In particular, 3 distinct groups were found that mostly clustered in the northern, central and southern parts of South Korea. Nucleotide diversity of the S lineage was twice that of lineage R. The divergence between S and R lineages was estimated to be 2.98-0.98 Myr. During the ice age, there may have been at least 2 refuges in South Korea and Russia - northeast China. The sequence variation between the S and R lineages was 11.3% (K2P), which is indicative of specific recognition in rodents. These results suggest that T. sibiricus from South Korea could be considered a separate species. However, additional information, such as details of distribution, nuclear genes data or morphology, is required to strengthen this hypothesis.

• Information Systems Review
• /
• v.9 no.2
• /
• pp.15-39
• /
• 2007

Mobile games have emerged as the most innovative entertainment technology, adding new revenue streams, taking advantage of the potential of wireless applications and service offerings. Mobile games, like any other types of computer game, offer a unique value for users in providing an exciting digital experience in virtual worlds. In this paper, we attempt to investigate the demographic factors which play critical roles in determining the level of playing times; classify mobile gamers based on their motives for playing games; and empirically test differences in their demographic factors and mobile game usage. Statistical results show that significant differences in playing times exist, depending upon their age, gender, mobile device, mobile phone usage, mobile game experiences, and preferred games genres. Applying Factor analysis, we have identified Escape, Social interaction, Challenge and Competition, Fantasy, Diversion and Relaxation, Ease of Accessibility as key motivators for playing mobile games. Additional cluster analysis shows that the categorization of gamers, according to their usage habits and the key motivators for playing, can be made as follows: Multi-gamers, Communication-focused gamers and Mobile active-gamers. Further correlation of these grouping with socio-economic data shows the significant differences in gaming habits and patterns of mobile phone use.

• Asian Journal of Turfgrass Science
• /
• v.25 no.2
• /
• pp.171-176
• /
• 2011

Sclerotinia homoeocarpa, the causal agent of dollar spot, is one of the most common pathogens of cool season turfgrasses in South Korea. The vegetative compatibility group (VCG) assay was carried out using nitrate-nonutilizing (nit) mutants recovered from 13 South Korean isolates with various geographical origins. The mutants were divided into four phenotypic classes based on mutation loci associated with nitrogen assimilation: nit1, nit2, nit3, and NitM. The recovered number of nit mutants greatly varied among the isolates, ranging from 0 to 15 mutants. Of the mutants isolated, nit1 and nit2 mutants were most common (80%) while NitM and nit3 were relatively rare. One dominant and four minor VCGs were determined from 18 mutant isolates tested. To study population structures of Korean S. homoeocarpa isolates and increase our understanding of its ecological and epidemiological aspects for dollar spot management on turfgrass, more generated mutants should be tested with more diverse isolate collections.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.43 no.3 s.345
• /
• pp.1-9
• /
• 2006

In this paper, we propose a MIMO-OFDMA (Multi Input Multi Output-Orthogonal Frequency Division Multiple Access) system based on beamforming for performance improvement of downlink real-time traffic transmission in harsh channel conditions with low CIR (Carrier-to-Interference Ratio). In the proposed system, we first consider the M-GTA-SBA (Modified-Grouped Transmit Antenna-Simple Bit Allocation) using effective CSI (Channel State Information) calculation procedure based on spatial resource grouping, which is adequate for the combination of MRT (Maximum Ratio Transmission) in the transmitter and MRC (Maximum Ratio Combining) in the receiver. In addition, to reduce feedback information for the beamforming, we also apply QEGT (Quantized Equal Gain Transmission) based on quantization of amplitudes and phases of beam weights. Furthermore, considering multi-user environments, we propose the P-SRA (Proposed-Simple Resource Allocation) algorithm for fair and efficient resource allocation. Simulation results reveal that the proposed MIMO-OFDMA system achieves significant improvement of spectral efficiency in low CRI region as compared to a typical open-loop MIMO-OFDMA system using pseudo-orthogonal space time block code and H-ARQ IR (Hybrid-Automatic Repeat Request Incremental Redundancy).

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.47 no.1
• /
• pp.62-72
• /
• 2010

PM OLED is used in many applications as one of the display for the next generation. The most essential problems are the power dissipation and the short life time in applying PM OLED into a commercial application. Many efforts are made in developing the panel and in improving the circuit for expanding the current market wider. The life time in PM OLED is expanded by lessening the power dissipation of the circuit for the magnitude of the driving current is lowered. It is possible to minimize the power dissipation from improving the driving technology. The classical technology, Row-to-Row driving, is that row is selected one by one while applying the column current input individually. The multi-line driving is a new technology which is to select multiple rows simultaneously while applying the column current as a whole. However, the solution of the multi-line driving is NP-complete problem. The efficiency is dependant on the sort of picture and the driving condition. This paper presents the new efficient multi-line driving which is that the multiple lines are selected by applying column current together after grouping the simultaneous driving group applying the gnew efficient muthe coi-line dr coefficient. Bengrouping the several rows which has the higher coi-line dr coefficient, the more efficient driving is realized to present the high quality image and to lessen the power dissipation and to stretch the life time in the PM OLED.