• Journal of Internet Computing and Services
• /
• v.16 no.1
• /
• pp.67-74
• /
• 2015

In recent years, frequent itemset mining for considering the importance of each item has been intensively studied as one of important issues in the data mining field. According to strategies utilizing the item importance, itemset mining approaches for discovering itemsets based on the item importance are classified as follows: weighted frequent itemset mining, frequent itemset mining using transactional weights, and utility itemset mining. In this paper, we perform empirical analysis with respect to frequent itemset mining algorithms based on transactional weights. The mining algorithms compute transactional weights by utilizing the weight for each item in large databases. In addition, these algorithms discover weighted frequent itemsets on the basis of the item frequency and weight of each transaction. Consequently, we can see the importance of a certain transaction through the database analysis because the weight for the transaction has higher value if it contains many items with high values. We not only analyze the advantages and disadvantages but also compare the performance of the most famous algorithms in the frequent itemset mining field based on the transactional weights. As a representative of the frequent itemset mining using transactional weights, WIS introduces the concept and strategies of transactional weights. In addition, there are various other state-of-the-art algorithms, WIT-FWIs, WIT-FWIs-MODIFY, and WIT-FWIs-DIFF, for extracting itemsets with the weight information. To efficiently conduct processes for mining weighted frequent itemsets, three algorithms use the special Lattice-like data structure, called WIT-tree. The algorithms do not need to an additional database scanning operation after the construction of WIT-tree is finished since each node of WIT-tree has item information such as item and transaction IDs. In particular, the traditional algorithms conduct a number of database scanning operations to mine weighted itemsets, whereas the algorithms based on WIT-tree solve the overhead problem that can occur in the mining processes by reading databases only one time. Additionally, the algorithms use the technique for generating each new itemset of length N+1 on the basis of two different itemsets of length N. To discover new weighted itemsets, WIT-FWIs performs the itemset combination processes by using the information of transactions that contain all the itemsets. WIT-FWIs-MODIFY has a unique feature decreasing operations for calculating the frequency of the new itemset. WIT-FWIs-DIFF utilizes a technique using the difference of two itemsets. To compare and analyze the performance of the algorithms in various environments, we use real datasets of two types (i.e., dense and sparse) in terms of the runtime and maximum memory usage. Moreover, a scalability test is conducted to evaluate the stability for each algorithm when the size of a database is changed. As a result, WIT-FWIs and WIT-FWIs-MODIFY show the best performance in the dense dataset, and in sparse dataset, WIT-FWI-DIFF has mining efficiency better than the other algorithms. Compared to the algorithms using WIT-tree, WIS based on the Apriori technique has the worst efficiency because it requires a large number of computations more than the others on average.

• Korean Journal of Soil Science and Fertilizer
• /
• v.24 no.2
• /
• pp.109-115
• /
• 1991

This study examines the effect of submergence on phosphorus adsorption characteristics in Gangseo(paddy soil), Yesan(non-cultivated soil), and Jungdong soil(upland soil). The soils were submerged with glucose sol'n at $28^{\circ}C$ for 17 days. After the submergence, the phosphorus adsorption was conducted at three temperatures(5, 25 and $45^{\circ}C$). The phosphorus adsorption maximum($X_m$) and the equilibrium constant(K) were obtained by Langmuir adsorption isotherm, and the heat of adsorption(${\Delta}H$) was calculated by van't Hoff's equiation. Results obtained are as follows ; 1. The amounts of adsorbed P were increased with temperature, but the effects of temperature on rate of P adsorption were very small in all three soils. 2. By submergence, $X_m$ were increased from 500mg P/kg to 850mg P/kg in Gangseo soil, from 1,850mg P/kg to 3,300mg P/kg in Yesan soil, and from 310mg P/kg to 670mg P/kg in Jungdong soil. But the effects of temperature on $X_m$ were very small in all three soils. 3. Submergence decreased K for Gangseo and Yesan soils, but increased for Jungdong soil. Whereas K were increased with temperature in all three soils. 4. By submergence, ${\Delta}H$ for Gangseo soil was greatly increased (from 2.2 Kcal/mole to 3.5 Kcal/mole), whereas that for Yesan soil changed little (from 5.7 Kcal/mole to 5.5 Kcal/mole). It was 4.4 Kcal/mole in submerged Jungdong soil.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.2
• /
• pp.133-140
• /
• 1999

This pot experiment was conducted to find out the forage productivity and quality in a grass/clover sward as affected by the application of three different fertilizers; double superphosphate(DS), fused Mg-phosphate(FP), and complex fertilizer(CF), on newly reclaimed hilly soil. This 1st part was concerned with the forage yields, yield components and botanical composition. The results obtained are summarized as follows: 1. The significant differences in the yields(relative yields, %) of whole forages and legume were laid in the following increasing order; CF(relative yield: 150.4% in whole forages and 169.7% in ladino clover) > FP(125.4% in whole forages and 121.7% in ladino clover) > DS(100.0%). The yield of orchardgrass was significantly reduced in the DS plot, compared with the yields in the FP and CF plots, whereas these showed no significant differences between the FP and CF plots. 2. In the botanicl composition, it showed that the rates of grass : legume were 48:52% in the DS and FP, and 40:60% in the CF. It was recognized that the application of complex fertilizer contributed to the increasing of the yields of whole forages, and especially legume yield and rate in the mixed sward.

• Korean Journal of Soil Science and Fertilizer
• /
• v.6 no.3
• /
• pp.159-163
• /
• 1973

A by-product from glutamic acid fermentation prepared by treating the fermentation residue with sulfuric acid and ammonium hydroxide was studied in the light of its chemical properties by chemical analysis and X-ray diffraction technique. Its effectiveness as fertilizer was also investigated with corn as test plant. The results are summarized as following. 1. The chemical analyses and study with X-ray diffraction technique revealed that the by-product contains an appreciable quantity of water soluble ammonium as ammonium sulfate and ammonium chloride, water soluble amino acid and in-soluble organic carbon. Particularly, the X-diffraction pattern of the material indicated the presence of unidentified water soluble double salt of ammonium sulfate and ammonium chloride. 2. The water soluble ammonium in this material was found to be as effective as urea on the growth of corn plant. 3. The organic portion of the material was found to be equally effective on the growth of corn plant as the other sources of organic matter such as compost and rice bran. It was, however found that the organic matter in the fermentation residue is more persisting in the soil than the compost and rice bran. 4. It was noticed that the application of the fermentation by-product, lowers the soil pH significantly. Inspite of the pH lowering effect, the absorption of iron by corn plant was surpressed by the application of this material.

• Tuberculosis and Respiratory Diseases
• /
• v.64 no.4
• /
• pp.278-284
• /
• 2008

Background: TRAIL is a promising anticancer agent which induces selective tumor cell death due to a unique receptor system that includes death receptors and decoy receptors. DR5 TRAIL receptor is an originally identified p53-regulated death receptor gene that was induced, by doxorubicine, only in cells with a wild-type p53 status. We investigated that focused on the correlation between the DR5 and p53 expressions in non-small cell lung cancer (NSCLC). Methods: Immunohistochemical analysis, with using avidin-biotinylated horseradish peroxidase complex, was carried out in 89 surgically resected NSCLC formalin-fixed paraffin-embedded tissue sections. As primary antibodies, we used anti-DR5 polyclonal antibody and anti-p53 monoclonal antibody. A negative control was processed with each slide. The positive tumor cells were quantified twice and these values were expressed as percentage of the total number of tumor cells, and the intensity of immunostaining was expressed. The analysis of the DR5 expression was done separately in tumor area and in a nearby region of normal tissue. Results: The DR5 expression was high in the bronchial epithelium (89% of cases) but this was almost absent in type I & II pneumocytes, lymphocytes and smooth muscle cells. High DR5 expression rate in tumor was seen in 28% (15/53) of squamous cell carcinomas, in 47% (15/32) of adenocarcinomas and, in 50% (2/4) of large cell carcinomas. The DR5 expression did not show any statistical significance relationship with the T stage, N stage, or survival. However, the DR5 expression showed significant inverse correlation with the p53 expression. (p< 0.01). Conclusion: We demonstrated that the DR5 expression in NSCLC via immunohistochemical analysis is relatively tumor-specific except for that in the normal bronchial epithelium and it is significantly dependent on the p53 status. This might be in vivo evidence for the significance of the DR5 gene as a p53 downstream gene.

• Journal of Ginseng Research
• /
• v.26 no.4
• /
• pp.191-195
• /
• 2002

In this study, we like to examine whether Panax ginseng water extract (PGWE) exerts antidiabetic activities in prevention and treatment modes in multiple low dose (MLD) streptozotocin (STZ) (20 mg/kg i.p injection for 5 days) induced diabetic SD rats. In the prevention mode,150 mg/kg of GRWE was administered intraperitoneally with STG for 3 weeks, and this group is called CO 150. In the treatment mode, we started to administer the same dose of PGWE on day 8 and for 3 weeks, and this group is called POST150. PGWE exerted significant hypoglycemic activities in both prevention (normal control, 97 ${\pm}$ 6 mg/dl; diabetic control, 331${\pm}$23; CO150, 211${\pm}$37) and treatment groups (normal control, 128${\pm}$4 mg/dl; diabetic control, 392${\pm}$33: POST150, 263${\pm}$44). Of great importance is the fact that plasma insulin levels in both groups were markedly increased as compared to the diabetic control (normal control,428.7${\pm}$62.1 pg/dl; diabetic control, 167.0${\pm}$91.7; CO150, 377.6${\pm}$68.7 in prevention mode, and in treatment mode normal control 417.9${\pm}$84.6 pg/dl; diabetic control, 166.1${\pm}$104.7; POST150, 315.2${\pm}$47.4). Blood glucose levels were closely associated with plasma insulin levels, and this result may suggest that PGWE showed the activity to enhance insulin secretion as well as preventing destruction of pancreatic islet cells. Food and water intakes were also determined at the last week of treatment i n both groups. Characteristic symptoms of diabetes were significantly improved in both groups. In the prevention mode, water intake (ml/rat/day) in normal control was increased from 30.6${\pm}$1.5 to 122.2${\pm}$3.4 in diabetic control rats. In the CO150-treated group, water intake was dramatically reduced to 68.3${\pm}$4.4 (p<0.001 vs. diabetic control). In the treatment mode, POST-treated group also reduced the water intake from 128.9${\pm}$2.2 to 113.3${\pm}$1.7. Taken together, our data suggest that PGWE showed comparable antidiabetic activities in prevention and treatment modes. Therefore, PGWE may have a potential as a prophylactic as well as therapeutic agent fur type 2 diabetes mellitus (T2DM).

• Proceedings of the Membrane Society of Korea Conference
• /
• 1999.07a
• /
• pp.39-42
• /
• 1999

Perfluoropolymers represent the ultimate resistance to hostile chemical environments and high service temperature, attributed to the presence of fluorine in the polymer backbone, i.e. to the high bond energy of C-F and C-C bonds of fluorocarbons. Copolymers of Tetrafluoroethylene (TEE) and 2, 2, 4Trifluoro-5Trifluorometoxy- 1, 3Dioxole (TTD), commercially known as HYFLON AD, are amorphous perfluoropolymers with glass transition temperature (Tg)higher than room temperature, showing a thermal decomposition temperature exceeding 40$0^{\circ}C$. These polymer systems are highly soluble in fluorinated solvents, with low solution viscosities. This property allows the preparation of self-supported and composite membranes with desired membrane thickness. Symmetric and asymmetric perfluoropolymer membranes, made with HYFLON AD, have been prepared and evaluated. Porous and not porous symmetric membranes have been obtained by solvent evaporation with various processing conditions. Asymmetric membranes have been prepared by th wet phase inversion method. Measure of contact angle to distilled water have been carried out. Figure 1 compares experimental results with those of other commercial membranes. Contact angles of about 120$^{\circ}$for our amorphous perfluoropolymer membranes demonstrate that they posses a high hydrophobic character. Measure of contact angles to hexandecane have been also carried out to evaluate the organophobic character. Rsults are reported in Figure 2. The observed strong organophobicity leads to excellent fouling resistance and inertness. Porous membranes with pore size between 30 and 80 nanometers have shown no permeation to water at pressures as high as 10 bars. However high permeation to gases, such as O2, N2 and CO2, and no selectivities were observed. Considering the porous structure of the membrane, this behavior was expected. In consideration of the above properties, possible useful uses in th field of gas- liquid separations are envisaged for these membranes. A particularly promising application is in the field of membrane contactors, equipments in which membranes are used to improve mass transfer coefficients in respect to traditional extraction and absorption processes. Gas permeation properties have been evaluated for asymmetric membranes and composite symmetric ones. Experimental permselectivity values, obtained at different pressure differences, to various single gases are reported in Tab. 1, 2 and 3. Experimental data have been compared with literature data obtained with membranes made with different amorphous perfluoropolymer systems, such as copolymers of Perfluoro2, 2dimethyl dioxole (PDD) and Tetrafluorethylene, commercialized by the Du Pont Company with the trade name of Teflon AF. An interesting linear relationship between permeability and the glass transition temperature of the polymer constituting the membrane has been observed. Results are descussed in terms of polymer chain structure, which affects the presence of voids at molecular scale and their size distribution. Molecular Dyanmics studies are in progress in order to support the understanding of these results. A modified Theodoru- Suter method provided by the Amorphous Cell module of InsightII/Discover was used to determine the chain packing. A completely amorphous polymer box of about 3.5 nm was considered. Last but not least the use of amorphous perfluoropolymer membranes appears to be ideal when separation processes have to be performed in hostile environments, i.e. high temperatures and aggressive non-aqueous media, such as chemicals and solvents. In these cases Hyflon AD membranes can exploit the outstanding resistance of perfluoropolymers.

• Journal of Korean Society of Forest Science
• /
• v.101 no.1
• /
• pp.7-19
• /
• 2012

After having announced legislation for threatened or endangered species on the List of Endangered and Threatened Wildlife and Plants in 2005, the Korea Ministry of Environment proposed (in June 2011) amending the list, thereby delisting or reclassifying endangered species using new quantitative criteria for two levels (I and II), as well as status reviews. The new legislation included 40 species remained in their original endangered status, but 19 species were delisted, 5 species were proposed as candidates for delisting, 29 species were given a new endangered listing, and 3 species were proposed for an endangered listing in Korea. We assessed the threatened status of 98 plants using the IUCN Red List Criteria (version 3.1) at the global level, and compared the Ministry's revised criteria with the IUCN Red List Criteria and ESA criteria used in the USA. Most species proposed by the Ministry do not qualify as threatened and one of the major difficulties found in applying IUCN Red List Criteria at the global scale was a lack of knowledge on the status of species at broader geographic scales and the perceived difficulty this causes. Under the current classification process, many endangered species, such as Abeliophyllum distichum, Leontice microrhyncha, Echinosophora koreensis, Leontopodium coreanum, Iris odaesanensis, and Corylopsis coreana at global level were excluded here. Knowledge gaps and uncertainties mean that the number of taxa at high risk of extinction may be substantially greater than is currently understood. Due to a lack of information on its taxonomic status, currently there is controversy over the Red List status of Physocarpus insularis. Also, Caragana koreana, which was an invalidly published name, should be excluded here. Although the Korea Ministry of Environment insisted this procedure was conducted by applying the modified IUCN threat categories and definitions, this evaluation has been carried out based only on subjective views and misapplication of the IUCN Red List Criteria. The current listings by the Korea Ministry of Environment should be challenged. We suggest that broad species concepts on endemic species are applied and also criteria that adequately address the proper quantitative knowledge should be used. It is suggested that the highest priorities for the Red List should be given to endemic species at least in the Korean peninsula first at global scale.

• Economic and Environmental Geology
• /
• v.40 no.4
• /
• pp.347-360
• /
• 2007

In order to evaluate the degree and extent of heavy metal pollution and the environmental impacts of abandoned Cu mines in Goseong-gun, soils and paddies were collected from the mine area and have been analysed for heavy metal contents. The heavy metal contents were much higher in mountain soils than in paddy soils. Total content of heavy metals decreased in order of Cu>Zn>Pb>As>Cr>Cd in mountain soils whereas Zn>Pb>Cu>Cr>As>Cd in paddy soils. The extractable amount of heavy metals by 0.1/1N HCl decreased in order of Cu>Pb>Zn>As>Cd>Cr in mountain soils whereas Pb>Cu>Zn>As>Cd>Cr in paddy soils. Although the extraction ratios were highly various depending on the sampling site, their average values were in order of Cd(16%)>Pb(10%)>Cu(9%)>As(4.5%)>Zn-Cr(${\le}2.5%$). The soils investigated were enriched in heavy metals relative to the averages of earth crust as In order of $As{\ge}Cd$>Pb>Zn>Cu>Cr. Pollution index calculated from total or extractable heavy metals of soils indicated that the heavy metal pollution was restricted to mountain soils around abandoned Cu mines, especially the Samsan I mine. The metal contents of brown rice showed no significantly contaminated level as follows; As $nd{\sim}0.87mg/kg,\;Cd\;0.02{\sim}0.34mg/kg,\;Cu\;1.01{\sim}6.25mg/kg,\;Mn\;13.4{\sim}43.2mg/kg,\;Pb\;0.09{\sim}2.83mg/kg,\;and\;Zn\;16.5{\sim}79.1mg/kg$. From the extraction and dispersion properties of heavy metal with the soil pH ($4.5{\sim}7.8$), it can be deduced the conclusion that the heavy metal pollution is spreading in the study area mainly by the detrital migration of waste ore and gangue minerals rather than the dissolution and circulation of heavy metal.

• Korean Journal of Weed Science
• /
• v.8 no.2
• /
• pp.199-207
• /
• 1988

The study was intended to know any relations between the rice tolerance to oxyfluorfen and varietal speciation in seed protein composition or any enzymatical allelies with or without chemical treatment. Rice varieties used were Chokoto, Aichiasahi, Agabyeo, IR 3941 and Tablei as the tolerant group, and Mushakdanti, Weld Pally, HP 1033, HP 857, and HP 907 as the susceptible, respectively. Electrophoretic methods used were SDS-PAGE for seed protein, 7% PAGE for isozymes (acid phosphatase and peroxidase from rice seedling) and changes in isoenzyme activity (malate dehydrogenase, peroxidase and esterase) as affected by oxyfluorfen treatment ($10^{-4}M$) was also studied. The results are summarized as follows. -Among 19 bands separated in seed proteins, two different rice groups selected in terms of tolerance were clustered in dissimilarity. This was based on 2 facts in that G band was not present in susceptible varieties and that less activity of H, N, O, P, Q, Rand S band was shown. -Among 4 bands separated in acid phosphatase, the presence of (band and lower activity of B band was specific for tolerant varieties. For 4 minor bands separated in peroxidase, the tolerant varieties had no activity in B band and higher activity in A, C, D bands. -Time-course study of isozymes as affected by $10^{-4}M$ oxyfluorfen showed that Chokoto, the tolerant varieties, had little activity in A band and consistently higher activities in Band C bands for malate dehydrogenase. For 5 bands separated in peroxidase, B band was not found in Chokoto while A, C, D, and E bands were consistently present. Esterase was separated into about 4 bands in which Chokoto had maintained higher activities in A, C and D bands.