• The Korean Journal of Mycology
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• v.6 no.2
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• pp.19-24
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• 1978

Four species of Pythium and two species of Sclerotium previously not recorded in Korea during 1976 and Leptosphaeria salvinii which previosly reported but reidentified. Pythium aristosporm Vantery, Pythium sp. and Pythium myriotylum Drechsler were isolated from diseased rice seedlings and from green withered rice plants and Pythium irreglare Buisman was isolated from paddy soil. Three species of Pythium except P. irregulare grew well at $40^{\circ}C$ on Potato dextrose agar and were confirmed as highly pathogenic but P. irregulare showed low pathogenicity on Yushin variety of rice. Sclerotium hydrophilum and Sclerotium oryzae-sativae appeared to be weakly pathogenic, but Leptosphaeria salvinii was confirmed as a highly pathogenic. Ordinally the two species of Sclerotium grew and produced many sclerotia on dead sheath and stems of rice. There are still some problems to clarify and reconsider in regard to the pathogenicity of the sclerotial fungi because their populations were so very high in paddy fields, but their role might be wound parasite.

• Journal of Nutrition and Health
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• v.2 no.4
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• pp.113-125
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• 1969

These experiments were designed to study the influence of early protein undernutrition on growth, behaviors toward food, general attitude toward a new environment, brain size and body composition of the experimental rats. The following experimental groups were studied. Lactation period (3 weeks) (Diets of mother rats) 25% Casein diet 12% Casein diet 25% Casein diet 25% Casein diet 12% Casein diet 12% Casein diet After-weaning protein deprivation period None deprivation (25% Casein diet) None deprivation (25% Casein diet) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) 5% Casein diet (4 weeks) 5% Casein diet (8 weeks) After a long period of rehabilitation with 25% casein diet the following results were obtained. 1. Growth rate during lactation period is closely related with the protein levels of the diet for mother rats. The average body weight of offsprings of the mother rat fed 25% casein diet is 46.0 grams at 21 days old. However, that of the mother rat fed 12% casein diet is only 25.0 grams. 2. The group of protein undernutrition during lactation (S weeks) (offsprings of mother rat fed low protein diet, 12% casein diet) could never catch up with the normal group in its growth even after twenty-four (24) weeks of rehabilitation. 3. However, the groups of protein undernutrition during either four (4) or even eight (8) weeks after weaning could catch up with the normal group in their growth after long period of rehabilitation. 4. The absolute amounts of carcass protein and fat of the normal group are larger than those of the protein deficient groups. In terms of percent carcass, however, the normal group showed higher body fat and lower body protein than the early deficient groups. However, there is no difference between preweaning (3 weeks) and postweaning (8 weeks) deficient groups. It is assumed, from these differences in body composition, that there might be any differences in physiological and metabolic functions among these various groups, and also that the basic formation of various metabolic regulators (protein-nature) might be fixed mostly during lactation and postweaning period. 5. The groups of protein undernutrition during either three (3) weeks lactation or four (4) weeks after weaning are not so remarkably different from the normal group in their amounts of food intake and spillage. However, the groups of undernutrition during either eight (8) weeks postweaning or eleven (11) weeks (3 weeks lactation period plus 8 weeks postweaning period) showed higher amounts of food intake and spillage. In these respects, it seems that desire for food is closely related with the degree of early hunger in protein and also seems that the longer be deficient in early life the more food spillage is found. 6. Both preweaning and postweaning deficient groups showed generally nervous and restless. The normal group is staid and showed less mobilities. 7. The average size of the brains of the group subjected to protein deficiency during three (3) weeks lactation period is smaller than that of the group of the eight (8) weeks postweaning deficiency. This means that the development of the brain is made mostly during lactation period. The group of the eleven (11) weeks postnatal deficiency is significantly different from the normal group in its brain development. It is assumed, in connection with the results of various maze tests reported, that the brain size is closely related with the intellectual ability.

• Journal of Preventive Medicine and Public Health
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• v.31 no.4 s.63
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• pp.666-679
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• 1998

This study aims at providing the fundamental data on the field of cosmetics by comparing heavy metal concentration in terms of domestic/foreign products, items, companies and colors. This study has determined the concentration of chromium, lead, mangagnese, nickel, copper and vanadium in cosmetics such as moisturizer, concealer, foundation (Ivory-yellow), compact powder (Ivory-yellow), lip colo. (Red, brown), eye shadow (Red, brwon and dark green) and eye liner (Black) manufactured by five domestic cosmetic companies and five foreign cosmetic companies on the market. The samples have been collected in cosmetic stores in Pusan from Dec. lst 1996 to Jan. 3lst 1997. The results are as follows : 1. The heavy metal concentration in cosmetics was $2.420{\mu}g/g$ for chromium, $0.82{\mu}g/g$ for lead, $4.49{\mu}g/g$ for manganese, $1.69{\mu}g/g$for nickel, $0.53{\mu}g/g$ for copper, and $51{\mu}g/g$ for vanadium, respectively. 2. Lead and vanadium concentration were significantly higher in domestic cosmetics than foreign cosmetics(p<0.05). 3. The mean(GM) concentrations of heavy metal were different significantly (p<0.01) when classified with cosmetic items. The highest means shown at eye shadow in $Cr(14.96{\mu}g/g),\;Cu(1.32{\mu}g/g),\;V(1.28{\mu}g/g),\;and\;Ni(8.30{\mu}g/g)$, compact powder in $Pb(2.50{\mu}g/g)$, eye liner in $Mn(90.62{\mu}g/g)$. 4. The mean(GM) concentrations of heavy metal were different significantly (p<0.01) among colored cosmetics. The highest mean concentration of Cr, Ni, Cu and V were dark green-colored cosmetics, that of Mn was black-colored cosmetics, and that of Pb was ivory yellow- colored cosmetics.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.15-26
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• 2014

This study focus on a economic value of the Big Data technologies by real options model using big data technology company's stock price to determine the price of the economic value of incremental assessed value. For estimating stochastic process of company's stock price by big data technology to extract the incremental shares, Generalized Moments Method (GMM) are used. Option value for Black-Scholes partial differential equation was derived, in which finite difference numerical methods to obtain the Big Data technology was introduced to estimate the economic value. As a result, a option value of big data technology investment is 38.5 billion under assumption which investment cost is 50 million won and time value is a about 1 million, respectively. Thus, introduction of big data technology to create a substantial effect on corporate profits, is valuable and there are an effects on the additional time value. Sensitivity analysis of lower underlying asset value appear decreased options value and the lower investment cost showed increased options value. A volatility are not sensitive on the option value due to the big data technological characteristics which are low stock volatility and introduction periods.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1448-1455
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• 1998

Fermented milk was prepared from milk or mixture of milk and apple juice/grape juice, and it was freeze dried. pH change and growth of Lactobacillus acidophilus (KCTC 2182) during freeze drying were studied. The effects of freeze drying on sensory evaluation and volatile aroma compounds in freeze dried sample or reconstituted sample were also studied. Freezing and freeze drying did not affect pH of fermented milk. Number of viable cells of L. acidophilus was markedly reduced during freezing or freeze drying. When number of viable cells in original fermented milk was considered as 100%, survival ratio of viable cells after freezing was $64.5{\sim}85.2%$ and that after freeze drying was $10.0{\sim}21.1%$. When sensory properties of original fermented milk prepared from juice-milk (ratio 15:35) were compared with those of freeze dried/reconstituted sample, sensory properties of original sample were better than those of freeze dried/reconstituted sample. Ethanol, diacetyl, butanol and acetoin were detected in all of original samples and freeze dried/reconstituted samples while acetone was detected in samples containing high amount of grape juice. Volatile aroma compounds in original fermented milk were reduced during freeze drying. L. acidophilus produced ethanol, diacetyl and acetoin during fermentation.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.45-56
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• 2009

Current status on the occurrence and the management of the major disease, insect and mite pests were investigated in the organic or non-chemical pest control orchards from 2005 to 2009. Numbers of certified organic or non-chemical apple orchards were increased from 14 in 2005 to 78 in 2008. Severe damages on leaves and fruits occurred by the several diseases such as marssonina blotch, bitter rot, white rot, sooty blotch and flyspeck, and the several insect pests such as apple leaf-curling aphid, woolly apple aphid, oriental fruit moth and peach fruit moth on the almost certified organic or non-chemical pest control orchards. About 10 and 18 environmental-friendly materials were used to control diseases and insect or mite pests respectively. But, lime sulfur and bordeaux mixture to diseases and machine oil, plant oil mixed with egg yolk, and pheromone mating disruptions to insect pests were effective to control under the adequate conditions. At present, it is extremely difficult to produce organic apples in Korea. Growers must consider about and solve so many conditions on the cultivar, weather, local site, marketing and so on, before when they decide to change from conventional or IPM(Integrated Pest Management) to organic or non-chemical pest control orchards.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.228-233
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• 2007

Pear psylla, Caccopsylla pyricola (Homoptera: Psyllidae), is a serious insect pest in pear orchards. C. pyricola overwinters as adults under rough bark scales of pear trees. When the weather warms up in the spring, the overwintered adults become active, climb up to the tree branches, and inhabit on fruit twigs to lay eggs. This study was conducted to develop a forecasting model for the onset of upward-movement of overwintered C. pyricola adults to control them by timely spraying of petroleum oil. The adult population densities were observed under rough barks (B) and on fruit twigs (T) of pear trees. Relative upward-movement rates (R) were calculated as T/(B+T). Low threshold temperatures for the activation of overwintered C. pyricola adults were selected arbitrarily from 5 to $9^{\circ}C$ at a $1^{\circ}C$ interval. Then, the days (D) when daily maximum air temperatures were above each low threshold temperature were counted from 1 February until to the dates with R $\geq$ 0.8. The same methods were applied for the prediction of the first observation of eggs. The variation of coefficients (CV) for the mean Des were lowest with the low threshold temperature of $6^{\circ}C$. At this selected threshold temperature, the upward movement of C. pyricola adults occurred with 12 D and they started laying eggs with 25 D. In the field validation, the model outputs with the $6^{\circ}C$ threshold temperature reasonably well explained the observed data in Suwon and Cheonan in 2002. Practical usages of the model were also discussed.

• Korean Journal of Agricultural Science
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• v.14 no.1
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• pp.38-50
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• 1987

The purpose of this comparative study is to investigate the differences of growth behaviors (height, weight, yield capacities etc.) and germination characters (induced photo-dormancy) among the three different species of Arnaranthus sp. The results obtained are summarized as follows. The growth of the cultivar of A.hypochondriacus was more vigor than that of the wild plant of A.retroflexus during the whole life cycle. The fresh weight, dry weight, yield capacity of A.hypochondriacus were much more higher than those of the others two species (A.retroflexus and A.Cruenthus). There are very different germinability formation and induced dormancy patterns between the cultivar and wild plant during seed formation periods. The cultivar of A.hypochondriacus was not induced primary dormancy in the any seed formation stages but wild plant of A.retroflexus was induced deep true dormancy. We suggested that these differences occured by the sum of different absorption of solar energy spectrum by the different seed colors between the cultivar (white color seed) and wild (black seed). And we confirmed the different absorption spectrum of the three different Arnaranthus sp. seeds.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.221-232
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• 2010

During 2005~2009, current status on the occurrence and the management of the major disease, insect and mite pests were investigated in the non-chemical or organic cultured apple orchards in Korea. Numbers of certified organic or non-chemical apple orchards increased from 14 in 2005 to 78 in 2008. Severe damages on leaves and fruits were caused by the several diseases such as marssonina blotch, bitter rot, white rot, sooty blotch and flyspeck, and the several insect pests such as apple leaf-curling aphid, woolly apple aphid, oriental fruit moth and peach fruit moth on the almost certified organic or non-chemical pest control orchards. About 10 and 18 environmental-friendly materials were used to control diseases and insect or mite pests, respectively. But, lime sulfur and bordeaux mixture to diseases and machine oil, plant oil mixed with egg yolk, and pheromone mating disruptions to insect pests were effective under the adequate conditions.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.445-455
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• 2014

The pear sucker (Cacopsylla pyricola) is the most important insect pest in Korea. The hatching rates of overwintered adults laid eggs were observed at 10, 13, 18, and $22^{\circ}C$. The liner model was draw as Y=0.00277X+0.00146(Y=developmental rate, X=temperature) about temperature and developmental rate to eggs. The developmental threshold temperature to eggs was assumed about $-0.83^{\circ}C$. The egg hatching timing over 50% as the accumulated temperature by day maximum temperature $6^{\circ}C$ over from 1st February in 2008, 2009 and 2011 was 429.7, 417.6, and 424.3 degree $^{\circ}C$, respectively, was 3 to 7days before full blooming in pear orchard. On the other hand, the abamectin 1.8EC, lime sulfer, machine oil and 13 kinds of eco-friendly materials were not shown the control effect to the eggs. To mixed stage of pear sucker, the eco-friendly materials over 90% control value were 4 kinds such as a mixture of Azadiractin A+B, Nimbin, Salanin, Meliantriol and Vepol after twice application as 21st May and 5th June in pear growing season, in 2012.