• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.207-213
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• 1976

In order to obtain the prediction of the maximum dry density and the optimum moisture content of soil without soil moisture test, compaction test results from 157 different places either under construction or already completed were analyzed. The analyzed results were as follow The relationship between the maximum dry density and the optimum moisture content of the soil showing a correlation coefficient of 0.96 indicated that there was a high correlation between them. From the above relationship we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.4193+0.00937W_{opt.}}$ Equation between the optimum moisture content and the maximum wet density of the soil was $W_{opt.}={\frac{0.4193{\gamma}_{tmax.}}{0.937_{\gamma}_{tmax.}-0.01}$, and the values of the optimum moisture content being predicted with the maximum wet density of the soil showed a little difference between those and tested values. The values of the maximum dry density being predicted with the moisture content estimated by the maximum wet density of the soil were within the range of ${\pm}5%$ of its tested values. The relationship between the dry density and the void ratio showed a high correlation between them (${\gamma}=0.9706$). From the above relationship, we obtained the equation, ${\gamma}_{dmax.}={\frac{1}{0.3938+0.3426e}}$.

• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.5-9
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• 1977

1. Chemical properties of soils and inorganic compositions of rice plants were analysed to explain the acute wilting occurred in the late stage of rice variety, Yusin. The results obtained were summarized as follows. 1) The amount of K and $SiO_2$ of soils where severe rice wilting occurred was lower than that of soils where rice wilting didn't occurred. 2) The amount of N and FeO of wilted rice plants was higher than that of normal rice plants while the amount of $K_2O$ and $SiO_2$ and the ratio of $K_2O/N$ of former were lower than that of letter. 2. Severe wilting was occurred only in the rice variety, Yusin, when three varieties${\cdots}$ Yusin, Milyang #15, Milyang #23${\cdots}$were interplanted. The amount of organic and inorganic compositions of three varieties and chemical properties of rhizosphere soils were analysed. 1) The rice variety, Yusin, was the lowest and that of the rice variety, Milyang #15, was the highest in the level of total carbohydrate and hemicellulose. 2) Comparatively higher levels of K were observed in rhizosphere soil where Yusin was planted, while the level of the K in the plant of Yusin was the lowest.

• Applied Biological Chemistry
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• v.11
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• pp.49-53
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• 1969

Some properties of glucose isomerizing enzyme which produced by the strain K-17 in xylose containing nutrient broth medium were investigated. The optimal pH for enzyme reaction was indicated about 7.2 and optimal temperature was about $75^{\circ}C$. The same optimal temprature was indicated by both cell free extract and acetone dried cells using as enzyme. The glucose isomerizing enzyme from strain K-17 was not inhibited by the high concentration of substrate even in a suturated glucose solution, but most enzyme was inactivated by the heat treatment at $80^{\circ}C$. The maximum fructose forming ratio from glucose was about 50 percents.

• Applied Biological Chemistry
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• v.11
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• pp.55-61
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• 1969

This K-17 strain was not absolutely requiring xylose as an inducer for enzyme formations. The most activity of this enzyme was lost when treated at $75^{\circ}C$. for 30 hours but was not influenced at $70^{\circ}C$. for 70 hours of treatment. The activity of this enzyme was increased by the addition of magnesium ions or cobalt ions in the reaction system. In the studies, we found that the magnesium ions simply activate the enzyme reaction and the cobalt ions do not but protect the enzyme from heat inactvation. And it was also found the phosphate buffer solution was very suitable as glucose dissolving solvent on the enzyme reaction. The mixed carbon source medium containing glucose, fructose, sorbitol, xylose and sucrose was more favorable for enzyme production then a sole carbon source containing medium on the shaking culture method.

• Journal of the Korean Mathematical Society
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• v.42 no.6
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• pp.1153-1167
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• 2005

In this paper, all rings and all near-rings R are associative, all modules are right R-modules. For a near-ring R, we consider representations of R as R-groups. We start with a study of AGR rings and their properties. Next, for any right R-module M, we define a new concept GM module and investigate the commutative property of faithful GM modules and some characterizations of GM modules. Similarly, for any near-ring R, we introduce an R-group with MR-property and some properties of MR groups.

• Korean journal of applied entomology
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• v.21 no.1 s.50
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• pp.1-7
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• 1982

This study was conducted to describe unrecorded five species of thrips from leaf litter and dead wood in Korea. Described three species of Elaphrothrips 1,2,3, Podothrips sasacola and Pentagonothrips antennalis are for the first time in Korea. Specimens of thrips were collected in the area of Suweon, Jeju-Do., Mt. Seolag and Mt. Jiri in Korea, during the period from 1980 to 1981.

• Korean journal of applied entomology
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• v.10 no.2
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• pp.69-73
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• 1971

The study was conducted to describe unrecorded six species of thrips; Thrips hawaiiensis f. imitator (Priesner),? Helionothrips antennatus Kurosawa, Franklimiella intonsa (Trybom), Microcephalothrips abdominalis (Crowford), Megalurothrips distalis (Karny) and Haplothrips chinensis Priesener. Specimens of thrips were collected in the area of Suwon, Kwang-Neung and Seoul, Korea, during the period of August to December in 1970.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2002.11a
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• pp.70.1-70
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• 2002

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.573-583
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• 2005

In this paper, all near-rings R are left near-rings and all representations of R are (right) R-groups. We start with a study of AR, almost AR and AGR rings which are motivated by the works on the Sullivan's Problem [10] and its properties. Next, for any R-group G, we introduce a notion of R-groups with M R-property and investigate their properties and some characterizations of these R-groups. Finally, for the faithful M R-property, we get a commutativity of near-rings and rings.

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.81.2-81.2
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• 2006