• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.3
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• pp.253-260
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• 1992

In this study, the dielectric, structural and electrical properties of Pb(ZnS11/3TNbS12/3T)OS13T-BaTiOS13T-PbTiOS13T system ceramics were investigated with respect to the variation of YS12TOS13T addition amount. As the YS12TOS13T addition amount is increased, the resistivity at 100$^{\circ}C$ and the resonant/antiresonant frequencies and the frequency constant are slowly increased, and the grain growth is restrained until 0.4 wt% YS12TOS13T addition amount but continuously increased with the addition amount more than 0.4 wt% YS12TOS13T. As the YS12TOS13T addition amount is increased, the density, the diffuseness of dielectric constant and the induced polarization are increased until 0.4 wt% YS12TOS13T addition.

• Journal of the Korean Ceramic Society
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• v.28 no.10
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• pp.767-776
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• 1991

Effects of the additions of SiB4 as burnable poison to UO2 on the green density, densification, interdependence between density-grain growth and microstructure of sintered UO2 were studied. UO2 pellets were sintered in flowing hydrogen, at temperature 1200, 1350, 1500, and 168$0^{\circ}C$ for 3 hours and at 168$0^{\circ}C$ for 0, 1, 3, and 10 hours, respectively. Green densities were in the range of about 4.5~5.4 g/㎤, and decreased as the amount of SiB4 increased when green pellets were made by with use of a double action press at 1000 kg/$\textrm{cm}^2$. The density of sintered UO2 pellets was around 92~94% of the theoretical density and did not change significantly as the amount of SiB2 addition increased. However, the density of sintered pellets decreased with the increase in SiB4. The grain growth could be characterized in terms of two stages: Grain growth occurred with the increasing density in the first stage, whereas the second stage was characterized by the grain growth without increasing of density. A liquid phase was observed at grain boundaries and grain edges in the microstructure of sintered UO2 pellets with 5000 ppm and 10,000 ppm SiB4. This liquid, possible formed at about 168$0^{\circ}C$, did not enhance the shrinkage, but appeared to accelarate the grain growth. It seems that the second stage grain growth was due to the presence of pressurized insoluble trapped gas in isolated pores.

• Journal of Powder Materials
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• v.27 no.2
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• pp.126-131
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• 2020

The grain growth behavior of M-type Sr hexaferrite (SrM) grains is investigated with the addition of MnCO₃. First, the SrM powder is synthesized by a conventional solid-state reaction. The powder compacts of SrM are sintered at 1250℃ for 2 h with various amounts of MnCO₃ (0, 0.5, 1.0, and 4.0 mol%). There is no secondary solid phase in any of the sintered samples. Relative density increases when MnCO₃ is added to the SrM. Obvious abnormal grain growth does not appear in any of the SrM samples with MnCO₃. The average grain size increases when 0.5 mol% MnCO₃ is added to the SrM. However, as the amount of MnCO₃ increase to over 0.5 mol%, the average grain size decreases. These observations allow us to conclude that the growth of SrM grains is governed by the two-dimensional nucleation grain growth mechanism, and the critical driving force for the growth of a grain decreases as the amount of MnCO₃ increases.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.338-345
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• 2023

Bacillus spp. and Saccharomyces spp. are effective microorganisms that are applied as microbial fertilizers for crops in Korea. Mixed organic fertilizer (MOF) has been used in the Korean organic agriculture to supply nutrients to crops. This study was conducted to investigate the effects of MOF containing Bacillus amyloliquefaciens HSOB-7 and Saccharomyces cerevisiae HSOB-8 (MOFBS) on the soil chemical properties and growth of lettuce (Lactuca sativa). Growth factors of lettuce were higher after applying different formulation types of MOFBS, such as powder and pellet, than those of NF, and not significantly different than those of control (microbe-free MOF). Compared with the control, application of recommended amount of MOFBS (MOFBS 250 kg/10a, MOFBS treatment) and double the recommended amount (MOFBS 500 kg/10a, 2MOFBS treatment) did not significantly change the growth factors of lettuce. After the application of two formulation types or two different amounts of MOFBS, soil chemical properties such as electrical conductivity, organic matter (OM), exchangeable Ca, and cation exchangeable cation (CEC) increased. These results indicated that although the application of MOFBS improved soil fertility including OM and CEC, it did not significantly affect lettuce growth.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.462-471
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• 1996

This study was conducted to investigate the effects of meteorological changes on tree growth due to the reservoir construction. First, climatic normals were estimated before and after the reservoir construction at the area of Imha, through the topoclimatological relationships. Secondly, the amount of meteorological changes was quantified based on the difference analysis of the climatic normals. Thirdly, the diameter increments of Pinus densiflora around Imha area were measured with increment borer. Sample trees were taken on the 6 points of 30m, 100m, 500m, 1km, 3km, and 5km from the reservoir, respectively. Finally, effects of meteorological changes on tree growth were investigated based on the analysis of tree ring increment patterns. Results showed that the growth of trees within the range of 1km from the reservoir had been increased, but the growth of ones out of 1km range had no relationship with meteorological changes after the reservoir construction. It seems that the diameter increment of trees grown near reservoir has been increased mainly due to the increased solar radiation in spring and the increased total amount of precipitation during growing season, compared with those before the reservoir construction. It is supposed, however, that the changes of monthly mean temperature has little effect on the tree growth because of its small amount of changes.

• Journal of the Korean Society of Tobacco Science
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• v.2 no.2
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• pp.44-50
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• 1980

The growth of flue-cured tobacco was analyzed with the mathematical treatment. The results are summarized as followings: 1. The growth curve was fitted to the quadratic polynomial equation in improved-mulching cultivation, blot to the Gompertz equation in the other cultivations. 2. The initial point of the maximum growth phase for dry weight was about 50 days after transplanting in improved-mulching cultivation, but about 40 days in the other cultivations, and the maximum growth period was for 25 days in all cultivations. 3. The growth rate of the maximum growth period in dry weight decreased in the order of improved-mulching cultivation, mulching cultivation, and non-mulching cultivation. 4. A relative growth amount in the maximum growth period was higher in later sowing. 5. The length of maximum growth was 5 days shorter in leaf area than in dry weight. The maximum growth phase was 7 days earlier in leaf area than in dry weight.

• Microbiology and Biotechnology Letters
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• v.24 no.3
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• pp.336-343
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• 1996

Maximum amount of the aminopeptidase M inhibitors produced by Streptomyces griseoplanus SL20209 in 500 ml-Erlenmeyer flask was accumulated after cultivation for 3 days at 28$\circ$C, thereafter the amount of inhibitors decreased slowly with a pH change to alkaline. Arabinose, xylose, mannose and soluble starch were good carbon sources for the production of the inhibitors. On the other hand, glucose was only good for the cell growth but potently inhibited the production of inhibitors. Natural organic nitrogen sources such as soybean meal, fish meal, gluten meal and peanut powder were good for the production of inhibitors, however, soytone, peptone and inorganic nitrogens such as NH$_{4}$C1 and NH$_{4}$NO$_{3}$ were poor. Inclusion of yeast extract (0.5%, w/v) or K$_{2}$HPO$_{4}$ (0.05%) into the production medium increased the production of inhibitors by accelerating cell growth. The production of inhibitors was slightly increased on the medium containing CaCO$_{3}$ (0.3%) and zeolite (0.5%), respectively. Optimal temperature and initial pH range for the production ot inhibitors were determined to be 28$\circ$C and 6.0-7.0, respectively. Employing two improved production media consisting of 3% arabinose or soluble starch, 2.5% soybean meal, 0.5% yeast extract, 0.05% K$_{2}$HP0$_{4}$, 0.1% CaCO$_{3}$ and 0.3% zeolite (pH 6.8), 1.8-fold increase in the amount of inhibitors was achieved, comparing with the basal medium used.

• Journal of the Korean Ceramic Society
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• v.42 no.5 s.276
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• pp.338-345
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• 2005

To prepare the complex gel of flux and pseudo-boehmite used in precursor of the flaky ${\alpha}-A1_2O_3$ crystal, aqueous solution of the mixture of sodium carbonate and sodium phosphate was added with stirring in aqueous solution of the mixture of sodium sulfate, potassium sulfate and titanium sulfate. The complex gel was dried at $110^{\circ}C$ and was crystallized above $1,050^{\circ}C$, and then the effect of the amount of titanium sulfate on size, morphology, thickness and crystal size distribution of the flaky ${\alpha}-A1_2O_3$ crystal was investigated. Addition of titanium sulfate was prevented the aggregation and generation of twin crystal, and had an effect on the crystal size and the thickness during crystal growth. When the amount of titanium sulfate was more than 6 g, particle size was decreased but was free from crystal twining and aggregation. On the other hand, when the amount of titanium sulfate was lower than 6 g, crystal size was increased but crystal twinning and aggregation were noticed.

• Journal of Information Technology Applications and Management
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• v.12 no.2
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• pp.1-13
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• 2005

This paper proposes a software-reliability growth model incoporating the amount of testing effort expended during the software testing phase after developing it. The time-dependent behavior of testing effort expenditures is described by a Logistic curve. Assuming that the error detection rate to the amount of testing effort spent during the testing phase is proportional to the current error content, a software-reliability growth model is formulated by a nonhomogeneous Poisson process. Using this model the method of data analysis for software reliability measurement is developed. After defining a software reliability, This paper discusses the relations between testing time and reliability and between duration following failure fixing and reliability are studied. SRGM in several literatures has used the exponential curve, Railleigh curve or Weibull curve as an amount of testing effort during software testing phase. However, it might not be appropriate to represent the consumption curve for testing effort by one of already proposed curves in some software development environments. Therefore, this paper shows that a logistic testing-effort function can be adequately expressed as a software development/testing effort curve and that it gives a good predictive capability based on real failure data.

• Magazine of the Korean Society of Agricultural Engineers
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• v.16 no.2
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• pp.3430-3437
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• 1974

.It is very importaut to know the water consumption of crops in planning irrigation works and practicing suitable soil moisture management. For the purpose of making it clear that how much water be consumed to cultivate the Chinese cabbage, Chamber method has been applied. Main equipments in the transpiration chamber are flowers, manometer and electric thermograph. The chamber made of vynyl plate has a small entrance at the base and an exit at the top, and the ventilation in the chamber was carried out by a flower through the entrance and exit. Air-flow adjusted by an orifice manometer enters the chamber from the outside over the crop canopy through the pipe like a chimney and finally goes out to the outside. Two sets which consist of a pair of dry and wet bulb made by thermistor are installed in the entrance and exit tube, and record air temperature automatically. Evapotranspiration amount is computed from the air-flow quantity and difference in absolute humidity between at the entrance and exit of the chamber by the following equation: ET=(X2-X1)${\times}$Q where ET=evapotranspiration amount X1=absolute humidity at the entrance(g/㎥) X2=absolute humidity at the exit(g/㎥) Q=air-flow quantity(㎥) This study was carried out at the upland farm of the Institute of Agriculture Engimeering and Utilization, Suwon, Korea. from 1971 to 1973. The results obtained in this experiment are as follows: 1. The total amount of evapotranspiration of Chinese Cabbage that is cultivated in autumn is 408.1mm during growth period. 2. Chinese cabbage rapidly grows up in the second ten days of September, 40th to 50th days after seeding. At the same time, the maximum amount of evaportranspiration of Chinese cabbage is 61.6mm/10 days 3. The correlation between Pan-evaporation and evapotranspiration is high, coefficient of correlation r=0.88**, and can be shown as The following regression equation: ET=0.913E+20.273 4. Evapotranspiration is closely related with meteorological factors: r=0.85**, for insolation, r=0.76** for air temperature, respectively. 5. The percentage of evapotranspiration amount, at the beginning of growth stage, gradually increases in proportion as the Chinese Cabbage grows but is largely affected by meteorological factors after the green cover formation. 6. By Blaney and Griddle formula, evaportranspiration coefficient "K" are within from 0,85 to 1.27.