• Korean Journal of Construction Engineering and Management
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• v.12 no.2
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• pp.89-100
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• 2011

As an impactive factor on industries and national economy, The Social Overhead Capital(SOC) is major factor to determine the national competitiveness and the investment of SOC is essential for its economic growth. Accordingly, introduction of the preliminary feasibility study and establishment of legal institutionalization and evaluation system has been carried out and reviewed since 1999. Nevertheless of these efforts, basic problems such as lack of scientific method for investment evaluation and loss of effectiveness on feasibility studies are continuously being brought up. Moreover, as the preliminary study to improve the mentioned problems is mainly focused on the economic and estimated demand analysis, the study of policy analysis, the most important phase during a feasibility study, is still insufficient. Therefore, in this paper, a quantitative decision-making model, to which the performance assessment method of Value Engineering(VE) is applied, is developed and proposed to improve the policy analysis of (preliminary) feasibility study that requires combining with relative studies, to induce quantitative analysis method, and to contribute the improvement of value on the political aspect for SOC investment goals and use as a strategic decision-making method by systematic analysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.212-217
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• 1981

The evaluate the effect of plant spacing on cured leaf of burley tobacco, the row spacings divided to 90, 105, 120cm and hill spacings to 30, 35, 40cm within each row. Growth amount per plant increased with thinner row and wider hill spacing in the same planting density. Relative light intensity increased with thinner row spacing in cutters and leaf and showed the positive correlation with quality. When the planting density was equal, the wider hill spacings, the more effective in utillization of solar radiation. The more plants per l0a were, the greater yield was obtained, and in the case of 3,200 plants per 10a (the most dense planting plot) was 267kg. But, quality, total-alkaloid and total-nitrogen content decreased with dense planting. Value per 10a was highest in the plots of 90 $\times$ 40cm and $105{\times}40cm$. In conclusion the optimum density level was 2,400 to 2,700 plants per 10a and spacing of tobacco either in 105 $\times$ 35 cm or 105 $\times$ 40cm seems to be most appropriate.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.2
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• pp.38-48
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• 1980

To evaluate Rhizobium meliloti BALSAC, a strain selected from Canada as an acid tolerant one, and ordinary lucerne inoculant in acid condition, lucerne (Medicago sativa L. cv. Wairau) was inoculated and/or pelleted in the laboratory, and grown for two months in an acid soil (Lismore silt loam, pH 5.4) with three levels of lime in the, glasshouse. The results of controlled (noninoculated), nitrogen fertilized, laboratorial and commercial inoculated seeds were compared to give the following conclusions: 1. There was no significant difference in the top and root dry matter yields between two Rhizobium strains. However, Balsac inoculant showed higher single nodule dry matter weight and relatively higher number of larger nodules than the ordinary inoculant. 2. Lime application increased dry matter yields of plants and nodules, and the number of nodules per pot and the increase of nodules on the lateral roots in both inoculants. Lime application also caused an evenly distribution of nodules on the root by showing an increase of nodules mainly on the lateral roots. 3. Fertilizer nitrogen without inoculant slightly increased the nodulation percentage, the nodule dry matter weight per nodule and the relative proportion of larger nodules. 4. Commercially inoculated and pelleted seed showed less consistent results. 5. Relatively larger variations in measuring nodule characteristics was discussed and concluded that extreme cares should be given to reduce the variation.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.48-54
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• 1997

Among the various vegetables eggplant and gourd family can stand against high temperature environmental condition, about 35$^{\circ}C$. However, most of greenhouse farmers are giving up crop cultivation during hot summer season due to extreme temperature, 4$0^{\circ}C$ or above, condition of greenhouse interior. To improve this inferior crop growth condition, for nozzle system was installed in the pet greenhouse and the effect of fog system was investigated in order to determine fog water amount and the required fog nozzle numbers according to house volumes. MEE fog nozzle was selected for this Investigation which can produce water particle size of 27${\mu}{\textrm}{m}$ with water amount of 100$m\ell$ at pumping pressure of 70kg/$\textrm{cm}^2$. House cooling test was conducted in the pet greenhouse with one minute fogging and one minute air ventilation without stopping. It maintained 32$^{\circ}C$ at the house interior when the atmosphere and the house temperature were 35 and 4$0^{\circ}C$, respectively. And, an experimental equation was developed through calculating the changes of relative humidity and temperature with psychrometric equation which revealed the moisture transfer pattern between the house air and fog system. It showed that the required water fogging amounts to reduce 1$0^{\circ}C$, 40 to 3$0^{\circ}C$, needs 80.7$\ell$ for 1-2W(8,350㎥) and 99.9$\ell$ for 3-2G-3S(10,330㎥) type greenhouse with particle size of 27${\mu}{\textrm}{m}$.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.2
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• pp.151-158
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• 2010

In order to measure the deposition velocity of $I_2$ vapor for radish plants and its translocation factor for their roots, radish plants were exposed to $I_2$ vapor for 80 min. at different growth stages between 29 and 53 d after sowing. The exposure was performed in a transparent chamber during the morning time. Deposition velocities ($ms^{-1}$) were on the whole in the range of $1.0{\times}10^{-4}{\sim}2.0{\times}10^{-4}$ showing an increasing tendency with an increase in the biomass density. The results showed some agreement with existing reports that a higher relative humidity would lead to a higher deposition velocity. The acquired deposition velocities were lower than by factors of several tens than some field measurements probably due to a very low wind speed (about $0.2\;ms^{-1}$) in the chamber. Translocation factors (ratio of the total iodine in the roots at harvest to the total plant deposition), estimated in a more or less conservative way, were $1.3{\times}10^{-3}$ for an exposure at 29 d after sowing and $5.0{\times}10^{-3}$ for an exposure at 53 d after sowing. In using the present experimental data, meteorological conditions and chemical and physical forms of iodine need to be carefully considered.

• Membrane Journal
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• v.15 no.1
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• pp.52-61
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• 2005

Permeate flux decline in a microfiltration was analyzed by measuring the permeability of bentonite colloidal solution through polyethylene capillary membranes. The flux decline with time was due to the growth of cake layer on the membrane surface and to the pore blocking by particles. As the time approaches to steady state, the permeate flux is almost controlled by the cake filtration model. Faster flux decline at high trans-membrane pressure was attributed to the formation of denser packed cake layer and pore blocking. The ratio of permeate flux to the initial permeate flux, J/J₁, decreased with increasing the trans-membrane pressure, from 45% for 0.5 kg/sub f//㎠ to 38% for 2.0 kg/sub f//㎠. In comparing the ratio of each fouling component to the total fouling for the 0.5 kg/sub f//㎠ TMP condition, complete blocking was 23.4%, standard blocking was about 14.6% and cake filtration was 62.0%, respectively. Permeate flux through the membrane increases with cross flow velocity, and the effect of the variation of velocity is more significant at 1.0 kg/sub f//㎠ rather than at 2.0 kg/sub f//㎠ of the operation pressure. Permeate flux for the membrane having the average pore diameter of 0.34 ㎛ was higher than that for the membrane of 0.24 ㎛ pore size, with the higher flux with the low concentration of feed. On the operation using the membrane of 0.34 ㎛ pore, the pore blocking in the low concentration of 200 ppm is negligible relative to the pore blocking in the 1000 ppm feed.

• Korean Journal of Materials Research
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• v.9 no.6
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• pp.577-582
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• 1999

In order to make the electroconductive $Si_3N_4$-TiN composities, the Si-Ti(N) compacts were nitrided at $1450^{\circ}C$ for 20hours, and then they were post-sintered by a gas-pressure-sintering technique at 1TEX>$1950^{\circ}C$ for 3.5 hours. As starting powders, commercial si powder of about $10\mu\textrm{m}$, two types of Ti powders of 100 and 325 mesh, and fine-sized TiN of $2.5\mu\textrm{m}$ powders were used. In the $Si_3N_4$-TiN sintered bodies used Ti powders, the relative density and fracture strength and electrical conductivity are low due to the existence of large amounts of coarse pores. However, in the $Si_3N_4$-TiN composite used TiN powder, the fracture toughness, fracture strength and electrical resistivity were $5.0MPa{\cdot}m^{1/2}$, 624MPa and $1400{\omega}cm$, respectively. The dispersion of TiN particles in the composite inhibited the growth of $Si_3N_4$ in the shape of rod and made strong strain field contrasts at the $Si_3N_4$-TiNinterfaces. It was recognized that microstructural control is required to improve the electrical conductivity and mechanical properties of $Si_3N_4$-TiN composites by dispersing TiN particles homogeneously.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1317-1323
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• 2005

Purpose : This study was performed to evaluate the recent frequency of karyotypes in different sex chromosome abnormalities and to evaluate the age and clinical manifestations at diagnosis. Methods : Peripheral blood leukocytes were obtained from subjects who were clinically suspected to have sex chromosome abnormalities and referred to the cytogenetic laboratory in the Department of Pediatrics, Kyungpook National University Hospital from February 1981 to August 2001. Results : The relative frequencies of different sex chromosome abnormalities were Klinefelter(52 percent), Turner(42 percent), XXX syndrome(3 percent) and mixed gonadal dysgenesis(3 percent). The populations of different karyotypes in Klinefelter syndrome were 47,XXY(97 percent) and 46,XY/47,XYY(3 percent). The populations of different karyotypes in Turner syndrome were 45,X(67 percent,), mosaicism(23 percent), and structural aberrations(10 percent). The populations of different karyotypes in XXX syndrome were 47,XXX(67 percent,) and 46,XX/47,XXX(33 percent). All mixed gonadal dysgenesis were 45,X/46,XY. Eighty one percent of sex chromosome abnormalities was diagnosed after puberty. Patients diagnosed with Klinefelter and Turner syndrome in infancy showed nearly normal phenotypes or had minor congenital malformations. Conclusion : Early diagnoses of sex chromosome abnormalities is required to prevent associated morbidities and to maximize growth and development. We have to pay careful attention in diagnoses of Turner syndrome because of the high proportion of mosaicism and structural aberrations.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.823-826
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• 1998

It has been reported that alginic acid hydrolysate retains antimicrobial activity but the enzyme which hydrolyze alginic acid is not developed for industrial use. The authors developed chemical method for hydrolyzing alginic acid. For preparing alginic acid hydrolysate, equal quantity of alginic acid and ascorbic acid were added to water. Then the solution was heated at $121^{\circ}C$ for $20{\sim}30{\;}minutes$. The 4% solution of alginic acid hydrolysate was revealed relative viscosity 1.05, pH 3.2 and opaque whitish-yellow color. By addition of this hydrolysate to nutrient broth with the concentration of 0.1%, the growth of Bacillus sp. isolated from fish meat paste products was inhibited. The fish meat paste products containing 0.3% alginic acid hydrolysate prepared were prolonged their shelf life by 1 day stored at $30^{\circ}C$, 2 days at $20^{\circ}C$ and 4 days at $15^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.466-469
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• 1999

Cladocera are important food organism for seed production of finfishes. freshwater cladocera such as Daphnia and Moina are well known food organisms for the larval rearing of freshwater fishes and are easy for mass culture. However, mass culture technique for marine cladocera are not yet developed, The only mass produced food organisms available these days for the larval production of marine finfishes are rotifer and Artemia. An estuarine cladoceran, Diaphanosoma celebensis, has a high possibility of being used as a food organism for the larval rearing of marine finfishes because this species is much easier to mass culture than marine ones. Therefore many studies are needed for this species. In this study, the effects of the volumes of culture container, 40, 1,500 and 15,000 ml, on the stable production of this species were tested and results are as follow: The maximum densities of this species in each of the culture volumes were reached after 14 days in 40 ml, 12 days in 1,500 ml, and 21 days in 15,000 ml with values of 3.4 $\pm$ 0.4, 14.2 $\pm$ 2.1 and 2.5 $\pm$ 1.6 per ml, respectively. The relative population growth index (RPGI) was stable in the culture volume of 1,500 ml. Moreover, possible harvesting number(individual/ml/day) was much higher in the 1,500 ml container than the other culture volumes. Therefore, optimum culture volume among the tested volumes for mass production of this species was 1,500 ml.