• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.236-237
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• 2014

Recently, it changes to the frame construction in the wall type structure for the life span improvement of the apartment house of our country. The execution of the light panel increased while the execution of the frame construction increased. Therefore, the density and absorption ratio of the magnesium oxide matrix according to the wood flour amount of addition ratio property try to be analyze for the lightweight of the surface material of the light panel. The test result, the density has been declined as the addition ratio increase of the wood flour. In the case of the water absorption ratio, water absorption ratio has been increased as addition ratio increase of wood flour. However, wood flour addition ratio 15% determined the most appropriate when considering the density and water absorption ratio.

• Journal of the Korean Statistical Society
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• v.27 no.4
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• pp.385-396
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• 1998

A computing method of fractional Bayes factor (FBF) for a point null hypothesis is explained. We propose alternative form of FBF that is the product of density ratio and a quantity using the generalized Savage-Dickey density ratio method. When it is difficult to compute the alternative form of FBF analytically, each term of the proposed form can be estimated by MCMC method. Finally, two examples are given.

• Magazine of the Korean Society of Agricultural Engineers
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• v.12 no.1
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• pp.1883-1886
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• 1970

This study was made to obtain the optium compaction of quicklime mixed with soil and to find out the relation of the quicklime mix ratio, dry density and strength by changing the compaction rounds. The obtained results are as follows. 1. The maximun dry density of unmixed soil in not distinguishable, while that of mixed soil is distinguishable. 2. What the increase of quicklime mix ratio, the dry density and strength increase and the optimum quicklime mix ratio could be obtained. 3. With the increase of compaction rounds, the dry density and strength increase, while they decrease in a certain limit and maximum dry density and strength could be obtained.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.4
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• pp.225-234
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• 2014

This study was carried out to investigate the sustainable agriculture of no-tillage technique including recycling of the ridge and the furrow of a field for following crops in Korea. No-tillage systems affect soil physical properties such as three phase (solid, liquid, and air phase) and distribution of soil granular. Solid ratio of subsoil in 3-year of no-tillage (NT) treatment was remarkably lower than that in conventional (CT, 2-year of no-tillage + 1-year of tillage) treatment, while air ratio of subsoil in NT remarkably increased. Bulk density of subsoil in NT remarkably decreased. Porosity of subsoil in NT remarkably increased. Deviation of air phase, bulk density, and porosity of top soil and subsoil in NT remarkably decreased in NT compared with CT. Solid phase ratio and liquid phase ratio in NT and CT had positive (+) correlation. Solid phase ratio and air phase ratio in NT and CT had negative (-) correlation, also liquid phase ratio and air ratio had negative (-) correlation. Bulk density and liquid ratio in soil had positive (+) correlation at top soil and subsoil in NT. Bulk density and air ratio in soil had negative (-) correlation in NT and CT. Porosity and liquid phase ratio had negative (-) correlation, r =1), the significant value was lower in NT than in CT. Porosity and air phase ratio had positive (+) correlation (r =1).

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.5
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• pp.410-416
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• 2021

The initial electrochemical performance of ceramic fuel cell with thin-film electrolyte was evaluated in terms of peak power density ratio, open circuit voltage ratio, and activation/ohmic resistance ratios at 500℃. Hydrogen and air were used as anode fuel and cathode fuel, respectively. The peak power density ratio reduced as ~17% for 40 minutes, which rapidly decreased in the early stage of the performance evaluation but gradually decreased. The open circuit voltage ratio decreased with respect time; however, its time behavior was remarkably different with the reduction behavior of the peak power density ratio. The activation resistance ratio increased as ~15% for 40 minutes, which was almost similar with the time behavior of the peak power density ratio.

• Journal of ILASS-Korea
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• v.4 no.2
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• pp.40-46
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• 1999

Experimental investigation of unsteady impinging diesel spray on the flat plate have been carried out using high speed camera and Malvern system. The density ratios of ambient gas to diesel fuel were varied using $N_2$ and Ar gas in the case of 14.9, 21.2, 28.4, 35.1, 40.4, and 50.1. With the increase of gas density ratio, the radial penetration is decreased due to the resistance of the ambient gas. With the increase of the gas density ratio and the distance between nozzle tip and flat plate, the height of spray is increased due to the entrance and circulation. With the increase of gas density ratio, SMD is decreased on the nearby position at the center of flat plate, but SMD is increased on the far position. As the distance between nozzle tip and flat plate is increased, SMD is always decreased.

• International Journal of Highway Engineering
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• v.17 no.6
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• pp.75-83
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• 2015

PURPOSES : This study deals with the traffic accidents classified by the traffic analysis zone. The purpose is to develop the accident density models by using zonal traffic and socioeconomic data. METHODS : The traffic accident density models are developed through multiple linear regression analysis. In this study, three multiple linear models were developed. The dependent variable was traffic accident density, which is a measure of the relative distribution of traffic accidents. The independent variables were various traffic and socioeconomic variables. CONCLUSIONS : Three traffic accident density models were developed, and all models were statistically significant. Road length, trip production volume, intersections, van ratio, and number of vehicles per person in the transportation-based model were analyzed to be positive to the accident. Residential and commercial area ratio and transportation vulnerability ratio obtained using the socioeconomic-based model were found to affect the accident. The major arterial road ratio, trip production volume, intersection, van ratio, commercial ratio, and number of companies in the integrated model were also found to be related to the accident.

• Journal of Integrative Natural Science
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• v.14 no.3
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• pp.99-106
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• 2021

A mixture of alcohol and water is commonly used as antifreeze, liquor, and the fundamental solvents for the manufacture of cosmetics, pharmaceuticals, and inks in our daily life. Since various properties of alcohol water mixtures such as density, boiling or melting point, viscosity, and dielectric constant are determined by their mixing ratio, it is very important to know the mixing ratio to predict their properties. One of simple method to find the mixing ratio is measuring the density of the mixtures. However, it is not easy to predict the mixing ratio from the density of the mixtures because the relationship between mixing ratio and density has not been established well. The relationship is dependent on the relative sizes of solute and solvent molecules, and their interactions. Recently, an empirical model to predict the density of glycerol water mixture from their mixing ratio has been introduced. The suggested model is simple but quite accurate for glycerol water mixture. In this article, we investigated the applicability of this model to different alcohol water mixtures. Densities for six different alcohol water mixtures containing various alcohols (e.g., ethylene glycol, 1,3-propane diol, propylene glycol, methanol, ethanol, and 1-propanol) were simulated and compared to experimentally measured ones to investigate the applicability of the model proposed for glycerol water mixtures to other alcohol water mixtures. The model predicted the actual density of all alcohol water mixtures tested in this article with high accuracy at various ratios. This model can probably be used to predict the mixing ratio of other alcohol water mixtures from their densities beyond 6 alcohols tested in this article from their densities.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.232-236
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• 2008

This experiment was performed to investigate the effects of two energy levels and four lysine:digestible energy (DE) ratios on the apparent digestibility of nutrients in finishing pigs. The experiment was conducted using a $2{\times}4$ randomized complete block (RCB) design with three replicates. Twenty-four cross-bred finishing barrows ((Landrace${\times}$Yorkshire)${\times}$Duroc) with an average body weight of $64.2{\pm}0.69kg$ were assigned to one of eight treatments. Each barrow was placed in an individual metabolism crate and dietary treatment and water was provided ad libitum. Diets were designed to contain lysine:ME ratios of 1.5, 1.8, 2.1 and 2.4 g/Mcal at 3.35 and 3.6 Mcal/kg of diet in a $4{\times}2$ factorial arrangement. Dry matter (DM), ash, Ca and P digestibility were not affected by energy density or lysine:DE ratios. Crude fat digestibility increased as the energy density increased from 3.35 to 3.6 Mcal of DE/kg. Increasing the lysine:DE ratio also increased crude protein digestibility. There were no interactions between energy density and lysine:DE ratio in terms of nutrient digestibility. Nitrogen excretion via feces was not affected by energy density and lysine:DE ratio, while nitrogen excretion via urine was significantly affected by energy density and lysine:DE ratio. The apparent digestibility of all amino acids except for isoluecine, arginine and aspartic acid as well as average values of essential amino (EAA), non-essential amino acids (NEAA) and total amino acid digestibility (p>0.05) were not affected by energy density. The apparent digestibility of all amino acids except for leucine, proline, alanine and tyrosine, NEAA and total amino acid digestibility were significantly affected by lysine: DE ratio (p<0.05). Interactive effects of energy and lysine:DE ratio also significantly affected amino acid digestibility except for isoleucine, alanine, cystine, leucine, phenylalanine, glutamine and proline (p<0.05). In conclusion, these results suggest that maintaining the appropriate lysine:DE ratio becomes more important as the energy density of the diet increases. Consequently, increasing the lysine:DE ratio can result in increased crude protein digestibility and urinary nitrogen excretion, although apparent protein digestibility and nitrogen excretion were not affected by energy density Furthermore, increasing the lysine:DE ratio also increased the apparent digestibility of essential amino acids, except for leucine, regardless of energy density. The optimum lysine:DE ratio for maximum essential amino acid digestibility of the $64.2{\pm}0.69kg$ pig is approximately 2.4 g of lysine/Mcal of DE.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.5
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• pp.340-346
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• 2021

The initial electrochemical performance of ceramic fuel cell with thin-film electrolyte fabricated by plasma-enhanced atomic layer deposition method was evaluated in terms of peak power density ratio, open circuit voltage ratio, and activation/ohmic resistance ratios at 500℃. Hydrogen and air were used as anode fuel and cathode fuel, respectively. The peak power density ratio reduced as ~52% for 30 min, which continually decreased as time increased but degradation rate gradually decreased. The open circuit voltage ratio decreased with respect time; however, its behavior was evidently different from the reduction behavior of the peak power density. The activation resistance ratio increased as ~127% for 30 min, which was almost similar with the reduction behavior of the peak power density ratio.