• Computers and Concrete
• /
• v.3 no.5
• /
• pp.357-373
• /
• 2006

The concepts of four parameters of nominal water-cement ratio, equivalent water-cement ratio, average paste thickness, fly ash-binder ratio were introduced. It was verified that the four parameters and the mix proportion of mortar can be transformed each other. The behaviors (strength, workability, et al.) of mortar primarily determined by the mix proportion of mortar now depend on the four parameters. The prediction models of strength and workability of mortar were built based on artificial neural networks (ANNs). The calculation models of average paste thickness and equivalent water-cement ratio of mortar can be obtained by the reversal deduction of the two prediction models, respectively. A mortar mix proportion design algorithm was proposed. The proposed mortar mix proportion design algorithm is expected to reduce the number of trial and error, save cost, laborers and time.

• Journal of the Korea Concrete Institute
• /
• v.12 no.5
• /
• pp.25-34
• /
• 2000

When concrete is placed underwater, it is diluted with separating cementitious material and as a result the quality of concrete becomes poor. To solve this problem, antiwashout underwater concrete is increasingly used for the construction and repair of the concrete structure underwater. The objective of this study is to investigate the characteristics of antiwashout underwater concrete as to the mix proportion, casting and curing water through experimental researches. The unit weight of water and cement, water-cement ratio, fine aggregate ratio, unit weight of antiwashout underwater agent and superplasticizer, and casting and curing water were chosen to measure the suspended solids, pH, air contents, slump flow, unit weight of hardened concrete, and compressive strength. From this study, the incremental modulus at mix proportion design and unit weight of antiwashout underwater agent were increased more than fresh water, and it is a optimum mix proportion that the unit weight of water(and cement) is 230kg/$\textrm{m}^3$(460kg/$\textrm{m}^3$), waterOcement ratio is 50%, fine aggregate ratio is 40%, unit weight of antiwashout underwater agent is 1.2% of water contents per unit weight of concrete, and unit weight of supeplasticizer is 2.5% of cement contents per unit weight of concrete when the antiwashout underwater concrete is used for the underwater work of ocean.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.50 no.5
• /
• pp.39-50
• /
• 2008

This study are decided the mix proportion method of latex modified concrete for agricultural concrete structures from the results of workability and strength test with mix proportion factor. For mix proportion factor, this study are selected the water-cement ratio, unit cement amount and latex content. Also, this study were performed the slump, compressive strength test and microstructure analysis using the scanning electron microscope(SEM). The strength and slump of LMC are dependent with unit cement amount, latex content, and water-cement ratio. Especially, the strength of LMC are not controlled by single mix proportion factor but effected by combined mix proportion factor. Microstructure investigation are showed the LMC are reduced the internal pore volume and enhanced the transition zone between cement paste and aggregate interface. This effect get by consist of latex films in the concrete. Also, this study were recommended the mix proportion method for LMC. These mix proportions method are estimated the mix design for satisfied the target performance which are applied the agricultural concrete structure.

• Journal of the East Asian Society of Dietary Life
• /
• v.8 no.2
• /
• pp.155-161
• /
• 1998

Response surface methodology (RSM) was used for optimizing preparation conditions and monitoring the quality of buckwheat mook prepared using buckwheat starch. The textures(hardness, adhesiveness, cohesiveness and gumminess) of buckwheat mook were decreased in inverse proportion to the increase of water content. the L and b values of Hunter color parameters in buckwheat mook were increased in proportion to the increase of water content. However, The a value of Hunter color parameters of buckwheat mook were decreased in inverse proportion to the increase of water content. Organoleptic properties(color, form, taste and mouth-feel) of buckwheat mook showed a maximum score in 700ml(water content), 14min(gelatinization time)

• Journal of the Korea Concrete Institute
• /
• v.12 no.6
• /
• pp.91-98
• /
• 2000

Porous concrete having continuous voids is gaining more interest as an ecological material. It has several useful functions such as water and air permeability, sound absorption, etc. Its strengths are considerably lower than those of conventional concrete due to the large and continuous voids in it. This study has been carried out to investigate the influence of mix factors and mixture proportion of aggregate on the strengths and water permeability of porous concrete. And it has been carried out to investigate the evaluation of void of porous concrete by the ultra-sonic pulse velocity. The results f this study are as follows: 1) The theoretical void ratio has greater influence than any other factor on the strengths and water permeability of porous concrete. And it is a little affected by the replacement proportion of silica-fume and mixture proportion of aggregate. 2) Because the coefficients of correlation between the void ratio and ultra-sonic pulse velocity were relatively high, it will be possible that the void ratio is predicted by the ultra-sonic pulse velocity.

• Journal of Nutrition and Health
• /
• v.19 no.1
• /
• pp.66-73
• /
• 1986

This study was undertaken to investigate the effects of age and of the dietary protein sources & levels on urinary calcium excretion and bone metabolism in the rats. Two experiments were conducted . In experiment U, 6& 20 weeks old rats were fed 8 & 36%, casein & ffish protein diet for 5 weeks . In experiment II, 16& 52 weeks old rats were fed 40 % protein diets, protein sources were casein, fish and gluten. High-protein diet group excreted more caldium in urine than low-protein group. Urinary calcium excretion was affected by the sources of protein ; gluten group excreted more Ca, followed by fish & casein group. Total bone Ca & Ca proportion in ash were higher in 20 weeks old rats than 6 weeks old rats, but 16 & 52 weeks old rats showed no differences. bone composition showed that water proportion was high and ash proportion was low in 6 weeks old rats than in 20 weeks old rats. However, these tendencies were not observed between 16 weeks and 52 weeks old rats. And bone composition was affected by protein sources ; higher ash proportions were noted in one order of casein, fish, and gluten water proportion were lower in one same order.

• Proceedings of the Korean Environmental Health Society Conference
• /
• 2004.12a
• /
• pp.8-11
• /
• 2004

Objective To know about hygienic condition of drinking water in rural area of Kunming. Methods Selected 4 counties with different economy to investigate. In every county, according to the proportion, 10 drinking water spots were selected by randomization of lift drinking water'. Results In 4 areas, surface water for drinking is 82.41%, under water is 17.59%. And concentrated supply is 83.02% by populated proportion, others are 16.98%. 40 specimens qualification rate is 47.50%, and in it concentrated supply is 87.50%, others are 19.05%. Conclusion Unhealthy drinking water exist in most testing counties. Mainly microorganism isn't qualified. Concentrated management in drinking water is batter than other ways.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.2
• /
• pp.149-161
• /
• 2016

Fishing characteristics of Korean tuna purse seine fishery in the Pacific Ocean were investigated using logbook data compiled from captain onboard and the statistical data from 1980 to 2014. Changes in fishing ground and correlation between marine environmental factors and fishing patterns were investigated using Oceanographic index. The proportion of unassociated set was higher than that of associated set. The catch proportion of yellowfin was higher in the unassociated set, while that of skipjack and bigeye was higher in the associated set. Due to vessels, fishing gears and Korean captains' high-level of skills in fishing technology optimized for the unassociated set and preference of large fishes, especially large yellowfin tuna, it showed unique fishing characteristics focusing on the unassociated set. As for fishing distributions of Korean tuna purse seine fishery and impacts of oceanographic conditions on the fishery, the main fishing ground was concentrated on the area of $5^{\circ}N{\sim}10^{\circ}S$, $140^{\circ}E{\sim}180^{\circ}$ through the decades. When stronger El-nino occurred, the range of fishing ground tended to expand and main fishing ground moved to the eastern part of western and central Pacific Ocean. During this season, yellowfin tuna had high CPUE and catch proportion of yellowfin tuna in the eastern part also increased. As for the proportion of fishing effort by set type, proportion of log associated set was high during El-nino season while that of FAD associated set was high during La-nina season.

• Journal of the Korean Statistical Society
• /
• v.31 no.3
• /
• pp.405-413
• /
• 2002

We consider a finite dam with general inputs and adopt the level crossing approach to obtain explicit formulas of the expected wet period, the expected loss of water due to overflows in a wet period, and the long-run proportion of loss in inputed water.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10a
• /
• pp.373-378
• /
• 2000

The objective of this study was to investigate the influence the influence of theoretical void ratio(T.V.R), grading of aggregate and curing method on the strength and water permeability of porous concrete, and the reduction proportion of water permeability by these factors. The results of the study showed that its strength and water permeability were greatly depended on the T.V.R and grading of aggregate, but didn't on the curing method. And, when the T.V.R and grading of aggregate were increased, the reduction proportion of water permeability was small. As the relation ship between its physical properties and non-destruction test values was very high, its use for the estimation of the physical properties will be useful.