• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.40 no.3
• /
• pp.214-224
• /
• 2004

A large cage system for the purpose of fishes farming in the open sea was influenced by various forces from the ocean environment. The deformation of the cage by these forces affects the safety of the cage itself, as well as that of the cultivated creatures. In this research, theoretical model was established to analyzing dynamic movement influenced by current for cage. Also, to increase the accuracy of calculations, the reduction ratio of flow speed acquired using the flume tank experiment. Applying the reduction ratio of flow speed to the numerical calculation, the calculation values were compared with the measured values in the flume tank experiment using cage model. The results were as follows ; 1. When the flow speed of the flume tank is fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of porosity ratio of netting. 2. When the porosity ratio is fixed, the increase of the velocity of flow which is passed the upper panel side is proportion to the increase of velocity of flow. 3. When the porosity ratio and the flow speed of the flume tank are fixed, the decrease of the velocity of flow which is passed the upper panel side is proportion to the increase of attack angle. 4. As a result of comparison between the underwater shape by simulation which is applying the reduction ratio of flow speed from the experiment using plane netting and that by model experiment, it was found out that the result of the simulation was very close to that of model gear within ${\pm}$ 5 % error range.

• Journal of Environmental Science International
• /
• v.20 no.1
• /
• pp.71-79
• /
• 2011

In this study, a series of soil concrete mixtures were tested for the compressive strength according to ratio of aggregate to binder, compaction energy, maximum aggregate size, ratio of silica fume to cement, and ratio of water to binder. The optimum mixing ratio of soil concrete mixtures composed of volcaniclastic, cement, silica fume, concrete polymer and water were analysed. The test results for optimum proportion were as follows ; (1)ratio of aggregate to binder was 4 : 1, (2)compaction energy level was level 2, (3)maximum aggregate size was 13 mm, (4)ratio of silica fume to cement was 10%, (5)ratio of water to binder was 25%. Also, dry type construction techniques were applied using the optimum soil concrete mixture. From the results of this study, the compressive strength of soil concrete and construction techniques were suitable for making eco-friendly soil pavement.

• Journal of the Korea Concrete Institute
• /
• v.17 no.2 s.86
• /
• pp.293-302
• /
• 2005

This study describes data from determination of the optimum mix proportion and site application of the mass concrete placed in bottom slab and side wall having a large depth and section as main structures of LNG in-ground tank. This concrete requires low heat hydration, excellent balance between workability and consistency because concreting work of LNG in-ground tank is usually classified by under-pumping, adaptation of longer vertical and horizontal pumping line than ordinary pumping condition. For this purpose, low heat Portland cement and lime stone powder as cementitious materials are selected and design factors including unit cement and water content, water-binder ratio, fine aggregate ratio and adiabatic temperature rising are tested in the laboratory and batch plant. As experimental results, the optimum unit cement and water content are selected under $270kg/m^3$ and $l55{\~}l60 kg/m^3$ separately to control adiabatic temperature rising below $30^{\circ}C$ and to improve properties of the fresh and hardened concrete. Also, considering test results of the confined water ratio($\beta$p) and deformable coefficient(Ep), $30\%$ of lime stone powder by cement weight is selected as the optimum replacement ratio. After mix proportions of 5cases are tested and compared the adiabatic temperature rising($Q^{\infty}$, r), tensile and compressive strength, modulus of elasticity, teases satisfied with the required performances are chosen as the optimum mix design proportions of the side wall and bottom slab concrete. $Q^{\infty}$ and r are proved smaller than those of another project. Before application in the site, properties of the fresh concrete and actual mixing time by its ampere load are checked in the batch plant. Based on the results of this study, the optimum mix proportions of the massive concrete are applied successfully to the bottom slab and side wall in LNG in-ground tank.

• Geomechanics and Engineering
• /
• v.33 no.6
• /
• pp.553-565
• /
• 2023

As the structure of broken rock mass is complex, with obvious discontinuity and anisotropy, it is generally necessary to reinforce broken rock mass using grouting in underground construction. The purpose of this study is to experimentally investigate the mechanical properties of broken rock mass after grouting reinforcement with consideration of the characteristics of broken rock mass (i.e., degree of fragmentation and shape) and a range of reinforcement methods such as relative strength ratio between the broken rock mass and cement-based grout stone body (λ), and volumetric block proportion (VBP) representing the volumetric ratio of broken rock mass and the overall cement grout-broken rock mass mixture after the reinforcement. The experimental results show that the strength and deformation of the reinforced broken rock mass is largely determined by relative strength ratio (λ) and VBP. In addition, the enhancement in compressive strength by grouting is more obvious for broken rock mass with spherical shape under a relatively high strength ratio (e.g., λ=2.0), whereas the shape of rock mass has little influence when the strength ratio is low (e.g., λ=0.1). Importantly, the results indicate that columnar splitting failure and inclined shear failure are two typical failure modes of broken rock mass with grouting reinforcement.

• Fashion & Textile Research Journal
• /
• v.12 no.4
• /
• pp.487-493
• /
• 2010

The objectives of this study were to investigate the progress of obesity in women from childhood to adulthood and to analyze the characteristics of obese figures through comparing their body proportions to normal-weight people, to provide a basic reference for development of new size categories and improved pattern grading. Body measurement was made on 6,704 women age between 7-39 in Sizekorea 2004 database. The age range was divided into three groups: children(7-12), teenagers(13-18) and adults(19-39). The result of research into the characteristics of body proportions of obese figures and the classification of different figure groups of obese people are as follows: The ratio between width and circumference for each part of the body was investigated according to body weight which was grouped into three different weights of low, normal and obese body weights. And the result demonstrated that in all the ranges of age, the obese groups had the lowest ratio between width and circumference, having a thick body shape. And according to the result of comparing the ratio of the circumference of each body part divided by the waist circumference, the obese group also showed a low ratio, indicating that they have bigger waist circumference than any other body parts. By analyzing the ratio of circumference of body parts divided by waist circumference, three factors were identified as contributing to obesity. Using the factor loadings of the upper, distal and lower body obesity, a cluster analysis was carried out and three different categories of obesity were defined; abdominal obesity, distal obesity and proximal obesity.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.33 no.8
• /
• pp.1306-1314
• /
• 2009

This study investigates the progress of obesity in men from childhood to adulthood, by analyzing the measurement references from the 5th Size Korea. It also seeks to analyze the characteristics of obese figures through the comparison of body proportions to normal-weight people, to provide a basic reference for the development of new size categories and improved pattern grading. The age range is divided into three groups: children (2-7), teenagers (13-18), and adults (19-39). The results of research into the characteristics of body proportions of obese figures and the classification of different figure groups of obese people are as follows. The ratio between width and circumference for each part of the body was investigated according to body weight that was grouped into three different categories of low, normal, and obese body weights. The result demonstrated that in all the ranges of age, the obese groups had the lowest ratio between width and circumference in having a thick body shape. According to the results that compared the ratio of the circumference of each body part divided by the waist circumference, the obese group showed a low ratio that indicates that they have a bigger waist circumference than other parts of the body. Two factors are identified as contributing to obesity in analyzing the ratio of the circumference of body parts divided by waist circumference. Using the factor loadings of the upper and lower body obesity, a cluster analysis was carried out and three different categories of obesity were defined; lower body obesity, abdominal obesity, and upper body obesity. The obese groups of children and teenagers were mostly in body shape with lower obesity and abdominal obesity, whereas the adults group showed the obesity present in the upper body obesity that have fewer cases in lower body obesity.

• Journal of Elementary Mathematics Education in Korea
• /
• v.19 no.4
• /
• pp.485-499
• /
• 2015

In this paper, focusing on definitions of terms related to ratio (a:b, external ratio, internal ratio, percentage, proportion, bi-ui-gap(value of a:b)), elementary school mathematics textbooks of Korea and Japan are compared. We can find significant differences between Korean and Japanese textbooks. In Korean textbook, 'bi-yul' includes both of the internal ratio and the external ratio. In Japanese textbooks, the external ratio(amount of unit size) and the internal ratio(wariai) are defined independently. And a:b is set to a subconcept of the internal ratio. In addition, a:b and percentage are presented as methods to express the internal ratio. From these results, the following four implications for developing our mathematics textbooks can be presented as conclusions. First, it is necessary to limit the ratio to mean the internal ratio. Second, it is necessary to define connotatively the ratio as the internal ratio and to set it as a prior concept of a:b. Third, it is necessary to define 1% as the internal ratio 0.01. Fourth, it is necessary to define bi-ui-gap as a number for expressing a:b, when viewing a:b as the expression method of the internal ratio.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2002.05a
• /
• pp.69-74
• /
• 2002

The following results are achieved from a mortar flow test depending on stainless steel slag fineness, replacement ratio, and a research on material age compressive strength, strength activity index. 1. Flow is proportional to the stainless steel slag fineness within the limits of 4000~8000$\textrm{cm}^2$/g, but in the case of fineness 20000$\textrm{cm}^2$/g flow decreases at all conditions except the case of replacement ratio 10%. 2. As stainless steel slag replacement ratio increases, Mortar of flow somewhat decreases. 3. As stainless steel slag blends, compressive strength decreases, but in proportion to the increase of age, compressive strength increases. 4. As stainless steel slag replacement ratio, compressive strength decreases. 5. In the case of stainless steel slag fineness 6000$\textrm{cm}^2$/g and 20.000$\textrm{cm}^2$/g, compressive strength of revelation ratio has the maximum value when it's replacement ratio is 10%.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.2 no.1
• /
• pp.113-119
• /
• 2006

It is now established that more than two types of blended aggregate have beneficial effects on quality and supply of concrete in the long run. However, studies on blended aggregate have not widely been progressive and the evaluation method of its most favorable mixture proportion is still needed. Therefore this study investigated the most favorable mixture proportion through the physical experiment of fresh and hardened state's cement mortar, in response to three types of composite ratio, natural fine aggregate(Ns), crushed fine aggregate(Cs) and recycled fine aggregate(Rs). Test showed that increase of blending ratio of Ns and Cs improved fluidity of mot1ar. For the properties of compressive and flexural strength, mortar blending Ns and Cs properly, exhibited similar value to one using only Cs, while mortar mixing Rs showed lower strength value as less as 6% of control one. Mortar using only Rs exhibited the largest drying shrinkage value. In addition, even thought it is not a clear quantitative analysis, technical-imaging-skill presenting the most favorable mixture proportion 3-dimensionally is proposed in this research, in order to notify the proportion easily.

• The Journal of the Convergence on Culture Technology
• /
• v.10 no.1
• /
• pp.153-158
• /
• 2024

Recently, concerns about the spread of credit risk in China's real estate market are gradually increasing. Therefore, it is very meaningful to diagnose the management stability of Chinese commercial banks. This study analyzes the impact of housing prices on the loan proportion and management stability of Chinese commercial banks. In addition, we classify Chinese commercial banks according to size and verify whether there are differences in loan proportion and management stability. If there is a difference by scale, the effect of interaction with housing price changes is also verified. The analysis results are summarized as follows. First, it was found that as the housing price growth rate increases, the proportion of loans from Chinese commercial banks increases. Second, as the rate of increase in housing prices and the proportion of total loans increases, management stability appears to decrease. Third, larger banks were found to have a higher proportion of loans, and smaller banks were found to have greater management stability. The results of this analysis show that Chinese commercial banks' aggressive expansion of their loan proportion is lowering their management stability. Therefore, it is necessary to adjust the loan ratio to the appropriate size level and secure stability with differentiated strategies according to the loan ratio