• International Journal of Highway Engineering
• /
• v.8 no.1 s.27
• /
• pp.89-98
• /
• 2006

The weight-to-power ratio of the standard truck for the climbing lane design is known to be 200lb/hp. The value was known to be assumed based on constant trucks' capability and regional distributions in stead of widely varied distributions region by region. Additionally, this value was assumed after investigating registered vehicles' statistics instead of investigating real portions of truck volumes. Therefore, it may be said that the value of the current standard truck does not reflect regional or industrial diversity and proportions of truck volumes. To resolve these issues, the present paper studies diversified standard trucks which consider regionally or industrially diversified and observed-volume based weigh-to-power ratios. For this purpose, individual trucks' weigh-to-power ratios obtained at toll-gates of national expressways were used. For regionally based study, the whole nation are divided into 8 regions, then each region is characterized by a unit of a weigh-to-power ratio. The applicability of each value is provided. Results show that the single value for the nationwide standard truck may be 208 lb/hp, 8 lb/hp higher than the current value of 200 lb/hp. Results also show that regional values ranged widely from 170 lb/hp to 230 lb, 30 lb/hp higher/lower than the current value. Conclusively, regional diversity of trucks' weigh-to-power ratios was identified then three types of standardized weigh-to-power ratios which may represent regional characteristics were suggested. As the diversified standard truck are applied to the design standard, two benefits are expected such as decrease of rear-end accident rates or decrease of climb lane construction costs.

• Geomechanics and Engineering
• /
• v.29 no.4
• /
• pp.421-434
• /
• 2022

In the present study, reference samples were prepared using ore preparation facility tailings taken from the copper mine (Kure, Kastamonu), Portland cement (PC) in certain proportions (3 wt%, 5 wt%, 7 wt%, 9wt% and 11 wt%), and water. Then natural zeolite taken from the Bigadic Region was mixed in certain proportions (10 wt%, 20 wt%, 30 wt% and 40 wt%) for each cement ratio, instead of the PC, to prepare zeolite-substituted CPB samples. Thus, the effect of using Zeolite instead of PC on CPB's strength was investigated. The obtained CPB samples were kept in the curing cabinet at a temperature of 25℃ and at least 80% humidity, and they were subjected to the Uniaxial Compressive Strength (UCS) test at the end of the curing periods of 3, 7, 14, 28, 56, and 90 days. Except for the 3 wt% cement ratio, zeolite substitution was observed to increase the compressive strength in all mixtures. Also, the liquefaction risk limit for paste backfill was achieved for all mixtures, and the desired strength limit value (0.7 MPa) was achieved for all mixtures with 28 days of curing time and 7 wt%, 9 wt%, 11 wt% cement ratios and 5% cement - 10% zeolite substituted mixture. Moreover, the limit value (4 MPa) required for use as roof support was obtained only for mixtures with 11% cement - 10% and 20% zeolite content. Generally, zeolite substitution seems to be more effective in early strength (up to 28th day). It has been determined that the long-term strength losses of zeolite-substituted paste backfill mixtures were caused by the reaction of sulfate and hydration products to form secondary gypsum, ettringite, and iron sulfate.

• Asian Pacific Journal of Cancer Prevention
• /
• v.14 no.11
• /
• pp.6899-6903
• /
• 2013

Background: Prevalence is a statistic of primary interest in public health. In the absence of good follow-up facilities, it is difficult to assess the complete prevalence of cancer for a given registry area. Objective: An attempt was here made to arrive at complete prevalence including limited duration prevalence with respect to selected sites of cancer for India by fitting appropriate models to 1, 3 and 5 years cancer survival data available for selected population-based registries. Materials and Methods: Survival data, available for the registries of Bhopal, Chennai, Karunagappally, and Mumbai was pooled to generate survival for breast, cervix, ovary, lung, stomach and mouth cancers. With the available data on survival for 1, 3 and 5 years, a model was fitted and the survival curve was extended beyond 5 years (up to 35 years) for each of the selected sites. This helped in generation of survival proportions by single year and thereby survival of cancer cases. With the help of survival proportions available year-wise and the incidence, prevalence figures were arrived for selected cancer sites and for selected periods. Results: The prevalence to incidence ratio (PI ratio) stabilized after a certain duration for all the cancer sites showing that from the knowledge of incidence, the prevalence can be calculated. The stabilized P/I ratios for the cancer sites of breast, cervix, ovary, stomach, lung, mouth and for life time was observed to be 4.90, 5.33, 2.75, 1.40, 1.37, 4.04 and 3.42 respectively. Conclusions: The validity of the model approach to calculate prevalence could be demonstrated with the help of survival data of Barshi registry for cervix cancer, available for the period 1988-2006.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.28 no.6
• /
• pp.1369-1379
• /
• 1999

To assess the food habits, nutrient intake and diet quality of preschool children aged 1 to 6 in Pusan by their meals and snacks, dietary survey was conducted with 176 subjects by a questionnaire and 24hr recall method. 63.1% of the subjects often skipped meals and 72.1% of those skipped breakfast in the main. 94.5% had snacks over once per day. The mean energy intake was 1406.4kcal, with 57.7% of energy intake being supplied by carbohydrate, 13.7% by protein, 28.6% by fat. 54.9%, 71.7% and 26.5% of intakes of protein, calcium and iron were supplied respectively by animal food. Most of iron intake came from plant origin. The percent of calcium intake from animal origin was low significantly in a group aged 4 to 6(p<0.05). The mean intakes of calcium, iron and niacin of total subjects were below Recommended Dietary Allo wance(RDA) for Koreans. The mean intakes of iron and niacin of a group aged 1 to 3 were below RDA as well as those of energy, caicium, vitamin B2 and niacin of the group aged 4 to 6. For calcium, iron, vitamin A, niacin and vitamin C, proportions of subjects with intake levels less than 75% of RDA were all over 36%. For most nutrients, proportions of subjects with intake levels less than 75% of RDA were higher in the group aged 4 to 6 than in the group aged 1 to 3. Nutrient adequacy ratios(NAR) were the lowest in iron in case of the group aged 1 to 3 and in calcium in case of the group aged 4 to 6. NAR of iron increased and that of vitamin B2 decreased significantly along increase age(p<0.05). The mean adequacy ratios(MAR) were 0.82 for total subjects, 0.83 for the group aged 1 to 3 and 0.80 for the group aged 4 to 6. The indexes of nutritional quality(INQ) of calcium, iron and niacin of the group aged 1 to 3 were below 1 as well as those of calcium, vitamin B2 and niacin of the group aged 4 to 6. Both of the age groups received 31.6~59.0% of daily intakes of energy, fat, calcium, phosphrous, vitamin B2 and vitamin C from snacks. So snacks clearly play an important role in dietary intake. Both of the NARs of most nutrients and MAR were higher in snacks than in three meals. The INQs of calcium and iron from three meals and those of iron, vitamin A, vitamin B1 and niacin from snacks of the group aged 1 to 3 were all below 1. The INQs of calcium and vitamin B2 from three meals and those of vitamin A and niacin from snacks of the group aged 4 to 6 were all below 1. In conclusion, nutritional characteristics were different between the two age groups. More attention should be paid to improve adequacy of nutrient intake through meals. And dietary management for snacks is needed especially in the group aged 1 to 3.

• Journal of Educational Research in Mathematics
• /
• v.27 no.4
• /
• pp.833-855
• /
• 2017

This study aims to reinvestigate the reason for introducing radian as a new unit to express the size of angles, what is the meaning of radian measures to use arc lengths as angle measures, and why is the domain of trigonometric functions expanded to real numbers for expressing general angles. For this purpose, it was conducted historical, mathematical and applied mathematical analyzes in order to research at multidisciplinary analysis of the radian concept. As a result, the following were revealed. First, radian measure is intrinsic essence in angle measure. The radian is itself, and theoretical absolute unit. The radian makes trigonometric functions as real functions. Second, radians should be aware of invariance through covariance of ratios and proportions in concentric circles. The orthogonality between cosine and sine gives a crucial inevitability to the radian. It should be aware that radian is the simplest standards for measuring the length of arcs by the length of radius. It can find the connection with sexadecimal method using the division strategy. Third, I revealed the necessity by distinction between angle and angle measure. It needs justification for omission of radians and multiplication relationship strategy between arc and radius. The didactical suggestions derived by these can reveal the usefulness and value of the radian concept and can contribute to the substantive teaching of radian measure.

• Journal of the Korean Applied Science and Technology
• /
• v.1 no.1
• /
• pp.49-55
• /
• 1984

The lipid and fatty acid compositions and vitamin E content were analyzed in 48 human mature milk, 3 infant formulas (modified milk powder) and 8 market milk samples. The total lipid content in modified milk powder was similar those in human milk and market milk when total solids content of modified milk powder was corrected to that of human milk. In comparison with human milk, modified milk powder contained a lower proportion of triglycerides and higher proportions of phospholipids, free fatty acids and cholesterol esters. The ratios of phospholipids/triglycerides, total cholesterol / triglycerides and total tocopherol/total lipids in modified milk powder were significantly higher than those in human milk and market milk. The American recommendation for linoleic acid (0.7 IU/g) could be satisfied with human milk, modified milk powder and market milk. The proportions of short- and medium-chain even numbered saturates were higher and the proportions of long-chain derivatives of linoleic (${\omega}6$ series) and linolenic (${\omega}3$ series)acids were lower in modified milk powder and market milk than in human milk. It is concluded that in view of their levels in breast milk, the polyenoic derivatives of linoleic and linolenic acids must be taken into account when assessing infant foods.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.49 no.4
• /
• pp.51-59
• /
• 2007

Recently, concrete has been made porous and used for sound absorption, water permeation, vegetation and water purification according to void characteristics. Many studies are carried out on the utilization of sewage sludge, fly ash and waste concrete to reduce the environmental load. This study was performed to evaluate the void, strength, relationship between void and strength, permeability and chemical resistance properties of porous polymer concrete for pavement with different fillers. An unsaturated polyester resin was used as a binder, crushed stone and natural sand were used as an aggregate and bottom ash, fly ash and blast furnace slag were used as fillers. The mix proportions were determined to satisfy the requirement for the permeability coefficient, $1{\times}10^{-2}$ cm/s for general permeable cement concrete pavement in Korea. The void ratios of porous polymer concrete with fillers were in the range of $18{\sim}23%$. The compressive strength and flexural load of porous polymer concrete with fillers were in the range of $19{\sim}22$ MPa and $18{\sim}24$ KN, respectively. The permeability coefficients of porous polymer concrete with fillers were in the range of $5.5{\times}10^{-1}{\sim}9.7{\times}10^{-2}$ cm/s. At the sulfuric acid resistance, the weight reduction ratios of porous polymer concrete immersed during 8-week in 5% $H_{2}SO_{4}$ were in the range of $1.08{\sim}3.56%$.

• Journal of Korean Society on Water Environment
• /
• v.28 no.1
• /
• pp.115-120
• /
• 2012

Different colloidal particles generally co-exist in the water and wastewater. Thus, there needs to identify practical electrokinetic characteristics of the particles, comparing with the case when each colloidal material is independently distributed. In this study, changes of overall zeta potential was examined through mixed dispersions of $TiO_{2}$ and $MnO_{2}$. The mixing ratios were classified into 3-type in order to distinguish the effects of the proportions of each particle from those of total concentration in colloidal suspensions. The types are single colloidal dispersions of $TiO_{2}$ and $MnO_{2}$ (1:0, 0:1), mixed dispersions at different ratios (0.75:0.25, 0.5:0.5, 0.25:0.75), and a mixed dispersion with doubled concentration (1:1), respectively. It showed that the overall variation of zeta potential as a function of pH was intensified in a colloidal dispersion with the ratio of 1:1. It was concerned that the double action of ion would contribute to this result. On the one hand, the zeta potentials of each colloidal dispersion commonly decreased at the state of strong acid and base under the influence of compression of the electric double layer. The changing patterns were also considered through calculating total interaction energy between colloidal particles based on DLVO theory and measuring turbidity of the colloidal dispersions.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.7 no.3
• /
• pp.202-209
• /
• 2019

The objective of this study is to examine the reproducibility for compressive strength development and mechanical properties of lightweight concrete made using bottom ash aggregates and foam(LWC-BF). Based on the mix proportions conducted by Ji et al., six identical mixes were prepared with different actual foam volume ratios from 0% to 25% and water-to-binder ratios from 25% to 30%. The presently measured properties, including initial slump, slurry density, compressive strength gains at different ages, splitting tensile strength, and modulus of rupture, were very close to those determined in the previous tests by Ji et al. Thus, the developed LWC-BF has a good potential in obtaining a reproducibility for compressive strength development and mechanical properties even though the troubles of mixing control owing to the addition of preformed foam.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.1073-1076
• /
• 2008

This study shows some results of concrete mixing design has 100 years life time. The ratios of ternary blended cement are 4 types. the ratios of blast furnace slag cement are 3 types. In this case study, 40%, 50% and 60% replacement ratio of blast furnace slag(BSF) to OPC are used, also 35:45:20, 30:35:35, 30:40:30 and 35:40:25 ratio of OPC:BSF:FA are used. The mixing design tests include slump, air content, compressive strength and thermal properties of concrete. The compressive strength tests are executed at the age of 3, 7, 28, 56, and 91 days. The coefficient of chloride diffusion is determined by NT Build 492 method. The purpose of this study is to shows the results of case studies as the ratio of blended cement varies.