• Advances in concrete construction
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• v.16 no.5
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• pp.255-267
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• 2023

The production of ultra-early-strength concrete (UESC) traditionally involves complexity or necessitates high-temperature curing conditions. However, this study aimed to achieve ultra-early-strength performance solely through room-temperature curing. Experimental results demonstrate that under room-temperature (28℃) curing conditions, the concrete attained compressive strengths of 20 MPa at 4 hours and 69.6 MPa at 24 hours. Additionally, it exhibited a flexural strength of 7.5 MPa after 24 hours. In contrast, conventional concrete typically reaches around 20.6 MPa (3,000 psi) after approximately 28 days, highlighting the rapid strength development of the UESC. This swift attainment of compressive strength represents a significant advancement for engineering purposes. Small amounts of steel fibers (0.5% and 1% by volume, respectively) were added to address potential concrete cracking due to early hydration heat and enhance mechanical properties. This allowed observation of the effects of different volume contents on ultra-early-strength fiber-reinforced concrete (UESFRC). Furthermore, the compressive strength of 0.5% and 1% UESFRC increased by 16.3% and 31.3%, respectively, while the flexural strength increased by 37.1% and 47.9%. Moreover, toughness increased by 58.2 and 69.7 times, respectively. These findings offer an effective solution for future emergency applications in public works.

• Korea journal of population studies
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• v.18 no.2
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• pp.115-168
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• 1995

It is a common wisdom that the long-term economic development of Korea chiefly depends not only on the steady increase of the capital formation but also on the stable increase of the national saving. And also it is a widely accepted opinion that household saving plays a significant role for the smooth supply of investment funds. For the empirical analysis on the determining factors of household saving, consumption function of the household of Korea was utilized indirectly. The reason is that consumption function is regarded as a stable function whereas saving function is considered to be an unstable function of the relevant independent variables. In order to carry out the regression process of the consumption functions, data on the family income and expenditure survey and the farm household economy survey was used. The regression result could be summarized as follows : Firstly, household income and the number of the employed in the household have the negative effect in determining the consumption ratio of the Korean households. On the other hand, ages and the educational attainment of the household heads as well as the number of the household members have the positive effect. During the early part of 21st century, the consumption ratio of the Korean households is expected to be decreased because of the increasing trend of household income, and the ever increasing number of the employed member of the household based on the increasing trend of the labor force participation rate of women and the decrease of the average size of the number of household members owing to widespread nuclear family system. On the other hand, the consumption ratio of the household of Korea is expected to be increased because of the continuous increase of the average ages of the household heads caused by the population aging phenomena and improvement of the educational attainment of the household heads. But on the whole, household saving ratio is expected to be increased owing to the secular downward trend of the consumption and therefore no significant difficulties are anticipated for the smooth provision of investment resources needed to have long-term economic progress of Korea.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1534-1541
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• 2001

Forty-five Large White gilts were used to study the effect of energy intake from 28 to 176 d of age on body composition and reproductive development. From 28 to 60 d, the gilts were fed ad libitum a 16.6 MJ DE/kg, 24% crude protein and 1.3% total lysine diet. From 61 d of age three dietary treatments were used; 1) ad libitum access to feed (15.6 MJ DE/kg, 21% crude protein and 1.07% total lysine) (H), 2) feed offered at 75% (M) of the previous days intake of H, and 3) feed offered at 60% (L) of the previous days intake of H. ADG from 61 to 176 d of age was (p<0.05) affected by treatment. Although live weight at 176 d of age did not differ (p>0.1) the H gilts had higher (p<0.08) carcass weights than the M or L gilts. Back fat depths were similar (p>0.1) for all treatments at 115 d of age, however by 176 d of age M and H gilts were fatter (p<0.1) than L gilts. The mean lipid deposition (LD) from 115 to 176 d of age for L gilts (78.9 g/d) was less (p<0.05) than for M gilts (143.6 g/d) and H gilts (135.6 g/d). There were no differences between treatments for protein deposition (PD) over the same period. More (p<0.05) H gilts (n=8) attained puberty (first observed estrus) than either M gilts or L gilts (n=4 for both). Follicle numbers were similar (p>0.1) across treatments. For gilts that attained puberty, H gilts had fewer (p<0.05) follicles (13.5) than M gilts (19.7) and L gilts (21.3). For gilts with follicular development, H gilts had the heaviest (458.7 g) reproductive tract weight (RTW). However, for those that attained puberty, L gilts had the heaviest RTW. RTW were lowest for those with no follicular development. Energy restriction had a negative impact on puberty attainment, i.e. it took longer to reach puberty. However, for gilts that attained puberty, the number of follicles was greater for those on r feed intakes. It would appear that rate of fat deposition, but not necessarily the total amount of fat, plays an important role in puberty attainment.

• Korea journal of population studies
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• v.16 no.2
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• pp.125-139
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• 1993

Korea has successfully achieved a lowered fertility level owing to the strong population control policy and effective family planning program. Along with fertility decline and decreased number of children in family, average number of household members has decreased and nontraditional households such as one person household and households composed of unrelated individuals have prolifirated, even though the absolute number of them are found minimal in Korea. However in recent years several data and survey results suggest that one person households are gradually in the increasing trend. The study aimed at investigating the real state of one person households in Korea and next analyzing the proportional distribution of one person households by a few socioeconomic characteristics, thus providing basic for eatablishing far-singhted population and social welfare policy in the future. Korea has experienced high growth rate of economy through government-led development plans starting from the 1960s. During the past three decades, Korea has shifted from the agricultural state to the industrialized one. In compliance with the economic growth, urbanization and industrialization have brought about rural-to-urban migration and a great bulk of young population migrated to urban areas, who are seeking for educational and job opportunities. Korean society has also been under drastic change in every aspect of life involving norms, tradition, and attitude, etc. Therefore, in spite of the prejudice on 'living alone' still remaining, young people gradually leave parents and home, and further form nontraditional households in urban areas. Current increase in the number of one person households is partly attributable to the increase in high female educational attainment and female participation in economic activities. As the industrial structure in Korea changes from primary into secondary and tertiary industries, job opportunities for service/sales and manufacturing are opened to young female labor force in the process of industrialization. Contrary to the formation of one person households by young people, the aged single households are composed when children in family leave one by one because of marriage, education, employment. In particular, a higher proportion of aged female single households occur in rural areas due to the mortality difference by sex. Based on the data released form the 1990 Population and Housing Census and National Fertility and Family Health Survey in 1985 and 1991, the study tried to examine the state of one person households in Korea. According to Census data, the number of one person households increased to 1, 021, 000 in 1990, comprising 9.0 percent of total households. And the survey reveal that among total 11, 540 households, 8.0 percent, 923 households, are composed of one person households. Generally, the proportion of female single households is greater than that of male ones, and a big proportion of one person households is concentrated in the 25-34 age bracket in urban areas and 65 years and more in rural areas. It is shown than one person householders in urban areas have higher educational attainment with 59.2 percent high schooling and over in 1991, Job seeking proved to be the main reason for leaving home and forming one person households. The number of young female single households with higher education and economic self-reliance are found nil and the study did not allow to analyze the causal realtionship between female education and employment and one person household formation. However more research and deep analysis on the causal facors on one person household formation using statistical method are believed to be necessary.

• Health Policy and Management
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• v.7 no.1
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• pp.155-182
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• 1997

Objectives : This study was designed to compare North Korea and South Korea in measures of the quality of life (physical quality of life index and human development index) and to investigate the impact of selected medical and socioeconomic factors on PQL variables. Data and Methods : The World Bank, the United Nations Development Programme, and Population Reference Bureau were the principal sources of statistical data of 121 countries. Variables included infant mortality, life expectancy at birth, literacy rate, secondary school enrollment (male and female), GNP per capita, population per doctor, daily calorie supply per capita, and a composite PQL index. The Ordinary Least Square model was employed for cross-countries analysis. Findings : Both countries under quite different political and economic systems saw big improvememts in the quality of life, reducing mortality and prolonging life expectancy during the past three decades. In recent decad, however, North Korea has experienced abrupt exacerbation in the quality of life. Significant improvements in infant mortality of the population wer attributable mainly to GNP per capita and the secondary school enrollemt of female. The principal predictors of life expectancy at birth were population per doctor, infant mortality, and literacy rate. The secondary school enrollment of female and population per doctor were significantly associated with improvements in the physical quality of life index (PQLI). Conclusion : The results of this study confirmed a point illustrated by other studies : The association between quality of life as a measure of health status and socioeconomic factors was strong and positive. The important contribution of educational attainment in general, female education level in particular to improvements in the quality of life deserves good news for building an integrated health care system in the reunified Korea, taking into account the high level of education two koreas are enjoying. Meanwhile, when a sharp drop in the quality of life has been observed in North Korea under serious economic difficulties and food shortage in recent decade, the significant contribution of economic development to improvements in the quality of life poses bad nows for reunifying Korean health care in economic terms.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7713-7720
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• 2015

Background: Colorectal cancer (CRC) is one of the most common cancers. This study aimed to compare the uptake of CRC testing in the general public and in ethnic minorities in Hong Kong. Materials and Methods: This cross-sectional survey covered 2,327 South Asian and Chinese adults aged over 50, recruited from two separate studies. A structured questionnaires were administered by research staff over the telephone or in faceto-face interviews. Results: The uptake rate of CRC testing among South Asians was significantly lower than that of the general population in Hong Kong. Factors associated with the uptake rate were health professional's recommendation, perception of regular visits to doctor, use of complementary therapy, ethnicity, perceived susceptibility to cancer, presence of chronic illness, and education level. In addition, a significant interaction (p<0.05) between ethnicity and health professionals' recommendations was found, after adjustment for the main independent factors identified. Conclusions: Older people with lower educational attainment, without chronic illness and those have lower perceived susceptibility to cancer may be targeted for CRC testing promotion in the society. In addition, health professionals can play a highly influential role in promoting such testing, particularly among ethnic minorities.

• Korean Journal of Materials Research
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• v.9 no.11
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• pp.1055-1061
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• 1999

Indium Tin Oxide (ITO) films were fabricated by vacuum deposition technique and their microwave shielding properties were investigated for the application to the transparent shield material. The vacuum coating was conducted in a RF co-sputtering machine. The film composition and structure associated with the sputtering conditions (argon and oxygen pressure. substrate temperature. RF input power) were investigated for the attainment of high electrical conductivity and good transparency. The electrical conductivity of IT0 films fabricated under the optimum deposition conditions (substrate temperature : $300^{\circ}C$. Ar flow rate : 20 sccm, Oxygen flow rate : 10 sccm, In/Sn input power : 50/30 W) showed 5.6$\times10^4$mho/m. The optical transparency is also considerably good. The microwave shielding properties including the dominant shielding mechanism are investigated from the electrical conductivity, thickness and skin depth of the ITO films. The total shielding effectiveness is then estimated to be 26 dB, which provides a suggestion that the IT0 films can be effectively used as the transparent shield material.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.351-361
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• 2021

This study was conducted to identify the factors of hypertension treatment in Gwangju and to establish a hypertension cure rate management plan by using local community health surveys to provide the hypertension cure rate management plan centering around the wellness local community. The research collected 13,714 Gwangju research data among a total of 685,820 local community health surveys of KDCA (Korea Disease Control and Prevention Agency) from 2017 to 2019. Among the data, 2,941 subjects, those with diagnosed hypertension aged over 30, were selected and analyzed through SAS 9.4, SAS Enterprise Miner 15.1. The results are as follows. The differences in hypertension diagnosis cure rate in Gwangju based on the subjects' socioeconomic characteristics were shown in gender, age, marital status, level of educational attainment, economic activity status, and monthly income. The significant differences in hypertension cure rate based on health behavior characteristics were shown in current smoking, monthly alcohol consumption, high-risk drinking, breakfast, recognition of good health level, diabetes and treatment, annual unmet medical needs, and annual health center use. As a result of the logistic regression analysis and interactive decision tree analysis to identify the factors affecting hypertension treatment, the research found that the factors that appear are age, marital status, diabetes and treatment, and annual unmet medical needs. Accordingly, to increase the recognition of the importance of hypertension treatment to people of young ages and not to develop complications, public health-educational effort in Gwangju is needed with an effective preparation plan.

• Journal of Preventive Medicine and Public Health
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• v.49 no.1
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• pp.69-78
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• 2016

Objectives: The suicide rate in Korea is increasing every year, and is the highest among the Organization for Economic Cooperation and Development countries. Psychiatric patients in particular have a higher risk of suicide than other patients. This study was performed to evaluate determinants of mental health care utilization among individuals at high risk for suicide. Methods: Korea Health Panel data from 2009 to 2011 were used. Subjects were individuals at high risk of suicide who had suicidal ideation, a past history of psychiatric illness, or had utilized outpatient services for a psychiatric disorder associated with suicidal ideation within the past year. The chi-square test and hierarchical logistic regression were used to identify significant determinants of mental health care utilization. Results: The total number of subjects with complete data on the variables in our model was 989. Individuals suffering from three or more chronic diseases used mental health care more frequently. Mental health care utilization was higher in subjects who had middle or high levels of educational attainment, were receiving Medical Aid, or had a large family size. Conclusions: It is important to control risk factors in high-risk groups as part of suicide prevention strategies. The clinical approach, which includes community-based intervention, entails the management of reduction of suicidal risk. Our study identified demographic characteristics that have a significant impact on mental health care utilization and should be considered in the development of suicide prevention strategies. Further studies should examine the effect of mental health care utilization on reducing suicidal ideation.

• Journal of Animal Science and Technology
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• v.59 no.12
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• pp.25.1-25.7
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• 2017

Background: Rabbit breeding with high performance imported ones would be of benefit for genetic diversity and improvement of performance in domestic rabbit breeds. The rearing of more productive rabbit breeds could be pathway to improve the productivity and reduce the production cost. Maternal nutritional status exert a great influence on reproductive functions of does, which may expand from conception, through gestation and parturition and development of kits to puberty. Methods: Four breeds of rabbit were evaluated for their parturition, weaning and pubertal differences among the rabbit population in Ibadan, Nigeria. The breed consist of Fauve De Bourgogne (FDB), Chinchilla (CHA), British Spot (BS) and New Zealand White (NZW) rabbits. A total of 60 bucks and 360 does consisting of 15 bucks and 90 does per breed were mated in 6 mating cycles, three each of natural mating and artificial insemination. All does were synchronized for estrus with 20 IU pregnant mare serum gonadotropin 48 h prior to mating. The does after parturition were assessed for milk yield (g) and kit survival rate (%) till weaning, weight changes of kits from birth to puberty. At puberty, the pubertal age (days) and weight (g) of the offspring were assessed. Result: Results obtained reveals that British Spot doe had highest milk yield among the breeds which significantly increased growth of kit and weight at weaning in British Spot rabbits. Survival rates of Chinchilla kits were significantly (p < 0.05) higher than Fauve de Bourgogne, British Spot and New Zealand White kits. Puberty attainment of the rabbits indicates that British spot does and Fauve de Bourgogne bucks are early maturing. Conclusion: Chinchilla shows high kit survivability and British spot has highest milk yield among the four breeds of rabbit.