• Steel and Composite Structures
• /
• v.21 no.2
• /
• pp.343-356
• /
• 2016

As the common cast-in-place construction works fails to meet the enormous construction demand under rapid economic growth, the development of prefabricated structure instead becomes increasingly promising in China. For the prefabricated structure, its load carrying connection joint play a key role in maintaining the structural integrity. Therefore, a novel end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column was proposed. Under action of low cycle repeated horizontal loadings, comparative tests are conducted on 6 prefabricated pre-stressed intermediate joint specimens and 1 cast-in-place joint specimen to obtain the specimen failure modes, hysteresis curves, skeleton curves, ductility factor, stiffness degradation and energy dissipation capacity and other seismic indicators, and the seismic characteristics of the new-type prefabricated beam-column connecting joint are determined. The test results show that all the specimens for end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column have realized the design objectives of strong column weak beam. The hysteretic curves for specimens are good, indicating desirable ductility and energy dissipation capacity and seismic performances, and the research results provide theoretical basis and technical support for the promotion and application of prefabricated assembly frames in the earthquake zone.

• Asian-Australasian Journal of Animal Sciences
• /
• v.14 no.3
• /
• pp.307-315
• /
• 2001

Litter size has been one of the important economic traits in porcine reproduction. The insulin-like growth factor (IGF) system has been shown to mediate actions of the steroid hormone or to synergize with other endocrine factors so that it consequently plays roles in reproductive processes, including ovulation, implantation, maintenance of pregnancy, and fetal development. However, the effect of the serum IGF system on porcine litter size has not been deeply studied. Therefore, this study was conducted to relate serum IFG-II concentration and IGF binding protein-3 (IGFBP-3) expression with porcine litter size. Moreover, the possible association of those with estrogen receptor (ER) as a candidate gene for litter size was investigated. Swine were separated into two groups showing high and low litter sizes, and sera were collected from sows in the estrous cycle to postnatal growth of their female progeny. Serum IFG-II concentration was measured by radioimmunoassay and IGFBP-3 expression was detected by Western ligand blotting. During the estrous cycle, IGFBP-3 expression in both groups decreased moderately from metestrus to estrus, but IFG-II concentration showed a reverse pattern. Also, IFG-II concentration and IGFBP-3 expression decreased gradually as pregnancy proceeded. Unlike IGFBP-3, IFG-II decreased moderately as newborn pigs grew. Significant differences in serum IFG-II amount between the two groups were detected at 60 (p<0.01), 75, 90, and 105 d (p<0.05) of pregnancy and at 60 (p<0.01), 45, and 105 d (p<0.05) of postnatal growth. Furthermore, based on ER genotypes, a high litter size group with genotypes AB and BB showed lower IFG-II concentration than a low litter size group with a genotype AA during pregnancy. Taken together, the results indicate that the serum IFG-II and IGFBP-3 are correlated with the litter size in pigs.

• Journal of the Korean Society for Railway
• /
• v.11 no.1
• /
• pp.107-113
• /
• 2008

As it recently appears that LCC (Life Cycle Cost) analysis may be considered as an essential method for economic evaluation of infrastructures. Many researches have been made to assess LCC of each facility based on reasonable methods. However, expected maintenance repair cost must be reasonably estimated to enhance the reliability of LCC analysis through systematic and rational methods. This study is intended to propose a rational approach to reliability-based LCC analysis of high-speed railway steel bridges considering lifetime corrosion and fatigue damage. However in Korea, since high speed railway steel bridges are only recently constructed, no direct statistical data are available for the account of the maintenance cost and thus their maintenance characteristics are not clear yet. In this paper, for the assessment of expected maintenance/repair cost, the fatigue system reliability analysis incorporating the corrosion effect is proposed by considering the corrosion and fatigue damage using measured data of high speed railway steel bridges. A model proposed by Rahgozar, of at for fatigue notch factor considering the corrosion effect is used in order to incorporate the corrosion effect into the fatigue strength reduction and S-N curve. Finally, the effectiveness of LCC model proposed for high-speed railway steel bridges is demonstrated by a numerical example.

• KDI Journal of Economic Policy
• /
• v.29 no.1
• /
• pp.177-196
• /
• 2007

This paper investigates the cyclical patterns of buffer capital using an unbalanced panel data for the banks in 30 OECD countries and 7 non-OECD Asian countries. We test whether the relationships between buffer capital and business cycle are systematically different across country groups controlling for other potential determinants of bank capital. We find that the correlation is positive for developed countries while it is negative for Asian developing countries. These findings suggest that, once Basel II is implemented, developing countries are more likely to observe an increase in output volatility. We then review the policy recommendations to mitigate the procyclicality problem of Basel II.

• Journal of IKEEE
• /
• v.14 no.3
• /
• pp.236-243
• /
• 2010

Power quality mitigation devices play an important role in lots of industrial segments. Although there were many devices available in the market, the selection of an appropriate device specially for voltage sags and interruptions mitigation has been a challenge in the utility and customer for several years. It usually depends on technical and economic characteristics of the device. Nevertheless, most mitigation method is selected by rule of thumb or empirical method. In this paper, the life cycle cost analysis for the probabilistic risk assesment of voltage sag mitigation method is performed using either the deterministic or probabilistic approach. The difference between a deterministic and a probabilistic cost analysis approach is illustrated with five different case studies. This paper not only provides a comparison of life cycle costing of various devices but it also indirectly shows the possible savings due to the mitigation of voltage sags in the form of a project balance chart.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.21 no.8
• /
• pp.439-447
• /
• 2009

Cogeneration system produces power as well as heat recovered from waste heat during power generation process. This system has higher energy efficiency than that of the power plant. In this study the optimal design for the cogeneration system with the increase of the capacity considering life cycle cost(LCC) analysis has been performed in the general facilities such as hotels and hospitals under the assumption of electricity cost of 95 won/kWh, the initial cost of cogeneration system of 1,500,000 won!kW and the value of 0.5${\sim}$1.0 in the ratio of heat to power. The optimal ratio of cogeneration capacity divided by average electricity load of facility was found out more than 0.5 in case of electricity cost with the increase of>30%, and the percentage of $CO_2$ reduction was about 9%. The most important factors in the economic analysis of cogeneration system was found out the electrity cost and the initial cost of cogeneration system. Also the ratio of heat to power at the value of>0.5 was not affected in the economy of cogeneration system, but was very important in the $CO_2$ reduction.

• Journal of Korean Academy of Nursing
• /
• v.42 no.4
• /
• pp.496-507
• /
• 2012

Purpose: This study was based on social-role theory, and purposes were to investigate (1) how depression and health determinants vary with married and employed women, and (2) what factors contribute to depression according to family cycle. Methods: A stratified convenience sample of 765 married and employed women was recruited during May to August 2010. Study variables of depression, socio-demographic threatening factors, psycho-stimulating factors, and social-role related factors were measured via a structured questionnaire. Results: Prevalence rate for depression was 18.6%, with highest rate (25.4%) from elementary laborers. Greater levels of depression were related to women's occupation, higher life stress, and poorer health; lower social support and vulnerable personality; higher levels of social-role related stress. From multivariate analysis, women with preadolescents were the most vulnerable to depression affected by occupation, life stress, personality, and parenting stress. These factors (except for occupational class) combined with economic status, social support, and housework unfairness were significant for depression in women with adolescents. Conclusion: Depression among married and employed women differs by psycho-stimulating and social role relevant factors in addition to occupational class and family life cycle. Female elementary laborers and women with children need to have the highest prioritization for community mental health programs.

• Journal of Korea Water Resources Association
• /
• v.51 no.6
• /
• pp.491-501
• /
• 2018

This study presents a systematic framework to derive the best values of design and planning parameters for low impact development (LID) practices. LID was developed to rehabilitate the distorted hydrological cycle due to the rapid urbanization. This study uses Water Management Analysis Module (WMAM) to perform sensitivity analysis and multiple scenario analysis for LID design and planning parameters of Storm Water Management Model (SWMM). This procedure was applied to an urban watershed which have experienced rapid urbanization in recent years. As a result, the design and planning scenario derived by WMAM shows lower total flows and peak flow, and larger infiltration than arbitrary scenarios for LID design and planning parameters. In the future, economic analysis can be added for this application in the field.

• Journal of Labour Economics
• /
• v.27 no.2
• /
• pp.1-27
• /
• 2004

The share of self-employment shows a downward trend until 1990 and then an upward trend since then. The upward trend is mainly due to more employers and more male self-employed, which implies that self-employment plays a significant role as an alternative form of employment. This paper examines whether self-employment can be a bridge between no work and wage work in the processes entering into or exiting labor market, and if so, what determines the choice of self-employment as a bridge, using the data from the Korea Labor and Income Panel Survey(Wave 1 to Wave 5). Empirical analysis employing the probit model shows that the older, female, the less educated, and persons with bad health are more likely to choose self-employment as a bridge in the exit process and that they are less likely to choose it as a bridge in the entry process. Business cycle has a statistically significant negative effect on its role of bridge employment in the exit process but not in the entry process. The result implies that, in the ageing society, labor market policy should consider self-employment as a better alternative than wage work for the aged.

• Journal of Korean Society of Rural Planning
• /
• v.21 no.1
• /
• pp.1-8
• /
• 2015

Population growth and increasing consumption of resources in the process of the industrial development has caused environmental pollution, climate change, and resource exhaustion. Therefore 'sustainable development' has become the important issue for the future. The sustainable development aims at effective resource use, less environmental impacts, and higher social security. Generally the rural area including agricultural fields and forest has various and plentiful natural resources which could make future development sustainable. To develop potential rural resources, the values for energy, environment and economy should be assessed considering the life-cycle of resources. The purposes of this study are to suggest the E3 (Energy, Environment, and Economy) assessment model for rural biomass considering life-cycle of resource and to apply the model to rice, the major agricultural product. As the results of this study, it turned out through E3 assessment that economic gain of rice cultivation is 578,374 won/10a, carbon absorption is $1,530kgCO_2/10a$, carbon emission is $926.65kgCO_2/10a$, and bio-energy potential of by-product is 394,028 kcal/10a. When E3 assessment was applied to by province, the results varied by regions because of the amount of input during cultivation. These results would be useful to realize the rural biomass and design regional resources plan in integrated E3 perspective.