• Proceeding of EDISON Challenge
• /
• 2016.03a
• /
• pp.222-227
• /
• 2016

In this paper, the optimized design for bow structure was investigated by using EDISON software. Considering the mechanism of the bow, non-linear FEM analysis was essential. The factors of the design are height, width, number of holes and taper value. High performance of the internal energy and lowest mass were main issues. The limit of the von-mises stress was yield strength for the material. Material was chosen by considering typical bow material, Aluminum. Using Taguchi method($L_9$), 9 models were selected and contribution rate was calculated for each factors. Following the contribution rate, 3 factors were fixed and optimized model was predicted. After making optimized model for FEM analysis, the value of internal-energy, mass for FEM model were compared with predicted value, calculated the percentage error and figure out the reliability of Taguchi method.

• Environmental and Resource Economics Review
• /
• v.31 no.4
• /
• pp.865-885
• /
• 2022

Korean government updated her Nationally Determined Contribution (NDC) in 2021 and announced the target and various measures for reductions. Among the many issues, final energy demand and renewable energy power mix for 17 provinces to achieve the target are being analyzed using GCAM-Korea. Simulation results show that final energy demand of 2030 is approximated at the similar level to that of 2018. This is being enabled by the conservation of coal with higher electrification especially in industry sector. Higher power demand with lower coal consumption in final energy consumption is shown to be provided by 33.1% of renewable, 24.6% of gas, and 18.0% of nuclear power generation in 2030. Meanwhile, the share of coal-fired power generation is expected to be reduced to 12.8%. Major future power provider becomes Gyeongbuk (Nuclear), Gyeonggi (Gas), Jeonnam (Nuclear, Gas) and Gangwon (PV, Wind), compared to one of current major power provider Chungnam (Coal). This analysis is expected to provide a useful insight toward the national and provincial energy and climate change policy.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.272-274
• /
• 2002

The contribution of light in high-energy film dosimetry was examined using six commercially available solid water substitute phantoms. As six commercially available phantoms; RMI-451, Mix-DP, WE211, WE211-Black, PMMA and PMMA Black were evaluated in this study. It is difficult to evaluate the contribution of Cerenkov radiation and the optical permeability to the relative and/or absolute dosimetry using unpacked film in these phantoms. Therefore the contribution of Cerenkov radiation was estimated by the comparison between film densities in the shielded side (shutting off the light) and unshielded sides on a phantom. The effect of optical permeability was measured under ambient light by the time scale method. The results suggest that the use of black colored phantoms may improve the accuracy of dose measurement in film dosimetry.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 2003.11a
• /
• pp.337-342
• /
• 2003

• Journal of the Korean Solar Energy Society
• /
• v.31 no.1
• /
• pp.100-106
• /
• 2011

This study proposes a $CO_2$ emission reduction method through correlation analysis of a sample building. First, energy saving factors of heating, cooling, lighting were determined for the correlation analysis and $CO_2$ emission contribution rate of the design parameters have been analyzed. Then optimal combination of each design parameter has been drawn. Heat transfer coefficient of walls and windows, air permeability, windows area ratio, and shading devices were selected as applicable energy saving factors of the sample building. Also computer simulation was conducted using experimental design by Orthogonal Arrays of the statistical method. And the contribution rate was estimated by Analysis of Variance-ANOVA. As a result, the $CO_2$ emission in heating was reduced to 51.9%; in cooling to 16.8%; and in lighting to 2% compared to the existing building. The majority of the reduction was presented by heating energy.

• Korean Circulation Journal
• /
• v.52 no.1
• /
• pp.60-70
• /
• 2022

Background and Objectives: There is growing evidence supporting the association between ultra-processed food (UPF) consumption and metabolic disease risk. However, little is known about the association between UPF consumption and blood pressure (BP). Thus, this study examined the association between UPF consumption and elevated BP in Korean adults. Methods: This study used data from the Korea National Health and Nutrition Examination Survey (2016-2018) and included 9,188 participants aged 30-79 years without a history of hypertension diagnosis. Food items reported in a one-day 24-hour recall were categorized on the basis of the NOVA (not an acronym) food classification criteria. UPF consumption was estimated as the contribution to total energy intake. Elevated BP was defined as systolic BP ≥120 mmHg or diastolic BP ≥80 mmHg. The independent association between UPF consumption and elevated BP was assessed by multivariable logistic regression analysis. Results: The upper tertile of UPF consumption was significantly associated with elevated BP compared with the lower tertile, after adjusting for potential confounders. A linear trend was observed for elevated BP across the tertiles of the dietary energy contribution of UPF. Similar results were found in stratified analyses by age group, smoking, obesity, and overall dietary quality. However, a marginal level of association was found in some subgroups, current smokers, and non-obese adults. Conclusions: The dietary energy contribution of UPF consumption was positively associated with increased prevalence of elevated BP, and these findings suggest that lowering UPF consumption might help prevent BP elevation.

• Earthquakes and Structures
• /
• v.23 no.3
• /
• pp.271-282
• /
• 2022

Seismic resisting self-centering bridge piers with high energy dissipation and negligible residual displacement after an earthquake event are focus topics of current structural engineering. The energy dissipation components of typical bridge piers are often relatively single; and exhibit a certain level of damage under earthquakes, leading to large residual displacements and low cumulative energy dissipation. In this paper, a novel socket self-centering bridge pier with a hybrid energy dissipation system is proposed. The seismic resilience of bridge piers can be improved through the rational design of annular grooves and rubber cushions. The seismic response was evaluated through the finite element method. The effects of rubber cushion thickness, annular groove depth, axial compression ratio, and lateral strength contribution ratio of rubber cushion on the seismic behavior of bridge piers are systematically studied. The results show that the annular groove depth has the greatest influence on the seismic performance of the bridge pier. Especially, the lateral strength contribution ratio of the rubber cushion mainly depends on the depth of the annular groove. The axial compression ratio has a significant effect on the ultimate bearing capacity. Finally, the seismic design method is proposed according to the influence of the above research parameters on the seismic performance of bridge piers, and the method is validated by an example. It is suggested that the range of lateral strength contribution ratio of rubber cushion is 0.028 ~ 0.053.

• Journal of Energy Engineering
• /
• v.19 no.4
• /
• pp.203-214
• /
• 2010

This study is to assess the reduction of greenhouse gas emission and economic contribution by operating nuclear power plants in Korea. According to the results of applying greenhouse gas emission coefficients to the current nuclear power generation and the estimated nuclear power generation of national energy master plan, it is confirmed quantitatively that nuclear power contributes to reducing greenhouse gas emission, controlling inflation, and substituting import of fossil energies. For the reliable and cost-effective supply of energy and the active respondency to climate change, a continuous expansion of nuclear power is implied to be necessary.

• 한국신재생에너지학회:학술대회논문집
• /
• 2007.11a
• /
• pp.658-661
• /
• 2007

It was investigated on this paper that the status of biomass energy utilization in the registered CDM projects. The ratio of the case including the energy recovery among the registered biomass CDM projects is just about 57%. Direct thermal conversion technology is the most commonly applied for biomass energy recovery projects. Through the comparative study with world renewable energy outlook, the contribution of CDM to biomass energy supply in the world is not considerable yet.

• Environmental and Resource Economics Review
• /
• v.20 no.2
• /
• pp.291-308
• /
• 2011

The success of a target of 'low-carbon green growth' depends on whether installing energy-saving capital would result in an increase in industry's productivity growth. Defining total factor productivity from a dual cost function, this paper estimates the contribution of energy efficiency investment to productivity growth by analyzing the sources of growth of productivity index for the primary metal industries. Empirical results show that, on average, energy efficiency investment increased the annual rate of productivity growth by 1.16 percentage points over th period 1982~2006. In addition, The scale effect positively affected the contribution of energy efficiency investment on productivity growth.