• Journal of Korean Society of Coastal and Ocean Engineers
• /
• v.35 no.3
• /
• pp.57-66
• /
• 2023

In order to understand the economic feasibility of an offshore wind farm, this paper analyzed the differences in LCOE (levelized cost of energy) according to the support type and construction method of the substructure in terms of LCOE and sensitivity analysis was conducted according to the main components of LCOE. As for the site to be studied, the Southwest Offshore Wind Farm was selected, and the capital expenditures were calculated according to the size of the offshore wind farm and the installation unit. As a result of the sensitivity analysis, major components showed high sensitivity to availability, turbine related cost, weighted average cost of capital and balance of system related cost. Moreover, the post-piling jacket method, which was representatively applied to the substructure of the offshore wind farm in Korea, was selected as a basic plan to calculate the capital expenditures, and then the capital expenditures of the pre-piling jacket method and the tripod method were calculated and compared. As a result of analyzing the LCOE, it was confirmed that the pre-piling jacket method of the supporting structure lowers the LCOE and improves economic feasibility as the installation number of turbines increases.

• The Journal of the Korea Contents Association
• /
• v.20 no.3
• /
• pp.298-308
• /
• 2020

This study was designed to verify reliability and feasibility by analyzing elderly drivers' ability test tools for older drivers aged 65 or older, which were improved in 2018 and are currently being conducted by the Korea Highway Traffic Authority. Only those aged 65 or older who voluntarily applied to the elderly driving ability evaluation system implemented by the Seoul branch of the Korea Highway Traffic Authority. The research was conducted for about 50 days until Aug. 31, 2018, starting with the registration and inspection of the first study subjects. The analysis performed a correlation analysis with existing tools and cognitive testing tools (MMSE_K) to determine their feasibility and reliability as an improved tool in 2018. As a result, the first, the speed distance, time-space memory, and dispersionism of each sub-component of the old version showed statistically significant static correlation with the sub-factor of the current version. Persistence, on the other hand, was not statistically significant to the current version. The limitations of this study were as follows. Most of the people in the study were highly educated and residents in the metropolitan area. Therefore, it is likely that the results of MSE_K, which checks cognitive and judgment skills, have been upgraded. Also, cognitive tools that are measured by computers are likely to have real measurement errors for generations who are not familiar with computers. Therefore, it is expected that improvement and development of tools for improving the limit points at the site and assessing actual operation capability will be required.

• Korean Journal of Remote Sensing
• /
• v.37 no.5_1
• /
• pp.847-859
• /
• 2021

Recently, as the number of high-resolution satellite SAR images increases, the demand for precise matching of SAR imagesin change detection and image fusion is consistently increasing. RMSE (Root Mean Square Error) values using GCPs (Ground Control Points) selected by analysts have been widely used for quantitative evaluation of image registration results, while it is difficult to find an approach for automatically measuring the registration accuracy. In this study, a feasibility analysis was conducted on using the FSIM (Feature Similarity) index as a measure to evaluate the registration accuracy. TerraSAR-X (TSX) staring spotlight data collected from various incidence angles and orbit directions were used for the analysis. FSIM was almost independent on the spatial resolution of the SAR image. Using a single SAR image, the FSIM with respect to registration errors was analyzed, then use it to compare with the value estimated from TSX data with different imaging geometry. FSIM index slightly decreased due to the differencesin imaging geometry such as different look angles, different orbit tracks. As the result of analyzing the FSIM value by land cover type, the change in the FSIM index according to the co-registration error was most evident in the urban area. Therefore, the FSIM index calculated in the urban was mostsuitable for determining the accuracy of image registration. It islikely that the FSIM index has sufficient potential to be used as an index for the co-registration accuracy of SAR image.

• Journal of the Korea Institute of Building Construction
• /
• v.14 no.2
• /
• pp.127-134
• /
• 2014

This study had the goal of analyzing the economic feasibility and constructability of a fire resistant curtain wall system using Light-weight Inorganic Composite Foam Board(LI-CFB). LI-CFBs, new materials with excellent fire resistance are being developed for use as the back panel of curtain wall and their fire resistance has already been analyzed through actual tests in earlier studies. In this study, a mock-up test involving the installation of the fire resistant curtain wall system on an actual building was conducted, and the system was compared with a common curtain wall system. This system is applied in the same way as a common curtain wall system. But the cutting LI-CFBs, which are brought from a factory, are used in the system and attached on the frame (mullion and transom). Even though the system requires more working time than the existing system, the LI-CFBs back panels are easy to cut and do not produce dust. Also, the panels are able to be assured the quality by checking damaged parts easily. Besides having a high level of fire resistance, the system's economic feasibility and constructability meets or exceeds those of the existing system.

• Journal of Energy Engineering
• /
• v.19 no.2
• /
• pp.103-115
• /
• 2010

Currently, many nations in the world make a strong effort to exploit the new and renewable energy. Tidal energy is the constant and regular power sources with higher and more stable quality compared to other renewable sources. The present paper reports the status of tidal energy analyzing its latest technology and development. In addition, a feasibility study on two types of tidal power plant(TPP) systems is conducted based on many assumptions, conditions and data involved in the Korea environment. The Sihwa and Uldolmok TPP are considered as the reference of tidal barrage(TB) and tidal in stream energy conversion(TISEC) type, respectively. While TB technology is currently mature and reliable, there still remain many environmental issues. Whereas, TISEC is recently received more attention due to its environmental friendly aspect. Therefore, the TISEC is believed to be very promising technology as the TPP. The unit electricity generation cost of Sihwa TPP is approximately 67.3 KRW/kWh. However, considering additional cost of Sihwa lake construction, it increases to 254 KRW/kWh. In Uldolmok, the unit electricity generation cost is calculated to be about 400 KRW/kWh, which is even higher than that of Sihwa TPP. This is ascribed to high cost of TISEC device and construction cost due to its technological infancy as well as relatively small power capacity. Nevertheless, the TISEC technology would be substantially developed in the future due to its many advantageous features.

• Korean Journal of Construction Engineering and Management
• /
• v.11 no.2
• /
• pp.3-14
• /
• 2010

A high degree of management skills and functions is essential to the success of construction projects. While the various construction management delivery methods have been realized as the solutions, Korean government is planning to introduce 'CM at Risk Method' to the public construction projects. However, even if its effect has been verified successful in the international market, it must be considered before legally adapting the method that it would be suitable to our public sector, In this respect, the purpose of this study is to evaluate and analyze feasibility of 'CM at Risk Method'. In order to do that, 15 attributes of construction projects were found, which were suitable to 'CM at Risk Method' in general, 'CM at Risk-GMP Method', and 'CM at Risk-Cost Reimbursable Method' and suitability of each attribute to each of 9 categories of public construction facilities was evaluated by questionnaire survey to CM specialists. Results showed that 'CM at Risk Method' might not bring improper effect to the industry but due to the characteristic of public sector, the effect would be very limited.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.23 no.3
• /
• pp.85-92
• /
• 2015

For concerning the climate change issues, the carbon sequestration and importance of soil organic matter are receiving high attention. To evaluate carbon sequestration in soil is important to determine the soil organic carbon (SOC) fractions such as WESOC (Water extractable soil organic carbon), and $CO_2$ emission by soil microbial respiration. However, the analyses for those contents are time-consuming procedure. There were studied the feasibility of MIRS (Mid-Infrared Spectroscopy), which has short analysis time for determining the WESOC and an incubated carbon in this study. Oven-dried soils at $100^{\circ}C$ and $350^{\circ}C$ were scanned with MIRS and compared with the chemically analyzed WESOC and cumulative carbon dioxide generated during 30, 60, 90, and 120 days of incubation periods, respectively. It was observed that an optimized determination coefficient was 0.6937 between WESOC and untreated soil processed by spectrum vector normalization (SNV) and 0.8933 between cumulative $CO_2$ from 30 days incubation and soil dried at $350^{\circ}C$ after subtracting air-dried soil processed by 1st derivatives. Therefore, it was shown that Quantification of soil organic carbon fractions was possibility to be analyzed by using MIRS.

• Molecular & Cellular Toxicology
• /
• v.3 no.3
• /
• pp.177-184
• /
• 2007

As a possible feasibility of the extrapolation between in vivo and in vitro systems, we investigated the global gene expression from both mouse liver and mouse hepatic cell line treated with hepatotoxic chemical, acetaminophen (APAP), and compared between in vivo and in vitro genomic profiles. For in vivo study, mice were orally treated with APAP and sacrificed at 6 and 24 h. For in vitro study, APAP were administered to a mouse hepatic cell line, BNL CL.2 and sampling was carried out at 6 and 24 h. Hepatotoxicity was assessed by analyzing hepatic enzymes and histopathological examination (in vivo) or lactate dehydrogenase (LDH) assay and morphological examination (in vitro). Global gene expression was assessed using microarray. In high dose APAPtreated group, there was centrilobular necrosis (in vivo) and cellular toxicity with the elevation of LDH (in vitro) at 24 h. Statistical analysis of global gene expression identified that there were similar numbers of altered genes found between in vivo and in vitro at each time points. Pathway analysis identified glutathione metabolism pathway as common pathways for hepatotoxicty caused by APAP. Our results suggest it may be feasible to develop toxicogenomics biomarkers or profiles by comparing in vivo and in vitro genomic profiles specific to this hepatotoxic chemical for application to prediction of liver toxicity.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.1
• /
• pp.1-15
• /
• 2011

The RLC systems is one of the intelligent transportation systems that has gained a nation-wide support for last decades and being installed to discourage motorists from running the red lights at signalized intersections. It is taken for granted that the RLC will provide motorists with increased safety, so that their installments are always justifiable. However, in order to acquire more efficiency and wider supports from the general public in future RLC installments, an improved methodology for analyzing the effects of the RLC systems is required. In order to satisfy this requirement, this research performed the following tasks. First, the number of signal violations after the RLC systems were investigated in order to check its resulting effects. Second, the number of crashes after the RLC systems were collected and compared with the number of signal violations. Third, a statistical analysis was carried out to develop the relationships between the signal violations and the crashes based on negative binomial distribution. The analysis revealed that the number of crashes has a close relationship with the RLC placement, traffic volume, vehicle speed, the number of phases, and the number of lanes for major approaches. Finally, based on the results found in this analysis, this research presents a methodology for analyzing the safety effects of placing the RLC that should be of service when investigating the economic consequences of the RLC systems.

• Journal of the Korean Society of Radiology
• /
• v.13 no.5
• /
• pp.675-681
• /
• 2019

The purpose of this study was to investigate the effect of increasing the amount of 3D volume imaging on the hand, knee, and foot human phantom in CT, After analyzing the data, three - dimensional volumetric images were implemented using MMWP program to evaluate reproducibility. First, the data amount of three human phantoms according to each increment was analyzed. Secondly, the reproducibility evaluation and the measured length were compared. As a result of analyzing the amount of image data for each phantom according to the increment, it was confirmed that the amount of data is reduced to about 1/10 when the increment is set to 1.0 mm as compared with the case where the increment is set to 0.1 mm. In the evaluation of the feasibility, gap was generated from 0.7mm for hand phantom, 0.6mm for knee phantom and foot phantom, and it was confirmed that even when the actual phantom and actual length were compared, the length was much different and the implementation was lowered. As the increment is closer to 1.0mm, the number of images is small and the 3D implementation time is small. Therefore, it is best to determine the increase before the gap of the image is generated and to apply the Increment for preoperative diagnosis. We hope that this study will be an indicator of the accurate increment setting when implementing 3D image through VRT Rendering after CT scan.