• Computers and Concrete
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• v.19 no.5
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• pp.489-499
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• 2017

Self-Compacting Concrete (SCC) is a new technology capable to flow without segregation or any addition of energy which leads to efficient construction and cost savings. In this study, the effect of replacing the Ordinary Portland Cement (OPC) with Fly Ash (FA) on the strength, durability of the concrete was investigated experimentally, and carbon footprint and cost were also assessed. Four different replacement FA ratios (0%, 20%, 40% and 60%) were used to create four SCC mixes. Standard test methods were used to determine the workability, strength, and durability of the SCC mixes including resist chloride ion penetration, water permeability, water absorption, and initial surface absorption. The axial cube compressive strength tests were performed on the SCC mixes at 1, 7, 14, 28 and 35 days. Replacing the OPC with FA had a significant positive impact on chloride iron penetration resistance and water absorption but had a considerable negative impact on the compressive strength. The SCC mix with 60% FA had 36.7% and 15.8% enhancement in the resistance to chloride ion penetration and water absorption, respectively. Evaluation of the carbon footprint and the cost of each SCC mixes showed the $CO_2$ emissions mixes 1, 2, 3 and 4 were significantly reduced by increasing the FA content from 0% to 60%. Compared with the control mix, the cost of all mixes increased when the FA content increased, but no significant differences were seen between the estimated costs of all four mixes.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.409-423
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• 2023

In this study, we analyzed how the revenue water ratio(RWR) is affected by changes in conditions of the water supply area, such as the ratio of aging pipes, maintenance conditions, and revenue water. As a result of analyzing the impact of pipe aging and maintenance conditions on the RWR, it was confirmed that the RWR could be decreased if the pipe replacement project to improve the aging pipe ratio was not carried out and proper maintenance costs were not secured. It was also confirmed that an increase in the revenue water could be operated to facilitate the achievement of the project's target RWR. In contrast, a decrease in the revenue water due to a population reduction could affect the failure of the target RWR. In addition to analyzing the causes of variation in the RWR, the calculation of estimated project costs was considered by using leakage reduction instead of RWR from recent RWR improvement project cost data. From this analysis, it was reviewed whether the project costs planned to achieve the target RWR of the RWR improvement project in A city were appropriate. In conclusion, the RWR could be affected by variations in the ratio of aging pipes, maintenance conditions, and revenue water, and it was reasonable to consider not only the construction input but also the input related to RWR improvement, such as leakage reduction, when calculating the project cost.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.696-700
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• 2007

In case of dome-typed gymnastics training floor, since its form takes shape of the focus of sound, in the occasion when the finishing-material was used with the sandwich panel that prominent in reflexibility, and because the reverberation of sound in indoor is too loud, a smooth practice and teaching is very difficult. As this indoor gymnastics training floor, standing at its character, is required simultaneously the idea communication between the player and the coach, and the acoustic capability regarding to the clearness of music, besides the sport activity, the method to minimize the acoustic defect should be urgently contrived from the stages of design and beginning of construction. On this viewpoint, after investigation on the confidence of the surveyed value and the estimated value using acoustic simulation, and use of the changed finish-material, this thesis intends to design the dome-typed gymnastics training floor that secured the optimized acoustic condition. It is also considered that such result of the study could be utilized as the useful data that enables to improve the retrenchment effect of the construction cost as well as the acoustic performance, by means of the prediction control on the acoustic problem from the stage of design, for the occasion when the similar indoor sport gymnasium is planning to build for the near future.

• Environmental Engineering Research
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• v.20 no.4
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• pp.356-362
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• 2015

Many burial sites were constructed in a short time to prevent the rapid spread of foot and mouth disease in infected livestock carcasses in Korea. More than 4,700 carcass burial sites were constructed in 2011. Approximately seven million poultry and 3.5 million livestock, including cattle and swine, were buried on farmland. Some burial sites were suspected of leachate leakage and were excavated and carcasses redisposed in a bioaugmentation process. This study performed interviews in order to understand the economic issues related to carcass burial and redisposal. The internal data from local government and the assumption data from online sites were analyzed to evaluate the costs; the focus was on burial site construction. The results showed that the local government paid $4.7 and $10.9 per carcass for traditional burial and redisposal. The comparable costs shown online were $4.5. This study found that the standard operating procedures should be carried out to reduce environmental impact and avoid additional costs. We estimated that the cost could be reduced by the advance preparations of materials against the emergency situations such as catastrophe of epidemics. In addition, the innovative technology for the stabilization of carcasses should be established through a future study.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.948-955
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• 2005

In this case of study, Incheon International Airport 2nd phase site preparation 1st section estimated final settlement to improve soft ground. Final settlement is very important in preloading method. Recently, Hyperbolic method, Hoshino method and Asaoka method are used mostly in prediction of final settlement and this paper, Comparing a result of Final settlement, used to Artificial Neural Network. The structure of Dynamic Artificial Neural Network which predicted Final settlement, has application to Young_Jong Island other site, If new investigation data will be added. Also, It is expected to save measuring_system cost in soft ground.

• International Journal of Highway Engineering
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• v.16 no.6
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• pp.181-189
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• 2014

PURPOSES : Ambiguous decision on whether rural or urban area for road design can increase the construction cost and restrict the land use of surrounding area. However, administrative classification on rural and urban area is not directly related to road design because of this classification is not based on the engineering viewpoint, so method which can explain the road design context is required. METHODS : Method which enables to identify the area for road design is suggested based on the deceleration expected to be experienced by drivers who use the road section concerned. Deceleration rate corresponding to the area such as rural or urban suggested in Road Design Guideline is used as the criteria to identify the area by comparing this value with the estimated deceleration rate at the road section concerned. Speed profile method is utilized to derive the deceleration rate, and speed estimation way for reflecting both road geometry and intersection is suggested using stopping sight distance concept. RESULTS : The procedure of the method application is suggested, and the design example utilizing the method is provided. CONCLUSIONS : The method is expected to be used to identify the area for road design with engineering viewpoint, and design consistency among the roads with similar driving environment can be made.

• Explosives and Blasting
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• v.25 no.2
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• pp.35-46
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• 2007

The excavation of ground by blasting is widely accepted during construction of the various infrastructures because the cost is relatively low and its process is simple. Although the ground vibration accompanied by the blasting has drawn many theoretical and experimental research interests, the environmental influence of the air blast tends to be overlooked. This means the noise produced from construction sites have been neglected academically even though it is very controversial and hypersensitive case causing many conflicts in environmental problems. In the light of this, this study explores a way of calculation of air blast. Specifically, we measure the actual air blast and explosive noise, and then make the predicted formula of them based on the change of charge per delay using regression analysis. The comparison with the predicted and measured results helps to determine the validity of estimated formula.

• Journal of Korea Port Economic Association
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• v.17 no.1
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• pp.129-157
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• 2001

In Korea, the quantity of waste is excessive as a result of increases in population and consumption following industrialization. This has resulted in urban environmental problems, a shortage of landfills and pollution around landfills. Thus, there is a need to conduct research in order to find an effective long-term alternative. In Japan, there are more landfills at sea than there are on land. Based on projections for Korea, on-land landfills in the metropolitan area will be filled to capacity by 2020 and then be closed. This research recommends the construction of landfill sites at sea as an alternative waste disposal method. Its findings show that the most the suitable sites for landfills within the Seoul metropolitan area are the regions around Jangbongdo Island and Mueido Island. It also suggests that the best way to transport waste is through the Kyungin Canal from the middle collection center to the lower Han River. The estimated cost of constructing an at-sea landfill to be used for 50 years is approximately two trillion won, with a total construction time of 10 years. In the future, further research related to this study will be conducted in order to ensure that environmentally-friendly landfills are built.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.5
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• pp.881-889
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• 2016

The VE evaluation process, in which the value is composed of the cost and the function, should have a characteristic of quantitative analysis based on specific figures rather than qualitative approach. However, most of the VE evaluation performed domestically have a problem of having no systematic process of quantification of the function, even though the cost is estimated and analyzed quantitatively. Moreover, in addition to the tendency of strong practical experience, the VE evaluation has the problem of limited application of practical scientific analysis caused by declining the suggestion of creative opinions by over quantification or over objectification. This paper presents the suggestions for improvement of VE evaluation processes, which satisfies the aspects of simplification and objectification, without hindering the essence of the evaluation in the practical business point of view.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.518-521
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• 2008

When constructing a high-speed railroad, the reduction of the distance between track centers and the width of track bed will save the construction cost. However the shortening the distance between track centers may cause the stability problems due to higher wind pressure. Therefore the extensive technical review and aerodynamical study should be performed to determine the adequate distance between track centers. In this study, the impact that the increase in wind pressure due to the change of aerodynamic phenomena with the change of the distance between track centers may have on two trains passing by each other was predicted, and the stability of train operation was analyzed in order to review the distance between track centers suitable to Honam HSR trains. And we estimated the aerodynamical effects by the results of the real train experiments by using KTX.