• 환경영향평가
• /
• 제14권6호
• /
• pp.443-453
• /
• 2005

For the purpose of the comparative environmental estimation of the incineration processes for domestic wastes, environmental impacts for several incineration processes for one ton of domestic wastes have been estimated by employing life cycle assessment as the environmental impact assessment method. The scheme of minimum production of environmental pollutants has been considered for three different incineration processes. The evaluation for latent influence on environment was carried out by using CML(Center of Environmental Science) method which was developed by University of Leyden in Netherlands based on the equivalency factor suggested by Korea Accreditation Board. The result of life cycle assessment has showed that the total cost analysis according to the amount of incinerating waste was dependent on the operating conditions of incineration process. In addition, the annual running cost for the incineration of one ton of wastes was estimated to be negatively dependent on the amount of wastes. The degree of environmental pollution was mainly due to the kinds of the wastes rather than by the amount of wastes.

• 자원리싸이클링
• /
• 제23권3호
• /
• pp.3-12
• /
• 2014

본 연구에서는 대표적인 폐기물 최종 처리시설인 소각장을 대상으로 소각열 회수에 따른 경제성 분석을 수행하였다. 국내에서 운영 중인 소각장의 건설 및 운영비용, 소각열 회수량에 대한 함수식을 회귀분석을 통해 도출하였으며, 이를 바탕으로 생애주기비용을 비교함으로써 소각열 회수에 대한 경제성을 비교 분석하였다. 도출된 회귀식으로 일일 80톤 처리규모의 소각장을 기준으로 경제성 분석을 진행한 결과, 소각열 회수시 추가 설비 및 인건비로 인한 초기투자 비용 및 운영비용이 크지만, 열회수에 따른 LNG 대체효과로 계산시 11년 이상 운영할 경우 미회수 소각장과 비교하여 경제적 우위성이 있었다. 또한 열 판매와 온실가스 감축효과를 편익으로 계산할 경우 19년의 자본회수기간이 소요됨을 확인하였다.

• 국제학술발표논문집
• /
• The 9th International Conference on Construction Engineering and Project Management
• /
• pp.170-178
• /
• 2022

A high-performing Earned Value Management System (EVMS) can influence project success and help stakeholders meet project objectives. Although EVMS processes are well-supported by technical guidelines and standards, project managers often face challenges related to the project culture, team, resources, and business practices that make up the project environment within which an EVMS is being used. A comprehensive literature review revealed a lack of a data-driven and consistent assessment frameworks that can gauge the environment surrounding EVMS implementation. This paper will discuss the EVMS environment of construction and environmental projects, and examine its impact on cost performance. The authors used a multi-method approach to identify 27 environment factors that make up the EVMS environment, assessing them on 18 construction and environmental projects worth over $2 billion of total cost. Research methods employed include: (1) a literature review of more than 300 references; (2) a survey of 294 respondents; and (3) remote research charrettes with more than 60 participating expert practitioners. Culture (one of the identified environment categories) was found to be relatively more important in terms of its impact on the EVMS environment, followed by people, practices, and resources. These exploratory results show statistically significant differences in cost performance between completed projects with either a good or poor environment, for the sample projects. Key environment factors are outlined, and guidance is provided to practitioners around how to set up an effective EVMS environment in a construction or environmental project to inform decision-making and support achieving the project cost objectives successfully.

• 환경위생공학
• /
• 제14권2호
• /
• pp.40-45
• /
• 1999

This study deals with an investigation on low cost adsorbents locally available n dyeing wastewater treatment of color removal. Peat, bentonite, slag and fly ash were utilized for this study. Considering that low cost adsorbents contained in $SiO_2$, $Fe_2O_3$ and $Al_2O_3$ compositions, and coagulants were mainly used aluminate and ferrate in color removal. Color of dyeing wastewater was high removed in peat, berntonite and slag except for fly ash with passed time. It could be known that color removal of peat and slag were increased to pH 4, but was hardly changed with advancing to alkaline. Color intended to be high removed with increasing of agitation speed but to be almost slow after 150rpm. As a result on the experiment of Freundlich adsorption isotherms, adsorption intensity(l/n) appeared to be peat>fly ash>slag>bentonite and adsorption capacity(k) came out peat>bentonite>slag>fly ash. Therefore, if low cost adsorbents substituted for existing adsorbents, peat, bentonite and slag could look forward to an expected economical effect.

• 국제학술발표논문집
• /
• The 1th International Conference on Construction Engineering and Project Management
• /
• pp.808-813
• /
• 2005

Effective cost management requires reliable cost estimates at every stage of project development. The primary purpose of this research is to develop systematic modeling procedures and an automatic computing program for infrastructure estimating in the Texas Department of Transportation (TxDOT). The computing system toggles between project input information and segregated district unit prices for highway work item quantity estimates associated with earthwork and landscape, subgrade treatments and base, surface courses and pavement, structures, miscellaneous construction, and lighting, signing, markings and signals. This quantity-based approach was chosen because of the conventional approach lacking of quantity information until primary design is complete.

• 대한안전경영과학회지
• /
• 제15권4호
• /
• pp.253-260
• /
• 2013

The importance of environmental protection has been increased recently. Thus the environmental management was settled in an important global competition factor. In the meantime logistics cost occupied the 8.03% of sales at 2011. This portion was greater than the portion of other countries and it was needed the reduction of logistics cost to secure the competition power. As thus in this paper we prepared the process which diminish the environmental discharge and decrease the logistics cost. We proposed the process to apply the MFCA to SCM, until now the MFCA had been used generally in manufacturing process. We defined the loss in SCM and the plus logistic, minus logistic, logistic center and the classification of cost to adopt the MFCA to SCM.

• Geomechanics and Engineering
• /
• 제7권5호
• /
• pp.525-537
• /
• 2014

The typical design of ground improvement with prefabricated vertical drains (PVD) and surcharge preloading involves a series of deterministic analyses using averaged or mean soil properties for the various combination of the PVD spacing and surcharge preloading height that would meet the criteria for minimum consolidation time and required degree of consolidation. The optimum design combination is then selected in which the total cost of ground improvement is a minimum. Considering the variability and uncertainties of the soil consolidation parameters, as well as considering the effects of soil disturbance (smear zone) and drain resistance in the analysis, this study presents a stochastic cost optimization of ground improvement with PVD and surcharge preloading. Direct Monte Carlo (MC) simulation and importance sampling (IS) technique is used in the stochastic analysis by limiting the sampled random soil parameters within the range from a minimum to maximum value while considering their statistical distribution. The method has been verified in a case study of PVD improved ground with preloading, in which average results of the stochastic analysis showed a good agreement with field monitoring data.

• Korean Journal of Hydrosciences
• /
• 제8권
• /
• pp.31-40
• /
• 1997

Flow carrying capacity of water distribution systems is getting reduced by deterioration of pipes in the systems. The objective of this paper is to present a managerial decision-making model for the rehabilitation of water distribution systems with a mininum cost. The decisions made by the model also satisfy the requirements for discharge and pressure at demanding nodes in the systems. Replacement cost, pipe break repair cost, and pumping cost are considered in the economic evaluation of the decision along with the break rate and the interest rate to determine the optimal replacement time for each pipe. Then, the hydraulic integrity of the water distribution system is checked for the decision by a pipe network simulator, KYPIPE, if discharge and pressure requirements are satisfied. In case the system does not satisfy the hydraulic requirements, the decision made for the optimal replacement time is revised until the requirments are satisfied. The model is well applied to an existing water distribution system, the Seoul Metropolitan Water Supply System (1st Phase). The results show that the decisions for the replacement time determined by the economic analysis are accepted as optimal and hydraulic integrity of the system is in good condition.

• Computers and Concrete
• /
• 제25권2호
• /
• pp.167-179
• /
• 2020

Optimal design of structures against earthquake loads is often limited to reduce initial construction costs, while the cost induced to structures during their useful life may be several times greater than the initial costs. Therefore, it is necessary to consider the indirect costs due to earthquakes in the design process. In this research, an integrated methodology for calculating life cycle cost (LCC) of moment-resisting concrete frames is presented. Increasing seismic safety of structures and reducing human casualties can play an important role in determining the optimal design. Costs incurred for structures are added to the costs of construction, including the costs of reconstruction, financial losses due to the time spent on reconstruction, interruption in building functionality, the value of people's life or disability, and content loss are a major part of the future costs. In this research, fifty years of useful life of structures from the beginning of the construction is considered as the life cycle. These costs should be considered as factors of calculating indirect costs of a structure. The results of this work represent the life cycle cost of a 4 story, 7 story, and 10 story moment-resisting concrete frame by details. This methodology is developed based on the economic conditions of Iran in 2016 and for the case of Tehran city.

• Smart Structures and Systems
• /
• 제6권5_6호
• /
• pp.689-709
• /
• 2010

In this paper, a low cost, low power but multifunctional wireless sensor node is presented for the impedance-based SHM using piezoelectric sensors. Firstly, a miniaturized impedance measuring chip device is utilized for low cost and low power structural excitation/sensing. Then, structural damage detection/sensor self-diagnosis algorithms are embedded on the on-board microcontroller. This sensor node uses the power harvested from the solar energy to measure and analyze the impedance data. Simultaneously it monitors temperature on the structure near the piezoelectric sensor and battery power consumption. The wireless sensor node is based on the TinyOS platform for operation, and users can take MATLAB$^{(R)}$ interface for the control of the sensor node through serial communication. In order to validate the performance of this multifunctional wireless impedance sensor node, a series of experimental studies have been carried out for detecting loose bolts and crack damages on lab-scale steel structural members as well as on real steel bridge and building structures. It has been found that the proposed sensor nodes can be effectively used for local wireless health monitoring of structural components and for constructing a low-cost and multifunctional SHM system as "place and forget" wireless sensors.