Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to ...Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to perform real-time evaluations to explore various design options. However, when integrated with LCCA, BIM provides a comprehensive economic perspective that helps stakeholders understand the long-term financial implications of design decisions. This study presents a methodology for developing a model that seamlessly integrates BIM and LCCA during the conceptual design stage of buildings. This integration allows for a comprehensive evaluation and analysis of the design process, ensuring that the development aligns with the principles of low carbon emissions by employing modular construction, 3D concrete printing methods, and different building design alternatives. The model considers the initial construction costs in addition to all the long-term operational, maintenance, and salvage values. It combines various tools and data through different modules, including energy analysis, Life Cycle Assessment (LCA), and Life Cycle Cost Analysis (LCCA) to execute a comprehensive assessment of the financial implications of a specific design option throughout the lifecycle of building projects. The development of the said model and its implementation involves the creation of a new plug-in for the BIM tool (i.e., Autodesk Revit) to enhance its functionalities and capabilities in forecasting the life-cycle costs of buildings in addition to generating associated cash flows, creating scenarios, and sensitivity analyses in an automatic manner. This model empowers designers to evaluate and justify their initial investments while designing and selecting potential construction methods for buildings, and enabling stakeholders to make informed decisions by assessing different design alternatives based on long-term financial considerations during the early stages of design.展开更多
In recent years, there has been global interest in meeting targets relating to energy affordability and security while taking into account greenhouse gas emissions. This has heightened major interest in potential inve...In recent years, there has been global interest in meeting targets relating to energy affordability and security while taking into account greenhouse gas emissions. This has heightened major interest in potential investigations into the use of supercritical carbon dioxide (sCO2) power cycles. Climate change mitigation is the ultimate driver for this increased interest;other relevant issues include the potential for high cycle efficiency and a circular economy. In this study, a 25 MWe recompression closed Brayton cycle (RCBC) has been assessed, and sCO2 has been proposed as the working fluid for the power plant. The methodology used in this research work comprises thermodynamic and techno-economic analysis for the prospective commercialization of this sCO2 power cycle. An evaluated estimation of capital expenditure, operational expenditure, and cost of electricity has been considered in this study. The ASPEN Plus simulation results have been compared with theoretical and mathematical calculations to assess the performance of the compressors, turbine, and heat exchangers. The results thus reveal that the cycle efficiency for this prospective sCO2 recompression closed Brayton cycle increases (39% - 53.6%) as the temperature progressively increases from 550˚C to 900˚C. Data from the Aspen simulation model was used to aid the cost function calculations to estimate the total capital investment cost of the plant. Also, the techno-economic results have shown less cost for purchasing equipment due to fewer components being required for the cycle configuration as compared to the conventional steam power plant.展开更多
Based on the consideration of operation environment and structural property, an optimum design model of offshore jacket platform is developed in this paper, namely, the reliability-based full-life cycle optimum design...Based on the consideration of operation environment and structural property, an optimum design model of offshore jacket platform is developed in this paper, namely, the reliability-based full-life cycle optimum design model. In this model, the time-dependent reliability assessment method for structural members is established by combination of the decrease of sectional size and performance deterioration of material. The initial investment, maintenance cost and failure loss cost are assembled into the model. The total cost of the platform structure system in its full service period is chosen as the objective function, and the initial reliabilities of the layer elements partitioned in advance are taken as the design variables. Different models are obtained, depending on whether the system reliability constraint is considered or not. This optimum design model can result in the lowest full-life cost and the optimal initial layer reliability of an offshore jacket platform in the design of marine structures. The feasibility of this model is illustrated with an actual jacket platform in the Liaodong Gulf as an example.展开更多
Pavement performance and economic efficiency are researched on the perpetual test pavement of Yijiang-Suzhou Express Highway in Jiangsu province, China. Test sections were continuously monitored. The conditions and de...Pavement performance and economic efficiency are researched on the perpetual test pavement of Yijiang-Suzhou Express Highway in Jiangsu province, China. Test sections were continuously monitored. The conditions and developing laws of deflection, rutting and cracking are compared among the perpetual pavement with the rich binder layer (RBL), the perpetual pavement without the RBL, and the conventional semi-rigid asphalt pavement in the past eight years after opening for traffic. Economical evaluation is conducted via life cycle cost analysis (LCCA). Based on the performance comparison and LCCA analysis, sections with the RBL have good crack resistance, but they are not very satisfactory in the aspect of permanent deformation; the conventional semi-rigid asphalt pavement is the least economic one due to requiring more frequent maintenance. Research results show that the perpetual pavement without RBL is a more appropriate structure for the test site.展开更多
Life Cycle Costing (LCC) is always a major concern in the Architecture, Engineering and Construction (AEC) industry. This paper presents the implementation of Building Information Modeling (BIM) technology in the deve...Life Cycle Costing (LCC) is always a major concern in the Architecture, Engineering and Construction (AEC) industry. This paper presents the implementation of Building Information Modeling (BIM) technology in the development of a lifecycle cost-estimating tool. The IFC (Industry Foundation Classes) model as an interoperable building information model has been adopted as the central data repository to deliver the integrated information of building designs from CAD design systems into the lifecycle-costing database. In this paper, the conceptions and relevant factors, which could affect the LCC estimation, have been introduced. The problems of current LCC applications have been identified as the lack of LCC data and the complexity of LCC exercises. The software application of IFC models and relevant auxiliary are depicted as a solution of the problem identified. The lifecycle costing tool is a part of the nD Modeling tool and as such is based on its integrated interface prototype toolkit and is able to holistically present an IFC model into a 3D virtual reality view, a tree-view and a list of element properties. The functions and some technical points are also detailed in the paper. Through the research, it demonstrates the potential and possibility of implementing BIM methods and techniques, particularly IFCs to enhance the computer applications in the processes of building construction and facility management.展开更多
The problem of sequential fault diagnosis is to construct a diagnosis tree that can isolate the failure sources with minimal test cost. Pervious sequential fault diagnosis strategy generating algorithms only consider ...The problem of sequential fault diagnosis is to construct a diagnosis tree that can isolate the failure sources with minimal test cost. Pervious sequential fault diagnosis strategy generating algorithms only consider the execution cost at application stage, which may result in a solution with poor quality from the view of life cycle cost. Furthermore, due to the fact that uncertain information exists extensively in the real-world systems, the tests are always imperfect. In order to reduce the cost of fault diagnosis in the realistic systems, the sequential fault diagnosis problem with imperfect tests considering life cycle cost is presented and formulated in this work, which is an intractable NP-hard AND/OR decision tree construction problem. An algorithm based on AND/OR graph search is proposed to solve this problem. Heuristic search based on information theory is applied to generate the sub-tree in the algorithm. Some practical issues such as the method to improve the computational efficiency and the diagnosis strategy with multi-outcome tests are discussed. The algorithm is tested and compared with previous algorithms on the simulated systems with different scales and uncertainty. Application on a wheel momentum system of a spacecraft is studied in detail. Both the simulation and application results suggest that the cost of the diagnosis strategy can be reduced significantly by using the proposed algorithm, especially when the placement cost of the tests constitutes a large part of the total cost.展开更多
To making the decision of the developing blue prints,ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo.At the same time,the concept of grey relational entropy of the grey sy...To making the decision of the developing blue prints,ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo.At the same time,the concept of grey relational entropy of the grey system theory was adopted to compute the distance between each blue print and the ideal point(or negative ideal point).The blue print,nearest to the ideal point and farthest to the negative ideal point,is the best one.As an example,four blue prints of torpedo were estimated.The result indicates the practical value of this method.展开更多
Parabolic trough collectors (PTCs) are employed for a variety of applications including steam generation and hot water generation. This paper deals with the experimental results and an economic analysis of a new fib...Parabolic trough collectors (PTCs) are employed for a variety of applications including steam generation and hot water generation. This paper deals with the experimental results and an economic analysis of a new fibre reinforced plastic (FRP) based solar PTC with an embedded electronic controlled tracking system designed and developed for hot water generation in a restaurant in Madurai, India. The new collector performance has been tested according to ASHRAE Standard 93 (1986). The performance of a new PTC hot water generation system with a well mixed hot water storage tank is investigated by a series of extensive tests over ten months period. The average maximum storage tank water temperature observed was 74.91℃, when no energy is withdrawn from the tank to the load during the collection period. The total cost of the new economic FRP based solar PTC for hot water generation with an embedded electronic controlled tracking system is Rs. 25000 (US$ 573) only. In the present work, life cycle savings (LCS) method is employed for a detailed economic analysis of the PTC system. A computer program is used as a tool for the economic analysis. The present worth of life cycle solar savings is evaluated for the new solar PTC hot water generation system that replaces an existing electric water heating system in the restaurant and attains a value of Rs. 23171.66 after 15 years, which is a significant saving. The LCS method and the MATLAB computer simulation program presented in this paper can be used to estimate the LCS of other renewable energy systems.展开更多
India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY (Rejiv Gandhi Grammen Vidyutikaran Yojana), the rate of village electrification is much lower as household connec...India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY (Rejiv Gandhi Grammen Vidyutikaran Yojana), the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers (both dual fuel and pure gas type) and compare with that of diesel generating sets by using the concept of LCC (life cycle costing) and Homer software. It is found that the cost of per unit electricity generation (kWh) has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent.展开更多
Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vit...Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vitamins,and bioactive substances.Additionally,they aid in improving the environment due to their higher extraction rate and lower carbon emission during the processing stage.However,few studies have attempted to evaluate the economic and social benefits of increasing the amount of whole grain in grain intake.This paper estimates the potential savings in healthcare costs and reduced food carbon footprints(CFs)that could result from a shift toward whole grain consumption following the Chinese Dietary Guidelines(CDG).We investigate hypothetical scenarios where a certain proportion(5–100%)of Chinese adults could increase their whole grain intakes as proposed by CDG to meet the average shortfall of 30.2 g.In that case,the healthcare costs for associated diseases(e.g.,type2 diabetes mellitus(T2DM),cardiovascular disease(CVD),and colorectal cancer(CRC))are expected to reduce by a substantial amount,from USD 2.82 to 56.37 billion;the carbon emission levels are also projected to decrease by0.24–5.72 million tons.This study provides compelling evidence that advocating for the transition towards greater consumption of whole grain products could benefit individual health,the environment,and society,by reducing both healthcare costs and carbon emissions.展开更多
Reliability, maintainability, supportability (RMS) are the important performance indexes of equipment, which affect not only the availability, but also the life cycle cost (LCC) of the equipment. First discussed i...Reliability, maintainability, supportability (RMS) are the important performance indexes of equipment, which affect not only the availability, but also the life cycle cost (LCC) of the equipment. First discussed is the qualitative relation between reliability and LCC and the costs which may be used to enhance the reliability. Secondly, the factors that affect the maintainability are summarized, and if maintainability is advanced, the trend of the LCC is depicted. Thirdly, the qualitative relation between the supportability and LCC is described. Reliability, maintainability and supportability index all have a relation with the availability, so this paper presents the tradeoff for RMS indexes based on the availability calculation models and LCC models. On the condition that the availability value is not below the given value, the decision-making is optimal if the life cycle cost is the minimum value.展开更多
The selection of power transformer is very important to power sector. Most methods are utilized according to the initial cost and don’t consider the synthetical evaluation of economy and technology. Based on previous...The selection of power transformer is very important to power sector. Most methods are utilized according to the initial cost and don’t consider the synthetical evaluation of economy and technology. Based on previous research, this paper addresses a new practical probabilistic life cycle cost model. Then, in order to demonstrate the practicability of probabilistic life cycle cost for the power transformer, illustrative investment alternatives of actual power transformers are discussed. From the result of the numerical investigation, it may be positively stated that the optimum investment alternative for the power transformer based on the probabilistic life cycle cost model proposed in this study will lead to a more rational, economical and effective procedure compared with the conventional method only considering the initial cost.展开更多
This research indicates that with the changes in economic cycles, China's production costs are experiencing "wave-shaped" spiral growth. From 2004 to 2008, China's grain production costs increased ra...This research indicates that with the changes in economic cycles, China's production costs are experiencing "wave-shaped" spiral growth. From 2004 to 2008, China's grain production costs increased rapidly, with the primary driving force the rapid growth of labor, land and material costs. In the middle stage of industrialization, China's grain production costs will experience spiral growth following economic cyclical fluctuations, entering relative stability after a certain period. From 2009 to around 2012, grain production costs will drop, but average production costs may be higher than in the current upward cycle. From 2013 to around 2020, grain production costs will rise again and be much higher than in the current upward cycle.展开更多
The construction industry is a sector that contributes a lot to the economic growth of Malaysia, as it is developing rapidly similar in fashion to other developing countries around the world. In line with the 9th Mala...The construction industry is a sector that contributes a lot to the economic growth of Malaysia, as it is developing rapidly similar in fashion to other developing countries around the world. In line with the 9th Malaysia Plan, development in Malaysia must meet current and future needs to achieve sustainability in economic development, as well as functioning as a social and environmental responsibility for prosperity without compromising the needs of future generations. To ensure that the government's objective is met, construction industry should implement the LCC (life cycle costing) method in structure and infrastructure projects so as to not cause losses to the industry itself and to the government. Through LCC, factors contributing to, and the associated cost of maintenance works for a building are identified at the design stage to obtain a more accurate projection of the total cost. This paper describes the LCC as a vital element in the construction industry since this method can drive quality improvement by taking into account the comprehensive cost of a project. The main aim of this paper is to aid in understanding the application of the LCC concept for the construction industry, particularly for the maintenance phase. This paper also identifies LCC processes involved in a building construction project and subsequently provides recommendation on appropriate measures to implement LCC in the construction industry in Malaysia.展开更多
For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribu...For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribution network equipment and capacity from the perspective of life cycle cost.Compared with the traditional energy network,the equipment capacity problem of energy interconnected distribution network which involves in electricity network,thermal energy network and natural gas network is comprehensively considered in this paper.On this basis,firstly,the operation architecture of energy interconnected distribution network is designed.Secondly,taking the grid connection location and configuration capacity of key equipment in the system as the control variables and the operation cost of system comprehensive planning in the whole life cycle as the goal,the equipment location and capacity optimization model of energy interconnected distribution network is established.Finally,an IEEE 33 bus energy mutual distribution grid system is taken for example analysis,and the improved chaotic particle swarmoptimization algorithm is used to solve it.The simulation results show that the method proposed in this paper is suitable for the equipment location and capacity planning of energy interconnected distribution network,and it can effectively improve the social and economic benefits of system operation.展开更多
The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This stu...The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This study explains the concept and method of PV, and then provides an explanation of the concept and method of NPV, and points out the limitations in the practical application of the method.展开更多
With the advent of the fourth industrial revolution,the construction industry has undergone a paradigm shift.The smart construction technology market is expected to grow 12%annually in developed countries due to advan...With the advent of the fourth industrial revolution,the construction industry has undergone a paradigm shift.The smart construction technology market is expected to grow 12%annually in developed countries due to advanced technology investments.It is expected that businesses requiring highly sophisticated technology,for instance companies that need their old facilities upgraded,will become the main focus of the market.As building information modeling(BIM)design is becoming mandatory,such as in the Korea Public Procurement Service,researches regarding building automation,construction,and operation integration management systems based on BIM are conducted.In addition,for construction projects of over 10 billion won,design value engineering(Design VE)implementation,including life cycle cost(LCC)analysis,is mandatory at the design stage to improve quality and reduce the lifetime costs of buildings.In this study,we propose an improvement plan for LCC analysis at the design stage using the KBIMS library,which is an open BIM library developed by the Korean government and research groups.We analyze the existing LCC method,KBIMS library,and attribute information,and model the process that is applied in the LCC analysis system.This is expected to complement the LCC analysis system and improve work productivity.展开更多
After the introduction of BTL (Build-Transfer-Lease) projects in 2005, most construction projects of school facilities have been implemented in BTL system. However, concern about whether the school facilities can be...After the introduction of BTL (Build-Transfer-Lease) projects in 2005, most construction projects of school facilities have been implemented in BTL system. However, concern about whether the school facilities can be managed appropriately during the 20 year as operation and management period is increasing. Therefore, the necessity of reference for evaluation standard on operating costs and the establishment of LCC (life cycle costing) prediction models is coming to the fore. In this respect, the goal of this study was to extract the variables for LCC-related models and conduct analyses of the correlations of the variables using statistical analysis tool, in order to establish LCC prediction and backtracking model based on BTL project cases of school facilities. The prediction and backtracking model of LCC will be a key for budget equalization or optimum range as one way of estimating method using LCC by year and school type. In the future, it would provide the accurate reference for analyzing and managing the actual input costs against the plan and evaluating the practical cost for long-term facility management plan as the predictive management.展开更多
In this article,a total life cycle cost analysis(LCCA)was developed covering two transportation systems:trucking and railway within the Gulf Cooperation Council(GCC)region.GCC region is a regional intergovernmental po...In this article,a total life cycle cost analysis(LCCA)was developed covering two transportation systems:trucking and railway within the Gulf Cooperation Council(GCC)region.GCC region is a regional intergovernmental political and economic union consists of six countries(Saudi Arabia,Kuwait,the United Arab Emirates,Qatar,Bahrain,and Oman).In general and based on statistics,the GCC regional economy is expected to grow due to the increase in aggregate supply and demand.So,there is a need to build a solid foundation of transportation systems that can help in transforming this region into a logistics hub.Therefore,different analysis was discussed in order to be able to select more reliable and appropriate mode of shipping between the GCC.Beside the main cost factors that which includes the capital,operational,maintenance and depreciation costs.Other factors such as,border delays,emissions,noise and safety factors were added to the analysis.The results show that,shipping using trucking system can be cheaper when shipping commodities between the GCC region,but at the same time considering border delays and emission produced,railways and intermodal modal systems prove to be more reliable.Moreover,shipping bulk commodities favor the rail and intermodal systems due to the payload capacity besides the flexibility of finding the most efficient way to move the shipments between origin and destinations.展开更多
文摘Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to perform real-time evaluations to explore various design options. However, when integrated with LCCA, BIM provides a comprehensive economic perspective that helps stakeholders understand the long-term financial implications of design decisions. This study presents a methodology for developing a model that seamlessly integrates BIM and LCCA during the conceptual design stage of buildings. This integration allows for a comprehensive evaluation and analysis of the design process, ensuring that the development aligns with the principles of low carbon emissions by employing modular construction, 3D concrete printing methods, and different building design alternatives. The model considers the initial construction costs in addition to all the long-term operational, maintenance, and salvage values. It combines various tools and data through different modules, including energy analysis, Life Cycle Assessment (LCA), and Life Cycle Cost Analysis (LCCA) to execute a comprehensive assessment of the financial implications of a specific design option throughout the lifecycle of building projects. The development of the said model and its implementation involves the creation of a new plug-in for the BIM tool (i.e., Autodesk Revit) to enhance its functionalities and capabilities in forecasting the life-cycle costs of buildings in addition to generating associated cash flows, creating scenarios, and sensitivity analyses in an automatic manner. This model empowers designers to evaluate and justify their initial investments while designing and selecting potential construction methods for buildings, and enabling stakeholders to make informed decisions by assessing different design alternatives based on long-term financial considerations during the early stages of design.
文摘In recent years, there has been global interest in meeting targets relating to energy affordability and security while taking into account greenhouse gas emissions. This has heightened major interest in potential investigations into the use of supercritical carbon dioxide (sCO2) power cycles. Climate change mitigation is the ultimate driver for this increased interest;other relevant issues include the potential for high cycle efficiency and a circular economy. In this study, a 25 MWe recompression closed Brayton cycle (RCBC) has been assessed, and sCO2 has been proposed as the working fluid for the power plant. The methodology used in this research work comprises thermodynamic and techno-economic analysis for the prospective commercialization of this sCO2 power cycle. An evaluated estimation of capital expenditure, operational expenditure, and cost of electricity has been considered in this study. The ASPEN Plus simulation results have been compared with theoretical and mathematical calculations to assess the performance of the compressors, turbine, and heat exchangers. The results thus reveal that the cycle efficiency for this prospective sCO2 recompression closed Brayton cycle increases (39% - 53.6%) as the temperature progressively increases from 550˚C to 900˚C. Data from the Aspen simulation model was used to aid the cost function calculations to estimate the total capital investment cost of the plant. Also, the techno-economic results have shown less cost for purchasing equipment due to fewer components being required for the cycle configuration as compared to the conventional steam power plant.
文摘Based on the consideration of operation environment and structural property, an optimum design model of offshore jacket platform is developed in this paper, namely, the reliability-based full-life cycle optimum design model. In this model, the time-dependent reliability assessment method for structural members is established by combination of the decrease of sectional size and performance deterioration of material. The initial investment, maintenance cost and failure loss cost are assembled into the model. The total cost of the platform structure system in its full service period is chosen as the objective function, and the initial reliabilities of the layer elements partitioned in advance are taken as the design variables. Different models are obtained, depending on whether the system reliability constraint is considered or not. This optimum design model can result in the lowest full-life cost and the optimal initial layer reliability of an offshore jacket platform in the design of marine structures. The feasibility of this model is illustrated with an actual jacket platform in the Liaodong Gulf as an example.
基金The Science and Technology Project of Jiangsu Provincial Communications Department(No.7621000078)
文摘Pavement performance and economic efficiency are researched on the perpetual test pavement of Yijiang-Suzhou Express Highway in Jiangsu province, China. Test sections were continuously monitored. The conditions and developing laws of deflection, rutting and cracking are compared among the perpetual pavement with the rich binder layer (RBL), the perpetual pavement without the RBL, and the conventional semi-rigid asphalt pavement in the past eight years after opening for traffic. Economical evaluation is conducted via life cycle cost analysis (LCCA). Based on the performance comparison and LCCA analysis, sections with the RBL have good crack resistance, but they are not very satisfactory in the aspect of permanent deformation; the conventional semi-rigid asphalt pavement is the least economic one due to requiring more frequent maintenance. Research results show that the perpetual pavement without RBL is a more appropriate structure for the test site.
文摘Life Cycle Costing (LCC) is always a major concern in the Architecture, Engineering and Construction (AEC) industry. This paper presents the implementation of Building Information Modeling (BIM) technology in the development of a lifecycle cost-estimating tool. The IFC (Industry Foundation Classes) model as an interoperable building information model has been adopted as the central data repository to deliver the integrated information of building designs from CAD design systems into the lifecycle-costing database. In this paper, the conceptions and relevant factors, which could affect the LCC estimation, have been introduced. The problems of current LCC applications have been identified as the lack of LCC data and the complexity of LCC exercises. The software application of IFC models and relevant auxiliary are depicted as a solution of the problem identified. The lifecycle costing tool is a part of the nD Modeling tool and as such is based on its integrated interface prototype toolkit and is able to holistically present an IFC model into a 3D virtual reality view, a tree-view and a list of element properties. The functions and some technical points are also detailed in the paper. Through the research, it demonstrates the potential and possibility of implementing BIM methods and techniques, particularly IFCs to enhance the computer applications in the processes of building construction and facility management.
基金Project(C1320063131)supported by China Civil Space Foundation
文摘The problem of sequential fault diagnosis is to construct a diagnosis tree that can isolate the failure sources with minimal test cost. Pervious sequential fault diagnosis strategy generating algorithms only consider the execution cost at application stage, which may result in a solution with poor quality from the view of life cycle cost. Furthermore, due to the fact that uncertain information exists extensively in the real-world systems, the tests are always imperfect. In order to reduce the cost of fault diagnosis in the realistic systems, the sequential fault diagnosis problem with imperfect tests considering life cycle cost is presented and formulated in this work, which is an intractable NP-hard AND/OR decision tree construction problem. An algorithm based on AND/OR graph search is proposed to solve this problem. Heuristic search based on information theory is applied to generate the sub-tree in the algorithm. Some practical issues such as the method to improve the computational efficiency and the diagnosis strategy with multi-outcome tests are discussed. The algorithm is tested and compared with previous algorithms on the simulated systems with different scales and uncertainty. Application on a wheel momentum system of a spacecraft is studied in detail. Both the simulation and application results suggest that the cost of the diagnosis strategy can be reduced significantly by using the proposed algorithm, especially when the placement cost of the tests constitutes a large part of the total cost.
基金the Doctorate Foundation of Northwestern Polytechnical University (Grant No.CX200304)
文摘To making the decision of the developing blue prints,ideal point method was selected to estimate the life cycle cost with effectiveness of torpedo.At the same time,the concept of grey relational entropy of the grey system theory was adopted to compute the distance between each blue print and the ideal point(or negative ideal point).The blue print,nearest to the ideal point and farthest to the negative ideal point,is the best one.As an example,four blue prints of torpedo were estimated.The result indicates the practical value of this method.
文摘Parabolic trough collectors (PTCs) are employed for a variety of applications including steam generation and hot water generation. This paper deals with the experimental results and an economic analysis of a new fibre reinforced plastic (FRP) based solar PTC with an embedded electronic controlled tracking system designed and developed for hot water generation in a restaurant in Madurai, India. The new collector performance has been tested according to ASHRAE Standard 93 (1986). The performance of a new PTC hot water generation system with a well mixed hot water storage tank is investigated by a series of extensive tests over ten months period. The average maximum storage tank water temperature observed was 74.91℃, when no energy is withdrawn from the tank to the load during the collection period. The total cost of the new economic FRP based solar PTC for hot water generation with an embedded electronic controlled tracking system is Rs. 25000 (US$ 573) only. In the present work, life cycle savings (LCS) method is employed for a detailed economic analysis of the PTC system. A computer program is used as a tool for the economic analysis. The present worth of life cycle solar savings is evaluated for the new solar PTC hot water generation system that replaces an existing electric water heating system in the restaurant and attains a value of Rs. 23171.66 after 15 years, which is a significant saving. The LCS method and the MATLAB computer simulation program presented in this paper can be used to estimate the LCS of other renewable energy systems.
文摘India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY (Rejiv Gandhi Grammen Vidyutikaran Yojana), the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers (both dual fuel and pure gas type) and compare with that of diesel generating sets by using the concept of LCC (life cycle costing) and Homer software. It is found that the cost of per unit electricity generation (kWh) has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent.
基金the National Natural Science Foundation of China(72203214 and 72061147002)China Scholarship Council(CSC)(201913043)。
文摘Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vitamins,and bioactive substances.Additionally,they aid in improving the environment due to their higher extraction rate and lower carbon emission during the processing stage.However,few studies have attempted to evaluate the economic and social benefits of increasing the amount of whole grain in grain intake.This paper estimates the potential savings in healthcare costs and reduced food carbon footprints(CFs)that could result from a shift toward whole grain consumption following the Chinese Dietary Guidelines(CDG).We investigate hypothetical scenarios where a certain proportion(5–100%)of Chinese adults could increase their whole grain intakes as proposed by CDG to meet the average shortfall of 30.2 g.In that case,the healthcare costs for associated diseases(e.g.,type2 diabetes mellitus(T2DM),cardiovascular disease(CVD),and colorectal cancer(CRC))are expected to reduce by a substantial amount,from USD 2.82 to 56.37 billion;the carbon emission levels are also projected to decrease by0.24–5.72 million tons.This study provides compelling evidence that advocating for the transition towards greater consumption of whole grain products could benefit individual health,the environment,and society,by reducing both healthcare costs and carbon emissions.
基金supported by the National Postdoctoral Science Foundation of P. R. China Under Grant No. 20080431380
文摘Reliability, maintainability, supportability (RMS) are the important performance indexes of equipment, which affect not only the availability, but also the life cycle cost (LCC) of the equipment. First discussed is the qualitative relation between reliability and LCC and the costs which may be used to enhance the reliability. Secondly, the factors that affect the maintainability are summarized, and if maintainability is advanced, the trend of the LCC is depicted. Thirdly, the qualitative relation between the supportability and LCC is described. Reliability, maintainability and supportability index all have a relation with the availability, so this paper presents the tradeoff for RMS indexes based on the availability calculation models and LCC models. On the condition that the availability value is not below the given value, the decision-making is optimal if the life cycle cost is the minimum value.
文摘The selection of power transformer is very important to power sector. Most methods are utilized according to the initial cost and don’t consider the synthetical evaluation of economy and technology. Based on previous research, this paper addresses a new practical probabilistic life cycle cost model. Then, in order to demonstrate the practicability of probabilistic life cycle cost for the power transformer, illustrative investment alternatives of actual power transformers are discussed. From the result of the numerical investigation, it may be positively stated that the optimum investment alternative for the power transformer based on the probabilistic life cycle cost model proposed in this study will lead to a more rational, economical and effective procedure compared with the conventional method only considering the initial cost.
文摘This research indicates that with the changes in economic cycles, China's production costs are experiencing "wave-shaped" spiral growth. From 2004 to 2008, China's grain production costs increased rapidly, with the primary driving force the rapid growth of labor, land and material costs. In the middle stage of industrialization, China's grain production costs will experience spiral growth following economic cyclical fluctuations, entering relative stability after a certain period. From 2009 to around 2012, grain production costs will drop, but average production costs may be higher than in the current upward cycle. From 2013 to around 2020, grain production costs will rise again and be much higher than in the current upward cycle.
文摘The construction industry is a sector that contributes a lot to the economic growth of Malaysia, as it is developing rapidly similar in fashion to other developing countries around the world. In line with the 9th Malaysia Plan, development in Malaysia must meet current and future needs to achieve sustainability in economic development, as well as functioning as a social and environmental responsibility for prosperity without compromising the needs of future generations. To ensure that the government's objective is met, construction industry should implement the LCC (life cycle costing) method in structure and infrastructure projects so as to not cause losses to the industry itself and to the government. Through LCC, factors contributing to, and the associated cost of maintenance works for a building are identified at the design stage to obtain a more accurate projection of the total cost. This paper describes the LCC as a vital element in the construction industry since this method can drive quality improvement by taking into account the comprehensive cost of a project. The main aim of this paper is to aid in understanding the application of the LCC concept for the construction industry, particularly for the maintenance phase. This paper also identifies LCC processes involved in a building construction project and subsequently provides recommendation on appropriate measures to implement LCC in the construction industry in Malaysia.
基金The authors received specific funding for State Grid Corporation Headquarters Project Support,Key Technologies and Applications of Planning and Decision-Making Based on the Full Cost Chain of the Power Grid,Grant No.5205331800001.
文摘For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribution network equipment and capacity from the perspective of life cycle cost.Compared with the traditional energy network,the equipment capacity problem of energy interconnected distribution network which involves in electricity network,thermal energy network and natural gas network is comprehensively considered in this paper.On this basis,firstly,the operation architecture of energy interconnected distribution network is designed.Secondly,taking the grid connection location and configuration capacity of key equipment in the system as the control variables and the operation cost of system comprehensive planning in the whole life cycle as the goal,the equipment location and capacity optimization model of energy interconnected distribution network is established.Finally,an IEEE 33 bus energy mutual distribution grid system is taken for example analysis,and the improved chaotic particle swarmoptimization algorithm is used to solve it.The simulation results show that the method proposed in this paper is suitable for the equipment location and capacity planning of energy interconnected distribution network,and it can effectively improve the social and economic benefits of system operation.
文摘The publication of ISO 15686-5 is significant for studies related to the life-cycle costs of buildings. Among the many economic evaluation methods, the NPV method is recommended for use by this standard. This study explains the concept and method of PV, and then provides an explanation of the concept and method of NPV, and points out the limitations in the practical application of the method.
文摘With the advent of the fourth industrial revolution,the construction industry has undergone a paradigm shift.The smart construction technology market is expected to grow 12%annually in developed countries due to advanced technology investments.It is expected that businesses requiring highly sophisticated technology,for instance companies that need their old facilities upgraded,will become the main focus of the market.As building information modeling(BIM)design is becoming mandatory,such as in the Korea Public Procurement Service,researches regarding building automation,construction,and operation integration management systems based on BIM are conducted.In addition,for construction projects of over 10 billion won,design value engineering(Design VE)implementation,including life cycle cost(LCC)analysis,is mandatory at the design stage to improve quality and reduce the lifetime costs of buildings.In this study,we propose an improvement plan for LCC analysis at the design stage using the KBIMS library,which is an open BIM library developed by the Korean government and research groups.We analyze the existing LCC method,KBIMS library,and attribute information,and model the process that is applied in the LCC analysis system.This is expected to complement the LCC analysis system and improve work productivity.
文摘After the introduction of BTL (Build-Transfer-Lease) projects in 2005, most construction projects of school facilities have been implemented in BTL system. However, concern about whether the school facilities can be managed appropriately during the 20 year as operation and management period is increasing. Therefore, the necessity of reference for evaluation standard on operating costs and the establishment of LCC (life cycle costing) prediction models is coming to the fore. In this respect, the goal of this study was to extract the variables for LCC-related models and conduct analyses of the correlations of the variables using statistical analysis tool, in order to establish LCC prediction and backtracking model based on BTL project cases of school facilities. The prediction and backtracking model of LCC will be a key for budget equalization or optimum range as one way of estimating method using LCC by year and school type. In the future, it would provide the accurate reference for analyzing and managing the actual input costs against the plan and evaluating the practical cost for long-term facility management plan as the predictive management.
文摘In this article,a total life cycle cost analysis(LCCA)was developed covering two transportation systems:trucking and railway within the Gulf Cooperation Council(GCC)region.GCC region is a regional intergovernmental political and economic union consists of six countries(Saudi Arabia,Kuwait,the United Arab Emirates,Qatar,Bahrain,and Oman).In general and based on statistics,the GCC regional economy is expected to grow due to the increase in aggregate supply and demand.So,there is a need to build a solid foundation of transportation systems that can help in transforming this region into a logistics hub.Therefore,different analysis was discussed in order to be able to select more reliable and appropriate mode of shipping between the GCC.Beside the main cost factors that which includes the capital,operational,maintenance and depreciation costs.Other factors such as,border delays,emissions,noise and safety factors were added to the analysis.The results show that,shipping using trucking system can be cheaper when shipping commodities between the GCC region,but at the same time considering border delays and emission produced,railways and intermodal modal systems prove to be more reliable.Moreover,shipping bulk commodities favor the rail and intermodal systems due to the payload capacity besides the flexibility of finding the most efficient way to move the shipments between origin and destinations.