A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation system.The effects...A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation system.The effects of different operating parameters of oxidation stage including residence time(2–24 min),formic acid to sulfur molar ratio(10–150),and oxidant to sulfur molar ratio(5–35)on the sulfur removal have been studied using response surface methodology(RSM)based on Box–Behnken design.Considering the operating costs of the continuous-flow oxidation stage including chemical and electrical energy consumption,the appropriate values of operating parameters were selected as follows:residence time of 16 min,the formic acid to sulfur molar ratio of 54.47,and the oxidant to sulfur molar ratio of 8.24.In these conditions,the sulfur removal and the volume ratio of the hydrocarbon phase to the aqueous phase were 86.90%and 4.34,respectively.By drastic reduction in the chemical consumption in the oxidation stage,the volume ratio of the hydrocarbon phase to the aqueous phase was increased up to 10.Therefore,the formic acid to sulfur molar ratio and the oxidant to sulfur molar ratio were obtained 23.64 and 3.58,respectively,which lead to sulfur removal of 84.38%with considerable improvements on the operating cost of oxidation stage in comparison with the previous works.展开更多
The adoption of new technologies often represents a crucial component of firms＇ investment decisions. This paper studies a dynamic duopoly model in which two firms compete in adoption of current technology with a fur...The adoption of new technologies often represents a crucial component of firms＇ investment decisions. This paper studies a dynamic duopoly model in which two firms compete in adoption of current technology with a further new technology anticipated. Here it is assumed that the operating costs are not zero which has more explanatory power of the real world. There exist three kinds of equilibria that may occur in adoption of current technology, which mainly depends on the level of operating costs and the first-move advantage. It shows that the faster technological substitution or innovation encourages the leader to invest earlier while induces the follower to invest later. Furthermore,like the investment costs,with the increase of operating costs the follower tends to invest later while the leader tends to invest earlier ,the investment thresholds are more sensitive to the change of operating costs than that of investment costs.展开更多
This article introduces the historical evolution and the realities of china′s railway operating cost management system, then analyzes the various problems in it under current management system. And on the basis of th...This article introduces the historical evolution and the realities of china′s railway operating cost management system, then analyzes the various problems in it under current management system. And on the basis of the first two parts, the author gives proper design and advice, trying to be helpful to the great reform of the railway operating cost control system.展开更多
Ultra-low emission of nitrogen oxide(NO_(x))is an irreversible trend for the development of waste-to-energy industry.But traditional approaches to remove NO_(x) face significant challenge s,such as low denitration eff...Ultra-low emission of nitrogen oxide(NO_(x))is an irreversible trend for the development of waste-to-energy industry.But traditional approaches to remove NO_(x) face significant challenge s,such as low denitration efficiency,complex denitration system,and high investment and operating cost.Here we put forward a novel polymer non-catalytic reduction(PNCR)technology that utilized a new type of polymer agent to remove NO_(x),and the proposed PNCR technology was applied to the existing waste-to-energy plant to test the denitration performance.The PNCR technology demonstrated excellent denitration performance with a NO_(x) emission concentration of<100 mg/Nm^(3) and high denitration efficiency of>75%at the temperature range of 800-900℃,which showed the application feasibility even on the complex and unstable industrial operating conditions.In addition,PNCR and hybrid polymer/selective non-catalytic reduction(PNCR/SNCR)technology possessed remarkable economic advantages including low investment fee and low operating cost of<10 CNY per ton of municipal solid waste(MSW)compared with selective catalytic reduction(SCR)technology.The excellent denitration performance of PNCR technology forebodes a broad industrial application prospect in the field of flue gas cleaning for waste-to-energy plants.展开更多
Pollutant gases emitted from the civil jet are doing more and more harm to the environ- ment with the rapid development of the global commercial aviation transport. Low environmental impact has become a new requiremen...Pollutant gases emitted from the civil jet are doing more and more harm to the environ- ment with the rapid development of the global commercial aviation transport. Low environmental impact has become a new requirement for aircraft design. In this paper, estimation method for emis- sion in aircraft conceptual design stage is improved based on the International Civil Aviation Orga- nization （ICAO） aircraft engine emissions databank and the polynomial curve fitting methods. The greenhouse gas emission （CO2 equivalent） per seat per kilometer is proposed to measure the emis- sions. An approximate sensitive analysis and a multi-objective optimization of aircraft design for tradeoff between greenhouse effect and direct operating cost （DOC） are performed with five geom- etry variables of wing configuration and two flight operational parameters. The results indicate that reducing the cruise altitude and Mach number may result in a decrease of the greenhouse effect but an increase of DOC. And the two flight operational parameters have more effects on the emissions than the wing configuration. The Pareto-optimal front shows that a decrease of 29.8% in DOC is attained at the expense of an increase of 10.8% in greenhouse gases.展开更多
On the basis of analysis and selection of factors influencing operation cost of coal resources development, fuzzy set method and artificial neural network (ANN) were adopted to set up the classification analysis model...On the basis of analysis and selection of factors influencing operation cost of coal resources development, fuzzy set method and artificial neural network (ANN) were adopted to set up the classification analysis model of coal resources. The collected samples were classified by using this model. Meanwhile, the pattern recognition model for classifying of the coal resources was built according to the factors influencing operation cost. Based on the results achieved above, in the light of the theory of information diffusion, the calculation model for operation cost of coal resources development has been presented and applied in practice, showing that these models are reasonable.展开更多
The purpose of this paper is to approach the administrative costs in the field of education and to answer questions such as:How are administrative costs measured and evaluated?Is it taken into account in the analysis ...The purpose of this paper is to approach the administrative costs in the field of education and to answer questions such as:How are administrative costs measured and evaluated?Is it taken into account in the analysis of policy options?Administrative costs affect all areas of public education and absorb a large part of the state budget appropriations intended for education.Through the presentation of the general and specific objectives but also the European participation in the rational management of the management costs of the educational units,we lead to a holistic approach to the operational costs of the education that is part of the social costs.展开更多
The development of urban rail transit can improve the level of urban governance, reconstruct the urban spatial pattern and economic geography, and improve the quality of citizens' life, but at the same time it fac...The development of urban rail transit can improve the level of urban governance, reconstruct the urban spatial pattern and economic geography, and improve the quality of citizens' life, but at the same time it faces many problems, such as the difficulty of capital, the need to optimize the construction capacity, the pressure of super-large network operation, and the insufficient hematopoietic capacity of resource management. In terms of operation, if the cost cannot be effectively controlled, it will bring great pressure. In the process of urban rail transit entering super-large-scale network operation, deepening market-oriented transformation and reform, and realizing high-quality development, it is necessary to solve the current cost control problem, strictly control operating costs, and lay the foundation for high-quality development to a new level.展开更多
libraries are universally accepted as the symbols of college and every university invests large sum of money into libraries. According to the criteria in EUCT （Evaluation in Undergraduate Course Teaching）, college l...libraries are universally accepted as the symbols of college and every university invests large sum of money into libraries. According to the criteria in EUCT （Evaluation in Undergraduate Course Teaching）, college libraries should meet certain standards and the cost will be large. Given the current condition that governmental funding is inadequate, we have to control the cost by ourselves. Our solutions to cost control will focus on three aspects： manpower of stuffs, hardware of library and the maintenance of library.展开更多
目的对经外周置入中心静脉导管(peripherally inserted central catheter,PICC)置管、维护及拔管的单项操作成本进行核算,为制定合理的操作收费价格提供依据。方法通过横断面调查,采用项目成本阶梯分摊法,于2019年1—5月在复旦大学附属...目的对经外周置入中心静脉导管(peripherally inserted central catheter,PICC)置管、维护及拔管的单项操作成本进行核算,为制定合理的操作收费价格提供依据。方法通过横断面调查,采用项目成本阶梯分摊法,于2019年1—5月在复旦大学附属肿瘤医院血管通路门诊测算PICC各单项操作人力成本、设备折旧费及未单独计价材料费,测算直接成本,并通过分摊测算间接成本,最后测算PICC置管、维护及拔管的单项操作成本。结果PICC置管、维护及拔管的各单项操作实际成本分别为(157.03±4.73)元、(33.66±3.04)元、(32.38±3.11)元,与上海市医疗机构对PICC各项操作的收费标准(分别为150元、30元、30元)基本相符。结论建议将PICC维护及拔管的操作收费纳入收费标准中,促进PICC输液技术的可持续发展并确保护理服务的持续供给。展开更多
Equipment plays an important role in open pit mining industry and its cost competence at efficient operation and maintenance techniques centered on reliability can lead to significant cost reduction.The application of...Equipment plays an important role in open pit mining industry and its cost competence at efficient operation and maintenance techniques centered on reliability can lead to significant cost reduction.The application of optimal maintenance process was investigated for minimizing the equipment breakdowns and downtimes in Sungun Copper Mine.It results in the improved efficiency and productivity of the equipment and lowered expenses as well as the increased profit margin.The field operating data of 10 trucks are used to estimate the failure and maintenance profile for each component,and modeling and simulation are accomplished by using reliability block diagram method.Trend analysis was then conducted to select proper probabilistic model for maintenance profile.Then reliability of the system was evaluated and importance of each component was computed by weighted importance measure method.This analysis led to identify the items with critical impact on availability of overall equipment in order to prioritize improvement decisions.Later,the availability of trucks was evaluated using Monte Carlo simulation and it is revealed that the uptime of the trucks is around 11000 h at 12000 operation hours.Finally,uncertainty analysis was performed to account for the uncertainty sources in data and models.展开更多
We compare the optimal operating cost of the two bicriterion policies, <p,T> and <p,N>, for an M/G/1 queueing system with second optional service, in which the length of the vacation period is randomly con...We compare the optimal operating cost of the two bicriterion policies, <p,T> and <p,N>, for an M/G/1 queueing system with second optional service, in which the length of the vacation period is randomly controlled either by the number of arrivals during the idle period or by a timer. After all the customers are served in the queue exhaustively, the server immediately takes a vacation and may operate <p,T> policy or <p,N> policy. For the two bicriterion policies, the total average cost function per unit time is developed to search the optimal stationary operating policies at a minimum cost. Based upon the optimal cost the explicit forms for joint optimum threshold values of (p,T) and (p,N) are obtained.展开更多
Internal thermally coupled distillation column(ITCDIC) is a frontier in energy saving distillation research. In this paper, the optimal assessment on the energy saving and the operating cost for ITCDIC of nonideal mix...Internal thermally coupled distillation column(ITCDIC) is a frontier in energy saving distillation research. In this paper, the optimal assessment on the energy saving and the operating cost for ITCDIC of nonideal mixture is explored. An evaluating method is proposed, and the pertinent optimization model is then derived. The ethanol-water system is studied as an illustrative example. The optimization results show that the maximum energy saving in ITCDIC process is about 35% and the maximum operating cost saving in ITCDIC process is about 30%,as compared with a conventional distillation column(CDIC) under the minimum reflux ratio operating; the optimal operating pressure of the rectifying section is found to be around 0.25 MPa; the effects of the feed composition,operating pressure and the heat transfer rate on operation are also found and analyzed. It is revealed that ITCDIC process possesses high energy saving potential and promising economical prospect.展开更多
The beer game model is a typical paradigm used to study complex dynamics behaviours in production–distribution systems. The model, however, does not accord with current practical supply chain system models in discret...The beer game model is a typical paradigm used to study complex dynamics behaviours in production–distribution systems. The model, however, does not accord with current practical supply chain system models in discrete?type manufacturing industry, which are generally composed of retailers, distributors, manufacturers with internal sup?ply chain, and suppliers. To describe how ordering policies influence the complex dynamics behaviour modes and operating cost in a general discrete?type manufacturing industry supply chain system, a high dimension piecewise?linear dynamics model is built for the supply chain system. Five kinds of ordering policy combination are considered. The distribution of both the largest Lyapunov exponent of e ective inventory and average operating cost per cycle is obtained by simulation in a policy space. The simulation shows that for the general discrete?type manufacturing industry supply chain system, the upper chaotic corners emerge besides the lower chaotic corners in the policy space expressing the distribution of system behaviour mode, and that the ordering policies at each supply chain node as well as their combination have very significant e ect on the topology of the distribution of both system behaviour mode and operating cost in the policy space. We find that chaos is not always corresponding to high cost, and the "chaos amplification" is not completely relevant to the "cost amplification".展开更多
The Regional Integrated Energy System(RIES)has brought new modes of development,utilization,conversion,storage of energy.The introduction of Soft Open Point(SOP)and the application of Power to Gas(P2G)technology will ...The Regional Integrated Energy System(RIES)has brought new modes of development,utilization,conversion,storage of energy.The introduction of Soft Open Point(SOP)and the application of Power to Gas(P2G)technology will greatly deepen the coupling of the electricity-gas integrated energy system,improve the flexibility and safety of the operation of the power system,and bring a deal of benefits to the power system.On this background,an optimal dispatch model of RIES combined cold,heat,gas and electricity with SOP is proposed.Firstly,RIES architecture with SOP and P2G is designed and its mathematical model also is built.Secondly,on the basis of considering the optimal scheduling of combined cold,heat,gas and electricity,the optimal scheduling model for RIES was established.After that,the original model is transformed into a mixed-integer second-order cone programming model by using linearization and second-order cone relaxation techniques,and the CPLEX solver is invoked to solve the optimization problem.Finally,the modified IEEE 33-bus systemis used to analyze the benefits of SOP,P2G technology and lithium bromide absorption chillers in reducing systemnetwork loss and cost,as well as improving the system’s ability to absorb wind and solar and operating safety.展开更多
Since July 2014,when the international oil price slumped,the upstream sector of global oil and gas industry has experienced a tough transformation phase lasting over two years.In terms of the development trend,the glo...Since July 2014,when the international oil price slumped,the upstream sector of global oil and gas industry has experienced a tough transformation phase lasting over two years.In terms of the development trend,the global upstream sector has demonstrated six characteristics since 2017:firstly,global upstream investment will probably demonstrate the trend of "touching the ground and rising again";secondly,upstream operating costs will continually decline;thirdly,more favorable finance and taxation clauses will be offered for some resources to be developed through foreign cooperation;fourthly,global oil and gas output will probably further increase;fifthly,upstream exploration efficiency is anticipated to steadily increase;and sixthly,upstream geological understandings,theory and technology will continue to advance.In accordance with the above-mentioned development trends,Chinese oil enterprises must be prepared in four aspects for future rejuvenation.Firstly,persistent upstream investment has to be guaranteed,particularly in the exploration field;secondly,upstream operation efficiency must be promoted through the enhancement of technical research;thirdly,overseas upstream property must be purchased within the "time window";and fourthly,reforms have to be carried out to realize transformation in the petroleum industry.展开更多
Objective: to explore the effect of the new integrated management model of static dispensing center and central pharmacy. Methods: through consulting materials, studying and self-analysis, the integrated management wa...Objective: to explore the effect of the new integrated management model of static dispensing center and central pharmacy. Methods: through consulting materials, studying and self-analysis, the integrated management was tried out in combination with the actual situation of our hospital. Results: after the integrated management, the integration of the layout, structure, personnel allocation, drug management, dispensing pharmacists and audit work was achieved. Conclusion: through integrated management, the turnover rate of drug inventory can be increased, the operating cost of departments can be reduced, and the team cooperation ability can be improved.展开更多
For the low utilization rate of photovoltaic power generation,taking a new energy power system constisting of concentrating solar power(CSP),photovoltaic power(PP)and battery energy storage system as an example,a mult...For the low utilization rate of photovoltaic power generation,taking a new energy power system constisting of concentrating solar power(CSP),photovoltaic power(PP)and battery energy storage system as an example,a multi-objective optimization scheduling strategy considering energy storage participation is proposed.Firstly,the new energy power system model is established,and the PP scenario generation and reduction frame based on the autoregressive moving average model and Kantorovich-distance is proposed.Then,based on the optimization goal of the system operation cost minimization and the PP output power consumption maximization,the multi-objective optimization scheduling model is established.Finally,the simulation results show that introducing energy storage into the system can effectively reduce the system operation cost and improve the utilization efficiency of PP.展开更多
基金the supports provided by National Iranian Oil Engineering and Construction Company(NIOEC)。
文摘A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation system.The effects of different operating parameters of oxidation stage including residence time(2–24 min),formic acid to sulfur molar ratio(10–150),and oxidant to sulfur molar ratio(5–35)on the sulfur removal have been studied using response surface methodology(RSM)based on Box–Behnken design.Considering the operating costs of the continuous-flow oxidation stage including chemical and electrical energy consumption,the appropriate values of operating parameters were selected as follows:residence time of 16 min,the formic acid to sulfur molar ratio of 54.47,and the oxidant to sulfur molar ratio of 8.24.In these conditions,the sulfur removal and the volume ratio of the hydrocarbon phase to the aqueous phase were 86.90%and 4.34,respectively.By drastic reduction in the chemical consumption in the oxidation stage,the volume ratio of the hydrocarbon phase to the aqueous phase was increased up to 10.Therefore,the formic acid to sulfur molar ratio and the oxidant to sulfur molar ratio were obtained 23.64 and 3.58,respectively,which lead to sulfur removal of 84.38%with considerable improvements on the operating cost of oxidation stage in comparison with the previous works.
文摘The adoption of new technologies often represents a crucial component of firms＇ investment decisions. This paper studies a dynamic duopoly model in which two firms compete in adoption of current technology with a further new technology anticipated. Here it is assumed that the operating costs are not zero which has more explanatory power of the real world. There exist three kinds of equilibria that may occur in adoption of current technology, which mainly depends on the level of operating costs and the first-move advantage. It shows that the faster technological substitution or innovation encourages the leader to invest earlier while induces the follower to invest later. Furthermore,like the investment costs,with the increase of operating costs the follower tends to invest later while the leader tends to invest earlier ,the investment thresholds are more sensitive to the change of operating costs than that of investment costs.
文摘This article introduces the historical evolution and the realities of china′s railway operating cost management system, then analyzes the various problems in it under current management system. And on the basis of the first two parts, the author gives proper design and advice, trying to be helpful to the great reform of the railway operating cost control system.
基金supported by the National Natural Science Foundation of China(No.92367107)。
文摘Ultra-low emission of nitrogen oxide(NO_(x))is an irreversible trend for the development of waste-to-energy industry.But traditional approaches to remove NO_(x) face significant challenge s,such as low denitration efficiency,complex denitration system,and high investment and operating cost.Here we put forward a novel polymer non-catalytic reduction(PNCR)technology that utilized a new type of polymer agent to remove NO_(x),and the proposed PNCR technology was applied to the existing waste-to-energy plant to test the denitration performance.The PNCR technology demonstrated excellent denitration performance with a NO_(x) emission concentration of<100 mg/Nm^(3) and high denitration efficiency of>75%at the temperature range of 800-900℃,which showed the application feasibility even on the complex and unstable industrial operating conditions.In addition,PNCR and hybrid polymer/selective non-catalytic reduction(PNCR/SNCR)technology possessed remarkable economic advantages including low investment fee and low operating cost of<10 CNY per ton of municipal solid waste(MSW)compared with selective catalytic reduction(SCR)technology.The excellent denitration performance of PNCR technology forebodes a broad industrial application prospect in the field of flue gas cleaning for waste-to-energy plants.
基金supported by the Fundamental Research Funds for the Central Universities (NUAA NN2012071)China Postdoctoral Science Foundation (2011M500919)
文摘Pollutant gases emitted from the civil jet are doing more and more harm to the environ- ment with the rapid development of the global commercial aviation transport. Low environmental impact has become a new requirement for aircraft design. In this paper, estimation method for emis- sion in aircraft conceptual design stage is improved based on the International Civil Aviation Orga- nization （ICAO） aircraft engine emissions databank and the polynomial curve fitting methods. The greenhouse gas emission （CO2 equivalent） per seat per kilometer is proposed to measure the emis- sions. An approximate sensitive analysis and a multi-objective optimization of aircraft design for tradeoff between greenhouse effect and direct operating cost （DOC） are performed with five geom- etry variables of wing configuration and two flight operational parameters. The results indicate that reducing the cruise altitude and Mach number may result in a decrease of the greenhouse effect but an increase of DOC. And the two flight operational parameters have more effects on the emissions than the wing configuration. The Pareto-optimal front shows that a decrease of 29.8% in DOC is attained at the expense of an increase of 10.8% in greenhouse gases.
文摘On the basis of analysis and selection of factors influencing operation cost of coal resources development, fuzzy set method and artificial neural network (ANN) were adopted to set up the classification analysis model of coal resources. The collected samples were classified by using this model. Meanwhile, the pattern recognition model for classifying of the coal resources was built according to the factors influencing operation cost. Based on the results achieved above, in the light of the theory of information diffusion, the calculation model for operation cost of coal resources development has been presented and applied in practice, showing that these models are reasonable.
文摘The purpose of this paper is to approach the administrative costs in the field of education and to answer questions such as:How are administrative costs measured and evaluated?Is it taken into account in the analysis of policy options?Administrative costs affect all areas of public education and absorb a large part of the state budget appropriations intended for education.Through the presentation of the general and specific objectives but also the European participation in the rational management of the management costs of the educational units,we lead to a holistic approach to the operational costs of the education that is part of the social costs.
文摘The development of urban rail transit can improve the level of urban governance, reconstruct the urban spatial pattern and economic geography, and improve the quality of citizens' life, but at the same time it faces many problems, such as the difficulty of capital, the need to optimize the construction capacity, the pressure of super-large network operation, and the insufficient hematopoietic capacity of resource management. In terms of operation, if the cost cannot be effectively controlled, it will bring great pressure. In the process of urban rail transit entering super-large-scale network operation, deepening market-oriented transformation and reform, and realizing high-quality development, it is necessary to solve the current cost control problem, strictly control operating costs, and lay the foundation for high-quality development to a new level.
文摘libraries are universally accepted as the symbols of college and every university invests large sum of money into libraries. According to the criteria in EUCT （Evaluation in Undergraduate Course Teaching）, college libraries should meet certain standards and the cost will be large. Given the current condition that governmental funding is inadequate, we have to control the cost by ourselves. Our solutions to cost control will focus on three aspects： manpower of stuffs, hardware of library and the maintenance of library.
文摘目的对经外周置入中心静脉导管(peripherally inserted central catheter,PICC)置管、维护及拔管的单项操作成本进行核算,为制定合理的操作收费价格提供依据。方法通过横断面调查,采用项目成本阶梯分摊法,于2019年1—5月在复旦大学附属肿瘤医院血管通路门诊测算PICC各单项操作人力成本、设备折旧费及未单独计价材料费,测算直接成本,并通过分摊测算间接成本,最后测算PICC置管、维护及拔管的单项操作成本。结果PICC置管、维护及拔管的各单项操作实际成本分别为(157.03±4.73)元、(33.66±3.04)元、(32.38±3.11)元,与上海市医疗机构对PICC各项操作的收费标准(分别为150元、30元、30元)基本相符。结论建议将PICC维护及拔管的操作收费纳入收费标准中,促进PICC输液技术的可持续发展并确保护理服务的持续供给。
基金the support of the Maintenance Department of Mobin Co.Sungun Copper mine
文摘Equipment plays an important role in open pit mining industry and its cost competence at efficient operation and maintenance techniques centered on reliability can lead to significant cost reduction.The application of optimal maintenance process was investigated for minimizing the equipment breakdowns and downtimes in Sungun Copper Mine.It results in the improved efficiency and productivity of the equipment and lowered expenses as well as the increased profit margin.The field operating data of 10 trucks are used to estimate the failure and maintenance profile for each component,and modeling and simulation are accomplished by using reliability block diagram method.Trend analysis was then conducted to select proper probabilistic model for maintenance profile.Then reliability of the system was evaluated and importance of each component was computed by weighted importance measure method.This analysis led to identify the items with critical impact on availability of overall equipment in order to prioritize improvement decisions.Later,the availability of trucks was evaluated using Monte Carlo simulation and it is revealed that the uptime of the trucks is around 11000 h at 12000 operation hours.Finally,uncertainty analysis was performed to account for the uncertainty sources in data and models.
文摘We compare the optimal operating cost of the two bicriterion policies, <p,T> and <p,N>, for an M/G/1 queueing system with second optional service, in which the length of the vacation period is randomly controlled either by the number of arrivals during the idle period or by a timer. After all the customers are served in the queue exhaustively, the server immediately takes a vacation and may operate <p,T> policy or <p,N> policy. For the two bicriterion policies, the total average cost function per unit time is developed to search the optimal stationary operating policies at a minimum cost. Based upon the optimal cost the explicit forms for joint optimum threshold values of (p,T) and (p,N) are obtained.
基金Supported by National Natural Science Foundation of China(No.20106008)China Postdoctoral Science Foundation,Tsinghua University-Zhongda Group Postdoctoral Science Foundationthe National Environmental Protect Bureau of China(Huan-Ke-Ke,1997,
文摘Internal thermally coupled distillation column(ITCDIC) is a frontier in energy saving distillation research. In this paper, the optimal assessment on the energy saving and the operating cost for ITCDIC of nonideal mixture is explored. An evaluating method is proposed, and the pertinent optimization model is then derived. The ethanol-water system is studied as an illustrative example. The optimization results show that the maximum energy saving in ITCDIC process is about 35% and the maximum operating cost saving in ITCDIC process is about 30%,as compared with a conventional distillation column(CDIC) under the minimum reflux ratio operating; the optimal operating pressure of the rectifying section is found to be around 0.25 MPa; the effects of the feed composition,operating pressure and the heat transfer rate on operation are also found and analyzed. It is revealed that ITCDIC process possesses high energy saving potential and promising economical prospect.
基金Supported by National Natural Science Foundation of China(Grant No.11072192)Shaanxi Provincial Industrial Technology Research Projects of China(Grant No.2015GY118)
文摘The beer game model is a typical paradigm used to study complex dynamics behaviours in production–distribution systems. The model, however, does not accord with current practical supply chain system models in discrete?type manufacturing industry, which are generally composed of retailers, distributors, manufacturers with internal sup?ply chain, and suppliers. To describe how ordering policies influence the complex dynamics behaviour modes and operating cost in a general discrete?type manufacturing industry supply chain system, a high dimension piecewise?linear dynamics model is built for the supply chain system. Five kinds of ordering policy combination are considered. The distribution of both the largest Lyapunov exponent of e ective inventory and average operating cost per cycle is obtained by simulation in a policy space. The simulation shows that for the general discrete?type manufacturing industry supply chain system, the upper chaotic corners emerge besides the lower chaotic corners in the policy space expressing the distribution of system behaviour mode, and that the ordering policies at each supply chain node as well as their combination have very significant e ect on the topology of the distribution of both system behaviour mode and operating cost in the policy space. We find that chaos is not always corresponding to high cost, and the "chaos amplification" is not completely relevant to the "cost amplification".
基金Project Supported by National Natural Science Foundation of China(51777193).
文摘The Regional Integrated Energy System(RIES)has brought new modes of development,utilization,conversion,storage of energy.The introduction of Soft Open Point(SOP)and the application of Power to Gas(P2G)technology will greatly deepen the coupling of the electricity-gas integrated energy system,improve the flexibility and safety of the operation of the power system,and bring a deal of benefits to the power system.On this background,an optimal dispatch model of RIES combined cold,heat,gas and electricity with SOP is proposed.Firstly,RIES architecture with SOP and P2G is designed and its mathematical model also is built.Secondly,on the basis of considering the optimal scheduling of combined cold,heat,gas and electricity,the optimal scheduling model for RIES was established.After that,the original model is transformed into a mixed-integer second-order cone programming model by using linearization and second-order cone relaxation techniques,and the CPLEX solver is invoked to solve the optimization problem.Finally,the modified IEEE 33-bus systemis used to analyze the benefits of SOP,P2G technology and lithium bromide absorption chillers in reducing systemnetwork loss and cost,as well as improving the system’s ability to absorb wind and solar and operating safety.
文摘Since July 2014,when the international oil price slumped,the upstream sector of global oil and gas industry has experienced a tough transformation phase lasting over two years.In terms of the development trend,the global upstream sector has demonstrated six characteristics since 2017:firstly,global upstream investment will probably demonstrate the trend of "touching the ground and rising again";secondly,upstream operating costs will continually decline;thirdly,more favorable finance and taxation clauses will be offered for some resources to be developed through foreign cooperation;fourthly,global oil and gas output will probably further increase;fifthly,upstream exploration efficiency is anticipated to steadily increase;and sixthly,upstream geological understandings,theory and technology will continue to advance.In accordance with the above-mentioned development trends,Chinese oil enterprises must be prepared in four aspects for future rejuvenation.Firstly,persistent upstream investment has to be guaranteed,particularly in the exploration field;secondly,upstream operation efficiency must be promoted through the enhancement of technical research;thirdly,overseas upstream property must be purchased within the "time window";and fourthly,reforms have to be carried out to realize transformation in the petroleum industry.
文摘Objective: to explore the effect of the new integrated management model of static dispensing center and central pharmacy. Methods: through consulting materials, studying and self-analysis, the integrated management was tried out in combination with the actual situation of our hospital. Results: after the integrated management, the integration of the layout, structure, personnel allocation, drug management, dispensing pharmacists and audit work was achieved. Conclusion: through integrated management, the turnover rate of drug inventory can be increased, the operating cost of departments can be reduced, and the team cooperation ability can be improved.
基金Science and Technology Project of State Grid Corporation of China(No.SGGSKY00FJJS1800140)。
文摘For the low utilization rate of photovoltaic power generation,taking a new energy power system constisting of concentrating solar power(CSP),photovoltaic power(PP)and battery energy storage system as an example,a multi-objective optimization scheduling strategy considering energy storage participation is proposed.Firstly,the new energy power system model is established,and the PP scenario generation and reduction frame based on the autoregressive moving average model and Kantorovich-distance is proposed.Then,based on the optimization goal of the system operation cost minimization and the PP output power consumption maximization,the multi-objective optimization scheduling model is established.Finally,the simulation results show that introducing energy storage into the system can effectively reduce the system operation cost and improve the utilization efficiency of PP.
