This study delves into the formation dynamics of alliances within a closed-loop supply chain(CLSC)that encom-passes a manufacturer,a retailer,and an e-commerce platform.It leverages Stackelberg game for this explorati...This study delves into the formation dynamics of alliances within a closed-loop supply chain(CLSC)that encom-passes a manufacturer,a retailer,and an e-commerce platform.It leverages Stackelberg game for this exploration,contrasting the equilibrium outcomes of a non-alliance model with those of three differentiated alliance models.The non-alliance model acts as a crucial benchmark,enabling the evaluation of the motivations for various supply chain entities to engage in alliance formations.Our analysis is centered on identifying the most effective alliance strategies and establishing a coordination within these partnerships.We thoroughly investigate the consequences of diverse alliance behaviors,bidirectional free-riding and cost-sharing,and the resultant effects on the optimal decision-making among supply chain actors.The findings underscore several pivotal insights:(1)The behavior of alliances within the supply chain exerts variable impacts on the optimal pricing and demand of its members.In comparison to the non-alliance(D)model,the manufacturer-retailer(MR)and manufacturer-e-commerce platform(ME)alliances significantly lower both offline and online resale prices for new and remanufactured goods.This adjustment leads to an enhanced demand for products via the MR alliance’s offline outlets and the ME alliance’s online platforms,thereby augmenting the profits for those within the alliance.Conversely,retailer-e-commerce platform(ER)alliance tends to increase the optimal retail price and demand across both online and offline channels.Under specific conditions,alliance behavior can also increase the profits of non-alliance members,and the profits derived through alliance channels also exceed those from non-alliance channels.(2)The prevalence of bidirectional free-riding behavior largely remains constant across different alliance configurations.Across these models,bidirectional free-riding typically elevates the equilibrium prices in offline channel while negatively affecting the equilibrium prices in other channel.(3)The effect of cost-sharing shows relative uniformity across the various alliance models.Across all configurations,cost-sharing tends to reduce the manufacturer’s profits.Nonetheless,alliances initiated by the manufacturer can counteract these negative impacts,providing a strategic pathway to bolster CLSC profitability.展开更多
This article proposes a dual-negative-objective coordinated control strategy for brushless doubly fed induction generator(BDFIG)based wind power generation system under unbalanced grid voltage.To alleviate the mechani...This article proposes a dual-negative-objective coordinated control strategy for brushless doubly fed induction generator(BDFIG)based wind power generation system under unbalanced grid voltage.To alleviate the mechanical stress and impaction on rotating shaft,the negative control objective(NCO)of machine side converter(MSC)is set to suppress the ripple of electromagnetic torque.While the NCO of grid side converter(GSC)is selected to suppress the oscillation of total output active power or the unbalanced degree of total output current for BDFIG generation system.In comparison with traditional single converter control scheme of the MSC or GSC,dual NCOs can be satisfied at the same time due to the enlarged freedom degree in the proposed improved coordinated control system for back-toback converters.The effectiveness of proposed control strategy is validated by simulation and experimental results on a dual-cagerotor BDFIG(DCR-BDFIG)prototype.展开更多
The green and low carbon transition and development of the electricity industry is the most crucial task in realizing the“dual-carbon target”,and it is urgent to explore the incentive and subsidy mechanism to promot...The green and low carbon transition and development of the electricity industry is the most crucial task in realizing the“dual-carbon target”,and it is urgent to explore the incentive and subsidy mechanism to promote green electricity consumption and the cost-sharing strategy of carbon reduction,to alleviate the pressure of carbon abatement cost of each subject of the electricity supply chain.Against this background,this paper takes into account the low-carbon subsidies provided by the government and the incentive subsidies for users,and studies the optimal decision-making of each subject in the electricity supply chain,so that each of them can obtain the optimal profit and achieve carbon emission reduction at the same time.Firstly,taking into account the direct power purchase mode of large users and the electricity-selling companies emerging after the reform of the power sales side,we have established a cooperative mechanism for sharing the cost of carbon emission reduction in the electricity supply chain and clarified the relationship between the supply and demand of electricity among the main parties.Subsequently,considering government low-carbon subsidies and user incentive subsidies,the optimal decisionmaking model is established under two scenarios of decentralized and centralized cooperative games in the supply chain,respectively,with the objective of maximizing profits and carbon reduction rates.Solving for the optimal proportion of carbon abatement costs shared by each participant in the electricity supply chain in achieving game equilibrium.Finally,we analyze the role of the government’s low-carbon subsidies,users’incentive subsidies,and other factors on the profit and carbon reduction effect of the electricity industry through the example analysis and further analyze the impact of carbon abatement cost-sharing measures to provide recommendations for the electricity industry to realize low-carbon abatement and make decisions.展开更多
In operations research, the transportation problem (TP) is among the earliest and most effective applications of the linear programming problem. Unbalanced transportation problems reflect the reality of supply chain a...In operations research, the transportation problem (TP) is among the earliest and most effective applications of the linear programming problem. Unbalanced transportation problems reflect the reality of supply chain and logistics situations where the available supply of goods may not precisely match the demand at different locations. To deal with an unbalanced transportation problem (UTP), it is essential first to convert it into a balanced transportation problem (BTP) to find an initial basic feasible solution (IBFS) and hence the optimal solution. The present paper is concerned with introducing a new approach to convert an unbalanced transportation problem into a balanced one and as a consequence to obtain optimum total transportation cost. Numerical examples are provided to demonstrate the suggested method.展开更多
This paper presents an extensive survey of the most commonly used tools for diagnosing unbalanced flow in the atmosphere, namely the Lagrangian Rossby number, Psi vector, divergence equation, nonlinear balance equatio...This paper presents an extensive survey of the most commonly used tools for diagnosing unbalanced flow in the atmosphere, namely the Lagrangian Rossby number, Psi vector, divergence equation, nonlinear balance equation, generalized omega-equation, and departure from fields obtained by potential vorticity (PV) inversion. The basic thoery, assumptions as well as implementation and limitations for each of the tools are all discussed. These tools are applied to high—resolution mesoscale model data to assess the role of unbalanced dynamics in the generation of a mesoscale gravity wave event over the East Coast of the United States. Comparison of these tools in this case study shows that these various methods agree to a large extent with each other though they differ in details. Key words Unbalanced flow - Geostrophic adjustment - Gravity waves - Nonlinear balance equation - Potential vorticity inversion - Omega equations - Rossby number This research was conducted under support from NSF grant ATM-9700626 of the United States. The numerical computations described herein were performed on the Cray T90 at the North Carolina Supercomputing Center and the Cray supercomputer at the NCAR Scientific Computing Division, which also provided the initialization fields for the MM5. Thanks are extended to Mark Stoelinga at University of Washington for the RIP post-processing package.展开更多
Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods. Unbalanced magnetron sputterin...Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods. Unbalanced magnetron sputtering, by producing dense secondary plasma around the substrate, provides a high ion current density. The closed-field unbalanced magnetron sputtering system （CFUBMS） has been established as a versatile technique for high-rate deposition high-quality metal, alloy, and ceramic thin films. The＇key factor in the CFUBMS system is the ability to transport high ion currents to the substrate, which can enhance the formation of full dense coatings at relatively low value homologous temperature. The investigation shows that the energy of ions incidenced at the substrate and the ratio of the flux of these ions to the flux of condensing atoms are the fundamental parameters in determining the structure and properties of films produced by ion-assisted deposition processes. Increasing ion bombardment during deposition combined with increasing mobility of the condensing atoms favors the formation of a dense microstructure and a smooth surface.展开更多
A structure iterated by the unbalanced Feistel networks is introduced. It is showed that this structure is provable resistant against linear attack. The main result of this paper is that the upper bound of r-round （r...A structure iterated by the unbalanced Feistel networks is introduced. It is showed that this structure is provable resistant against linear attack. The main result of this paper is that the upper bound of r-round （r≥2m） linear hull probabilities are bounded by q^2 when around function F is bijective and the maximal linear hull probabilities of round function F is q. Application of this structure to block cipher designs brings out the provable security against linear attack with the upper bounds of probabilities.展开更多
To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each ...To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each stage, the Pruefer number is used. With theimproved decoding procedure, any Pruefer number produced stochastically can be decoded to a feasiblelogistic pattern, which can match with the capacities of the nodes of the logistic system. Withthese two innovations, a new modeling method based on parameterized interface distribution and thePriifer number coding is put forward. The corresponding genetic algorithm, named as PIP-GA, can findbetter solutions and require less computational time than st-GA. Although requiring a little moreconsumption of memory, PIP-GA is still an efficient and robust method in the modeling andoptimization of unbalanced multi-stage logistic systems.展开更多
For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machi...For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared transmission.By using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and examined.The results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining accuracy.And the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges.展开更多
The effect of unbalanced coefficient of magnetron （UCM） on the structure and tribological properties of CrNx hard coatings was studied.The CrNx coatings were deposited on both Si wafer and hardened tool steel substr...The effect of unbalanced coefficient of magnetron （UCM） on the structure and tribological properties of CrNx hard coatings was studied.The CrNx coatings were deposited on both Si wafer and hardened tool steel substrates using a closed-field unbalanced magnetron sputtering ion plating technique in a gas mixture of Ar＋N2 under different unbalanced magnetron conditions.The coatings were characterized by means of XRD,XPS,SEM,microhardness tester and pin-on-disc tribometer to study respectively their structure,chemical bonding state,microstructure,hardness and tribological properties.The experimental results show that the UCM has a profound effect on the structure,hardness and tribological properties of the CrNx coatings.With increasing the values of UCM,the dominant phases in the deposited coatings evolved from Cr＋Cr2N to Cr2N＋CrN,the microstructure became denser and the hardness increased;in addition,reduced coefficient of friction and improved wear resistance of CrNx coatings were also observed under a larger UCM.展开更多
The Vienna rectifier with unbalanced input voltage and load transient is analyzed.A nonlinear control strategy for Vienna rectifier under unbalanced input is proposed.From the view of positive and negative sequence co...The Vienna rectifier with unbalanced input voltage and load transient is analyzed.A nonlinear control strategy for Vienna rectifier under unbalanced input is proposed.From the view of positive and negative sequence components,the proposed nonlinear control strategy suppresses the twice frequency ripple and guarantees the dynamic response characteristic at the same time.Thanks to the proposed nonlinear control strategy,the DC bus capacitor can be reduced a lot since the voltage ripple and drop can be suppressed.A 10 kW Vienna rectifier is built to verify the proposed control strategy.After applying the proposed nonlinear control strategy,the voltage ripple is only7 V and decreases over 75%over the traditional PI control when the unbalanced degree is 20%.The voltage drop can be reduced about 80%than former control strategy which is helpful to reduce the DC bus capacitor and achieve higher power density.The volume of the capacitor can be reduced by 83.3%with the new control method.展开更多
Metallic copper（Cu） films were deposited on a Si （100） substrate by unbalanced magnetron sputtering enhanced by radio-frequency plasma and external magnetic field confinement. The morphology and structure of the f...Metallic copper（Cu） films were deposited on a Si （100） substrate by unbalanced magnetron sputtering enhanced by radio-frequency plasma and external magnetic field confinement. The morphology and structure of the films were examined by scanning electron microscopy （SEM）, atomic force microscope （AFM） and X-ray diffraction （XRD）. The surface average roughness of the deposited Cu films was characterized by AFM data and resistivity was measured by a four-point probe. The results show that the Cu films deposited with radio-frequency discharge enhanced ionization and external magnetic field confinement have a smooth surface, low surface roughness and low resistivity. The reasons may be that the radio-frequency discharge and external magnetic field enhance the plasma density, which further improves the ion bombardment effect under the same bias voltage conditions. Ion bombardment can obviously influence the growth features and characteristics of the deposited Cu films.展开更多
A novel fuzzy support vector machine based on unbalanced samples(FSVM-US)is proposed to solve the high false positive rate problem since the gyroscope output is susceptible to unmanned aerial vehicle(UAV)airborne elec...A novel fuzzy support vector machine based on unbalanced samples(FSVM-US)is proposed to solve the high false positive rate problem since the gyroscope output is susceptible to unmanned aerial vehicle(UAV)airborne electromagnetic environment and the gyroscope abnormal signal sample is rather rare.Firstly,the standard deviation of samples projection to normal vector for SVM classifier hyper plane is analyzed.The imbalance feature expression reflecting the hyper plane shift for the number imbalance between samples and the dispersion imbalance within samples is derived.At the same time,the denoising factor is designed as the exponential decay function based on the Euclidean distance between each sample and the class center.Secondly,the imbalance feature expression and denoising factor are configured into the membership function.Each sample has its own weight denoted the importance to the classifier.Finally,the classification simulation experiments on the gyroscope fault diagnosis system are conducted and FSVM-US is compared with the standard SVM,FSVM,and the four typical class imbalance learning(CIL)methods.The results show that FSVM-US classifier accuracy is 12% higher than that of the standard SVM.Generally,FSVM-US is superior to the four CIL methods in total performance.Moreover,the FSVMUS noise tolerance is also 17% higher than that of the standard SVM.展开更多
This paper presents a unified positive-and negative-sequence dual-dq dynamic model of wind-turbine driven doubly-fed induction generator(DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control ...This paper presents a unified positive-and negative-sequence dual-dq dynamic model of wind-turbine driven doubly-fed induction generator(DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control and operation of a DFIG-used back-to-back(BTB) PWM voltage source converter(VSC) are proposed. The modified control design for the grid-side converter in the stationary αβ frames diminishes the amplitude of DC-link voltage ripples of twice the grid frequency,and the two proposed control targets for the rotor-side converter are alternatively achieved,which,as a result,improve the fault-ride through(FRT) capability of the DFIG based wind power generation systems during unbalanced network supply. A complete unbalanced control scheme with both grid-and rotor-side converters included is designed. Finally,simulation was carried out on a 1.5 MW wind-turbine driven DFIG system and the validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results.展开更多
Diamond-like carbon （DLC） films are deposited by the Hall ion source assisted by the mid-frequency unbalanced magnetron sputtering technique. The effects of the substrate voltage bias, the substrate temperature, the...Diamond-like carbon （DLC） films are deposited by the Hall ion source assisted by the mid-frequency unbalanced magnetron sputtering technique. The effects of the substrate voltage bias, the substrate temperature, the Hall discharging current and the argon/nitrogen ratio on the DLC film＇s performance were studied. The experimental results show that the film＇s surface roughness, the hardness and the Young＇s modulus increase firstly and then decrease with the bias voltage incrementally increases. Also when the substrate temperature rises, the surface roughness of the film varies slightly, but its hardness and Young＇s modulus firstly increase followed by a sharp decrease when the temperature surpassing 120 ℃. With the Hall discharging current incrementally rising, the hardness and Young＇s modulus of the film decrease and the surface roughness of the film on 316L stainless steel firstly decreased and then remains constant.展开更多
Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering pr...Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering protocol (DSCP) was proposed to solve the data gathering problem in this scenario.In DSCP,a node evaluates the potential lifetime of the network (from its local point of view) assuming that it acts as the cluster head,and claims to be a tentative cluster head if it maximizes the potential lifetime.When evaluating the potential lifetime of the network,a node considers not only its remaining energy,but also other factors including its traffic load,the number of its neighbors,and the traffic loads of its neighbors.A tentative cluster head becomes a final cluster head with a probability inversely proportional to the number of tentative cluster heads that cover its neighbors.The protocol can terminate in O(n/lg n) steps,and its total message complexity is O(n2/lg n).Simulation results show that DSCP can effectively prolong the lifetime of the network in multi-hop networks with unbalanced traffic load.Compared with EECT,the network lifetime is prolonged by 56.6% in average.展开更多
In recent years, financial crises of higher education have become universal. The policy of cost-sharing by in- dividuals was tried out in many countries. However, empirical studies have shown that the policy has, to a...In recent years, financial crises of higher education have become universal. The policy of cost-sharing by in- dividuals was tried out in many countries. However, empirical studies have shown that the policy has, to a certain de- gree, negative effects for the poor in accepting higher education costs. This paper points out it is the mismatch between tuition fees and the ability to pay that causes the problem. Using two dimensions of group and time to pay, a mode sys- tem, including seven modes for the individual to share the cost of higher education, was constructed. It is suggested that only three modes of pay-immediately have been carried out in China and they all have same shortcomings. To try new modes and exercise different modes synthetically will be meaningful for solving the questions that exist in the current policy.展开更多
This paper proposes an analysis and a direct power control (DPC) design of a wind turbine driven doubly-fed induction generator (DFIG) under unbalanced network voltage conditions. A DFIG model described in the positiv...This paper proposes an analysis and a direct power control (DPC) design of a wind turbine driven doubly-fed induction generator (DFIG) under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions.展开更多
Up-scaled deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAIN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four mag...Up-scaled deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAIN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four magnetrons that are arranged by unbalanced magnets to form closed magnetic field enabling the system running in high current density. Elemental metals of Cr, Ti and Al are used as the target materials which are co-deposited with nitrogen forming multialloy nitride, nanoscale multi-layer or superlattice hard coatings. The substrate turntable is desfgned as planet rotation mechanism with three folds so that components or tools with complicate geometry can be uniformly coated onto all their surfaces and cutting edges. The power units for the magnetrons are straight dc whilst the substrate is biased by pulsed dc. Two solid heaters are installed in the system to enable running a wide range of deposition temperature from 200°C to 500°C. The pumping system is powerful that incorporated with a polycold to pump the system to a good vacuum in a very short time. A front door and a movable substrate table are available to benefit easily loading and unloading. Deposition procedure, properties and performance of the coatings is also presented in this paper.展开更多
This paper develops a flexible power regulation and limitation strategy of voltage source inverters(VSIs)under unbalanced grid faults.When the classical power theory is used under unbalanced grid faults,the power osci...This paper develops a flexible power regulation and limitation strategy of voltage source inverters(VSIs)under unbalanced grid faults.When the classical power theory is used under unbalanced grid faults,the power oscillations and current distortions are inevitable.In the proposed strategy,the extended power theory is introduced to compute the power feedbacks together with the classical power theory.Based on the combination of the classical and extended power theory,the proposed strategy can achieve the sinusoidal current provision and the flexible regulation between three common targets,i.e.,constant active power,balanced current,and constant reactive power.Meanwhile,the proposed strategy is associated with a power limiter,which is capable to keep the currents under the pre-defined threshold and to compute the maximum apparent power for better utilization of the inverter capacity.With this power limiter,the rated inverter capacity is fully used for both the active and reactive power provisions under unbalanced grid faults.Using the proposed power regulation and limitation,the VSI can avoid overcurrent tripping and flexibly regulate its power under unbalanced grid faults.All the conclusions are verified by the real-time hardware-in-loop tests.展开更多
基金This work was supported by the Humanities and Social Science Fund of Ministry of Education of China(No.20YJA630009)Shandong Natural Science Foundation of China(No.ZR2022MG002).
文摘This study delves into the formation dynamics of alliances within a closed-loop supply chain(CLSC)that encom-passes a manufacturer,a retailer,and an e-commerce platform.It leverages Stackelberg game for this exploration,contrasting the equilibrium outcomes of a non-alliance model with those of three differentiated alliance models.The non-alliance model acts as a crucial benchmark,enabling the evaluation of the motivations for various supply chain entities to engage in alliance formations.Our analysis is centered on identifying the most effective alliance strategies and establishing a coordination within these partnerships.We thoroughly investigate the consequences of diverse alliance behaviors,bidirectional free-riding and cost-sharing,and the resultant effects on the optimal decision-making among supply chain actors.The findings underscore several pivotal insights:(1)The behavior of alliances within the supply chain exerts variable impacts on the optimal pricing and demand of its members.In comparison to the non-alliance(D)model,the manufacturer-retailer(MR)and manufacturer-e-commerce platform(ME)alliances significantly lower both offline and online resale prices for new and remanufactured goods.This adjustment leads to an enhanced demand for products via the MR alliance’s offline outlets and the ME alliance’s online platforms,thereby augmenting the profits for those within the alliance.Conversely,retailer-e-commerce platform(ER)alliance tends to increase the optimal retail price and demand across both online and offline channels.Under specific conditions,alliance behavior can also increase the profits of non-alliance members,and the profits derived through alliance channels also exceed those from non-alliance channels.(2)The prevalence of bidirectional free-riding behavior largely remains constant across different alliance configurations.Across these models,bidirectional free-riding typically elevates the equilibrium prices in offline channel while negatively affecting the equilibrium prices in other channel.(3)The effect of cost-sharing shows relative uniformity across the various alliance models.Across all configurations,cost-sharing tends to reduce the manufacturer’s profits.Nonetheless,alliances initiated by the manufacturer can counteract these negative impacts,providing a strategic pathway to bolster CLSC profitability.
基金supported in part by National Natural Science Foundation of China under Grant 61973073supported by Jiangsu Province Higher Education Basic Science (Natural Science) Research Project under Grant 23KJB470022
文摘This article proposes a dual-negative-objective coordinated control strategy for brushless doubly fed induction generator(BDFIG)based wind power generation system under unbalanced grid voltage.To alleviate the mechanical stress and impaction on rotating shaft,the negative control objective(NCO)of machine side converter(MSC)is set to suppress the ripple of electromagnetic torque.While the NCO of grid side converter(GSC)is selected to suppress the oscillation of total output active power or the unbalanced degree of total output current for BDFIG generation system.In comparison with traditional single converter control scheme of the MSC or GSC,dual NCOs can be satisfied at the same time due to the enlarged freedom degree in the proposed improved coordinated control system for back-toback converters.The effectiveness of proposed control strategy is validated by simulation and experimental results on a dual-cagerotor BDFIG(DCR-BDFIG)prototype.
基金supported by the Project of Philosophy and Social Science Foundation of Shanghai,China(Grant No.2020BGL011).
文摘The green and low carbon transition and development of the electricity industry is the most crucial task in realizing the“dual-carbon target”,and it is urgent to explore the incentive and subsidy mechanism to promote green electricity consumption and the cost-sharing strategy of carbon reduction,to alleviate the pressure of carbon abatement cost of each subject of the electricity supply chain.Against this background,this paper takes into account the low-carbon subsidies provided by the government and the incentive subsidies for users,and studies the optimal decision-making of each subject in the electricity supply chain,so that each of them can obtain the optimal profit and achieve carbon emission reduction at the same time.Firstly,taking into account the direct power purchase mode of large users and the electricity-selling companies emerging after the reform of the power sales side,we have established a cooperative mechanism for sharing the cost of carbon emission reduction in the electricity supply chain and clarified the relationship between the supply and demand of electricity among the main parties.Subsequently,considering government low-carbon subsidies and user incentive subsidies,the optimal decisionmaking model is established under two scenarios of decentralized and centralized cooperative games in the supply chain,respectively,with the objective of maximizing profits and carbon reduction rates.Solving for the optimal proportion of carbon abatement costs shared by each participant in the electricity supply chain in achieving game equilibrium.Finally,we analyze the role of the government’s low-carbon subsidies,users’incentive subsidies,and other factors on the profit and carbon reduction effect of the electricity industry through the example analysis and further analyze the impact of carbon abatement cost-sharing measures to provide recommendations for the electricity industry to realize low-carbon abatement and make decisions.
文摘In operations research, the transportation problem (TP) is among the earliest and most effective applications of the linear programming problem. Unbalanced transportation problems reflect the reality of supply chain and logistics situations where the available supply of goods may not precisely match the demand at different locations. To deal with an unbalanced transportation problem (UTP), it is essential first to convert it into a balanced transportation problem (BTP) to find an initial basic feasible solution (IBFS) and hence the optimal solution. The present paper is concerned with introducing a new approach to convert an unbalanced transportation problem into a balanced one and as a consequence to obtain optimum total transportation cost. Numerical examples are provided to demonstrate the suggested method.
文摘This paper presents an extensive survey of the most commonly used tools for diagnosing unbalanced flow in the atmosphere, namely the Lagrangian Rossby number, Psi vector, divergence equation, nonlinear balance equation, generalized omega-equation, and departure from fields obtained by potential vorticity (PV) inversion. The basic thoery, assumptions as well as implementation and limitations for each of the tools are all discussed. These tools are applied to high—resolution mesoscale model data to assess the role of unbalanced dynamics in the generation of a mesoscale gravity wave event over the East Coast of the United States. Comparison of these tools in this case study shows that these various methods agree to a large extent with each other though they differ in details. Key words Unbalanced flow - Geostrophic adjustment - Gravity waves - Nonlinear balance equation - Potential vorticity inversion - Omega equations - Rossby number This research was conducted under support from NSF grant ATM-9700626 of the United States. The numerical computations described herein were performed on the Cray T90 at the North Carolina Supercomputing Center and the Cray supercomputer at the NCAR Scientific Computing Division, which also provided the initialization fields for the MM5. Thanks are extended to Mark Stoelinga at University of Washington for the RIP post-processing package.
文摘Low pressure sputtering with a controlled ratio of ion flux to deposited atom flux at the condensing surface is one of the main directions of development of magnetron sputtering methods. Unbalanced magnetron sputtering, by producing dense secondary plasma around the substrate, provides a high ion current density. The closed-field unbalanced magnetron sputtering system （CFUBMS） has been established as a versatile technique for high-rate deposition high-quality metal, alloy, and ceramic thin films. The＇key factor in the CFUBMS system is the ability to transport high ion currents to the substrate, which can enhance the formation of full dense coatings at relatively low value homologous temperature. The investigation shows that the energy of ions incidenced at the substrate and the ratio of the flux of these ions to the flux of condensing atoms are the fundamental parameters in determining the structure and properties of films produced by ion-assisted deposition processes. Increasing ion bombardment during deposition combined with increasing mobility of the condensing atoms favors the formation of a dense microstructure and a smooth surface.
基金Supported by the fund of National Laboratory for Modern Communications （5143603ZDS0601）,the outstanding youth science foundation of Henan （0312001800）.
文摘A structure iterated by the unbalanced Feistel networks is introduced. It is showed that this structure is provable resistant against linear attack. The main result of this paper is that the upper bound of r-round （r≥2m） linear hull probabilities are bounded by q^2 when around function F is bijective and the maximal linear hull probabilities of round function F is q. Application of this structure to block cipher designs brings out the provable security against linear attack with the upper bounds of probabilities.
文摘To decompose an unbalanced multi-stage logistic system to multipleindependent single-stage logistic systems, a new notion of parameterized interface distribution ispresented. For encoding the logistic pattern on each stage, the Pruefer number is used. With theimproved decoding procedure, any Pruefer number produced stochastically can be decoded to a feasiblelogistic pattern, which can match with the capacities of the nodes of the logistic system. Withthese two innovations, a new modeling method based on parameterized interface distribution and thePriifer number coding is put forward. The corresponding genetic algorithm, named as PIP-GA, can findbetter solutions and require less computational time than st-GA. Although requiring a little moreconsumption of memory, PIP-GA is still an efficient and robust method in the modeling andoptimization of unbalanced multi-stage logistic systems.
基金Project(10033135-2009-11) supported by the Korean Ministry of Knowledge Economy (MKE) through HNK. Co,Ltd.
文摘For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared transmission.By using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and examined.The results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining accuracy.And the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges.
基金Funded by the National High-technology Research and Development Programm of China(No.2005AA33H010)
文摘The effect of unbalanced coefficient of magnetron （UCM） on the structure and tribological properties of CrNx hard coatings was studied.The CrNx coatings were deposited on both Si wafer and hardened tool steel substrates using a closed-field unbalanced magnetron sputtering ion plating technique in a gas mixture of Ar＋N2 under different unbalanced magnetron conditions.The coatings were characterized by means of XRD,XPS,SEM,microhardness tester and pin-on-disc tribometer to study respectively their structure,chemical bonding state,microstructure,hardness and tribological properties.The experimental results show that the UCM has a profound effect on the structure,hardness and tribological properties of the CrNx coatings.With increasing the values of UCM,the dominant phases in the deposited coatings evolved from Cr＋Cr2N to Cr2N＋CrN,the microstructure became denser and the hardness increased;in addition,reduced coefficient of friction and improved wear resistance of CrNx coatings were also observed under a larger UCM.
基金supported in part by the National Natural Science Foundation of China (Nos. 51777093 ,51722702)
文摘The Vienna rectifier with unbalanced input voltage and load transient is analyzed.A nonlinear control strategy for Vienna rectifier under unbalanced input is proposed.From the view of positive and negative sequence components,the proposed nonlinear control strategy suppresses the twice frequency ripple and guarantees the dynamic response characteristic at the same time.Thanks to the proposed nonlinear control strategy,the DC bus capacitor can be reduced a lot since the voltage ripple and drop can be suppressed.A 10 kW Vienna rectifier is built to verify the proposed control strategy.After applying the proposed nonlinear control strategy,the voltage ripple is only7 V and decreases over 75%over the traditional PI control when the unbalanced degree is 20%.The voltage drop can be reduced about 80%than former control strategy which is helpful to reduce the DC bus capacitor and achieve higher power density.The volume of the capacitor can be reduced by 83.3%with the new control method.
基金National Natural Science Foundation of China(Nos.50277003,10505005)
文摘Metallic copper（Cu） films were deposited on a Si （100） substrate by unbalanced magnetron sputtering enhanced by radio-frequency plasma and external magnetic field confinement. The morphology and structure of the films were examined by scanning electron microscopy （SEM）, atomic force microscope （AFM） and X-ray diffraction （XRD）. The surface average roughness of the deposited Cu films was characterized by AFM data and resistivity was measured by a four-point probe. The results show that the Cu films deposited with radio-frequency discharge enhanced ionization and external magnetic field confinement have a smooth surface, low surface roughness and low resistivity. The reasons may be that the radio-frequency discharge and external magnetic field enhance the plasma density, which further improves the ion bombardment effect under the same bias voltage conditions. Ion bombardment can obviously influence the growth features and characteristics of the deposited Cu films.
基金supported by the Fundamental Research Fund for the Central Universities(No.56XZA12017)
文摘A novel fuzzy support vector machine based on unbalanced samples(FSVM-US)is proposed to solve the high false positive rate problem since the gyroscope output is susceptible to unmanned aerial vehicle(UAV)airborne electromagnetic environment and the gyroscope abnormal signal sample is rather rare.Firstly,the standard deviation of samples projection to normal vector for SVM classifier hyper plane is analyzed.The imbalance feature expression reflecting the hyper plane shift for the number imbalance between samples and the dispersion imbalance within samples is derived.At the same time,the denoising factor is designed as the exponential decay function based on the Euclidean distance between each sample and the class center.Secondly,the imbalance feature expression and denoising factor are configured into the membership function.Each sample has its own weight denoted the importance to the classifier.Finally,the classification simulation experiments on the gyroscope fault diagnosis system are conducted and FSVM-US is compared with the standard SVM,FSVM,and the four typical class imbalance learning(CIL)methods.The results show that FSVM-US classifier accuracy is 12% higher than that of the standard SVM.Generally,FSVM-US is superior to the four CIL methods in total performance.Moreover,the FSVMUS noise tolerance is also 17% higher than that of the standard SVM.
基金Project (No. 50577056) supported by the National Natural ScienceFoundation of China
文摘This paper presents a unified positive-and negative-sequence dual-dq dynamic model of wind-turbine driven doubly-fed induction generator(DFIG) under unbalanced grid voltage conditions. Strategies for enhanced control and operation of a DFIG-used back-to-back(BTB) PWM voltage source converter(VSC) are proposed. The modified control design for the grid-side converter in the stationary αβ frames diminishes the amplitude of DC-link voltage ripples of twice the grid frequency,and the two proposed control targets for the rotor-side converter are alternatively achieved,which,as a result,improve the fault-ride through(FRT) capability of the DFIG based wind power generation systems during unbalanced network supply. A complete unbalanced control scheme with both grid-and rotor-side converters included is designed. Finally,simulation was carried out on a 1.5 MW wind-turbine driven DFIG system and the validity of the developed unified model and the feasibility of the proposed control strategies are all confirmed by the simulated results.
文摘Diamond-like carbon （DLC） films are deposited by the Hall ion source assisted by the mid-frequency unbalanced magnetron sputtering technique. The effects of the substrate voltage bias, the substrate temperature, the Hall discharging current and the argon/nitrogen ratio on the DLC film＇s performance were studied. The experimental results show that the film＇s surface roughness, the hardness and the Young＇s modulus increase firstly and then decrease with the bias voltage incrementally increases. Also when the substrate temperature rises, the surface roughness of the film varies slightly, but its hardness and Young＇s modulus firstly increase followed by a sharp decrease when the temperature surpassing 120 ℃. With the Hall discharging current incrementally rising, the hardness and Young＇s modulus of the film decrease and the surface roughness of the film on 316L stainless steel firstly decreased and then remains constant.
基金Projects(61173169,61103203)supported by the National Natural Science Foundation of ChinaProject(NCET-10-0798)supported by the Program for New Century Excellent Talents in University of ChinaProject supported by the Post-doctoral Program and the Freedom Explore Program of Central South University,China
文摘Energy-efficient data gathering in multi-hop wireless sensor networks was studied,considering that different node produces different amounts of data in realistic environments.A novel dominating set based clustering protocol (DSCP) was proposed to solve the data gathering problem in this scenario.In DSCP,a node evaluates the potential lifetime of the network (from its local point of view) assuming that it acts as the cluster head,and claims to be a tentative cluster head if it maximizes the potential lifetime.When evaluating the potential lifetime of the network,a node considers not only its remaining energy,but also other factors including its traffic load,the number of its neighbors,and the traffic loads of its neighbors.A tentative cluster head becomes a final cluster head with a probability inversely proportional to the number of tentative cluster heads that cover its neighbors.The protocol can terminate in O(n/lg n) steps,and its total message complexity is O(n2/lg n).Simulation results show that DSCP can effectively prolong the lifetime of the network in multi-hop networks with unbalanced traffic load.Compared with EECT,the network lifetime is prolonged by 56.6% in average.
文摘In recent years, financial crises of higher education have become universal. The policy of cost-sharing by in- dividuals was tried out in many countries. However, empirical studies have shown that the policy has, to a certain de- gree, negative effects for the poor in accepting higher education costs. This paper points out it is the mismatch between tuition fees and the ability to pay that causes the problem. Using two dimensions of group and time to pay, a mode sys- tem, including seven modes for the individual to share the cost of higher education, was constructed. It is suggested that only three modes of pay-immediately have been carried out in China and they all have same shortcomings. To try new modes and exercise different modes synthetically will be meaningful for solving the questions that exist in the current policy.
基金Project (No. 50577056) supported by the National Natural Science Foundation of China
文摘This paper proposes an analysis and a direct power control (DPC) design of a wind turbine driven doubly-fed induction generator (DFIG) under unbalanced network voltage conditions. A DFIG model described in the positive and negative synchronous reference frames is presented. Variations of the stator output active and reactive powers are fully deduced in the presence of negative sequence supply voltage and rotor flux. An enhanced DPC scheme is proposed to eliminate stator active power oscillation during network unbalance. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor currents. Simulation results using PSCAD/EMTDC are presented on a 2-MW DFIG wind power generation system to validate the feasibility of the proposed control scheme under balanced and unbalanced network conditions.
文摘Up-scaled deposition process of Teer-UDP850/4 has been established and used for massive production of CrTiAIN hard coatings in applications of anti-wear, cutting and forming tools. This deposition system uses four magnetrons that are arranged by unbalanced magnets to form closed magnetic field enabling the system running in high current density. Elemental metals of Cr, Ti and Al are used as the target materials which are co-deposited with nitrogen forming multialloy nitride, nanoscale multi-layer or superlattice hard coatings. The substrate turntable is desfgned as planet rotation mechanism with three folds so that components or tools with complicate geometry can be uniformly coated onto all their surfaces and cutting edges. The power units for the magnetrons are straight dc whilst the substrate is biased by pulsed dc. Two solid heaters are installed in the system to enable running a wide range of deposition temperature from 200°C to 500°C. The pumping system is powerful that incorporated with a polycold to pump the system to a good vacuum in a very short time. A front door and a movable substrate table are available to benefit easily loading and unloading. Deposition procedure, properties and performance of the coatings is also presented in this paper.
基金This work is supported by the National Key Research and Development Program of China under Project 2021YFB2601600。
文摘This paper develops a flexible power regulation and limitation strategy of voltage source inverters(VSIs)under unbalanced grid faults.When the classical power theory is used under unbalanced grid faults,the power oscillations and current distortions are inevitable.In the proposed strategy,the extended power theory is introduced to compute the power feedbacks together with the classical power theory.Based on the combination of the classical and extended power theory,the proposed strategy can achieve the sinusoidal current provision and the flexible regulation between three common targets,i.e.,constant active power,balanced current,and constant reactive power.Meanwhile,the proposed strategy is associated with a power limiter,which is capable to keep the currents under the pre-defined threshold and to compute the maximum apparent power for better utilization of the inverter capacity.With this power limiter,the rated inverter capacity is fully used for both the active and reactive power provisions under unbalanced grid faults.Using the proposed power regulation and limitation,the VSI can avoid overcurrent tripping and flexibly regulate its power under unbalanced grid faults.All the conclusions are verified by the real-time hardware-in-loop tests.
