Space applications have raised the demand on autonomy, security and reliability for current transportation vehicle, which require guidance technology of vehicle must have strong robustness and adaptability. Therefore,...Space applications have raised the demand on autonomy, security and reliability for current transportation vehicle, which require guidance technology of vehicle must have strong robustness and adaptability. Therefore, it is needed to research exoatmospheric autonomous iterative guidance method with stronger adaptivity and higher accuracy. Based on preliminary research results, two new iterative models with performance index of maximum terminal energy for exoatmospheric autonomous iterative guidance method are proposed in this paper. Then comparative analysis between preliminary research iterative model and two new iterative models proposed is performed. The results demonstrate that the inner update iterative model proposed is the least sensitive to initial values and have the best convergence and performance in the three iterative models.展开更多
Most inverse reservoir modeling techniques require many forward simulations, and the posterior models cannot preserve geological features of prior models. This study proposes an iterative static modeling approach that...Most inverse reservoir modeling techniques require many forward simulations, and the posterior models cannot preserve geological features of prior models. This study proposes an iterative static modeling approach that utilizes dynamic data for rejecting an unsuitable training image(TI) among a set of TI candidates and for synthesizing history-matched pseudo-soft data. The proposed method is applied to two cases of channelized reservoirs, which have uncertainty in channel geometry such as direction, amplitude, and width. Distance-based clustering is applied to the initial models in total to select the qualified models efficiently. The mean of the qualified models is employed as a history-matched facies probability map in the next iteration of static models. Also, the most plausible TI is determined among TI candidates by rejecting other TIs during the iteration. The posterior models of the proposed method outperform updated models of ensemble Kalman filter(EnKF) and ensemble smoother(ES) because they describe the true facies connectivity with bimodal distribution and predict oil and water production with a reasonable range of uncertainty. In terms of simulation time, it requires 30 times of forward simulation in history matching, while the EnKF and ES need 9000 times and 200 times, respectively.展开更多
This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time ...This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time of the astronauts properly. A domain model is developed by using the ontology theory to describe the concepts, constraints and relations of the planning domain formally, abstractly and normatively. A method based on time iteration is adopted to solve the short-term planning problem. Meanwhile, the resolving strategies are proposed to resolve different kinds of conflicts induced by the constraints of power, heat, resource, astronaut and relationship. The proposed approach is evaluated in a test case with fifteen missions, thirteen resources and three astronauts. The results show that the developed domain ontology model is reasonable, and the time iteration method using the proposed resolving strategies can successfully obtain the plan satisfying all considered constraints.展开更多
It has long been realized that the problem of radar imaging is a special case of image reconstruction in which the data are incomplete and noisy. In other fields, iterative reconstruction algorithms have been used suc...It has long been realized that the problem of radar imaging is a special case of image reconstruction in which the data are incomplete and noisy. In other fields, iterative reconstruction algorithms have been used successfully to improve the image quality. This paper studies the application of iterative algorithms in radar imaging. A discrete model is first derived, and the iterative algorithms are then adapted to radar imaging. Although such algorithms are usually time consuming, this paper shows that, if the algorithms are appropriately simplified, it is possible to realize them even in real time. The efficiency of iterative algorithms is shown through computer simulations.展开更多
Cone penetration testing (CPT) is a cost effective and popular tool for geotechnical site characterization. CPT consists of pushing at a constant rate an electronic penetrometer into penetrable soils and recording con...Cone penetration testing (CPT) is a cost effective and popular tool for geotechnical site characterization. CPT consists of pushing at a constant rate an electronic penetrometer into penetrable soils and recording cone bearing (q<sub>c</sub>), sleeve friction (f<sub>c</sub>) and dynamic pore pressure (u) with depth. The measured q<sub>c</sub>, f<sub>s</sub> and u values are utilized to estimate soil type and associated soil properties. A popular method to estimate soil type from CPT measurements is the Soil Behavior Type (SBT) chart. The SBT plots cone resistance vs friction ratio, R<sub>f</sub> [where: R<sub>f</sub> = (f<sub>s</sub>/q<sub>c</sub>)100%]. There are distortions in the CPT measurements which can result in erroneous SBT plots. Cone bearing measurements at a specific depth are blurred or averaged due to q<sub>c</sub> values being strongly influenced by soils within 10 to 30 cone diameters from the cone tip. The q<sub>c</sub>HMM algorithm was developed to address the q<sub>c</sub> blurring/averaging limitation. This paper describes the distortions which occur when obtaining sleeve friction measurements which can in association with q<sub>c</sub> blurring result in significant errors in the calculated R<sub>f</sub> values. This paper outlines a novel and highly effective algorithm for obtaining accurate sleeve friction and friction ratio estimates. The f<sub>c</sub> optimal filter estimation technique is referred to as the OSFE-IFM algorithm. The mathematical details of the OSFE-IFM algorithm are outlined in this paper along with the results from a challenging test bed simulation. The test bed simulation demonstrates that the OSFE-IFM algorithm derives accurate estimates of sleeve friction from measured values. Optimal estimates of cone bearing and sleeve friction result in accurate R<sub>f</sub> values and subsequent accurate estimates of soil behavior type.展开更多
Cone penetration testing (CPT) is an extensively utilized and cost effective tool for geotechnical site characterization. CPT consists of pushing at a constant rate an electronic cone into penetrable soils and recordi...Cone penetration testing (CPT) is an extensively utilized and cost effective tool for geotechnical site characterization. CPT consists of pushing at a constant rate an electronic cone into penetrable soils and recording the resistance to the cone tip (q<sub>c</sub> value). The measured q<sub>c</sub> values (after correction for the pore water pressure) are utilized to estimate soil type and associated soil properties based predominantly on empirical correlations. The most common cone tips have associated areas of 10 cm<sup>2</sup> and 15 cm<sup>2</sup>. Investigators also utilized significantly larger cone tips (33 cm<sup>2</sup> and 40 cm<sup>2</sup>) so that gravelly soils can be penetrated. Small cone tips (2 cm<sup>2</sup> and 5 cm<sup>2</sup>) are utilized for shallow soil investigations. The cone tip resistance measured at a particular depth is affected by the values above and below the depth of interest which results in a smoothing or blurring of the true bearing values. Extensive work has been carried out in mathematically modelling the smoothing function which results in the blurred cone bearing measurements. This paper outlines a technique which facilitates estimating the dominant parameters of the cone smoothing function from processing real cone bearing data sets. This cone calibration technique is referred to as the so-called CPSPE algorithm. The mathematical details of the CPSPE algorithm are outlined in this paper along with the results from a challenging test bed simulation.展开更多
By establishing the discrete iterative mapping model of a current mode controlled buck-boost converter, this paper studies the mechanism of mode shift and stability control of the buck-boost converter operating in dis...By establishing the discrete iterative mapping model of a current mode controlled buck-boost converter, this paper studies the mechanism of mode shift and stability control of the buck-boost converter operating in discontinuous conduction mode with a ramp compensation current. With the bifurcation diagrazn, Lyapunov exponent spectrum, time- domain waveform and parameter space map, the performance of the buck-boost converter circuit utilizing a compensating ramp current has been analysed. The obtained results indicate that the system trajectory is weakly chaotic and strongly intermittent under discontinuous conduction mode. By using ramp compensation, the buck-boost converter can shift from discontinuous conduction mode to continuous conduction mode, and effectively operates in the stable period-one region.展开更多
The discrete iterative map model of peak current-mode controlled buck converter with constant current load(CCL),containing the output voltage feedback and ramp compensation, is established in this paper. Based on th...The discrete iterative map model of peak current-mode controlled buck converter with constant current load(CCL),containing the output voltage feedback and ramp compensation, is established in this paper. Based on this model the complex dynamics of this converter is investigated by analyzing bifurcation diagrams and the Lyapunov exponent spectrum. The effects of ramp compensation and output voltage feedback on the stability of the converter are investigated. Experimental results verify the simulation and theoretical analysis. The stability boundary and chaos boundary are obtained under the theoretical conditions of period-doubling bifurcation and border collision. It is found that there are four operation regions in the peak current-mode controlled buck converter with CCL due to period-doubling bifurcation and border-collision bifurcation. Research results indicate that ramp compensation can extend the stable operation range and transfer the operating mode, and output voltage feedback can eventually eliminate the coexisting fast-slow scale instability.展开更多
Decarbonization of the electricity sector is crucial to mitigate the impacts of climate change and global warming over the coming decades.The key challenges for achieving this goal are carbon emission trading and elec...Decarbonization of the electricity sector is crucial to mitigate the impacts of climate change and global warming over the coming decades.The key challenges for achieving this goal are carbon emission trading and electricity sector regulation,which are also the major components of the carbon and electricity markets,respectively.In this paper,a joint electricity and carbon market model is proposed to investigate the relationships between electricity price,carbon price,and electricity generation capacity,thereby identifying pathways toward a renewable energy transition under the transactional energy interconnection framework.The proposed model is a dynamically iterative optimization model consisting of upper-level and lower-level models.The upper-level model optimizes power generation and obtains the electricity price,which drives the lower-level model to update the carbon price and electricity generation capacity.The proposed model is verified using the Northeast Asia power grid.The results show that increasing carbon price will result in increased electricity price,along with further increases in renewable energy generation capacity in the following period.This increase in renewable energy generation will reduce reliance on carbon-emitting energy sources,and hence the carbon price will decline.Moreover,the interconnection among zones in the Northeast Asia power grid will enable reasonable allocation of zonal power generation.Carbon capture and storage (CCS) will be an effective technology to reduce the carbon emissions and further realize the emission reduction targets in 2030-2050.It eases the stress of realizing the energy transition because of the less urgency to install additional renewable energy capacity.展开更多
The discrete iterative map models of peak current-mode (PCM) and valley current-mode (VCM) controlled buck converters, boost converters, and buck-boost converters with ramp compensation are established and their d...The discrete iterative map models of peak current-mode (PCM) and valley current-mode (VCM) controlled buck converters, boost converters, and buck-boost converters with ramp compensation are established and their dynamical behaviours are investigated by using the operation region, parameter space map, bifurcation diagram, and Lyapunov exponent spectrum. The research results indicate that ramp compensation extends the stable operation range of the PCM controlled switching dc-dc converter to D 〉 0.5 and that of the VCM controlled switching dc-dc converter to D 〈 0.5. Compared with PCM controlled switching dc-dc converters with ramp compensation, VCM controlled switching dc-dc converters with ramp compensation exhibit interesting symmetrical dynamics. Experimental results are given to verify the analysis results in this paper.展开更多
In this paper, an iterative learning control algorithm is proposed for discrete linear time-varying systems to track iterationvarying desired trajectories. A high-order internal model(HOIM) is utilized to describe the...In this paper, an iterative learning control algorithm is proposed for discrete linear time-varying systems to track iterationvarying desired trajectories. A high-order internal model(HOIM) is utilized to describe the variation of desired trajectories in the iteration domain. In the sequel, the HOIM is incorporated into the design of learning gains. The learning convergence in the iteration axis can be guaranteed with rigorous proof. The simulation results with permanent magnet linear motors(PMLM) demonstrate that the proposed HOIM based approach yields good performance and achieves perfect tracking.展开更多
Cone penetration testing (CPT) is a widely used geotechnical engineering </span><i><span style="font-family:Verdana;">in-situ</span></i><span style="font-family:Verdana;...Cone penetration testing (CPT) is a widely used geotechnical engineering </span><i><span style="font-family:Verdana;">in-situ</span></i><span style="font-family:Verdana;"> test for mapping soil profiles and assessing soil properties. In CPT, a cone on the end of a series of rods is pushed into the ground at a constant rate and resistance to the cone tip is measured (</span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;">). The </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;"> values are utilized to characterize the soil profile. Unfortunately, the measured cone tip resistance </span></span><span style="font-family:Verdana;">is</span><span style="font-family:""><span style="font-family:Verdana;"> blurred and/or averaged which can result in the distortion of the soil profile characterization and the inability to identify thin layers. This paper outlines a novel and highly effective algorithm for obtaining cone bearing estimates </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub></i><span style="font-family:Verdana;"> from averaged or smoothed </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;"> measurements. This </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub></i><span style="font-family:Verdana;"> optimal filter estimation technique is referred to as the </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub><span style="font-family:Verdana;">HMM-IFM</span></i><span style="font-family:Verdana;"> algorithm and it implements a hybrid hidden Markov model and iterative forward modelling technique. The mathematical details of the </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub><span style="font-family:Verdana;">HMM-IFM</span></i><span style="font-family:Verdana;"> algorithm are outline</span><span style="font-family:Verdana;">d in this paper along with the results from challenging test</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">bed. The test</span><span style="font-family:""> </span><span style="font-family:Verdana;">b</span><span style="font-family:""><span style="font-family:Verdana;">ed simulations have demonstrated that the </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub><span style="font-family:Verdana;">HMM-IFM</span></i><span style="font-family:Verdana;"> algorithm can derive accurate </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub></i><span style="font-family:Verdana;"> values from challenging averaged </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;"> profiles. This allows for greater soil resolution and the identification and quantification of thin layers in a soil profile.展开更多
The paper discusses an extended entropy model for the prediction of trip amount and provides a method to solve it, called the simple block iterative algorithm, from the point of view of the system of nonlinear equatio...The paper discusses an extended entropy model for the prediction of trip amount and provides a method to solve it, called the simple block iterative algorithm, from the point of view of the system of nonlinear equations. Because the algorithm gives consideration to the characteristic of the model, it has better effect in our practice. The paper also studies the existence and uniqueness of the solution and convergence of the algorithm.展开更多
This paper describes an Interactive Modelling and Intelligent Model Management System─IMIMMS.In the system, like-natural English stances can be understood,then they are interpreted into the WFF(Well-Formed Formula) a...This paper describes an Interactive Modelling and Intelligent Model Management System─IMIMMS.In the system, like-natural English stances can be understood,then they are interpreted into the WFF(Well-Formed Formula) as the goals of inference on modelling knowledge.The model is represented as the Predicates and Relational Framework (PRF).The IMIMMS is a problem -oriented system. Therefore, the model frame of solving problem can be generated during the iterative process. The IMIMMS implements intelligent model management and traces the environment change in a decision domain. Finally, the paper shows the IMIMMS framework and an example of iterative modelling.展开更多
In the sense of the nonlinear multisplitting and based on the principle of suffi-ciently using the delayed information, we propose models of asynchronous parallelaccelerated overrelaxation iteration methods for solvin...In the sense of the nonlinear multisplitting and based on the principle of suffi-ciently using the delayed information, we propose models of asynchronous parallelaccelerated overrelaxation iteration methods for solving large scale system of non-linear equations. Under proper conditions, we set up the local convergence theoriesof these new method models.展开更多
文摘Space applications have raised the demand on autonomy, security and reliability for current transportation vehicle, which require guidance technology of vehicle must have strong robustness and adaptability. Therefore, it is needed to research exoatmospheric autonomous iterative guidance method with stronger adaptivity and higher accuracy. Based on preliminary research results, two new iterative models with performance index of maximum terminal energy for exoatmospheric autonomous iterative guidance method are proposed in this paper. Then comparative analysis between preliminary research iterative model and two new iterative models proposed is performed. The results demonstrate that the inner update iterative model proposed is the least sensitive to initial values and have the best convergence and performance in the three iterative models.
基金supported by Korea Institute of Geoscience and Mineral Resources(Project No.GP2017-024)Ministry of Trade and Industry [Project No.NP2017-021(20172510102090)]funded by National Research Foundation of Korea(NRF)Grants(Nos.NRF-2017R1C1B5017767,NRF-2017K2A9A1A01092734)
文摘Most inverse reservoir modeling techniques require many forward simulations, and the posterior models cannot preserve geological features of prior models. This study proposes an iterative static modeling approach that utilizes dynamic data for rejecting an unsuitable training image(TI) among a set of TI candidates and for synthesizing history-matched pseudo-soft data. The proposed method is applied to two cases of channelized reservoirs, which have uncertainty in channel geometry such as direction, amplitude, and width. Distance-based clustering is applied to the initial models in total to select the qualified models efficiently. The mean of the qualified models is employed as a history-matched facies probability map in the next iteration of static models. Also, the most plausible TI is determined among TI candidates by rejecting other TIs during the iteration. The posterior models of the proposed method outperform updated models of ensemble Kalman filter(EnKF) and ensemble smoother(ES) because they describe the true facies connectivity with bimodal distribution and predict oil and water production with a reasonable range of uncertainty. In terms of simulation time, it requires 30 times of forward simulation in history matching, while the EnKF and ES need 9000 times and 200 times, respectively.
基金supported by the National Natural Science Foundation of China(11402295)the Science Project of National University of Defense Technology(JC14-01-05)the Hunan Provincial Natural Science Foundation of China(2015JJ3020)
文摘This paper studies the problem of the space station short-term mission planning, which aims to allocate the executing time of missions effectively, schedule the corresponding resources reasonably and arrange the time of the astronauts properly. A domain model is developed by using the ontology theory to describe the concepts, constraints and relations of the planning domain formally, abstractly and normatively. A method based on time iteration is adopted to solve the short-term planning problem. Meanwhile, the resolving strategies are proposed to resolve different kinds of conflicts induced by the constraints of power, heat, resource, astronaut and relationship. The proposed approach is evaluated in a test case with fifteen missions, thirteen resources and three astronauts. The results show that the developed domain ontology model is reasonable, and the time iteration method using the proposed resolving strategies can successfully obtain the plan satisfying all considered constraints.
文摘It has long been realized that the problem of radar imaging is a special case of image reconstruction in which the data are incomplete and noisy. In other fields, iterative reconstruction algorithms have been used successfully to improve the image quality. This paper studies the application of iterative algorithms in radar imaging. A discrete model is first derived, and the iterative algorithms are then adapted to radar imaging. Although such algorithms are usually time consuming, this paper shows that, if the algorithms are appropriately simplified, it is possible to realize them even in real time. The efficiency of iterative algorithms is shown through computer simulations.
文摘Cone penetration testing (CPT) is a cost effective and popular tool for geotechnical site characterization. CPT consists of pushing at a constant rate an electronic penetrometer into penetrable soils and recording cone bearing (q<sub>c</sub>), sleeve friction (f<sub>c</sub>) and dynamic pore pressure (u) with depth. The measured q<sub>c</sub>, f<sub>s</sub> and u values are utilized to estimate soil type and associated soil properties. A popular method to estimate soil type from CPT measurements is the Soil Behavior Type (SBT) chart. The SBT plots cone resistance vs friction ratio, R<sub>f</sub> [where: R<sub>f</sub> = (f<sub>s</sub>/q<sub>c</sub>)100%]. There are distortions in the CPT measurements which can result in erroneous SBT plots. Cone bearing measurements at a specific depth are blurred or averaged due to q<sub>c</sub> values being strongly influenced by soils within 10 to 30 cone diameters from the cone tip. The q<sub>c</sub>HMM algorithm was developed to address the q<sub>c</sub> blurring/averaging limitation. This paper describes the distortions which occur when obtaining sleeve friction measurements which can in association with q<sub>c</sub> blurring result in significant errors in the calculated R<sub>f</sub> values. This paper outlines a novel and highly effective algorithm for obtaining accurate sleeve friction and friction ratio estimates. The f<sub>c</sub> optimal filter estimation technique is referred to as the OSFE-IFM algorithm. The mathematical details of the OSFE-IFM algorithm are outlined in this paper along with the results from a challenging test bed simulation. The test bed simulation demonstrates that the OSFE-IFM algorithm derives accurate estimates of sleeve friction from measured values. Optimal estimates of cone bearing and sleeve friction result in accurate R<sub>f</sub> values and subsequent accurate estimates of soil behavior type.
文摘Cone penetration testing (CPT) is an extensively utilized and cost effective tool for geotechnical site characterization. CPT consists of pushing at a constant rate an electronic cone into penetrable soils and recording the resistance to the cone tip (q<sub>c</sub> value). The measured q<sub>c</sub> values (after correction for the pore water pressure) are utilized to estimate soil type and associated soil properties based predominantly on empirical correlations. The most common cone tips have associated areas of 10 cm<sup>2</sup> and 15 cm<sup>2</sup>. Investigators also utilized significantly larger cone tips (33 cm<sup>2</sup> and 40 cm<sup>2</sup>) so that gravelly soils can be penetrated. Small cone tips (2 cm<sup>2</sup> and 5 cm<sup>2</sup>) are utilized for shallow soil investigations. The cone tip resistance measured at a particular depth is affected by the values above and below the depth of interest which results in a smoothing or blurring of the true bearing values. Extensive work has been carried out in mathematically modelling the smoothing function which results in the blurred cone bearing measurements. This paper outlines a technique which facilitates estimating the dominant parameters of the cone smoothing function from processing real cone bearing data sets. This cone calibration technique is referred to as the so-called CPSPE algorithm. The mathematical details of the CPSPE algorithm are outlined in this paper along with the results from a challenging test bed simulation.
基金Project supported by the National Natural Science Foundations of China (Grant Nos 50677056 and 60472059)
文摘By establishing the discrete iterative mapping model of a current mode controlled buck-boost converter, this paper studies the mechanism of mode shift and stability control of the buck-boost converter operating in discontinuous conduction mode with a ramp compensation current. With the bifurcation diagrazn, Lyapunov exponent spectrum, time- domain waveform and parameter space map, the performance of the buck-boost converter circuit utilizing a compensating ramp current has been analysed. The obtained results indicate that the system trajectory is weakly chaotic and strongly intermittent under discontinuous conduction mode. By using ramp compensation, the buck-boost converter can shift from discontinuous conduction mode to continuous conduction mode, and effectively operates in the stable period-one region.
基金Project supported by the National Natural Science Foundation of China(Grant No.61371033)the Fok Ying-Tung Education Foundation for Young Teachers in the Higher Education Institutions of China(Grant No.142027)+1 种基金the Sichuan Provincial Youth Science and Technology Fund,China(Grant Nos.2014JQ0015and 2013JQ0033)the Fundamental Research Funds for the Central Universities,China(Grant No.SWJTU11CX029)
文摘The discrete iterative map model of peak current-mode controlled buck converter with constant current load(CCL),containing the output voltage feedback and ramp compensation, is established in this paper. Based on this model the complex dynamics of this converter is investigated by analyzing bifurcation diagrams and the Lyapunov exponent spectrum. The effects of ramp compensation and output voltage feedback on the stability of the converter are investigated. Experimental results verify the simulation and theoretical analysis. The stability boundary and chaos boundary are obtained under the theoretical conditions of period-doubling bifurcation and border collision. It is found that there are four operation regions in the peak current-mode controlled buck converter with CCL due to period-doubling bifurcation and border-collision bifurcation. Research results indicate that ramp compensation can extend the stable operation range and transfer the operating mode, and output voltage feedback can eventually eliminate the coexisting fast-slow scale instability.
基金supported in part by National Key Research and Development Program of China(2016YFB0901900)the Science and Technology Foundation of GEIDCO(SGGEIG00JYJS1900016)
文摘Decarbonization of the electricity sector is crucial to mitigate the impacts of climate change and global warming over the coming decades.The key challenges for achieving this goal are carbon emission trading and electricity sector regulation,which are also the major components of the carbon and electricity markets,respectively.In this paper,a joint electricity and carbon market model is proposed to investigate the relationships between electricity price,carbon price,and electricity generation capacity,thereby identifying pathways toward a renewable energy transition under the transactional energy interconnection framework.The proposed model is a dynamically iterative optimization model consisting of upper-level and lower-level models.The upper-level model optimizes power generation and obtains the electricity price,which drives the lower-level model to update the carbon price and electricity generation capacity.The proposed model is verified using the Northeast Asia power grid.The results show that increasing carbon price will result in increased electricity price,along with further increases in renewable energy generation capacity in the following period.This increase in renewable energy generation will reduce reliance on carbon-emitting energy sources,and hence the carbon price will decline.Moreover,the interconnection among zones in the Northeast Asia power grid will enable reasonable allocation of zonal power generation.Carbon capture and storage (CCS) will be an effective technology to reduce the carbon emissions and further realize the emission reduction targets in 2030-2050.It eases the stress of realizing the energy transition because of the less urgency to install additional renewable energy capacity.
基金Project supported by the National Natural Science Foundation of China (Grant No.50677056)the Natural Science Foundation of Jiangsu Province,China (Grant No.BK2009105)+1 种基金the Cultivation Project of Excellent Doctorate Dissertation of Southwest Jiaotong University,Chinathe Doctoral Innovation Foundation of Southwest Jiaotong University,China
文摘The discrete iterative map models of peak current-mode (PCM) and valley current-mode (VCM) controlled buck converters, boost converters, and buck-boost converters with ramp compensation are established and their dynamical behaviours are investigated by using the operation region, parameter space map, bifurcation diagram, and Lyapunov exponent spectrum. The research results indicate that ramp compensation extends the stable operation range of the PCM controlled switching dc-dc converter to D 〉 0.5 and that of the VCM controlled switching dc-dc converter to D 〈 0.5. Compared with PCM controlled switching dc-dc converters with ramp compensation, VCM controlled switching dc-dc converters with ramp compensation exhibit interesting symmetrical dynamics. Experimental results are given to verify the analysis results in this paper.
基金supported by National Basic Research Program of China(973 Program)(No.2012CB316400)National Natural Science Foundation of China(Nos.61171034 and 61273134)
文摘In this paper, an iterative learning control algorithm is proposed for discrete linear time-varying systems to track iterationvarying desired trajectories. A high-order internal model(HOIM) is utilized to describe the variation of desired trajectories in the iteration domain. In the sequel, the HOIM is incorporated into the design of learning gains. The learning convergence in the iteration axis can be guaranteed with rigorous proof. The simulation results with permanent magnet linear motors(PMLM) demonstrate that the proposed HOIM based approach yields good performance and achieves perfect tracking.
文摘Cone penetration testing (CPT) is a widely used geotechnical engineering </span><i><span style="font-family:Verdana;">in-situ</span></i><span style="font-family:Verdana;"> test for mapping soil profiles and assessing soil properties. In CPT, a cone on the end of a series of rods is pushed into the ground at a constant rate and resistance to the cone tip is measured (</span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;">). The </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;"> values are utilized to characterize the soil profile. Unfortunately, the measured cone tip resistance </span></span><span style="font-family:Verdana;">is</span><span style="font-family:""><span style="font-family:Verdana;"> blurred and/or averaged which can result in the distortion of the soil profile characterization and the inability to identify thin layers. This paper outlines a novel and highly effective algorithm for obtaining cone bearing estimates </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub></i><span style="font-family:Verdana;"> from averaged or smoothed </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;"> measurements. This </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub></i><span style="font-family:Verdana;"> optimal filter estimation technique is referred to as the </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub><span style="font-family:Verdana;">HMM-IFM</span></i><span style="font-family:Verdana;"> algorithm and it implements a hybrid hidden Markov model and iterative forward modelling technique. The mathematical details of the </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub><span style="font-family:Verdana;">HMM-IFM</span></i><span style="font-family:Verdana;"> algorithm are outline</span><span style="font-family:Verdana;">d in this paper along with the results from challenging test</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">bed. The test</span><span style="font-family:""> </span><span style="font-family:Verdana;">b</span><span style="font-family:""><span style="font-family:Verdana;">ed simulations have demonstrated that the </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub><span style="font-family:Verdana;">HMM-IFM</span></i><span style="font-family:Verdana;"> algorithm can derive accurate </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">t</span></sub></i><span style="font-family:Verdana;"> values from challenging averaged </span><i><span style="font-family:Verdana;">q</span><sub><span style="font-family:Verdana;">m</span></sub></i><span style="font-family:Verdana;"> profiles. This allows for greater soil resolution and the identification and quantification of thin layers in a soil profile.
文摘The paper discusses an extended entropy model for the prediction of trip amount and provides a method to solve it, called the simple block iterative algorithm, from the point of view of the system of nonlinear equations. Because the algorithm gives consideration to the characteristic of the model, it has better effect in our practice. The paper also studies the existence and uniqueness of the solution and convergence of the algorithm.
文摘This paper describes an Interactive Modelling and Intelligent Model Management System─IMIMMS.In the system, like-natural English stances can be understood,then they are interpreted into the WFF(Well-Formed Formula) as the goals of inference on modelling knowledge.The model is represented as the Predicates and Relational Framework (PRF).The IMIMMS is a problem -oriented system. Therefore, the model frame of solving problem can be generated during the iterative process. The IMIMMS implements intelligent model management and traces the environment change in a decision domain. Finally, the paper shows the IMIMMS framework and an example of iterative modelling.
文摘In the sense of the nonlinear multisplitting and based on the principle of suffi-ciently using the delayed information, we propose models of asynchronous parallelaccelerated overrelaxation iteration methods for solving large scale system of non-linear equations. Under proper conditions, we set up the local convergence theoriesof these new method models.