The post-Newtonian scheme in multiple systems with post-Newtonian parameters presented by Klioner and Soffel is extended to the post-post-Newtonian (PPN) order for light propagation problem in the solar system. Unde...The post-Newtonian scheme in multiple systems with post-Newtonian parameters presented by Klioner and Soffel is extended to the post-post-Newtonian (PPN) order for light propagation problem in the solar system. Under considering the solar system experiment requirement, a new parameter ε is introduced. This extension does not change the virtue of the scheme on the linear partial differential equations of the potential and vector potential mentioned in previous work. Furthermore, this extension is based on the former work done by Richter and Matzner in one global system theory. As an application, we also consider the deflection of light ray in the global coordinates. And the deflection angle of light ray is obtained with post-Newtonian parameters.展开更多
The problem of stabilizing a class of large-scale non-linear multiple delay systems is considered.The complicated system is decomposed into several subsystems; each function of them is expressed by a set of components...The problem of stabilizing a class of large-scale non-linear multiple delay systems is considered.The complicated system is decomposed into several subsystems; each function of them is expressed by a set of components of the overall state vector,with interconnections between them, and the subsystems are coupled by the delayed state. In this paper, a method is devised to be a suitable choice of state feedback controls of every subsystems, moreover, it is proved that the large-scale system is exponential stable.展开更多
In an integrated refining and petrochemical complex,a centralized utility system(CUS)is introduced to integrate the steam demands of production plants.Besides,two sub-utility systems(SUSs)located inside the alkene and...In an integrated refining and petrochemical complex,a centralized utility system(CUS)is introduced to integrate the steam demands of production plants.Besides,two sub-utility systems(SUSs)located inside the alkene and refinery plants,respectively,can satisfy the shaft demands.It is difficult to determine the steam production of the CUS because the steam demands of the alkene and refinery plants also depend on the design and operation of the SUSs.To explore the complicated interaction between the CUS and SUSs,we proposed a mixed-integer nonlinear programming(MINLP)model for the design and optimization of multiple interconnected utility systems to minimize the total annualized cost(TAC).An extended superstructure was suggested to contain multiple inter-plant connected steam pipe alternatives between the CUS and SUSs.A more accurate model of the complex steam turbine was proposed.Then the proposed MINLP framework is applied to a new integrated refining and petrochemical complex.Two scenarios are investigated in the case study to explore the effect of steam main temperatures on system configurations and operating parameters.By optimizing the main temperatures,a TAC of$2.7 million can be saved.Judging from the results of the two scenarios,the feasibility and effectiveness of the proposed framework for the design and optimization of multiple interconnected utility systems have been demonstrated.展开更多
The seed method is used for solving multiple linear systems A (i)x (i) =b (i) for 1≤i≤s, where the coefficient matrix A (i) and the right-hand side b (i) are different in general. It is known that the CG meth...The seed method is used for solving multiple linear systems A (i)x (i) =b (i) for 1≤i≤s, where the coefficient matrix A (i) and the right-hand side b (i) are different in general. It is known that the CG method is an effective method for symmetric coefficient matrices A (i). In this paper, the FOM method is employed to solve multiple linear sy stems when coefficient matrices are non-symmetric matrices. One of the systems is selected as the seed system which generates a Krylov subspace, then the resi duals of other systems are projected onto the generated Krylov subspace to get t he approximate solutions for the unsolved ones. The whole process is repeated u ntil all the systems are solved.展开更多
The characteristic that multiple limb manipulation systems can resist disturbance external forces without relying on the feedback control of joint torques, called the robustness, has been addressed by several resear...The characteristic that multiple limb manipulation systems can resist disturbance external forces without relying on the feedback control of joint torques, called the robustness, has been addressed by several researchers. Based on their results, a further study of robustness is presented in this paper. By decomposing the space of external forces into two subspaces, the necessary and sufficient condition for a system to have robustness is given and a definition of robustness which is applicable to any multiple limb systems is also proposed. For the purpose of the evaluation of robustness, a new quality measure — critical disturbance external force and its algorithm are put forward. Finally, two examples of robustness analysis are presented.展开更多
I. Introduction In this paper we are looking for solutions of the following Hamiltonian system of second order: where x= (x1, x2) and V satisfies (V. 1) V: R×R2→R is a C1-function, 1-periodic In t, (V.2) V...I. Introduction In this paper we are looking for solutions of the following Hamiltonian system of second order: where x= (x1, x2) and V satisfies (V. 1) V: R×R2→R is a C1-function, 1-periodic In t, (V.2) V is periodic in x1 with the period T>0, (V. 3) V→O, Vx→O as |x2|→∞, uniformly in (t, x1).展开更多
Previous analytical results on flow splitting are generalized to consider multiple boiling channels systems. The analysis is consistent with the approximations usually adopted in the use of systems codes (like RELAP5 ...Previous analytical results on flow splitting are generalized to consider multiple boiling channels systems. The analysis is consistent with the approximations usually adopted in the use of systems codes (like RELAP5 and TRACE5, among others) commonly applied to perform safety analyses of nuclear power plants. The problem is related to multiple, identical, parallel boiling channels, connected through common plena. A theoretical model limited in scope explains this flow splitting without reversal. The unified analysis performed and the confirmatory computational results found are summarized in this paper. New maps showing the zones where this behavior is predicted are also shown considering again twin pipes. Multiple pipe systems have been found not easily amenable for analytical analysis when dealing with more than four parallel pipes. However, the particular splitting found (flow along N pipes dividing in one standalone pipe flow plus N -1 identical pipe flows) has been verified up to fourteen pipes, involving calculations in systems with even and odd number of pipes using the RELAP5 systems thermal-hydraulics code.展开更多
Background: Mycobacterium avium complex (MAC) infection case which involves bones and joints are rare scenarios. Here, we report a rare case of Penicillium marneffei (PM), lung infection and systemic multi joint damag...Background: Mycobacterium avium complex (MAC) infection case which involves bones and joints are rare scenarios. Here, we report a rare case of Penicillium marneffei (PM), lung infection and systemic multi joint damage reported with positive anti-interferon-gamma at the same time. Case Presentation: A 55-year-old woman with fever for 10 days due to repeated multiple joint pain for more than one month was admitted to our hospital on September 19th 2020. During hospitalization, the patient was confirmed with mycobacterium avium combined with Penicillium marneffei (PM) infection involving multiple bone joints. Antifungal therapy and immunity regulatory agent were given during hospitalization. Following pharmocol-therapy, symptoms gradually improved, and the patient was discharged. Conclusions: The patient was considered disseminated and refractory non-tubercular mycobacterium (NTM) combined with Penicillium marneffei infection. In addition, we found that anti IFN-γ autoantibodies are closely related. Although the current incidence of this patient is related to anti IFN-γ, there is a strong correlation between autoantibody-mediated immunodeficiency in adults.展开更多
BACKGROUND Pulmonary Langerhans cell histiocytosis(PLCH)is a relatively rare type of lung disease,common in middle-aged smoking men.It is characterized by proliferation and infiltration of Langerhans cells,and the for...BACKGROUND Pulmonary Langerhans cell histiocytosis(PLCH)is a relatively rare type of lung disease,common in middle-aged smoking men.It is characterized by proliferation and infiltration of Langerhans cells,and the formation of multiple parabronchial mesenchymal nodules in lung tissue,and may lead to organ dysfunction.There are no typical symptoms and signs,and it is easily misdiagnosed or missed,and therefore deserves clinical attention and further discussion.CASE SUMMARY We describe the case of a nonsmoking 46-year-old man with PLCH diagnosed based on clinical manifestations of fever and dry cough,with a history of hypothyroidism and diabetes insipidus for 9 years.Computed tomography(CT)-and CT-guided puncture examinations revealed no abnormalities,and he ultimately underwent thoracoscopic biopsy to confirm the diagnosis.The pathological diagnosis was PLCH.Thyroid function was maintained by medication.Pituitary magnetic resonance imaging showed that the pituitary stalk had become thinner.CONCLUSION LCH often involves multiple systems.Moreover,the pathogenesis is not clear,clinical manifestations lack specificity,and diagnosis requires special attention.Diagnosis of PLCH can significantly benefit from comprehensive multidisciplinary analysis.展开更多
The strategies that minimize the overall solution time of multiple linear systems in 3D finite element method (FEM) modeling of direct current (DC) resistivity were discussed. A global stiff matrix is assembled and st...The strategies that minimize the overall solution time of multiple linear systems in 3D finite element method (FEM) modeling of direct current (DC) resistivity were discussed. A global stiff matrix is assembled and stored in two parts separately. One part is associated with the volume integral and the other is associated with the subsurface boundary integral. The equivalent multiple linear systems with closer right-hand sides than the original systems were constructed. A recycling Krylov subspace technique was employed to solve the multiple linear systems. The solution of the seed system was used as an initial guess for the subsequent systems. The results of two numerical experiments show that the improved algorithm reduces the iterations and CPU time by almost 50%, compared with the classical preconditioned conjugate gradient method.展开更多
A higher-order cumulant-based weighted least square(HOCWLS) and a higher-order cumulant-based iterative least square(HOCILS) are derived for multiple inputs single output(MISO) errors-in-variables(EIV) systems...A higher-order cumulant-based weighted least square(HOCWLS) and a higher-order cumulant-based iterative least square(HOCILS) are derived for multiple inputs single output(MISO) errors-in-variables(EIV) systems from noisy input/output data. Whether the noises of the input/output of the system are white or colored, the proposed algorithms can be insensitive to these noises and yield unbiased estimates. To realize adaptive parameter estimates, a higher-order cumulant-based recursive least square(HOCRLS) method is also studied. Convergence analysis of the HOCRLS is conducted by using the stochastic process theory and the stochastic martingale theory. It indicates that the parameter estimation error of HOCRLS consistently converges to zero under a generalized persistent excitation condition. The usefulness of the proposed algorithms is assessed through numerical simulations.展开更多
Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multipl...Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.展开更多
A lattice reduction aided (LRA) minimum mean square error (MMSE) Tomlinson-Harashima pre-coding (THP) was proposed based on vertical Bell Labs layered space time (VBLAST) algorithm for multiple input multiple output (...A lattice reduction aided (LRA) minimum mean square error (MMSE) Tomlinson-Harashima pre-coding (THP) was proposed based on vertical Bell Labs layered space time (VBLAST) algorithm for multiple input multiple output (MIMO) systems. The extended channel was used to provide optimal tradeoff between residual interference and noise amplification. The processing based on lattice reduction method helps achieve maximal diversity order. The VBLAST algorithm was applied to get the optimal processing ordering for successive interference cancellation (SIC) at transmitter. Simulation results show that the proposed algorithm outperforms conventional THP and the LRA zero-forcing (ZF) THP with full diversity order.展开更多
The complexity of the indoor environment brings great challenges to predict the electromagnetic radiation field of multiple antenna systems. Based on the Finite Difference Time Domain (FDTD) algorithm, using the mobil...The complexity of the indoor environment brings great challenges to predict the electromagnetic radiation field of multiple antenna systems. Based on the Finite Difference Time Domain (FDTD) algorithm, using the mobile phone shielding device as the multiple antenna systems example, the mobile phone shielding device's indoor electromagnetic radiation field is researched by measurment method and simulation method. The effectivity of prediction method is verified by comparing the prediciton results with the measurment results. About 80% of the error can be controlled less than dB. The quantitative research has certain guiding significance to the prediction of the multiple antenna systems radio wave propagation.展开更多
In this paper we introduce the concept of tensor sum semigroups. Also we have given the examples of tensor sum operators which induce dynamical system on weighted locally convex function spaces.
Background:China has achieved universal health insurance coverage.This study examined how patients and hospitals react to the different designs of the plans and to monitoring of patients by the local authority in the...Background:China has achieved universal health insurance coverage.This study examined how patients and hospitals react to the different designs of the plans and to monitoring of patients by the local authority in the Chinese multiple health security schemes.Methods:The sample for analysis consisted of 1006 orthopedic inpatients who were admitted between January and December 2011 at a tertiary teaching hospital located in Beijing.We conducted general linear regression analyses to investigate whether medical expenditure and length of stay differed according to the different incentives.Results:Patients under plans with lower copayment rates consumed significantly more medication compared with those under plans with higher copayment rates.Under plans with an annual ceiling for insurance coverage,patients spent significantly more in the second half of the year than in the first half of the year.The length of stay was shorter among patients when there were government monitoring and a penalty to the hospital service provider.Conclusions:Our results indicate that the different designs and monitoring of the health security systems in China cause opportunistic behavior by patients and providers.Reformation is necessary to reduce those incentives,and improve equity and efficiency in healthcare use.展开更多
From 1986 to 1991,based on AMSAA model, ZHOU Yuan_quan and WENG Zhao_xi presented AMSAA_BISE model to estimate reliability growth for multiple systems development, for the case that more than one system of the same ty...From 1986 to 1991,based on AMSAA model, ZHOU Yuan_quan and WENG Zhao_xi presented AMSAA_BISE model to estimate reliability growth for multiple systems development, for the case that more than one system of the same type is put into reliability growth test, once a Type B failure mode is seen during test, corrective action will be taken to all systems. It is shown that there is something wrong with AMSAA_BISE model. According to AMSAA_BISE model, the maximum likelihood estimation of MTBF for multiple systems reliability growth test is much larger than that according to AMSAA model for a single system; The more systems is put into test, the larger the estimation of MTBF. An example is given, and an approximate method is presented.展开更多
As an integrated carrier of energy production,transmission,distribution,conversion,storage,and utilization,multiple energy systems(MESs)have significant low-carbon potential.This paper proposes a hierarchical distribu...As an integrated carrier of energy production,transmission,distribution,conversion,storage,and utilization,multiple energy systems(MESs)have significant low-carbon potential.This paper proposes a hierarchical distributed dispatch model of MESs considering carbon trading,which is composed of the lower autonomous operation level of each MES and the upper coordinated control level.Different carbon emission sources are considered,including combined heat and power(CHP)units,gas boilers,and power to gas(P2G)devices.The transactive control(TC)mechanism is used to solve the model by introducing a virtual price signal.In the case study based on a 3-MES system,the effectiveness of the proposed distributed method is proved by comparison with a centralized algorithm.Meanwhile,the impacts of different carbon prices on MESs with different resource endowments are analyzed from the aspects of scheduling results,carbon emissions,clean energy consumption rate,and comprehensive operating costs.展开更多
Integrating a battery energy storage system(ESS)with a large wind farm can smooth the intermittent power obtained from the wind farm,but the smoothing function will not be achieved if multiple ESSs are used to smooth ...Integrating a battery energy storage system(ESS)with a large wind farm can smooth the intermittent power obtained from the wind farm,but the smoothing function will not be achieved if multiple ESSs are used to smooth the fluctuations in individual wind power plants in a distributed pattern.Therefore,this study focuses on the development of a control strategy to optimize the use of multiple ESSs to accelerate the adoption of wind energy resources.This paper proposes a quasi-automated generation control(QAGC)strategy to coordinate multiple ESSs,which responds to the grid dispatch demand rather than smoothing out the intermittent power from individual wind farms.The aims of QAGC are to ensure that multiple ESSs provide a service that is as balanced as possible,so more wind power systems at various scales can be accepted by the grid,as well maximizing the low-carbon benefits of ESSs.The effectiveness of QAGC is demonstrated by using data from an actual gigawatt scale cluster of wind plants.展开更多
The sufficient conditions of delay-dependent exponential stability for switched systems and robust exponential stability for uncertain switched systems with two time-delays are presented by using average dwell time me...The sufficient conditions of delay-dependent exponential stability for switched systems and robust exponential stability for uncertain switched systems with two time-delays are presented by using average dwell time method and free-weighting matrix method.The interaction between different time-delays is considered.The sufficient conditions do not need that every subsystem is stable.The designed methods of the switching law are also given.The sufficient conditions are given in the form of linear matrix inequalities that can be solved easily.The result is proven to be valid by the simulation at last.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 10674099)the National Science Foundation for Young Scientists of China (Grant No. 10925313)the Shandong Provincial Natural Science Foundation,China (GrantNo. ZR2010AQ023)
文摘The post-Newtonian scheme in multiple systems with post-Newtonian parameters presented by Klioner and Soffel is extended to the post-post-Newtonian (PPN) order for light propagation problem in the solar system. Under considering the solar system experiment requirement, a new parameter ε is introduced. This extension does not change the virtue of the scheme on the linear partial differential equations of the potential and vector potential mentioned in previous work. Furthermore, this extension is based on the former work done by Richter and Matzner in one global system theory. As an application, we also consider the deflection of light ray in the global coordinates. And the deflection angle of light ray is obtained with post-Newtonian parameters.
文摘The problem of stabilizing a class of large-scale non-linear multiple delay systems is considered.The complicated system is decomposed into several subsystems; each function of them is expressed by a set of components of the overall state vector,with interconnections between them, and the subsystems are coupled by the delayed state. In this paper, a method is devised to be a suitable choice of state feedback controls of every subsystems, moreover, it is proved that the large-scale system is exponential stable.
文摘In an integrated refining and petrochemical complex,a centralized utility system(CUS)is introduced to integrate the steam demands of production plants.Besides,two sub-utility systems(SUSs)located inside the alkene and refinery plants,respectively,can satisfy the shaft demands.It is difficult to determine the steam production of the CUS because the steam demands of the alkene and refinery plants also depend on the design and operation of the SUSs.To explore the complicated interaction between the CUS and SUSs,we proposed a mixed-integer nonlinear programming(MINLP)model for the design and optimization of multiple interconnected utility systems to minimize the total annualized cost(TAC).An extended superstructure was suggested to contain multiple inter-plant connected steam pipe alternatives between the CUS and SUSs.A more accurate model of the complex steam turbine was proposed.Then the proposed MINLP framework is applied to a new integrated refining and petrochemical complex.Two scenarios are investigated in the case study to explore the effect of steam main temperatures on system configurations and operating parameters.By optimizing the main temperatures,a TAC of$2.7 million can be saved.Judging from the results of the two scenarios,the feasibility and effectiveness of the proposed framework for the design and optimization of multiple interconnected utility systems have been demonstrated.
基金Project supported by the National Natural Science Foundation of China (Grant No.10271075)
文摘The seed method is used for solving multiple linear systems A (i)x (i) =b (i) for 1≤i≤s, where the coefficient matrix A (i) and the right-hand side b (i) are different in general. It is known that the CG method is an effective method for symmetric coefficient matrices A (i). In this paper, the FOM method is employed to solve multiple linear sy stems when coefficient matrices are non-symmetric matrices. One of the systems is selected as the seed system which generates a Krylov subspace, then the resi duals of other systems are projected onto the generated Krylov subspace to get t he approximate solutions for the unsolved ones. The whole process is repeated u ntil all the systems are solved.
文摘The characteristic that multiple limb manipulation systems can resist disturbance external forces without relying on the feedback control of joint torques, called the robustness, has been addressed by several researchers. Based on their results, a further study of robustness is presented in this paper. By decomposing the space of external forces into two subspaces, the necessary and sufficient condition for a system to have robustness is given and a definition of robustness which is applicable to any multiple limb systems is also proposed. For the purpose of the evaluation of robustness, a new quality measure — critical disturbance external force and its algorithm are put forward. Finally, two examples of robustness analysis are presented.
文摘I. Introduction In this paper we are looking for solutions of the following Hamiltonian system of second order: where x= (x1, x2) and V satisfies (V. 1) V: R×R2→R is a C1-function, 1-periodic In t, (V.2) V is periodic in x1 with the period T>0, (V. 3) V→O, Vx→O as |x2|→∞, uniformly in (t, x1).
文摘Previous analytical results on flow splitting are generalized to consider multiple boiling channels systems. The analysis is consistent with the approximations usually adopted in the use of systems codes (like RELAP5 and TRACE5, among others) commonly applied to perform safety analyses of nuclear power plants. The problem is related to multiple, identical, parallel boiling channels, connected through common plena. A theoretical model limited in scope explains this flow splitting without reversal. The unified analysis performed and the confirmatory computational results found are summarized in this paper. New maps showing the zones where this behavior is predicted are also shown considering again twin pipes. Multiple pipe systems have been found not easily amenable for analytical analysis when dealing with more than four parallel pipes. However, the particular splitting found (flow along N pipes dividing in one standalone pipe flow plus N -1 identical pipe flows) has been verified up to fourteen pipes, involving calculations in systems with even and odd number of pipes using the RELAP5 systems thermal-hydraulics code.
文摘Background: Mycobacterium avium complex (MAC) infection case which involves bones and joints are rare scenarios. Here, we report a rare case of Penicillium marneffei (PM), lung infection and systemic multi joint damage reported with positive anti-interferon-gamma at the same time. Case Presentation: A 55-year-old woman with fever for 10 days due to repeated multiple joint pain for more than one month was admitted to our hospital on September 19th 2020. During hospitalization, the patient was confirmed with mycobacterium avium combined with Penicillium marneffei (PM) infection involving multiple bone joints. Antifungal therapy and immunity regulatory agent were given during hospitalization. Following pharmocol-therapy, symptoms gradually improved, and the patient was discharged. Conclusions: The patient was considered disseminated and refractory non-tubercular mycobacterium (NTM) combined with Penicillium marneffei infection. In addition, we found that anti IFN-γ autoantibodies are closely related. Although the current incidence of this patient is related to anti IFN-γ, there is a strong correlation between autoantibody-mediated immunodeficiency in adults.
文摘BACKGROUND Pulmonary Langerhans cell histiocytosis(PLCH)is a relatively rare type of lung disease,common in middle-aged smoking men.It is characterized by proliferation and infiltration of Langerhans cells,and the formation of multiple parabronchial mesenchymal nodules in lung tissue,and may lead to organ dysfunction.There are no typical symptoms and signs,and it is easily misdiagnosed or missed,and therefore deserves clinical attention and further discussion.CASE SUMMARY We describe the case of a nonsmoking 46-year-old man with PLCH diagnosed based on clinical manifestations of fever and dry cough,with a history of hypothyroidism and diabetes insipidus for 9 years.Computed tomography(CT)-and CT-guided puncture examinations revealed no abnormalities,and he ultimately underwent thoracoscopic biopsy to confirm the diagnosis.The pathological diagnosis was PLCH.Thyroid function was maintained by medication.Pituitary magnetic resonance imaging showed that the pituitary stalk had become thinner.CONCLUSION LCH often involves multiple systems.Moreover,the pathogenesis is not clear,clinical manifestations lack specificity,and diagnosis requires special attention.Diagnosis of PLCH can significantly benefit from comprehensive multidisciplinary analysis.
基金Projects(40974077,41164004)supported by the National Natural Science Foundation of ChinaProject(2007AA06Z134)supported by the National High Technology Research and Development Program of China+2 种基金Projects(2011GXNSFA018003,0832263)supported by the Natural Science Foundation of Guangxi Province,ChinaProject supported by Program for Excellent Talents in Guangxi Higher Education Institution,ChinaProject supported by the Foundation of Guilin University of Technology,China
文摘The strategies that minimize the overall solution time of multiple linear systems in 3D finite element method (FEM) modeling of direct current (DC) resistivity were discussed. A global stiff matrix is assembled and stored in two parts separately. One part is associated with the volume integral and the other is associated with the subsurface boundary integral. The equivalent multiple linear systems with closer right-hand sides than the original systems were constructed. A recycling Krylov subspace technique was employed to solve the multiple linear systems. The solution of the seed system was used as an initial guess for the subsequent systems. The results of two numerical experiments show that the improved algorithm reduces the iterations and CPU time by almost 50%, compared with the classical preconditioned conjugate gradient method.
基金supported by the National High Technology Researchand Development Program of China(863 Program)(2012AA121602)the Preliminary Research Program of the General Armament Department of China(51322050202)
文摘A higher-order cumulant-based weighted least square(HOCWLS) and a higher-order cumulant-based iterative least square(HOCILS) are derived for multiple inputs single output(MISO) errors-in-variables(EIV) systems from noisy input/output data. Whether the noises of the input/output of the system are white or colored, the proposed algorithms can be insensitive to these noises and yield unbiased estimates. To realize adaptive parameter estimates, a higher-order cumulant-based recursive least square(HOCRLS) method is also studied. Convergence analysis of the HOCRLS is conducted by using the stochastic process theory and the stochastic martingale theory. It indicates that the parameter estimation error of HOCRLS consistently converges to zero under a generalized persistent excitation condition. The usefulness of the proposed algorithms is assessed through numerical simulations.
文摘Digital Communications, in relation to wireless networks, have taken off in recent years due to the expanding need to communicate faster and more efficiently. A popular way to achieve this is by using wireless Multiple Input Multiple Output (MIMO) communication systems. MIMO systems utilize Space Time Block Codes (STBC) as one of the leading ways to obtain higher data rates with limited bandwidth and power. With several STBC methods currently available, this paper analyzes simulations using Orthogonal Space Time Block Codes (OSTBC) in Rayleigh fading channels to evaluate the performance of MIMO systems. The selection to use a Rayleigh fading channel as a model for a non-line-of-sight (nLOS) environment is selected to mimic installations where a large number of signal paths and reflections are expected. All simulations are coded, generated and plotted using MATLAB resulting in graphical data representing the bit-error rate (BER) to signal-to-noise ratio (Eb/N<sub>0</sub>) or SNR. Each simulation captures how different configurations of key variables including code rate, diversity and antenna count can impact system performance. Four modulation schemes (BPSK, QPSK, 16-QAM and 64-QAM) are included in each simulation. Conclusive evidence based upon these simulations suggests higher diversity gains were achieved with a greater number of antennas. The most significant factor for increasing system performance was using a lower count of transmit antennas with a higher count of receive antennas.
基金The National Natural Science Foundation of China (No. 60772100) The Science and Technology Committee of Shanghai (No. 060215013)
文摘A lattice reduction aided (LRA) minimum mean square error (MMSE) Tomlinson-Harashima pre-coding (THP) was proposed based on vertical Bell Labs layered space time (VBLAST) algorithm for multiple input multiple output (MIMO) systems. The extended channel was used to provide optimal tradeoff between residual interference and noise amplification. The processing based on lattice reduction method helps achieve maximal diversity order. The VBLAST algorithm was applied to get the optimal processing ordering for successive interference cancellation (SIC) at transmitter. Simulation results show that the proposed algorithm outperforms conventional THP and the LRA zero-forcing (ZF) THP with full diversity order.
基金Supported by the State Environmental Protection Commonweal Industry Research Special of China (No.200909106)
文摘The complexity of the indoor environment brings great challenges to predict the electromagnetic radiation field of multiple antenna systems. Based on the Finite Difference Time Domain (FDTD) algorithm, using the mobile phone shielding device as the multiple antenna systems example, the mobile phone shielding device's indoor electromagnetic radiation field is researched by measurment method and simulation method. The effectivity of prediction method is verified by comparing the prediciton results with the measurment results. About 80% of the error can be controlled less than dB. The quantitative research has certain guiding significance to the prediction of the multiple antenna systems radio wave propagation.
文摘In this paper we introduce the concept of tensor sum semigroups. Also we have given the examples of tensor sum operators which induce dynamical system on weighted locally convex function spaces.
文摘Background:China has achieved universal health insurance coverage.This study examined how patients and hospitals react to the different designs of the plans and to monitoring of patients by the local authority in the Chinese multiple health security schemes.Methods:The sample for analysis consisted of 1006 orthopedic inpatients who were admitted between January and December 2011 at a tertiary teaching hospital located in Beijing.We conducted general linear regression analyses to investigate whether medical expenditure and length of stay differed according to the different incentives.Results:Patients under plans with lower copayment rates consumed significantly more medication compared with those under plans with higher copayment rates.Under plans with an annual ceiling for insurance coverage,patients spent significantly more in the second half of the year than in the first half of the year.The length of stay was shorter among patients when there were government monitoring and a penalty to the hospital service provider.Conclusions:Our results indicate that the different designs and monitoring of the health security systems in China cause opportunistic behavior by patients and providers.Reformation is necessary to reduce those incentives,and improve equity and efficiency in healthcare use.
文摘From 1986 to 1991,based on AMSAA model, ZHOU Yuan_quan and WENG Zhao_xi presented AMSAA_BISE model to estimate reliability growth for multiple systems development, for the case that more than one system of the same type is put into reliability growth test, once a Type B failure mode is seen during test, corrective action will be taken to all systems. It is shown that there is something wrong with AMSAA_BISE model. According to AMSAA_BISE model, the maximum likelihood estimation of MTBF for multiple systems reliability growth test is much larger than that according to AMSAA model for a single system; The more systems is put into test, the larger the estimation of MTBF. An example is given, and an approximate method is presented.
基金supported by the National Natural Science Foundation of China (U2166211).
文摘As an integrated carrier of energy production,transmission,distribution,conversion,storage,and utilization,multiple energy systems(MESs)have significant low-carbon potential.This paper proposes a hierarchical distributed dispatch model of MESs considering carbon trading,which is composed of the lower autonomous operation level of each MES and the upper coordinated control level.Different carbon emission sources are considered,including combined heat and power(CHP)units,gas boilers,and power to gas(P2G)devices.The transactive control(TC)mechanism is used to solve the model by introducing a virtual price signal.In the case study based on a 3-MES system,the effectiveness of the proposed distributed method is proved by comparison with a centralized algorithm.Meanwhile,the impacts of different carbon prices on MESs with different resource endowments are analyzed from the aspects of scheduling results,carbon emissions,clean energy consumption rate,and comprehensive operating costs.
基金This work is supported by National Basic Research Program of China(973 Program)(No.2013CB228201).
文摘Integrating a battery energy storage system(ESS)with a large wind farm can smooth the intermittent power obtained from the wind farm,but the smoothing function will not be achieved if multiple ESSs are used to smooth the fluctuations in individual wind power plants in a distributed pattern.Therefore,this study focuses on the development of a control strategy to optimize the use of multiple ESSs to accelerate the adoption of wind energy resources.This paper proposes a quasi-automated generation control(QAGC)strategy to coordinate multiple ESSs,which responds to the grid dispatch demand rather than smoothing out the intermittent power from individual wind farms.The aims of QAGC are to ensure that multiple ESSs provide a service that is as balanced as possible,so more wind power systems at various scales can be accepted by the grid,as well maximizing the low-carbon benefits of ESSs.The effectiveness of QAGC is demonstrated by using data from an actual gigawatt scale cluster of wind plants.
基金supported by the Program of 211 Innovation Engieering on Information in Xiamen University (2009-2011) the Aeronautical Science Foundation of China (No. 2009ZH68022)
文摘The sufficient conditions of delay-dependent exponential stability for switched systems and robust exponential stability for uncertain switched systems with two time-delays are presented by using average dwell time method and free-weighting matrix method.The interaction between different time-delays is considered.The sufficient conditions do not need that every subsystem is stable.The designed methods of the switching law are also given.The sufficient conditions are given in the form of linear matrix inequalities that can be solved easily.The result is proven to be valid by the simulation at last.