This paper introduces a multi-granularity locking model (MGL) for concurrency control in object-oriented database system briefiy, and presents a MGL model formally. Four lockingscheduling algorithms for MGL are propos...This paper introduces a multi-granularity locking model (MGL) for concurrency control in object-oriented database system briefiy, and presents a MGL model formally. Four lockingscheduling algorithms for MGL are proposed in the paper. The ideas of single queue scheduling(SQS) and dual queue scheduling (DQS) are proposed and the algorithm and the performance evaluation for these two scheduling are presented in some paper. This paper describes a new idea of thescheduling for MGL, compatible requests first (CRF). Combining the new idea with SQS and DQS,we propose two new scheduling algorithms called CRFS and CRFD. After describing the simulationmodel, this paper illustrates the comparisons of the performance among these four algorithms. Asshown in the experiments, DQS has better performance than SQS, CRFD is better than DQS, CRFSperforms better than SQS, and CRFS is the best one of these four scheduling algorithms.展开更多
Rehabilitation engineering aims in the upmost degree to restore the lost functions for those persons with physical disability. Biomechanical modeling has been widely used for different purposes in rehabilitation engin...Rehabilitation engineering aims in the upmost degree to restore the lost functions for those persons with physical disability. Biomechanical modeling has been widely used for different purposes in rehabilitation engineering to understand the bio-展开更多
The exploration of stable and highly efficient alkaline hydrogen evolution reaction(HER)electrocatalysts is imperative for alkaline water splitting.Herein,Se-doped NiCoP with hierarchical nanoarray structures directly...The exploration of stable and highly efficient alkaline hydrogen evolution reaction(HER)electrocatalysts is imperative for alkaline water splitting.Herein,Se-doped NiCoP with hierarchical nanoarray structures directly grown on carbon cloth(Se-NiCoP/CC)was prepared by hydrothermal reaction and phosphorization/selenization process.The experimental results reveal that Se doping could increase the electrochemical active sites and alter the electronic structure of NiCoP.The optimized Se-NiCoP/CC electrode exhibits outstanding HER activity in alkaline electrolyte,which only needs a low overpotential of 79 mV at the current density of 10 mA/cm^(2).When serving as anode and cathode electrode simultaneously,the Se-NiCoP/CC electrodes achieve current density of 50 mA/cm^(2) at a low voltage of only 1.62 V.This work provides a feasible way to rationally design high active HER electrocatalysts.展开更多
This paper describes a new method of small moving target detection and analyzes the performance of this algorithm. The method is based on multi-level threshold decision-making and sliding trajectory confidence testing...This paper describes a new method of small moving target detection and analyzes the performance of this algorithm. The method is based on multi-level threshold decision-making and sliding trajectory confidence testing technology. The parameters of the algorithm are also given. Experiments have been conducted, the results show that the algorithm has advantages of high detection probability, simple structure, and excellent real-time performance.展开更多
The problem of identification of friend-or-foe aircraft in the actual application condition is addressed.A hybrid algorithm combining fuzzy neutral network with probability factor（FNNP）,multi-level fuzzy comprehensi...The problem of identification of friend-or-foe aircraft in the actual application condition is addressed.A hybrid algorithm combining fuzzy neutral network with probability factor（FNNP）,multi-level fuzzy comprehensive evaluation and the DempsterShafer（D-S） theory is proposed.This hybrid algorithm constructs a complete process from generating the fuzzy database to the final identification,realizes the identification of friend-or-foe automatically if the training samples or expert’s experience can be obtained,and reduces the effect of uncertainties in the process of identification.At the same time,the whole algorithm can update the identification result with the augment of observations.The performance of the proposed algorithm is assessed by simulations.Results show that the proposed algorithm can successfully deduce the aircraft’s identity even if the observations have measurement errors.展开更多
Multi-level inverters(MLIs)have become popular in different applications such as industrial power control systems and distributed generations.There are different forms of MLIs.The cascaded MLIs(CMLIs)have some special...Multi-level inverters(MLIs)have become popular in different applications such as industrial power control systems and distributed generations.There are different forms of MLIs.The cascaded MLIs(CMLIs)have some special advantages among them such as more different output voltage levels using the same number of components and higher power quality.In this paper,a 27-level inverter switching algorithm considering total harmonic distortion(THD)minimization is investigated.Switching angles of the inverter switches are achieved by minimizing a THD-based objective function.In order to minimize the THD-based objective function,the hyper-spherical search(HSS)algorithm,as a novel optimization algorithm,is improved and the results of improved HSS(IHSS)are compared with HSS algorithm and other five evolutionary algorithms to show the advantages of IHSS algorithm.展开更多
Grid-connected current control is one.of the important control schemes in distributed generation systems.A lot of control methods have been developed,such as hysteresis control,dead-beat control,one-cycle control,etc....Grid-connected current control is one.of the important control schemes in distributed generation systems.A lot of control methods have been developed,such as hysteresis control,dead-beat control,one-cycle control,etc.Hysteresis current control has the advantages of simplicity,robustness and good large-signal response.Unfortunately,the switching frequency of the converter using hysteresis current control varies according to the parameters of the bus voltage,the filter inductor and the bandwidth.Increasing the hysteresis bandwidth and the filter inductance can reduce the switching frequency.展开更多
文摘This paper introduces a multi-granularity locking model (MGL) for concurrency control in object-oriented database system briefiy, and presents a MGL model formally. Four lockingscheduling algorithms for MGL are proposed in the paper. The ideas of single queue scheduling(SQS) and dual queue scheduling (DQS) are proposed and the algorithm and the performance evaluation for these two scheduling are presented in some paper. This paper describes a new idea of thescheduling for MGL, compatible requests first (CRF). Combining the new idea with SQS and DQS,we propose two new scheduling algorithms called CRFS and CRFD. After describing the simulationmodel, this paper illustrates the comparisons of the performance among these four algorithms. Asshown in the experiments, DQS has better performance than SQS, CRFD is better than DQS, CRFSperforms better than SQS, and CRFS is the best one of these four scheduling algorithms.
基金Research Grant Council of Hong Kong (GRF Project nos PolyU5331 /07E,PolyU5352 /08E)a grant from Ministry of Sciences and Technology,China (No 2006BAI22B00)
文摘Rehabilitation engineering aims in the upmost degree to restore the lost functions for those persons with physical disability. Biomechanical modeling has been widely used for different purposes in rehabilitation engineering to understand the bio-
基金Projects(51772086,51872087,51971089)supported by the National Natural Science Foundation of ChinaProject(2018TP1037-202102)supported by Open Fund of Hunan Provincial Key Laboratory of Advanced Materials for New Energy Storage and Conversion,China+1 种基金Project supported by Student National SIT Innovation Program,ChinaProject(2020CB1007)supported by Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy,China。
文摘The exploration of stable and highly efficient alkaline hydrogen evolution reaction(HER)electrocatalysts is imperative for alkaline water splitting.Herein,Se-doped NiCoP with hierarchical nanoarray structures directly grown on carbon cloth(Se-NiCoP/CC)was prepared by hydrothermal reaction and phosphorization/selenization process.The experimental results reveal that Se doping could increase the electrochemical active sites and alter the electronic structure of NiCoP.The optimized Se-NiCoP/CC electrode exhibits outstanding HER activity in alkaline electrolyte,which only needs a low overpotential of 79 mV at the current density of 10 mA/cm^(2).When serving as anode and cathode electrode simultaneously,the Se-NiCoP/CC electrodes achieve current density of 50 mA/cm^(2) at a low voltage of only 1.62 V.This work provides a feasible way to rationally design high active HER electrocatalysts.
文摘This paper describes a new method of small moving target detection and analyzes the performance of this algorithm. The method is based on multi-level threshold decision-making and sliding trajectory confidence testing technology. The parameters of the algorithm are also given. Experiments have been conducted, the results show that the algorithm has advantages of high detection probability, simple structure, and excellent real-time performance.
文摘The problem of identification of friend-or-foe aircraft in the actual application condition is addressed.A hybrid algorithm combining fuzzy neutral network with probability factor（FNNP）,multi-level fuzzy comprehensive evaluation and the DempsterShafer（D-S） theory is proposed.This hybrid algorithm constructs a complete process from generating the fuzzy database to the final identification,realizes the identification of friend-or-foe automatically if the training samples or expert’s experience can be obtained,and reduces the effect of uncertainties in the process of identification.At the same time,the whole algorithm can update the identification result with the augment of observations.The performance of the proposed algorithm is assessed by simulations.Results show that the proposed algorithm can successfully deduce the aircraft’s identity even if the observations have measurement errors.
文摘Multi-level inverters(MLIs)have become popular in different applications such as industrial power control systems and distributed generations.There are different forms of MLIs.The cascaded MLIs(CMLIs)have some special advantages among them such as more different output voltage levels using the same number of components and higher power quality.In this paper,a 27-level inverter switching algorithm considering total harmonic distortion(THD)minimization is investigated.Switching angles of the inverter switches are achieved by minimizing a THD-based objective function.In order to minimize the THD-based objective function,the hyper-spherical search(HSS)algorithm,as a novel optimization algorithm,is improved and the results of improved HSS(IHSS)are compared with HSS algorithm and other five evolutionary algorithms to show the advantages of IHSS algorithm.
文摘Grid-connected current control is one.of the important control schemes in distributed generation systems.A lot of control methods have been developed,such as hysteresis control,dead-beat control,one-cycle control,etc.Hysteresis current control has the advantages of simplicity,robustness and good large-signal response.Unfortunately,the switching frequency of the converter using hysteresis current control varies according to the parameters of the bus voltage,the filter inductor and the bandwidth.Increasing the hysteresis bandwidth and the filter inductance can reduce the switching frequency.
