The electricity-hydrogen integrated energy system(EH-IES)enables synergistic operation of electricity,heat,and hydrogen subsystems,supporting renewable energy integration and efficient multi-energy utilization in futu...The electricity-hydrogen integrated energy system(EH-IES)enables synergistic operation of electricity,heat,and hydrogen subsystems,supporting renewable energy integration and efficient multi-energy utilization in future low carbon societies.However,uncertainties from renewable energy and load variability threaten system safety and economy.Conventional chance-constrained programming(CCP)ensures reliable operation by limiting risk.However,increasing source-load uncertainties that can render CCP models infeasible and exacerbate operational risks.To address this,this paper proposes a risk-adjustable chance-constrained goal programming(RACCGP)model,integrating CCP and goal programming to balance risk and cost based on system risk assessment.An intelligent nonlinear goal programming method based on the state transition algorithm(STA)is developed,along with an improved discretized step transformation,to handle model nonlinearity and enhance computational efficiency.Experimental results show that the proposed model reduces costs while controlling risk compared to traditional CCP,and the solution method outperforms average sample sampling in efficiency and solution quality.展开更多
In this paper,a bandwidth-adjustable extended state observer(ABESO)is proposed for the systems with measurement noise.It is known that increasing the bandwidth of the observer improves the tracking speed but tolerates...In this paper,a bandwidth-adjustable extended state observer(ABESO)is proposed for the systems with measurement noise.It is known that increasing the bandwidth of the observer improves the tracking speed but tolerates noise,which conflicts with observation accuracy.Therefore,we introduce a bandwidth scaling factor such that ABESO is formulated to a 2-degree-of-freedom system.The observer gain is determined and the bandwidth scaling factor adjusts the bandwidth according to the tracking error.When the tracking error decreases,the bandwidth decreases to suppress the noise,otherwise the bandwidth does not change.It is proven that the error dynamics are bounded and converge in finite time.The relationship between the upper bound of the estimation error and the scaling factor is given.When the scaling factor is less than 1,the ABESO has higher estimation accuracy than the linear extended state observer(LESO).Simulations of an uncertain nonlinear system with compound disturbances show that the proposed ABESO can successfully estimate the total disturbance in noisy environments.The mean error of total disturbance of ABESO is 15.28% lower than that of LESO.展开更多
The increasingly complex battlefield environment requests much closer connection in a team having both manned and unmanned aerial vehicles(MAVs and UAVs). This special heterogeneous team structure causes demands for e...The increasingly complex battlefield environment requests much closer connection in a team having both manned and unmanned aerial vehicles(MAVs and UAVs). This special heterogeneous team structure causes demands for effective organizational structure design solutions. Implementing adjustable autonomy in the organizational structure, the expected evaluation function is established based on the physical resource, intelligent resource, network efficiency, network vulnerability and task execution reliability. According to the above constraints, together with interaction latency, decision-making information processing capacity, and decision-making latency, we aim to find a preferential organizational structure. The proposed organizational structure includes cooperative relationships, supervisory control relationships, and decision-making authorization relationships. In addition,by considering the influence on the intelligent support capabilities and the task execution reliability created by adjustable autonomy, it helps to build the proposed organizational structure designed with certain degree of flexibility to deal with the potential changes in the unpredictable battlefield environment. Simulation is conducted to confirm our design to be valid. And the method is still valid under different battlefield environments and interventions.展开更多
Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduli...Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.展开更多
Based on KKT complementary condition in optimization theory, an unconstrained non-differential optimization model for support vector machine is proposed. An adjustable entropy function method is given to deal with the...Based on KKT complementary condition in optimization theory, an unconstrained non-differential optimization model for support vector machine is proposed. An adjustable entropy function method is given to deal with the proposed optimization problem and the Newton algorithm is used to figure out the optimal solution. The proposed method can find an optimal solution with a relatively small parameter p, which avoids the numerical overflow in the traditional entropy function methods. It is a new approach to solve support vector machine. The theoretical analysis and experimental results illustrate the feasibility and efficiency of the proposed algorithm.展开更多
In a system based on the phase lock loop（PLL）, a trade-off must be made between the tracking precision and the dynamic performance if constant parameters are adopted. To overcome this drawback, a new method called n...In a system based on the phase lock loop（PLL）, a trade-off must be made between the tracking precision and the dynamic performance if constant parameters are adopted. To overcome this drawback, a new method called no phase slipping adaptive bandwidth（NPS-AB） is proposed, which can adjust the loop bandwidth adaptively for different working conditions. As a result, both the tracking precision and the dynamic performance can be achieved concurrently. NPS-AB has two features to keep the loop stable： one is the capability of quick response to dynamics; the other is a series of additional constraints when the bandwidth is switched. Compared with other methods, there is no phase slipping during the adjustment process for NPS-AB. The phase integer ambiguity can be avoided and the phase value is kept valid. It is meaningful for carrier ranging systems. Simulation results show that NPS-AB can deal with sudden dynamics and keep the pseudo-range value stable in the entire dynamic process.展开更多
DEA is a nonparametric method used in operation researches and economics fields for the evaluation of the production frontier. It has distinct intrinsic which is worth coping with assessment problems with multiple inp...DEA is a nonparametric method used in operation researches and economics fields for the evaluation of the production frontier. It has distinct intrinsic which is worth coping with assessment problems with multiple inputs in particular with multiple outputs. This paper used D~ C2 R model of DEA to assess the comparative efficiency of the multiple schemes of agricultural industrial structure, at the end we chose the most favorable also known as ＂OPTIMAL＂ scheme. In addition to this, using some functional insights from DEA model non optimal schemes or less optimal schemes had also been improved to some extent. Assessment and selection of optimal schemes of agricultural industrial structure using DEA model gave a greater and better insight of agricultural industrial structure and was the first of such researches in Pakistan.展开更多
DEA is a new research field in operations research. It has unique virtues in dealing with assessment problem with multi-inputs especially multi-outputs. In this paper, DEA model of D?着C2R has been applied to evaluate...DEA is a new research field in operations research. It has unique virtues in dealing with assessment problem with multi-inputs especially multi-outputs. In this paper, DEA model of D?着C2R has been applied to evaluate the relative efficiency of several different schemes of industrial structure adjustment of agriculture and finally select the optimal scheme. Furthermore, the inferior scheme has been improved according to some useful insights got from DEA model.展开更多
A new kind of optimal fuzzy PID controller is proposed, which contains two parts. One is an on line fuzzy inference system, and the other is a conventional PID controller. In the fuzzy inference system, three adjustab...A new kind of optimal fuzzy PID controller is proposed, which contains two parts. One is an on line fuzzy inference system, and the other is a conventional PID controller. In the fuzzy inference system, three adjustable factors x p, x i , and x d are introduced. Their functions are to further modify and optimize the result of the fuzzy inference so as to make the controller have the optimal control effect on a given object. The optimal values of these adjustable factors are determined based on the ITAE criterion and the Nelder and Mead′s flexible polyhedron search algorithm. This optimal fuzzy PID controller has been used to control the executive motor of the intelligent artificial leg designed by the authors. The result of computer simulation indicates that this controller is very effective and can be widely used to control different kinds of objects and processes.展开更多
This paper used the modern evaluation method of DEA （Data Envelopment Analysis） to assess the comparative efficiency and then on the basis of this among multiple schemes chose the optimal scheme of agricultural prod...This paper used the modern evaluation method of DEA （Data Envelopment Analysis） to assess the comparative efficiency and then on the basis of this among multiple schemes chose the optimal scheme of agricultural production structure adjustment. Based on the results of DEA model, we dissected scale advantages of each discretionary scheme or plan. We examined scale advantages of each discretionary scheme, tested profoundly a definitive purpose behind not-DEA efficient, which elucidated the system and methodology to enhance these discretionary plans. At the end, another method had been proposed to rank and select the optimal scheme. The research was important to guide the practice if the modification of agricultural production industrial structure was carded on.展开更多
in the paper, the advanced assessment method of DEA （Date Envelopment Analysis） had been used to evaluate relative efficiency and select the optimal scheme of agricultural industrial structure adjustment. According ...in the paper, the advanced assessment method of DEA （Date Envelopment Analysis） had been used to evaluate relative efficiency and select the optimal scheme of agricultural industrial structure adjustment. According to the results of DEA models, we analyzed scale benefits of every optional schemes, probed deeply the ultimate reason for not DEA efficient, which clarified the method and approach to improve these optional schemes. Finally, a new method had been proposed to rank and select the optimal scheme. The research is significant to direct the practice of the adjustment of agricultural industrial structure.展开更多
A hierarchical scheme of feature-based model similarity measurement was proposed,named CSG_D2,in which both geometry similarity and topology similarity were applied.The features of 3D mechanical part were constructed ...A hierarchical scheme of feature-based model similarity measurement was proposed,named CSG_D2,in which both geometry similarity and topology similarity were applied.The features of 3D mechanical part were constructed by a series of primitive features with tree structure,as a form of constructive solid geometry(CSG) tree.The D2 shape distributions of these features were extracted for geometry similarity measurement,and the pose vector and non-disappeared proportion of each leaf node were gained for topology similarity measurement.Based on these,the dissimilarity between the query and the candidate was accessed by level-by-level CSG tree comparisons.With the adjustable weights,our scheme satisfies different comparison emphasis on the geometry or topology similarity.The assessment results from CSG_D2 demonstrate more discriminative than those from D2 in the analysis of precision-recall and similarity matrix.Finally,an experimental search engine is applied for mechanical parts reuse by using CSG_D2,which is convenient for the mechanical design process.展开更多
Aimed at the abominable influences to blind equaliza-tion algorithms caused by complex time-space variability existing in underwater acoustic channels, a new self-adjusting decision feedback equalization （DFE） algor...Aimed at the abominable influences to blind equaliza-tion algorithms caused by complex time-space variability existing in underwater acoustic channels, a new self-adjusting decision feedback equalization （DFE） algorithm adapting to different under-water acoustic channel environments is proposed by changing its central tap position. Besides, this new algorithm behaves faster convergence speed based on the analysis of equalizers’ working rules, which is more suitable to implement communications in dif-ferent unknown channels. Corresponding results and conclusions are validated by simulations and spot experiments.展开更多
Aiming at a comprehensive assessment of energy-saving retrofitting effect on existing buildings,a calculation method is developed to adjust energy-saving quantity in standard condition for comparison under the same co...Aiming at a comprehensive assessment of energy-saving retrofitting effect on existing buildings,a calculation method is developed to adjust energy-saving quantity in standard condition for comparison under the same conditions. A mathematical model,method theory and calculation steps are given. Error analysis results show that this method can be applied accurately to practical engineering projects. In a case study of energy-saving quantity assessment before and after retrofitting on a certain hospital in Shanghai,with energy simulation software TRNSYS,detailed application of this method is introduced and analyzed. The method is applied to the case of energy-saving quantity assessment to a hospital in Shanghai before and after retrofitting with the energy simulation software TRNSYS.展开更多
To simulate the different lunar phases and ensure continuous adjustability of the radiant brightness,a new broad spectrum light and frosted glass were applied and designed in the optical system for lunar simulator wit...To simulate the different lunar phases and ensure continuous adjustability of the radiant brightness,a new broad spectrum light and frosted glass were applied and designed in the optical system for lunar simulator with the shapes and radiance being able to be adjusted.According to the engineering demand and index requirements of the optical system,three major design aspects are addressed,including the high reliability and maintainability for broad-spectrum light,heat dissipation in lunar simulator for long working hours,and bearing of the main frame under different working conditions.By designing a reasonable machine structure,and through the structure itself with the matrix arrangement of 48 axial flow fans,an effectively cooling air duct is established.Deformation and temperature were calculated by the finite element software ANSYS.The results showed that the displacement deformation reached 0.33 mm and stress deformation reached 0.02 MPa at the temperature of 20℃;when the main frame was in the temperature field between 20℃ and65℃,the maximum displacement deformation reached 13.30 mm and maximum stress deformation is 97.90 MPa,and the amount of this deformation is very small in considering of the mechanical structure dimensions and weight of the lunar simulator.展开更多
Two varieties of winter wheat,Bei Nong 2(B. N. 2)and Jing 411(J. 411),were selected for osmotic adjustment study. At wheat growing stages,from recovery period to mature period,leaf relative water content(LRWC) ,water ...Two varieties of winter wheat,Bei Nong 2(B. N. 2)and Jing 411(J. 411),were selected for osmotic adjustment study. At wheat growing stages,from recovery period to mature period,leaf relative water content(LRWC) ,water potential(LWP)and saturated osmotic potential (LSOP) were positively correlated to soil relative water content (SRWC) and decreased as SRWC descended at each growth stage,and the decreasing range exhibited B. N. 2【J. 411. The turgor pressure(TP)of both the varieties decreased less than LRWC and LWP. It was shown that both varieties had a osmotic adjustment ability(OAA) ,and the decreasing range presented B. N. 2【J. 411. Both the varieties had a TP tubercle in TP vs SRWC graph at heading and filling stages,and their OAA was the strongest at these two stages.展开更多
The distribution of velocity is one of the basic issues in river dynamics.Based on the experimental data measured by ADV in the flume of State Key Hydraulics Laboratory (SKHL),this paper analyzed the ver- tical distri...The distribution of velocity is one of the basic issues in river dynamics.Based on the experimental data measured by ADV in the flume of State Key Hydraulics Laboratory (SKHL),this paper analyzed the ver- tical distribution of point velocity and the varying law of turbulence intensity in straight mobile compound chan- nel with an asymmetric floodplain.Above certain relative height,the streamwise point velocity follows the loga- rithmic distribution.Below the location,the velocity varies linearly approxim...展开更多
To solve the inequality problem, an adjustable entropy method is proposed. An inequality problem can be transformed into a minimax problem which is nondifferentiable; then an adjustable entropy is used to smooth the m...To solve the inequality problem, an adjustable entropy method is proposed. An inequality problem can be transformed into a minimax problem which is nondifferentiable; then an adjustable entropy is used to smooth the minimax problem. The solution of inequalities can be approached by using a BFGS algorithm of the standard optimization method. Some properties of the new approximate function are presented and then the global convergence are given according to the algorithm. Two numerical examples illustrate that the proposed method is efficient and is superior to the former ones.展开更多
By considering economic strength and economic profit of insurance company, this paper presents a concept-contact point, and gives premium expectation adjust-time model which provides more practical significance for in...By considering economic strength and economic profit of insurance company, this paper presents a concept-contact point, and gives premium expectation adjust-time model which provides more practical significance for insurance company to make rational adjustment of premium. Finally, an illustration is given to show their application.展开更多
基金Project(2022YFC2904502)supported by the National Key Research and Development Program of ChinaProject(62273357)supported by the National Natural Science Foundation of China。
文摘The electricity-hydrogen integrated energy system(EH-IES)enables synergistic operation of electricity,heat,and hydrogen subsystems,supporting renewable energy integration and efficient multi-energy utilization in future low carbon societies.However,uncertainties from renewable energy and load variability threaten system safety and economy.Conventional chance-constrained programming(CCP)ensures reliable operation by limiting risk.However,increasing source-load uncertainties that can render CCP models infeasible and exacerbate operational risks.To address this,this paper proposes a risk-adjustable chance-constrained goal programming(RACCGP)model,integrating CCP and goal programming to balance risk and cost based on system risk assessment.An intelligent nonlinear goal programming method based on the state transition algorithm(STA)is developed,along with an improved discretized step transformation,to handle model nonlinearity and enhance computational efficiency.Experimental results show that the proposed model reduces costs while controlling risk compared to traditional CCP,and the solution method outperforms average sample sampling in efficiency and solution quality.
基金supported by the National Natural Science Foundation of China(61873126)。
文摘In this paper,a bandwidth-adjustable extended state observer(ABESO)is proposed for the systems with measurement noise.It is known that increasing the bandwidth of the observer improves the tracking speed but tolerates noise,which conflicts with observation accuracy.Therefore,we introduce a bandwidth scaling factor such that ABESO is formulated to a 2-degree-of-freedom system.The observer gain is determined and the bandwidth scaling factor adjusts the bandwidth according to the tracking error.When the tracking error decreases,the bandwidth decreases to suppress the noise,otherwise the bandwidth does not change.It is proven that the error dynamics are bounded and converge in finite time.The relationship between the upper bound of the estimation error and the scaling factor is given.When the scaling factor is less than 1,the ABESO has higher estimation accuracy than the linear extended state observer(LESO).Simulations of an uncertain nonlinear system with compound disturbances show that the proposed ABESO can successfully estimate the total disturbance in noisy environments.The mean error of total disturbance of ABESO is 15.28% lower than that of LESO.
基金supported by the National Natural Science Foundation of China(61305133)the Aeronautical Science Foundation of China(2016ZC53020)the Fundamental Research Funds for the Central Universities(3102017jg02015)
文摘The increasingly complex battlefield environment requests much closer connection in a team having both manned and unmanned aerial vehicles(MAVs and UAVs). This special heterogeneous team structure causes demands for effective organizational structure design solutions. Implementing adjustable autonomy in the organizational structure, the expected evaluation function is established based on the physical resource, intelligent resource, network efficiency, network vulnerability and task execution reliability. According to the above constraints, together with interaction latency, decision-making information processing capacity, and decision-making latency, we aim to find a preferential organizational structure. The proposed organizational structure includes cooperative relationships, supervisory control relationships, and decision-making authorization relationships. In addition,by considering the influence on the intelligent support capabilities and the task execution reliability created by adjustable autonomy, it helps to build the proposed organizational structure designed with certain degree of flexibility to deal with the potential changes in the unpredictable battlefield environment. Simulation is conducted to confirm our design to be valid. And the method is still valid under different battlefield environments and interventions.
基金supported by the National Natural Science Foundation of China(6113200291338101+3 种基金91338108)the National S&T Major Project(2011ZX03004-001-01)the Research Fund of Tsinghua University(2011Z05117)the Co-innovation Laboratory of Aerospace Broadband Network Technology
文摘Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.
基金the National Natural Science Foundation of China (60574075)
文摘Based on KKT complementary condition in optimization theory, an unconstrained non-differential optimization model for support vector machine is proposed. An adjustable entropy function method is given to deal with the proposed optimization problem and the Newton algorithm is used to figure out the optimal solution. The proposed method can find an optimal solution with a relatively small parameter p, which avoids the numerical overflow in the traditional entropy function methods. It is a new approach to solve support vector machine. The theoretical analysis and experimental results illustrate the feasibility and efficiency of the proposed algorithm.
文摘In a system based on the phase lock loop（PLL）, a trade-off must be made between the tracking precision and the dynamic performance if constant parameters are adopted. To overcome this drawback, a new method called no phase slipping adaptive bandwidth（NPS-AB） is proposed, which can adjust the loop bandwidth adaptively for different working conditions. As a result, both the tracking precision and the dynamic performance can be achieved concurrently. NPS-AB has two features to keep the loop stable： one is the capability of quick response to dynamics; the other is a series of additional constraints when the bandwidth is switched. Compared with other methods, there is no phase slipping during the adjustment process for NPS-AB. The phase integer ambiguity can be avoided and the phase value is kept valid. It is meaningful for carrier ranging systems. Simulation results show that NPS-AB can deal with sudden dynamics and keep the pseudo-range value stable in the entire dynamic process.
文摘DEA is a nonparametric method used in operation researches and economics fields for the evaluation of the production frontier. It has distinct intrinsic which is worth coping with assessment problems with multiple inputs in particular with multiple outputs. This paper used D~ C2 R model of DEA to assess the comparative efficiency of the multiple schemes of agricultural industrial structure, at the end we chose the most favorable also known as ＂OPTIMAL＂ scheme. In addition to this, using some functional insights from DEA model non optimal schemes or less optimal schemes had also been improved to some extent. Assessment and selection of optimal schemes of agricultural industrial structure using DEA model gave a greater and better insight of agricultural industrial structure and was the first of such researches in Pakistan.
文摘DEA is a new research field in operations research. It has unique virtues in dealing with assessment problem with multi-inputs especially multi-outputs. In this paper, DEA model of D?着C2R has been applied to evaluate the relative efficiency of several different schemes of industrial structure adjustment of agriculture and finally select the optimal scheme. Furthermore, the inferior scheme has been improved according to some useful insights got from DEA model.
文摘A new kind of optimal fuzzy PID controller is proposed, which contains two parts. One is an on line fuzzy inference system, and the other is a conventional PID controller. In the fuzzy inference system, three adjustable factors x p, x i , and x d are introduced. Their functions are to further modify and optimize the result of the fuzzy inference so as to make the controller have the optimal control effect on a given object. The optimal values of these adjustable factors are determined based on the ITAE criterion and the Nelder and Mead′s flexible polyhedron search algorithm. This optimal fuzzy PID controller has been used to control the executive motor of the intelligent artificial leg designed by the authors. The result of computer simulation indicates that this controller is very effective and can be widely used to control different kinds of objects and processes.
文摘This paper used the modern evaluation method of DEA （Data Envelopment Analysis） to assess the comparative efficiency and then on the basis of this among multiple schemes chose the optimal scheme of agricultural production structure adjustment. Based on the results of DEA model, we dissected scale advantages of each discretionary scheme or plan. We examined scale advantages of each discretionary scheme, tested profoundly a definitive purpose behind not-DEA efficient, which elucidated the system and methodology to enhance these discretionary plans. At the end, another method had been proposed to rank and select the optimal scheme. The research was important to guide the practice if the modification of agricultural production industrial structure was carded on.
基金National Science and Technology Programming (Research and Paradigm of Persisting and High Efficiency Agriculture 2001-DA508-D09-4)
文摘in the paper, the advanced assessment method of DEA （Date Envelopment Analysis） had been used to evaluate relative efficiency and select the optimal scheme of agricultural industrial structure adjustment. According to the results of DEA models, we analyzed scale benefits of every optional schemes, probed deeply the ultimate reason for not DEA efficient, which clarified the method and approach to improve these optional schemes. Finally, a new method had been proposed to rank and select the optimal scheme. The research is significant to direct the practice of the adjustment of agricultural industrial structure.
基金Project(51175287)supported by the National Natural Science Foundation of ChinaProject(2006AA04Z112)supported by National High Technology Research and Development Program of China
文摘A hierarchical scheme of feature-based model similarity measurement was proposed,named CSG_D2,in which both geometry similarity and topology similarity were applied.The features of 3D mechanical part were constructed by a series of primitive features with tree structure,as a form of constructive solid geometry(CSG) tree.The D2 shape distributions of these features were extracted for geometry similarity measurement,and the pose vector and non-disappeared proportion of each leaf node were gained for topology similarity measurement.Based on these,the dissimilarity between the query and the candidate was accessed by level-by-level CSG tree comparisons.With the adjustable weights,our scheme satisfies different comparison emphasis on the geometry or topology similarity.The assessment results from CSG_D2 demonstrate more discriminative than those from D2 in the analysis of precision-recall and similarity matrix.Finally,an experimental search engine is applied for mechanical parts reuse by using CSG_D2,which is convenient for the mechanical design process.
基金supported by the National Natural Science Foundation of China(61101205)the Natural Science Foundation of Hubei Province of China(2009CDB337)the Natural Science Foundation of Naval University of Engineering(HGDQNJJ13019)
文摘Aimed at the abominable influences to blind equaliza-tion algorithms caused by complex time-space variability existing in underwater acoustic channels, a new self-adjusting decision feedback equalization （DFE） algorithm adapting to different under-water acoustic channel environments is proposed by changing its central tap position. Besides, this new algorithm behaves faster convergence speed based on the analysis of equalizers’ working rules, which is more suitable to implement communications in dif-ferent unknown channels. Corresponding results and conclusions are validated by simulations and spot experiments.
基金Project(2006BAJ03A10) supported by the National Key Technologies R & D Program of China
文摘Aiming at a comprehensive assessment of energy-saving retrofitting effect on existing buildings,a calculation method is developed to adjust energy-saving quantity in standard condition for comparison under the same conditions. A mathematical model,method theory and calculation steps are given. Error analysis results show that this method can be applied accurately to practical engineering projects. In a case study of energy-saving quantity assessment before and after retrofitting on a certain hospital in Shanghai,with energy simulation software TRNSYS,detailed application of this method is introduced and analyzed. The method is applied to the case of energy-saving quantity assessment to a hospital in Shanghai before and after retrofitting with the energy simulation software TRNSYS.
基金Supported by National Public Welfare Industry(GYHY200706003,GYHY201006043)
文摘To simulate the different lunar phases and ensure continuous adjustability of the radiant brightness,a new broad spectrum light and frosted glass were applied and designed in the optical system for lunar simulator with the shapes and radiance being able to be adjusted.According to the engineering demand and index requirements of the optical system,three major design aspects are addressed,including the high reliability and maintainability for broad-spectrum light,heat dissipation in lunar simulator for long working hours,and bearing of the main frame under different working conditions.By designing a reasonable machine structure,and through the structure itself with the matrix arrangement of 48 axial flow fans,an effectively cooling air duct is established.Deformation and temperature were calculated by the finite element software ANSYS.The results showed that the displacement deformation reached 0.33 mm and stress deformation reached 0.02 MPa at the temperature of 20℃;when the main frame was in the temperature field between 20℃ and65℃,the maximum displacement deformation reached 13.30 mm and maximum stress deformation is 97.90 MPa,and the amount of this deformation is very small in considering of the mechanical structure dimensions and weight of the lunar simulator.
文摘Two varieties of winter wheat,Bei Nong 2(B. N. 2)and Jing 411(J. 411),were selected for osmotic adjustment study. At wheat growing stages,from recovery period to mature period,leaf relative water content(LRWC) ,water potential(LWP)and saturated osmotic potential (LSOP) were positively correlated to soil relative water content (SRWC) and decreased as SRWC descended at each growth stage,and the decreasing range exhibited B. N. 2【J. 411. The turgor pressure(TP)of both the varieties decreased less than LRWC and LWP. It was shown that both varieties had a osmotic adjustment ability(OAA) ,and the decreasing range presented B. N. 2【J. 411. Both the varieties had a TP tubercle in TP vs SRWC graph at heading and filling stages,and their OAA was the strongest at these two stages.
基金Supported by Key Project of Chinese.Ministry of Education (03134)
文摘The distribution of velocity is one of the basic issues in river dynamics.Based on the experimental data measured by ADV in the flume of State Key Hydraulics Laboratory (SKHL),this paper analyzed the ver- tical distribution of point velocity and the varying law of turbulence intensity in straight mobile compound chan- nel with an asymmetric floodplain.Above certain relative height,the streamwise point velocity follows the loga- rithmic distribution.Below the location,the velocity varies linearly approxim...
文摘To solve the inequality problem, an adjustable entropy method is proposed. An inequality problem can be transformed into a minimax problem which is nondifferentiable; then an adjustable entropy is used to smooth the minimax problem. The solution of inequalities can be approached by using a BFGS algorithm of the standard optimization method. Some properties of the new approximate function are presented and then the global convergence are given according to the algorithm. Two numerical examples illustrate that the proposed method is efficient and is superior to the former ones.
文摘By considering economic strength and economic profit of insurance company, this paper presents a concept-contact point, and gives premium expectation adjust-time model which provides more practical significance for insurance company to make rational adjustment of premium. Finally, an illustration is given to show their application.
