The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing paramet...The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.展开更多
In light of the shortcomings in soil compaction observed in ridge cultivation following seeding in Northeast China,it was deemed necessary to develop a solution that would address the issue of soil moisture conservati...In light of the shortcomings in soil compaction observed in ridge cultivation following seeding in Northeast China,it was deemed necessary to develop a solution that would address the issue of soil moisture conservation and temperature control on the seedbed.The slide vibrational compaction device(SVPD),which is capable of compacting the upper and lateral soil of the ridge,was thus designed.The device features adjustable parameters,including an upper compacting plate inlet width of 260-360 mm,an outlet width of 230-290 mm,and a side compacting plate width of 140-240 mm.Its key components include an eccentric block generating vibratory force,a spring system with adjustable stiffness for controlled compaction,and compacting plates designed for uniform soil coverage.The optimal working parameters were determined to be an eccentric block angle of 36.00°,spring stiffness of 46.00 N/mm,and an upper plate exit width of 284.00 mm.The device achieves soil bulk densities of 1.206 g/cm^(3)on the ridge and 1.148 g/cm^(3)on the ridge side,significantly improving compaction compared to traditional methods,and increasing maize yield by 5%.Therefore,in order to meet the agronomic requirements of soil bulk density for crop growth on the ridge,the sliding vibration compacting device also achieves effective compaction of the soil on the ridge side,providing effective technical support for crop emergence and growth under the monoculture planting pattern in Northeastern China.展开更多
This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet （AS J） cutting process and construct its cutting model. Orthogonal test ...This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet （AS J） cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerr ratio of the bottom width to the top width can be determined. In addition, the analysis of ranges and variances are all employed to identify various factors： traverse rate, working pressure, nozzle diameter, standoff distance which denote the importance order of the cutting parameters affecting cutting depth and the kerf ratio of the bottom width to the top width. ~rthermore, non-linear regression analysis is used to establish the mathematical models of the cutting parameters based on the cutting depth and the kerr ratio. Finally, the verification experiments of cutting parameters＇ effect on cutting performance, which show that optimized cutting parameters and cutting model can significantly improve the prediction of the cutting ability and quality of ASJ.展开更多
The woven textile sandwich composite（WTSC） is a promising lightweight composite.In bending,two competing core shearing failure modes reduce the strength;deflection induced by the core shearing deformation reduces th...The woven textile sandwich composite（WTSC） is a promising lightweight composite.In bending,two competing core shearing failure modes reduce the strength;deflection induced by the core shearing deformation reduces the flexural rigidity.To replace a solid composite laminate,the span of WTSC panel must be greater than a critical value,which was deduced on the condition that the load capacity and flexural rigidity of the WTSC panel are equal to those of the composite laminate.Three WTSC panels were tested in bending,so that the failure modes were observed,and the critical spans were determined.Using the alternative design method,the WTSC based wind deflector with reduced weight has been fabricated and mounted on the CRH（China Railway High-speed）.展开更多
There are many various kinds of English language tests in the world,ranging from IELTS(International English Lan⁃guage Testing System)to TOEFL(Test of English as a Foreign Language).All these tests are designed for di...There are many various kinds of English language tests in the world,ranging from IELTS(International English Lan⁃guage Testing System)to TOEFL(Test of English as a Foreign Language).All these tests are designed for different purposes relat⁃ing to various groups of testees.Usually the English language test covers the testing of the four language skills of reading,writing,listening and speaking.The essay will discuss the relationship between the nature of four skills and the test design respectively.展开更多
By analyzing the shortage of reliability test design and thinking over the producer's risk and consumer's risk, the information fusion technology is used to set up a reliability test design model( RTDM). By an...By analyzing the shortage of reliability test design and thinking over the producer's risk and consumer's risk, the information fusion technology is used to set up a reliability test design model( RTDM). By analyzing the demands and constraint conditions of the RTDM and with applications of Bayesian approach and Monte Carlo method( MCM),this paper puts forward the exponential distributed subsystems and the information fusion technology among them. According to the posteriori risk criteria,formulas of producer's risk and consumer's risk were also inferred,and with the help of Matlab software,selection of the optimum test plan was solved. Finally,validity of the model had been proved by a test of series parallel system.展开更多
With the development of VLSI technology, testing design method has been one indispensable fact of the research of VLSI design methodology. Technology of testing design can observably reduce the cost of the chip and he...With the development of VLSI technology, testing design method has been one indispensable fact of the research of VLSI design methodology. Technology of testing design can observably reduce the cost of the chip and help win in time- to-market. Conventional methods of design for test improve the testing performance of the system by modifing the gate-level architecture generally. Re-search in high-level test synthesis has been emphasized on fitting for the trend of high-level VLSI design. In this paper, based on the analysis of different types of testing design methods, a novel compound strategy of design for test in VLSI system is proposed.展开更多
The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different f...The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different from the previous reports have been concluded: (1)both the degrees of freedom of the orthogonal terms C2 and C3 are m, (2)the denominator in the F test to C2 and C3 is the error mean of square between plots.展开更多
Accelerated life testing(ALT)has been widely used to obtain information about the product's life characteristics at normal conditions in a relatively short period of time.Two key issues with ALT are test design an...Accelerated life testing(ALT)has been widely used to obtain information about the product's life characteristics at normal conditions in a relatively short period of time.Two key issues with ALT are test design and data analysis.The test design of constant stress ALT was studied in this paper.The test design usually combines engineering experiences with optimization models.Such approaches are hard to be implemented by practitioners.A"pure"empirical approach was presented to address this issue.With the proposed approach,some of the decision variables are determined based on the results from the literature,some of the other variables are determined based on engineering analysis and /or judgment,and the remaining variables are determined based on the empirical relations developed in this paper.A real-world example is included to illustrate the appropriateness of the proposed approach.展开更多
In order to improve the system reliability and performance and to reduce the system cost, volume and weight, we have designed, fabricated and tested the multibus adapter system of a trimodular redundant fault tolerant...In order to improve the system reliability and performance and to reduce the system cost, volume and weight, we have designed, fabricated and tested the multibus adapter system of a trimodular redundant fault tolerant computer system on a single chip of 5000 gate CMOS gate array. The design, fabrication and test of this single chip system will be discussed..展开更多
The function of the UHVDC test base of the State Grid Corporation of China (SGCC) is oriented to serve UHVDC power transmission and substation projects, especially power transmission from West China to East China, and...The function of the UHVDC test base of the State Grid Corporation of China (SGCC) is oriented to serve UHVDC power transmission and substation projects, especially power transmission from West China to East China, and to promote localization of UHVDC transmission and substation equipment. In essentials, this test base consists of UHVDC test transmission line, corona cage, outdoor test site, UHV test hall, pollution and environment laboratory, electromagnetic environment simulation test site, insulator laboratory, arrester laboratory and live equipment test field. This paper introduces the function and design idea of the test base, presents the main performance parameters of the above-mentioned test facilities, and summarizes the matters of concern when siting and planning.展开更多
China’s Ministry of Commerce(MOFCOM)and the Ministry of Industry and Information Technology(MIIT)have designed a stress-test for China’s labor-intensive industries,
The UHVAC 1 000-kV transmission system is so far the one with the most advanced transmission technique applied and highest operation voltage.There are no guidelines or standards available for the design of 1 000-kV ov...The UHVAC 1 000-kV transmission system is so far the one with the most advanced transmission technique applied and highest operation voltage.There are no guidelines or standards available for the design of 1 000-kV overhead transmission line in China.Study on key technologies and design schemes shall be carried out to ascertain the technical principles and construction standards for project construction,which are presented in this paper based on the Southeast Shanxi-Nanyang-Jingmen test and demonstration transmission line.A comparison and analysis of technical data and economic indices between UHV line and other lines are also described.展开更多
The helium cooled solid breeder blanket that represents the main stream in relevant blanket concepts. It is considered as one of the main options for the fusion reactor. This concept have advantage as follows： （ 1 ...The helium cooled solid breeder blanket that represents the main stream in relevant blanket concepts. It is considered as one of the main options for the fusion reactor. This concept have advantage as follows： （ 1 ） structure simpleness and stability, （ 2 ） no effect of MHD, （ 3 ） a good compatibility in different materials.展开更多
Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email server.In this paper,we propose a blockchain-based certificateless bidirectio...Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email server.In this paper,we propose a blockchain-based certificateless bidirectional authenticated searchable encryption model for a cloud email system named certificateless authenticated bidirectional searchable encryption(CL-BSE)by combining the storage function of cloud server with the communication function of email server.In the new model,not only can the data receiver search for the relevant content by generating its own trapdoor,but the data owner also can retrieve the content in the same way.Meanwhile,there are dual authentication functions in our model.First,during encryption,the data owner uses the private key to authenticate their identity,ensuring that only legal owner can generate the keyword ciphertext.Second,the blockchain verifies the data owner’s identity by the received ciphertext,allowing only authorized members to store their data in the server and avoiding unnecessary storage space consumption.We obtain a formal definition of CL-BSE and formulate a specific scheme from the new system model.Then the security of the scheme is analyzed based on the formalized security model.The results demonstrate that the scheme achieves multikeyword ciphertext indistinguishability andmulti-keyword trapdoor privacy against any adversary simultaneously.In addition,performance evaluation shows that the new scheme has higher computational and communication efficiency by comparing it with some existing ones.展开更多
For mechanized picking of ground jujube under thick planting mode,there arise such issues as ease of damage and inefficient and difficult separation from impurities.In view of this,a bionic arm ground jujube picker wa...For mechanized picking of ground jujube under thick planting mode,there arise such issues as ease of damage and inefficient and difficult separation from impurities.In view of this,a bionic arm ground jujube picker was designed on the basis of analyzing jujube planting mode and characteristics,the structural parameters of its key components were determined,and a characteristic model for airflow in the internal flow field of the cleaning system and a movement trajectory model of the gathering device were established.A quadratic orthogonal center composite test was carried out to establish the regression models between influencing factors and the performance of the picker,and analyze the influence law of these factors on the picker.In this test,ground jujubes were taken as the picking object;the forward speed of the picker,the fan speed,and the height of the picking mouth from the ground were taken as the influencing factors;and the picking rate and the impurity rate were taken as the performance indices of the picker.The optimal combination of parameters was determined by multi-objective optimization(MOD):the forward speed of the picker was 0.47 m/s,the fan speed was 3025.76 r/min,and the height of the picking mouth from the ground was 84.20 mm.At this time,the picking rate of the picker was 94.00%,and the impurity rate was 2.30%.According to test verification,the test results and optimization results were consistent,meeting the requirements of mechanized picking of ground jujube.展开更多
Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system s...Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.展开更多
Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesi...Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesium alloy by means of orthogonal test design method. The results show that pouring temperature, mould temperature and squeeze velocity can significantly affect the fluidity of magnesium alloy specimens with wall thickness no more than 4 ram, and the pouring temperature is the most influential factor on the fluidity of specimens with wall thickness of 1, 2 and 3 mm, while mould temperature is the one for specimens with wall thickness of 4 mm. Increasing pouring temperature between 700 ℃ and 750 ℃ is beneficial to the fluidity of AZ91D magnesium alloy, and increasing mould temperature significantly enhances the filling ability of thick （3 and 4 mm） section castings. The fluidity of squeeze cast magnesium alloy increases with the increase of wall thickness. It is not recommended to produce magnesium alloy casting with wall thickness of smaller than 3 mm by squeeze cast process due to the poor fluidity. The software DPS was used to generate the regression model, and linear regression equations of the fluidity of squeeze cast AZ91D with different wall thicknesses are obtained using the test results.展开更多
To realize the widespread application and continuous functional development of intelligent vehicles,test and evaluation of vehicle's functionality and Safety Performance in complex off-road scenarios are fundament...To realize the widespread application and continuous functional development of intelligent vehicles,test and evaluation of vehicle's functionality and Safety Performance in complex off-road scenarios are fundamental.Since traditional distance-based road tests cannot meet the evolving test requirements,a method to design the function-based off-road testing scenario library for intelligent vehicles(IV)is proposed in this paper.The testing scenario library is defined as a critical set of scenarios that can be used for IV tests.First,for the complex and diverse off-road scenarios,a hierarchical,structural model of the test scenario is built.Then,the critical test scenarios are selected adaptively according to the vehicle model to be tested.Next,those parameters representing the challenging test scenarios are selected.The selected parameters need to fit the natural distribution probability of scenarios.The critical test-scenario library is built combing these parameters with the structural model.Finally,the test scenarios that are most approximate to the natural driving scenario are determined with importance sampling theory.The test-scenario library built with this method can provide more critical test scenarios,and is widely applicable despite different vehicle models.Verified by simulation in the off-road interaction scenarios,test would be accelerated significantly with this method,about 800 times faster than testing in the natural road environment.展开更多
文摘The robust parameter design method is a traditional approach to robust experimental design that seeks to obtain the optimal combination of factors/levels. To overcome some of the defects of the inflatable wing parameter design method, this paper proposes an optimization design scheme based on orthogonal testing and support vector machines （SVMs）. Orthogonal testing design is used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iterations and improve the identification accuracy and efficiency. Orthogonal tests consisting of three factors and three levels are designed to analyze the parameters of pressure, uniform applied load and the number of chambers that affect the bending response of inflatable wings. An SVM intelligent model is established and limited orthogonal test swatches are studied. Thus, the precise relationships between each parameter and product quality features, as well the signal-to-noise ratio （SNR）, can be obtained. This can guide general technological design optimization.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFD2000100)Science and Technology Development Plan Project of Jilin Province(20240303037NC)+2 种基金Project of Education Department of Jilin Province(JJKH20241313HT)Intelligent Control System of Variable Fertilization of Deep Application Liquid Fertilizer(GXKS2022GKY003)Key Laboratory of Detection Technology for Sugarcane and Peanut Leaf Spot Disease at Guangxi Science and Technology Normal University(GXKSKYPT2025008).
文摘In light of the shortcomings in soil compaction observed in ridge cultivation following seeding in Northeast China,it was deemed necessary to develop a solution that would address the issue of soil moisture conservation and temperature control on the seedbed.The slide vibrational compaction device(SVPD),which is capable of compacting the upper and lateral soil of the ridge,was thus designed.The device features adjustable parameters,including an upper compacting plate inlet width of 260-360 mm,an outlet width of 230-290 mm,and a side compacting plate width of 140-240 mm.Its key components include an eccentric block generating vibratory force,a spring system with adjustable stiffness for controlled compaction,and compacting plates designed for uniform soil coverage.The optimal working parameters were determined to be an eccentric block angle of 36.00°,spring stiffness of 46.00 N/mm,and an upper plate exit width of 284.00 mm.The device achieves soil bulk densities of 1.206 g/cm^(3)on the ridge and 1.148 g/cm^(3)on the ridge side,significantly improving compaction compared to traditional methods,and increasing maize yield by 5%.Therefore,in order to meet the agronomic requirements of soil bulk density for crop growth on the ridge,the sliding vibration compacting device also achieves effective compaction of the soil on the ridge side,providing effective technical support for crop emergence and growth under the monoculture planting pattern in Northeastern China.
基金supported by the Science and Technology Development Foundation of Shanghai Municipal Science and Technology Commission (Grant No.037252022)
文摘This paper describes the application of orthogonal test design coupled with non-linear regression analysis to optimize abrasive suspension jet （AS J） cutting process and construct its cutting model. Orthogonal test design is applied to cutting stainless steel. Through range analysis on experiment results, the optimal process conditions for the cutting depth and the kerr ratio of the bottom width to the top width can be determined. In addition, the analysis of ranges and variances are all employed to identify various factors： traverse rate, working pressure, nozzle diameter, standoff distance which denote the importance order of the cutting parameters affecting cutting depth and the kerf ratio of the bottom width to the top width. ~rthermore, non-linear regression analysis is used to establish the mathematical models of the cutting parameters based on the cutting depth and the kerr ratio. Finally, the verification experiments of cutting parameters＇ effect on cutting performance, which show that optimized cutting parameters and cutting model can significantly improve the prediction of the cutting ability and quality of ASJ.
基金Project supported by the National Natural Science Foundation of China(Nos.11172089 and 11372095)the State Key Laboratory of Mechanics and Control of Mechanical Structures(Nos.MCMS-0212G01 and MCMS-0215G01)
文摘The woven textile sandwich composite（WTSC） is a promising lightweight composite.In bending,two competing core shearing failure modes reduce the strength;deflection induced by the core shearing deformation reduces the flexural rigidity.To replace a solid composite laminate,the span of WTSC panel must be greater than a critical value,which was deduced on the condition that the load capacity and flexural rigidity of the WTSC panel are equal to those of the composite laminate.Three WTSC panels were tested in bending,so that the failure modes were observed,and the critical spans were determined.Using the alternative design method,the WTSC based wind deflector with reduced weight has been fabricated and mounted on the CRH（China Railway High-speed）.
文摘There are many various kinds of English language tests in the world,ranging from IELTS(International English Lan⁃guage Testing System)to TOEFL(Test of English as a Foreign Language).All these tests are designed for different purposes relat⁃ing to various groups of testees.Usually the English language test covers the testing of the four language skills of reading,writing,listening and speaking.The essay will discuss the relationship between the nature of four skills and the test design respectively.
基金National Natural Science Foundation of China(No.70971133)
文摘By analyzing the shortage of reliability test design and thinking over the producer's risk and consumer's risk, the information fusion technology is used to set up a reliability test design model( RTDM). By analyzing the demands and constraint conditions of the RTDM and with applications of Bayesian approach and Monte Carlo method( MCM),this paper puts forward the exponential distributed subsystems and the information fusion technology among them. According to the posteriori risk criteria,formulas of producer's risk and consumer's risk were also inferred,and with the help of Matlab software,selection of the optimum test plan was solved. Finally,validity of the model had been proved by a test of series parallel system.
文摘With the development of VLSI technology, testing design method has been one indispensable fact of the research of VLSI design methodology. Technology of testing design can observably reduce the cost of the chip and help win in time- to-market. Conventional methods of design for test improve the testing performance of the system by modifing the gate-level architecture generally. Re-search in high-level test synthesis has been emphasized on fitting for the trend of high-level VLSI design. In this paper, based on the analysis of different types of testing design methods, a novel compound strategy of design for test in VLSI system is proposed.
文摘The analysis method of the triple test cross design has been discussed carefully from the two factor experiment design and the genetic models of additive dominant effect and of epistasis effect.Two points different from the previous reports have been concluded: (1)both the degrees of freedom of the orthogonal terms C2 and C3 are m, (2)the denominator in the F test to C2 and C3 is the error mean of square between plots.
基金National Natural Science Foundation of China(No.71371035)
文摘Accelerated life testing(ALT)has been widely used to obtain information about the product's life characteristics at normal conditions in a relatively short period of time.Two key issues with ALT are test design and data analysis.The test design of constant stress ALT was studied in this paper.The test design usually combines engineering experiences with optimization models.Such approaches are hard to be implemented by practitioners.A"pure"empirical approach was presented to address this issue.With the proposed approach,some of the decision variables are determined based on the results from the literature,some of the other variables are determined based on engineering analysis and /or judgment,and the remaining variables are determined based on the empirical relations developed in this paper.A real-world example is included to illustrate the appropriateness of the proposed approach.
文摘In order to improve the system reliability and performance and to reduce the system cost, volume and weight, we have designed, fabricated and tested the multibus adapter system of a trimodular redundant fault tolerant computer system on a single chip of 5000 gate CMOS gate array. The design, fabrication and test of this single chip system will be discussed..
文摘The function of the UHVDC test base of the State Grid Corporation of China (SGCC) is oriented to serve UHVDC power transmission and substation projects, especially power transmission from West China to East China, and to promote localization of UHVDC transmission and substation equipment. In essentials, this test base consists of UHVDC test transmission line, corona cage, outdoor test site, UHV test hall, pollution and environment laboratory, electromagnetic environment simulation test site, insulator laboratory, arrester laboratory and live equipment test field. This paper introduces the function and design idea of the test base, presents the main performance parameters of the above-mentioned test facilities, and summarizes the matters of concern when siting and planning.
文摘China’s Ministry of Commerce(MOFCOM)and the Ministry of Industry and Information Technology(MIIT)have designed a stress-test for China’s labor-intensive industries,
文摘The UHVAC 1 000-kV transmission system is so far the one with the most advanced transmission technique applied and highest operation voltage.There are no guidelines or standards available for the design of 1 000-kV overhead transmission line in China.Study on key technologies and design schemes shall be carried out to ascertain the technical principles and construction standards for project construction,which are presented in this paper based on the Southeast Shanxi-Nanyang-Jingmen test and demonstration transmission line.A comparison and analysis of technical data and economic indices between UHV line and other lines are also described.
文摘The helium cooled solid breeder blanket that represents the main stream in relevant blanket concepts. It is considered as one of the main options for the fusion reactor. This concept have advantage as follows： （ 1 ） structure simpleness and stability, （ 2 ） no effect of MHD, （ 3 ） a good compatibility in different materials.
基金supported by the National Natural Science Foundation of China(Nos.62172337,62241207)Key Project of GansuNatural Science Foundation(No.23JRRA685).
文摘Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email server.In this paper,we propose a blockchain-based certificateless bidirectional authenticated searchable encryption model for a cloud email system named certificateless authenticated bidirectional searchable encryption(CL-BSE)by combining the storage function of cloud server with the communication function of email server.In the new model,not only can the data receiver search for the relevant content by generating its own trapdoor,but the data owner also can retrieve the content in the same way.Meanwhile,there are dual authentication functions in our model.First,during encryption,the data owner uses the private key to authenticate their identity,ensuring that only legal owner can generate the keyword ciphertext.Second,the blockchain verifies the data owner’s identity by the received ciphertext,allowing only authorized members to store their data in the server and avoiding unnecessary storage space consumption.We obtain a formal definition of CL-BSE and formulate a specific scheme from the new system model.Then the security of the scheme is analyzed based on the formalized security model.The results demonstrate that the scheme achieves multikeyword ciphertext indistinguishability andmulti-keyword trapdoor privacy against any adversary simultaneously.In addition,performance evaluation shows that the new scheme has higher computational and communication efficiency by comparing it with some existing ones.
基金funded by Key projects at the university level(ZZ202401)Xinjiang“Tianchi Talents”Introduction Programme Funding Project(Letter from the Xinjiang Department of Human Resources and Social Security[2024]No.57)(2023TCLJ03)Xinjiang Specialty Food Processing Equipment R&D Centre(PT202104).
文摘For mechanized picking of ground jujube under thick planting mode,there arise such issues as ease of damage and inefficient and difficult separation from impurities.In view of this,a bionic arm ground jujube picker was designed on the basis of analyzing jujube planting mode and characteristics,the structural parameters of its key components were determined,and a characteristic model for airflow in the internal flow field of the cleaning system and a movement trajectory model of the gathering device were established.A quadratic orthogonal center composite test was carried out to establish the regression models between influencing factors and the performance of the picker,and analyze the influence law of these factors on the picker.In this test,ground jujubes were taken as the picking object;the forward speed of the picker,the fan speed,and the height of the picking mouth from the ground were taken as the influencing factors;and the picking rate and the impurity rate were taken as the performance indices of the picker.The optimal combination of parameters was determined by multi-objective optimization(MOD):the forward speed of the picker was 0.47 m/s,the fan speed was 3025.76 r/min,and the height of the picking mouth from the ground was 84.20 mm.At this time,the picking rate of the picker was 94.00%,and the impurity rate was 2.30%.According to test verification,the test results and optimization results were consistent,meeting the requirements of mechanized picking of ground jujube.
基金Supported by National Natural Science Foundation of China(Grant No.51605417)Key Project of Hebei Provincial Natural Science Foundation,China(Grant No.E2016203264)State Key Laboratory of Fluid Power and Mechatronic Systems(Zhejiang University)Open Fund Project(Grant No.GZKF-201502)
文摘Nowadays, a highly integrated valve?controlled cylinder(HIVC) is applied to drive the joints of legged robots. Although the adoption of HIVC has resulted in high?performance robot control, the hydraulic force system still has problems, such as strong nonlinearity, and time?varying parameters. This makes HIVC force control very diffcult and complex. How to improve the control performance of the HIVC force control system and find the influence rule of the system parameters on the control performance is very significant. Firstly, the mathematical model of HIVC force control system is established. Then the mathematical expression for parameter sensitivity matrix is obtained by applying matrix sensitivity analysis(PSM). Then, aimed at the sinusoidal response under(three factors and three levels) working conditions, the simulation and the experiment are conducted. While the error between the simulation and experiment can’t be avoided. Therefore, combined with the range analysis, the error in the two performance indexes of sinusoidal response under the whole working condition is analyzed. Besides, the sensitivity variation pattern for each system parameter under the whole working condition is figured out. Then the two sensitivity indexes for the three system parameters, which are supply pressure, proportional gain and initial displacement of piston, are proved experimentally. The proposed method significantly reveals the sensitivity characteristics of HIVC force control system, which can make the contribution to improve the control performance.
基金the open program of State Key Laboratory of Materials Processing and Die&Mould Technology(No.08-04),Huazhong University of Science and Technology,China
文摘Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesium alloy by means of orthogonal test design method. The results show that pouring temperature, mould temperature and squeeze velocity can significantly affect the fluidity of magnesium alloy specimens with wall thickness no more than 4 ram, and the pouring temperature is the most influential factor on the fluidity of specimens with wall thickness of 1, 2 and 3 mm, while mould temperature is the one for specimens with wall thickness of 4 mm. Increasing pouring temperature between 700 ℃ and 750 ℃ is beneficial to the fluidity of AZ91D magnesium alloy, and increasing mould temperature significantly enhances the filling ability of thick （3 and 4 mm） section castings. The fluidity of squeeze cast magnesium alloy increases with the increase of wall thickness. It is not recommended to produce magnesium alloy casting with wall thickness of smaller than 3 mm by squeeze cast process due to the poor fluidity. The software DPS was used to generate the regression model, and linear regression equations of the fluidity of squeeze cast AZ91D with different wall thicknesses are obtained using the test results.
基金National Natural Science Foundation of China No.U19A2083.
文摘To realize the widespread application and continuous functional development of intelligent vehicles,test and evaluation of vehicle's functionality and Safety Performance in complex off-road scenarios are fundamental.Since traditional distance-based road tests cannot meet the evolving test requirements,a method to design the function-based off-road testing scenario library for intelligent vehicles(IV)is proposed in this paper.The testing scenario library is defined as a critical set of scenarios that can be used for IV tests.First,for the complex and diverse off-road scenarios,a hierarchical,structural model of the test scenario is built.Then,the critical test scenarios are selected adaptively according to the vehicle model to be tested.Next,those parameters representing the challenging test scenarios are selected.The selected parameters need to fit the natural distribution probability of scenarios.The critical test-scenario library is built combing these parameters with the structural model.Finally,the test scenarios that are most approximate to the natural driving scenario are determined with importance sampling theory.The test-scenario library built with this method can provide more critical test scenarios,and is widely applicable despite different vehicle models.Verified by simulation in the off-road interaction scenarios,test would be accelerated significantly with this method,about 800 times faster than testing in the natural road environment.
