A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynami...A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynamic-mechanical transmission is built in MATLAB/Simdriveline environment, and an optimum shift schedule is derived by using iSight software to call the dynamic model above, then the shift schedule is achieved after optimization. The simulation results show that the method is significant to improve the dynamic performance and gear-shifting smoothness theoretically and practically.展开更多
A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony(ABC) algorithm with biogeography-based optimization(BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO c...A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony(ABC) algorithm with biogeography-based optimization(BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO combined the exploration of ABC algorithm with the exploitation of BBO algorithm effectively, and hence it can generate the promising candidate individuals. The proposed hybrid algorithm speeds up the convergence and improves the algorithm's performance. Several benchmark test functions and mechanical design problems are applied to verifying the effects of these improvements and it is demonstrated that the performance of this proposed ABC-BBO is superior to or at least highly competitive with other population-based optimization approaches.展开更多
In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec han...In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.展开更多
The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w ear...The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w earing greatly, and the surface quality of the product is improved to the utmost extent. The design mechanism of the optimal cutting movement trajectory system structure is analyzed incisively. At the same time, the principle of the complex movement of horizontal movement and swing is researched. The optimal design scheme of th e cutting movement trajectory system structure is set up. The choice method to g et the superior value of the movement system structure is found. The mathematics function formula is established which exhibits the relationship between the par ameter of the complex movement structure and that of the system movement structu re. By the formula, the precision value of the offset can be figured out. The r ule is adapted to different types of energy-saving stone-sawing machines. The complex movement structure of horizontal movement and swing is designed to f ulfill the cutting movement. It can make the saw frame move up with the hanging pod deviating from the vertical direction. At the same time, the saw frame have a down-movement. Then the sum of the two movements is near to zero, and the saw blade and the stone can keep in touch during the whole horizontal cutting. The result is that the actual cutting efficiency is 100%. Also, when the hanging pod moves to the limited position, the saw frame can keep the original inertia, and continue to swing up. It makes the back-cutting have high energy-storing. The optimal design of the eccentricity balance wheel is done. The mathematics fo rmula for expressing the movement system structure is deduced. The calculation m ethod and formula is set up which is used to get the value of important componen ts such as offset. The choice method and formula of elasticity distortion coeffi cient is set up when the saw frame moves smoothly. It is concluded that the offs et is the key dimension to actualize the optimal cutting movement trajectory. The resolving of the technical problems discussed above offers a theoretic and technical basis for optimal design of energy-saving stone-sawing machines.展开更多
By phenomenological analysis of warm compaction, it is found that, compared with the contribution of particle plastical deformation to densification of powder compact,the particle rearrangement is a dominant densifica...By phenomenological analysis of warm compaction, it is found that, compared with the contribution of particle plastical deformation to densification of powder compact,the particle rearrangement is a dominant densification mechanism for powder warm compaction, and the plastical deformation of particles plays an important role in offering accommodating deformation for particle rearrangement and densifying powder compact at the final stage of pressing.In order to attain density gain as high as possible during warm compaction, six rules for designing warm compacting powder mixtures were proposed in detail.展开更多
In order to achieve the functional requirements of multi-moving state, a new autonomous underwater vehicle(AUV) provided with the functions such as the submarine vectorial thrust, landing on the sea bottom, wheel driv...In order to achieve the functional requirements of multi-moving state, a new autonomous underwater vehicle(AUV) provided with the functions such as the submarine vectorial thrust, landing on the sea bottom, wheel driving on the ground and crawling on the ground was designed. Then five new theories and methods were proposed about the motion mechanism of the AUV such as vectorial thruster technology, design of a new wheel propeller, kinematics and dynamics, navigation control and the ambient flow field in complex sea conditions, which can all conquer conventional technique shortages and predict the multi-moving state performance under wave disturbance. The theoretical research can realize the results such as a vectorial transmission shaft with the characteristics of spatial deflexion and continual circumgyratetion, parameterized design of the new wheel propeller with preferable open-water performance and intensity characteristics satisfying multi-moving state requirements, motion computation and kinetic analysis of AUV's arbitrary postures under wave disturbance, a second-order sliding mode controller with double-loop structure based on dynamic boundary layer that ensures AUV's trajectory high-precision tracking performance under wave disturbance, fast and exact prediction of the ambient flow field characteristics and the interaction mechanism between AUV hull and wheel propellers. The elaborate data obtained from the theoretical research can provide an important theoretical guidance and technical support for the manufacture of experimental prototype.展开更多
Background Coronary artery stenting is commonly used for the treatment of coronary atherosclerosis,but it causes serious clinical complications,such as the in-stent restenosis(ISR).The main reason leading to ISR is th...Background Coronary artery stenting is commonly used for the treatment of coronary atherosclerosis,but it causes serious clinical complications,such as the in-stent restenosis(ISR).The main reason leading to ISR is the neointimal hyperplasia(NH),which is related to the stresses of plaque and artery,and to the altered local hemodynamic environment due to the presence of stents.Different stent structures indeed have various impacts on the stresses of plaque and artery,and the local hemodynamic environment,such as the wall shear stress(WSS),average WSS(AWSS),and WSS gradient(WSSG).Thus,it is important to evaluate the performance of stents with different structures by the mechanical factors after coronary stenting.Methods Six stents implanted into a stenotic curved coronary artery were treated separately,and they included three typical commercial stents(Palmaz-Schatz,Xience,and Cypher)and three author-developed stents,which were constructed by reducing the numbers of link(C-Rlink)and crown(C-Rcrown),and aligning the strut(C-Astrut)of the commercial Cypher Solid mechanical analyses of the balloon-stent-plaque-artery system in Abaqus were first performed to assess the performance of different stent structures and provide the deformed boundary of lumen for the subsequent hemodynamic analysis.With the deformed boundary,then hemodynamic analyses in Ansys were conducted to quanti-fy the hemodynamic parameters induced by different stent structures.Combining the solid mechanical and hemodynamic analyses,the performance of the six stents was evaluated.Results The results show that among the three commercial stents,the Palmaz-Schatz stent has the least stent dogboning and recoiling,which corresponds to the greatest maximum plastic strain as well as the largest diameter.However,it induces the greatest maximum stress of plaque,intima,and media.From the viewpoint of hemodynamics,the Palmaz-Schatz stent also performs better and it has smaller areas of adverse low WSS(<0.5 Pa),high WSS(>15 Pa),low AWSS(<0.5 Pa),and high WSSG(>5 000 Pa/m).Compared to the commercial Cypher stent,the author-developed Cypher-based C-Rcrown and C-Astrut stents have smaller recoiling,greater maximum plastic stain and larger diameter,which indicates the improved mechanical performance of the Cypher stent.Moreover,both C-Rcrown and C-Astrut have smaller areas of adverse low WSS,high WSS,and low AWSS,but only C-Rcrown has smaller area of adverse high WSSG.Nevertheless,the C-Rlink stent is inferior to the commercial Cypher stent.In both senses of the solid mechanical and local hemodynamic analyses,the C-Rcrown stent is superior to the commercial Cypher stent and other Cypher-based stents.Conclusions In this study,solid mechanical and hemodynamic analyses were carried out to study the effects of six stents with different structures on their performances after stenting.It was found that the Palmaz-Schatz stent performed better than other two commercial stents,and the performance of the Cypher stent could be improved by reducing the number of crowns of its strut.The present study comparatively evaluates the performance of different stents inside a curved artery,and could be used as a guide to select a suitable commercial stent for clinical application,and provide a way to improve the performance of the existing commercial stents.展开更多
以基因、转录、蛋白质等生命组学为主体的生物大数据快速积累和以深度学习为代表的人工智能技术迅猛发展,催生出各种类别的生物大模型(biological large models)。复杂的深度学习架构、巨大的参数量和算力需求、以及海量的预训练数据等...以基因、转录、蛋白质等生命组学为主体的生物大数据快速积累和以深度学习为代表的人工智能技术迅猛发展,催生出各种类别的生物大模型(biological large models)。复杂的深度学习架构、巨大的参数量和算力需求、以及海量的预训练数据等是大模型技术的主要特征。预训练数据类别及参数量一定程度上决定了大模型所具备的能力强弱,而不同的模型架构则可支撑不同类别的下游任务。近两年,围绕DNA/RNA/蛋白质等生物序列与单细胞表达图谱等组学数据分析挖掘、大分子结构预测、新型药物设计和功能机制解析等多种应用场景,涌现了多种通用或专用大模型,展示出其在生物医学研究及转化应用等领域的巨大潜力。本文旨在结合不同类别的生物数据特点和研究应用需求,概述生物数据特征及其用于生物大模型训练的技术方法,并进一步综述现有大模型在生物医学研究及疾病诊疗中的应用进展,为提升生物大模型能力、拓展应用范围提供新的思路。展开更多
基金Sponsored by the National Natural Science Foudation of China(50905016)
文摘A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynamic-mechanical transmission is built in MATLAB/Simdriveline environment, and an optimum shift schedule is derived by using iSight software to call the dynamic model above, then the shift schedule is achieved after optimization. The simulation results show that the method is significant to improve the dynamic performance and gear-shifting smoothness theoretically and practically.
基金Projects(61463009,11264005,11361014)supported by the National Natural Science Foundation of ChinaProject([2013]2082)supported by the Science Technology Foundation of Guizhou Province,China
文摘A novel hybrid algorithm named ABC-BBO, which integrates artificial bee colony(ABC) algorithm with biogeography-based optimization(BBO) algorithm, is proposed to solve constrained mechanical design problems. ABC-BBO combined the exploration of ABC algorithm with the exploitation of BBO algorithm effectively, and hence it can generate the promising candidate individuals. The proposed hybrid algorithm speeds up the convergence and improves the algorithm's performance. Several benchmark test functions and mechanical design problems are applied to verifying the effects of these improvements and it is demonstrated that the performance of this proposed ABC-BBO is superior to or at least highly competitive with other population-based optimization approaches.
文摘In this paper, a Web-based Mechanical Design and A na lysis Framework (WMDAF) is proposed. This WMADF allows designers to develop web -based computer aided programs in a systematic way during the collaborative mec hanical system design and analysis process. This system is based on an emerg ing web-based Content Management System (CMS) called eXtended Object Oriented P ortal System (XOOPS). Due to the Open Source Status of the XOOPS CMS, programs d eveloped with this framework can be further customized to satisfy the demands of the user. To introduce the use of this framework, this paper exams three differ ent types of mechanical design and analysis problems. First, a repetitive design consideration and calculation process is transferred into WMADF programs to gai n efficiency for wired collaborative team. Second, the considered product solid model is created directly through the use of XOOPS program and Microsoft Compone nt Object Model (COM) instances. To the end of the paper, an example linked with ANSYS is used to indicate the possible application of this framework.
文摘The technique of cutting slabstone with stone-sawi ng machine is analyzed completely. A new kind of cutting movement trajectory is gi ven whose actual cutting efficiency is near to 100%. It can reduce the energy w earing greatly, and the surface quality of the product is improved to the utmost extent. The design mechanism of the optimal cutting movement trajectory system structure is analyzed incisively. At the same time, the principle of the complex movement of horizontal movement and swing is researched. The optimal design scheme of th e cutting movement trajectory system structure is set up. The choice method to g et the superior value of the movement system structure is found. The mathematics function formula is established which exhibits the relationship between the par ameter of the complex movement structure and that of the system movement structu re. By the formula, the precision value of the offset can be figured out. The r ule is adapted to different types of energy-saving stone-sawing machines. The complex movement structure of horizontal movement and swing is designed to f ulfill the cutting movement. It can make the saw frame move up with the hanging pod deviating from the vertical direction. At the same time, the saw frame have a down-movement. Then the sum of the two movements is near to zero, and the saw blade and the stone can keep in touch during the whole horizontal cutting. The result is that the actual cutting efficiency is 100%. Also, when the hanging pod moves to the limited position, the saw frame can keep the original inertia, and continue to swing up. It makes the back-cutting have high energy-storing. The optimal design of the eccentricity balance wheel is done. The mathematics fo rmula for expressing the movement system structure is deduced. The calculation m ethod and formula is set up which is used to get the value of important componen ts such as offset. The choice method and formula of elasticity distortion coeffi cient is set up when the saw frame moves smoothly. It is concluded that the offs et is the key dimension to actualize the optimal cutting movement trajectory. The resolving of the technical problems discussed above offers a theoretic and technical basis for optimal design of energy-saving stone-sawing machines.
文摘By phenomenological analysis of warm compaction, it is found that, compared with the contribution of particle plastical deformation to densification of powder compact,the particle rearrangement is a dominant densification mechanism for powder warm compaction, and the plastical deformation of particles plays an important role in offering accommodating deformation for particle rearrangement and densifying powder compact at the final stage of pressing.In order to attain density gain as high as possible during warm compaction, six rules for designing warm compacting powder mixtures were proposed in detail.
基金Project(51505491)supported by the National Natural Science Foundation of ChinaProject(ZR2014EEP019)supported by the Natural Science Foundation of Shandong Province,China
文摘In order to achieve the functional requirements of multi-moving state, a new autonomous underwater vehicle(AUV) provided with the functions such as the submarine vectorial thrust, landing on the sea bottom, wheel driving on the ground and crawling on the ground was designed. Then five new theories and methods were proposed about the motion mechanism of the AUV such as vectorial thruster technology, design of a new wheel propeller, kinematics and dynamics, navigation control and the ambient flow field in complex sea conditions, which can all conquer conventional technique shortages and predict the multi-moving state performance under wave disturbance. The theoretical research can realize the results such as a vectorial transmission shaft with the characteristics of spatial deflexion and continual circumgyratetion, parameterized design of the new wheel propeller with preferable open-water performance and intensity characteristics satisfying multi-moving state requirements, motion computation and kinetic analysis of AUV's arbitrary postures under wave disturbance, a second-order sliding mode controller with double-loop structure based on dynamic boundary layer that ensures AUV's trajectory high-precision tracking performance under wave disturbance, fast and exact prediction of the ambient flow field characteristics and the interaction mechanism between AUV hull and wheel propellers. The elaborate data obtained from the theoretical research can provide an important theoretical guidance and technical support for the manufacture of experimental prototype.
基金supported by the Natural Science Foundation of China ( NSFC) ( 31300780,11272091, 11422222,31470043)supported by the National 973 Basic Research Program of China ( 2013CB733800)China scholarship Council ( 201706090121) ,and ARC ( FT140101152)
文摘Background Coronary artery stenting is commonly used for the treatment of coronary atherosclerosis,but it causes serious clinical complications,such as the in-stent restenosis(ISR).The main reason leading to ISR is the neointimal hyperplasia(NH),which is related to the stresses of plaque and artery,and to the altered local hemodynamic environment due to the presence of stents.Different stent structures indeed have various impacts on the stresses of plaque and artery,and the local hemodynamic environment,such as the wall shear stress(WSS),average WSS(AWSS),and WSS gradient(WSSG).Thus,it is important to evaluate the performance of stents with different structures by the mechanical factors after coronary stenting.Methods Six stents implanted into a stenotic curved coronary artery were treated separately,and they included three typical commercial stents(Palmaz-Schatz,Xience,and Cypher)and three author-developed stents,which were constructed by reducing the numbers of link(C-Rlink)and crown(C-Rcrown),and aligning the strut(C-Astrut)of the commercial Cypher Solid mechanical analyses of the balloon-stent-plaque-artery system in Abaqus were first performed to assess the performance of different stent structures and provide the deformed boundary of lumen for the subsequent hemodynamic analysis.With the deformed boundary,then hemodynamic analyses in Ansys were conducted to quanti-fy the hemodynamic parameters induced by different stent structures.Combining the solid mechanical and hemodynamic analyses,the performance of the six stents was evaluated.Results The results show that among the three commercial stents,the Palmaz-Schatz stent has the least stent dogboning and recoiling,which corresponds to the greatest maximum plastic strain as well as the largest diameter.However,it induces the greatest maximum stress of plaque,intima,and media.From the viewpoint of hemodynamics,the Palmaz-Schatz stent also performs better and it has smaller areas of adverse low WSS(<0.5 Pa),high WSS(>15 Pa),low AWSS(<0.5 Pa),and high WSSG(>5 000 Pa/m).Compared to the commercial Cypher stent,the author-developed Cypher-based C-Rcrown and C-Astrut stents have smaller recoiling,greater maximum plastic stain and larger diameter,which indicates the improved mechanical performance of the Cypher stent.Moreover,both C-Rcrown and C-Astrut have smaller areas of adverse low WSS,high WSS,and low AWSS,but only C-Rcrown has smaller area of adverse high WSSG.Nevertheless,the C-Rlink stent is inferior to the commercial Cypher stent.In both senses of the solid mechanical and local hemodynamic analyses,the C-Rcrown stent is superior to the commercial Cypher stent and other Cypher-based stents.Conclusions In this study,solid mechanical and hemodynamic analyses were carried out to study the effects of six stents with different structures on their performances after stenting.It was found that the Palmaz-Schatz stent performed better than other two commercial stents,and the performance of the Cypher stent could be improved by reducing the number of crowns of its strut.The present study comparatively evaluates the performance of different stents inside a curved artery,and could be used as a guide to select a suitable commercial stent for clinical application,and provide a way to improve the performance of the existing commercial stents.
文摘以基因、转录、蛋白质等生命组学为主体的生物大数据快速积累和以深度学习为代表的人工智能技术迅猛发展,催生出各种类别的生物大模型(biological large models)。复杂的深度学习架构、巨大的参数量和算力需求、以及海量的预训练数据等是大模型技术的主要特征。预训练数据类别及参数量一定程度上决定了大模型所具备的能力强弱,而不同的模型架构则可支撑不同类别的下游任务。近两年,围绕DNA/RNA/蛋白质等生物序列与单细胞表达图谱等组学数据分析挖掘、大分子结构预测、新型药物设计和功能机制解析等多种应用场景,涌现了多种通用或专用大模型,展示出其在生物医学研究及转化应用等领域的巨大潜力。本文旨在结合不同类别的生物数据特点和研究应用需求,概述生物数据特征及其用于生物大模型训练的技术方法,并进一步综述现有大模型在生物医学研究及疾病诊疗中的应用进展,为提升生物大模型能力、拓展应用范围提供新的思路。
