Soft cable-driven systems have been employed in many assembled mechanisms, such as industrial robots, parallel kinematic mechanism machines, medical devices, and humaniform hands. A pre-stretching process is necessary...Soft cable-driven systems have been employed in many assembled mechanisms, such as industrial robots, parallel kinematic mechanism machines, medical devices, and humaniform hands. A pre-stretching process is necessary to guarantee the quality of cable-driven systems during the assembly process. However, the stress relaxation of cables becomes a critical concern during long-term operation. This study investigates the effects of non-uniform deformation and long-term stress relaxation of the driven cables owing to moving parts in the system. A simple closed-loop cable-driven system is built and an alternating load is applied to it to replicate the operation of transmission cables. Under different experimental conditions, the cable tension is recorded and the boundary data are selected to be curve-fitted. Based on the fitted results, a formula is presented to estimate the stress relaxation of cables to evaluate the assembly performance. Further experimental results show that the stress relaxation is mainly caused by cable creep and the assembly procedure. To remove the influence of the assembly procedure, a modified pre-stretching assembly method based on the stress relaxation theory is proposed and verification experiments are performed. Finally, the assembly performance is optimized using a cable-driven surgical robot as an example. This paper proposes a dual stretching method instead of the pre-stretching method to assemble the cable-driven system to improve its performance and prolong its service life.展开更多
Today＇s production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industr...Today＇s production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industrial turbulent environments. Flexible automated systems are requested in order to improve dynamic production efficiency, e.g. robot-based hardware and PC-based controllers, but these usually induce a significantly higher production complexity, whereby the efforts for planning and programming, but also setups and reconfiguration, expand. In this paper a definition and some concepts of self-optimizing assembly systems are presented to describe possible ways to reduce the planning efforts in complex production systems. The concept of self-optimization in assembly systems will be derived from a theoretical approach and will be transferred to a specific application scenario---the automated assembly of a miniaturized solid state laser--where the challenges of unpredictable influences from e.g. component tolerances can be overcome by the help of self-optimization.展开更多
The failure modes and effects analysis （FMEA） is widely applied in manufacturing industries in various phases of the product life cycle to evaluate the system, its design and processes for failures that can occur. T...The failure modes and effects analysis （FMEA） is widely applied in manufacturing industries in various phases of the product life cycle to evaluate the system, its design and processes for failures that can occur. The FMEA team often demonstrates different opinions and these different types of opinions are very difficult to incorporate into the FMEA by the traditional risk priority number model. In this paper, for each of the Occurrence, Severity and Detectivity parameters a fuzzy set is defined and the opinion of each FMEA team members is considered. These opinions are considered simultaneously with weights that are given to each individual based on their skills and experience levels. In addition, the opinion of the costumer is considered for each of the FMEA parameters. Then, the Risk Priority Numbers （RPN） is calculated using a Multi Input Single Output （MISO） fuzzy expert system. The proposed model is applied for prioritizing the failures of Peugeot 206 Engine assembly line in IKCo （Iran Khodro Company）.展开更多
Porphyrins are abundant in nature. They have been frequently employed as building blocks in the construction of nanoarchitectures and functional supramolecular systems. Recently, a series of novel porphyrin molecules ...Porphyrins are abundant in nature. They have been frequently employed as building blocks in the construction of nanoarchitectures and functional supramolecular systems. Recently, a series of novel porphyrin molecules including small molecules and polymers have been originally designed and synthesized with the aim of producing nanostructures with controllable-growth and materials with high-performance. Literature coverage is through 2004-2012. This review gives a full summary of related studies in our group.展开更多
Nano assembly and manipulation technologies are the basis for nano-electro-mechanical systems（NEMS）. Atomic force microscope（AFM） is widely used to manipulate nanotubes to assemble NEMS. Manipulating nanotubes wit...Nano assembly and manipulation technologies are the basis for nano-electro-mechanical systems（NEMS）. Atomic force microscope（AFM） is widely used to manipulate nanotubes to assemble NEMS. Manipulating nanotubes with AFM is a challenging and difficult task. One of the major reasons is the deficiency of visual information during the manipulation process. To address these difficulties, this research aims to put forward novel virtual tools and assembly strategies to improve the efficiency, accuracy and ease of the assembly process of NEMS. This paper begins by the discussion of the principles and implementation of a virtual nano-assembly simulator, which serves as a benchmark to test the proposed NEMS assembly techniques and virtual tools. Then, a general framework of nanotube-based NEMS assembly is proposed. Several nano-assembly strategies and virtual tools, such as automated path planning for NEMS assembly, a four-step scheme of nanotube manipulation, virtual fixtures for assembly finalization and safe manipulation, are introduced. These virtual tools and methods are experimented for justification. An assembly task of moderate complexity was performed in our virtual nano-assembly simulator with and without the help of the proposed toolkit. Experimental results suggest that the proposed methods tend to greatly enhance the efficiency and accuracy of nanotube-based NEMS assembly. In general, the proposed virtual reality toolkit not only ensures the safety, but also enhances the accuracy and efficiency of the assembly of nanotube-based NEMS.展开更多
To solve the sequencing problem in mixed-model flexible assembly lines (MMFALs) with variable launching intervals, a mathematical model aiming to minimize the cost of utility and idle times is developed. To obtain hig...To solve the sequencing problem in mixed-model flexible assembly lines (MMFALs) with variable launching intervals, a mathematical model aiming to minimize the cost of utility and idle times is developed. To obtain high-quality sequences, an advanced scatter search (ASS) algorithm is proposed. A heuristic approach, i.e. launching intervals between products algorithm (LIBPA), is incorporated into the ASS algorithm to solve the launching interval problem for each sequence. Numerical experiments with different scales are conducted to compare the performance of ASS with genetic algorithm (GA). In addition, we compare the cost of variable launching intervals approach with fixed launching intervals approach. The results indicate that the ASS is efficient and effective, and considering variable launching intervals in mixed-model assembly lines (MMALs) sequencing problem can improve the performance of the line.展开更多
The growing global competition compels manufacturing organizations to engage themselves in all productivity improvement activities. In this direction, the consideration of mixed-model assembly line balancing problem a...The growing global competition compels manufacturing organizations to engage themselves in all productivity improvement activities. In this direction, the consideration of mixed-model assembly line balancing problem and implementing in industries plays a major role in improving organizational productivity. In this paper, the mixed model assembly line balancing problem with deterministic task times is considered. The authors made an attempt to develop a genetic algorithm for realistic design of the mixed-model assembly line balancing problem. The design is made using the originnal task times of the models, which is a realistic approach. Then, it is compared with the generally perceived design of the mixed-model assembly line balancing problem.展开更多
Presents a multi robot cooperative assembly system (MRCAS) which is composed of an organizer computer, three industrial robots, PUMA 562 mounted on an omni directional vehicle, PUMA 760 and Adept I and organized into ...Presents a multi robot cooperative assembly system (MRCAS) which is composed of an organizer computer, three industrial robots, PUMA 562 mounted on an omni directional vehicle, PUMA 760 and Adept I and organized into a hierarchical structure with the cooperation organization on the top and the coordination motion at the bottom to solve the main problem of coordination and cooperation among robots, and concludes with experimental results that MRCAS is reconfigurable and adaptable as the mission changes.展开更多
Mixed-model U-shaped assembly line balancing problems (MMUALBP) is known to be NP-hard resulting in it being nearly impossible to obtain an optimal solution for practical problems with deterministic algorithms. This p...Mixed-model U-shaped assembly line balancing problems (MMUALBP) is known to be NP-hard resulting in it being nearly impossible to obtain an optimal solution for practical problems with deterministic algorithms. This paper pre-sents a new evolutionary method called combinatorial optimisation with coincidence algorithm (COIN) being applied to Type I problems of MMUALBP in a just-in-time production system. Three objectives are simultaneously considered;minimum number workstations, minimum work relatedness, and minimum workload smoothness. The variances of COIN are also proposed, i.e. CNSGA II, and COIN-MA. COIN and its variances are tested against a well-known algo-rithm namely non-dominated sorting genetic algorithm II (NSGA II) and MNSGA II (a memetic version of NSGA II). Experimental results showed that COIN outperformed NSGA II. In addition, although COIN-MA uses a marginal CPU time than CNSGA II, its other performances are dominated.展开更多
In the SILER （Seismic-Initiated events risk mitigation in LEad-cooled Reactors） Project, it is interesting to apply seismic isolation technology for the reactor assembly of the fixed base reactor building for ADS （...In the SILER （Seismic-Initiated events risk mitigation in LEad-cooled Reactors） Project, it is interesting to apply seismic isolation technology for the reactor assembly of the fixed base reactor building for ADS （Acceleration Driven System） heavy liquid reactor MYRRHA （Multipurpose Hybrid Research Reactor for High-Tech Application） which contains the most critical safety related components, such as reactor vessel, safe shutdown and control rod mechanisms, primary heat exchangers, primary pumps, spoliation target assembly and fuel assemblies, etc. The purpose of this paper is to investigate the possibility of an application of a partial seismic isolation to the safety critical components only, here, the reactor assembly. This paper presents the preliminary analysis results of the isolated reactor assembly and compares these with those of seismic isolated ADS reactor building. The analysis results show the reduction of the seismic acceleration response but the increase of the relative displacement for the reactor assembly. Some safety issues, especially, coolant＇s incapable covering the reactor core make difficult to apply for the partial seismic isolation of the ADS reactor assembly due to large relative displacement occurring the partial isolation system. Further study on the partial seismic isolation application of the critical safety components are also discussed.展开更多
This paper gives brief introduction to the production management and control system (PMCS) for 10th assembly workshop under Xi’ an Aircraft Company (XAC)--CIMS. Its user requirements 9 structure, ftinctions, and impl...This paper gives brief introduction to the production management and control system (PMCS) for 10th assembly workshop under Xi’ an Aircraft Company (XAC)--CIMS. Its user requirements 9 structure, ftinctions, and implementation are described. It is showed that the development problems of PMCS can be further reduced to a development methodology for Chinese enterprises, which will make them competitive.展开更多
To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluatio...To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluation, the optimal structure of the turret for single-point mooring systems has been determined. Through model tests of a turret mooring system, several groups of data such as forces, moments and displacements under different environmental conditions have been obtained. Stresses and strains of the turret structure have been calculated by means of the finite element method corresponding to the situation in the model experiment. The study shows that the selected turret structure and the designed turret assembly are technically feasible.展开更多
【目的】构建方便快捷的植物表达载体。【方法】应用Isothermal in vitro recombination system or “Gibson Assem-bly”方法设计包含片段间20～25 bp互补重叠序列的引物，通过PCR扩增出带有首尾重叠的目的DNA片段，可将1个或多个片段...【目的】构建方便快捷的植物表达载体。【方法】应用Isothermal in vitro recombination system or “Gibson Assem-bly”方法设计包含片段间20～25 bp互补重叠序列的引物，通过PCR扩增出带有首尾重叠的目的DNA片段，可将1个或多个片段和线性化的载体一步组装成表达载体。【结果和结论】利用该方法快速构建了多个水稻基因的全长以及部分缺失编码区表达载体。此外，还通过对Gibson Assembly连接产物进行PCR扩增后再连接到载体，提高多DNA片段组装的效率。本方法不受目的片段内部限制性酶切位点的限制，可广泛应用于各种载体的构建。展开更多
In recent years, cancer has become the number two cause of death around the world, and scientists have exploited various treatment maps. Calixarenes, with diversified features, have been widely applied into drug deliv...In recent years, cancer has become the number two cause of death around the world, and scientists have exploited various treatment maps. Calixarenes, with diversified features, have been widely applied into drug delivery systems, which can respond to multi-stimuli and exhibit excellent performance. In this mini-review, we summarize the recent advances on controlled drug delivery systems based on calixarenes, in the form of inclusion complexes, amphiphilic self-assembly nanocarriers including micelles, hydrogels, vesicles and liposomes, and supramolecular nanovalves on mesoporous silica nanomaterials.展开更多
Artificial light-harvesting systems(LHSs) have drawn increasing research interest in recent times due to the energy crisis worldwide. Concurrently, macrocycle-based host–vip interactions have played an important ro...Artificial light-harvesting systems(LHSs) have drawn increasing research interest in recent times due to the energy crisis worldwide. Concurrently, macrocycle-based host–vip interactions have played an important role in the development of supramolecular chemistry. In recent years, studies towards artificial LHSs driven by macrocycle-based host–vip interactions are gradually being disclosed. In this mini-review, we briefly introduce the burgeoning progress of artificial LHSs driven by host–vip interactions. We believe that an increasing number of reports of artificial LHSs driven by host–vip interactions will appear in the near future and will provide a viable alternative for the future production of renewable energy.展开更多
Based on the features of the design and assembly of rnodular fixtures, a new design system which combines intelligent selection of elements and interactive assembly is presented.Using the fixture design datum, the sys...Based on the features of the design and assembly of rnodular fixtures, a new design system which combines intelligent selection of elements and interactive assembly is presented.Using the fixture design datum, the system can automatically select elements,and can interactively assemble together these elements based on AutoCAD. An example is given to illustrate it.展开更多
The existing research of supply coordination under uncertain delivery time mainly focuses on the collaboration between the supplier and the manufacturer, which aim at minimizing the total cost of each side and finding...The existing research of supply coordination under uncertain delivery time mainly focuses on the collaboration between the supplier and the manufacturer, which aim at minimizing the total cost of each side and finding comparative optimal solutions under decentralized decision. In the supply coordination, the collaboration between suppliers in assembly system is usually not considered. As a result, the manufacturer’s production is often delayed due to mismatching delivery of components between suppliers. Therefore, to ensure supply coordination in assembly system, collaboration between suppliers should be taken into consideration. In this paper, an assembly system with two suppliers and one manufacturer under uncertain delivery time is considered. The model is established and optimal solution is given under decentralized decision. Furthermore, the cost functions of two suppliers are both convex, and a unique Nash equilibrium exists between two suppliers. Then the optimal decision under supply coordination is analyzed, which is regarded as a benchmark for supply coordination. Additionally, the total cost of the assembly system is jointly convex in agreed delivery time. To achieve supply coordination a bonus policy is explored in the assembly system under uncertain delivery time, and the total cost under bonus policy must be lower than under decentralized decision. Finally the numerical and sensitivity analysis shows the cost of assembly system under bonus policy equals that under supply coordination, and the cost of each side in assembly system under bonus policy is lower compared to that under decentralized decision. The proposed research minimizes the total cost of each side with bonus policy in assembly system, ensures the supply coordination between suppliers and the manufacturer, and improves the competiveness of the whole supply chain.展开更多
In this paper we provide a novel approach for breaking a significant class of block ciphers, the so-called SPN ciphers, using the process of gene assembly in ciliates. Our proposed scheme utilizes, for the first time,...In this paper we provide a novel approach for breaking a significant class of block ciphers, the so-called SPN ciphers, using the process of gene assembly in ciliates. Our proposed scheme utilizes, for the first time, the Turing-powerful potential of gene assembly procedure of ciliated protozoa into the real world computations and has a fewer number of steps than the other proposed schemes to break a cipher. We elaborate notions of formal language theory based on AIR systems, which can be thought of as a modified version of intramolecular scheme to model the ciliate bio-operations, for construction of building blocks necessary for breaking the cipher, and based on these nature-inspired constructions which are as powerful as Turing machines, we propose a theoretical approach for breaking SPN ciphers. Then, we simulate our proposed plan for breaking these ciphers on a sample block cipher based on this structure. Our results show that the proposed scheme has 51.5 percent improvement over the best previously proposed nature-inspired scheme for breaking a cipher.展开更多
Swarm intelligence embodied by many species such as ants and bees has inspired scholars in swarm robotic researches. This paper presents a novel autonomous self-assembly distributed swarm flying robot-DSFR, which can ...Swarm intelligence embodied by many species such as ants and bees has inspired scholars in swarm robotic researches. This paper presents a novel autonomous self-assembly distributed swarm flying robot-DSFR, which can drive on the ground, autonomously accomplish self-assembly and then fly in the air coordinately. Mechanical and electrical designs of a DSFR module, as well as the kinematics and dynamics analysis, are specifically investigated. Meanwhile, this paper brings forward a generalized adjacency matrix to describe configurations of DSFR structures. Also, the distributed flight control model is established for vertical taking-off and horizontal hovering, which can be applied to control of DSFR systems with arbitrary configurations. Finally, some experiments are carried out to testify and validate the DSFR design, the autonomous self-assembly strategy and the distributed flight control laws.展开更多
The growing global competition compels organizations to use many productivity improvement techniques. In this direction, assembly line balancing helps an organization to design its assembly line such that its balancin...The growing global competition compels organizations to use many productivity improvement techniques. In this direction, assembly line balancing helps an organization to design its assembly line such that its balancing efficiency is maximized. If the organization assembles more than one model in the same line, then the objective is to maximize the average balancing efficiency of the models of the mixed model assembly line balancing problem. Maximization of average balancing efficiency of the models along with minimization of makespan of sequencing models forms a multi-objective function. This is a realistic objective function which combines the balancing efficiency and makespan. This assembly line balancing problem with multi-objective comes under combinatorial category. Hence, development of meta-heuristic is inevitable. In this paper, an attempt has been made to develop three genetic algorithms for the mixed model assembly line balancing problem such that the average balancing efficiency of the model is maximized and the makespan of sequencing the models is minimized. Finally, these three algorithms and another algorithm in literature modified to solve the mixed-model assembly line balancing problem are compared in terms of the stated multi-objective function using a randomly generated set of problems through a complete factorial experiment.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51290293,51520105006)National Key R&D Program of China(Grant No.2017YFC0110401)
文摘Soft cable-driven systems have been employed in many assembled mechanisms, such as industrial robots, parallel kinematic mechanism machines, medical devices, and humaniform hands. A pre-stretching process is necessary to guarantee the quality of cable-driven systems during the assembly process. However, the stress relaxation of cables becomes a critical concern during long-term operation. This study investigates the effects of non-uniform deformation and long-term stress relaxation of the driven cables owing to moving parts in the system. A simple closed-loop cable-driven system is built and an alternating load is applied to it to replicate the operation of transmission cables. Under different experimental conditions, the cable tension is recorded and the boundary data are selected to be curve-fitted. Based on the fitted results, a formula is presented to estimate the stress relaxation of cables to evaluate the assembly performance. Further experimental results show that the stress relaxation is mainly caused by cable creep and the assembly procedure. To remove the influence of the assembly procedure, a modified pre-stretching assembly method based on the stress relaxation theory is proposed and verification experiments are performed. Finally, the assembly performance is optimized using a cable-driven surgical robot as an example. This paper proposes a dual stretching method instead of the pre-stretching method to assemble the cable-driven system to improve its performance and prolong its service life.
文摘Today＇s production systems are demanded to exhibit an increased flexibility and mutability in order to deal with dynamically changing conditions, objectives and an increasing number of product variants within industrial turbulent environments. Flexible automated systems are requested in order to improve dynamic production efficiency, e.g. robot-based hardware and PC-based controllers, but these usually induce a significantly higher production complexity, whereby the efforts for planning and programming, but also setups and reconfiguration, expand. In this paper a definition and some concepts of self-optimizing assembly systems are presented to describe possible ways to reduce the planning efforts in complex production systems. The concept of self-optimization in assembly systems will be derived from a theoretical approach and will be transferred to a specific application scenario---the automated assembly of a miniaturized solid state laser--where the challenges of unpredictable influences from e.g. component tolerances can be overcome by the help of self-optimization.
文摘The failure modes and effects analysis （FMEA） is widely applied in manufacturing industries in various phases of the product life cycle to evaluate the system, its design and processes for failures that can occur. The FMEA team often demonstrates different opinions and these different types of opinions are very difficult to incorporate into the FMEA by the traditional risk priority number model. In this paper, for each of the Occurrence, Severity and Detectivity parameters a fuzzy set is defined and the opinion of each FMEA team members is considered. These opinions are considered simultaneously with weights that are given to each individual based on their skills and experience levels. In addition, the opinion of the costumer is considered for each of the FMEA parameters. Then, the Risk Priority Numbers （RPN） is calculated using a Multi Input Single Output （MISO） fuzzy expert system. The proposed model is applied for prioritizing the failures of Peugeot 206 Engine assembly line in IKCo （Iran Khodro Company）.
基金supported by the National Natural Science Foundation of China(21031006)NSFC-DFG joint fund(TRR 61)the National Basic Research 973 Program of China(2011CB932302 and 2012CB932900)
文摘Porphyrins are abundant in nature. They have been frequently employed as building blocks in the construction of nanoarchitectures and functional supramolecular systems. Recently, a series of novel porphyrin molecules including small molecules and polymers have been originally designed and synthesized with the aim of producing nanostructures with controllable-growth and materials with high-performance. Literature coverage is through 2004-2012. This review gives a full summary of related studies in our group.
基金supported by National Important Project on Science&Technology of China(Grant No.2009ZX04014-031)Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.200803350031)+2 种基金Zhejiang Provincial Natural Science Foundation of China(Grant No.Y1080358)Research Fund of Zhejiang Educational Committee of China(Grant No.Y200909651)PACMAN Project within the French National Research Agency
文摘Nano assembly and manipulation technologies are the basis for nano-electro-mechanical systems（NEMS）. Atomic force microscope（AFM） is widely used to manipulate nanotubes to assemble NEMS. Manipulating nanotubes with AFM is a challenging and difficult task. One of the major reasons is the deficiency of visual information during the manipulation process. To address these difficulties, this research aims to put forward novel virtual tools and assembly strategies to improve the efficiency, accuracy and ease of the assembly process of NEMS. This paper begins by the discussion of the principles and implementation of a virtual nano-assembly simulator, which serves as a benchmark to test the proposed NEMS assembly techniques and virtual tools. Then, a general framework of nanotube-based NEMS assembly is proposed. Several nano-assembly strategies and virtual tools, such as automated path planning for NEMS assembly, a four-step scheme of nanotube manipulation, virtual fixtures for assembly finalization and safe manipulation, are introduced. These virtual tools and methods are experimented for justification. An assembly task of moderate complexity was performed in our virtual nano-assembly simulator with and without the help of the proposed toolkit. Experimental results suggest that the proposed methods tend to greatly enhance the efficiency and accuracy of nanotube-based NEMS assembly. In general, the proposed virtual reality toolkit not only ensures the safety, but also enhances the accuracy and efficiency of the assembly of nanotube-based NEMS.
基金the National Natural Science Foundation of China(No.71071115)the National High Technology Research and Development Program (863) of China(No.2009AA043000)
文摘To solve the sequencing problem in mixed-model flexible assembly lines (MMFALs) with variable launching intervals, a mathematical model aiming to minimize the cost of utility and idle times is developed. To obtain high-quality sequences, an advanced scatter search (ASS) algorithm is proposed. A heuristic approach, i.e. launching intervals between products algorithm (LIBPA), is incorporated into the ASS algorithm to solve the launching interval problem for each sequence. Numerical experiments with different scales are conducted to compare the performance of ASS with genetic algorithm (GA). In addition, we compare the cost of variable launching intervals approach with fixed launching intervals approach. The results indicate that the ASS is efficient and effective, and considering variable launching intervals in mixed-model assembly lines (MMALs) sequencing problem can improve the performance of the line.
文摘The growing global competition compels manufacturing organizations to engage themselves in all productivity improvement activities. In this direction, the consideration of mixed-model assembly line balancing problem and implementing in industries plays a major role in improving organizational productivity. In this paper, the mixed model assembly line balancing problem with deterministic task times is considered. The authors made an attempt to develop a genetic algorithm for realistic design of the mixed-model assembly line balancing problem. The design is made using the originnal task times of the models, which is a realistic approach. Then, it is compared with the generally perceived design of the mixed-model assembly line balancing problem.
文摘Presents a multi robot cooperative assembly system (MRCAS) which is composed of an organizer computer, three industrial robots, PUMA 562 mounted on an omni directional vehicle, PUMA 760 and Adept I and organized into a hierarchical structure with the cooperation organization on the top and the coordination motion at the bottom to solve the main problem of coordination and cooperation among robots, and concludes with experimental results that MRCAS is reconfigurable and adaptable as the mission changes.
文摘Mixed-model U-shaped assembly line balancing problems (MMUALBP) is known to be NP-hard resulting in it being nearly impossible to obtain an optimal solution for practical problems with deterministic algorithms. This paper pre-sents a new evolutionary method called combinatorial optimisation with coincidence algorithm (COIN) being applied to Type I problems of MMUALBP in a just-in-time production system. Three objectives are simultaneously considered;minimum number workstations, minimum work relatedness, and minimum workload smoothness. The variances of COIN are also proposed, i.e. CNSGA II, and COIN-MA. COIN and its variances are tested against a well-known algo-rithm namely non-dominated sorting genetic algorithm II (NSGA II) and MNSGA II (a memetic version of NSGA II). Experimental results showed that COIN outperformed NSGA II. In addition, although COIN-MA uses a marginal CPU time than CNSGA II, its other performances are dominated.
文摘In the SILER （Seismic-Initiated events risk mitigation in LEad-cooled Reactors） Project, it is interesting to apply seismic isolation technology for the reactor assembly of the fixed base reactor building for ADS （Acceleration Driven System） heavy liquid reactor MYRRHA （Multipurpose Hybrid Research Reactor for High-Tech Application） which contains the most critical safety related components, such as reactor vessel, safe shutdown and control rod mechanisms, primary heat exchangers, primary pumps, spoliation target assembly and fuel assemblies, etc. The purpose of this paper is to investigate the possibility of an application of a partial seismic isolation to the safety critical components only, here, the reactor assembly. This paper presents the preliminary analysis results of the isolated reactor assembly and compares these with those of seismic isolated ADS reactor building. The analysis results show the reduction of the seismic acceleration response but the increase of the relative displacement for the reactor assembly. Some safety issues, especially, coolant＇s incapable covering the reactor core make difficult to apply for the partial seismic isolation of the ADS reactor assembly due to large relative displacement occurring the partial isolation system. Further study on the partial seismic isolation application of the critical safety components are also discussed.
文摘This paper gives brief introduction to the production management and control system (PMCS) for 10th assembly workshop under Xi’ an Aircraft Company (XAC)--CIMS. Its user requirements 9 structure, ftinctions, and implementation are described. It is showed that the development problems of PMCS can be further reduced to a development methodology for Chinese enterprises, which will make them competitive.
基金Project sponseored by special scientific research foundation for doctoral subjects
文摘To fulfil the need of development of offshore oil floating production system, the performance of turret assembly in an inboard turret mooring system has been investigated in the paper. By means of systematic evaluation, the optimal structure of the turret for single-point mooring systems has been determined. Through model tests of a turret mooring system, several groups of data such as forces, moments and displacements under different environmental conditions have been obtained. Stresses and strains of the turret structure have been calculated by means of the finite element method corresponding to the situation in the model experiment. The study shows that the selected turret structure and the designed turret assembly are technically feasible.
文摘【目的】构建方便快捷的植物表达载体。【方法】应用Isothermal in vitro recombination system or “Gibson Assem-bly”方法设计包含片段间20～25 bp互补重叠序列的引物，通过PCR扩增出带有首尾重叠的目的DNA片段，可将1个或多个片段和线性化的载体一步组装成表达载体。【结果和结论】利用该方法快速构建了多个水稻基因的全长以及部分缺失编码区表达载体。此外，还通过对Gibson Assembly连接产物进行PCR扩增后再连接到载体，提高多DNA片段组装的效率。本方法不受目的片段内部限制性酶切位点的限制，可广泛应用于各种载体的构建。
基金the National Natural Science Foundation of China (Nos. 21272093 and 51473061)the Fundamental Research Funds for the Central Universities (No. JCKY-QKJC05) for financial support
文摘In recent years, cancer has become the number two cause of death around the world, and scientists have exploited various treatment maps. Calixarenes, with diversified features, have been widely applied into drug delivery systems, which can respond to multi-stimuli and exhibit excellent performance. In this mini-review, we summarize the recent advances on controlled drug delivery systems based on calixarenes, in the form of inclusion complexes, amphiphilic self-assembly nanocarriers including micelles, hydrogels, vesicles and liposomes, and supramolecular nanovalves on mesoporous silica nanomaterials.
基金financial support of the National Natural Science Foundation of China (No. 21702020)
文摘Artificial light-harvesting systems(LHSs) have drawn increasing research interest in recent times due to the energy crisis worldwide. Concurrently, macrocycle-based host–vip interactions have played an important role in the development of supramolecular chemistry. In recent years, studies towards artificial LHSs driven by macrocycle-based host–vip interactions are gradually being disclosed. In this mini-review, we briefly introduce the burgeoning progress of artificial LHSs driven by host–vip interactions. We believe that an increasing number of reports of artificial LHSs driven by host–vip interactions will appear in the near future and will provide a viable alternative for the future production of renewable energy.
文摘Based on the features of the design and assembly of rnodular fixtures, a new design system which combines intelligent selection of elements and interactive assembly is presented.Using the fixture design datum, the system can automatically select elements,and can interactively assemble together these elements based on AutoCAD. An example is given to illustrate it.
基金supported by National Natural Science Foundation of China(Grant No. 71102174)Beijing Municipal Natural Science Foundation of China(Grant Nos. 9123028, 9102016)+3 种基金Specialized Research Fund for Doctoral Program of Higher Education of China(Grant No. 20111101120019)Beijing Municipal Philosophy and Social Science Foundation of China(Grant No. 11JGC106)Program for New Century Excellent Talents in University of China(Grant Nos. NCET-10-0048,NCET-10-0043)Excellent Young Teacher in Beijing Institute of Technology of China(Grant No. 2010YC1307)
文摘The existing research of supply coordination under uncertain delivery time mainly focuses on the collaboration between the supplier and the manufacturer, which aim at minimizing the total cost of each side and finding comparative optimal solutions under decentralized decision. In the supply coordination, the collaboration between suppliers in assembly system is usually not considered. As a result, the manufacturer’s production is often delayed due to mismatching delivery of components between suppliers. Therefore, to ensure supply coordination in assembly system, collaboration between suppliers should be taken into consideration. In this paper, an assembly system with two suppliers and one manufacturer under uncertain delivery time is considered. The model is established and optimal solution is given under decentralized decision. Furthermore, the cost functions of two suppliers are both convex, and a unique Nash equilibrium exists between two suppliers. Then the optimal decision under supply coordination is analyzed, which is regarded as a benchmark for supply coordination. Additionally, the total cost of the assembly system is jointly convex in agreed delivery time. To achieve supply coordination a bonus policy is explored in the assembly system under uncertain delivery time, and the total cost under bonus policy must be lower than under decentralized decision. Finally the numerical and sensitivity analysis shows the cost of assembly system under bonus policy equals that under supply coordination, and the cost of each side in assembly system under bonus policy is lower compared to that under decentralized decision. The proposed research minimizes the total cost of each side with bonus policy in assembly system, ensures the supply coordination between suppliers and the manufacturer, and improves the competiveness of the whole supply chain.
文摘In this paper we provide a novel approach for breaking a significant class of block ciphers, the so-called SPN ciphers, using the process of gene assembly in ciliates. Our proposed scheme utilizes, for the first time, the Turing-powerful potential of gene assembly procedure of ciliated protozoa into the real world computations and has a fewer number of steps than the other proposed schemes to break a cipher. We elaborate notions of formal language theory based on AIR systems, which can be thought of as a modified version of intramolecular scheme to model the ciliate bio-operations, for construction of building blocks necessary for breaking the cipher, and based on these nature-inspired constructions which are as powerful as Turing machines, we propose a theoretical approach for breaking SPN ciphers. Then, we simulate our proposed plan for breaking these ciphers on a sample block cipher based on this structure. Our results show that the proposed scheme has 51.5 percent improvement over the best previously proposed nature-inspired scheme for breaking a cipher.
基金the National High-tech Research and Development Program of China(''863''Program)(No.2012AA041402)National Natural Science Foundation of China(Nos.61175079and51105012)Fundamental Research Funds for the Central Universities (No.YWF-11-02-215)
文摘Swarm intelligence embodied by many species such as ants and bees has inspired scholars in swarm robotic researches. This paper presents a novel autonomous self-assembly distributed swarm flying robot-DSFR, which can drive on the ground, autonomously accomplish self-assembly and then fly in the air coordinately. Mechanical and electrical designs of a DSFR module, as well as the kinematics and dynamics analysis, are specifically investigated. Meanwhile, this paper brings forward a generalized adjacency matrix to describe configurations of DSFR structures. Also, the distributed flight control model is established for vertical taking-off and horizontal hovering, which can be applied to control of DSFR systems with arbitrary configurations. Finally, some experiments are carried out to testify and validate the DSFR design, the autonomous self-assembly strategy and the distributed flight control laws.
文摘The growing global competition compels organizations to use many productivity improvement techniques. In this direction, assembly line balancing helps an organization to design its assembly line such that its balancing efficiency is maximized. If the organization assembles more than one model in the same line, then the objective is to maximize the average balancing efficiency of the models of the mixed model assembly line balancing problem. Maximization of average balancing efficiency of the models along with minimization of makespan of sequencing models forms a multi-objective function. This is a realistic objective function which combines the balancing efficiency and makespan. This assembly line balancing problem with multi-objective comes under combinatorial category. Hence, development of meta-heuristic is inevitable. In this paper, an attempt has been made to develop three genetic algorithms for the mixed model assembly line balancing problem such that the average balancing efficiency of the model is maximized and the makespan of sequencing the models is minimized. Finally, these three algorithms and another algorithm in literature modified to solve the mixed-model assembly line balancing problem are compared in terms of the stated multi-objective function using a randomly generated set of problems through a complete factorial experiment.
