The telecommunications industry has been undergoing tremendous technological changes, and owning to continuous technological advancement, it has maintained sustained prosperity and development. In this paper, the inte...The telecommunications industry has been undergoing tremendous technological changes, and owning to continuous technological advancement, it has maintained sustained prosperity and development. In this paper, the interplay between technology, market and government in telecommunications is discussed briefly, and then we introduce technology and government into the traditional SCP(Structure – Conduct – Performance) paradigm to develop an industry analysis framework called TGM(SCP)(Technology – Government – Market(Structure – Conduct – Performance)). Based on this framework, we present the spiral coevolution model which elaborates on the interaction mechanism of technological innovation with government regulation and market dynamics from the perspective of industry evolution. Our study indicates that the development of the telecommunications industry is the result of the coevolution of technology, government regulation and market forces, and among the three actors, technology is the fundamental driving force. Relative to the "invisible hand"(market) and "visible hand"(government), we conceptualize technology as the "third hand", which fundamentally drives the development of telecommunications industry in coordination with the other two hands. We also provide several policy implications regarding these findings.展开更多
In this paper, progresses of color maintenance, also known as color shift, in solid-state lighting(SSL) systems are thoroughly reviewed. First, color shift is introduced and a few examples are given from different rea...In this paper, progresses of color maintenance, also known as color shift, in solid-state lighting(SSL) systems are thoroughly reviewed. First, color shift is introduced and a few examples are given from different real-life industrial conditions. Different degradation mechanisms in different parts of the system are also explained. Different materials used as lenses/encapsulants in light-emitting diode(LED)-based products are introduced and their contributions to color shift are discussed. Efforts put into standardization, characterizing, and predicting lumen maintenance are also briefly reviewed in this paper.展开更多
The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, more...The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, moreover, organic solvents are used in various industrial processes. Organic solvents used in different industrial processes may be associated with hepatotoxicity. Several factors contribute to liver toxicity; among these are: species differences, nutritional condition, genetic factors, interaction with medications in use, alcohol abuse and interaction, and age. This review addresses the mechanisms of hepatotoxicity. The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are: inflammation, dysfunction of cytochrome P450, mitochondrial dysfunction and oxidative stress. The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work.展开更多
With the Pearson Correlation Coefficient measurement method, this paper studies the correlation between the various elements influencing the financial competitiveness of the fast fashion enterprieses and the long-term...With the Pearson Correlation Coefficient measurement method, this paper studies the correlation between the various elements influencing the financial competitiveness of the fast fashion enterprieses and the long-term financial stability, which shows that the financial resilience has the biggest correlation with the long-term financial stability, which is followed in sequence by financial management capacity, financial resources capacity, financial performance capacity, and financial activity capacity. This is due to the fact that such factors as financial solvency, financial operations, profitability, growth capacity and the ability to generate cash exert effect upon the long-term stability of the financial competitiveness.展开更多
This work aims to establish a suitable numerical simulation model for hybrid laser-electric arc heat source welding of dissimilar Mg alloys between AZ31 and AZ80. Based on the energy conservation law and Fourier’s la...This work aims to establish a suitable numerical simulation model for hybrid laser-electric arc heat source welding of dissimilar Mg alloys between AZ31 and AZ80. Based on the energy conservation law and Fourier’s law of heat conduction, the differential equations of the three-dimensional temperature field for nonlinear transient heat conduction are built. According to the analysis of nonlinear transient heat transfer, the equations representing initial conditions and boundary conditions are obtained. The “double ellipsoidal heat source + 3D Gaussian heat source”combination was chosen to construct the laser-electric arc hybrid heat source. The weld bead morphologies and the distribution of temperature, stress, displacement and plastic strains are numerically simulated. The actual welding experiments were performed by a hybrid laser-electric arc welding machine. The interaction mechanism between laser and electric arc in the hybrid welding of Mg alloys is discussed in detail. The hybrid heat source can promote the absorption of laser energy and electric arc in the molten pool, resulting in more uniform energy distribution in the molten pool and the corresponding improvement of welding parameters. This work can provide theoretical guidance and data supports for the optimization of the hybrid laser-electric arc welding processes for Mg alloys.展开更多
By employing numerical modeling, similar material simulation and comprehen-sive field observation, investigations were made and patterns were obtained governing surrounding-rock stress distribution and strata behavior...By employing numerical modeling, similar material simulation and comprehen-sive field observation, investigations were made and patterns were obtained governing surrounding-rock stress distribution and strata behaviors. It shows that patterns governing displacement of FMC roadway surrounding rocks and those governing deformation of supports are basically the same along the strike, but the displacements vary greatly. The front stresses affect greater areas than the lateral stresses and their limit widths of equilib-rium zones and K are almost similar. The stress transmits very deep. Our findings offer scientific basis on which to determine parameters for coal pillar retaining and for roadway out-laying, thus increasing the recovery ratio and improving the maintenance of roadway.展开更多
In order to effectively control the random tasks submitted and executed in grid workflow,a grid workflow model based on hybrid petri-net is presented. This model is composed of random petri-net,colored petri-net and g...In order to effectively control the random tasks submitted and executed in grid workflow,a grid workflow model based on hybrid petri-net is presented. This model is composed of random petri-net,colored petri-net and general petri-net. Therein random petri-net declares the relationship between the number of grid users' random tasks and the size of service window and computes the server intensity of grid system. Colored petri-net sets different color for places with grid services and provides the valid interfaces for grid resource allocation and task scheduling. The experiment indicated that the model presented in this letter could compute the valve between the number of users' random tasks and the size of grid service window in grid workflow management system.展开更多
"Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that in..."Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.展开更多
Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill & simulation based hybrid control architecture (S2BHCA) as the controller's design refe...Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill & simulation based hybrid control architecture (S2BHCA) as the controller's design reference was proposed. It is a multi-robot cooperation oriented intelligent control architecture based on hybrid ideas. The S2 BHCA attempts to incorporate the virtues of the reactive controller and of the deliberative controller by introducing the concept of the "skill". The additional online task simulation ability for cooperation is supported, too. As an application, a multiple AUV control system was developed with three "skills" for the MCM mission including two different cooperative tasks. The simulation and the sea trials show that simple task expression, fast reaction and better cooperation support can be achieved by realizing the AUV controller based on the S2 BHCA.展开更多
The design and development Web 2.0-based education management system will satisfy with the school education management of informationization, scientific and modernized request, the auxiliary education superintendent c...The design and development Web 2.0-based education management system will satisfy with the school education management of informationization, scientific and modernized request, the auxiliary education superintendent carries on the correct decision-making, enhance the education management working efficiency. This system has used the quite mature development technology at present, the function of realizes is more perfect, usable; The man-machine interaction is friendly and operate easily. Its application, enhanced the administrator and teacher's working efficiency greatly, reduces the working strength, simultaneously has also provided the better education condition for the student. With the rapid development of network,, education management system will be more widespread in the education of education application, it will create a new situation of the education management, bring a brighter prospect of the application.展开更多
The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments. The result shows that there are different inhibition types at differ-ent lead contents. Higher lead ...The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments. The result shows that there are different inhibition types at differ-ent lead contents. Higher lead content leads to more inhibition granular sludge, and at the same time, the time of gas recovery is different. Lower lead content per microorganism results in sooner sludge recovery. Microorganisms have a good ability to resist lead toxicity.展开更多
Based on the characteristics of the ripping of rock, the simulated conditions that would be satisfied by the prototype ripping and the model ripping have been derived in this paper. In order to .nanufacture the satisf...Based on the characteristics of the ripping of rock, the simulated conditions that would be satisfied by the prototype ripping and the model ripping have been derived in this paper. In order to .nanufacture the satisfying equivalent materials for the model ripping, a new method has been set up, and the materials, which can simulate the prototype rock "Hawkesbury sandstone", have been made by using the methed.展开更多
The noise level of coal face by full-mechanized coal winning technology was measured in a coal mine. And then it was analyzed and evaluated using environment science, ergonomics and fussy mathematics analysis. Basis o...The noise level of coal face by full-mechanized coal winning technology was measured in a coal mine. And then it was analyzed and evaluated using environment science, ergonomics and fussy mathematics analysis. Basis of the statistics and analysis of the measured noise level some measures, such as applying the new materials and improving the construction of the equipment, were carried out. The resuts show that they can reduce the noise level, improve the working environment and enhance the work efficiency.展开更多
Over the course of the past 70 years, the objectives of CA (cellular automata) research shifted from speculative and illustrative purposes without immediate goals outside of given implementations to the more utilita...Over the course of the past 70 years, the objectives of CA (cellular automata) research shifted from speculative and illustrative purposes without immediate goals outside of given implementations to the more utilitarian scientific and engineering objectives of simulating, controlling and predicting other phenomena. Looking back at our own 10-year history of CA related work, however, we recognize a generally inverse tendency from utilitarian objectives to finding more illustrative and speculative value. In this paper, we present a reflection on our own body of CA work, and we discuss the qualities of the various outcomes and insights we gained from a second-order cybernetic perspective. We argue that much of our own CA work may best be understood as creating machines for showing and for repurposing that allow their observers to gain new (second-order cybernetic) ways of seeing from interacting with them.展开更多
XY table automated assembly machines ensure time saving and quality improving in the electronics industry. Recently, due to the need of higher operation speeds and lighter machines in PCB (Printed Circuit Board) ass...XY table automated assembly machines ensure time saving and quality improving in the electronics industry. Recently, due to the need of higher operation speeds and lighter machines in PCB (Printed Circuit Board) assembly, a challenging problem has arisen which is the table positioning vibration. The high speed with the machine flexibility, make the positioning vibration inevitable although the inner control. The positioning vibration is to be reduced otherwise the machine becomes useless. Firstly, the machine is modeled, the positioning vibration is formulated, and then analyzed. Secondly, using the analysis, three direct control methods are identified to decrease the positioning vibration, they are based on the kinematics, dynamics, and operation of the machine. Thirdly, the methods are examined numerically to evaluate their efficiency. Lastly, the identified methods are discussed to conclude on their application. The results are a real contribution in the vibration control of XY table automated assembly machines, which is classified as industrial knowhow.展开更多
The retirement age policy adjustment is again sharing the cost of the aging process, incentives to delay retirement life expectancy means that workers work longer. Developed by the elastic mechanism into retirement sy...The retirement age policy adjustment is again sharing the cost of the aging process, incentives to delay retirement life expectancy means that workers work longer. Developed by the elastic mechanism into retirement system framework, improve the flexibility of the retirement system, in curbing early retirement incentives to delay retirement, improve the elderly labor force participation rate, and achieved some success. The reform of the retirement system gradually into public view. To adapt to China's national conditions for the establishment of flexible retirement mechanism, western countries need to discuss flexible retirement system, in-depth analysis of the establishment of the special constraints flexible retirement mechanism, good theoretical advance preparation for retirement Mechanism.展开更多
In this work, the stability of an endoreversible Curzon-Ahlbom engine is analyzed, using Van der Waals gas as a working substance and the corresponding efficiency for this engine working at temperatures withinthe maxi...In this work, the stability of an endoreversible Curzon-Ahlbom engine is analyzed, using Van der Waals gas as a working substance and the corresponding efficiency for this engine working at temperatures withinthe maximum ecological regime. By mean s of a local stability analysis we find that a critical point of an almost linear system is stable andanalytically expressed in eigenvalues. After an arbitrarily small perturbation, the system state exponentially decays to a critical point, with either of two characteristic relaxation times, which are a function of the thermal conductance (a), heat capacity (C) and T=T2/T1. The behavior of relaxation times and solution of the systems are qualitatively shown by sketching its phase portrait, which results susceptible to operating regimes, i.e., the eigenvectors in the maximum ecological regime have a clockwise rotation with respect to the eigenvectors in the regime of maximumpower. Finally, it has to observe that afterto λvw = 1, approximation,ηVWE=4^-3ηC is obtained, where ηVWE is the Van der Waals efficiency atrnaximum ecological regime and r/c is Carnot's efficiency. Finally, it discussed the local stability and steady state of the energetic properties of the endoreversible engine.展开更多
In this paper, design and fabrication of a commemorative plaque are described and presented. The plaque was fabricated to honour the memory of the 14 women massacred at L'Ecole Polytechnique in Montreal. This plaque ...In this paper, design and fabrication of a commemorative plaque are described and presented. The plaque was fabricated to honour the memory of the 14 women massacred at L'Ecole Polytechnique in Montreal. This plaque is the result of a project partnership between the Faculties of Engineering and Fine Arts, and was sponsored by the Office of the Vice-President Academic and Provost. An art design was selected through a contest coordinated by the Visual Arts Departmment. The selected art design was then turned over to the Mechanical Engineering Department to be converted to a 3-dimensional (3D) solid model and then eventually fabricated on a computer numerical control (CNC) milling machine. The fabricated plaque was unveiled during the December 2010 Memorial event at UVic.展开更多
This paper presents a bioelectrochemical model for the activation of action potentials on sarcolemma and variation of Ca2+ concentration in sarcomeres of skeletal muscle fibers.The control mechanism of muscle contract...This paper presents a bioelectrochemical model for the activation of action potentials on sarcolemma and variation of Ca2+ concentration in sarcomeres of skeletal muscle fibers.The control mechanism of muscle contraction generated by collective motion of molecular motors is elucidated from the perspective of variable-frequency regulation,and action potential with variable frequency is proposed as the control signal to directly regulate Ca2+ concentration and indirectly control isometric tension.Furthermore,the transfer function between stimulation frequency and Ca2+ concentration is deduced,and the frequency domain properties of muscle contraction are analyzed.Moreover the conception of "electro-muscular time constant" is defined to denote the minimum delay time from electric stimulation to muscle contraction.Finally,the experimental research aiming at the relation between tension and stimulation frequency of action potential is implemented to verify the proposed variable-frequency control mechanism,whose effectiveness is proved by good consistence between experimental and theoretical results.展开更多
基金supported by Major Program of the National Social Science Foundation of China under Grant No.15ZDB154National Basic Research Program of China (973 Program) under Grant No. 2012CB315805
文摘The telecommunications industry has been undergoing tremendous technological changes, and owning to continuous technological advancement, it has maintained sustained prosperity and development. In this paper, the interplay between technology, market and government in telecommunications is discussed briefly, and then we introduce technology and government into the traditional SCP(Structure – Conduct – Performance) paradigm to develop an industry analysis framework called TGM(SCP)(Technology – Government – Market(Structure – Conduct – Performance)). Based on this framework, we present the spiral coevolution model which elaborates on the interaction mechanism of technological innovation with government regulation and market dynamics from the perspective of industry evolution. Our study indicates that the development of the telecommunications industry is the result of the coevolution of technology, government regulation and market forces, and among the three actors, technology is the fundamental driving force. Relative to the "invisible hand"(market) and "visible hand"(government), we conceptualize technology as the "third hand", which fundamentally drives the development of telecommunications industry in coordination with the other two hands. We also provide several policy implications regarding these findings.
基金project (M71.9.10380) in the framework of the Research Program of the Materials Innovation Institute M2i (www.m2i.nl)
文摘In this paper, progresses of color maintenance, also known as color shift, in solid-state lighting(SSL) systems are thoroughly reviewed. First, color shift is introduced and a few examples are given from different real-life industrial conditions. Different degradation mechanisms in different parts of the system are also explained. Different materials used as lenses/encapsulants in light-emitting diode(LED)-based products are introduced and their contributions to color shift are discussed. Efforts put into standardization, characterizing, and predicting lumen maintenance are also briefly reviewed in this paper.
文摘The liver is the main organ responsible for the metabolism of drugs and toxic chemicals, and so is the primary target organ for many organic solvents. Work activities with hepatotoxins exposures are numerous and, moreover, organic solvents are used in various industrial processes. Organic solvents used in different industrial processes may be associated with hepatotoxicity. Several factors contribute to liver toxicity; among these are: species differences, nutritional condition, genetic factors, interaction with medications in use, alcohol abuse and interaction, and age. This review addresses the mechanisms of hepatotoxicity. The main pathogenic mechanisms responsible for functional and organic damage caused by solvents are: inflammation, dysfunction of cytochrome P450, mitochondrial dysfunction and oxidative stress. The health impact of exposure to solvents in the workplace remains an interesting and worrying question for professional health work.
文摘With the Pearson Correlation Coefficient measurement method, this paper studies the correlation between the various elements influencing the financial competitiveness of the fast fashion enterprieses and the long-term financial stability, which shows that the financial resilience has the biggest correlation with the long-term financial stability, which is followed in sequence by financial management capacity, financial resources capacity, financial performance capacity, and financial activity capacity. This is due to the fact that such factors as financial solvency, financial operations, profitability, growth capacity and the ability to generate cash exert effect upon the long-term stability of the financial competitiveness.
基金Project(52004154) supported by the National Natural Science Foundation of ChinaProject(ZR2020QE002) supported by the Shandong Provincial Natural Science Foundation,ChinaProject(6142005190208) supported by the National Key Laboratory Foundation of China。
文摘This work aims to establish a suitable numerical simulation model for hybrid laser-electric arc heat source welding of dissimilar Mg alloys between AZ31 and AZ80. Based on the energy conservation law and Fourier’s law of heat conduction, the differential equations of the three-dimensional temperature field for nonlinear transient heat conduction are built. According to the analysis of nonlinear transient heat transfer, the equations representing initial conditions and boundary conditions are obtained. The “double ellipsoidal heat source + 3D Gaussian heat source”combination was chosen to construct the laser-electric arc hybrid heat source. The weld bead morphologies and the distribution of temperature, stress, displacement and plastic strains are numerically simulated. The actual welding experiments were performed by a hybrid laser-electric arc welding machine. The interaction mechanism between laser and electric arc in the hybrid welding of Mg alloys is discussed in detail. The hybrid heat source can promote the absorption of laser energy and electric arc in the molten pool, resulting in more uniform energy distribution in the molten pool and the corresponding improvement of welding parameters. This work can provide theoretical guidance and data supports for the optimization of the hybrid laser-electric arc welding processes for Mg alloys.
基金Supported by the Natural Sciences of Anhui Provincial Education Division(2002kj286ZD,01044403)
文摘By employing numerical modeling, similar material simulation and comprehen-sive field observation, investigations were made and patterns were obtained governing surrounding-rock stress distribution and strata behaviors. It shows that patterns governing displacement of FMC roadway surrounding rocks and those governing deformation of supports are basically the same along the strike, but the displacements vary greatly. The front stresses affect greater areas than the lateral stresses and their limit widths of equilib-rium zones and K are almost similar. The stress transmits very deep. Our findings offer scientific basis on which to determine parameters for coal pillar retaining and for roadway out-laying, thus increasing the recovery ratio and improving the maintenance of roadway.
基金the National Natural Science Foundation of China (No.60573141, 70271050)the Natural Science Foundation of Jiangsu Province (No.BK2005146)+3 种基金the High Technology Research Programme of Jiangsu Prov-ince (No.BG2005037, BG2005038, BG2006001)the High Technology Research Programme of Nanjing (No. 2006RZ105)the Foundation of National Laboratory for Modern Communications (No.9140C1101010603)the Key Laboratory of Information Technology Processing of Jiangsu Province (No.kjs05001, kjs0606).
文摘In order to effectively control the random tasks submitted and executed in grid workflow,a grid workflow model based on hybrid petri-net is presented. This model is composed of random petri-net,colored petri-net and general petri-net. Therein random petri-net declares the relationship between the number of grid users' random tasks and the size of service window and computes the server intensity of grid system. Colored petri-net sets different color for places with grid services and provides the valid interfaces for grid resource allocation and task scheduling. The experiment indicated that the model presented in this letter could compute the valve between the number of users' random tasks and the size of grid service window in grid workflow management system.
基金Supported by the National Natural Science Foundation of China (Nos. 50834005 and 51074163)the Ministry of Education Support Program for New Century Excellent of China(No. NCET-08-0837)+1 种基金the Fundamental Research Funds for the Central Universities of ChinaYouth Science and Technology Foundation of China University of Mining and Technology(No. 2010QNB25)
文摘"Riding mining" is a form of mining where the working face is located above the roadway and advances parallel to it.Riding mining in deep soft rock creates a particular set of problems in the roadway that include high stresses,large deformations,and support difficulties.Herein we describe a study of the rock deformation mechanism of a roadway as observed during riding mining in deep soft rock.Theoretical analysis,numerical simulations,and on site monitoring were used to examine this problem.The stress in the rock and the visco-elastic behavior of the rock are considered.Real time data,recorded over a period of 240 days,were taken from a 750 transportation roadway.Stress distributions in the rock surrounding the roadway were studied by comparing simulations to observations from the mine.The rock stress shows dynamic behavior as the working face advances.The pressure increases and then drops after peaking as the face advances.Both elastic and plastic deformation of the surrounding rock occurs.Plastic deformation provides a mechanism by which stress in the rock relaxes due to material flow.A way to rehabilitate the roadway is suggested that will help ensure mine safety.
文摘Oceanographic survey, or other similar applications should be the applications of multiple AUVs. In this paper, the skill & simulation based hybrid control architecture (S2BHCA) as the controller's design reference was proposed. It is a multi-robot cooperation oriented intelligent control architecture based on hybrid ideas. The S2 BHCA attempts to incorporate the virtues of the reactive controller and of the deliberative controller by introducing the concept of the "skill". The additional online task simulation ability for cooperation is supported, too. As an application, a multiple AUV control system was developed with three "skills" for the MCM mission including two different cooperative tasks. The simulation and the sea trials show that simple task expression, fast reaction and better cooperation support can be achieved by realizing the AUV controller based on the S2 BHCA.
文摘The design and development Web 2.0-based education management system will satisfy with the school education management of informationization, scientific and modernized request, the auxiliary education superintendent carries on the correct decision-making, enhance the education management working efficiency. This system has used the quite mature development technology at present, the function of realizes is more perfect, usable; The man-machine interaction is friendly and operate easily. Its application, enhanced the administrator and teacher's working efficiency greatly, reduces the working strength, simultaneously has also provided the better education condition for the student. With the rapid development of network,, education management system will be more widespread in the education of education application, it will create a new situation of the education management, bring a brighter prospect of the application.
基金Supported by The national natural Science Foundation of China (Grant No.50172009).
文摘The paper analyzes the influence of lead toxicity by anaerobic granule sludge inhibition and recovering experiments. The result shows that there are different inhibition types at differ-ent lead contents. Higher lead content leads to more inhibition granular sludge, and at the same time, the time of gas recovery is different. Lower lead content per microorganism results in sooner sludge recovery. Microorganisms have a good ability to resist lead toxicity.
文摘Based on the characteristics of the ripping of rock, the simulated conditions that would be satisfied by the prototype ripping and the model ripping have been derived in this paper. In order to .nanufacture the satisfying equivalent materials for the model ripping, a new method has been set up, and the materials, which can simulate the prototype rock "Hawkesbury sandstone", have been made by using the methed.
文摘The noise level of coal face by full-mechanized coal winning technology was measured in a coal mine. And then it was analyzed and evaluated using environment science, ergonomics and fussy mathematics analysis. Basis of the statistics and analysis of the measured noise level some measures, such as applying the new materials and improving the construction of the equipment, were carried out. The resuts show that they can reduce the noise level, improve the working environment and enhance the work efficiency.
文摘Over the course of the past 70 years, the objectives of CA (cellular automata) research shifted from speculative and illustrative purposes without immediate goals outside of given implementations to the more utilitarian scientific and engineering objectives of simulating, controlling and predicting other phenomena. Looking back at our own 10-year history of CA related work, however, we recognize a generally inverse tendency from utilitarian objectives to finding more illustrative and speculative value. In this paper, we present a reflection on our own body of CA work, and we discuss the qualities of the various outcomes and insights we gained from a second-order cybernetic perspective. We argue that much of our own CA work may best be understood as creating machines for showing and for repurposing that allow their observers to gain new (second-order cybernetic) ways of seeing from interacting with them.
文摘XY table automated assembly machines ensure time saving and quality improving in the electronics industry. Recently, due to the need of higher operation speeds and lighter machines in PCB (Printed Circuit Board) assembly, a challenging problem has arisen which is the table positioning vibration. The high speed with the machine flexibility, make the positioning vibration inevitable although the inner control. The positioning vibration is to be reduced otherwise the machine becomes useless. Firstly, the machine is modeled, the positioning vibration is formulated, and then analyzed. Secondly, using the analysis, three direct control methods are identified to decrease the positioning vibration, they are based on the kinematics, dynamics, and operation of the machine. Thirdly, the methods are examined numerically to evaluate their efficiency. Lastly, the identified methods are discussed to conclude on their application. The results are a real contribution in the vibration control of XY table automated assembly machines, which is classified as industrial knowhow.
文摘The retirement age policy adjustment is again sharing the cost of the aging process, incentives to delay retirement life expectancy means that workers work longer. Developed by the elastic mechanism into retirement system framework, improve the flexibility of the retirement system, in curbing early retirement incentives to delay retirement, improve the elderly labor force participation rate, and achieved some success. The reform of the retirement system gradually into public view. To adapt to China's national conditions for the establishment of flexible retirement mechanism, western countries need to discuss flexible retirement system, in-depth analysis of the establishment of the special constraints flexible retirement mechanism, good theoretical advance preparation for retirement Mechanism.
文摘In this work, the stability of an endoreversible Curzon-Ahlbom engine is analyzed, using Van der Waals gas as a working substance and the corresponding efficiency for this engine working at temperatures withinthe maximum ecological regime. By mean s of a local stability analysis we find that a critical point of an almost linear system is stable andanalytically expressed in eigenvalues. After an arbitrarily small perturbation, the system state exponentially decays to a critical point, with either of two characteristic relaxation times, which are a function of the thermal conductance (a), heat capacity (C) and T=T2/T1. The behavior of relaxation times and solution of the systems are qualitatively shown by sketching its phase portrait, which results susceptible to operating regimes, i.e., the eigenvectors in the maximum ecological regime have a clockwise rotation with respect to the eigenvectors in the regime of maximumpower. Finally, it has to observe that afterto λvw = 1, approximation,ηVWE=4^-3ηC is obtained, where ηVWE is the Van der Waals efficiency atrnaximum ecological regime and r/c is Carnot's efficiency. Finally, it discussed the local stability and steady state of the energetic properties of the endoreversible engine.
文摘In this paper, design and fabrication of a commemorative plaque are described and presented. The plaque was fabricated to honour the memory of the 14 women massacred at L'Ecole Polytechnique in Montreal. This plaque is the result of a project partnership between the Faculties of Engineering and Fine Arts, and was sponsored by the Office of the Vice-President Academic and Provost. An art design was selected through a contest coordinated by the Visual Arts Departmment. The selected art design was then turned over to the Mechanical Engineering Department to be converted to a 3-dimensional (3D) solid model and then eventually fabricated on a computer numerical control (CNC) milling machine. The fabricated plaque was unveiled during the December 2010 Memorial event at UVic.
基金supported by the National Natural Science Foundation of China (Grant No. 61075101)the Research Fund of State Key Laboratory of MSV,China (Grant No. MSV-2010-01)+1 种基金the Medical and Technology Intercrossing Research Foundation (Grant No. YG2010ZD101)the Science and Technology Intercrossing Research Foundation of Shanghai Jiaotong University
文摘This paper presents a bioelectrochemical model for the activation of action potentials on sarcolemma and variation of Ca2+ concentration in sarcomeres of skeletal muscle fibers.The control mechanism of muscle contraction generated by collective motion of molecular motors is elucidated from the perspective of variable-frequency regulation,and action potential with variable frequency is proposed as the control signal to directly regulate Ca2+ concentration and indirectly control isometric tension.Furthermore,the transfer function between stimulation frequency and Ca2+ concentration is deduced,and the frequency domain properties of muscle contraction are analyzed.Moreover the conception of "electro-muscular time constant" is defined to denote the minimum delay time from electric stimulation to muscle contraction.Finally,the experimental research aiming at the relation between tension and stimulation frequency of action potential is implemented to verify the proposed variable-frequency control mechanism,whose effectiveness is proved by good consistence between experimental and theoretical results.