Taking into consideration the disadvantage of Balanced Scorecard(BSC)not being able to reflect time delay,nonlinear problems of causal relationship and being lack of effective simulation,we combined it with the charac...Taking into consideration the disadvantage of Balanced Scorecard(BSC)not being able to reflect time delay,nonlinear problems of causal relationship and being lack of effective simulation,we combined it with the characteristics of the System Dynamics(SD).Basing on the background of manufacturing enterprises,through SD integrating with the BSC we established a new performance evaluation method-SD-BSC method to overcome the disadvantage of BSC.A performance evaluation model of SD-BSC is provided and the simulation results are analyzed which show different production policies will lead to different customer's satisfaction degrees.The SD-BSC dynamic performance evaluation method can reflect dynamic,complex causal feedback relationship and time delay,so it compensates for the disadvantage of traditional financial performance evaluation method,and at the same time makes the BSC perfect.展开更多
The active control of rotor vibration was studied while shape memory alloy （SMA） spring component was chosen as bearing of rotor system. The vibration of rotor system was controlled by the phase transformation of SM...The active control of rotor vibration was studied while shape memory alloy （SMA） spring component was chosen as bearing of rotor system. The vibration of rotor system was controlled by the phase transformation of SMA with electric heating method. The SMA spring component has nonlinear coupling problem of thermal stress and thermal elasticity,because thermal constants α,β and elasticity constants λ,G vary with temperature when temperature changes sharply. Because δ,ε were both small parameters, their square items could be ignored and approximate results were obtained by perturbation. The characters of α,β,λ,G changing with temperature were analyzed. Results show that the character of thermal diffusivity α changes with temperature, which cannot influence U,Ψ,So the nonlinearity of α can be ignored; the character of β changes with temperature, which cannot influence U, but influences Ψ at high temperature; the character of λ,G change with temperature, which cannot influence Ψ, but influences U with U（01） ε. The more λ,G, the more their influence on U; the nonlinearity of βTρcvεkk influences U and Ψ, which must be calculated.展开更多
In this paper, Endurance Time Analysis （ETA） method which is a new time-history based dynamic pushover procedure is introduced and its application in linear analysis of concrete arch dams is investigated. In this me...In this paper, Endurance Time Analysis （ETA） method which is a new time-history based dynamic pushover procedure is introduced and its application in linear analysis of concrete arch dams is investigated. In this method the structure is subjected to gradually intensifying acceleration functions and its performance is evaluated based on the length of the time duration that can satisfy required performance criteria. For this purpose Dez arch dam is selected as case study, fluid-structure interaction is taken into account and F.E. model of the system is excited in three performance levels. ETA method gives an approximation of maximum response at the equivalent target time, resulted from analyzing the system based on natural records. Extracted results are displacement, velocity and acceleration of the crest at crown cantilever. Results show using of ETA method can reduce at least 50% in number of analyses and 70% in total time of analyses at the current case. Furthermore, it is found that although the results of the ETA are not exactly consistent with the results of time-history analyses using real ground motions, errors are reasonable and ETA can identify performance levels of the dam with acceptable accuracy.展开更多
The thermodynamic aspect of a compression type heat pump （HP） is briefly described and special attention is given to investigation of condensing temperature influence on heat pump efficiency in heating mode, express...The thermodynamic aspect of a compression type heat pump （HP） is briefly described and special attention is given to investigation of condensing temperature influence on heat pump efficiency in heating mode, expressed by its coefficient of performance （COP）. Heat pumps are usually applied for the purposes of heating and cooling of energy efficient buildings where they have advantages in low-temperature systems, as it is well documented in the paper. The comparison of real thermodynamic processes with thermodynamically most favorable Camot＇s process is made. The results in the paper show that COP is diminishing with increasing of condensing temperature and also depends on real properties of working fluids. The impact of compressor efficiency for two real working media is also analyzed in the paper. There is significant diminishing of COP with diminishing of compressor efficiency. The intension of the paper is to help better understanding of this very effective and prosperous technology, and to encourage its development, production, and efficient application.展开更多
Surface texturing has been considered as an effective approach to improve the tribological performances.Based on the consideration of enhancing the tribological performance,the experiments are carried out to investiga...Surface texturing has been considered as an effective approach to improve the tribological performances.Based on the consideration of enhancing the tribological performance,the experiments are carried out to investigate tribological performance of triangular textures in water lubrication.The textures are generated by the Nd:YAG laser marking system,with an area density of 20%and a depth of 7 m and are distributed uniformly on the surface of the SiC rings.Compared with the circular textures,the triangular textures have obvious tribological anisotropy.The triangular textures in clockwise direction show the best friction reduction effect among the three textures.The friction reduction mechanisms of the triangular textures in clockwise direction are also analyzed and discussed.展开更多
Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual impr...Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual imprinting itself evolves. Theoretical work on polygynous mating systems predicts that females will evolve paternal imprinting, which means they learn to prefer phenotypes expressed by their fathers. In nature however, females of some species learn to prefer phenotypes expressed by their mothers instead. We used a dynamical systems model and tools from adaptive dynamics to study how sexual imprinting evolves in species with socially monogamous mating systems. We considered cases in which the target trait for imprinting is un- der viability selection but is not a reliable signal of paternal investment. Thus, the target trait signals the genetic benefits rather than the parental care benefits of mate choice. When mating is socially monogamous and there is some extra-pair patemity, we show that maternal imprinting can be favored over paternal imprinting. Counterintuitively, females often become choosier when selecting social partners in systems where extra-pair mating is more frequent. That is, females may be more selective when choosing social partners that will sire a smaller percentage of their offspring. Our results offer new testable hypotheses, and ad- vance our understanding of the mechanisms that drive the evolution of mate choice strategies in nature .展开更多
The massive diffusion of smartphones, the growing interest in wearable devices and the Internet of Things, and the exponential rise of location based services（LBSs） have made the problem of localization and navigati...The massive diffusion of smartphones, the growing interest in wearable devices and the Internet of Things, and the exponential rise of location based services（LBSs） have made the problem of localization and navigation inside buildings one of the most important technological challenges of recent years. Indoor positioning systems have a huge market in the retail sector and contextual advertising; in addition, they can be fundamental to increasing the quality of life for citizens if deployed inside public buildings such as hospitals, airports, and museums.Sometimes, in emergency situations, they can make the difference between life and death. Various approaches have been proposed in the literature. Recently, thanks to the high performance of smartphones＇ cameras, marker-less and marker-based computer vision approaches have been investigated. In a previous paper, we proposed a technique for indoor localization and navigation using both Bluetooth low energy（BLE） and a 2D visual marker system deployed into the floor. In this paper, we presented a qualitative performance evaluation of three 2D visual markers, Vuforia,Ar Uco marker, and AprilT ag, which are suitable for real-time applications. Our analysis focused on specific case study of visual markers placed onto the tiles, to improve the efficiency of our indoor localization and navigation approach by choosing the best visual marker system.展开更多
基金Sponsored by the Key Science Research Project of Abroad Scholars of Heilongjiang Province(Grant No.1055HZ029).
文摘Taking into consideration the disadvantage of Balanced Scorecard(BSC)not being able to reflect time delay,nonlinear problems of causal relationship and being lack of effective simulation,we combined it with the characteristics of the System Dynamics(SD).Basing on the background of manufacturing enterprises,through SD integrating with the BSC we established a new performance evaluation method-SD-BSC method to overcome the disadvantage of BSC.A performance evaluation model of SD-BSC is provided and the simulation results are analyzed which show different production policies will lead to different customer's satisfaction degrees.The SD-BSC dynamic performance evaluation method can reflect dynamic,complex causal feedback relationship and time delay,so it compensates for the disadvantage of traditional financial performance evaluation method,and at the same time makes the BSC perfect.
文摘The active control of rotor vibration was studied while shape memory alloy （SMA） spring component was chosen as bearing of rotor system. The vibration of rotor system was controlled by the phase transformation of SMA with electric heating method. The SMA spring component has nonlinear coupling problem of thermal stress and thermal elasticity,because thermal constants α,β and elasticity constants λ,G vary with temperature when temperature changes sharply. Because δ,ε were both small parameters, their square items could be ignored and approximate results were obtained by perturbation. The characters of α,β,λ,G changing with temperature were analyzed. Results show that the character of thermal diffusivity α changes with temperature, which cannot influence U,Ψ,So the nonlinearity of α can be ignored; the character of β changes with temperature, which cannot influence U, but influences Ψ at high temperature; the character of λ,G change with temperature, which cannot influence Ψ, but influences U with U（01） ε. The more λ,G, the more their influence on U; the nonlinearity of βTρcvεkk influences U and Ψ, which must be calculated.
文摘In this paper, Endurance Time Analysis （ETA） method which is a new time-history based dynamic pushover procedure is introduced and its application in linear analysis of concrete arch dams is investigated. In this method the structure is subjected to gradually intensifying acceleration functions and its performance is evaluated based on the length of the time duration that can satisfy required performance criteria. For this purpose Dez arch dam is selected as case study, fluid-structure interaction is taken into account and F.E. model of the system is excited in three performance levels. ETA method gives an approximation of maximum response at the equivalent target time, resulted from analyzing the system based on natural records. Extracted results are displacement, velocity and acceleration of the crest at crown cantilever. Results show using of ETA method can reduce at least 50% in number of analyses and 70% in total time of analyses at the current case. Furthermore, it is found that although the results of the ETA are not exactly consistent with the results of time-history analyses using real ground motions, errors are reasonable and ETA can identify performance levels of the dam with acceptable accuracy.
文摘The thermodynamic aspect of a compression type heat pump （HP） is briefly described and special attention is given to investigation of condensing temperature influence on heat pump efficiency in heating mode, expressed by its coefficient of performance （COP）. Heat pumps are usually applied for the purposes of heating and cooling of energy efficient buildings where they have advantages in low-temperature systems, as it is well documented in the paper. The comparison of real thermodynamic processes with thermodynamically most favorable Camot＇s process is made. The results in the paper show that COP is diminishing with increasing of condensing temperature and also depends on real properties of working fluids. The impact of compressor efficiency for two real working media is also analyzed in the paper. There is significant diminishing of COP with diminishing of compressor efficiency. The intension of the paper is to help better understanding of this very effective and prosperous technology, and to encourage its development, production, and efficient application.
基金supported by the National Basic Research Program of China(Grant No.2009CB724304)the National Key Technology R&D Program(Grant No.2011BAF09B05)the National Natural Science Foundation of China(Grant No.50975157)
文摘Surface texturing has been considered as an effective approach to improve the tribological performances.Based on the consideration of enhancing the tribological performance,the experiments are carried out to investigate tribological performance of triangular textures in water lubrication.The textures are generated by the Nd:YAG laser marking system,with an area density of 20%and a depth of 7 m and are distributed uniformly on the surface of the SiC rings.Compared with the circular textures,the triangular textures have obvious tribological anisotropy.The triangular textures in clockwise direction show the best friction reduction effect among the three textures.The friction reduction mechanisms of the triangular textures in clockwise direction are also analyzed and discussed.
文摘Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual imprinting itself evolves. Theoretical work on polygynous mating systems predicts that females will evolve paternal imprinting, which means they learn to prefer phenotypes expressed by their fathers. In nature however, females of some species learn to prefer phenotypes expressed by their mothers instead. We used a dynamical systems model and tools from adaptive dynamics to study how sexual imprinting evolves in species with socially monogamous mating systems. We considered cases in which the target trait for imprinting is un- der viability selection but is not a reliable signal of paternal investment. Thus, the target trait signals the genetic benefits rather than the parental care benefits of mate choice. When mating is socially monogamous and there is some extra-pair patemity, we show that maternal imprinting can be favored over paternal imprinting. Counterintuitively, females often become choosier when selecting social partners in systems where extra-pair mating is more frequent. That is, females may be more selective when choosing social partners that will sire a smaller percentage of their offspring. Our results offer new testable hypotheses, and ad- vance our understanding of the mechanisms that drive the evolution of mate choice strategies in nature .
文摘The massive diffusion of smartphones, the growing interest in wearable devices and the Internet of Things, and the exponential rise of location based services（LBSs） have made the problem of localization and navigation inside buildings one of the most important technological challenges of recent years. Indoor positioning systems have a huge market in the retail sector and contextual advertising; in addition, they can be fundamental to increasing the quality of life for citizens if deployed inside public buildings such as hospitals, airports, and museums.Sometimes, in emergency situations, they can make the difference between life and death. Various approaches have been proposed in the literature. Recently, thanks to the high performance of smartphones＇ cameras, marker-less and marker-based computer vision approaches have been investigated. In a previous paper, we proposed a technique for indoor localization and navigation using both Bluetooth low energy（BLE） and a 2D visual marker system deployed into the floor. In this paper, we presented a qualitative performance evaluation of three 2D visual markers, Vuforia,Ar Uco marker, and AprilT ag, which are suitable for real-time applications. Our analysis focused on specific case study of visual markers placed onto the tiles, to improve the efficiency of our indoor localization and navigation approach by choosing the best visual marker system.
