Truth-conditional approaches to tense and other temporal expressions have relied on both linear-time and branching-time frameworks as needed. However, in the truth-conditional enterprise generally, it seems advisable ...Truth-conditional approaches to tense and other temporal expressions have relied on both linear-time and branching-time frameworks as needed. However, in the truth-conditional enterprise generally, it seems advisable to settle on a single depiction of time. Linear time is the simpler framework, and branching time faces difficulties for which we seem to have no immediate solutions. This paper defends the applicability of linear time. The apparent branching of time results from the use of speech acts other than factual assertion. Truth in correspondence with specific conditions is relevant when making factual assertions. However, we are in no epistemic position to advance factual assertions about the future, but only suppositions and predictions. For these, the truth-conditional content is employed differently. For suppositions and predictions, we only ＂pretend＂ to reference things, to assert facts, and to accept them as ＂true.＂ There is a wide array of alternatives about what we can suppose or predict, giving the impression of branching options. Suppositions and predictions under active consideration are often marked with present tense, whereas those that are inactive （not presently under active consideration but nonetheless relevant） are often marked with past tense.展开更多
In the process of numerical control machining simulation,the workpiece surface is usually described with the uniform triangular mesh model.To alleviate the contradiction between the simulation speed and accuracy in th...In the process of numerical control machining simulation,the workpiece surface is usually described with the uniform triangular mesh model.To alleviate the contradiction between the simulation speed and accuracy in this model,two improved methods,i.e.,the local refinement triangular mesh modeling method and the adaptive triangular mesh modeling method were presented.The simulation results show that when the final shape of the workpiece is known and its mathematic representation is simple,the local refinement triangular mesh modeling method is preferred;when the final shape of the workpiece is unknown and its mathematic description is complicated,the adaptive triangular mesh modeling method is more suitable.The experimental results show that both methods are more targeted and practical and can meet the requirements of real-time and precision in simulation.展开更多
In this paper, we establish a surface electromyography(sEMG) signal model and study the signal decomposition method from noisy background. Firstly, single fiber action potential (SFAP), motor unit action potential (MU...In this paper, we establish a surface electromyography(sEMG) signal model and study the signal decomposition method from noisy background. Firstly, single fiber action potential (SFAP), motor unit action potential (MUAP) and motor unit action potential train(MUAPT) are simulated based on the tripolar signal source model, and then the sEMG is obtained; secondly, the simulated sEMG signal is extracted from the mixed signals that consists of white noises, power frequency interference signal and electrocardio signal by independent component analysis (ICA) algorithms; lastly, the spikes corresponding to each motor unit action potential from the simulated sEMG signals were detected by applying the wavelet transform (WT) method. Simulation results showed that sEMG model could describe the physiological process of sEMG, ICA and WT methods could extract the sEMG signal and its features, which will lay a foundation for further classifying the MUAP.展开更多
文摘Truth-conditional approaches to tense and other temporal expressions have relied on both linear-time and branching-time frameworks as needed. However, in the truth-conditional enterprise generally, it seems advisable to settle on a single depiction of time. Linear time is the simpler framework, and branching time faces difficulties for which we seem to have no immediate solutions. This paper defends the applicability of linear time. The apparent branching of time results from the use of speech acts other than factual assertion. Truth in correspondence with specific conditions is relevant when making factual assertions. However, we are in no epistemic position to advance factual assertions about the future, but only suppositions and predictions. For these, the truth-conditional content is employed differently. For suppositions and predictions, we only ＂pretend＂ to reference things, to assert facts, and to accept them as ＂true.＂ There is a wide array of alternatives about what we can suppose or predict, giving the impression of branching options. Suppositions and predictions under active consideration are often marked with present tense, whereas those that are inactive （not presently under active consideration but nonetheless relevant） are often marked with past tense.
基金Project(60772089) supported by the National Natural Science Foundation of ChinaProject(20080440939) supported by the China Postdoctoral Science Foundation
文摘In the process of numerical control machining simulation,the workpiece surface is usually described with the uniform triangular mesh model.To alleviate the contradiction between the simulation speed and accuracy in this model,two improved methods,i.e.,the local refinement triangular mesh modeling method and the adaptive triangular mesh modeling method were presented.The simulation results show that when the final shape of the workpiece is known and its mathematic representation is simple,the local refinement triangular mesh modeling method is preferred;when the final shape of the workpiece is unknown and its mathematic description is complicated,the adaptive triangular mesh modeling method is more suitable.The experimental results show that both methods are more targeted and practical and can meet the requirements of real-time and precision in simulation.
基金The open project of the State Key Laboratory of Robotics and System(HIT)the open project of the State Key Laboratory of Cognitive Neuroscience and Learning and the Natural science fund for colleges and universities in Jiangsu Province+2 种基金 grant number: 10KJB510003the natural science fund in Changzhou City grant number: CJ20110023
文摘In this paper, we establish a surface electromyography(sEMG) signal model and study the signal decomposition method from noisy background. Firstly, single fiber action potential (SFAP), motor unit action potential (MUAP) and motor unit action potential train(MUAPT) are simulated based on the tripolar signal source model, and then the sEMG is obtained; secondly, the simulated sEMG signal is extracted from the mixed signals that consists of white noises, power frequency interference signal and electrocardio signal by independent component analysis (ICA) algorithms; lastly, the spikes corresponding to each motor unit action potential from the simulated sEMG signals were detected by applying the wavelet transform (WT) method. Simulation results showed that sEMG model could describe the physiological process of sEMG, ICA and WT methods could extract the sEMG signal and its features, which will lay a foundation for further classifying the MUAP.
