We have created an inchworm robot capable of the two-anchor crawl gait on level ground and inclined plane. The main novelty is in the design of the inchworm： （1） three-part body that is 3D printed and actuated by t...We have created an inchworm robot capable of the two-anchor crawl gait on level ground and inclined plane. The main novelty is in the design of the inchworm： （1） three-part body that is 3D printed and actuated by two servo motors to allow a looping and lengthening action, （2） passive friction pads to anchor the feet, each of which may be disengaged using a servo motor actuated lever arm, and （3） modular body and electronics. The robot is about 2 feet （61 cm） in length, has a mass of about 4 kg, and uses an open-loop controller to achieve steady crawling gait. The inchworm robot achieved a speed of 2.54 em.sI on level ground as well as on an incline plane of 19~. The energy usage as measured by the Mechanical Cost of Transport （a non-dimensional number defined as the energy used per unit weight per unit distance moved） is 3.34. Our results indicate that simple robotic designs that copy the basic features of natural organisms provide a promising alternative over conventional wheeled robots.展开更多
Sentiment analysis is a method to identify and understand the emotion in the text through NLP and text analysis. In the era of information technology, there is often a certain error between the comments on the movie w...Sentiment analysis is a method to identify and understand the emotion in the text through NLP and text analysis. In the era of information technology, there is often a certain error between the comments on the movie website and the actual score of the movie, and sentiment analysis technology provides a new way to solve this problem. In this paper, Python is used to obtain the movie review data from the Douban platform, and the model is constructed and trained by using naive Bayes and Bi-LSTM. According to the index, a better Bi-LSTM model is selected to classify the emotion of users’ movie reviews, and the classification results are scored according to the classification results, and compared with the real ratings on the website. According to the error of the final comparison results, the feasibility of this technology in the scoring direction of film reviews is being verified. By applying this technology, the phenomenon of film rating distortion in the information age can be prevented and the rights and interests of film and television works can be safeguarded.展开更多
In order to move vehicles with automated mechanical transmission （AMT） a little bit of distance, such as reversing into or moving in a garage, a control strategy for crawling vehicles was proposed. Based on the dyna...In order to move vehicles with automated mechanical transmission （AMT） a little bit of distance, such as reversing into or moving in a garage, a control strategy for crawling vehicles was proposed. Based on the dynamic analysis of vehicle starting process and requirements of crawl driv- ing for the vehicle, a control strategy of the clutch was designed. The strategy increased the.slipping friction torque first and then decreased it, in order to realize the crawl driving. The speed increased by the engagement of the clutch, and then the clutch turned to disengage to the half disengage point, when the speed met the requirements. Based on the control strategy, a control software was de- signed. In the end, the software was tested on a vehicle with AMT. The lowest steady vehicle speed was reduced to 40% of the original value, which was set in the control strategy.展开更多
FastDu is a file system service that tracks file system changes by intercepting file system calls to maintain directory summaries, which play important roles in both storage administration and improvement of user expe...FastDu is a file system service that tracks file system changes by intercepting file system calls to maintain directory summaries, which play important roles in both storage administration and improvement of user experiences for some applications. In most circumstances, directory summaries are independently harvested by applications via traversing the file system hierarchy and calling stat 0 on every file in each directory. For large file systems, this brute-force traverse-based approach can take many hours to complete, even if only a small percentage of the files have changed. This paper describes FastDu, which uses a pre-built database to store harvested directory summaries, and tracks the file system changes by intercept- ing file system calls, so that new harvesting is restricted to the small subset of directories that contain modified files. Tests using FastDu show that this approach reduces the time needed to get a directory summary by one or two orders of magnitude with almost negligible penalty to application-aware file system performance.展开更多
基金This work was partially supported by the United States National Science Foundation through the grant 1566463 to P. A. Bhounsule.
文摘We have created an inchworm robot capable of the two-anchor crawl gait on level ground and inclined plane. The main novelty is in the design of the inchworm： （1） three-part body that is 3D printed and actuated by two servo motors to allow a looping and lengthening action, （2） passive friction pads to anchor the feet, each of which may be disengaged using a servo motor actuated lever arm, and （3） modular body and electronics. The robot is about 2 feet （61 cm） in length, has a mass of about 4 kg, and uses an open-loop controller to achieve steady crawling gait. The inchworm robot achieved a speed of 2.54 em.sI on level ground as well as on an incline plane of 19~. The energy usage as measured by the Mechanical Cost of Transport （a non-dimensional number defined as the energy used per unit weight per unit distance moved） is 3.34. Our results indicate that simple robotic designs that copy the basic features of natural organisms provide a promising alternative over conventional wheeled robots.
文摘Sentiment analysis is a method to identify and understand the emotion in the text through NLP and text analysis. In the era of information technology, there is often a certain error between the comments on the movie website and the actual score of the movie, and sentiment analysis technology provides a new way to solve this problem. In this paper, Python is used to obtain the movie review data from the Douban platform, and the model is constructed and trained by using naive Bayes and Bi-LSTM. According to the index, a better Bi-LSTM model is selected to classify the emotion of users’ movie reviews, and the classification results are scored according to the classification results, and compared with the real ratings on the website. According to the error of the final comparison results, the feasibility of this technology in the scoring direction of film reviews is being verified. By applying this technology, the phenomenon of film rating distortion in the information age can be prevented and the rights and interests of film and television works can be safeguarded.
基金Supported by the National Natural Science Foundation of China ( 51205209)
文摘In order to move vehicles with automated mechanical transmission （AMT） a little bit of distance, such as reversing into or moving in a garage, a control strategy for crawling vehicles was proposed. Based on the dynamic analysis of vehicle starting process and requirements of crawl driv- ing for the vehicle, a control strategy of the clutch was designed. The strategy increased the.slipping friction torque first and then decreased it, in order to realize the crawl driving. The speed increased by the engagement of the clutch, and then the clutch turned to disengage to the half disengage point, when the speed met the requirements. Based on the control strategy, a control software was de- signed. In the end, the software was tested on a vehicle with AMT. The lowest steady vehicle speed was reduced to 40% of the original value, which was set in the control strategy.
基金Supported by the National Key Basic Research and Development Program (973) of China (No. 2011CB302505)the National Natural Science Foundation of China (Nos. 60803121 and 61073165)the National High-Tech Research and Development (863) Program of China (Nos. 2010AA012401 and 2009AA01A130)
文摘FastDu is a file system service that tracks file system changes by intercepting file system calls to maintain directory summaries, which play important roles in both storage administration and improvement of user experiences for some applications. In most circumstances, directory summaries are independently harvested by applications via traversing the file system hierarchy and calling stat 0 on every file in each directory. For large file systems, this brute-force traverse-based approach can take many hours to complete, even if only a small percentage of the files have changed. This paper describes FastDu, which uses a pre-built database to store harvested directory summaries, and tracks the file system changes by intercept- ing file system calls, so that new harvesting is restricted to the small subset of directories that contain modified files. Tests using FastDu show that this approach reduces the time needed to get a directory summary by one or two orders of magnitude with almost negligible penalty to application-aware file system performance.
