Vibration-based pavement condition(roughness and obvious anomalies)monitoring has been expanding in road engineering.However,the indistinctive transverse cracking has hardly been considered.Therefore,a vehicle-based n...Vibration-based pavement condition(roughness and obvious anomalies)monitoring has been expanding in road engineering.However,the indistinctive transverse cracking has hardly been considered.Therefore,a vehicle-based novel method is proposed for detecting the transverse cracking through signal processing techniques and support vector machine(SVM).The vibration signals of the car traveling on the transverse-cracked and the crack-free sections were subjected to signal processing in time domain,frequency domain and wavelet domain,aiming to find indices that can discriminate vibration signal between the cracked and uncracked section.These indices were used to form 8 SVM models.The model with the highest accuracy and F1-measure was preferred,consisting of features including vehicle speed,range,relative standard deviation,maximum Fourier coefficient,and wavelet coefficient.Therefore,a crack and crack-free classifier was developed.Then its feasibility was investigated by 2292 pavement sections.The detection accuracy and F1-measure are 97.25%and 85.25%,respectively.The cracking detection approach proposed in this paper and the smartphone-based detection method for IRI and other distress may form a comprehensive pavement condition survey system.展开更多
A novel twin-rotor piston engine （TRPE） mechanism with high volumetric output and power density was introduced. This new engine comprises an energy conversion system and a differential velocity drive mechanism （DVD...A novel twin-rotor piston engine （TRPE） mechanism with high volumetric output and power density was introduced. This new engine comprises an energy conversion system and a differential velocity drive mechanism （DVDM）. Two special geared four-bar mechanisms, DVDM-1 and DVDM-2, were utilized and compared. Based on the closed loop vector method, a mathematical model for position, velocity, and acceleration of the two mechanisms was established. Numerical examples illustrate that the kinematic characteristics were presented. Expression of the displacement and compression ratio of the two engine mechanisms were derived and compared. It is concluded that both DVDM-1 and DVDM-2 adopted in the proposed TRPE with six vane pistons create thirty-six power strokes per revolution of the output shaft, and the summation of two angles covered by each rocker is always 2x/N as the output shaft rotates an angle of x/N. In DVDM-1, the span angle of a vane piston should be designed to be 10.2°, and the compression ratio should be equal to 10; in DVDM-2, the span angle of a vane piston should be designed to be 10.6°, and the compression ratio should be equal to 4.3.展开更多
This study investigated the difference in the levels of people＇s acceptance of robots by the types of social relationships between humans and robots. In this study, social relationships between a robot and a person w...This study investigated the difference in the levels of people＇s acceptance of robots by the types of social relationships between humans and robots. In this study, social relationships between a robot and a person were categorized into four types consisted of two in the horizontal of social relationship （intimacy dimension） and two in the vertical of social relationship （status dimension）. In dialogue between humans and robots, the types of social relationship were adjusted by forms of language such as calling by name and speech styles. People＇s acceptance of robots was measured by people＇s comfortable approach distance to the robot. Participants showed greater acceptance of a robot when the robot called them by their names. In the case of speech style, participants accepted the robot which used honorific speech style without addressing them by their name, while they accepted the robot which used familiar speech style with addressing them by their name. There was an interaction effect between gender and calling by name.展开更多
Education of veterinarians in animal welfare issues is important to improve the welfare and health of animals. A questionnaire to 250 veterinarians related to their knowledge on animal welfare issues has been carried ...Education of veterinarians in animal welfare issues is important to improve the welfare and health of animals. A questionnaire to 250 veterinarians related to their knowledge on animal welfare issues has been carried out at the Veterinary School of the University of the Republic, Uruguay, during March-April 2012. The questions were related to the courses on animal welfare veterinarians received, their main field of work, the importance given to the information offered and the quality of the topics addressed. From the total of veterinarians surveyed, 45% （112） answered the questionnaire. Of those who responded, 47% attended to three or more animal welfare courses, 18% assisted to two courses and 22% to one. The occupation of the 82% of respondents was with beef and dairy cattle （large animals） or in the meat industry equally. 10% works with small animals （especially pets） and poultry （production and industry）. The 95% of respondents considered that animal welfare is very important for their daily work with animals 65% reported that animal welfare concepts have high applicability in their job. 85% considered that animal welfare should be part of the veterinary curricula and 100% expressed their compliance to be present in other courses on the subject. These results emphasize the importance afforded by Uruguayan veterinarians to improve their knowledge on animal welfare and to continue including specific courses in the veterinary curricula.展开更多
We present an analytical analysis of the spatial resolution of quantum ghost imaging implemented by entangled photons from a general, spontaneously parametric, down-conversion process. We find that the resolution is a...We present an analytical analysis of the spatial resolution of quantum ghost imaging implemented by entangled photons from a general, spontaneously parametric, down-conversion process. We find that the resolution is affected by both the pump beam waist and the nonlinear crystal length. Hence, we determined a method to improve the resolution for a certain imaging setup. It should be noted that the resolution is not uniquely related to the degree of entanglement of the photon pair since the resolution can be optimized for a certain degree of entanglement. For certain types of Einstein-Podolsky-Rosen(EPR) states——namely the momentum-correlated or momentum-positively correlated states——the resolution exhibits a simpler relationship with the pump beam waist and crystal length. Further, a vivid numerical simulation of ghost imaging is presented for different types of EPR states,which supports our analysis. This work discusses applicable references to the applications of quantum ghost imaging.展开更多
The pulse tube refrigerator （PTR） is a promising small-scale cryocooler. This paper first briefly introduces the history of the pulse tube refrigerator. It has pointed out that technology improvements and theoretica...The pulse tube refrigerator （PTR） is a promising small-scale cryocooler. This paper first briefly introduces the history of the pulse tube refrigerator. It has pointed out that technology improvements and theoretical developments of the pulse tube refrig- erator closely relate with the internal streaming effects. Then the discovering history and classification of the streaming or DC （direct current） flow effect are summarized. It proposes for the first time that the physical significance of the streaming con- tains the driving mechanisms and the transport mechanisms. It demonstrates that the driving mechanisms are the asymmetry of fluid flow and temperature while the transport mechanisms are a loop or vorticity, which transmits nonlinear dissipations. The important advancements have been made over the past two decades all over the world in research of streaming of the pulse tube refrigerator including Gedeon DC flow, Rayleigb streaming, the third type of DC flow and the regenerator circulation. With regard to Gedeon DC flow, theoretical and experimental analyses have been made and different suppression methods are summarized. In the aspect of Rayleigh streaming, it mainly focuses on the analytical solution of the second-order mass flow and the research of tapered pulse tubes. In particular, limited research on the third type of DC flow and regenerator circulation is presented. The experimental measurement techniques of streaming also are summarized. Finally, this paper briefly discusses the key scientific and technical issues of the current research, and foretells the future development trends of streaming research in PTR.展开更多
基金Project(51778482)supported by the National Natural Science Foundation of China。
文摘Vibration-based pavement condition(roughness and obvious anomalies)monitoring has been expanding in road engineering.However,the indistinctive transverse cracking has hardly been considered.Therefore,a vehicle-based novel method is proposed for detecting the transverse cracking through signal processing techniques and support vector machine(SVM).The vibration signals of the car traveling on the transverse-cracked and the crack-free sections were subjected to signal processing in time domain,frequency domain and wavelet domain,aiming to find indices that can discriminate vibration signal between the cracked and uncracked section.These indices were used to form 8 SVM models.The model with the highest accuracy and F1-measure was preferred,consisting of features including vehicle speed,range,relative standard deviation,maximum Fourier coefficient,and wavelet coefficient.Therefore,a crack and crack-free classifier was developed.Then its feasibility was investigated by 2292 pavement sections.The detection accuracy and F1-measure are 97.25%and 85.25%,respectively.The cracking detection approach proposed in this paper and the smartphone-based detection method for IRI and other distress may form a comprehensive pavement condition survey system.
基金Project(7131109) supported the by National Defense Pre-research Foundation of ChinaProject(50975278) supported by National the Natural Science Foundation of China
文摘A novel twin-rotor piston engine （TRPE） mechanism with high volumetric output and power density was introduced. This new engine comprises an energy conversion system and a differential velocity drive mechanism （DVDM）. Two special geared four-bar mechanisms, DVDM-1 and DVDM-2, were utilized and compared. Based on the closed loop vector method, a mathematical model for position, velocity, and acceleration of the two mechanisms was established. Numerical examples illustrate that the kinematic characteristics were presented. Expression of the displacement and compression ratio of the two engine mechanisms were derived and compared. It is concluded that both DVDM-1 and DVDM-2 adopted in the proposed TRPE with six vane pistons create thirty-six power strokes per revolution of the output shaft, and the summation of two angles covered by each rocker is always 2x/N as the output shaft rotates an angle of x/N. In DVDM-1, the span angle of a vane piston should be designed to be 10.2°, and the compression ratio should be equal to 10; in DVDM-2, the span angle of a vane piston should be designed to be 10.6°, and the compression ratio should be equal to 4.3.
文摘This study investigated the difference in the levels of people＇s acceptance of robots by the types of social relationships between humans and robots. In this study, social relationships between a robot and a person were categorized into four types consisted of two in the horizontal of social relationship （intimacy dimension） and two in the vertical of social relationship （status dimension）. In dialogue between humans and robots, the types of social relationship were adjusted by forms of language such as calling by name and speech styles. People＇s acceptance of robots was measured by people＇s comfortable approach distance to the robot. Participants showed greater acceptance of a robot when the robot called them by their names. In the case of speech style, participants accepted the robot which used honorific speech style without addressing them by their name, while they accepted the robot which used familiar speech style with addressing them by their name. There was an interaction effect between gender and calling by name.
文摘Education of veterinarians in animal welfare issues is important to improve the welfare and health of animals. A questionnaire to 250 veterinarians related to their knowledge on animal welfare issues has been carried out at the Veterinary School of the University of the Republic, Uruguay, during March-April 2012. The questions were related to the courses on animal welfare veterinarians received, their main field of work, the importance given to the information offered and the quality of the topics addressed. From the total of veterinarians surveyed, 45% （112） answered the questionnaire. Of those who responded, 47% attended to three or more animal welfare courses, 18% assisted to two courses and 22% to one. The occupation of the 82% of respondents was with beef and dairy cattle （large animals） or in the meat industry equally. 10% works with small animals （especially pets） and poultry （production and industry）. The 95% of respondents considered that animal welfare is very important for their daily work with animals 65% reported that animal welfare concepts have high applicability in their job. 85% considered that animal welfare should be part of the veterinary curricula and 100% expressed their compliance to be present in other courses on the subject. These results emphasize the importance afforded by Uruguayan veterinarians to improve their knowledge on animal welfare and to continue including specific courses in the veterinary curricula.
基金supported by the National Natural Science Foundation of China(Grant Nos.11174121,11321063,91121001,and 91321312)the National Program on Key Basic Research Project(Grant No.2012CB921802)
文摘We present an analytical analysis of the spatial resolution of quantum ghost imaging implemented by entangled photons from a general, spontaneously parametric, down-conversion process. We find that the resolution is affected by both the pump beam waist and the nonlinear crystal length. Hence, we determined a method to improve the resolution for a certain imaging setup. It should be noted that the resolution is not uniquely related to the degree of entanglement of the photon pair since the resolution can be optimized for a certain degree of entanglement. For certain types of Einstein-Podolsky-Rosen(EPR) states——namely the momentum-correlated or momentum-positively correlated states——the resolution exhibits a simpler relationship with the pump beam waist and crystal length. Further, a vivid numerical simulation of ghost imaging is presented for different types of EPR states,which supports our analysis. This work discusses applicable references to the applications of quantum ghost imaging.
基金supported by the National Natural Science Foundation of China(Grant No.51176198)
文摘The pulse tube refrigerator （PTR） is a promising small-scale cryocooler. This paper first briefly introduces the history of the pulse tube refrigerator. It has pointed out that technology improvements and theoretical developments of the pulse tube refrig- erator closely relate with the internal streaming effects. Then the discovering history and classification of the streaming or DC （direct current） flow effect are summarized. It proposes for the first time that the physical significance of the streaming con- tains the driving mechanisms and the transport mechanisms. It demonstrates that the driving mechanisms are the asymmetry of fluid flow and temperature while the transport mechanisms are a loop or vorticity, which transmits nonlinear dissipations. The important advancements have been made over the past two decades all over the world in research of streaming of the pulse tube refrigerator including Gedeon DC flow, Rayleigb streaming, the third type of DC flow and the regenerator circulation. With regard to Gedeon DC flow, theoretical and experimental analyses have been made and different suppression methods are summarized. In the aspect of Rayleigh streaming, it mainly focuses on the analytical solution of the second-order mass flow and the research of tapered pulse tubes. In particular, limited research on the third type of DC flow and regenerator circulation is presented. The experimental measurement techniques of streaming also are summarized. Finally, this paper briefly discusses the key scientific and technical issues of the current research, and foretells the future development trends of streaming research in PTR.
