为了提高沉管隧道建设中抓斗船挖掘平整精度,基于实时定位动态技术(RTK)卫星定位的抓斗船的挖掘控制系统,研究出一种高平整度挖掘方法。首先,分析抓斗船施工特点,制订高平整度工艺;其次,根据抓斗挖掘位置及下放深度,针对不同抓斗建立3...为了提高沉管隧道建设中抓斗船挖掘平整精度,基于实时定位动态技术(RTK)卫星定位的抓斗船的挖掘控制系统,研究出一种高平整度挖掘方法。首先,分析抓斗船施工特点,制订高平整度工艺;其次,根据抓斗挖掘位置及下放深度,针对不同抓斗建立3种检测计算模型:平面定位模型、潮位RTK模型、抓斗计算模型。8 m 3抓斗使用平整度模型后平整度偏差由0.823 m缩小至0.190 m,大大提高了抓斗船挖掘过程中的深度精确度。展开更多
When using global positioning system/BeiDou navigation satellite(GPS/BDS)dual-mode navigation system to locate a train,Kalman filter that is used to calculate train position has to be adjusted according to the feature...When using global positioning system/BeiDou navigation satellite(GPS/BDS)dual-mode navigation system to locate a train,Kalman filter that is used to calculate train position has to be adjusted according to the features of the dual-mode observation.Due to multipath effect,positioning accuracy of present Kalman filter algorithm is really low.To solve this problem,a chaotic immune-vaccine particle swarm optimization_extended Kalman filter(CIPSO_EKF)algorithm is proposed to improve the output accuracy of the Kalman filter.By chaotic mapping and immunization,the particle swarm algorithm is first optimized,and then the optimized particle swarm algorithm is used to optimize the observation error covariance matrix.The optimal parameters are provided to the EKF,which can effectively reduce the impact of the observation value oscillation caused by multipath effect on positioning accuracy.At the same time,the train positioning results of EKF and CIPSO_EKF algorithms are compared.The eastward position errors and velocity errors show that CIPSO_EKF algorithm has faster convergence speed and higher real-time performance,which can effectively suppress interference and improve positioning accuracy.展开更多
Performance Anxiety is perhaps the most common social fear. Also called Stage Fright, Performance Anxiety is the fear of being in front of an audience, and all of the corollaries that are associated with the condition...Performance Anxiety is perhaps the most common social fear. Also called Stage Fright, Performance Anxiety is the fear of being in front of an audience, and all of the corollaries that are associated with the condition. The condition can be almost debilitating, and is all the more devastating to a seasoned professional performer who continues to be afflicted by the situation. Although there are numerous causes as the root of Performance Anxiety in different people, a significant reason for Performance Anxiety is a behavioral pattern that psychoanalysts call the Fight or Flight Syndrome. This syndrome is the focus of this paper. This paper identifies a number of the symptoms of Performance Anxiety along with many of the false antidotes that are suggested by friends and associates. Evidence is presented to support the realization that most audiences are not the enemy. Recommendations and a treatment plan are suggested which are designed to alleviate Performance Anxiety issues and are based on principles of behavioral modification.展开更多
Accurate assessment of the probability of success in an aggressive confrontation with a conspecific is critical to the survival and fitness of the individuals. Various game theory models have examined these assessment...Accurate assessment of the probability of success in an aggressive confrontation with a conspecific is critical to the survival and fitness of the individuals. Various game theory models have examined these assessment strategies under the assumption that contests should favor the animal with the greater resource-holding potential （RHP）, body size typically being the proxy. Mutual assessment asserts that an individual can assess their own RHP relative to their opponent, allowing the inferior animal the chance to flee before incurring unnecessary costs. The model of self-determined persistence, however, assumes that an individual will fight to a set personal threshold, independ- ent of their opponent＇s RHP. Both models have been repeatedly tested using size as a proxy for RHP, with neither receiving unambiguous support. Here we present both morphological and neuro- physiological data from size-matched and mismatched stalk-eyed fly fights. We discovered differ- ing fighting strategies between winners and losers. Winners readily escalated encounters to higher intensity and physical contact and engaged in less low-intensity, posturing behaviors compared with losers. Although these fighting strategies were largely independent of size, they were associ- ated with elevated levels of 5-HT. Understanding the neurophysiological factors responsible for mediating the motivational state of opponents could help resolve the inconsistencies seen in cur- rent game theory models. Therefore, we contend that current studies using only size as a proxy for RHP may be inadequate in determining the intricacies of fighting ability and that future studies investigating assessment strategies and contest outcome should include neurophysiological data.展开更多
文摘为了提高沉管隧道建设中抓斗船挖掘平整精度,基于实时定位动态技术(RTK)卫星定位的抓斗船的挖掘控制系统,研究出一种高平整度挖掘方法。首先,分析抓斗船施工特点,制订高平整度工艺;其次,根据抓斗挖掘位置及下放深度,针对不同抓斗建立3种检测计算模型:平面定位模型、潮位RTK模型、抓斗计算模型。8 m 3抓斗使用平整度模型后平整度偏差由0.823 m缩小至0.190 m,大大提高了抓斗船挖掘过程中的深度精确度。
基金National Natural Science Foundation of China(Nos.61662070,61363059)Youth Science Fund Project of Lanzhou Jiaotong University(No.2018036)。
文摘When using global positioning system/BeiDou navigation satellite(GPS/BDS)dual-mode navigation system to locate a train,Kalman filter that is used to calculate train position has to be adjusted according to the features of the dual-mode observation.Due to multipath effect,positioning accuracy of present Kalman filter algorithm is really low.To solve this problem,a chaotic immune-vaccine particle swarm optimization_extended Kalman filter(CIPSO_EKF)algorithm is proposed to improve the output accuracy of the Kalman filter.By chaotic mapping and immunization,the particle swarm algorithm is first optimized,and then the optimized particle swarm algorithm is used to optimize the observation error covariance matrix.The optimal parameters are provided to the EKF,which can effectively reduce the impact of the observation value oscillation caused by multipath effect on positioning accuracy.At the same time,the train positioning results of EKF and CIPSO_EKF algorithms are compared.The eastward position errors and velocity errors show that CIPSO_EKF algorithm has faster convergence speed and higher real-time performance,which can effectively suppress interference and improve positioning accuracy.
文摘Performance Anxiety is perhaps the most common social fear. Also called Stage Fright, Performance Anxiety is the fear of being in front of an audience, and all of the corollaries that are associated with the condition. The condition can be almost debilitating, and is all the more devastating to a seasoned professional performer who continues to be afflicted by the situation. Although there are numerous causes as the root of Performance Anxiety in different people, a significant reason for Performance Anxiety is a behavioral pattern that psychoanalysts call the Fight or Flight Syndrome. This syndrome is the focus of this paper. This paper identifies a number of the symptoms of Performance Anxiety along with many of the false antidotes that are suggested by friends and associates. Evidence is presented to support the realization that most audiences are not the enemy. Recommendations and a treatment plan are suggested which are designed to alleviate Performance Anxiety issues and are based on principles of behavioral modification.
文摘Accurate assessment of the probability of success in an aggressive confrontation with a conspecific is critical to the survival and fitness of the individuals. Various game theory models have examined these assessment strategies under the assumption that contests should favor the animal with the greater resource-holding potential （RHP）, body size typically being the proxy. Mutual assessment asserts that an individual can assess their own RHP relative to their opponent, allowing the inferior animal the chance to flee before incurring unnecessary costs. The model of self-determined persistence, however, assumes that an individual will fight to a set personal threshold, independ- ent of their opponent＇s RHP. Both models have been repeatedly tested using size as a proxy for RHP, with neither receiving unambiguous support. Here we present both morphological and neuro- physiological data from size-matched and mismatched stalk-eyed fly fights. We discovered differ- ing fighting strategies between winners and losers. Winners readily escalated encounters to higher intensity and physical contact and engaged in less low-intensity, posturing behaviors compared with losers. Although these fighting strategies were largely independent of size, they were associ- ated with elevated levels of 5-HT. Understanding the neurophysiological factors responsible for mediating the motivational state of opponents could help resolve the inconsistencies seen in cur- rent game theory models. Therefore, we contend that current studies using only size as a proxy for RHP may be inadequate in determining the intricacies of fighting ability and that future studies investigating assessment strategies and contest outcome should include neurophysiological data.
