Feasibility Study on Stability of Gait Patterns with Changeable Body Stiffness Using Pneumatic Actuators in a Quadruped Robot

An oscillator-type gait controller for a quadruped robot with antagonistic pairs of pneumatic actuators is proposed. By using the controller, a feasibility study on the stability of gait patterns with changeable body stiffness is reported. The periodic motions of the legs are generated and controlled by an oscillator network with state resetting. This type of controller has robustness in its gaits against variation in walking conditions or changes of environment. However, it sometimes loses robustness under conditions of actuation delay, decrease of actuator accuracy, etc. We investigated whether an oscillator-type controller with phase resetting is also effective under such conditions. The stability of locomotion also strongly depends on the mechanical properties of the body mechanism, especially the joint stiffness. In this report, the muscle tone of the robot on the pitching motion at the trunk is changeable by using the changeable elasticity of the pneumatic actuators. The stability of quadruped locomotion in walk and trot patterns with changeable body stiffness was evaluated with numerical simulations and hardware experiments.     

S1240 EC7.4版本中TONE-BUS录音通知功能的分析

针对S1240交换机EC7.4版本的录音通知功能,对录音通知以TONEBUS方式在本交换局内和在交换局间两种不同情况下传送的工作原理进行了详细的分析,并结合参考实例介绍了新的录音通知建立的过程。     

基于逻辑回归模型的中文垃圾短信过滤

设计并实现中文垃圾短信过滤器,能够较好识别不断变化的垃圾短信。以逻辑回归模型为基础,提出字节级n元文法提取短信特征,并采用TONE（Train On or Near Error）方法训练过滤器。通过实验测试,证明应用该方法实现的垃圾短信过滤效果很好。     

Neurobiological Basis of Controlling Posture and Locomotion

Posture and movements are our only physical means of interacting with the environment. As we express our thoughts and emotions through posture and movements, they indicate our will or intentions. Locomotion is representative of purposeful goal-directed behaviors that are initiated by signals arising from either volitional processing in the cerebral cortex or emotional processing in the limbic system. Regardless of whether the locomotion is volitional or emotional, it is accompanied by automatically controlled movement processes such as the adjustment of postural muscle tone and rhythmic limb movements that are unconsciously executed. Sensori-motor integration at the level of the brainstem and spinal cord plays major roles in this automatic control. Signals processed in the basal ganglia and the cerebellum act on the cerebral cortex, the limbic system and the brainstem so that locomotor behaviors are appropriately and precisely regulated depending on the behavioral context. The purpose of this review is to describe how purposeful locomotor behaviors are initiated, executed and regulated so as to enable locomotive subjects to interact with and adapt to the environment.     

高性能中文垃圾邮件过滤器

设计并实现了基于在线过滤模式高性能中文垃圾邮件过滤器,能够较好地识别不断变化的垃圾邮件。以逻辑回归模型为基础,该文提出了字节级n元文法提取邮件特征,并采用TONE(Train On or Near Error)方法训练过滤器。在多个大规模中文垃圾邮件过滤公开评测数据上的实验结果表明,该文过滤器的性能在TREC 06C数据上优于当年评测的最好成绩,在SEWM 07立即反馈上1-ROCA值达到了0.000 0%,并明显优于SEWM 08评测在线过滤任务中的所有其他方法。