The Celebrated Jumping Frog of Calaveras County is Mark Twain’s first important work.Mark Twain vividly depicts life in the American West in the Gold Rush era and satires human nature,society,and politics in the stor...The Celebrated Jumping Frog of Calaveras County is Mark Twain’s first important work.Mark Twain vividly depicts life in the American West in the Gold Rush era and satires human nature,society,and politics in the story.Based on the method of stylistic analysis put forward by Leech and Short,this study aims to analyze the story through the aspects of lexical features,grammatical features,figures of speech,and cohesion and context to explore the work’s linguistic features and artistic values.展开更多
This paper presents a mechanical model of jumping robot based on the biological mechanism analysis of frog. By biological observation and kinematic analysis the frog jump is divided into take-offphase, aerial phase an...This paper presents a mechanical model of jumping robot based on the biological mechanism analysis of frog. By biological observation and kinematic analysis the frog jump is divided into take-offphase, aerial phase and landing phase. We find the similar trajectories of hindlimb joints during jump, the important effect of foot during take-off and the role of forelimb in supporting the body. Based on the observation, the frog jump is simplified and a mechanical model is put forward. The robot leg is represented by a 4-bar spring/linkage mechanism model, which has three Degrees of Freedom （DOF） at hip joint and one DOF （passive） at tarsometatarsal joint on the foot. The shoulder and elbow joints each has one DOF for the balancing function of arm. The ground reaction force of the model is analyzed and compared with that of frog during take-off. The results show that the model has the same advantages of low likelihood of premature lift-off and high efficiency as the frog. Analysis results and the model can be employed to develop and control a robot capable of mimicking the jumping behavior of frog.展开更多
文摘The Celebrated Jumping Frog of Calaveras County is Mark Twain’s first important work.Mark Twain vividly depicts life in the American West in the Gold Rush era and satires human nature,society,and politics in the story.Based on the method of stylistic analysis put forward by Leech and Short,this study aims to analyze the story through the aspects of lexical features,grammatical features,figures of speech,and cohesion and context to explore the work’s linguistic features and artistic values.
基金the National High Technology Research and Development Program of China (No.2006AA04Z245)Program for Changjiang Scholars and Innovative Research Team in University (PCSIRT) (IRT0423)
文摘This paper presents a mechanical model of jumping robot based on the biological mechanism analysis of frog. By biological observation and kinematic analysis the frog jump is divided into take-offphase, aerial phase and landing phase. We find the similar trajectories of hindlimb joints during jump, the important effect of foot during take-off and the role of forelimb in supporting the body. Based on the observation, the frog jump is simplified and a mechanical model is put forward. The robot leg is represented by a 4-bar spring/linkage mechanism model, which has three Degrees of Freedom （DOF） at hip joint and one DOF （passive） at tarsometatarsal joint on the foot. The shoulder and elbow joints each has one DOF for the balancing function of arm. The ground reaction force of the model is analyzed and compared with that of frog during take-off. The results show that the model has the same advantages of low likelihood of premature lift-off and high efficiency as the frog. Analysis results and the model can be employed to develop and control a robot capable of mimicking the jumping behavior of frog.
