An agricultural implement for underground application of rodenticide bait to control the Mediterranean pocket gopher (Microtus Duodecimcostatus) in fruit orchards has been designed and tested. The main objective of this research was to design and test the implement by using the finite element method (FEM) and considering a range of loads generated on most commonly used furrow openers in agricul...

We study the dynamics of a rigid, symmetric wing that is flapped vertically in a fluid. The motion of the wing in the horizontal direction is not constrained. Above a critical flapping frequency, forward flight arises as the wing accelerates to a terminal state of constant speed. We describe a number of measurements which supplement our previous work. These include a a study of the initial tran...

The quality-control method is improved and used to identify accident black spots on highway. A neural networks prediction model based on three layers BP network is suggested to predict road traffic accident. The dynamic accident power method for macroscopic evaluation is put forward and the concept of highway accident coefficient is advanced in the method. With large numbers of actual traffic a...

An improved PID friction feed-forward compensation control based on segment friction model is presented for nonlinear friction perturbation problems of high precision optoelectronic tracking stable platform systems. From the view of engineering application, the friction characteristics of stable platform servo systems are considered, a simple and reasonable segment friction model is established...

Running speed is limited by a mechanical interaction between the stance and swing phases of the stride. Here, we tested whether stance phase limitations are imposed by ground force maximums or foot-ground contact time minimums. We selected one-legged hopping and backward running as experimental contrasts to forward running and had seven athletic subjects complete progressive discontinuous tread...

Backward running has long been used in sports conditioning programs and has recently been incorporated into rehabilitative settings as a method of increasing quadriceps strength while decreasing the joint compressive forces about the knee. Although backward locomotion has been studied kinetically, the metabolic cost of backward walking and/or running has not to our knowledge been previously cha...

Wing and body kinematics of free cruising flight are described for 37 species of Panamanian butterflies ranging over two orders of magnitude in body mass. Butterflies exhibit considerable diversity in body and wing shape, but morphological design is, in general, isometric. Wing loading and mean body diameter show positive allometry. The cruising flight of butterflies is characterized by low win...

Groups of fixed-wing robots can benefit from moving in synchrony to share sensing and communication capabilities, avoid collisions or produce visually pleasing choreographies. Synchronous motion is especially challenging when using fixed-wing robots that require continuous forward motion to fly. For such platforms, performing trajectories with forward speed lower than the minimum speed of the r...

Caudo-rostral whole-field visual motion elicits forward locomotion in many organisms, including larval zebrafish. Here, we investigate the dependence on the latency to initiate this forward swimming as a function of the speed of the visual motion. We show that latency is highly dependent on speed for slow speeds (<10 mm s(-1)) and then plateaus for higher values. Typical latencies are >1.5 s, w...

PURPOSE This study aimed to determine the eye movement parameter(s) that is primarily affected when fully sighted subjects use plus-lens magnifiers for reading. METHODS Two forms of plus-lens magnifier were used: hand-held and spectacle-mounted. Eye movements were recorded using an infrared limbal reflection system as subjects read passages of text with and without the magnifiers. Data were c...