This paper handles a trajectory optimization of fixed wing aircraft perch landing assisted by thruster. The paper develops aircraft model and deals with six-degree-of-freedom motion for further understanding of dynamic phenomena of proposed landing method. The landing maneuver is described as an optimal control problem minimizing the fuel consumption with specified terminal landing conditions. ...

purpose: to evaluate corneal hysteresis and corneal resistance factor in penetrating keratoplasty grafts in a group of keratoconic eyes using the ocular response analyzer (ora) and to evaluate the relationship between donor size, donor-recipient disparity and central graft thickness (cgt), and ora parameters. methods: this cross-sectional study was conducted on 34 eyes of 34 keratoconus patient...

background and objectives: it has been shown that a bout of jumping exercise with weighted vests increases the subsequent countermovement jump height. however, it is not clear whether the improvement in jump height is due to the enhancement of joint power or due to other mechanisms such as neural adaptations. methods: to investigate this dichotomy, we tested the acute neuromechanical changes fo...

charm. In the summer of 1685, James II overcame invasions in the north and in the south. The invasion in the south had been led by the Duke of Monmouth, illegitimate son of Charles the second. Monmouth had landed in Dorset and had been immediately proclaimed King by his supporters. He had, however, obtained no following in Bristol or in Wiltshire. Monmouth was defeated in a battle at Sedgemoor ...

Large number of studies showed that landing with great impact forces may be a risk factor for knee injuries. The purpose of this study was to illustrate the different landing loads to lower extremity of both genders and examine the relationships among selected lower extremity kinematics and kinetics during the landing of a stop-jump task. A total of 35 male and 35 female healthy subjects were r...

[Purpose] The purpose of this study was to assess the sagittal angles and moments of lower extremity joints during single-leg jump landing in various directions. [Subjects] Eighteen male athletes participated in the study. [Methods] Participants were asked to perform single-leg jump-landing tests in four directions. Angles and net joint moments of lower extremity joints in the sagittal plane we...

Helicopter landing sites in proximity to the forest fire-risk zones are necessary for the delivery of supplies and fire emergency response teams. In this paper, we initially prepared forest fire risk map using Random Forest algorithm by overlaying the effective factors on fire occurring including vegetation types, physiographic, climatic and human factors. Then, three variants of natural candid...

It is common practice to study jump landing mechanics by having subjects step off a box set at a certain height instead of landing from a jump. This practice assumes that the landing mechanics are similar between stepping off a box and a countermovement jump as long as the heights can be matched. The mechanics of the two methods had never been compared when landing from identical heights. Thus,...

During jumping or falling in humans and various other mammals, limb muscles are activated before landing, and the intensity and timing of this pre-landing activity are scaled to the expected impact. In this study, we test whether similarly tuned anticipatory muscle activity is present in hopping cane toads. Toads use their forelimbs for landing, and we analysed pre-landing electromyographic (EM...