Search results for "Hop"
showing 10 items of 5189 documents
New data and taxa for Orthoptera Tettigoniidae and Acrididae from tropical Africa.
2017
The results of a long-term study on the Orthoptera collected in tropical Africa and preserved in different European natural history museums are reported. Horatosphaga bazeletae n. sp. is described from South Africa, Dapanera falxcercata n. sp. from Cameroon, Eurycorypha specularia n. sp. from Zambia (Tettigoniidae Phaneropterinae), and Eucoptacra popovi n. sp. (Acrididae Coptacrinae) from the Gabon. Furthermore, the new genus Pigalua n. gen. is described for Eulioptera insularis Ragge, 1980 from Annobón Is. (Equatorial Guinea). The new tribe Kevaniellini n. trib. is proposed for Kevaniella bipunctata Chopard, 1954. Besides, the hitherto unknown males of Eurycorypha flavescens (Walker, 1869)…
Colour and luminance contrasts predict the human detection of natural stimuli in complex visual environments.
2017
Much of what we know about human colour perception has come from psychophysical studies conducted in tightly-controlled laboratory settings. An enduring challenge, however, lies in extrapolating this knowledge to the noisy conditions that characterize our actual visual experience. Here we combine statistical models of visual perception with empirical data to explore how chromatic (hue/saturation) and achromatic (luminant) information underpins the detection and classification of stimuli in a complex forest environment. The data best support a simple linear model of stimulus detection as an additive function of both luminance and saturation contrast. The strength of each predictor is modest …
Impact loading history modulates hip fracture load and location : A finite element simulation study of the proximal femur in female athletes
2018
Sideways falls impose high stress on the thin superolateral cortical bone of the femoral neck, the region regarded as a fracture-prone region of the hip. Exercise training is a natural mode of mechanical loading to make bone more robust. Exercise-induced adaptation of cortical bone along the femoral neck has been previously demonstrated. However, it is unknown whether this adaption modulates hip fracture behavior. The purpose of this study was to investigate the influence of specific exercise loading history on fall-induced hip fracture behavior by estimating fracture load and location with proximal femur finite element (FE) models created from magnetic resonance images (MRI) of 111 women w…
The use of accelerometry to evaluate the BMX cycling starting hill. Effect of the Q-Ring™ on the acceleration profile
2020
Accelerometers are becoming popular in sport performance, as they are easy to wear, affordable, and usable in the field. Eccentric chainrings have been commercialised to improve pedalling performance, but little is known about their possible effects in the first pedal strokes (PS) of maximal sprint starts. To analyse the effects of the Q-Ring chainring (Q) on pedalling mechanics and performance in the BMX starting hill, 12 Spanish-National-Team BMX athletes performed 3 maximal sprints comparing Q vs No-Q. Time was measured in the first three meters. Acceleration output was registered with a triaxial 6 g accelerometer (200 Hz) in the first four PS. Discrete time, acceleration and statistical…
Occurrence of antibiotics and antiretroviral drugs in source-separated urine, groundwater, surface water and wastewater in the peri-urban area of Chu…
2020
Recently, there has been an increased interest in bridging the knowledge gap in the occurrence and fate of pharmaceuticals in African urban water cycles. In this study, the occurrence of 7 antibiotics and 3 antiretrovirals in source-separated urine, groundwater, wastewater and surface water of the peri-urban area of Chunga in Lusaka, Zambia, was studied. In groundwater, the pharmaceuticals were only sporadically present with 4 antibiotics and 1 antiretroviral detected. The concentration of the antibiotics ranged from below limit of quantification (<LOQ) to 880 ng/L, with sulfamethoxazole having the highest detection frequency of 42.3%. In the surface water, a comparatively high concentrati…
Dynamic Response of a Rigital Displacement Motor Operating with Various Displacement Strategies
2019
Digital displacement technology has the potential of revolutionizing the performance of hydraulic piston pumps and motors. Instead of connecting each cylinder chamber to high and low pressure in conjunction with the shaft position, two electrically-controlled on/off valves are connected to each chamber. This allows for individual cylinder chamber control. Variable displacement can be achieved by using different displacement strategies, like for example the full stroke, partial stroke, or sequential partial stroke displacement strategy. Each displacement strategy has its transient and steady-state characteristics. This paper provides a detailed simulation analysis of the transient and steady…
Regenerative scheduling problem in engineer to order manufacturing: an economic assessment
2021
The dynamic production scheduling is a very complex process that may arise from the occurrence of unpredictable situations such as the arrival of new orders besides the ones already accepted. As a consequence, companies may often encounter several difficulties to make decisions about the new orders acceptance and sequencing along with the production of the existing ones. With this recognition, a mathematical programming model for the regenerative scheduling problem with deterministic processing times is formulated in the present paper to evaluate the economic advantage of accepting a new order in an engineer to order (ETO) manufacturing organization. The real case of an Italian ETO company …
Algorithmic Approach for Slot Filling Factors Determination in Electrical Machines
2018
In several industrial sectors, such as electric and hybrid traction, the demand for increasingly efficient and high power density electrical machines has grown considerably over the last few years. The improvement of slot filling factor of the electrical machines is an useful provision to satisfy this request. In particular, this topic has been the subject of interest for the industrial sector in recent years, since the technology of winding processes have evolved and allow an economically sustainable realization of windings with an ordered structure rather than randomly. The winding phase must be supported by an accurate design process in which it is possible to evaluate the maximum slot f…
Tabu Search to Plan Schedules in a Multiskill Customer Contact Center
2006
International audience; We have studied a realistic case of scheduling problem in a customer contact center, dealing with multiskill agents. Our model combines the last two steps of the standard approach by determining shifts and by assigning them to agents at the same time (scheduling and rostering). Moreover, we have considered realistic vacations, according to legal constraints and preferences of agents. We have envisioned entire weeks of work, with variable meal times and meal durations, without overtime. In this paper, we define the problem and describe a Tabu search based solution.
Debate of Ideas and Understanding With Regard to Tactical Learning in Team Sports
2021
Purpose: The researchers discuss the debate of ideas (DoI) and student understanding conducted on questioning and student answers or discussions in game-based approaches and on DoI as used in the tactical-decision learning model.Literature Review: Literature regarding types of questions and expected student answers and questioning for learning in game-based approaches is reviewed. In addition, a brief overview of the context in which DoI was originally developed is presented.Findings and Discussion: Studies that used DoI are discussed with regard to the management of game play and observation, DoI content and the dynamics of student discussions, and impact on game play statistics and on stu…