9 resultados para control volume
em CentAUR: Central Archive University of Reading - UK
Resumo:
We present here a straightforward method which can be used to obtain a quantitative indication of an individual research output for an academic. Different versions, selections and options are presented to enable a user to easily calculate values both for stand-alone papers and overall for the collection of outputs for a person. The procedure is particularly useful as a metric to give a quantitative indication of the research output of a person over a time window. Examples are included to show how the method works in practice and how it compares to alternative techniques.
Resumo:
FAMOUS is an ocean-atmosphere general circulation model of low resolution, capable of simulating approximately 120 years of model climate per wallclock day using current high performance computing facilities. It uses most of the same code as HadCM3, a widely used climate model of higher resolution and computational cost, and has been tuned to reproduce the same climate reasonably well. FAMOUS is useful for climate simulations where the computational cost makes the application of HadCM3 unfeasible, either because of the length of simulation or the size of the ensemble desired. We document a number of scientific and technical improvements to the original version of FAMOUS. These improvements include changes to the parameterisations of ozone and sea-ice which alleviate a significant cold bias from high northern latitudes and the upper troposphere, and the elimination of volume-averaged drifts in ocean tracers. A simple model of the marine carbon cycle has also been included. A particular goal of FAMOUS is to conduct millennial-scale paleoclimate simulations of Quaternary ice ages; to this end, a number of useful changes to the model infrastructure have been made.
Resumo:
Twenty-eight field experiments on sandy-loam soils in the UK (1982-2003) are reviewed by relating the extension of the green area duration of the flag leaf (GLADF) by fungicides to effects on yield and quality of winter wheat. Over all experiments mean grain yield = 8.85t ha(-1) at 85% DM. With regards quality, mean values were: thousand grain weight (TGW) = 44.5 g; specific weight (SWT) = 76.9 kg hl(-1); crude protein concentration (CP (N x 5.7)) = 12.5 % DM; Hagberg falling number (HFN) = 285 s; and sodium dodecyl sulphate (SDS)-sedimentation volume = 69ml. For each day (d) that fungicides increased GLADF there were associated average increases in yield (0.144 1 ha(-1) d(-1), se 0.0049, df = 333), TGW (0.56 gd(-1), se = 0.017) and SWT (0.22 kg hl(-1) d(-1), se 0.011). Some curvature was evident in all these relationships. When GLADF was delayed beyond 700 degrees Cd after anthesis, as was possible in cool wet seasons, responses were curtailed, or less reliable. Despite this apparent terminal sink limitation, fungicide effects on sink size, eg endosperm cell numbers or maximum water mass per grain, were not prerequisites for large effects on grain yield, TGW or SWT. Fungicide effects on CP were variable. Although the average response of CP was negative (-0.029%DM/d; se = 0.00338), this depended on cultivar and disease controlled. Controlling biotrophs such as rusts, (Puccinia spp.) tended to increase CP, whereas controlling a more necrotrophic pathogen (Septoria tritici) usually reducedCP. Irrespective of pathogen controlled, delaying senescence of the flag leaf was associated with increased nitrogen yields in the grain (averaging 2.24 kg N ha-1 d(-1), se = 0.0848) due to both increased N uptake into the above ground crop, and also more efficient remobilisation of N from leaf laminas. When sulphur availability appeared to be adequate, fungicide x cultivar interactions were similar on S as for CP, although N:S ratios tended to decline (i.e. improve for bread making) when S. tritici was controlled. On average, SDS-sedimentation volume declined (-0. 18 ml/d, se = 0.027) with increased GLADF, broadly commensurate with the average effect on CP. Hagberg falling number decreased as fungicide increased GLADF (-2.73 s/d, se = 0.178), indicating an increase in alpha-amylase activity.
Resumo:
Haptic interfaces can provide highly realistic interaction with objects within their workspace, but the task of interacting with objects over large areas or volumes is made difficult by the limits of interface travel. This paper details the development of a custom haptic interface - for navigating a large virtual environment (a simulated supermarket), and investigation into different control methods which allow for haptic interaction over extremely large workspaces.
Resumo:
Objectives. Theoretic modeling and experimental studies suggest that functional electrical stimulation (FES) can improve trunk balance in spinal cord injured subjects. This can have a positive impact on daily life, increasing the volume of bimanual workspace, improving sitting posture, and wheelchair propulsion. A closed loop controller for the stimulation is desirable, as it can potentially decrease muscle fatigue and offer better rejection to disturbances. This paper proposes a biomechanical model of the human trunk, and a procedure for its identification, to be used for the future development of FES controllers. The advantage over previous models resides in the simplicity of the solution proposed, which makes it possible to identify the model just before a stimulation session ( taking into account the variability of the muscle response to the FES). Materials and Methods. The structure of the model is based on previous research on FES and muscle physiology. Some details could not be inferred from previous studies, and were determined from experimental data. Experiments with a paraplegic volunteer were conducted in order to measure the moments exerted by the trunk-passive tissues and artificially stimulated muscles. Data for model identification and validation also were collected. Results. Using the proposed structure and identification procedure, the model could adequately reproduce the moments exerted during the experiments. The study reveals that the stimulated trunk extensors can exert maximal moment when the trunk is in the upright position. In contrast, previous studies show that able-bodied subjects can exert maximal trunk extension when flexed forward. Conclusions. The proposed model and identification procedure are a successful first step toward the development of a model-based controller for trunk FES. The model also gives information on the trunk in unique conditions, normally not observable in able-bodied subjects (ie, subject only to extensor muscles contraction).
Resumo:
This volume is based upon the 2nd IEEE European Workshop on Computer-Intensive Methods in Control and Signal Processing, held in Prague, August 1996.
Resumo:
This volume is based on a seminar concerned with advanced methods in adaptive control for industrial applications which was held in Prague in May 1990 and which brought together experts in the UK and Czechoslovakia in order to suggest solutions to specific current and anticipated problems faced by industry.
Resumo:
Paraplegic subjects lack trunk stability due to the loss of voluntary muscle control.This leads to a restriction of the volume of bi-manual workspace available,and hence has a detrimental impact on activities of daily living. Electrical Stimulation of paralysed muscles can be used to stabilize the trunk, but has never been applied in closed loop for this purpose. This paper describes the development of two closed loop controllers(PID and LQR),and their experimental evaluation on a human subject. Advantages and disadvantages of the two are discussed,considering a potential use of this technology during daily activities.
Resumo:
Infection with Eimeria spp. (coccidia) can be devastating in goats, particularly for young, recently-weaned kids, resulting in diarrhea, dehydration, and even death. Feeding dried sericea lespedeza [SL; Lespedeza cuneata (Dum.-Cours.) G. Don.] to young goats has been reported to reduce the effects of internal parasites, including gastrointestinal nematodes (GIN) but there have been no reports of the effects of feeding this forage on Eimeria spp. in goats. Two confinement feeding experiments were completed on recently-weaned intact bucks (24 Kiko-cross, Exp. 1; 20 Spanish, Exp. 2) to determine effects of SL pellets on an established infection of GIN and coccidia. The bucks were assigned to 1 of 2 (Exp. 1) or 3 (Exp. 2) treatment groups based upon the number of Eimeria spp. oocysts per gram (OPG) of feces. In Exp. 1, the kids were fed 1 of 2 pelleted rations ad libitum; 90% SL leaf meal + 10% of a liquid molasses/lignin binder mix and a commercial pellet with 12% crude protein (CP) and 24% acid detergent fiber (n = 12/treatment group, 2 animals/pen). For Exp. 2, treatment groups were fed 1) 90% SL leaf meal pellets from leaves stored 3 years (n = 7), 2) 90% SL pellets from leaf meal stored less than 6 months, (n = 7), and the commercial pellets (n = 6) ad libitum. For both trials, fecal and blood samples were taken from individual animals every 7 days for 28 days to determine OPG and GIN eggs per gram (EPG) and packed cell volume (PCV), respectively. In Exp. 2, feces were scored for consistency (1 = solid pellets, 5 = slurry) as an indicator of coccidiosis. In Exp. 1, EPG (P < 0.001) and OPG (P < 0.01) were reduced by 78.7 and 96.9%, respectively, 7 days after initiation of feeding in goats on the SL pellet diet compared with animals fed the control pellets. The OPG and EPG remained lower in treatment than control animals until the end of the trial. In Exp. 2, goats fed new and old SL leaf meal pellets had 66.2 and 79.2% lower (P < 0.05) EPG and 92.2 and 91.2% lower (P < 0.05) OPG, respectively, than control animals within 7 days, and these differences were maintained or increased throughout the trial. After 4 weeks of pellet feeding in Exp. 2, fecal scores were lower (P < 0.01) in both SL-fed groups compared with control animals, indicating fewer signs of coccidiosis. There was no effect of diet on PCV values throughout either experiment. Dried, pelleted SL has excellent potential as a natural anti-coccidial feed for weaned goats.