Twelve Wisconsin dairy herds were selected to include six sand freestall herds and six mattress freestall herds. For the duration of one 24 hour period, the mature cow high group pen on each farm was video filmed. For each herd, the film was analyzed every hour in order to determine the number of cows in the pen that were lying down, standing in the stall with all four feet and perching in the ...

The demand for global video has been burgeoning across industries. With the expansion and improvement of videostreaming services, cloud-based video is evolving into a necessary feature of any successful business for reaching internal and external audiences. This paper considers video streaming over distributed systems where the video segments are encoded using an erasure code for better reliabi...

Rotating stalls are generally the first instability met in turbomachinery, before surges. This 3D phenomenon is characterized by one or more stalled flow cells which rotate at a fraction of the impeller speed. The goal of the present work is to shed some light on the entropy generation in a centrifugal fan under rotating stall conditions. A numerical simulation of entropy generation is carried ...

A combination of theoretical and computational nonlinear analysis techniques are used to study the scenario of bifurcations responsible for the initiation of rotating stall in an axial ow compressor model. It is found that viscosity tends to damp higher-frequency modes and so results in a sequence of bifurcations along the uniform-ow solution branch to stall cells of diierent mode number. Lower...

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A comparative study of two combined blowing/suction flow control methods was conducted on the pitching airfoil using unsteady Reynolds-averaged Navier–Stokes (URANS) method. One used leading-edge blowing and trailing-edge suction, which is referred to as a co-flow jet (CFJ), conformal slot CFJ (C-CFJ) adopted. Another suction with blowing, called reversed (R-CFJ). The S809 baseline its stall ch...

We show an application of the method of extremum seeking to the problem of maximizing the pressure rise in an axial flow compressor. First we apply extremum seeking to the Moore–Greitzer model and design a feedback scheme actuated through a bleed valve which simultaneously stabilizes rotating stall and surge and steers the system towards the equilibrium with maximal pressure. Then we implement ...

Blower and exhaust fans consume over 30% of electricity in a thermal power plant, and faults of these fans due to rotation stalls are one of the most frequent reasons for power plant outage failures. To accurately predict the occurrence of fan rotation stalls, we propose a support vector regression machine (SVRM) model that predicts the fan internal pressures during operation, leaving ample tim...

The increased number of accidents in general aviation due to loss aircraft control has necessitated the development accurate aerodynamic airplane models. These models should indicate linear variations coefficients steady flight and highly nonlinear stall post-stall conditions. This paper presents a detailed methodology model lift, drag, pitching moment regime, using Neural Networks (NN). A syst...