Widely dispersed monitoring networks generate huge data volumes that are naturally organized via hierarchical aggregation. In a system that manages such data, applications pose periodic aggregate queries. In this paper we show how to efficiently process multiple periodic aggregate queries in a hierarchy. First, we use a novel query rewrite that optimally executes individual queries. Next, we sh...

A flotation bank is a serial arrangement of cells. How to optimally operate a bank remains a challenge. This article reviews three reported strategies: air profiling, mass-pull (froth velocity) profiling and Peak Air Recovery (PAR) profiling. These are all ways of manipulating the recovery profile down a bank, which may be the property being exploited. Mathematical analysis has shown that a fla...

epoxy powder coatings containing zinc aluminum phosphate (zap) and zinc phosphate (zp), which are the 2nd and 1st generation of phosphate-based pigments respectively, were applied to the surface of mild steel sheets. the anticorrosive performances of the coated samples were studied using electrochemical impedance spectroscopy (eis). cathodic disbonding resistance and the adhesion performance of...

this paper studies pull-in behavior of a bio-mass sensor with a cantilevered cnt actuated electrostatically considering rippling deformation. although this phenomenon can change the behavior of cnt remarkably, its effect on the performance of a cnt-based mass sensor is not investigated yet. this investigation is based on modified euler-bernoulli beam theory and rippling effect is entered the eq...

A novel single-stage push–pull electronic ballast with high input power factor is presented in this paper. The proposed electronic ballast combines the front-end power-factor corrector and push–pull converter into a single-stage converter. Compared to the single-stage class-D electronic ballast, the proposed circuit does not require an isolated driver. The control of the circuit is easier and t...

Accurate determination of the pull-in, or the collapse voltage is critical in the design process. In this paper an analytical method is presented that provides a more accurate determination of the pull-in voltage for MEMS capacitive devices with clamped square diaphragm. The method incorporates both the linearized modle of the electrostatic force and the nonlinear deflection model of a clamped ...

in the current study the effect of casimir force and squeezed film damping on the pull-in instability and dynamic behavior of electrostatically actuated nano and micro electromechanical systems is investigated separately. linear elastic membrane theory is used to model the static and dynamic behavior of system for strip, annular and disk geometries. squeezed film damping effect is modeled using...

The dielectric charging constitutes a major problem that still inhibits the commercial application of RF MEMS capacitive switches. The effect arises from the presence of the dielectric film (Fig.1a), which limits the displacement of the suspended electrode and determines the device pull-down state capacitance. Macroscopically, the dielectric charging is manifested through the shift (Fig.1b) (Re...