An edge detection scheme is developed robust enough to perform well over a wide range of signal-to-noise ratios. It is based upon the detection of zero crossings in the output image of a nonlinear Laplace filter. Specific characterizations of the nonlinear Laplacian are its adaptive orientation to the direction of the gradient and its inherent masks which permit the develop ment of approximatel...

We study the minimum total weighted completion time problem P | | wjCj , which is known to be stronglyNP-hard. We analyze a simple local search heuristic, moving jobs from one machine to another. The local optima can be shown to be approximately optimal with approximation ratio 32 . In case all jobs have equal weight to processing time ratios, the approximation ratio is at most 3 2 − 1 6 .

We describe a method of using a Lagrange multiplier to make a locally optimal trade off between rate and distortion in the motion search for video sequences, while maintaining a constant bit rate channel. Simulation of this method shows that it gives up to 3.5 dB PSNR improvement in a high motion sequence. A locally rate-distortion (R-D) optimal mode selection mechanism is also described. This ...

Given a planar point set, we consider three classes of optimal triangulations: (1) the minimum weight triangulation with angular constraints (constraints on the minimum angle and the maximum angle in a triangulation), (2) the angular balanced triangulation which minimizes the sum of the ratios of the maximum angle to the minimum angle for each triangle, and (3) the area balanced triangulation w...

This paper investigates the detection performance of an improved energy detector for a secondary user with spatially correlated multiple antennas. In an improved energy detector, an arbitrary positive power operation p replaces the squaring operation in a conventional energy detector, and the optimum value of p that gives the best detection performance may be different from 2. Firstly, for a gi...

The Taguchi design of experiments was used to test the relative importance of medium components and environmental factors on poly(β-hydroxybutyrate)(PHB) production by Ralstonia eutropha. The optimum condition was obtained as: fructose concentration, 15 g/L; C/N ratio, 7.4; agitation speed 200 rpm; culture time, 40 h; temperature, 25 ° C; seed age, 15 h. At optimu...

background: we investigated whether the lungheart ratio parameter (lhr) can be used to identify the optimum cut off frequency for butterworth filter in 99mtc myocardial spect imaging. materials and methods: this study involved a cardiac phantom system consisting of cardiac insert in which 1.10 cm cold defect was inserted into its myocardium wall and filled with 4.0 μci/ml (0.148 mbq/ml) 99mtc c...

This study presents the synthesis of polyvinyl acetate (PVAc) by solution polymerization and its partial hydrolysis to polyvinyl alcohol (PVA) using alkaline alcoholysis. The influence of the molar ratio of hydrolysis catalyst (NaOH) to PVAc and the time and temperature of the saponification reaction on the degree of hydrolysis and molecular weight of the PVA were investigated using response su...

In this study, various percentage of DEE was added to the optimum selected ethanol-diesel blend (D-E10) and optimized its blending ratio to overcome the poor ignition quality of ethanol when utilized in a single cylinder DI diesel engine. Some physicochemical properties of test fuels such as heating value, viscosity, and density and distillation profile were determined in accordance to the A...