f q A method is described for reducing the visibility of artifacts arising in the display o uantized color images on CRT displays. The method is based on the differential spatial senv sitivity of the human visual system to chromatic and achromatic modulations. Because the isual system has the highest spatial and temporal acuity for the luminance component of an i image, we seek a technique whic...

System development methods have already long been controversially discussed, but there is still a lack of knowledge and understanding based on empirical studies about how systems development is actually conducted in practice, how system development methodologies and methods are used and to what degree they are used as proposed in the literature (Floyd, 1986; Nandhakumar & Avison, 1999). The pur...

The Void-and-Cluster method for producing ordered dither arrays is powerful in its simplicity and flexibility. Central to the method is the voidand cluster-finding filter. This paper explores the use of a gaussian filter, and in particular, the effect of the gaussian parameter σ on image quality. Excellent isotropic bluenoise dithering can be achieved with a σ between 1.0 and 1.5 with relativel...

Many cellular processes involve a small number of molecules and undergo stochastic fluctuations in their levels of activity. Cerebellar long-term depression (LTD) is a form of synaptic plasticity expressed as a reduction in the number of synaptic AMPA receptors (AMPARs) in Purkinje cells. We developed a stochastic model of the LTD signaling network, including a PKC-ERK-cPLA(2) positive feedback...

This thesis proposes a new maximum power point tracking (MPPT) method for photovoltaic (PV) systems using Kalman filter. The Perturbation & Observation (P&O) method is widely used due to its easy implementation and simplicity. The P&O usually requires a dithering scheme to reduce noise effects, but the dithering scheme slows the tracking response time. Tracking speed is the most important facto...

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With high sensitivity imaging arrays, accurate calibration is essential to achieve the limits of detection of space observatories. One can simultaneously extract information about the scene being observed and the calibration properties of the detector and imaging system from redundant dithered images of a scene. There are large differences in the effectiveness of dithering strategies for allowi...

Active vision techniques use programmable light sources, such as projectors, whose intensities can be controlled over space and time. We present a broad framework for fast active vision using Digital Light Processing (DLP) projectors. The digital micromirror array (DMD) in a DLP projector is capable of switching mirrors “on” and “off” at high speeds (10/s). An off-the-shelf DLP projector, howev...

PURPOSE To develop an active MR-tracking system to guide placement of metallic devices for radiation therapy. METHODS An actively tracked metallic stylet for brachytherapy was constructed by adding printed-circuit micro-coils to a commercial stylet. The coil design was optimized by electromagnetic simulation, and has a radio-frequency lobe pattern extending ∼5 mm beyond the strong B0 inhomoge...

Dithering quality of the void and cluster algorithm suffers due to fixed filter width and absence of a well-defined criterion for selecting among equally likely candidates during the computation of the locations of the tightest clusters and largest voids. Various researchers have addressed the issue of fixed filter width by adaptively changing the width with experimentally determined values. Th...