Optimal Sensor Configuration

Bayesian Methods for Structural Dynamics and Civil Engineering 

This depends on the sensor configuration vector in A and the chosen parameters 0 of the nominal model. The optimal sensor configuration given the nominal model is chosen as the one that minimizes this information entropy measure over all possible configurations. 

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Employment of glutamate oxidase enables the sequential assay of both transaminases without the need to coimmobilize a second enzyme. Using a glutamate oxidase sensor, Yamauchi et al. (1984) found a preincubation of the sample of 30 min to be necessary. The preincubation time could be lowered to 10 min by using an optimized sensor configuration (Wollenberger et al., 1989). 

The optimal sensor configuration, obtained by minimizing Equation (3.70), depends on the designer s choice of the nominal model determined by the nominal parameter vector 0. One way to account for the uncertainty in the nominal model is to use a prescribed PDF p(0 C) for 0. In this case, the optimal sensor configuration becomes the one that minimizes the robust information entropy Eg/lHeiAlSf, 0, C)] which is a measure of the overall uncertainty in both 0 and 0 ... 

Preliminary experiments with yttrium hydride showed increased speed and sensitivity in a simple sensor configuration. Optimization of this design, including the use of SPR, may provide the needed combination necessary for the intended safety application. Research is continuing to determine the ruggedness and durability of the hydride films. 

The design procedure allowing configuring the optimal sensor network able to detect and locate all the specified faults is carried out in four steps ... 

When molded or premolded packages cannot be used for whatever reason, for example, a need for hermetic sealing, modules using ceramic substrates (or PCB-printed circuit board) offer almost unlimited flexibility. They can be used for simple multichip modules containing two or more elements (e.g., a sensing element and an evaluation circuit), may include external components, or may be used to construct complete systems. Stress-optimized package configurations for sensitive microsystems and sensors are no problem (Fig. 5.8.4). 

The present formulation for optimal sensor placement in terms of the information entropy provides a rational procedure for comparing the uncertainty of the estimates of the parameter values for different sensor configurations. Specifically, a direct measure of the uncertainty reduction is provided by the change of the information entropy ... 

When an a priori estimate of the modal characteristics that one wishes to measure is available, e.g., from a preliminary finite element model, it is possible to estimate the optimal sensor (and actuator) configuration according to a given performance measure. As shown recently by Papadimitriou and Lombaert (2012), it is... 

Polerecky L., Burke C.S., MacCraith B.D., Optimization of absorption-based optical chemical sensors that employ a single-reflection configuration, Appl. Opt. 2002 41 2879-2887. 

The electronic circuit of the safety sensor consists of a p-type silicon electrode, an LED, a resistor, two 3 V lithium batteries, and a platinum wire as a counter electrode, connected in series, as shown in the right part of Fig. 10.7. These components are assembled in a pen-like housing, optimized to measure even thin layers of liquid on a flat surface, as shown in the left part of Fig. 10.7. This configuration is advantageous if a puddle, observed for example under a wet bench or other equipment, is to be analyzed. 

The reflecting surface can be a mirror or a membrane with a light-scattering surface. In any case, the sensor has the appearance of a monolithic probe (i.e., a dip-stick probe). Optical sensors based on absorption, fluorescence, phosphorescence, and luminescence can employ such a configuration. Various highly optimized fiberoptic probes for UV-Vis, NIR, and IR ranges are now commercially available, and their designs are shown in Fig. 9.23. 

This class of sensors is the easiest to build but prevents the development of miniaturizable sensors for in situ applications. In general, this conventional configuration represents an easy and rapid way to optimize the response characteristics of any recognition element, before any possible integration in... 

Amperometric sensors monitor current flow, at a selected, fixed potential, between the working electrode and the reference electrode. In amperometric biosensors, the two-electrode configuration is often employed. However, when operating in media of poor conductivity (hydroalcoholic solutions, organic solvents), a three-electrode system is best (29). The amperometric sensor exhibits a linear response versus the concentration of the substrate. In these enzyme electrodes, either the reactant or the product of the enzymatic reaction must be electroactive (oxidizable or reducible) at the electrode surface. Optimization of amperometric sensors, with regard to stability, low background currents, and fast electron-transfer kinetics, constitutes a complete task. 

The configuration of acoustic-wave devices, in terms of the type and geometry of transducers, as well as the electronic circuitry to which the transducers are connected, has several variations. Some of these variations are a necessary result of fundamental differences in the nature of the AW device (and the AW itself), while others are attempts to optimize particular aspects of the sensor and its response. Initially, distinction will be made between different types of AW device according to the number of ports utilized, i.e., the number of separate electrical connections (and hence the number of transducers) that each has. 

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