Search results for "Sensor"
showing 10 items of 4594 documents
CiNetStrain - Wireless Strain Gauge Network - Calibration and Reliability Measurements
2013
Wireless sensor networks can be extended to include numerous different sensing devices. Strain gauges are the most common nondestructive sensing elements for measuring surface strain. This paper discusses the design, for the wireless CiNet network, of a strain gauge measurement system, which would make strain measurements more flexible while opening new targets of application in addition to those that traditional wired strain measuring systems can offer. The calibration and validation of the wireless strain measurements as well as energy consumption issues are also brought under observation.
On Distinguishing between Reliable and Unreliable Sensors Without a Knowledge of the Ground Truth
2015
In many applications, data from different sensors are aggregated in order to obtain more reliable information about the process that the sensors are monitoring. However, the quality of the aggregated information is intricately dependent on the reliability of the individual sensors. In fact, unreliable sensors will tend to report erroneous values of the ground truth, and thus degrade the quality of the fused information. Finding strategies to identify unreliable sensors can assist in having a counter-effect on their respective detrimental influences on the fusion process, and this has has been a focal concern in the literature. The purpose of this paper is to propose a solution to an extreme…
On Solving the Problem of Identifying Unreliable Sensors Without a Knowledge of the Ground Truth: The Case of Stochastic Environments.
2017
The purpose of this paper is to propose a solution to an extremely pertinent problem, namely, that of identifying unreliable sensors (in a domain of reliable and unreliable ones) without any knowledge of the ground truth. This fascinating paradox can be formulated in simple terms as trying to identify stochastic liars without any additional information about the truth. Though apparently impossible, we will show that it is feasible to solve the problem, a claim that is counterintuitive in and of itself. One aspect of our contribution is to show how redundancy can be introduced, and how it can be effectively utilized in resolving this paradox. Legacy work and the reported literature (for exam…
Multispectral, Fluorescent and Photoplethysmographic Imaging for Remote Skin Assessment
2017
Optical tissue imaging has several advantages over the routine clinical imaging methods, including non-invasiveness (does not change the structure of tissues), remote operation (avoids infection) and ability to quantify the tissue condition by means of specific image parameters. Dermatologists and other skin experts need compact (preferably pocket-size), self-sustained and easy-to-use imaging devices. The operational principles and designs of ten portable in-vivo skin imaging prototypes developed at the Biophotonics Laboratory of Institute of Atomic Physics and Spectroscopy, University of Latvia during the recent five years are presented in this paper. Four groups of imaging devices are con…
Wireless photoplethysmography finger sensor probe
2010
A sensitive, digital, wireless sensor probe has been developed for photoplethysmography (PPG) measurements. It uses standard light emitting source and detector. The main advantage of this approach is to measure discharge time of the photodiode as amplitude of PPG signal. It reduces the cost, dimensions, power consumption and filtering of the device. First results of distant monitoring of heart rate using the newly developed sensor probe are presented.
Surgical management of acute angle-closure glaucoma after toric implantable contact lens implantation
2006
A case of pupillary block after implantation of an implantable contact lens (ICL) is reported, and surgical management and prevention are discussed. In a myopic patient, the best corrected visual acuity in the right eye was 20/50 with -15.50 -3.00 x 175. After uneventful implantation of an ICL, painful acute glaucoma developed with an intraocular pressure beyond measurable values. Apparent anterior vaulting of the ICL suggested a sizing problem. In a situation of a mid-wide dilated pupil, immediate explantation of the ICL was performed. Then, using a preoperative iris photography as guidance, an anterior chamber iris-claw toric phakic intraocular lens was implanted. On postoperative examina…
Critical assessment of particle size analysis of porous silica microbead high-performance liquid chromatographic packings by photosedimentation
1979
Abstract Particle size analysis of commercial spherical silica packings of graduated pore size by means of photosedimentation (PS) is critically examined and compared to results obtained by microscopy. To avoid particle fractionation, the suspension prepared for PS measurements should be subjected to gentle ultrasonic treatment. For computing the particle size distribution, the effective density of solvent-filled porous particles has to be inserted into the Stokes equation. Reproducibility of d p , estimated by PS is found to be largely dependent upon the accuracy of the specific pore volume determination. Satisfactory agreement of data between PS and microscopy is obtained for all products…
Critical evaluation of two commonly used techniques for the treatment of data from extract dilution sniffing analysis
1993
The data from the extract dilution sniffing analysis of beer samples have been treated by two methods of analysis to give either «charm» or «FD» values. The results obtained from these two methods were compared and demonstrated that the rank order of intensity of the odor-active regions was different for most panelists when the data were presented as charm rather than FD values. Points of uncertainty observed while using this method such as between- and within-individual reproducibility and gaps in the coincident response five also been discussed
Test–retest and interobserver reliability of quantitative sensory testing according to the protocol of the German Research Network on Neuropathic Pai…
2011
Quantitative sensory testing (QST) is an instrument to assess positive and negative sensory signs, helping to identify mechanisms underlying pathologic pain conditions. In this study, we evaluated the test-retest reliability (TR-R) and the interobserver reliability (IO-R) of QST in patients with sensory disturbances of different etiologies. In 4 centres, 60 patients (37 male and 23 female, 56.4±1.9years) with lesions or diseases of the somatosensory system were included. QST comprised 13 parameters including detection and pain thresholds for thermal and mechanical stimuli. QST was performed in the clinically most affected test area and a less or unaffected control area in a morning and an a…
Heuristics and Memory Strategies Used by Mathematicians
1996
The study of the cognitive processes involved in learning and acquisition of technically complex material is a main focus of interest for basic and applied research. Our research program tries to identh memory aids and heuristic training strategies useful for improving mathematics performance. Part of the effectiveness of a course, designed by taking into account knowledge about the cognitive system, has to do with the development of an adequate relationship with the belief system of the learner. As a first step in that direction, we present a survey of the opinions of a group of mathematicians about the dd€iculty of their subjecr matter, the strategies they use spontaneously to overcome di…