scholarly journals Using Kalman Filters to Reduce Noise from RFID Location System

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Pedro Henriques Abreu ◽  
José Xavier ◽  
Daniel Castro Silva ◽  
Luís Paulo Reis ◽  
Marcelo Petry

Nowadays, there are many technologies that support location systems involving intrusive and nonintrusive equipment and also varying in terms of precision, range, and cost. However, the developers some time neglect the noise introduced by these systems, which prevents these systems from reaching their full potential. Focused on this problem, in this research work a comparison study between three different filters was performed in order to reduce the noise introduced by a location system based on RFID UWB technology with an associated error of approximately 18 cm. To achieve this goal, a set of experiments was devised and executed using a miniature train moving at constant velocity in a scenario with two distinct shapes—linear and oval. Also, this train was equipped with a varying number of active tags. The obtained results proved that the Kalman Filter achieved better results when compared to the other two filters. Also, this filter increases the performance of the location system by 15% and 12% for the linear and oval paths respectively, when using one tag. For a multiple tags and oval shape similar results were obtained (11–13% of improvement).

Robotica ◽  
2001 ◽  
Vol 19 (2) ◽  
pp. 199-207
Author(s):  
Alvin Chua ◽  
Jayantha Katupitiya ◽  
Joris De Schutter

This paper addresses the problem of identifying the uncertainties present in a robotic contact situation. These uncertainties are errors and misalignments of an object with respect to its ideal position. The paper describes how to solve for the errors caused during grasping and errors present when coming into contact with the environment. A force sensor is used together with Kalman Filters to solve for all the uncertainties. The straightforward use of a force sensor and the Kalman Filters is found to be effective in finding only some of the uncertainties in robotic contact. The other uncertainties form dependencies that cannot be estimated in this manner. This dependency brings about the problem of observability. To make the unobservable uncertainties observable a sequence of contacts are used. The error covariance matrix of the Kalman Filter (KF) is used to obtain new contacts that are required to solve for all the uncertainties completely. There is complete freedom in choosing which unobservable quantity to be excited in forming the next contact. The paper describes how these new contacts can be randomly executed. A two dimensional contact situation will be used to demonstrate the effectiveness of the method. Experimental data are also presented to prove the validity of the procedure. Due to the non-linear relationship between the uncertainties and the forces, an Extended Kalman Filter (EKF) has been used.


Author(s):  
Mattias Henriksson ◽  
Dan Ring

This article will present that a robust Kalman filter design has a favorable property, when applied on thrust estimation on a low bypass turbofan gas turbine engine, compared to the regular Kalman filter design. This property is a larger operation range in parameters around the linearization point. On the other hand, the robust Kalman filter has marginally lower accuracy at the linearization point. This paper will present a method for describing the uncertainties in the engine model for use in the design of a robust Kalman filter. Both a regular Kalman filter and a robust Kalman filters are evaluated through simulations around a linearization point by using simulations of a nonlinear military turbofan engine.


1994 ◽  
Vol 29 (4) ◽  
pp. 127-132 ◽  
Author(s):  
Naomi Rea ◽  
George G. Ganf

Experimental results demonstrate bow small differences in depth and water regime have a significant affect on the accumulation and allocation of nutrients and biomass. Because the performance of aquatic plants depends on these factors, an understanding of their influence is essential to ensure that systems function at their full potential. The responses differed for two emergent species, indicating that within this morphological category, optimal performance will fall at different locations across a depth or water regime gradient. The performance of one species was unaffected by growth in mixture, whereas the other performed better in deep water and worse in shallow.


Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1073
Author(s):  
Claudia Campillo-Cora ◽  
Laura Rodríguez-González ◽  
Manuel Arias-Estévez ◽  
David Fernández-Calviño ◽  
Diego Soto-Gómez

Chromium is an element that possess several oxidation states and can easily pass from one to another, so its behavior in soils is very complex. For this reason, determining its fate in the environment can be difficult. In this research work we tried to determine which factors affect the chromium fractionation in natural soils, conditioning chromium mobility. We paid special attention to the parent material. For this purpose, extraction experiments were carried out on spiked soils incubated for 50–60 days, using H2O, CaCl2 and diethylenetriaminepentaacetic acid (DTPA). The most efficient extraction rate in all soils was achieved using water, followed by CaCl2 and DTPA. We obtained models with an adjusted R2 of 0.8097, 0.8471 and 0.7509 for the H2O Cr, CaCl2 Cr and DTPA Cr respectively. All models were influenced by the amount of chromium added and the parent material: amphibolite and granite influenced the amount of H2O Cr extracted, and schist affected the other two fractions (CaCl2 and DTPA). Soil texture also played an important role in the chromium extraction, as well as the amounts of exchangeable aluminum and magnesium, and the bioavailable phosphorus. We concluded that it is possible to make relatively accurate predictions of the behavior of the different Cr fractions studied, so that optimized remediation strategies for chromium-contaminated soils can be designed on the basis of a physicochemical soil characterization.


1990 ◽  
Vol 19 (1) ◽  
pp. 41-41
Author(s):  
René Lemarchand

My apologies to Mr. Chrétien and to your readers for “developing some simplistic formulas on Burundi” in my quest for “media success.” No such simplistic formulas enter his criticism of my Congressional testimony. On the one hand, I am taken to task for not conceding that my interpretation of the Hutu-Tutsi conflict as a recent phenomenon is the product of Chrétien’s “patient research work” over the last quarter of a century; on the other hand, “some very similar analysis” had appeared in my “excellent work of 1970,” which came out long before Mr. Chrétien embarked on his patient research! Try to figure that one out if you can.


Author(s):  
Abou-eisha A ◽  
Adel E El-din

Objective: The aim of this study was to investigate, for the first time, the possible in vivo genotoxic and carcinogenic activity associated with exposure to norgestrel (NGT) drug through employing the very recently established and adjusted genotoxic and tumorigenic methods in Drosophila melanogaster.Methods: Two in vivo genotoxic test systems were used; one detects the somatic mutation and recombination effects (somatic mutation and recombination test [SMART] wing-spot test) and the other detects the primary DNA damage (the comet test) in the body cells of D. melanogaster. On the other hand, the warts (wts)-based SMART assay is a vital genetic examination in Drosophila used to identify and characterize cancer potential of compounds.Results: Four experimental doses of NGT were used (ranging from 0.24 μM to 16 μM). NGT was found to be non-genotoxic at all tested concentrations even at the highest dose level 16 μM and failed to increase the frequency of tumors in the somatic cells of D. melanogaster.Conclusion: Our results strengthen the hypothesis that steroidal drugs might act through a non-genotoxic carcinogen mechanism where the carcinogenic properties occur by direct stimulation of cellular proliferation through a steroid receptor-mediated mechanism. In addition, the results obtained in this research work may contribute to highlighting the importance of NGT as a potent neuroprotective antioxidant drug.


2014 ◽  
Vol 11 ◽  
pp. 483-488
Author(s):  
Sara Cipolla

The research work concerns the development in the Italian literature of the French theme of Neuf Preux, and Particularly Took into account a crown of sonnets of nine famous men linked to an alleged cycle of paintings attributed to Giotto's in the palace of Castel Nuovo in Naples. The survey highlighted how in medieval Italian literature, beyond the more or less explicit recovery of the French literary tradition, occupies a prominent place the function that these poems take in the view of the literature of the time. The survey actually shows the two faces of the series of famous heroes, which on one hand is the mouthpiece of the political ideals and civil inspired by the courteous and Roman antiquities, on the other hand appears to be ripe fruit of a didactic poem in which the adherence to the motto of "ut pictura poesis" become as a kind of surface projection of images.


(1) It is not so long ago that it was generally believed that the "classical" hydrodynamics, as dealing with perfect fluids, was, by reason of the very limitations implied in the term "perfect," incapable of explaining many of the observed facts of fluid motion. The paradox of d'Alembert, that a solid moving through a liquid with constant velocity experienced no resultant force, was in direct contradiction with the observed facts, and, among other things, made the lift on an aeroplane wing as difficult to explain as the drag. The work of Lanchester and Prandtl, however, showed that lift could be explained if there was "circulation" round the aerofoil. Of course, in a truly perfect fluid, this circulation could not be produced—it does need viscosity to originate it—but once produced, the lift follows from the theory appropriate to perfect fluids. It has thus been found possible to explain and calculate lift by means of the classical theory, viscosity only playing a significant part in the close neighbourhood ("grenzchicht") of the solid. It is proposed to show, in the present paper, how the presence of vortices in the fluid may cause a force to act on the solid, with a component in the line of motion, and so, at least partially, explain drag. It has long been realised that a body moving through a fluid sets up a train of eddies. The formation of these needs a supply of energy, ultimately dissipated by viscosity, which qualitatively explains the resistance experienced by the solid. It will be shown that the effect of these eddies is not confined to the moment of their birth, but that, so long as they exist, the resultant of the pressure on the solid does not vanish. This idea is not absolutely new; it appears in a recent paper by W. Müller. Müller uses some results due to M. Lagally, who calculates the resultant force on an immersed solid for a general fluid motion. The result, as far as it concerns vortices, contains their velocities relative to the solid. Despite this, the term — ½ ρq 2 only was used in the pressure equation, although the other term, ρ ∂Φ / ∂t , must exist on account of the motion. (There is, by Lagally's formulæ, no force without relative motion.) The analysis in the present paper was undertaken partly to supply this omission and partly to check the result of some work upon two-dimensional potential problems in general that it is hoped to publish shortly.


1998 ◽  
pp. 43-53
Author(s):  
A. Kubicela ◽  
J. Arsenijevic ◽  
L.C. Popovic ◽  
N. Trajkovic ◽  
E. Bon

Here we have juxtaposed two distant cosmic locations of the Sun and AGN where neutral hydrogen appears in a close connection with hot coronas. Besides the solar photosphere, chromosphere and prominences where the presence of neutral hydrogen is well established, its emission quite high in hot solar corona is still puzzling. Some of earlier observations where H? emission in solar corona was detected in eclipse and in daily coronagraphic observations are reviewed. A proper theoretical explanation of this cold chromospheric-type emission in the hot corona does not exist yet. On the other side, a similar emission of hydrogen lines is present in Active Galactic Nuclei (AGNs). Much research work is currently being done in this field. We outline some of the concepts of the AGN structure prevailing in the astrophysics today.


Author(s):  
Pooja Babaso Kamble

Nadi Pariksha is the most effective diagnostic tool known in the medical field. It is cost effective,  accurate,  safe,  and gives quick results. We can conduct Nadi Pariksha on healthy individuals as well as all patients irrespective of stage of the disease also,  and even pregnant woman,  children,  elderly can undergo without any harm or side effects. However,  this technique is not being widely practised at present,  because of lack of training,  practise and knowledge about it in the present day among Ayurveda vaidyas. An iconic factor for identification of a physician,  irrespective of the time,  Region,  Nadi Pariksha can be highlighted as a common factor or even System of Medicine or Civilization of the known world. Thus,  we can perceive that Nadi Pariksha or the pulse examination remains as an effective diagnostic tool since ages. Nadi Pariksha was not been discussed among the Brihatrayees of Ayurveda. Acharya Sharangdhara was the first to document in the doctrines of Ayurveda. Thus Acharya Sharangdhara is considered as ‘The Founder of Nadi Pariksha’in Ayurveda. Nadi Pariksha was titled under the Pancha-Nidana by Acharya Sharangdhara and Ashta Sthana Pariksha by Acharya Yogaratnakara. It was the Foremost among all the other diagnostic tools mentioned by him. Later Acharyas like Acharya Bhava Mishra,  Acharya Yogaratnakara,  Acharya Basavaraja,  Acharya Kanada Maharishi,  and Acharya Ravana have contributed in giving more descriptions and importance. In the recent days Dr. Vasant lad and Dr. Sarvadeva Upadhaya’s research work interest and scope of Nadi Pariksha.


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