51 research outputs found
Method development and implementation of PFAS analysis using HPLC-QQQ
No full textAuthor Elmir Velagic, BScMasterarbeit Johannes Kepler Universität Linz 202
Method development and implementation of PFAS analysis using HPLC-QQQ
No full textAuthor Elmir Velagic, BScMasterarbeit Johannes Kepler Universität Linz 202
Semi-Automated 3D Registration for Heterogeneous Unmanned Robots Based on Scale Invariant Method
No full textThis paper addresses the problem of 3D registration of outdoor environments combining heterogeneous datasets acquired from unmanned aerial (UAV) and ground (UGV) vehicles. In order to solve this problem, we introduced a novel Scale Invariant Registration Method (SIRM) for semi-automated registration of 3D point clouds. The method is capable of coping with an arbitrary scale difference between the point clouds, without any information about their initial position and orientation. Furthermore, the SIRM does not require having a good initial overlap between two heterogeneous datasets. Our method strikes an elegant balance between the existing fully automated 3D registration systems (which often fail in the case of heterogeneous datasets and harsh outdoor environments) and fully manual registration approaches (which are labour-intensive). The experimental validation of the proposed 3D heterogeneous registration system was performed on large-scale datasets representing unstructured and harsh outdoor environments, demonstrating the potential and benefits of the proposed 3D registration system in real-world environments
3D registration and integrated segmentation framework for heterogeneous unmanned robotic systems
No full textThe paper proposes a novel framework for registering and segmenting 3D point clouds of large-scale natural terrain and complex environments coming from a multisensor heterogeneous robotics system, consisting of unmanned aerial and ground vehicles. This framework involves data acquisition and pre-processing, 3D heterogeneous registration and integrated multi-sensor based segmentation modules. The first module provides robust and accurate homogeneous registrations of 3D environmental models based on sensors' measurements acquired from the ground (UGV) and aerial (UAV) robots. For 3D UGV registration, we proposed a novel local minima escape ICP (LME-ICP) method, which is based on the well known iterative closest point (ICP) algorithm extending it by the introduction of our local minima estimation and local minima escape mechanisms. It did not require any prior known pose estimation information acquired from sensing systems like odometry, global positioning system (GPS), or inertial measurement units (IMU). The 3D UAV registration has been performed using the Structure from Motion (SfM) approach. In order to improve and speed up the process of outliers removal for large-scale outdoor environments, we introduced the Fast Cluster Statistical Outlier Removal (FCSOR) method. This method was used to filter out the noise and to downsample the input data, which will spare computational and memory resources for further processing steps. Then, we co-registered a point cloud acquired from a laser ranger (UGV) and a point cloud generated from images (UAV) generated by the SfM method. The 3D heterogeneous module consists of a semi-automated 3D scan registration system, developed with the aim to overcome the shortcomings of the existing fully automated 3D registration approaches. This semi-automated registration system is based on the novel Scale Invariant Registration Method (SIRM). The SIRM provides the initial scaling between two heterogenous point clouds and provides an adaptive mechanism for tuning the mean scale, based on the difference between two consecutive estimated point clouds' alignment error values. Once aligned, the resulting homogeneous ground-aerial point cloud is further processed by a segmentation module. For this purpose, we have proposed a system for integrated multi-sensor based segmentation of 3D point clouds. This system followed a two steps sequence: ground-object segmentation and color-based region-growing segmentation. The experimental validation of the proposed 3D heterogeneous registration and integrated segmentation framework was performed on large-scale datasets representing unstructured outdoor environments, demonstrating the potential and benefits of the proposed semi-automated 3D registration system in real-world environments
Partial characterization of the antilisterial action excerted by <em>Pichia norvegensis</em> and <em>Staphylococcus equorum</em>
No full textOberflächengereifte Rotschmierekäse weisen eine hohe Kontaminationshäufigkeit mit Listeria monocytogenes auf. Als mögliche Bestandteile einer antilisteriellen Reifungs-/Schutzkultur kämen Hefen und Staphylokokken in Frage. Ihr antilisterieller Wirkmechanismus wurde vor einem möglichen Einsatz näher untersucht. Die listerizide Wirkung von P. norvegensis WSYC 592 konnte bei Cokultivierung mit L. monocytogenes beobachtet werden, blieb jedoch aus, wenn der zellfreie Hefeüberstand zum Einsatz kam. P. norvegensis könnte eine oder mehrere unstabile antilisterielle Substanzen produzieren, die zur Inhibierung der Listerien fortwährend synthetisiert werden müssen. Staphylococcus equorum WS 4524 produziert eine gegenüber Hitze und proteolytischen Enzymen stabile Substanz. Daneben deutet der Nachweis eines Peptidsynthetasegens auf das bereits bekanntes Peptidantibiotikum Micrococcin P1 hin.Smear-ripened cheeses are frequently contaminated with Listeria monocytogenes. The establishment of defined ripening/protective cultures containing antilisterial yeasts and staphylococci would be ideal. For a commercial application, it is of major importance to identify the substance responsible for the antilisterial activity. The antilisterial activity of the P. norvegensis strain WSYC 592 was only observed when the yeast strain and L. monocytogenes grew in a co-culture. Various experiments using the cell-free yeast culture supernatant did not show any inhibitory activity at all. It is likely that P. norvegensis produces one or more unstable antilisterial substances that have to be synthesized constantly in order to inhibit Listeria. The Staphylococcus equorum strain WS 4524 produces an antilisterial substance that is stable against heat and enzymes. Furthermore, the presence of a peptide synthetase gene indicates similarity to Micrococcin P1, a well-known peptide antibiotic
Extrapolation-based approach to optimization with constraints determined by the Robin boundary problem for the Laplace equation
No full textThis paper considers the application of extrapolation techniques in finding approximate solutions of some optimization problems with constraints defined by the Robin boundary problem for the Laplace equation. When applied extrapolation techniques produce very accurate solutions of the boundary problems on relatively coarse meshes, but this paper demonstrates that this is not a real restriction when dealing with optimization problems. Producing a solution of continuous problem by polynomial extrapolation based on the low-order discrete problem solutions significantly reduces both computational time and memory. The present paper illustrates this approach using finite-difference and finite-element methods, and finally makes a brief remark about some tacit engineering assumptions regarding numerical solutions of conductive media problems by construction of equivalent resistor networks.</p
Extrapolation-based approach to optimization with constraints determined by the Robin boundary problem for the Laplace equation
No full textThis paper considers the application of extrapolation techniques in finding approximate solutions of some optimization problems with constraints defined by the Robin boundary problem for the Laplace equation. When applied extrapolation techniques produce very accurate solutions of the boundary problems on relatively coarse meshes, but this paper demonstrates that this is not a real restriction when dealing with optimization problems. Producing a solution of continuous problem by polynomial extrapolation based on the low-order discrete problem solutions significantly reduces both computational time and memory. The present paper illustrates this approach using finite-difference and finite-element methods, and finally makes a brief remark about some tacit engineering assumptions regarding numerical solutions of conductive media problems by construction of equivalent resistor networks.</p
An Orthogonal ARX Network for Identification and Control of Nonlinear Systems
No full text22nd International Symposium on Information Communication and Automation Technologies -- OCT 29-31, 2009 -- Sarajevo, BOSNIA & HERCEGThis paper presents a new orthogonal neural network (ONN) which is utilized successively for online identification and control of nonlinear discrete-time systems. The proposed network is designed with auto regressive with exogenous (ARX) terms of inputs and outputs, and their orthogonal terms by Chebyshev polynomials. The network is a single layer neural network and computationally efficient with less number of parameters. The identification by the network is performed in stable sense by using Lyapunov stability guaranteed learning rate. Hence, the learning rate depends on the current knowledge of the system instead of using constant learning rate. This learning rate provides fine online optimization. In simulation study, one benchmark nonlinear system is identified and results are compared. Then, one nonlinear functioned system is identified and controlled by model reference control. From results, it is seen that the proposed model has good learning capability for identification and control.IEEE, Control Sys Soc, ACM Soc, ACM/SIGGRAPH, IEEE, IEEE Bosnia Herzegovina Sect, Missouri State Uni
Nitric oxide resistance, induced in the myocardium by diabetes, is circumvented by the nitric oxide redox sibling, nitroxyl
No full textAim: Impairment of tissue responsiveness to exogenous and endogenous nitric oxide (NO•), known as NO• resistance, occurs in many cardiovascular disease states, prominently in diabetes and especially in the presence of marked hyperglycemia. In this study, we sought to determine in moderate and severe diabetes (i) whether NO• resistance also occurs in the myocardium, and (ii) whether the NO• redox sibling nitroxyl (HNO) circumvents this. Results: The spectrum of acute NO• effects (induced by diethylamine-NONOate), including vasodilation, and enhanced myocardial contraction and relaxation were impaired by moderately diabetic rats ([blood glucose] ∼20 mM). In contrast, acute HNO effects (induced by isopropylamine-NONOate) were preserved even in more severe diabetes ([blood glucose] >28 mM). Intriguingly, the positive inotropic effects of HNO were significantly enhanced in diabetic rat hearts. Further, progressive attenuation of soluble guanylyl cyclase (sGC) contribution to myocardial NO• responses occurred with increasing severity of diabetes. Nevertheless, activation of sGC by HNO remained intact in the myocardium. Innovation: Diabetes is associated with marked attenuation of vascular and myocardial effects of NO and NO donors, and this NO• resistance is circumvented by HNO, suggesting potential therapeutic utility for HNO donors in cardiovascular emergencies in diabetics. Conclusion: These results provide the first evidence that NO• resistance occurs in diabetic hearts, and that HNO largely circumvents this problem. Further, the positive inotropic and lusitropic effects of HNO are enhanced in a severely diabetic myocardium, a finding that warrants further mechanistic interrogation. The results support a potential role for therapeutic HNO administration in acute treatment of ischemia and/or heart failure in diabetics.Cheng Xue Qin, Jarryd Anthonisz, Chen Huei Leo, Nicola Kahlberg, Anida Velagic, Mandy Li, Edwina Jap, Owen L. Woodman, Laura J. Parry, John D. Horowitz, Barbara K. Kemp-Harper, and Rebecca H. Ritchi
The truth depends on the usefulness
No full textFake News, Manipulation und Propaganda verweisen in den Netzen der globalen Wissens- und Informationsgesellschaft auf grundlegende Mechanismen der sozialen Reproduktion. Denn das Internet markiert eine entscheidende Wahlmöglichkeit zwischen dem Wahren und dem Falschen. Desinformation und Manipulation erscheinen dabei als legitime Mittel der politischen Kommunikation, in der es mehr und mehr darum geht, die Nützlichkeit einer gegebenen Information zu bestimmen. Zwischen normativen Bildungsvorstellungen und informellen Handlungspraktiken eröffnet sich mithin auch ein Raum, in dem Wahrheit und Lüge auf dem Spiel stehen. Abschließend konkretisiert der Autor seine Thesen mit einem einfachen (und medienpädagogisch einfach umsetzbaren) Anwendungsbeispiel für den Schulunterricht.Fake news, manipulation and propaganda point to fundamental mechanisms of social reproduction in the networks of the global knowledge and information society. Because the Internet marks a crucial choice between the true and the false. Disinformation and manipulation appear as legitimate means of political communication, in which it is more and more important to determine the usefulness of a given information. Between normative educational conceptions and informal practices, a space opens where truth and lies are at stake. Finally, the author concretizes his theses with a simple (and media-educationally easy to apply) application example for school lessons
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