Low-cost embedded system for relative localization in robotic swarms

In this paper, we present a small, light-weight, low-cost, fast and reliable system designed to satisfy requirements of relative localization within a swarm of micro aerial vehicles. The core of the proposed solution is based on off-the-shelf components consisting of the Caspa camera module and Gumstix Overo board accompanied by a developed efficient image processing method for detecting black and white circular patterns. Although the idea of the roundel recognition is simple, the developed system exhibits reliable and fast estimation of the relative position of the pattern up to 30 fps using the full resolution of the Caspa camera. Thus, the system is suited to meet requirements for a vision based stabilization of the robotic swarm. The intent of this paper is to present the developed system as an enabling technology for various robotic tasks

Tuning the critical solution temperature of polymers by copolymerization

We study statistical copolymerization effects on the upper critical solution temperature (CST) of generic homopolymers by means of coarse-grained Langevin dynamics computer simulations and mean-field theory. Our systematic investigation reveals that the CST can change monotonically or non-monotonically with copolymerization, as observed in experimental studies, depending on the degree of non-additivity of the monomer (A-B) cross-interactions. The simulation findings are confirmed and qualitatively explained by a combination of a two-component Flory-de Gennes model for polymer collapse and a simple thermodynamic expansion approach. Our findings provide some rationale behind the effects of copolymerization and may be helpful for tuning CST behavior of polymers in soft material design.Comment: 8 pages, 6 figure

Consumer credit.

Resumé Tato diplomová práce se zabývá analýzou právních předpisů vztahujících se k úvěru pro spotřebitele. V této oblasti ochrany spotřebitele nastal v posledních letech vývoj zejména na poli evropského zákonodárství, který se nutností transpozice evropských směrnic promítl i do českého právního řádu. Diplomová práce popisuje vývoj právní úpravy spotřebitelských úvěrů na evropské úrovni počínaje směrnicí 87/102/EHS a dále směrnicí CCD a směrnicí MCD, která je posledním legislativním počinem unijního zákonodárce v této oblasti, v tuzemském právním řádu počínaje zákonem 321/2001, dále zákonem 145/2010 a nakonec současnou právní úpravou zákonem o spotřebitelském úvěru. Zákon o spotřebitelském úvěru obsahuje komplexní úpravu činností poskytování a zprostředkování spotřebitelského úvěru, regulace subjektů vystupujících na trhu spotřebitelských úvěrů, jakož i práv a povinností při poskytování a zprostředkování spotřebitelského úvěru. V první kapitole jsou vymezeny pojmy potřebné pro pochopení problematiky spotřebitelských úvěrů, jako je pojem spotřebitele, úvěru a spotřebitelského úvěru. První kapitola dále obsahuje základní popis problematiky ochrany spotřebitele, která jako oblast práva zastřešuje všechny oblasti právních vztahů, ve kterých spotřebitel vystupuje. Jednou z těchto oblastí je právě trh...This diploma thesis analyzes legislation governing consumer credit. In the recent past, a notable development has occurred in this particular area of consumer protection, especially in the field of European legislation. This development has also been reflected in the Czech legal system due to the necessity of transposing European directives. This diploma thesis describes the development of consumer credit legislation at European level starting with Directive 87/102/EHS and also by the Consumer Credit Directive and the Mortgage Credit Directive, which is the last legislative act of the Union legislator in this area and in the domestic legal system starting with Act 321/2001, following with Act 145/2010 and finishing with the current legislation by the Consumer Credit Act. The Consumer Credit Act contains a comprehensive regulation of the activities of providing and mediating consumer credit, regulation of entities operating on the consumer credit market as well as rights and obligations in the provision and mediation of consumer credit. The first chapter defines terms needed to understand consumer credit issues such as consumer, credit and consumer credit terms. The first chapter also contains a basic description of the issue of consumer protection, which, as a legal area, covers all areas of legal...Department of Business LawKatedra obchodního právaFaculty of LawPrávnická fakult

Entwurf und Herstellung von dünnwandigen Faltwerken aus zementbasierten Verbundwerkstoffen

Der in den Ingenieurwissenschaften zunehmend populäre Einsatz der Origami-Technik eröffnet neue Möglichkeiten zur Herstellung von effizienten Tragkonstruktionen [1]–[5]. In Verbindung mit leistungsfähigen, zementbasierten Verbundwerkstoffen bietet die Origami-Technik einen innovativen Ansatz für Entwurf und Realisierung von leichten tragenden Strukturen nach dem Prinzip form follows force – dem Grundgedanken des SPP 1542. [Aus: Motivation und Zielsetzung]The increasingly popular use of origami technology in the engineering sciences opens up new possibilities for the manufacture of efficient load-bearing structures [1]–[5]. In combination with high-performance, cement-based composite materials, origami technology of ers an innovative approach to the design and realisation of lightweight load-bearing structures based on the principle form follows force –the basic idea of SPP 1542. [Off: Motivation and objectives

A conceptual design tool to support high-speed vehicle design

This paper aims at presenting an integrated multidisciplinary methodology and the related software tool, called ASTRID-H, developed at Politecnico di Torino to support the conceptual and preliminary design phases of high-speed vehicles. Based on the experience in the development of innovative methodologies to cope with complex and highly integrated aircraft, ASTRID-H has been developed to guide students, researchers and engineers through the very first phases of the design of high-speed vehicles. ASTRID-H supports the users to move from the statistical evaluation of the guess data and the identification of the design space to the geometrical characterization of the vehicle guaranteeing a proper integration of the main subsystems. Already available and widely used mathematical models are here integrated in a new algorithm to face the complexity of the design of high-speed vehicles. In addition, the coefficients of the semi-empirical models that were not focusing on high-speed vehicles have been updated to widen classical theories to cover high-speed vehicles. The resulting implemented methodology allows the users to cope with complex multidisciplinary problems, which encompass a variety of interrelated disciplines and heterogeneous levels of fidelity. Furthermore, this paper reports the some of the main results achieved during the validation of the methodology thanks to the application to the STRATOFLY MR3 vehicle case study. STRATOFLY MR3 is a Mach 8 waverider configuration that stems from more than a decade of European research activities in the field of high-speed and currently under investigation in the Horizon 2020 STRATOFLY Project

Parameters of the NERA spectrometer for cold and thermal moderators of the IBR-2 pulsed reactor

The inverted geometry time-of-flight spectrometer NERA designed for simultaneous investigation of elastic and inelastic neutron scattering was constructed on a 100 meter long flight path of the IBR-2 reactor at JINR, Dubna, Russia. Spectrometer parameters were optimized for the thermal neutron spectrum of a water moderator at 330 K. Recently, a new type of cold neutron source operating at 30 K was installed in the sector of six horizontal channels. The cold source in combination with the water moderator allows one to effectively use incident neutrons in wide range of wavelengths

Hydroxyapatite Nanopowder Synthesis with a Programmed Resorption Rate

A microwave, solvothermal synthesis of hydroxyapatite (HAp) nanopowder with a programmed material resorption rate was developed. The aqueous reaction solution was heated by a microwave radiation field with high energy density. The measurements included powder X-ray diffraction (PXRD) and the density, specific surface area (SSA), and chemical composition as specified by the inductively coupled plasma optical emission spectrometry technique (ICP-OES). The morphology and structure were investigated using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). A degradation test in accordance with norm ISO 10993-4 was conducted. The developed method enables control of the average grain size and chemical composition of the obtained HAp nanoparticles by regulating the microwave radiation time. As a consequence, it allows programming of the material degradation rate and makes possible an adjustment of the material activity in a human body to meet individual resorption rate needs. The authors synthesized a pure, fully crystalline hexagonal hydroxyapatite nanopowder with a specific surface area from 60 to almost 240 m2/g, a Ca/P molar ratio in the range of 1.57–1.67, and an average grain size from 6 nm to over 30 nm. A 28-day degradation test indicated that the material solubility ranged from 4 to 20 mg/dm3

Photocatalytic Oxidative [2+2] Cycloelimination Reactions with Flavinium Salts: Mechanistic Study and Influence of the Catalyst Structure

Flavinium salts are frequently used in organo‐catalysis but their application in photoredox catalysis has not been systematically investigated, yet. Here, we synthesize a series of 5‐ethyl‐3‐methylalloxazinium salts with different substituents in positions 7 and 8 and investigate their application in light‐dependent oxidative cycloelimination of cyclobutanes. Detailed mechanistic investigations with a coumarin dimer as a model substrate reveal that the reaction preferentially occurs via the triplet‐born radical pair after electron transfer from the substrate to the triplet state of an alloxazinium salt. The very photostable 7,8‐dimethoxyderivative turns out to be a superior catalyst with a sufficiently high oxidation power (E* = 2.26 V) allowing the conversion of various cyclobutanes (with Eox up to 2.05 V) in high yields. Even compounds can be converted whose opening requires overcoming a high activation barrier due to a missing pre‐activation caused by bulky adjacent substituents, that favour ring opening, e.g. all‐trans dimethyl 3,4‐bis(4‐methoxyphenyl)cyclobutane‐1,2‐dicarboxylate

Non-local energetics of random heterogeneous lattices

In this paper, we study the mechanics of statistically non-uniform two-phase elastic discrete structures. In particular, following the methodology proposed in (Luciano and Willis, Journal of the Mechanics and Physics of Solids 53, 1505-1522, 2005), energetic bounds and estimates of the Hashin-Shtrikman-Willis type are developed for discrete systems with a heterogeneity distribution quantified by second-order spatial statistics. As illustrated by three numerical case studies, the resulting expressions for the ensemble average of the potential energy are fully explicit, computationally feasible and free of adjustable parameters. Moreover, the comparison with reference Monte-Carlo simulations confirms a notable improvement in accuracy with respect to approaches based solely on the first-order statistics.Comment: 32 pages, 8 figure

System for deployment of groups of unmanned micro aerial vehicles in GPS-denied environments using onboard visual relative localization

A complex system for control of swarms of micro aerial vehicles (MAV), in literature also called as unmanned aerial vehicles (UAV) or unmanned aerial systems (UAS), stabilized via an onboard visual relative localization is described in this paper. The main purpose of this work is to verify the possibility of self-stabilization of multi-MAV groups without an external global positioning system. This approach enables the deployment of MAV swarms outside laboratory conditions, and it may be considered an enabling technique for utilizing fleets of MAVs in real-world scenarios. The proposed visual-based stabilization approach has been designed for numerous different multi-UAV robotic applications (leader-follower UAV formation stabilization, UAV swarm stabilization and deployment in surveillance scenarios, cooperative UAV sensory measurement) in this paper. Deployment of the system in real-world scenarios truthfully verifies its operational constraints, given by limited onboard sensing suites and processing capabilities. The performance of the presented approach (MAV control, motion planning, MAV stabilization, and trajectory planning) in multi-MAV applications has been validated by experimental results in indoor as well as in challenging outdoor environments (e.g., in windy conditions and in a former pit mine)