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The aim of the paper is to present the simulation of the sweeping process based on a mathematical model that includes the drag force, the lift force, the sideway force, and the gravity. At the beginning, it is presented a short history of the street sweepers, some considerations about the sweeping process and the parameters of the sweeping process. Considering the developed model, in Matlab there is done some simulation for the trajectory of a spherical pebble. The obtained results are presented in graphical shape.

Several possibilities of tests under load on a chassis dynamometer are presented. Consumption measurements according standard driving cycles as the New European Drive Cycle (NEDC) and Worldwide harmonized light duty test procedure/cycle (WLTP/WLTC) make special attention to the observance of the regulations necessary. The rotational masses of inertia and the load depending on velocity have to match the required values. Load tests as well allow the determination of the maximum acceleration in the current gear and the slippage of the driven wheels.

The method of signal injection is investigated for position estimation of proportional solenoid valves. A simple observer is proposed to estimate a position-dependent parameter, i.e. the eddy current resistance, from which the position is calculated analytically. Therefore, the relationship of position and impedance in the case of sinusoidal excitation is accurately described by consideration of classical electrodynamics. The observer approach is compared with a standard identification method, and evaluated by practical experiments on an off-the-shelf proportional solenoid valve.

Sliding-mode observation with iterative parameter adaption for fast-switching solenoid valves
(2016)

Control of the armature motion of fast-switching solenoid valves is highly desired to reduce noise emission and wear of material. For feedback control, information of the current position and velocity of the armature are necessary. In mass production applications, however, position sensors are unavailable due to cost and fabrication reasons. Thus, position estimation by measuring merely electrical quantities is a key enabler for advanced control, and, hence, for efficient and robust operation of digital valves in advanced hydraulic applications. The work presented here addresses the problem of state estimation, i.e., position and velocity of the armature, by sole use of electrical measurements. The considered devices typically exhibit nonlinear and very fast dynamics, which makes observer design a challenging task. In view of the presence of parameter uncertainty and possible modeling inaccuracy, the robustness properties of sliding mode observation techniques are deployed here. The focus is on error convergence in the presence of several sources for modeling uncertainty and inaccuracy. Furthermore, the cyclic operation of switching solenoids is exploited to iteratively correct a critical parameter by taking into account the norm of the observation error of past switching cycles of the process. A thorough discussion on real-world experimental results highlights the usefulness of the proposed state observation approach.

In this paper, a gain-scheduled nonlinear control structure is proposed for a surface vessel, which takes advantage of extended linearisation techniques. Thereby, an accurate tracking of desired trajectories can be guaranteed that contributes to a safe and reliable water transport. The PI state feedback control is extended by a feedforward control based on an inverse system model. To achieve an accurate trajectory tracking, however, an observer-based disturbance compensation is necessary: external disturbances by cross currents or wind forces in lateral direction and wave-induced measurement disturbances are estimated by a nonlinear observer and used for a compensation. The efficiency and the achieved tracking performance are shown by simulation results using a validated model of the ship Korona at the HTWG Konstanz, Germany. Here, both tracking behaviour and rejection of disturbance forces in lateral direction are considered.

This work investigates data compression algorithms for applications in non-volatile flash memories. The main goal of the data compression is to minimize the amount of user data such that the redundancy of the error correction coding can be increased and the reliability of the error correction can be improved. A compression algorithm is proposed that combines a modified move-to-front algorithm with Huffman coding. The proposed data compression algorithm has low complexity, but provides a compression gain comparable to the Lempel-Ziv-Welch algorithm.

In this paper totally nonnegative (positive) matrices are considered which are matrices having all their minors nonnegative (positve); the almost totally positive matrices form a class between the totally nonnegative matrices and the totally positive ones. An efficient determinantal test based on the Cauchon algorithm for checking a given matrix for falling in one of these three classes of matrices is applied to matrices which are related to roots of polynomials and poles of rational functions, specifically the Hankel matrix associated with the Laurent series at infinity of a rational function and matrices of Hurwitz type associated with polynomials. In both cases it is concluded from properties of one or two finite sections of the infinite matrix that the infinite matrix itself has these or related properties. Then the results are applied to derive a sufficient condition for the Hurwitz stability of an interval family of polynomials. Finally, interval problems for a subclass of the rational functions, viz. R-functions, are investigated. These problems include invariance of exclusively positive poles and exclusively negative roots in the presence of variation of the coefficients of the polynomials within given intervals.

A real matrix is called totally nonnegative if all of its minors are nonnegative. In this paper the extended Perron complement of a principal submatrix in a matrix A is investigated. In extension of known results it is shown that if A is irreducible and totally nonnegative and the principal submatrix consists of some specified consecutive rows then the extended Perron complement is totally nonnegative. Also inequalities between minors of the extended Perron complement and the Schur complement are presented.

We consider classes of n-by-n sign regular matrices, i.e., of matrices with the property that all their minors of fixed order k have one specified sign or are allowed also to vanish, k = 1, ... ,n. If the sign is nonpositive for all k, such a matrix is called totally nonpositive. The application of the Cauchon algorithm to nonsingular totally nonpositive matrices is investigated and a new determinantal test for these matrices is derived. Also matrix intervals with respect to the checkerboard partial ordering are considered. This order is obtained from the usual entry-wise ordering on the set of the n-by-n matrices by reversing the inequality sign for each entry in a checkerboard fashion. For some classes of sign regular matrices it is shown that if the two bound matrices of such a matrix interval are both in the same class then all matrices lying between these two bound matrices are in the same class, too.

Der deutsche Jesuit Johannes Schreck, latinisiert Terrentius SJ (1576–1630), gehört zu den herausragenden, aber wenig bekannten frühen Chinamissionaren. Er war ein Freund Galileo Galileis, Mitglied der Accademia dei Lincei in Rom, ein bedeutender Arzt und Botaniker, Astronom und Mathematiker. 1611 trat er in den Jesuitenorden ein. Von 1619 bis zu seinem Tod 1630 wirkte er als Wissenschaftler und Missionar in China. Seine Leistungen auf den Gebieten der Medizin, Botanik, Astronomie, Technik und Philologie sind von großer Vielfalt und Breite. Erstmals liegt hier ein wissenschaftlich fundiertes Werk vor, das auch Sammlungen und Übersetzungen der Quellen, der Nachrufe und der zahlreichen Briefe von, an und über Schreck in deutscher Sprache enthält. Aus verschiedenen Blickwinkeln betrachten namhafte Wissenschaftler in diesem Band das Leben und Wirken dieser interessanten und vielschichtigen Persönlichkeit der Frühen Neuzeit.

Cloud Computing
(2016)

Scoring LSP tasks
(2016)

Energiewirtschaft und Wassernutzung stehen aufgrund der großen Bedeutung von Kohle-, Kern-, und Wasserkraftwerken in Baden-Württemberg in einem engen Zusammenhang. Niedrige Flusswasserstände können in Trockenzeiten zu Konflikten zwischen den verschiedenen Wassernutzern z.B. der Kühlwassernutzung (Abbildung 1), Bewässerung sowie der Nutzung des Neckars als Schifffahrtsstraße führen. Seit dem Trockensommer 2003 nimmt das Bewusstsein für die Relevanz konkurrierender Wassernutzungen, u.a. von Kühlwassernutzung, Bewässerung für die Landwirtschaft, Nutzung der Wasserwege für den Transport von Massengütern sowie für Belange des Naturschutz zu.

Stress is becoming an important topic in modern life. The influence of stress results in a higher rate of health disorders such as burnout, heart problems, obesity, asthma, diabetes, depressions and many others. Furthermore individual’s behavior and capabilities could be directly affected leading to altered cognition, inappropriate decision making and problem solving skills. In a dynamic and unpredictable environment, such as automotive, this can result in a higher risk for accidents. Different papers faced the estimation as well as prediction of drivers’ stress level during driving. Another important question is not only the stress level of the driver himself, but also the influence on and of a group of other drivers in the near area. This paper proposes a system, which determines a group of drivers in a near area as clusters and it derives the individual stress level. This information will be analyzed to generate a stress map, which represents a graphical view about road section with a higher stress influence. Aggregated data can be used to generate navigation routes with a lower stress influence to decrease stress influenced driving as well as improve road safety.

Sleep is an important aspect in life of every human being. The average sleep duration for an adult is approximately 7 h per day. Sleep is necessary to regenerate physical and psychological state of a human. A bad sleep quality has a major impact on the health status and can lead to different diseases. In this paper an approach will be presented, which uses a long-term monitoring of vital data gathered by a body sensor during the day and the night supported by mobile application connected to an analyzing system, to estimate sleep quality of its user as well as give recommendations to improve it in real-time. Actimetry and historical data will be used to improve the individual recommendations, based on common techniques used in the area of machine learning and big data analysis.

Traggerüste
(2016)

Schicksal der Freybrücke
(2016)

Karl Bernhard gilt als einer der bedeutendsten Bauingenieure in Deutschland Anfang des 20. Jahrhunderts. Seine beiden Brücken entlang der Heerstraße in Berlin, die Stößenseebrücke und die Freybrücke über die Havel, sind seit 1909 verkehrstechnisch von höchster Bedeutung für die Ost-West-Verbindung der Stadt. Die Freybrücke wurde jedoch im März 2015 abgerissen, um einem Ersatzneubau Platz zu machen. Wie kam es dazu, dass eine historisch und verkehrstechnisch derart wichtige, seit 1971 unter Denkmalschutz stehende Konstruktion so lange vernachlässigt wurde, bis sie abbruchreif war? Dieser Artikel ist eine Hommage an Bernhards Havelbrücke und geht ihrer wechselvollen Geschichte nach.

Ulrich Finsterwalder
(2016)

Karl Bernhard
(2016)

The development of native user interface components is a time consuming and repetitive process, especially for quite simple components like text fields in a form. In order to save time during development an approach is presented in this paper, abstracting the description of the elements into separate files independent from the source code. With aspects from generative and model-driven approaches this leads to simple reusable UI components without the need of deep knowledge in native programming languages.

TU Darmstadt HUMVIB-Bridge
(2016)

In this paper we propose a method to determine the active speaker for each time-frequency point in the noisy
signals of a microphone array. This detection is based
on a statistical model where the speech signals as well
as noise signals are assumed to be multivariate Gaussian
random variables in the Fourier domain. Based on this
model we derive a maximum-likelihood detector for the
active speaker. The decision is based on the a posteri-
ori signal to noise ratio (SNR) of a speaker dependent
max-SNR beamformer.

This letter introduces signal constellations based on multiplicative groups of Eisenstein integers, i.e., hexagonal lattices. These sets of Eisenstein integers are proposed as signal constellations for generalized spatial modulation. The algebraic properties of the new constellations are investigated and a set partitioning technique is developed. This technique can be used to design coded modulation schemes over hexagonal lattices.

A method is investigated by which tight bounds on the range of a multivariate rational function over a box can be computed. The approach relies on the expansion of the numerator and denominator polynomials in Bernstein polynomials. Convergence of the bounds to the range with respect to degree elevation of the Bernstein expansion, to the width of the box and to subdivision are proven and the inclusion isotonicity of the related enclosure function is shown.

Three-level inverters are used in electrical drive systems, as grid infeed inverter in PV power plants or as active power line filters. Up to now so called hard switching topologies have been used. A new 'Soft Switching Three Level Inverter (S3L Inverter)' which is now available provides reduced switching losses and higher efficiency. In this paper the S3L inverter is compared with a hard switching T-type inverter topology (H3L inverter). S3L inverters provide higher efficiency and additionally advantages in electromagnetic compatibility due to the soft switching performance, especially when using the 'Super Soft Switching Three Level Inverter (SS3L Inverter)'.

Domain-Specific modelling is increasingly adopted in the software development industry. While textual domain specific languages (DSLs) already have a wide impact, graphical DSLs still need to live up to their full potential. In this paper we describe an approach that reduces the time to create a graphical DSL to hours instead of months. The paper describes a generative approach to the creation of graphical editors for the Eclipse platform. A set of carefully designed textual DSLs together with an EMF meta-model are the input for the generator. The output is an Eclipse plugin for a graphical editor for the intended graphical language. The entire project is made available as open source under the name Spray and is being developed by an active community. This paper focuses on the description of the workflow and provides an introduction into the possibilities through this approach of a graphical modelling environment.

Domain-specific modeling is increasingly adopted in the software development industry. While textual domain-specific languages (DSLs) already have a wide impact, graphical DSLs still need to live up to their full potential. In this paper, we describe an approach to automatically generate a graphical DSL from a set of textual languages. With our approach, node and edge type graphical DSLs can be described using textual models. A set of carefully designed textual DSLs is the input for our generators. The result of the generation is a graphical editor for the intended domain. The development time for a graphical editor is reduced significantly. The whole project is available as open source under the name "Zeta". This publication focuses on the explanation of the textual DSLs for defining a graphical node and edge editor.

Domain-specific modeling is more and more understood as a comparable solution compared to classical software development. Textual domain-specific languages (DSLs) already have a massive impact in contrast tographical DSLs, they still have to show their full potential. The established textual DSLs are normally generated from a domain specific grammar or maybe other specific textual descriptions. And advantage of textual DSLs is that they can be development cost-efficient.
In this paper, we describe asimilar approach for the creation of graphical DSLs from textual descriptions. We present a set of specially developed textual DSLs to fully describe graphical DSLs based on node and edge diagrams. These are, together with an EMF meta-model, the input for a generator that produces an eclipse-based graphical Editor. The entire project is available as open source under the name MoDiGen.

Domain-specific modeling is increasingly adopted by the software development industry. While textual domain-specific languages (DSLs) already have a wide impact, graphical DSLs still need to live up to their full potential. Textual DSLs are usually generated from a grammar or other short textual notations; their development is often cost-efficient. In this paper, we describe an approach to similarly create graphical DSLs from textual notations. The paper describes an approach to generate a graphical node and edge online editor, using a set of carefully designed textual DSLs to fully describe graphical DSLs. Combined with an adequate metamodel, these textual definitions represent the input for a generator that produces a graphical Editor for the web with features such as collaboration, online storage and being always available. The entire project is made available as open source under the name Zeta. This paper focuses on the overall approach and the description of the textual DSLs that can be used to develop graphical modeling languages and editors.

For European space missions the importance of electric propulsion is strongly growing and has recently experienced a real burst in the telecom market. The initial drivers of this development were programs of the European Space Agency and projects of the European national space agencies. In addition, electric propulsion is now on the priority list of European commercial satellite manufacturers. Actual programs target orbit raising and station keeping with full electric propulsion for telecom satellites. European space industry, represented by individual companies, has developed specific and generic solutions for the electronics dedicated to powering and controlling electric propulsion systems. The European Space Agency and the European Commission providing support for enabling technology related to Power Processing Units (PPUs) and increasing competitiveness.

This paper studies suitable models for the identification of nonlinear acoustic systems. A cascaded structure of nonlinear filters is proposed that contains several parallel branches, consisting of polynomial functions followed by a linear filter for each order of nonlinearity. The second order of nonlinearity is additionally modelled with a parallel branch, containing a Volterra filter. These are followed by a long linear FIR filter that is able to model the room acoustics. The model is applied to the identification of a tube power amplifier feeding a guitar loudspeaker cabinet in an acoustic room. The adaptive identification is performed by the normalized least mean square (NLMS) algorithm. Compared with a generalized polynomial Hammerstein (GPH) model, the accuracy in modelling the dedicated real world system can be improved to a greater extend than increasing the order of nonlinearity in the GPH model.

The multichannel Wiener filter (MWF) is a well-established noise reduction technique for speech processing. Most commonly, the speech component in a selected reference microphone is estimated. The choice of this reference microphone influences the broadband output signal-to-noise ratio (SNR) as well as the speech distortion. Recently, a generalized formulation for the MWF (G-MWF) was proposed that uses a weighted sum of the individual transfer functions from the speaker to the microphones to form a better speech reference resulting in an improved broadband output SNR. For the MWF, the influence of the phase reference is often neglected, because it has no impact on the narrow-band output SNR. The G-MWF allows an arbitrary choice of the phase reference especially in the context of spatially distributed microphones.
In this work, we demonstrate that the phase reference determines the overall transfer function and hence has an impact on both the speech distortion and the broadband output SNR. We propose two speech references that achieve a better signal-to-reverberation ratio (SRR) and an improvement in the broadband output SNR. Both proposed references are based on the phase of a delay-and-sum beamformer. Hence, the time-difference-of-arrival (TDOA) of the speech source is required to align the signals. The different techniques are compared in terms of SRR and SNR performance.