Weighting (Version 2.0)

This contribution deals with the fundamental principles of weighting; the various types of weighting are taken into account. Terms such as design weighting and adjustment weighting are explained, and the Horvitz-Thompson estimator and the GREG estimator are presented

A New Resistive Adaptive Gate-Driving Concept with Automated Identification of Operational Parameters

This paper proposes a new adaptive gate-driving concept based on parallel-connected resistive driving stages, which allows the modification of the effective gate-resistance for every turn-on and turn-off event during operation. By selecting the appropriate gate-resistance, the switching behavior can be optimized individually for each specific operating point (Vsw, Isw, Tj). As a result, higher efficiency under partial load can be achieved. The selection of effective gate-resistance is based on the results of a here introduced automatic optimization method, which takes constraints such as dv/dt- and di/dt-limits into account. Subject of this paper is also the comparison of the new approach with the widely used single-stage resistive driver

Synthetic data for open and reproducible methodological research in social sciences and official statistics

In der Forschung nehmen Vergleichbarkeit und Reproduzierbarkeit immer mehr an Bedeutung zu. Die empirische Forschung profitiert dabei von Forschungsdatenzentren und Scientific Use Files. Für angewandte Methodenforschung dagegen sind geeignete Datenquellen kaum verfügbar, obwohl gerade in den Wirtschafts- und Sozialwissenschaften komplexe Stichprobendesigns bei der Entwicklung und Anwendung von Schätzmethoden berücksichtigt werden müssen. In dieser Arbeit wird ein synthetischer, jedoch realistischer Datensatz vorgestellt, der gerade die Evaluierung und Entwicklung von Schätzmethoden in den Sozial- und Wirtschaftswissenschaften unterstützt. Der Schwerpunkt liegt dabei auf vergleichbarer und reproduzierbarer Forschung in einer realistischen Umgebung in Bezug auf Individual- und Haushaltsdaten. Dieser Datensatz wird der Forschungsgemeinde frei zur Verfügung gestellt.Open and reproducible research receives more and more attention in the research community. Whereas empirical research may benefit from research data centres or scientific use files that foster using data in a safe environment or with remote access, methodological research suffers from the availability of adequate data sources. In economic and social sciences, an additional drawback results from the presence of complex survey designs in the data generating process, that has to be considered when developing and applying estimators. In the present paper, we present a synthetic but realistic dataset based on social science data, that fosters evaluating and developing estimators in social sciences. The focus is on supporting comparable and reproducible research in a realistic framework providing individual and household data. The outcome is provided as an open research data resource

A simulation approach to estimate inclusion probabilities for PIAAC Germany

"In PIAAC (Programme for the International Assessment of Adult Competencies) inclusion probabilities have to be known for every respondent at each sampling stage in all participating countries. However, in some cases it is not possible to calculate inclusion probabilities for a sample survey analytically - although the underlying design is probabilistic. In such cases, simulation studies can help to estimate inclusion probabilities and thus ensure that the necessary basis for the calculation of design weights is available. In this section, we present a Monte Carlo simulation using the German sample data. During the selection process for PIAAC Germany an error had occurred. Because of that, it was not possible to determine the inclusion probabilities analytically. Therefore a simulation study with 10,000 runs of the erroneous selection process was set up. As a result it was possible to compute the inclusion probabilities for the sample of PIAAC Germany." (author's abstract

Gewichtung (Version 1.1)

In diesem Kapitel werden die Grundlagen der Gewichtung behandelt. Dabei werden die verschiedenen Arten der Gewichtung berücksichtigt. Termini wie Designgewichtung und Anpassungsgewichtung werden erläutert. Neben dem Horvitz-Thompson Schätzer wird auch der GREG-Schätzer vorgestellt

The quiescent light curve and evolutionary state of GRO J1655-40

We present ellipsoidal light-curve fits to the quiescent B, V, R and I light curves of GRO J1655-40 (Nova Scorpii 1994). The fits are based on a simple model consisting of a Roche-lobe filling secondary and an accretion disc around the black-hole primary. Unlike previous studies, no assumptions are made about the interstellar extinction or the distance to the source; instead these are determined self-consistently from the observed light curves. In order to obtain tighter limits on the model parameters, we used the distance determination from the kinematics of the radio jet as an additional constraint. We obtain a value for the extinction that is lower than was assumed previously; this leads to lower masses for both the black hole and the secondary star of 5.4 +/- 0.3 Msun and 1.45 +/- 0.35 Msun, respectively. The errors in the determination of the model parameters are dominated by systematic errors, in particular due to uncertainties in the modeling of the disk structure and uncertainties in the atmosphere model for the chemically anomalous secondary in the system. A lower mass of the secondary naturally explains the transient nature of the system if it is either in a late case A or early case B mass-transfer phase.Comment: 12 pages, 4 figures, submitted to MNRA

Vergleich verschiedener Ansätze zur nachhaltigen Olefinproduktion nach dem MtO‐ und FT‐Verfahren

Olefine sind ein essenzieller Bestandteil der modernen organischen Chemie. Nach aktuellem Stand der Technik wird meist Roho¨l als Rohstoff verwendet, welches zuna¨chst in einer Raffinerie fraktioniert wird. Anschließend wird die Naphthafraktion einem Steamcracker zugefu¨hrt, in dem die Kohlenwasserstoffe zu den gewu¨nschten Olefinen gecrackt werden. Zur Grundlage der Diskussion, welche alternative Wege sich zur Erzeugung von Olefinen anbieten, werden in diesem Beitrag zwei ausgewa¨hlte alternative Herstellungsprozessrouten miteinander verglichen