Experimental investigation on the sediment movement in the vicinity of a cylindrical bridge pier

River engineeringInnovative field and laboratory instrumentatio

Void-and-Cluster Sampling of Large Scattered Data and Trajectories

We propose a data reduction technique for scattered data based on statistical sampling. Our void-and-cluster sampling technique finds a representative subset that is optimally distributed in the spatial domain with respect to the blue noise property. In addition, it can adapt to a given density function, which we use to sample regions of high complexity in the multivariate value domain more densely. Moreover, our sampling technique implicitly defines an ordering on the samples that enables progressive data loading and a continuous level-of-detail representation. We extend our technique to sample time-dependent trajectories, for example pathlines in a time interval, using an efficient and iterative approach. Furthermore, we introduce a local and continuous error measure to quantify how well a set of samples represents the original dataset. We apply this error measure during sampling to guide the number of samples that are taken. Finally, we use this error measure and other quantities to evaluate the quality, performance, and scalability of our algorithm.Comment: To appear in IEEE Transactions on Visualization and Computer Graphics as a special issue from the proceedings of VIS 201

Reference System Element Identification Atlas – methods and tools to identify references system elements in product engineering

Companies target innovations, successful new products. One major challenge is to increase efficiency and decrease the risk of developing new successful products. We want to reach these goals by improving the reusability of already existing knowledge elements extracted from e.g., already existing (sub-)systems or their documentation. These elements are called reference system elements and are meant to be the starting point for product development projects. Based on a systematic literature review complemented by an expert workshop and analysis of established methods and tools in product engineering, we developed the Reference System Elements Identification Atlas to support the identification of suiting reference system elements. Within the Reference System Elements Identification Atlas, we collected 30 methods and tools to identify reference system elements and allocated them to the various knowledge spaces they search. All 30 methods and tools were grouped in five clusters – creativity methods, data analysis methods, market/competition analysis methods, similarity methods, and trend analysis methods. We observed that methods and tools are hardly related to the identification of reference system elements in literature explicitly. We believe the Reference System Elements Identification Atlas provides valuable support to collect valuable reference system elements as the starting point in product engineering

Risikofaktoren und Multifaktormodelle für den Deutschen Aktienmarkt (Risk Factors and Multi-Factor Models for the German Stock Market)

Der deutsche Aktienmarkt sah sich in den letzten 15 Jahren substantiellen Veränderungen gegenüber, welche unter anderem in eine zunehmende Internationalisierung und deutlich erhöhten Streubesitz mündeten. In der vorliegenden Arbeit untersuchen wir, inwieweit dies die aus klassischen Multifaktormodellen bekannten Risikofaktoren beeinflusste. Basierend auf den Renditen derCDAX-Unternehmen von Juli 1996 bis Juni 2011 dokumentieren wir vier wesentliche Ergebnisse. Erstens finden wir eine insignifikant (positive) Marktrisikoprämie, eine signifikant negative Größenprämie (Size Premium), eine signifikant positive Substanzprämie (Value Premium) und eine signifikant positive Momentumprämie (Momentum Premium). Zweitens zeigen sich alle vier Faktoren untereinander nur schwach bzw. negativ korreliert und teilweise mit internationalen Gegenstücken nur schwach korreliert. Drittens zeigt sich, dass Renditen von Aktienportfolios, sortiert nach Marktkapitalisierung und Buch-Marktwert-Verhältnis, durch ein Dreifaktorenmodell nach Fama French (1993) substantiell besser erklärt werden, als durch ein Einfaktormodell in Anlehnung an das klassische Capital Asset Pricing Model. Der zusätzliche Erklärungsbeitrag des Momentumfaktors in Anlehnung an Carhart (1997) ist hingegen marginal. Letztendlich argumentieren wir daher vor dem Hintergrund der bekannten Literatur und unserer Ergebnisse für eine länderspezifische Erweiterung des Capital Asset Pricing Models. -- For the last 15 years, the German stock market has been facing substantial changes that resulted in increasing internationalization and a higher free float. In this paper, we investigate to what extent these changes influenced the well-known risk factors of standard multi-factor models. Based on the returns of all stocks listed in the German composite index CDAX (all domestic companies of the Prime and General Standard of the Frankfurt Stock Exchange) from July 1996 to June 2011, we document four major results: First, we find an insignificant (positive) market risk premium, a significant negative size premium, a significant positive value premium and a significant positive momentum premium. Second, the correlation within all four risk factors is only weakly positive or even negative and with international counterparts only weak. Third, we find that returns of portfolios, sorted by market capitalization and book-to-market equity, are captured substantially better by multi-factor models by Fama/French (1993) or Carhart (1997) than by the one-factor model based on the standard Capital Asset Pricing Model. Finally, after comparing our findings for the last 15 years with the existing literature, we conclude for a country specific extension of the Capital Asset Pricing Model.CAPM,multi-factor models,asset pricing,asset pricing anomalies,anomalies,Fama French,Carhart,risk factors,value,size,momentum,Germany

Challenges in Reference System Management – Descriptive Model of Barriers using Research Results as Reference System Elements in Corporate Product Engineering

When engineering new products and systems, engineers take reference to already existing (socio-)technical systems or sub-systems to reduce development time and risk. These references can originate from e.g., previous products, competitors, nature, or research. Consolidated and linked to each other in a reference system, these references form the basis and starting point of the development as reference system elements. Especially research is a rich and potent source for reference system elements regarding knowledge and technologies on the edge in all disciplines. Using this source is a non-trivial process. Thus, it can often be neglected by many companies. The goal of this publication is the exploration of barriers and challenges arising when engineers want to use research results as reference system elements in corporate product engineering. Based on semi-structured interviews with experts from nine different companies, here we present a descriptive model that explains and sets barriers and challenges in context with different types of research results as well as the methods and approaches to gather them. E.g., the results show that often the lack of a description of the possible applications of research results is a barrier to perceiving their value. We anticipate our model to be a starting point for further research to improve the applicability of research results as reference system elements in corporate product engineering. Therefore, we intend to develop recommendations and guidelines for product engineers and researchers respectively to overcome the barriers and improve the representation of research results

Design of a Guideline for a Strategy Process of medium-sized Companies

Companies with a clear, documented strategy perform better than their competitors without a strategy. Nevertheless, the strategy process confronts medium-sized companies (250-3,000 employees) with major challenges while many of them do not have a clear strategy process. Reasons for that can be the focus on operations and thus lack of time and resources, missing methods knowledge, or the underestimation of the value of a strategy. In times of a structural change in an industry, as we see it currently for example with the electrification of the automotive industry, a strategy becomes even more important. The automotive supplier industry alone employs around 150,000 people just in medium-sized companies in Germany. This paper aims to design a guideline that supports medium-sized companies to define their long-term goals and in the implementation of their derived strategy. Based on a literature review and 16 expert interviews a guideline was developed that contains templates to document the strategy process and a process model including checklists to fill the templates. The guideline was initially evaluated against the defined success factors in a medium-sized company

Habitatpotentiale im Ackerbereich: Endergebnisse des LfULG-FuE-Projekts: Habitatpotentiale im Ackerbereich: Konzipierung und Erprobung schlagintegrierter Artenschutzmaßnahmen im LVG Köllitsch

Die Broschüre informiert über ein Projekt zur Umsetzung von einer angepassten Ackerrandbewirtschaftung zur Erhöhung des Habitatpotentials für Tiere und Pflanzen. Am Ackerrand wurden auf 9 m breiten Streifen die Effekte von Weiter Reihe und Untersaat von Luzerne untersucht. Es konnte nachgewiesen werden das mit den Maßnahmen mehr Laufkäfer und Spinnen den Acker besiedeln. Die Wirkung der Maßnahmenstreifen waren höher wenn sie an Landschaftselemente angrenzten. Die Publikation richtet sich an Landwirte, Berater und Naturschützer und soll zur Nachahmung der entsprechenden Maßnahmen einladen. Redaktionsschluss: 18.01.202