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The effects of steps on the transition of laminar boundary layers were measured on a flat plate for low Reynolds numbers with critical and subcritical step heights. The transition position was measured by determining the intermittency distribution in streamwise direction, including the characteristic length of the transitional region. The results are compared with formulations of a critical step Reynolds number $${\textrm{Re}_\textrm{h}}$$ Re h , i.e., the step height that will instantly trigger transition at the step position, and—for subcritical step heights—with $${{\Delta N}}$$ Δ N -formulations from the literature. For backward-facing steps, the concept of a step Reynolds number can be used to distinguish between subcritical and critical step heights, whereas for forward-facing steps there seems not to be one unique $${\textrm{Re}_\textrm{h}}$$ Re h . Furthermore, for subcritical backward-facing steps the concept of a $${{\Delta N}}$$ Δ N -approximation gives a reasonable description of the experimental observations. Again in contrast, for forward-facing steps a $${{\Delta N}}$$ Δ N -approach scattered a lot and no clear dependency was found between the reduction in the critical N-factor of transition and the relative step height.

"IndExs—Index of Exsiccatae" is an online database with bibliographic information on exsiccatae and exsiccata-like series launched in 2001 (Triebel and Scholz 2022). This type of series is a specific system in botany and mycology to create, publish and distribute well identified and documented reference material. In most cases the distributed specimens are numbered and each number consists of uniform material (herbarium duplicates) from a single collection event. Exsiccatal series are regularily published with small booklets containing the printed labels/ schedae of each numbered entity. The title of the series often shows the geographic and taxonomic focus of the series, e.g., "Delogne & Gravet, Hépat. Ardenne" and "Hertel, Lecideaceae Exs.". The persons editing the series are specialists, often recognized botanists and taxonomists. They are mostly not identical with the persons collecting and identifying the specimens distributed. Examples are E. M. Fries with "Fries, Herb. Norm. Pl. Suec.", G. L. Rabenhorst who published 24 series with more than 6,000 numbered entities and K. H. Rechinger with "Rechinger & Polunin, Exs. Herb. Baghdad". In the minority of cases the editors are anonymous persons and organisations devoted to plant exchange like "Société Dauphinoise pour l'échange des plantes". The more than 2.200 known series are widely distributed in public herbaria, either kept separately or integrated in the main collection. We estimate that more than 10 million specimens belong to such a series with printed labels. Approximately 70 series are running. The eldest exsiccata might be that of Johann Balthasar Ehrhart (from 1732 see here). It is followed by the better known exsiccatae edited by Jakob Friedrich Ehrhart, e.g., the series "Ehrhart, Pl. Crypt. Linn." starting with 1785. The two newest series started in 2020 and are bryophyte series from Taiwan and Vietnam. The online database IndExs categorizes the series according to the group of organisms distributed and delivers editors, full title, standard abbreviation, editing institution, place of publication, range of (suggested) publication dates, range of numbered entities, examplary images of printed label as well as information sources and literature (Triebel et al. 2004). A stable and persistent exsiccata identifier, so-called "IndExs Exsiccata ID" is given. This set of standardized information is available via the IndExs search interface, and ready to be downloaded via several formats (csv, xls, xml). A machine readable REST web service is under development. IndExs information and services with stable IndExs Exsiccata ID are used by data portals like the Macroalgal Herbarium Consortium Portal powered by Symbiota, the JACQ herbarium management system and integrated in collection management systems like DiversityCollection, a module of the Diversity Workbench (DWB) tool suite. It is envisaged to be included in future terminology services like the GFBio Terminology Service. IndExs is appropriate to build the curated reference list for exsiccatae in the frame of herbarium digitization approaches (Borsch et al. 2020). IndExs is storing information on the work of 1,300 editors of exsiccatae who are persons from nearly 300 years. According to the data models of DiversityAgents (Weiss et al. 2016) and DiversityExsiccatae (Hagedorn et al. 2008) the information is managed in freely accessible interlinked instances of SQL RDBMS DiversityAgents and DiversityExsiccatae. The applications are installed as part of the data network at the SNSB IT Center. In 2012, the Wikidata project started and acts as central storage for the structured data of its Wikimedia sister projects (Anonymous 2022, Vrandečić and Krötzsch 2014). The content of Wikidata is available under a free license, exported using standard formats, and can be interlinked to other open data sets on the linked data web including life sciences (Anonymous 2022, Mitraka et al. 2015). The study will use existing IndExs services for the 1,300 IndExs editors and 2,200 disambiguated exsiccata series and expand them for linked data / semantic web approaches. It will explore the usability of Wikidata: for disambiguation of person names (=editors) in IndExs by adapting Wikidata Identifiers, for adding information to existing Wikidata person Q-entities (items) via statements on persons´ work, for integrating IndExs information in Wikidata with URI for "IndExs Exsiccata ID" via a newly proposed P-entity (property) for this special kind of creative work in natural science, for adding new Q-entities in Wikidata for IndExs editors. for disambiguation of person names (=editors) in IndExs by adapting Wikidata Identifiers, for adding information to existing Wikidata person Q-entities (items) via statements on persons´ work, for integrating IndExs information in Wikidata with URI for "IndExs Exsiccata ID" via a newly proposed P-entity (property) for this special kind of creative work in natural science, for adding new Q-entities in Wikidata for IndExs editors. These editors of published booklet series with distributed physical material fulfill the Wikidata criteria of notability. They are often more or less well-known botanists and mycologists. By their published work they might even more fulfill the criteria than certain persons categorized as botanical collectors with assignment of a Wikidata ID through activities of CETAF, DiSSCo and COST MOBILISE.

Objectives: The Prospective Randomized On-X Mechanical Prosthesis Versus St Jude Medical Mechanical Prosthesis Evaluation (PROSE) trial purpose was to investigate whether a current-generation mechanical prosthesis (On-X; On-X Life Technologies/Artivion Inc) reduced the incidence of thromboembolic-related complications compared with a previous-generation mechanical prosthesis (St Jude Medical Mechanical Prosthesis; Abbott/St Jude Medical). This second report documents the valve-related complications by individual prostheses and by Western and Developing populations. Methods: The PROSE trial study was conducted in 28 worldwide centers and incorporated 855 subjects randomized between 2003 and 2016. The study enrollment was discontinued on August 31, 2016. The study protocol, and analyses of 10 demographic variables and 24 risk factors were published in detail in 2021. Results: The total patient population (N = 855) included patients receiving an On-X valve (n = 462) and a St Jude Medical valve (n = 393). The overall freedom evaluation showed no differences at 5 years between the prostheses for thromboembolism or for valve thrombosis. There were also no differences in mortality. There were several differences between Developing and Western populations. The freedom relations at 5 years for mortality favored Western over Developing populations. Valve thrombosis was differentiated by position and site: aortic < mitral (P = .007) and Western < Developing (P = .005). In the mitral position there were no cases in Western populations, whereas there were 8 in Developing populations (P = .217). Conclusions: The On-X valve and St Jude Medical valve performed equally well in the study with no differences found. The only differentiation occurred with valve thrombosis in the mitral position more than the aortic position and occurring in Developing more than Western populations. The occurrence of valve thrombosis was also related to a younger population possibly due to anticoagulation compliance based on record review.

Magnesium has a significantly lower density than steel or even aluminium and is therefore predestined as a lightweight construction material. Conventional magnesium alloys, however, are difficult or impossible to form at room temperature and corrode relatively easy. This paper will give an overview about the development of a material system, which consists of a novel formable magnesium alloy that is provided with an effective corrosion protection coating. The corrosion protection is to be realized in the form of a novel, forming stable powder coating, which can be applied in the coil coating process directly after sheet production. In order to improve the tribological properties during forming, additional additives are to be added to the powder coating formulation to positively influence the coefficient of friction. Ideally, additional lubricants can be completely dispensed with while maintaining high flexibility and adhesive strength of the coating layer. Within this paper, first results concerning tribological and forming behaviour of the new lightweight material system will be given as the example of strip drawing and cupping tests at room temperature under lubricated and dry conditions. For the benchmark, the results are compared with those obtained using a commercially available AZ31 Mg alloy to show the potential of this novel lightweight structural system.

Die Digitalisierung unserer Gesellschaft bedeutet für den Einzelhandel und unsere Städte einen tiefgreifenden Umbruch. Viele Menschen nutzen das Internet inzwischen regelmäßig für ihren Einkauf. Weiterhin hohe Wachstumsraten sprechen für eine anhaltende Dynamik bei der Verbreitung auch in Deutschland. Die veränderten Einkaufsgewohnheiten gehen mit einer Umsatzverlagerung vom stationären Handel in den Onlinehandel einher und verändern die Nutzungsstrukturen in den Stadtzentren. Dies wirft bezüglich der Raumentwicklung vielfältige Fragen auf. Die AG "Onlinehandel und Raumentwicklung" - ein ehrenamtlich arbeitendes, zeitlich befristetes, inter- und transdisziplinäres Gremium der Landesarbeitsgemeinschaft Nordrhein-Westfalen der Akademie für Raumentwicklung in der Leibniz-Gemeinschaft (ARL) - hat diese Fragen aufgegriffen und diskutiert.

Die Digitalisierung unserer Gesellschaft bedeutet für den Einzelhandel und unsere Städte einen tiefgreifenden Umbruch. Viele Menschen nutzen das Internet inzwischen regelmäßig für ihren Einkauf. Weiterhin hohe Wachstumsraten sprechen für eine anhaltende Dynamik bei der Verbreitung auch in Deutschland. Die veränderten Einkaufsgewohnheiten gehen mit einer Umsatzverlagerung vom stationären Handel in den Onlinehandel einher und verändern die Nutzungsstrukturen in den Stadtzentren. Dies wirft bezüglich der Raumentwicklung vielfältige Fragen auf. Die AG "Onlinehandel und Raumentwicklung" - ein ehrenamtlich arbeitendes, zeitlich befristetes, inter- und transdisziplinäres Gremium der Landesarbeitsgemeinschaft Nordrhein-Westfalen der Akademie für Raumentwicklung in der Leibniz-Gemeinschaft (ARL) - hat diese Fragen aufgegriffen und diskutiert. With the expansion of online trading, retail trade development has reached a new level in the process of ongoing structural change. Multi-channel concepts that combine offline and online retail are becoming increasingly important. In the course of digitalisation, "hybrid" types of enterprises that show significant differences from traditional retail stores are emerging. For providers unable to find answers to the challenges associated with this change, it will become more and more difficult to maintain their market position. The retail structures are changing - and that is changing our cities. In many town centres, the declining demand for retail space is already clearly visible today. The spatial effects depend on the specific situation at the respective location. The basic tendency is to expect a thinning out and polarisation of the urban centre systems: A few town centres with a special experiential character will assert themselves as retail locations and will be able to further distinguish themselves, in other locations the task of local supply will move into the focus in the future, and some town centres will lose their supply function. But even or especially in a digital world: Town centres are not a obsolescent model! On the contrary, the current developments can be the starting line for multifunctional locations to emerge that exude appeal for people and stay generally attractive. Fresh thinking and active engagement are needed to make this vision come true.

Additional file 1. Preoperative demographics and risk factors for aortic valve patients and mitral valve patients by valve type.

Lubricants are commonly used in metal forming processes to reduce the friction between the workpiece and the forming tool to protect semi-finished products and goods against corrosion and to reduce the load on the tool. One aim of environmentally friendly production technologies is to achieve dry forming without the use of lubricants. The goal of this project is to enable the dry forming of aluminum alloys during deep drawing by locally increasing the tool load capacity using customized tool coatings. The suitability of two types of carbon-based coatings, amorphous carbon and CVD diamond coatings will be investigated for dry contact with aluminum. In addition to coating, tribological effective microstructuring should improve the material flow and wear resistance of the used tools. The advantage of the amorphous carbon coatings is the deposition process, which enables a large area deposition as well as a good adhesion strength on steel substrates. Dry strip drawing and deep drawing tests with amorphous carbon coated tools showed higher friction coefficients compared to lubricated tests without any coating and a high adhesive wear. A reduction of the contact ratio from 100% to 87.5% resulted in a decrease of the sliding friction value by 20%. Dry tribological ball-on-plate tests of different coatings against aluminum showed that a polished microcrystalline CVD diamond coating is most promising to enable dry aluminum forming with a long lifetime of the coated tool. By in situ silicon carbide sublimation in a diamond deposition process, a possibility has been demonstrated for atmospheric CVD processes to reduce the electrical resistance of CVD diamond layers without the use of toxic gases. The electrical resistance of the coating could be reduced with a silicon doping concentration in the order of 1020 cm-3 in range between 104 O and 106 O. Electrical discharge machining of CVD diamond coatings has been made possible by silicon doping, which means that the specific resistance has been reduced to below 100 O∙cm.

The performance of hybrid metal composite parts strongly depends on the properties of the mechanical interface between the two components as well as on the deformation behavior. A combination of different joining mechanisms (e.g. adhesive bonding, mechanical form-fit) offers enhanced interface performance. This paper shows a novel interface concept based on form-fit elements induced by forming. Compared to other joining methods, the forming induced interface structure provides improved strength as well as energy absorption. Shear tests show an increase of up to 40% in shear strength and up to 78% in fracture energy compared to non-structured adhesive bondings.

Nachrichten aus Niedersachsens Urgeschichte, Bd. 64, Nr. 1 (1995): Nachrichten aus Niedersachsens Urgeschichte

In this study, the shaping and assembly behavior of adhesive polymer-metal-composites was investigated in an international cooperation using two step curable uretdione-polyester-based powder coatings (IPF development) which acts simultaneously as a reactive adhesive agent and as a high quality surface finish. To create the composite, a thermoplastic polyurethane (TPU) layer with good compatibility to the powder coating was over-molded onto a powder coated aluminum substrate. A polyamide (PA6) layer was over-molded on to the TPU layer to create a stiff composite structure with possibilities for further functionalization. The TPU-layer in between the metal substrate and the polymer top layer acts as a stress and strain compensation layer. These loads are caused by thermal expansion (under fluctuating temperatures) and external forces/deformation. Another key feature of the composite is the innovative process chain. The powder coating can resist high deformation and therefore the coating is suitable for a future application on to a metal substrate using a coil coating procedure. In addition, the coil could be easily implemented into a production line as a semi-finished product. The prefinished coated metal substrate could be formed (e.g. incremental forming, deep drawing) and inserted in the over-molding procedure. This overall shortened process chain allows not only an effective fabrication of pre-coated semi-finished materials and polymer-metal-joints in high quantities by saving process steps (e.g. cleaning steps, glue application) but also a higher versatility in the following composite production., Technologies for Lightweight Structures (TLS), Vol 1, No 2 (2017): Special Issue: 3rd International MERGE Technologies Conference (IMTC), 21st - 22nd September 2017, Chemnitz

In diesem Beitrag werden simulatorische und messtechnische EMV-Untersuchungen von Gleichspannungswandlern vorgestellt. Der Fokus liegt auf leitungsgeführten Störspannungen, ihre Abhängigkeit vom Schaltungslayout und ihre Unterdrückung durch Filterung. Der Simulationsprozess besteht aus kombinierten Feld- und Netzwerksimulationen. Zur Bewertung der Simulationsresultate werden zwei Prototypen gezeigt und verglichen, die unterschiedliche EMV-Eigenschaften aufweisen. Bei der Beurteilung der Resultate wird insbesondere Wert auf die Untersuchung gelegt, inwieweit einfache Schaltungssimulationen ausreichen, um leitungsgeführte Störspannungen korrekt vorherzusagen und wann aufwändigere Feldsimulationen notwendig sind.

In the present study, the surface conditions of workpieces used for dry-metal forming experiments were analyzed. Specifically, the effectiveness of different cleaning approaches was evaluated using x-ray photoelectron spectroscopy, infrared spectroscopy and wetting experiments. The best cleaning results were obtained using a CO2-based approach. CO2 acts as an effective solvent and as a result of the mechanical impact, it removes material from the surface. In fact, cleaning results were similar to those achieved by plasma cleaning. However, even simple cleaning with a towel and acetone left only a surface film of less than 100 nm. A residual oil film thickness below 100 nm on the work piece appears sufficient to mimic true dry-forming conditions in most cases. In order to determine cleanliness of surfaces used in dry-metal forming, an infrared spectroscopy-based oil film gauge along with a customized extended calibration curve turned out to provide for sufficiently accurate data.

Der Beitrag beschreibt die geometrische Optimierung hinsichtlich einer Minimierung der Impedanz und der Bestimmung abstoßender Kräfte von Leiterstrukturen einer akkreditierten Hochstromprüfanlage mittels elektromagnetischer Feldsimulation. Es wird die Methode der partiellen Netzwerkelemente vorgestellt und zur systematischen Optimierung eingesetzt.

In der Blechumformung erfolgt der Einsatz von Schmierstoffen beim Umformen, um die Prozessgrenzen durch die Reduktion von Reibung und Verschleiß zu erweitern. Die Reibung zwischen dem Werkzeug und dem Blechbauteil ist dabei für den Tiefziehprozess von wesentlicher Bedeutung. Aus wirtschaftlichen und ökologischen Gründen haben die Bauteilhersteller das Ziel den Einsatz von Schmierstoffen soweit wie möglich zu reduzieren bzw. vollständig auf Schmierstoffe zu verzichten. Mit Hilfe dieses Ansatzes lässt sich die Prozesskette verkürzen und es können nur begrenzt verfügbare Ressourcen in einem erheblichen Umfang eingespart werden. Die Vorteile einer Aktivteilstrukturierung bei geschmierten Umformprozessen durch die Ausbildung von Mikroschmiertaschen sind hinreichend bekannt. Jedoch lässt sich dieses Funktionsprinzip nicht auf die trockene Umformung übertragen. In diesem Fall wird durch die Strukturierung des Umformwerkzeuges der makroskopische Traganteil der Aktivteilflächen reduziert, wodurch wiederum das tribologische System beeinflusst wird. In dieser Veröffentlichung wird der Einfluss von Mikrostrukturierungen und Oberflächenbehandlungen (unbeschichtet / a-C:H:Si-beschichtet) auf den Gleitreibwert bei einer trockenen Umformung der Aluminiumlegierung EN AW-5182 untersucht und mit Referenzversuchen mit geschmierten, unstrukturierten Werkzeugaktivteilen verglichen. Mit Hilfe einer Streifenziehanlage wurde die tribologische Wirksamkeit der verschiedenen Oberflächenstrukturierungen und -behandlungen bestimmt. Im Rahmen der Untersuchung konnte nachgewiesen werden, dass der Gleitreibwert bei der trockenen Umformung durch eine Strukturierung des Ziehwerkzeuges und somit einer Reduzierung des makroskopischen Traganteils in einem gewissen Maß abgesenkt werden kann.

XP is a code oriented, light weight software engineering methodology, suited merely for small sized teams who develop software that relies on vague or rapidly changing requirements. Being very code oriented, the discipline of systems engineering knows it as approach of incremental system change. In this contribution, we discuss the enhanced version of a concept on how to extend XP on large scale projects with hundreds of software engineers and programmers, respectively. A previous version was already presented in [1]. The basic idea is to apply the "hierarchical approach", a management principle of reorganizing companies, as well as well known moderation principles to XP project organization. We show similarities between software engineering methods and company reorganization processes and discuss how the elements of the hierarchical approach can improve XP. We provide guidelines on how to scale up XP to very large projects e.g. those common in telecommunication industry and IT technology consultancy firms by using moderation techniques., 4 pages, 3 figures. arXiv admin note: substantial text overlap with arXiv:1409.6604

In den vergangenen Jahrzehnten bereicherten neben vielen Einzelbeiträgen zur regionalen Verbreitung von Gefäßpflanzen- und Kryptogamenarten vor allem auch systematische Kartierungsprojekte den aktuellen Kenntnisstand über die Flora des Bundeslandes Sachsen-Anhalt. Die vorliegenden Ergebnisse konnten nur durch die engagierte Mitarbeit ehrenamtlicher Spezialisten erzielt werden. Daran wird sich auch künftig nichts ändern, denn individuelle Verbundenheit mit der heimatlichen Landschaft, besondere Ortskenntnis und gediegene Kenntnis der Organismen sowie langjähriger, kontinuierlicher persönlicher Einsatz lassen sich durch eine kurzzeitige professionelle Erfassung nicht ersetzen.

XP is a code-oriented, light-weight software engineering methodology, suited merely for small-sized teams who develop software that relies on vague or rapidly changing requirements. Being very code-oriented, the discipline of systems engineering knows it as approach of incremental system change. In this contribution, we discuss the enhanced version of a concept on how to extend XP on large scale projects with hundreds of software engineers and programmers, respectively. Previous versions were already presented in [1] and [12]. The basic idea is to apply the "hierarchical approach", a management principle of reorganizing companies, as well as well-known moderation principles to XP project organization. We show similarities between software engineering methods and company reorganization processes and discuss how the elements of the hierarchical approach can improve XP. We provide guidelines on how to scale up XP to very large projects e.g. those common in telecommunication industry and IT technology consultancy firms by using moderation techniques., Comment: 7 pages, 4 figures

Die vegetationskundliche und strukturelle Zuordnung der Lebensraumtypen erfolgt nach der vorrangig von Braun-Blanquet entwickelten Vegetationsklassifizierung, einer hierarchischen Gliederung der Vegetationstypen (Syntaxonomie), die die Ebenen der Assoziation, des Verbandes, der Ordnung und der Klasse umfasst. Hierbei ist die Assoziation die grundlegende Einheit, in der die Pflanzengesellschaften zusammengefasst werden, die sich durch gleiche charakteristische Arten(gruppen)kombinationen auszeichnen. Der Verband vereinigt ähnliche Assoziationen. Das sind bereits umfassendere, jedoch standörtlich noch recht einheitliche Vegetationseinheiten. In Ordnungen werden ähnliche Verbände zusammengefasst. Die Klasse vereinigt ähnliche Ordnungen.

The application of a technical trading rule, which just provides long and short signals, requires the investor to decide upon the exposure to stake in each trade. Although this position sizing (or money management) crucially affects the risk and return characteristics, recent academic literature has largely ignored this effect, leaving reported results incomparable. This work systematically analyzes the impact of position sizing on timing strategies and clarifies the relation to the Kelly criterion, which proposes to bet relative fractions from the remaining gambling budget. Both erratic as well as different relative positions, i.e. fixed proportions of the remaining portfolio value, are compared for simple moving average trading rules. The simulation of parametrized return series allows systematically varying those asset price properties, which are most in uential on timing results: drift, volatility, and autocorrelation. The study reveals that the introduction of relative position sizing has a severe impact on trading results compared to erratic positions. In contrast to a standard Kelly framework, however, an optimal position size does not exist. Interestingly, smaller trading fractions deliver the highest risk-adjusted returns in most scenarios.

The application of a technical trading rule, which just provides long and short signals, requires the investor to decide upon the exposure to stake in each trade. Although this position sizing (or money management) crucially affects the risk and return characteristics, recent academic literature has largely ignored this effect, leaving reported results incomparable. This work systematically analyzes the impact of position sizing on timing strategies and clarifies the relation to the Kelly criterion, which proposes to bet relative fractions from the remaining gambling budget. Both erratic as well as different relative positions, i.e. fixed proportions of the remaining portfolio value, are compared for simple moving average trading rules. The simulation of parametrized return series allows systematically varying those asset price properties, which are most in uential on timing results: drift, volatility, and autocorrelation. The study reveals that the introduction of relative position sizing has a severe impact on trading results compared to erratic positions. In contrast to a standard Kelly framework, however, an optimal position size does not exist. Interestingly, smaller trading fractions deliver the highest risk-adjusted returns in most scenarios.

The often reported empirical success of trend-following technical timing strategies remains to be puzzling. In previous academic research, many authors admit some prediction power but struggle to substantiate their findings by referring vaguely to insufficient market effciency or unknown hidden patterns in asset price processes. We claim that empirical timing success is possible even in perfectly efficient markets but does not indicate prediction power. We prove this by systematically tracing back timing success to the statistical characteristics of the underlying asset price time series, which is modeled by standard stochastic processes. Five major impact factors are studied: return autocorrelation, trend, volatility and its clustering as well as the degree of market efficiency. We use trading rules based on different intervals of the simple moving average (SMA) as an example. These strategies are applied to simulated asset price data to allow for systematic parameter variations. Subsequently, we test the same strategies on real market data using non-parametric historical simulations and compare the results. Evaluation is done by an extensive selection of statistical-, return-, risk-, and performance figures calculated from the simulated return distributions.

The often reported empirical success of trend-following technical timing strategies remains to be puzzling. In previous academic research, many authors admit some prediction power but struggle to substantiate their findings by referring vaguely to insufficient market effciency or unknown hidden patterns in asset price processes. We claim that empirical timing success is possible even in perfectly efficient markets but does not indicate prediction power. We prove this by systematically tracing back timing success to the statistical characteristics of the underlying asset price time series, which is modeled by standard stochastic processes. Five major impact factors are studied: return autocorrelation, trend, volatility and its clustering as well as the degree of market efficiency. We use trading rules based on different intervals of the simple moving average (SMA) as an example. These strategies are applied to simulated asset price data to allow for systematic parameter variations. Subsequently, we test the same strategies on real market data using non-parametric historical simulations and compare the results. Evaluation is done by an extensive selection of statistical-, return-, risk-, and performance figures calculated from the simulated return distributions.