Catching-up and falling behind: knowledge spillover from American to German machine tool makers

In our days, German machine tool makers accuse their Chinese competitors of violating patent rights and illegally imitating German technology. A century ago, however, German machine tool makers used exactly the same methods to imitate American technology. To understand the dynamics of this catching-up process we use patent statistics to analyze firms' activities between 1877 and 1932. We show that German machine tool makers successfully deployed imitating and counterfeiting activities in the late 19th century and the 1920s to catchup to their American competitors. The German administration supported this strategy by stipulating a patent law that discriminated against foreign patent holders and probably also by delaying the granting of patents to foreign applicants. Parallel to the growing international competitiveness of German firms, however, the willingness to guarantee intellectual property rights of foreigners was also increasing because German firms had now to fear retaliatory measures in their own export markets when violating foreign property rights within Germany. --

Logic gates realized with spin dependent tunneling elements

Richter R. Logic gates realized with spin dependent tunneling elements. Bielefeld (Germany): Bielefeld University; 2002.The magnetoresistive effects are considered to improve existing electronic devices. The experimental feasibility of different concept's basic logic gates based on micron sized spin dependent tunneling (SDT) elements is verified, where the emphasize is put on field programmable spin-logic gates. The thesis is organized as follows. First, the physical principles of spin dependent tunneling which are important for logic are reviewed. Then the principle of digital logic based on SDT elements is explained. Beside the discusssion of concepts known from literature, new concepts are introduced. The feasibility of mask programmable and field programmable logic gates based on SDT elements with a minimal feature of 600 nm is shown. Characteristics of single SDT elements with impact on logic gates are investigated. The in-plane switching behavior of SDT element's soft magnetic (storage) layer is investigated for different shapes and aspect ratios down to a width of 600 nm. A systematic study on so-called astroids of micron-sized SDT elements is presented. Magnetostatic interactions of the magnetic layers within SDT elements are identified from these measurements. For spin-logic gates, critical factors for working logic gates are identified. The measured statistical fluctuations of the resistance-area product and tunneling magnetoresistance of the SDT elements forming a spin-logic gate are measured and the corresponding yield of working spin-logic gates is calculated. Furthermore, the benefit of the introduction of a reference layer system which is switchable (programmable) by a current on chip is discussed. Concretely, the reference layer system Ru/CoFe is investigated. The physical origin of the increase of the CoFe coercivity with increasing thickness of the Ru-buffer is investigated. Finally, the magnetic stability, which is a prerequisite for a working spin-logic, is investigated for different designs of the tunneling stack

Interactive Strategy-Based Validation of Behavioral Models

When behavioral models are derived automatically based on observed stakeholder interactions, requirements engineers need to validate whether the stakeholders agree with the synthesized behavioral models. Allowing stakeholders to experience such models through simulation and animation allows them to comment on, amend to and correct these models. However, to ensure an efficient stakeholder validation, the simulation has to be guided instead of confronting the user with random situations over and over again. In this paper, we present a strategy-driven simulator capable of guiding the execution of behavioral models based on graph transformations. By analyzing either the overall structure of a partial state space (look ahead) or by performing an in-depth analysis of the states therein, the simulator is able to determine which transformations should be executed next to continue on the most promising path through the overall state space. The discussed implementation is illustrated with a case study

Formation de membranes lipidiques sur support solide et assemblage bidimensionnel de protéines.

Les membranes lipidiques déposées sur support solide sont couramment utilisées comme modèle de membranes cellulaires et présentent des applications potentielles dans le domaine des biotechnologies. Ce travail de thèse a permis de caractériser, en détail, les processus de dépôt de liposomes et la formation des bicouches lipidiques supportées (SLBs) sur support de mica et de silice. L'influence de la charge des lipides et le rôle des ions Ca2+ dans la formation des SLBs ont été caractérisés. De plus nous avons réalisé une étude de la liaison spécifique et de l'autoassemblage de la protéine annexine A5 sur les SLBs. Les deux principales techniques de caractérisation utilisées pour cette étude sont la microscopie à force atomique (AFM) et la microbalance à cristal de quartz avec mesure de dissipation (QCM-D). Les obstacles techniques majeurs associés à l'imagerie par AFM des assemblages lipidiques ont été résolus. L'utilisation en parallèle des techniques QCM-D et AFM sur support de mica a été mise au point. La complémentarité de ces deux techniques a permis de caractériser la cinétique et de visualiser les structures intermédiaires formées lors des processus d'auto-organisation bidimensionnelle des lipides et des protéines.Supported lipid membranes (SLBs) are popular models of cell membranes with potential biotechnological applications. In this work we characterize the process of vesicle deposition and SLB-formation on solid supports in detail. In particular, the role of the support (mica and silica), the lipid charge and the presence of calcium as determinants of the lipid deposition pathway are highlighted. We exploit the SLBs as a biomimetic surface, in order to investigate the adsorption and twodimensional self-assembly of annexin A5, a membrane-binding protein. The main characterization techniques are the Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D) and Atomic Force Microscopy (AFM). These methods are demonstrated to be highly complementary, providing global kinetic information and local structural information on the self-organization processes simultaneously. In order to fully exploit the methods' complementarities, some technical obstacles had to be overcome. We identify and remedy artifacts associated with AFM-imaging of surface-confined lipid assemblies and combine QCM-D and AFM on identical supports, including mica

Purification, characterisation and cDNA sequencing of pyruvate decarboxylase from Zygosaccharomyces bisporus

Cells of the wild-type yeast strain Zygosaccharomyces bisporus CBS 702 form alpha-hydroxy ketones from aromatic amino acid precursors during fermentation, Pyruvate decarboxylase (PDC, E.C. 4.1.1.1), the key enzyme of this biotransformation catalysing the nonoxidative decarboxylation of pyruvate and other 2-oxo-acids, was purified and characterised. The active enzyme is homotetrameric (alpha(4)) with a molecular mass of about 244 kDa, Activation of PDC by its substrate pyruvate results in a sigmoidal dependence of the reaction rate from substrate concentration (apparent K-m value 1.73 mM; Hill coefficient 2.10). A cDNA library was screened using a PCR-based procedure, and a 1856 bp cDNA of PDC was identified and sequenced. The cDNA encodes a polypeptide of 563 amino acid residues (monomeric unit), Sequence alignments demonstrate high homologies (> 80%) to PDC genes from Saccharomyces cerevisiae, Kluyveromyces lactis and Kluyveromyces marxianus.DF

Akquisition und Repräsentation von technischem Wissen für Planungsaufgaben im Bereich der Fertigungstechnik

Im Bereich der Fertigungstechnik kann eine Fülle von Planungsaufgaben identifiziert werden, die für eine Bearbeitung mit Methoden der KI geeignet erscheinen. Das Projekt ARC-TEC am DFKI wendet die KADS-Methode zur systematischen Entwicklung von Expertensystemen an und erstellt Tools für alle Phasen dieser Entwicklung. Die Brauchbarkeit der entwickelten Methoden und Tools wird am Beispiel der Erstellung von Arbeitsplänen für die Drehbearbeitung demonstriert. Besonderes Augenmerk gilt dabei der expliziten Repräsentation des konkreten Expertenwissens und der Bearbeitung des gegebenen Problems in einer der Vorgehensweise des Experten möglichst naheliegenden Weise.In the area of production engineering many planning tasks can be found which seem well-suited to be tackled using AI-methodologies. The ARC-TEC project of the DFKI uses the model based KADS approach for a systematic development of expert systems and provides tools to support the different phases of this development. The generation of work plans for manufacturing by turning is used as an example to demonstrate the applicability of the different tools and methodologies. Special focus is upon the explicit representation of the concrete experts knowledge and the problem solving strategy which closely follows the way an expert solves the problem

Multivalent Recognition at Fluid Surfaces: The Interplay of Receptor Clustering and Superselectivity.

The interaction between a biological membrane and its environment is a complex process, as it involves multivalent binding between ligand/receptor pairs, which can self-organize in patches. Any description of the specific binding of biomolecules to membranes must account for the key characteristics of multivalent binding, namely, its unique ability to discriminate sharply between high and low receptor densities (superselectivity), but also for the effect of the lateral mobility of membrane-bound receptors to cluster upon binding. Here we present an experimental model system that allows us to compare systematically the effects of multivalent interactions on fluid and immobile surfaces. A crucial feature of our model system is that it allows us to control the membrane surface chemistry, the properties of the multivalent binder, and the binding affinity. We find that multivalent probes retain their superselective binding behavior at fluid interfaces. Supported by numerical simulations, we demonstrate that, as a consequence of receptor clustering, superselective binding is enhanced and shifted to lower receptor densities at fluid interfaces. To translate our findings into a simple, predictive tool, we propose an analytical model that enables rapid predictions of how the superselective binding behavior is affected by the lateral receptor mobility as a function of the physicochemical characteristics of the multivalent probe. We believe that our model, which captures the key physical mechanisms underpinning multivalent binding to biological membranes, will greatly facilitate the rational design of nanoprobes for the superselective targeting of cells.EU ETN grant 674979-NANOTRAN

THE RELATIONSHIP OF IS AND LAW - INSIGHTS INTO THE GERMAN ONLINE CAR REGISTRATION CASE

The mutual influence of Information Systems (IS) and law can be observed in projects of various industry sectors, but it seems to be prevalent in e-Government projects. Existing IS research in the field of e-Government suggests that the relationship between these two worlds has high potential for conflict and can be crucial for a project?s success. But an in-depth analysis of this specific relationship is still missing. We observed the German e-Government project ?online car registration? with a case study research approach. During the case analysis we developed a framework for the description and classification of the relationship of IS and law. The frameworks dimensions are the perceived influence direction (IS -\u3e Law, Law -\u3e IS, IS \u3c--\u3e Law), the perceived influence character (Positive, Negative, Ambivalent) and the perceived influence impact (Restrictive, Demanding, Enabling). We use this framework to structure the case and to derive project management recommendations on how to manage the relationship of IS and law in e-Government projects. The framework can further be used as a basis for a more in-depth systematic literature analysis or empirical case analyses

A Tandem Time--of--Flight Spectrometer for Negative--Ion/Positive--Ion Coincidence Measurements with Soft X-ray Excitation

We present a newly constructed spectrometer for negative--ion/positive--ion coincidence spectroscopy of gaseous samples. The instrument consists of two time--of--flight ion spectrometers and a magnetic momentum filter for deflection of electrons. The instrument can measure double and triple coincidences between mass--resolved negative and positive ions with high detection efficiency. First results include identification of several negative--ion/positive--ion coincidence channels following inner-shell photoexcitation of sulfur hexaflouride (SF$_6$)