Konzeption einer Kollaborationsplattform für die zwischenbetriebliche Softwareerstellung

The development of business application software is increasingly based on the development of different components by various suppliers. In the next step, system vendors integrate these components. Hereby, inter-organizational collaboration becomes more and more important for the software industry. In order to strengthen the value-added processes within these established software supply chains, the Ministry of Economic Affairs in Baden-Württemberg funded the project TASK that aims at fostering inter-organizational design, integration, and implementation of software components. The present article on the one hand provides an insight into the structure as well as the progress of this project and, on the other hand, presents academic research results in terms of an empirical analysis of barriers and drivers of interorganizational collaboration and of the purposeful design of a collaboration platform. The article concludes with a summary and a discussion of current and upcoming issues in establishing and sustaining inter-organizational collaboration structures within the software industry.     

Aus der Praxis der Stichproben-Inventur in einem Industrieunternehmen

Zusammenfassung Die Stichprobeninventur ist eine spezielle Form der Inventur, bei der nur ein geringer Teil des Vorratsvermögens körperlich aufgenommen werden muß. Sie bietet wesentliche Rationalisierungsmöglichkeiten gegenüber der herkömmlichen Vollinventur. Neben dem statistischen Verfahren wird über das organisatorische Umfeld, die EDV-mäßige Abwicklung, die Einführung und die Erfahrungen in einem Unternehmen der elektrotechnischen Industrie berichtet, in dem die Stichprobeninventur seit 1976 untersucht und inzwischen in neun Lagern eingesetzt wird.

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Summary Sampling methods taken for the yearly inventory can lead to important savings. Besides the statistical method the problems of application are discussed: The special organization of the company, the processing by EDP, the way to introduce the procedure etc. The paper is based on the original data of a company for electrical engineering. The sampling method for the inventory has been analysed since 1976; it is now used for the yearly inventory of nine stocks.

     

Calcite Reinforced Silica–Silica Joints in the Biocomposite Skeleton of Deep‐Sea Glass Sponges

The hierarchically structured glass sponge Caulophacus species uses the first known example of a silica and calcite biocomposite to join the spicules of its skeleton together. In the stalk and body skeleton of this poorly known deep‐sea glass sponge siliceous spicules are modified by the addition of conical calcite seeds, which then form the basis for further silica secretion to form a spinose region. Spinose regions on adjacent spicules are then joined by siliceous crosslinks, leading to unusually strong cross‐spicule linkages. In addition to the biomaterials implications it is now clear, from this first record of a biomineral other than silica, that the hexactinellid sponges are capable of synthesizing calcite, the ancestral skeletal material. We propose that, while the low concentrations of calcium in deep sea waters drove the evolution of silica skeletons, the brittleness of silica has led to retention of the more resilient calcite in very low concentrations at the skeletal joints.     

Free choice systems have home states

Summary This paper contains a proof that live and safe free choice Petri nets have home states. Home states are ones which can be reached from every successor state of the initial state. Liveness means that all actions remain executable, and safeness means that all capacities are finite. The result is interesting because it may help in the analysis of behavioural properties of complex systems. The existence of home states is a strong property which (as we will also show) fails to hold for a slightly generalised class of nets.     

Fairness and conspiracies

We define a hierarchy of fairness postulates; k-fairness (∞-fairness) means the absence of any infinite execution in which some transition occurs only finitely often but is enabled infinitely often by some sequence of length ? k (of unrestricted length, respectively).We show (i) that for Petri nets in general, ∞-fairness equals k-fairness for all k, and (ii) that for a large subclass of nets, (k+1)-fairness equals k-fairness for all k. The transferral of these results to concurrent programs is also discussed.     

Die Entwicklung des virtuellen Speichers

Ohne Zusammenfassung     

Silica biomineralization in diatoms: the model organism Thalassiosira pseudonana

After complete genome sequencing, the diatom Thalassiosira pseudonana has become an attractive model organism for silica biomineralization studies. Recent progress, especially with respect to intracellular silicic acid processing, as well as to the natures of the biomolecules involved in diatom cell wall formation, is described. On the one hand, considerable progress has been made with respect to silicon uptake by special proteins (SITs) from the surrounding water, as well as to the storage and processing of silicon before cell division. On the other hand, the discovery and characterisation of remarkable biomolecules such as silaffins, polyamines and--quite recently--of silacidins in the siliceous cell walls of diatoms strongly impacts the growing field of biomimetic materials synthesis.     

Consecutive conformational transitions and deaggregation of multiple-helical poly(diacetylene)s

The polymerization of diacetylene macromonomers based on oligopeptide-polymer conjugates yields conjugated polymers with multiple-helical quaternary structures. These polymers exhibit a rich dynamic folding behavior upon the addition of protic cosolvents. Thus, a helix-helix transition under helix-sense inversion was followed by a reversible helix-coil transition. Both transitions involved changes in the aggregation state of the multiple-helical superstructures. The resemblance of the observed consecutive and cooperative conformational transitions to those of biopolymers underlines the importance of supramolecular self-assembly as a pathway toward biofunctional materials with optoelectronic activity.     

Mechanical properties of single cells by high-frequency time-resolved acoustic microscopy

In this paper, we describe a new, high-frequency, time-resolved scanning acoustic microscope developed for studying dynamical processes in biological cells. The new acoustic microscope operates in a time-resolved mode. The center frequency is 0.86 GHz, and the pulse duration is 5 ns. With such a short pulse, layers thicker than 3 microm can be resolved. For a cell thicker than 3 microm, the front echo and the echo from the substrate can be distinguished in the signal. Positions of the first and second pulses are used to determine the local impedance of the cell modeled as a thin liquid layer that has spatial variations in its elastic properties. The low signal-to-noise ratio in the acoustical images is increased for image generation by averaging the detected radio frequency signal over 10 measurements at each scanning point. In conducting quantitative measurements of the acoustic parameters of cells, the signal can be averaged over 2000 measurements. This approach enables us to measure acoustical properties of a single HeLa cell in vivo and to derive elastic parameters of subcellular structures. The value of the sound velocity inside the cell (1534.5 +/- 33.6 m/s) appears to be only slightly higher than that of the cell medium (1501 m/s).