An alternative characterization of weak order dependence

Control dependence forms the basis for many program analyses, such as program slicing. Recent work on control dependence analysis has led to new definitions of dependence that can allow for reactive programs with their necessarily non-terminating computations. One important such definition is the definition of Weak Order Dependence, which was introduced to generalize classical control dependence for a Control Flow Graph (CFG) without end nodes. In this paper we show that for a CFG where all nodes are reachable from each other, weak order dependence can be expressed in terms of traditional control dependence where one node has been converted into an end node.     

Converting XML DTDs to UML diagrams for conceptual data integration

Extensible Markup Language (XML) is fast becoming the new standard for data representation and exchange on the World Wide Web, e.g., in B2B e-commerce. Modern enterprises need to combine data from many sources in order to answer important business questions, creating a need for integration of web-based XML data. Previous web-based data integration efforts have focused almost exclusively on the logical level of data models, creating a need for techniques that focus on the conceptual level in order to communicate the structure and properties of the available data to users at a higher level of abstraction. The most widely used conceptual model at the moment is the Unified Modeling Language (UML).

This paper presents algorithms for automatically constructing UML diagrams from XML DTDs, enabling fast and easy graphical browsing of XML data sources on the web. The algorithms capture important semantic properties of the XML data such as precise cardinalities and aggregation (containment) relationships between the data elements. As a motivating application, it is shown how the generated diagrams can be used for the conceptual design of data warehouses based on web data, and an integration architecture is presented. The choice of data warehouses and On-Line Analytical Processing as the motivating application is another distinguishing feature of the presented approach.     

Design and atomization properties for an inside-out type effervescent atomizer

Atomization of aqueous polymer solutions is a key step in the formulation of several pharmaceutical products. Droplet size control is essential in order to produce pharmaceutical products with the desired properties. The purpose of this paper is to investigate design issues for an inside-out type of effervescent atomizer used to spray water and aqueous solutions of polyvinylpyrrolidone (Kollidon® K-30) and hydroxypropyl methylcellulose (Pharmacoat® 603). The atomizer was operated at air-to-liquid mass ratios of 0.1, 0.3, and 0.5 and a feed pressure of 1172 kPa. Fluid viscosities ranged from 1 to 47 mPa.s. The influence of several atomizer design features was considered, including exit orifice length-to-diameter ratio, exit orifice diameter, the total area of the air injection holes, the distance between the air injection point and the exit orifice, the diameter of the mixing chamber, and the orientation of both air and liquid flows. Droplet size distributions were shown to vary significantly with the atomizer's exit orifice diameter, air injector design, and air injector distance to the exit orifice. In all cases air-to-liquid mass ratio played a key role in the mean droplet size. The design of the atomizer was shown to have the most pronounced effect on the mean droplet size at the lowest air-to-liquid mass ratios. Optimization of the atomizer design is very important in order to obtain small droplet sizes in pharmaceutical processes where the amount of air/gas should be minimized, e.g., closed-cycle spray drying and agglomeration processes.     

Reviews

Michal Kokowski, Copernicus’s Originality: Towards Integration of Contemporary Copernican Studies (Warsaw: Wydawnictwa Ihn Pan, 2004). 314 pp. pb. ISBN 83‐86062‐27‐4. Sharon E. Kingsland, The Evolution of American Ecology 1890–2000 (Baltimore: Johns Hopkins University Press, 2005). 313 pp. hc. $50. ISBN 0‐8018‐8171‐4. Graeme J.N. Gooday. The Morals of Measurement: Accuracy, Irony, and Trust in Late Victorian Electrical Practice (Cambridge: Cambridge University Press, 2004). xxv, 285 pp. hc. £55. ISBN 0‐521‐43098. Joan Vernet; Ramon Parés (eds.), La Ciència en la Història del Països Catalans. Vol. 1. Dels Àrabs al Renaixement (Valencia: University of Valencia, 2004). 630 pp. hc. €50. ISBN 84‐370‐ 6047‐8. Giuliano Pancaldi, Volta. Science and Culture in the Age of Enlightenment (Princeton and Oxford: Princeton University Press, 2003). 381 pp. hc. £32.50. ISBN 0‐691‐09685‐6. Wolfgang Lefèvre; Jürgen Renn; Urs Schoepfin (eds.), The Power of Images in Early Modern Science (Basel: Birkhäuser Verlag, 2003). 320 pp. pb. CHF 184, € 118. ISBN 3‐7643‐2434‐1. Olivier Darrigol, Worlds of Flow: A History of Hydrodynamics from the Bernoullis to Prandtl (Oxford: Oxford University Press, 2005). 356 pp. hc. L35.00. ISBN 0‐19‐856843‐6. Ad Meskens, Joannes della Faille s.j.: Mathematics, Modesty and Missed Opportunities (Brussel: Institut Historique Belge de Rome, 2005). 175 pp. hc. ISBN 90‐74461‐53‐0. Aant Elzinga; Torgny Nordin; David Turner; Urban Wråkberg (eds.), Antarctic Challenges. Historical and Current Perspectives on Otto Nordenskjöld’s Antartic Expedition 1901–1903 (Göteborg: Royal Society of Arts and Sciences, 2004). 330 pp. hc. $93. ISBN 91‐85252‐64‐6. Klaus‐Heinrich Peters, Schönheit, Exaktheit, Wahrheit: Der Zusammenhang von Mathematik und Physik am Beispiel der Geschichte der Distributionen (Berlin: GNT‐Verlag, 2005). 272 pp. pb. € 32.00. ISBN 3‐928186‐74‐4.     

Specification-based data reduction in dimensional data warehouses

Many data warehouses contain massive amounts of data, accumulated over long periods of time. In some cases, it is necessary or desirable to either delete “old” data or to maintain the data at an aggregate level. This may be due to privacy concerns, in which case the data are aggregated to levels that ensure anonymity. Another reason is the desire to maintain a balance between the uses of data that change as the data age and the size of the data, thus avoiding overly large data warehouses. This paper presents effective techniques for data reduction that enable the gradual aggregation of detailed data as the data ages. With these techniques, data may be aggregated to higher levels as they age, enabling the maintenance of more compact, consolidated data and the compliance with privacy requirements. Special care is taken to avoid semantic problems in the aggregation process. The paper also describes the querying of the resulting data warehouses and an implementation strategy based on current database technology.     

Mining Long, Sharable Patterns in Trajectories of Moving Objects

The efficient analysis of spatio-temporal data, generated by moving objects, is an essential requirement for intelligent location-based services. Spatio-temporal rules can be found by constructing spatio-temporal baskets, from which traditional association rule mining methods can discover spatio-temporal rules. When the items in the baskets are spatio-temporal identifiers and are derived from trajectories of moving objects, the discovered rules represent frequently travelled routes. For some applications, e.g., an intelligent ridesharing application, these frequent routes are only interesting if they are long and sharable, i.e., can potentially be shared by several users. This paper presents a database projection based method for efficiently extracting such long, sharable frequent routes. The method prunes the search space by making use of the minimum length and sharable requirements and avoids the generation of the exponential number of sub-routes of long routes. Considering alternative modelling options for trajectories, leads to the development of two effective variants of the method. SQL-based implementations are described, and extensive experiments on both real life- and large-scale synthetic data show the effectiveness of the method and its variants.

Are firms withdrawing from basic research? An analysis of firm-level publication behaviour in Germany

Scientometrics - Previous research has expressed concerns about firms engaging less in basic research. We contribute to this debate by studying trends in the scientific publishing activities of...     

Modular mutagenesis of a TEM-barrel enzyme: the crystal structure of a chimeric E.coli TIM having the eighth {beta}{alpha}-unit replaced by the equivalent unit of chicken TIM

Abstract The crystal structure of a hybrid Escherichia coli triosephosphateisomerase (TIM) has been determined at 2.8 Å resolution.The hybrid TIM (ETIM8CHI) was constructed by replacing the eighthß-unit of E.coli TIM with the equivalent unit of chickenTIM. This replacement involves 10 sequence changes. One of thechanges concerns the mutation of a buried alanine (Ala232 instrand 8) into a phenylalanine. The ETIM8CHI structure showsthat the A232F sequence change can be incorporated by a side-chainrotation of Phe224 (in helix 7). No cavities or strained dihedralsare observed in ETIM8CHI in the region near position 232, whichis in agreement with the observation that ETIM8CHI and E.coliTIM have similar stabilities. The largest CA (C-alpha atom)movements, 3 Å, are seen for the C-terminal end of helix8 (associated with the outward rotation of Phe224) and for theresidues in the loop after helix 1 (associated with sequencechanges in helix 8). From the structure it is not clear whythe k_cat of ETIM8CHI is 10 times lower than in wild type E.coliTIM