WEB service interfaces for inter-organisational business processes an infrastructure for automated reconciliation

For the majority of front-end e-business systems, the assumption of a coherent and homogeneous set of interfaces is highly unrealistic. Problems start in the back-end, with systems characterised by a heterogeneous mix of applications and business processes. Integration can be complex and expensive, as systems evolve more in accordance with business needs than with technical architectures. E-business systems are faced with the challenge to give a coherent image of a diversified reality. Web services make business interfaces more efficient, but effectiveness is a business requirement of at least comparable importance. We propose a technique for automatic reconciliation of the Web service interfaces involved in inter-organisational business processes. The working assumption is that the Web service front-end of each company is represented by a set of WSDL and WSCL interfaces. The result of our reconciliation method is a common interface that all the parties can effectively enforce. Indications are also given on ways to adapt individual interfaces to the common one. The technique was embodied in a prototype that we also present

Maximum Volume Subset Selection for Anchored Boxes

Let $B$ be a set of $n$ axis-parallel boxes in $\mathbb{R}^d$ such that each box has a corner at the origin and the other corner in the positive quadrant of $\mathbb{R}^d$, and let $k$ be a positive integer. We study the problem of selecting $k$ boxes in $B$ that maximize the volume of the union of the selected boxes. This research is motivated by applications in skyline queries for databases and in multicriteria optimization, where the problem is known as the hypervolume subset selection problem. It is known that the problem can be solved in polynomial time in the plane, while the best known running time in any dimension $d \ge 3$ is $\Omega\big(\binom{n}{k}\big)$. We show that: - The problem is NP-hard already in 3 dimensions. - In 3 dimensions, we break the bound $\Omega\big(\binom{n}{k}\big)$, by providing an $n^{O(\sqrt{k})}$ algorithm. - For any constant dimension $d$, we present an efficient polynomial-time approximation scheme

Hydration and the true water content of swellable clay minerals

Water affects biological, chemical and transportation processes as well as mechanical properties of soils. Thereby, clay mineral content determines the moisture balance of soils. In-situ moisture measurements depend on reliable calibration based on the true water content. Drying the soil at 105 °C is the most common procedure to determine the water content although it is known, swellable clay minerals retain hydration water up to much higher temperatures. The amplified water uptake and retention by swellable clay minerals results from hydration of interlayer cations. Thereby, the water binding mechanisms are complex due to structural heterogeneity and are determined by layer charge density and location of substitutions. While several experimental studies deal with the maximum water uptake of selected smectites and heating conditions for full dehydration a comprehensive understanding of the relation between the structure of smectites and water uptake/release is still missing. The Na-saturated smectite / water interface for the montmorillonite-beidellite series is investigated in the present work within the density functional theory (DFT). Layer charge is varied between 0.125 and 0.5 per formula unit [O10(OH)2] by substitution of Al3+ by Mg2+ in the octahedral sheet (montmorillonites) and by substitution of Si4+ by Al3+ in the tetrahedral sheets (beidellites). Starting from the water free supercells (with integer molar ratios), the number of water molecules is increased discretely. Stable hydration states (1H to 3H) do not necessarily correspond to the formation of water layers (1W to 3W) in the interlayer, which is deduced from the development of the basal spaces during hydration. With the help of ab initio thermodynamics, the energy states are related to temperature, and partial pressure of H2O and the resulting phase diagrams revealed hydration state in dependence of relative humidity (RH) as well as necessary temperatures for full dehydration to determine the true water content. Thereby it was shown that 2:1 layer silicates with a layer charge of 0.125 are swellable but reach only the 1H state even at 100% RH, but the removal of water molecules from the interlayer requires temperatures >110 °C and partial pressures of water <100 Pa. In contrast water uptake of smectites with layer charge 0.375 requires RH of >11% at room temperature, but dehydration occurs at moderate heating

A Simplified Cellular Automaton Model for City Traffic

We systematically investigate the effect of blockage sites in a cellular automaton model for traffic flow. Different scheduling schemes for the blockage sites are considered. None of them returns a linear relationship between the fraction of ``green'' time and the throughput. We use this information for a fast implementation of traffic in Dallas.Comment: 12 pages, 18 figures. submitted to Phys Rev

DDFT calibration and investigation of an anisotropic phase-field crystal model

The anisotropic phase-field crystal model recently proposed and used by Prieler et al. [J. Phys.: Condens. Matter 21, 464110 (2009)] is derived from microscopic density functional theory for anisotropic particles with fixed orientation. Further its morphology diagram is explored. In particular we investigated the influence of anisotropy and undercooling on the process of nucleation and microstructure formation from atomic to the microscale. To that end numerical simulations were performed varying those dimensionless parameters which represent anisotropy and undercooling in our anisotropic phase-field crystal (APFC) model. The results from these numerical simulations are summarized in terms of a morphology diagram of the stable state phase. These stable phases are also investigated with respect to their kinetics and characteristic morphological features.Comment: It contain 13 pages and total of 7 figure