In the linear system Ax = b the points x are sometimes constrained to lie in a given subspace S of column space of A. Drazin inverse for any singular or nonsingular matrix, exist and is unique. In this paper, the singular consistent or inconsistent constrained linear systems are introduced and the effect of Drazin inverse in solving such systems is investigated. Constrained linear system arise ...

A stabbing line for a set of convex polyhedra is extremal if it passes through four edges and is tangent to the polyhedra containing those edges. In this paper we present three constructions of convex polyhedra with many extremal lines. The rst construction shows (n 2) extremal stabbing lines constrained to meet two skew lines. The second shows (n 4) extremal lines which are tangent to two poly...

Conventional work ow functionality like task sequencing, split parallelism, join synchronisation and iteration have proven e ective for business process automation and have widespread support in current work ow products. One the other hand, newer requirements for work ows are encountered in practice, opening grave uncertainties about the extensions for current languages. Di erent concepts, alth...

The mol-ecule of the title compound C7H8N4O·0.5H2O, alternatively called (E)-1-(pyridin-4-yl-methyl-ene)semi-carb-azide hemihydrate, is in the E conformation and is almost planar; the r.m.s. deviation of the positions of the atoms of the pyridine ring from the best-fit plane is 0.0039 Å. The C, N and O atoms of the rest of the mol-ecule sits close on this plane with a largest deviation of 0.115...

In the title compound, C(4)H(6)N(3) (+)·H(2)O(4)P(-)·H(2)O, the pyrimidin-ium ring is essentially planar, with an r.m.s. deviation of 0.0016 Å. In the structure, pairs of symmetry-related anions are connected into centrosymmetric clusters via strong O-H⋯O hydrogen bonds forming six-membered rings with an R(2) (2)(6) motif. These clusters are inter-connected via water mol-ecules through OW-H⋯O h...

A new concept, fuzzy segments, is introduced which allows for exible segmentation of discrete curves, so taking into account some noise in them. Relying on an arithmetic approach of discrete lines, it generalizes them, admitting that some points are missing. Thus, a larger class of objects is considered. A very e cient detection algorithm for fuzzy segments and its application to curve segmenta...

Multimedia applications involving digital audio and/or digital video transmissions require strict QoS constraints (end-to-end delay bound, bandwidth availability, packet loss rate, etc.) to be met by the network. To guarantee the real-time delivery of packets satisfying these constraints, a real-time channel 4] needs to be established before the transmission of packets of a connection can begin...

Global transaction management in a distributed database system requires cooperation from local sites to ensure the consistent and reliable execution of global transactions. In a heterogeneous distributed database environment, various local sites make con icting assertions of autonomy over the execution of global transactions. The exible transaction approach increases the failure resilience of g...

Abstract Combining spatially localized X-ray diffraction (XRD) with microtomography (XMT) enables the mapping of micro- and nanoscale structures simultaneously. The combination these methods results in a powerful tool when considering structural studies hierarchical materials, allowing one to couple relationships connections at various scales. In this study, XMT was used map anatomy cellular 3D...

English) The Internet of Things is a rapidly evolving eld of high-end technology and research. Its security is vital to the reliability and safety of the future everyday communications. The DTLS protocol is a default protocol to assure security for unicast communication. A DTLS record layer extension for multicast in constrained environments is being designed to assure security for multicast. H...