Algorithms for the workflow satisfiability problem engineered for counting constraints

The workflow satisfiability problem (WSP) asks whether there exists an assignment of authorized users to the steps in a workflow specification that satisfies the constraints in the specification. The problem is NP-hard in general, but several subclasses of the problem are known to be fixed-parameter tractable (FPT) when parameterized by the number of steps in the specification. In this paper, we consider the WSP with user-independent counting constraints, a large class of constraints for which the WSP is known to be FPT. We describe an efficient implementation of an FPT algorithm for solving this subclass of the WSP and an experimental evaluation of this algorithm. The algorithm iteratively generates all equivalence classes of possible partial solutions until, whenever possible, it finds a complete solution to the problem. We also provide a reduction from a WSP instance to a pseudo-Boolean SAT instance. We apply this reduction to the instances used in our experiments and solve the resulting PB SAT problems using SAT4J, a PB SAT solver. We compare the performance of our algorithm with that of SAT4J and discuss which of the two approaches would be more effective in practice

Pattern backtracking algorithm for the workflow satisfiability problem with user-independent constraints

The workflow satisfiability problem (WSP) asks whether there exists an assignment of authorised users to the steps in a workflow specification, subject to certain constraints on the assignment. (Such an assignment is called valid.) The problem is NP-hard even when restricted to the large class of user-independent constraints. Since the number of steps k is relatively small in practice, it is natural to consider a parametrisation of the WSP by k. We propose a new fixed-parameter algorithm to solve the WSP with user-independent constraints. The assignments in our method are partitioned into equivalence classes such that the number of classes is exponential in k only. We show that one can decide, in polynomial time, whether there is a valid assignment in an equivalence class. By exploiting this property, our algorithm reduces the search space to the space of equivalence classes, which it browses within a backtracking framework, hence emerging as an efficient yet relatively simple-to-implement or generalise solution method. We empirically evaluate our algorithm against the state-of-the-art methods and show that it clearly wins the competition on the whole range of our test problems and significantly extends the domain of practically solvable instances of the WSP

Three species of monhysterids (Nematoda, Monhysterida) from mangrove forest of the Me Kong river estuary, Vietnam

Three new free-living nematode species of the order Monhysterida from Me Kong river estuaries of Vietnam are described. Daptonema brevisetosum sp. nov. resembles to Daptonema setosum (Bütschli, 1874), but differs from it by the relatively shorter outer labial setae, shorter spicules and shorter cervical and somatic setae. Subsphaerolaimus major sp. nov. similar to Subsphaerolaimus lamasus (Gerlach, 1956), Subsphaerolaimus gerlachi (Wieser, 1959) and Subsphaerolaimus litoralis Lorenzen, 1978, but differs from them by the longer body, longer spicules and presence of dorso-caudal apophysis of gubernaculum. Daptonema hirtum (Gerlach, 1957) is restored from synonymy of Daptonema setosum (Bütschli, 1874) and it is raised to range of valid species

Four new species of monhysterids (Nematoda: Monhysterida) from mangroves of the Mekong river estuaries of Vietnam

Four new free-living nematode species of the order Monhysterida from Me Kong River estuaries of Vietnam are described. Thalassomonhystera tenuis sp. nov. resembles to Thalassomonhystera pusilla (Boucher, Heleouët, 1977) but differs from it by the high, isolated labial region, longer outer labial setae, shorter oesophagus, shorter spicules, absence of gubernaculum’s dorso-caudal apophysis and presence of subterminal setae on the tip. Diplolaimelloides elegans sp. nov. resembles to Diplolaimelloides meyli Timm, 1961, but it differs in having longer and slender tail and vulva position located in more anterior body end. Sphaerotheristus supplementatus sp. nov. comes close to Sphaerotheristus parvus Gagarin, Nguyen Vu Thanh, 2006, it differs in having the longer and thinner body and papillae-shaped supplements in males. Terschellingia obesa sp. nov. similar to Terschellingia monohystera Wieser, Hopper 1967 and Terschellingia brevicaudata Ott, 1972, but it differs from T. monhystera in having shorter cephalic setae, others vulva position and absence of oesophagus basal bulb; it also differs from T. brevicaudata in having shorter body, shorter cephalic setae, shorter spicules and presence of one ovary

Two new species of the genus Halaphanolaimus De Man, 1876 (Nematoda: Leptolaimidae) from Can Gio mangrove forest, Vietnam

New brackish water nematode species Halaphanolaimus cangionensis sp.nov, and Halaphanolaimus rivalis sp.nov collected from Cangio mangrove forest, Hochiminh city of Vietnam are described. Halaphanolaimus cangionensis sp.nov is characterized by the absence of somatic and cervical setae, comparatively slender tail, presence of caudal apophysis of the gubernaculum and comparatively short spicules. New species Halaphanolaimus cangionensis sp.nov resembles to Halaphanolaimus harpaga Boucher, Bovee, 1972 and Halaphanolaimus luridus (Timm, 1963) but differs from H. harpaga by the absence of somatic and cervical setae, more anterior position of vulva, another structure of gubernaculums and other arrangement of precloacal supplements. The new species differs from H. luridus by the more slender tail, longer stoma, another structure of gubernaculums and shorter spicules. Halaphanolaimus rivalis sp.nov is characterized by the presence of somatic and servical setae, long spicules and pre-equatorial vulva. New species Halaphanolaimus rivalis sp.nov, resembles to Halaphanolaimus luridus (Timm, 1963) and L. lorenzeni Boucher, Bovee, 1972 but H. rivalis sp.n. differs from H. luridus by the presence of somatic and cervical setae, more wide labial region, longer stoma, shorter spicules. H. rivalis sp.n. differs from H. lorenzeni by the thicker body, longer stoma and longer spicules. Key to six valid species of the genus Halaphanolaimus are given.

Two new nematode species of the family Diplopeltidae Filipjev, 1918 (Nematoda, Araeolaimida) from coast of Vietnam

Two new species of free-living marine nematodes from West Sea (Gulf of Siam), coast of Vietnam, were described and illustrated. Diplopeltula obesa sp. n. differs from D. indica Gerlach, 1962 by possessing shorter and thicker body, comparatively longer tail and shorter cephalic setae, Campylaimus gracilis sp. n. resemble to C. minor Timm, 1961, but differs from the later by having an another shape of amphidial fovea, another position of mouth, longer body and shorter cephalic setae.Two new species of free-living marine nematodes from West Sea (Gulf of Siam), coast of Vietnam, were described and illustrated. Diplopeltula obesa sp. n. differs from D. indica Gerlach, 1962 by possessing shorter and thicker body, comparatively longer tail and shorter cephalic setae, Campylaimus gracilis sp. n. resemble to C. minor Timm, 1961, but differs from the later by having an another shape of amphidial fovea, another position of mouth, longer body and shorter cephalic setae

Enhanced electrical properties of ferroelectric thin films by ultraviolet radiation

Published versio

ПРОГРАММНАЯ РЕАЛИЗАЦИЯ ФОРМИРОВАНИЯ ЦВЕТОГРАФИЧЕСКИХ КАРТ ДЛЯ ОЦЕНКИ ИННОВАЦИОННЫХ ПРОЕКТОВ РАННИХ СТАДИЙ РАЗВИТИЯ

The article deals with functional program that allows to generate a visualrepresentation of the shareholder tothe innovative project early stage ofdevelopment, formed a color-based cards.В статье рассматривается функциональнаяпрограмма, позволяющаяформировать визуальное представление о представляемом на рассмотрение инновационномпроектераннейстадии развития, формируемое в виде цветографической карты