A Polynomial Translation of pi-calculus FCPs to Safe Petri Nets

We develop a polynomial translation from finite control pi-calculus processes to safe low-level Petri nets. To our knowledge, this is the first such translation. It is natural in that there is a close correspondence between the control flows, enjoys a bisimulation result, and is suitable for practical model checking.Comment: To appear in special issue on best papers of CONCUR'12 of Logical Methods in Computer Scienc

Slimming down Petri Boxes: Compact Petri Net Models of Control Flows

We look at the construction of compact Petri net models corresponding to process algebra expressions supporting sequential, choice, and parallel compositions. If "silent" transitions are disallowed, a construction based on Cartesian product is traditionally used to construct places in the target Petri net, resulting in an exponential explosion in the net size. We demonstrate that this exponential explosion can be avoided, by developing a link between this construction problem and the problem of finding an edge clique cover of a graph that is guaranteed to be complement-reducible (i.e., a cograph). It turns out that the exponential number of places created by the Cartesian product construction can be reduced down to polynomial (quadratic) even in the worst case, and to logarithmic in the best (non-degraded) case. As these results affect the "core" modelling techniques based on Petri nets, eliminating a source of an exponential explosion, we hope they will have applications in Petri net modelling and translations of various formalisms to Petri nets

INVESTIGATION OF TECHNOLOGICAL PROPERTIES OF FOUR-TYPE TRITICALE SEED OF DIFFERENT FRACTIONS

Triticale is a promising agricultural crop. The increased content of protein, balanced by the amino acid composition, advantageously distinguishes triticale seed for peeled grains and food concentrates production. Seed cleaning is an important technological operation of food productions, but setting regimes of seed-cleaning equipment for processing triticale seed need specification today. The aim of this work is to study geometric and physical characteristics of four-type triticale seed and elaboration of recommendations as to its cleaning and fractionating. There was studied the fractional composition of four-type triticale seed. The comparative analysis of its length, width and thickness in samples of different sorts and fractions was realized. The dependence of geometric properties of triticale seed on sort is reliable. Fractionating reliably influences the change of the mass index of 1000 seeds, changing from 65,2 g to 25,8 g. The mass index of 1000 seeds essentially differs between studied sorts. Such properties are inherent to seed fractions, obtained by a sieve of 3,2–20 mm and 3,0–20 mm, that are recommended to be called big seeds. Fractions, obtained by a sieve of 2,0–20 and 2,2–20 are analogously similar. Properties of the middle fraction, obtained by sieves of 2,4–20; 2,6–20; 2,8–20 essentially changed, depending on sort. The elaborated recommendations may be used at choosing cleaning regimes for triticale seed on sieve and sieve-air separators

INVESTIGATION OF TECHNOLOGICAL PROPERTIES OF FOUR-TYPE TRITICALE SEED OF DIFFERENT FRACTIONS

Triticale is a promising agricultural crop. The increased content of protein, balanced by the amino acid composition, advantageously distinguishes triticale seed for peeled grains and food concentrates production. Seed cleaning is an important technological operation of food productions, but setting regimes of seed-cleaning equipment for processing triticale seed need specification today. The aim of this work is to study geometric and physical characteristics of four-type triticale seed and elaboration of recommendations as to its cleaning and fractionating. There was studied the fractional composition of four-type triticale seed. The comparative analysis of its length, width and thickness in samples of different sorts and fractions was realized. The dependence of geometric properties of triticale seed on sort is reliable. Fractionating reliably influences the change of the mass index of 1000 seeds, changing from 65,2 g to 25,8 g. The mass index of 1000 seeds essentially differs between studied sorts. Such properties are inherent to seed fractions, obtained by a sieve of 3,2–20 mm and 3,0–20 mm, that are recommended to be called big seeds. Fractions, obtained by a sieve of 2,0–20 and 2,2–20 are analogously similar. Properties of the middle fraction, obtained by sieves of 2,4–20; 2,6–20; 2,8–20 essentially changed, depending on sort. The elaborated recommendations may be used at choosing cleaning regimes for triticale seed on sieve and sieve-air separators

Multiscale magnetic underdense regions on the solar surface: Granular and Mesogranular scales

The Sun is a non-equilibrium dissipative system subjected to an energy flow which originates in its core. Convective overshooting motions create temperature and velocity structures which show a temporal and spatial evolution. As a result, photospheric structures are generally considered to be the direct manifestation of convective plasma motions. The plasma flows on the photosphere govern the motion of single magnetic elements. These elements are arranged in typical patterns which are observed as a variety of multiscale magnetic patterns. High resolution magnetograms of quiet solar surface revealed the presence of magnetic underdense regions in the solar photosphere, commonly called voids, which may be considered a signature of the underlying convective structure. The analysis of such patterns paves the way for the investigation of all turbulent convective scales from granular to global. In order to address the question of magnetic structures driven by turbulent convection at granular and mesogranular scales we used a "voids" detection method. The computed voids distribution shows an exponential behavior at scales between 2 and 10 Mm and the absence of features at 5-10 Mm mesogranular scales. The absence of preferred scales of organization in the 2-10 Mm range supports the multiscale nature of flows on the solar surface and the absence of a mesogranular convective scale

Efficient Automatic Resolution of Encoding Conflicts Using STG Unfoldings

Synthesis of asynchronous circuits from Signal Transition Graphs (STGs) involves resolution of state encoding conflicts by means of refining the STG specification. In this paper, a technique for resolving such conflicts by means of insertion of new signals is proposed. It is based on conflict cores, i.e. sets of transitions causing encoding conflicts, which are represented at the level of finite and complete prefixes of STG unfoldings. The experimental results show significant improvements over the state space based approach in terms of runtime and memory consumption, as well as some improvements in the quality of the resulting circuit