Higher-Order Nets for Mobile Policies

Since the early 80's the combination of Petri nets and rule-based transformations has been extensively researched to obtain new concepts and results. In this paper we consider rules as tokens leading to the concept of higher-order nets for mobile policies. The rules are used on the one hand for the specification of policy rules and on the other hand for the modification of policy rules, i.e. for the definition of new rules by reusing existing rules. So the higher-order net models distribution and modification of policy rules in a systematic and structured way. We give HasCasl-specifications of rules and (local) transformations in the sense of the double-pushout approach and illustrate our concept by a small system inspired by the case study of a tax refund process [E. Bertino, E. Ferrari, E., and V. Atluri. The Specification and Enforcement of Authorization Constraints in Workflow Management Systems. ACM Transactions on Information and System Security 2 (1) (1999) 65–104].     

Topotatic-Like Phase Transformation of Amorphous Lead Titanate to Cubic Lead Titanate

The crystallization process of lead titanate (PT) prepared using the polymeric precursor method was investigated using X-ray diffractometry, Raman spectroscopy, electron microscopy, and X-ray absorption spectroscopy techniques. The results showed that amorphous PT was formed by an O–Ti–O structure composed of fivefold and sixfold oxygen-coordinated titanium. The local structure of the amorphous PT phase was similar to that of the cubic PT phase, i.e., similar coordination number and similar bond lengths, leading to a topotactic-like transformation during the phase transformation from amorphous to cubic perovskite PT. Because of the low crystallization temperature, every transformation observed during the crystallization process was associated with a short-range rearrangement process.     

Microstructure evolution during annealing of an amorphous TiAl sheet

An amorphous, 150 μm thick freestanding sheet of a TiAl-based alloy was produced by physical vapor deposition (PVD). The following phase transformations were observed after different stages of crystallization of the amorphous sheet and analyzed using differential thermal analysis, X-ray diffraction, and transmission electron microscopy: amorphous→body centered cubic (β)→hexagonal close-packed ()?→tetragonal (γ)+ordered ₂. The β phase was formed as near-spherical particles that were evenly distributed in the amorphous phase and the size of these particles was approximately 90 nm. Formation of the phase by decomposition of β and the remaining amorphous phases led to a very fine feathery-like microstructure arranged in colonies of approximately 100 nm in size. Interface boundaries between the phase particles were poorly defined. The transformation of the metastable phase into a mixture of the γ and ₂ phases led to formation of an equiaxed γ-grain structure with the grain size of approximately 150 nm.     

Modelling of Transformations in TRIP Steels

Industrial processing of low‐alloy Transformation Induced Plasticity (TRIP) steels involves various stages of heat‐treating, such as Intercritical Annealing (IA) and Bainitic Isothermal Treatment (BIT), in order to produce a dispersion of retained austenite (γ_R) particles and bainite (α_B) in a ferritic matrix (α). Retained austenite then transforms to martensite (α′) during forming processes undergone by the steel. In the present work an effort was made to model these stages of processing, i.e. IA, BIT and the γ_R→α′ strain‐induced transformation. Simulation of heat‐treatment stages was implemented using computational kinetics methods. Investigation of the strain‐induced gM_R→α′ transformation kinetics was performed by means of a simple analytical model. Simulation of IA and comparison with available experimental data showed that the amount of austenite (γ) forming during IA reaches the values predicted by thermodynamic equilibrium only at high annealing temperatures (>825°C). It was also observed that kinetic and thermodynamic predictions set a lower and an upper limit, respectively, within which the actual amount of austenite experimentally observed is contained. Results from the simulation of the BIT indicated considerable carbon enrichment, and thus stabilization of γ_R, in agreement with recent experimental observations. As regards the strain‐induced gM_R→α′ transformation, the analytical model employed in the present work was fitted to available experimental results, showing reasonably good adaptation to the kinetic behaviour of the microstructure during plastic deformation.     

Performance Analysis of Linear Algebraic Functions Using Reconfigurable Computing

This paper introduces a new mapping of geometrical transformation on the MorphoSys (M1) reconfigurable computing (RC) system. New mapping techniques for some linear algebraic functions are recalled. A new mapping for geometrical transformation operations is introduced and their performance on the M1 system is evaluated. The translation and scaling transformation addressed in this mapping employ some vector–vector and vector–scalar operations [6 and 7]. A performance analysis study of the M1 RC system is also presented to evaluate the efficiency of the algorithm execution. Numerical examples were simulated to validate our results, using the MorphoSys mULATE program, which emulates M1 operations.     

Embodied spatial transformations: "Body analogy" for the mental rotation of objects.

The cognitive advantage of imagined spatial transformations of the human body over that of more unfamiliar objects (e.g., Shepard-Metzler [S-M] cubes) is an issue for validating motor theories of visual perception. In 6 experiments, the authors show that providing S-M cubes with body characteristics (e.g., by adding a head to S-M cubes to evoke a posture) facilitates the mapping of the cognitive coordinate system of one's body onto the abstract shape. In turn, this spatial embodiment improves object shape matching. Thanks to the increased cohesiveness of human posture in people's body schema, imagined transformations of the body operate in a less piecemeal fashion as compared with objects (S-M cubes or swing-arm desk lamps) under a similar spatial configuration, provided that the pose can be embodied. If the pose cannot be emulated (covert imitation) by the sensorimotor system, the facilitation due to motoric embodiment will also be disrupted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A method of synthesizing a discrete similarity function for increasing measurement processing quality

A precision method has been developed for solving optimal-reception equations on the basis of discrete Fourier transformation. The method provides for synthesizing efficient devices for signal observation and parameter estimation for use in measuring instruments. __________ Translated from Izmeritel’naya Tekhnika, No. 3, pp. 13–15, March, 2007.     

Forms of sulphur in sheep excreta and their fate after application on to pasture soil

Sheep were fed ³⁵S-labelled grass/clover herbage and the excreta was collected. About 74% of excretal S was in the form of urine and the remainder was in dung. Sulphate-S accounted for 74% of the urine S and the remainder was in Hi-reducible form. In dung, 80% of the S was C-bonded organic S and 20% was present as sulphate-S. ³⁵S-labelled dung was applied to undisturbed pasture microplots and the degradation and S release followed over a 9 month period under glasshouse conditions. During the first 34 days about 24% of ³⁵S was leached from the dung, mainly as sulphate-S and possibly some labile organic S. The C-bonded S in the dung was notably resistant to mineralisation. Only 14% of the applied ³⁵S was recovered by pasture plants. ³⁵S-labelled urine with either a high (1130 mg S litre^?1) or a low S concentration (280 mg S litre^?1) was applied in the field and its fate followed over a 10 month period. During the experiment 57 and 79% of the applied ³⁵S was recovered in pasture herbage in the high and low urine treatments, respectively. ³⁵S was also incorporated into soil organic matter and this reached a peak about 120 days after urine application when 52 and 30% of applied S had been incorporated in the high and low urine S treatments, respectively. With time, these levels declined as about 50% of the organic ³⁵S was mineralised and subsequently absorbed by the pasture plants. The results demonstrate that excreted S is recycled rapidly in pasture soils when it originates from urine. However, the bulk of S in dung appears to be relatively inert at least over a 9 month period.     

On Formal Models in Investigating Critical Velocities (Illustrated by Lorentz's Transformations)

A new model is proposed for investigation of relations between the coordinates of an object that moves relative to one coordinate system and is motionless relative to another one. Within the framework of this model, the interpretation of the so-called relativistic consequences of the Lorentz transformation laws differs radically from the well-known one.