A generalization of analytic deduction via labelled deductive systems. Part I: Basic substructural logics

In this series of papers we set out to generalize the notion of classical analytic deduction (i.e., deduction via elimination rules) by combining the methodology of labelled deductive systems (LDS) with the classical systemKE. LDS is a unifying framework for the study of logics and of their interactions. In the LDS approach the basic units of logical derivation are not just formulae butlabelled formulae, where the labels belong to a given labelling algebra. The derivation rules act on the labels as well as on the formulae, according to certain fixed rules of propagation. By virtue of the extra power of the labelling algebras, standard (classical or intuitionistic) proof systems can be extended to cover a much wider territory without modifying their structure. The systemKE is a new tree method for classical analytic deduction based on analytic cut.KE is a refutation system, like analytic tableaux and resolution, but it is essentially more efficient than tableaux and, unlike resolution, does not require any reduction to normal form.We start our investigation with the family of substructural logics. These are logical systems (such as Lambek's calculus, Anderson and Belnap's relevance logic, and Girard's linear logic) which arise from disallowing some or all of the usual structural properties of the notion of logical consequence. This extension of traditional logic yields a subtle analysis of the logical operators which is more in tune with the needs of applications. In this paper we generalize the classicalKE system via the LDS methodology to provide a uniform refutation system for the family of substructural logics.The main features of this generalized method are the following: (a) each logic in the family is associated with a labelling algebra; (b) the tree-expansion rules (for labelled formulae) are the same for all the logics in the family; (c) the difference between one logic and the other is captured by the conditions under which a branch is declared closed; (d) such conditions depend only on the labelling algebra associated with each logic; and (e) classical and intuitionistic negations are characterized uniformly, by means of the same tree-expansion rules, and their difference is reduced to a difference in the labelling algebra used in closing a branch. In this first part we lay the theoretical foundations of our method. In the second part we shall continue our investigation of substructural logics and discuss the algorithmic aspects of our approach.     

A graph grammar-based formal validation of object-process diagrams

Two basic requirements from a system’s conceptual model are correctness and comprehensibility. Most modeling methodologies satisfy only one of these apparently contradicting requirements, usually comprehensibility, leaving aside problems of correctness and ambiguousness that are associated with expressiveness. Some formal modeling languages do exist, but in these languages a complete model of a complex system is fairly complicated to understand. Object-process methodology (OPM) is a holistic systems modeling methodology that combines the two major aspects of a system—structure and behavior—in one model, providing mechanisms to manage the complexity of the model using refinement-abstraction operations, which divide a complex system into many interconnected diagrams. Although the basic syntax and semantics of an OPM model are defined, they are incomplete and leave room for incorrect or ambiguous models. This work advances the formal definition of OPM by providing a graph grammar for creating and checking OPM diagrams. The grammar provides a validation methodology of the semantic and syntactic correctness of a single object-process diagram.     

Dependence of Hertzian fracture angle on Poissons ratio and indentation techniques

Sub-parallel concentric conic fractures can be produced consecutively in Perspex by liquid indentation. There is a linear relationshp between the conic angle, , of Hertzian fracture and the Poisson's ratio, , of the material. This angle is about 10 higher than the calculated path of the principal stress trajectory for a given . decreases with the increase of stress application rate. This dependence of is very marked in materials with high Poisson's ratios.     

A Multilevel Model of Safety Climate: Cross-Level Relationships Between Organization and Group-Level Climates.

Organizational climates have been investigated separately at organization and subunit levels. This article tests a multilevel model of safety climate, covering both levels of analysis. Results indicate that organization-level and group-level climates are globally aligned, and the effect of organization climate on safety behavior is fully mediated by group climate level. However, the data also revealed meaningful group-level variation in a single organization, attributable to supervisory discretion in implementing formal procedures associated with competing demands like safety versus productivity. Variables that limit supervisory discretion (i.e., organization climate strength and procedural formalization) reduce both between-groups climate variation and within-group variability (i.e., increased group climate strength), although effect sizes were smaller than those associated with cross-level climate relationships. Implications for climate theory are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Comparison between the apparent chemical diffusion coefficient evaluated from relaxation experiments by means of electrical conductivity changes and the corresponding theoretical value for a pure and doped p-type oxide

The chemical diffusion coefficient for a p-type oxide either pure or doped with an aliovalent impurity as evaluated from electrical conductivity changes in simulated relaxation experiments is compared with the corresponding theoretical values obtained on the basis of Fick's first law using a convenient model to represent the defect structure of the oxide. It is found that if the relaxation process is purely diffusion controlled, the experimental value of obtained ( ) is in rather good agreement with the theoretical value calculated by considering the diffusion of lattice defects rather than with that obtained by considering the diffusion of the prevailing electronic defects , even when the latter two values differ. This is shown to be the result of relatively small departures from a proportionality (for the pure oxide) or from a linear dependence (for a doped oxide) in the relationship between the deviation from stoichiometry and the concentration of the electron holes in restricted range of oxygen activity as used in relaxation experiments.     

Psychotherapy with Holocaust survivors.

Examines the specific tasks and goals of psychotherapy in treating survivors of massive psychic trauma, emphasizing the re-emergence of the internal representation of the relationship between self and other. Establishment of an empathic dyad between patient and therapist and reconstruction of external memory must occur before the therapist can successfully assume a more traditional interpretive role. Clinical examples illustrate the implications of therapeutic work with survivors and with children of survivors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Facets of work values: A structural analysis of work outcomes.

Attempted to analyze contents of work value items and to construct an explicit definition of the work values domain. A facet definition of work values is suggested that provides guidelines for selection items and the formulation of hypotheses about the structure of interrelationships among components of work values. Interview data were obtained from 2 samples of Israeli adults containing 489 Ss (median age 35 yrs) and 546 Ss (median age 38 yrs), respectively. Results of Guttman's smallest space analysis support the hypotheses. An empirical double-ordered conceptual system, a radex structure, was obtained that reflects the 2 facets of the definition: modality of outcome—material, social, and psychological—and type of outcome—performance relations (reward, resource). The fact that essentially the same structure was obtained in 2 independent samples lends substantial support to the definitional framework of work values suggested. (34 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determining production sequences for single-stage multifunctional machining systems based on the tradeoff between fixture cost, re-fixturing and tool replenishment

The main advantage of a Single-Stage Multifunctional machining System (SSMS) is its ability to combine many operations and processes, previously done on different machines in several stages, into a single stage. The flexibility and process variety these machining systems offer have ensured their widespread adoption in industry. As a result SSMSs frequently constitute the bottleneck of a manufacturing system and therefore control system throughput. Hence, it is imperative to use these resources efficiently. This study considers three possible costs and the tradeoffs between them that are pertinent to any job sequence: (i) the Tool Magazine Replenishment (TMR) cost; (ii) the Re-Fixturing (RF) cost; and (iii) the fixture cost. A job sequencing algorithm that minimizes these costs as well as the machine non-operational time, which stems from TMRs and RFs, is developed. The algorithm takes into account the tools and fixture requirements as well as the tool magazine capacity. The algorithm also recommends purchasing additional fixtures when economically justified. The algorithm is used to solve a job sequencing problem that occurs in a real industrial setting.     

Permeated Porous Silicon Suspended Membrane as Sub-ppm Benzene Sensor for Air Quality Monitoring

To realise advanced microsensors for a reliable monitoring of very low concentrations of pollutant species such as NO_x, SO₂, CO, O₃ and aromatic hydrocarbons, the use of porous silicon (PS) permeated with semiconducting oxides has been explored. To reduce the power consumption and to make feasible the device to operate in a fast pulsed temperature mode, a novel sensor architecture has been designed. The main feature of the device is represented by a permeated suspended macroporous Si membrane, few tens of microns thick. In this paper the porous silicon formation through a suspended silicon membrane and the morphological characterization of the PS layer are reported. Moreover, the performance of a C₆H₆ gas sensor based on the suspended macroporous Si membrane (30 m thick), permeated with the chemical precursor of Sn oxide is presented. The results have demonstrated the feasibility to realize a macroporous silicon suspended membrane with high specific surface area, efficient electrical insulation and negligible warpage. Furthermore, the permeation of the oxidized macroporous silicon membrane with SnO₂ has been proved to be a valuable approach to fabricate gas sensors suitable to detect aromatic hydrocarbons in a sub-ppm range.