A new generation of soil-geosynthetic interaction experimentation

A new device was developed to comprehensively assess the interaction between soil and reinforcement as well as the interaction between neighboring reinforcement layers in a reinforced soil mass, under both working and ultimate interface shear stress conditions. An understanding of these two interactions is required to assess the mechanical behavior of a geosynthetic-reinforced soil mass considering varying vertical reinforcement spacings. Specifically, the new device allows direct visualization of the kinematic response of soil particles adjacent to the geosynthetic reinforcement layers, which facilitates evaluation of the soil displacement field via digital image analysis. Evaluation of the soil displacement field allows quantification of the extent of the shear influence zone around a tensioned reinforcement layer. Ultimately, the device facilitates investigating the load transfer mechanisms that occur not only at the soil-reinforcement interface, but also at distances farther from the interface, thereby providing additional insight into the effect of vertical reinforcement spacing on a reinforced soil mass. Finally, the device allows monitoring of dilatancy within the reinforced soil mass upon shear stress generation at the interface between soil and reinforcement. Overall, the device was found to provide the measurements needed to adequately predict the strains developing both in reinforcement layers tensioned by direct application of external loads as well as in reinforcement layers tensioned by the shear transfer induced by adjacent geosynthetic reinforcements. Ultimately, the proposed experimentation technique allows generation of data required to evaluate the load transfer mechanisms amongst soil and reinforcement layers in reinforced soil structures. The strain magnitude in the neighboring reinforcements was found to exceed a magnitude of 10% of the strain magnitude obtained in the active reinforcement. The zone of shear stress transfer from the soil-reinforcement interface was found to exceed 0.2 m on each side of the active reinforcement.     

Evo-devo of Child Growth: The Role of Weaning in the Transition from Infancy to Childhood

Homo sapiens are unique in having a life history phase of childhood, which follows infancy, as defined by breastfeeding. This review uses evolutionary life history theory in understanding child growth in a broad evolutionary perspective, using the data and theory of evolutionary predictive adaptive growth-related strategies for transition from infancy to childhood. We have previously shown that a delayed infancy–childhood transition has a lifelong impact on stature. Feeding practices during infancy are fundamental elements of nutrition as they program for future growth and body composition. A relationship between the duration of breastfeeding and the nature of weaning has been suggested as a possible cause for later obesity and growth patterns. This review highlights the role that breast milk feeding and variations in the weaning age have on transition to childhood, growth, and body composition.     

A Generic Integrated Line Detection Algorithm and Its Object–Process Specification

A generic integrated line detection algorithm (GILDA) is presented and demonstrated. GILDA is based on the generic graphics recognition approach, which abstracts the graphics recognition as a stepwise recovery of the multiple components of the graphic objects and is specified by the object–process methodology. We define 12 classes of lines which appear in engineering drawings and use them to construct a class inheritance hierarchy. The hierarchy highly abstracts the line features that are relevant to the line detection process. Based on the “Hypothesis and Test” paradigm, lines are detected by a stepwise extension to both ends of a selected first key component. In each extension cycle, one new component which best meets the current line's shape and style constraints is appended to the line. Different line classes are detected by controlling the line attribute values. As we show in the experiments, the algorithm demonstrates high performance on clear synthetic drawings as well as on noisy, complex, real-world drawings.     

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)