Deadlock-free connection-based adaptive routing with dynamic virtual circuits

Virtual circuits (VCs) can reduce routing overheads with irregular topologies and provide support for a mix of quality of service (QoS) requirements. Information about network loads and traffic patterns may be used during circuit establishment to utilize network resources more efficiently than is practical with packet routing. Most VC schemes are static—each established VC remains unchanged until the connection is no longer needed. In contrast, we propose the dynamic virtual circuit (DVC) mechanism, which enables existing circuits to be quickly torn down in order to free up resources needed for other circuits or to re-establish circuits along routes that are better suited for current network conditions. We propose a deadlock avoidance technique, based on unconstrained routing of DVCs combined with a deadlock-free virtual network. We present a correctness proof for the scheme, describe key aspects of its implementation, and present performance evaluation results that explore its potential benefits.     

Is there an endogeneity problem between health and apartment value? Gender differences and the impact of obesity on property self-evaluation

Journal of Housing and the Built Environment - Background Numerous studies have compared self evaluation and market values of apartments by employing hedonic regressions. Most of these studies...     

Modeling the Aeration Efficiency of a Passively Aerated Vertical-Flow Biological Filter

A model aimed at calculating the aeration efficiency of a passively aerated biological vertical bed unit is presented. The model allows the calculation of the mass of air that would flow via convection into the vertical bed, therefore enabling the prediction of the maximal capacity of the bed as an aerobic biological reactor. Aeration efficiency, defined as the volume of air that would enter the bottom of the bed as a function of the volume of water that is drained from it, is predicted in the model as a function of the mean particle size of the gravel media, and the diameter and number of the aeration tubes installed. The model was calibrated in the laboratory and verified using results from a pilot scale vertical bed treating secondary municipal wastewater effluents. The principal model equation is: EPAVB = NPDp4/(NPDp4+0.285pDr22), where EPAFB=efficiency of the passive air pump (—); NP=number of aeration pipes (—); Dp=aeration pipes’ diameter (m); p=medium porosity (—); and Dr=vertical bed diameter (m).     

Nanoimprint Lithography for Functional Three‐Dimensional Patterns

Nanoimprint lithography (NIL) is viewed as an alternative nanopatterning technique to traditional photolithography, allowing micrometer‐scale and sub‐hundred‐nanometer resolution as well as three‐dimensional structure fabrication. In this Research News article we highlight current activities towards the use of NIL in patterning active or functional materials, and the application of NIL in patterning materials that present both chemistry and structure/topo­graphy in the patterned structures, which provide scaffolds for subsequent manipulation. We discuss and give examples of the various materials and chemistries that have been used to create functional patterns and their implication in various fields as electronic and magnetic devices, optically relevant structures, biologically important surfaces, and 3D particles.     

Arylmercury Compounds. Part VI. Asymmetric Diarylmercury Compounds

Asymmetric diarylmercury compounds were produced together with symmetric products via a symmetrization process. The asymmetric products could not be isolated from the reaction mixture and their existence was indicated through different analyses (mp, IR, PMR, mass spectra, elemental analysis and DTA). The asymmetric products were shown to be unstable and to disproportionate into two symmetric compounds at elevated temperatures, and in organic solvents even at room temperature.     

Interlaminar Stress Distribution Within an Adhesive Layer in the Nonlinear Range

The solution for interlaminar stress distribution in an adhesive layer within a bonded structure is highly complex due to the predominantly inelastic nature of the polymeric adhesive. The present study attacks this problem using a nonlinear finite-element method and an empirical effective-stress-strain relationship derived experimentally for a typical epoxy adhesive loaded at a constant strain rate. The stress distribution in the critical zone of the interlaminar layer of a symmetric doubler model is presented.