Architecture and Environment for Enabling Interactive Grids

Traditional use of grid computing allows a user to submit batch jobs in a grid environment. We believe, next generation grids will extend the application domain to include interactive graphical sessions. We term such grids Interactive Grids. In this paper, we describe some of the challenges involved in building Interactive Grids. These include fine grain access control, performance QoS guarantees, dynamic account management, scheduling, and user data management. We present the key architectural concepts in building Interactive Grids viz. hierarchical sessions, hierarchical admission control, hierarchical agents, classes of dynamic accounts, application profiling, user data management, scheduling for interactive sessions, persistent environment settings, and exporting remote desktop. We also describe IGENV, an environment for enabling interactive grids. IGENV consists of GISH –Grid Interactive Shell, Controlled Desktop, SAC –Session Admission Control module, GMMA –Grid Monitoring and Management Agents, and Policy Engine. We also present our testbed implementation for Interactive Grids using and extending Globus Toolkit 2.0 for the Grid middleware infrastructure, and VNC as the remote display technology.     

Physico-Chemical Studies on Microemulsion: Effect of Cosurfactant Chain Length on the Phase Behavior,Formation Dynamics,Structural Parameters and Viscosity of Water/(Polysorbate-20 + <Emphasis Type="Italic">n</Emphasis>-Alkanol)/<Emphasis Type="Italic">n</Emphasis>-Heptane Water-in-Oil Microemulsion

The pseudo-ternary water-in-oil microemulsion system, comprising water/polyoxyethylene sorbitan monolaurate (Polysorbate-20) + n-alkanol/n-heptane, have been studied by phase manifestation, method of dilution, viscosity and dynamic light scattering measurements. Polysorbate-20, in combination with equal mass of cosurfactants (of varying chain length, from n-butanol to n-octanol) were used in studying the systems in the temperature range 303–323 K. Appearance of turbidity was noted visually, which indicated the attainment of immiscibility or phase separation; a clear dependence of the different phases on cosurfactant chain length was noted. By employing the method of dilution, associated thermodynamic parameters for the formation of water-in-oil microemulsion droplets were derived. Different associated structural parameters were derived through further computation of the data derived from the method of dilution. Unusual behavior of Polysorbate-20, compared to the conventional ionic surfactants, was noted. Viscosity measurements, as carried out with different compositions and temperatures, revealed the temperature and water pool size dependency of the microemulsion systems. Viscosity data did not follow the same trend during heating and the cooling process, due to the condensation effect. This phenomenon was further confirmed by dynamic light scattering measurements.     

A Corrigendum to: “Sticky-ERfair: a task-processor affinity aware proportional fair scheduler”

This paper provides a corrigendum to resolve a couple of minor issues in the algorithm presented in Sarkar et al. (Real-Time Syst., 2011). The first issue relates to the postponement of execution of a task when its own ‘deadline of postponement’ have not been crossed. The second issue concerns the updation of certain scheduler data structures.     

Effect of Cold Rolling on as–ECAP Interstitial Free Steel

Ti-stabilized interstitial free steel subjected to eight passes, route B_C room temperature equal channel angular pressing (ECAP) additionally was cold rolled (CR) up to 95 pct thickness reduction. Electron back-scattering diffraction and transmission electron microscopy characterized microstructural refinement and microtexture evolution, whereas the mechanical properties were assessed by uniaxial tensile tests. After 95 pct CR, the average high-angle grain boundary spacing reduces to 0.14 μm, whereas the high-angle boundary fraction increases to ~81 pct. The ECAP negative simple shear texture components rotate by ~15 deg around the transverse direction toward the rolling direction for up to 50 pct CR, with typical rolling textures observed at 95 pct CR. The decrease in boundary spacing produces a ~500 MPa gain in 0.2 pct proof stress, a ~600 MPa increase in ultimate tensile strength (UTS), and a ~4 pct loss in total elongation after 95 pct CR. Similar rates of decrease in work hardening correspond to comparable rates of cross and/or multiple slip events irrespective of the processing regime and substructural refinement. The fracture mode of the tensile samples changes from ductile to brittle type between ECAP and 95 pct CR and is attributed to the reduced work hardening capacity of the latter. The modified Hall–Petch equation shows that the convergence of high-angle boundary spacing values with their low-angle counterparts results in an increased contribution via boundary strengthening to the 0.2 pct proof stress and UTS.     

Flagellar phenotypic plasticity in volvocalean algae correlates with Péclet number

Flagella-generated fluid stirring has been suggested to enhance nutrient uptake for sufficiently large micro-organisms, and to have played a role in evolutionary transitions to multicellularity. A corollary to this predicted size-dependent benefit is a propensity for phenotypic plasticity in the flow-generating mechanism to appear in large species under nutrient deprivation. We examined four species of volvocalean algae whose radii and flow speeds differ greatly, with Péclet numbers (Pe) separated by several orders of magnitude. Populations of unicellular Chlamydomonas reinhardtii and one- to eight-celled Gonium pectorale (Pe ∼ 0.1–1) and multicellular Volvox carteri and Volvox barberi (Pe ∼ 100) were grown in diluted and undiluted media. For C. reinhardtii and G. pectorale, decreasing the nutrient concentration resulted in smaller cells, but had no effect on flagellar length and propulsion force. In contrast, these conditions induced Volvox colonies to grow larger and increase their flagellar length, separating the somatic cells further. Detailed studies on V. carteri found that the opposing effects of increasing beating force and flagellar spacing balance, so the fluid speed across the colony surface remains unchanged between nutrient conditions. These results lend further support to the hypothesized link between the Péclet number, nutrient uptake and the evolution of biological complexity in the Volvocales.     

Fish Inspired Biomimetic Ionic Polymer-Metal Composite Pectoral Fins Using Labriform Propulsion

In this article, we analyze and design ionic polymer metal composite (IPMC) underwater propulsors inspired from swimming of labriform fishes. The structural model of the IPMC fin accounts for the electromechanical dynamics of the bean in water. A quasi steady blade element model that accounts for unsteady phenomena, such as added mass effects, dynamic stall, and cumulative Wagner effect is used to estimate the hydrodynamic performance. Dynamic characteristics of IPMC actuated flapping fins having the same size as the actual fins of three different fish species, Gomphosus varius, Scarus frenatus, and Sthethojulis trilineata, are analyzed using numerical simulations.     

Towards brain first-aid: a diagnostic device for conscious awareness

When the brain is damaged, evaluating an individual's level of awareness can be a major diagnostic challenge (Is he or she in there?). Existing tests typically rely on behavioral indicators, which are incorrect in as many as one out of every two cases. The current paper presents a diagnostic device that addresses this problem. The technology circumvents behavioral limitations through noninvasive brain wave measurements (electroencephalography, or EEG). Unlike traditional EEG, the device is designed for point-of-care use by incorporating a portable, user-friendly, and stable design. It uses a novel software algorithm that automates subject stimulation, data acquisition/analysis, and the reporting of results. The test provides indicators for five identifiable levels of neural processing: sensation, perception, attention, memory, and language. The results are provided as rapidly obtained diagnostic, reliability, validity, and prognostic scores. The device can be applied to a wide variety of patients across a host of different environments. The technology is designed to be wireless-enabled for remote monitoring and assessment capabilities. In essence, the device is developed to scan for conscious awareness in order to optimize subsequent patient care.     

Efficient microwave processing of oil–water emulsion cylinders with lateral and radial irradiations

A detailed theoretical analysis has been carried out to assess the role of lateral and radial irradiations on the microwave heating of 2D cylinders for both o/w and w/o emulsion samples. Lateral irradiation represents the sample incident at one direction with the source at infinity whereas radial irradiation represents the situation where the sample is incident with microwave radiations from the coaxial cylindrical cavity at infinity. For both of lateral and radial irradiations, the effective microwave incidence from the source is assumed to be identical. A preliminary analysis on the microwave heating of samples has been carried out via average power within a sample vs. sample diameter for emulsions with various values (volume fraction of the disperse phase). The samples with smaller diameter are found to have larger average power with radial irradiation for both o/w and w/o emulsion samples. The hot spot formation within a sample is found to be a strong function of lateral/radial irradiation for various emulsion compositions. The radial irradiation or conventional microwave heating with turntable rotation in ovens is not favorable especially for large w/o samples as the hot spot occurs at the center resulting in larger thermal gradient. The present work provides guideline on the heating policy based on either lateral or radial irradiation depending on the sample size and emulsion dielectric properties.     

Effect of Coiling Temperature on the Microstructure and Mechanical Properties of Hot-Rolled Ti–Nb Microalloyed Ultra High Strength Steel

A novel low carbon Ti–Nb microalloyed hot rolled steel with minimum yield strength of 700 MPa and good balance of stretch-flangeability and impact toughness has been developed by controlled thermo-mechanical processing following thin slab direct rolling route. In the present work, the effects of two coiling temperatures on the resulting microstructure, micro-texture and mechanical properties on this Ti–Nb microalloyed steel have been studied. It is observed that increase in coiling temperature from 520 to 580 °C significantly affects the mechanical properties. Higher dislocation density and increased precipitation along with slightly smaller grain size is observed for 580 °C coiling temperature resulting in about 50 MPa increase in yield and tensile strengths as compared to 520 °C coiling temperature.     

Sticky-ERfair: a task-processor affinity aware proportional fair scheduler

A drawback of current proportional fair schedulers is that they ignore task-to-processor mutual affinities, thereby causing frequent inter-processor task migrations and cache misses. This paper presents the Sticky-ERfair Scheduler, an Early-Release Fair (ERfair) scheduler that attempts to minimize task migrations and preemptions. Given any processor V _i , Sticky-ERfair allocates to it the most recently executed ready task that previously executed on V _i (thus restricting migrations and preemptions) in such a way that this allocation does not cause any ERfairness violations in the system at any time during the schedule length. Experimental results reveal that Sticky-ERfair can achieve upto over 40 times reduction both in the number of migrations and preemptions suffered with respect to Basic-ERfair (for a set of 25 to 100 tasks running on 2 to 10 processors) while simultaneously guaranteeing ERfairness at each time slot.