The effect of real workloads and stochastic workloads on the performance of allocation and scheduling algorithms in 2D mesh multicomputers

The performance of the existing non-contiguous processor allocation strategies has been traditionally carried out by means of simulation based on a stochastic workload model to generate a stream of incoming jobs. To validate the performance of the existing algorithms, there has been a need to evaluate the algorithms' performance based on a real workload trace. In this paper, we evaluate the performance of several well-known processor allocation and job scheduling strategies based on a real workload trace and compare the results against those obtained from using a stochastic workload. Our results reveal that the conclusions reached on the relative performance merits of the allocation strategies when a real workload trace is used are in general compatible with those obtained when a stochastic workload is used

Equivariant cohomology over Lie groupoids and Lie-Rinehart algebras

Using the language and terminology of relative homological algebra, in particular that of derived functors, we introduce equivariant cohomology over a general Lie-Rinehart algebra and equivariant de Rham cohomology over a locally trivial Lie groupoid in terms of suitably defined monads (also known as triples) and the associated standard constructions. This extends a characterization of equivariant de Rham cohomology in terms of derived functors developed earlier for the special case where the Lie groupoid is an ordinary Lie group, viewed as a Lie groupoid with a single object; in that theory over a Lie group, the ordinary Bott-Dupont-Shulman-Stasheff complex arises as an a posteriori object. We prove that, given a locally trivial Lie groupoid G and a smooth G-manifold f over the space B of objects of G, the resulting G-equivariant de Rham theory of f boils down to the ordinary equivariant de Rham theory of a vertex manifold relative to the corresponding vertex group, for any vertex in the space B of objects of G; this implies that the equivariant de Rham cohomology introduced here coincides with the stack de Rham cohomology of the associated transformation groupoid whence this stack de Rham cohomology can be characterized as a relative derived functor. We introduce a notion of cone on a Lie-Rinehart algebra and in particular that of cone on a Lie algebroid. This cone is an indispensable tool for the description of the requisite monads.Comment: 47 page

Adsorption of Line Segments on a Square Lattice

We study the deposition of line segments on a two-dimensional square lattice. The estimates for the coverage at jamming obtained by Monte-Carlo simulations and by $7^{th}$-order time-series expansion are successfully compared. The non-trivial limit of adsorption of infinitely long segments is studied, and the lattice coverage is consistently obtained using these two approaches.Comment: 19 pages in Latex+5 postscript files sent upon request ; PTB93_

Spin Glass Ordering in Diluted Magnetic Semiconductors: a Monte Carlo Study

We study the temperature-dilution phase diagram of a site-diluted Heisenberg antiferromagnet on a fcc lattice, with and without the Dzyaloshinskii-Moriya anisotropic term, fixed to realistic microscopic parameters for $IIB_{1-x} Mn_x Te$ (IIB=Cd, Hg, Zn). We show that the dipolar Dzyaloshinskii-Moriya anisotropy induces a finite-temperature phase transition to a spin glass phase, at dilutions larger than 80%. The resulting probability distribution of the order parameter P(q) is similar to the one found in the cubic lattice Edwards-Anderson Ising model. The critical exponents undergo large finite size corrections, but tend to values similar to the ones of the Edwards-Anderson-Ising model.Comment: 4 pages plus 3 postscript figure

A computational framework for modelling micro-scale fluids in the presence of surface tension

Immunisation, pioneered by Edward Jenner (1749-1823), has saved millions of lives and has helped the human race survive several disease pandemics. Today, the immunisation industry conducts vast amounts of research, not only developing new vaccinations, but also new methods of diagnosis. Currently, blood samples are taken manually using a syringe, loaded into a centrifuge and spun for several hours to separate out the different parts of the blood sample. These parts can then be tested manually for a range of ailments. In some areas of the world, access to such a device is unavailable and even if it was, this can be a long, energy intensive and costly process. Hence, new faster methods involving the use of microchips and surface acoustic waves and are an inviting possibility. Utilising the field of fluid dynamics, notably the work of Newton, Euler, Cauchy, Navier and Stokes, combined with modern computational methods allows for an engineering perspective to be taken on this problem. This thesis combines many novel contributions to create a computational modelling framework to model external excitation of axisymmetric micro-scale fluid droplets. In the present work fluid motion is governed by an axisymmetric form of the Navier-Stokes equations, with focus on incompressible Newtonian fluids, and this is presented in full. At the micro-scale, surface tension is the most dominant force, hence additional contributions are derived and included due to surface tension and contact line forces. Additionally, to reduce spurious oscillations within the pressure field, the pressure Laplacian stabilisation (PLS) technique is implemented. A derivation of the technique as well as an investigation into the effect of the stabilisation parameter is presented. The kinematics of the system are of great importance. At the micro-scale, tracking of the surface of the fluid is highly desirable and most advantageous, and the choice of kinematic description must reflect this. Unlike more traditional computational methods adopting an Eulerian description or a Lagrangian description of the governing equations, the presented computational framework makes use of the Arbitrary Lagrangian Eulerian (ALE) description. The ALE formulation avoids many of the drawbacks of traditional methods whilst allowing for accurate tracking of the fluid surface and minimising the requirement for frequent remeshing. Taking the current, deformed, configuration as the reference configuration in an Updated Lagrangian (UL) manner, combines into a kinematic description termed the Updated Arbitrary Lagrangian Eulerian (UALE) formulation. The physics underlying this formulation are presented in detail within this thesis. Several problems, examining a range of droplet volume, contact angle and experimental configuration are presented to validate the computational framework against analytical solutions. Of the various problems examined, all show a very good correlation to analytical solutions. Differences, if any, are attributed to the density of the mesh, which is shown to alter the amplitude but not the frequency of oscillation, or over-simplification made in the analytical solutions. Lastly, a new hypothesis is tested which until recently was extremely difficult to verify. The current hypothesis in the literature proposes that upon reaching the fluid-solid inter- face, surface acoustic waves propagate through the fluid causing motion. Conversely, the new hypothesis proposes that upon reaching the fluid-solid interface, surface acoustic waves propagate capillary waves up the surface of the droplet, changing the apparent wetting angle and inducing motion. This is implemented by changing the contact angle in time to simulate the action of surface acoustic waves and the resulting analysis recorded the occurrence of jetting thereby confirming the hypothesis. Further testing can be conducted and this technology utilised in the development of new disease diagnosis devices. The computational framework has been very successful in modelling a range of micro-scale problems. Further development of this framework will allow for a greater understanding of the effect of surface acoustic waves on a fluid droplet. In turn, this will allow for the improved design of surface acoustic wave devices

Information and support from dietary consultation for mothers of children with food allergies

BackgroundProfessional dietetic input is essential to ensure that children with diagnosed food allergies have an individualized avoidance plan and nutritionally adequate diet. However, it is not clear what dietary information and support parents require.ObjectiveTo explore what information and support parents of children with food allergies require from a dietary consultation.MethodsFocus groups were conducted with 17 mothers who attend an allergy center for dietary advice for their food allergic child. A number of issues around food allergy dietary advice needs were explored and analyzed using thematic analysis.ResultsSix themes were identified. The mothers described how they sought to protect their child from harm, to maintain normality for their child, and to promote child independence. They described needing to become an expert in their child's food allergy and fight their corner when needed. The dietitian supported their needs by ensuring their child's diet was safe and nutritionally adequate and giving information and support to help them provide a normal life for their child. Dietitians also taught mothers about food allergy and provided advocacy and emotional support.ConclusionMothers of children with food allergies want to understand how to provide a nutritionally adequate, allergen-safe diet while maintaining a normal life. Hence, mothers value a range of support from dietitians, including monitoring their child's health and providing information, practical advice and support, and emotional support

Rooting out ultraweak photon emission a-mung bean sprouts

It is well known that life has evolved to use and generate light, for instance, photosynthesis, vision and bioluminescence. What is less well known is that during normal metabolism, it can generate 1–100 photons s−1 cm–2 known as ultra-weak photon emission (UPE), biophoton emission or biological autoluminescence. The highest generation of these metabolic photons seem to occur during oxidative stress due to the generation and decay of reactive oxygen species (ROS), and their interaction with other components of the cell. To study this further, we have configured a sensitive detection system to study photon emission in germinating mung beans. Here we investigated growing mung beans over 7 days at a constant temperature of 21 ± 1 °C in a light tight box, using dual top and bottom opposing photomultiplier tubes. Over this time period we showed that in total, mung beans grown from seeds generated an average of 5 ± 1 counts s−1 above background. As the new bean stems grew, they showed a gradual linear increase in emission of up to 30 ± 1 counts s−1, in agreement with previous literature. In addition to this “steady-state” emission we also observe delayed luminescence and drought-stress response emission previously observed in other species. Finally, we also observe episodic increased emission events of between 2 and 15 counts s−1 for durations of around 3 h detected underneath the sample, and assign these to the growing of secondary roots. We then induce secondary root formation using aqueous solutions of growth hormones hydrogen peroxide (H2O2, 167 µM) or 3-indole acetic acid (IAA, 0.5 µM) for watering. Both hormones show prolonged increase in emission above steady-state, over days 3–5 with at least 3 times the number of secondary roots formed compared with water alone. We also observed a significant peak increase in photon emission (474 and 1738 cps vs. 28 and 55 cps for water alone) for the H2O2 which we attribute to direct ROS reaction emission as confirmed by measurement on dead plants. Altogether we have expanded upon and demonstrated an instrument and biological system for reliably producing and measuring intrinsic metabolic photons, first observed 100 years ago by Alexander Gurwitsch

Geopolímeros de metakaolin basados en potasio: papel de la relación K/Al y del curado en agua o con vapor a diferentes temperaturas

K-based geopolymer binder was prepared by reacting metakaolin with alkaline solutions having different potassium contents and by water curing at room temperature and 80 °C as well as steam curing at 150 and 180 °C. The phase formation, microstructure and Al and Si nearest neighbor environments were studied using XRD, TEM and 27Al and 29Si MAS NMR spectroscopy, respectively. The results revealed that amorphous alumino-silicates were predominant in geopolymer prepared by curing up to 28 days at room temperature or at 80 °C. The amorphous alumino-silicates persisted after hydrothermal treatment at 150 °C/48 hrs and even at 180 °C/30 hrs. However, the samples cured hydrothermally at 180 °C/48 hrs revealed formation of crystalline potassium aluminum silicate and chabazite phases. The Al nearest neighbor environments was not significantly affected by increasing the K/Al ratio up to 1.55 or by the curing temperatures. On the other hand, the geopolymer reaction appears to have increased when cured at 80 °C or steam cured at 150° and 180 °C and crystalline aluminosilicates resulted when the geopolymer sample was hydrothermally treated at 180 °C/48 hrs.Se prepararon geopolímeros por reacción de metacaolín con disoluciones alcalinas con diferentes contenidos de potasio. Se realizó un curado con agua a temperatura ambiente y a 80 °C, y con vapor de agua a 150 y 180 °C. La formación de las diferentes fases así como la microestructura y entornos del Al y Si se estudiaron mediante DRX, TEM y espectroscopia de RMN MAS de 27Al y 29Si. Los aluminosilicatos amorfos fueron predominantes en aquellos geopolímeros sometidos a curado de hasta 28 días a temperatura ambiente o a 80 °C. Los aluminosilicatos amorfos persistieron tras el tratamiento hidrotermal a 150 °C/48 horas e incluso a 180 °C/30 h. Sin embargo, las muestras curadas hidrotermalmente a 180 °C/48 h revelaron la formación de fases cristalinas de silicatos de aluminio y potasio, así como de chabazita. Los entornos de Al no resultaron afectados significativamente por el aumento de la relación K/Al de hasta 1.55, ni por las temperaturas de curado. Por otro lado, la reacción de geopolimerización aumentó cuando el curado se realizó a 80 °C o con curado a vapor a 150 y 180 °C

Superhard Phases of Simple Substances and Binary Compounds of the B-C-N-O System: from Diamond to the Latest Results (a Review)

The basic known and hypothetic one- and two-element phases of the B-C-N-O system (both superhard phases having diamond and boron structures and precursors to synthesize them) are described. The attention has been given to the structure, basic mechanical properties, and methods to identify and characterize the materials. For some phases that have been recently described in the literature the synthesis conditions at high pressures and temperatures are indicated.Comment: Review on superhard B-C-N-O phase

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma.

Sentinel-lymph-node biopsy is associated with increased melanoma-specific survival (i.e., survival until death from melanoma) among patients with node-positive intermediate-thickness melanomas (1.2 to 3.5 mm). The value of completion lymph-node dissection for patients with sentinel-node metastases is not clear. In an international trial, we randomly assigned patients with sentinel-node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph-node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma-specific survival. Secondary end points included disease-free survival and the cumulative rate of nonsentinel-node metastasis. Immediate completion lymph-node dissection was not associated with increased melanoma-specific survival among 1934 patients with data that could be evaluated in an intention-to-treat analysis or among 1755 patients in the per-protocol analysis. In the per-protocol analysis, the mean (±SE) 3-year rate of melanoma-specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log-rank test) at a median follow-up of 43 months. The rate of disease-free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log-rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log-rank test); these results must be interpreted with caution. Nonsentinel-node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group. Immediate completion lymph-node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma-specific survival among patients with melanoma and sentinel-node metastases. (Funded by the National Cancer Institute and others; MSLT-II ClinicalTrials.gov number, NCT00297895 .)