A Detailed Analysis of Contemporary ARM and x86 Architectures

RISC vs. CISC wars raged in the 1980s when chip area and processor design complexity were the primary constraints and desktops and servers exclusively dominated the computing landscape. Today, energy and power are the primary design constraints and the computing landscape is significantly different: growth in tablets and smartphones running ARM (a RISC ISA) is surpassing that of desktops and laptops running x86 (a CISC ISA). Further, the traditionally low-power ARM ISA is entering the high-performance server market, while the traditionally high-performance x86 ISA is entering the mobile low-power device market. Thus, the question of whether ISA plays an intrinsic role in performance or energy efficiency is becoming important, and we seek to answer this question through a detailed measurement based study on real hardware running real applications. We analyze measurements on the ARM Cortex-A8 and Cortex-A9 and Intel Atom and Sandybridge i7 microprocessors over workloads spanning mobile, desktop, and server computing. Our methodical investigation demonstrates the role of ISA in modern microprocessors? performance and energy efficiency. We find that ARM and x86 processors are simply engineering design points optimized for different levels of performance, and there is nothing fundamentally more energy efficient in one ISA class or the other. The ISA being RISC or CISC seems irrelevant

A Monte Carlo study of organ and effective doses of cone beam computed tomography (CBCT) scans in radiotherapy

Cone-beam CT (CBCT) scans utilized for image guided radiation therapy (IGRT) procedures have become an essential part of radiotherapy. The aim of this study was to assess organ and effective doses resulting from new CBCT scan protocols (head, thorax, and pelvis) released with a software upgrade of the kV on-board-imager (OBI) system. Influence of the scan parameters that were changed in the new protocols on the patient dose was also investigated. Organ and effective doses for protocols of the new software (V2.5) and a previous version (V1.6) were assessed using Monte Carlo (MC) simulations for the International Commission on Radiological Protection (ICRP) adult male and female reference computational phantoms. The number of projections and the mAs values were increased and the size of the scan field was extended in the new protocols. Influence of these changes on organ and effective doses of the scans was investigated. The OBI system was modelled in EGSnrc/BEAMnrc, and organ doses were estimated using EGSnrc/DOSXYZnrc. The MC model was benchmarked against experimental measurements. Organ doses resulting from the V2.5 protocols were higher than those of V1.6 for organs that were partially or fully inside the scans fields, and increased by (3 to 13)%, (10 to 77)%, and (13 to 21)% for the head, thorax, and pelvis protocols for both phantoms, respectively. As a result, effective doses rose by 14%, 17%, and 16% for the male phantom, and 13%, 18%, and 17% for the female phantom for the three scan protocols, respectively. The scan field extension for the V2.5 protocols contributed significantly in the dose increases, especially for organs that were partially irradiated such as the thyroid in head and thorax scans and colon in the pelvic scan. The contribution of the mAs values and projection numbers was minimal in the dose increases, up to 2.5%. The field size extension plays a major role in improving the treatment output by including more markers in the field of view to match between CBCT and CT images and hence setting up the patient precisely. Therefore, a trade-off between the risk and benefits of CBCT scans should be considered, and the dose increases should be monitored. Several recommendations have been made for optimization of the patient dose involved for IGRT procedures

On a swarm of Sergestid shrimps near Chennai

Swarm of Acetes sp. were observed during 20-30 April 2002 near shore along south Chennai coast.Aeru vallai or Mosquito net was operated to catch shrimps and overall catch comprises of Acetes species. The dominant species was Acetes indicus (90%) followed by A.japonicus (6%) and A. erythreaus

Constraint Centric Scheduling Guide

The advent of architectures with software-exposed resources (Spatial Architectures) has created a demand for universally applicable scheduling techniques. This paper describes our generalized spatial scheduling framework, formulated with Integer Linear Programming, and specifically accomplishes two goals. First, using the ?Simple? architecture, it illustrates how to use our open-source tool to create a customized scheduler and covers problem formulation with ILP and GAMS. Second, it summarizes results on the application to three real architectures (TRIPS,DySER,PLUG), demonstrating the technique?s practicality and competitiveness with existing schedulers

Studies on the Pyrolysis of Composite Solid Propellants leading to Ignition

Studies on the pyrolysis leading to ignition of polystyrene (PS)/ammonium perchlorate (AP), polyvinyl chloride (PVC)/AP and polyphenol formaldehyde (PPF)/AP  propellants revealed that the activation energy for the ignition strongly depends upon the binder. Double base propellants exhibit an empirical relationship between the ignition delay (~) and the oxidiser concentration; when the same equation is applied to composite solid propellants, the plot of In ~ vs In C (C=Concentration, %) yields a straight line with a knee corresponding to 65-70 per cent AP above which the dependence on ~ becomes less sensitive

Statistical Studies on Rainfall and Time-based Deviations in Precipitation Trends in Vaigai River Basin, TN State, India

15-23Food shortage and water shortage remains the most critical issues throughout the world. Understanding the variability in rainfall will help to make predictions about the rainfall patterns as well as addressing the issues of food-water-energy nexus. Herein, a trend analysis of rainfall was carried out in selected seven rainfall stations of Vaigai river basin in Tamil Nadu state, India. Statistical trend analysis was carried out, to observe the trend pattern for the period from 1959 to 2016. To determine the trend of rainfall, non-parametric Mann-Kendall test and Spearman Rho tests were used. This investigation provides insights about precipitation trends during annual, post-monsoon, pre-monsoon periods. These findings will provide clues for developing efficient water management systems using different simulation techniques and artificial intelligence approaches

Changes in the Calorimetric Value and Ignition Temperature of Composite Solid Propellants During Ageing-A Note

Calorimetric value and ignition temperature of carboxy terminated polybutadiene/ammonium perchlorate propellant decrease during accelerated ageing. The behaviour has been explained on account of binder loss and condensed phase reactions in the propellant matrix