Statistical methodologies for the control of dynamic remapping

Following an initial mapping of a problem onto a multiprocessor machine or computer network, system performance often deteriorates with time. In order to maintain high performance, it may be necessary to remap the problem. The decision to remap must take into account measurements of performance deterioration, the cost of remapping, and the estimated benefits achieved by remapping. We examine the tradeoff between the costs and the benefits of remapping two qualitatively different kinds of problems. One problem assumes that performance deteriorates gradually, the other assumes that performance deteriorates suddenly. We consider a variety of policies for governing when to remap. In order to evaluate these policies, statistical models of problem behaviors are developed. Simulation results are presented which compare simple policies with computationally expensive optimal decision policies; these results demonstrate that for each problem type, the proposed simple policies are effective and robust

Advanced information processing system: The Army fault tolerant architecture conceptual study. Volume 1: Army fault tolerant architecture overview

Digital computing systems needed for Army programs such as the Computer-Aided Low Altitude Helicopter Flight Program and the Armored Systems Modernization (ASM) vehicles may be characterized by high computational throughput and input/output bandwidth, hard real-time response, high reliability and availability, and maintainability, testability, and producibility requirements. In addition, such a system should be affordable to produce, procure, maintain, and upgrade. To address these needs, the Army Fault Tolerant Architecture (AFTA) is being designed and constructed under a three-year program comprised of a conceptual study, detailed design and fabrication, and demonstration and validation phases. Described here are the results of the conceptual study phase of the AFTA development. Given here is an introduction to the AFTA program, its objectives, and key elements of its technical approach. A format is designed for representing mission requirements in a manner suitable for first order AFTA sizing and analysis, followed by a discussion of the current state of mission requirements acquisition for the targeted Army missions. An overview is given of AFTA's architectural theory of operation

Penelope: The NBTI-aware processor

Transistors consist of lower number of atoms with every technology generation. Such atoms may be displaced due to the stress caused by high temperature, frequency and current, leading to failures. NBTI (negative bias temperature instability) is one of the most important sources of failure affecting transistors. NBTI degrades PMOS transistors whenever the voltage at the gate is negative (logic inputPeer ReviewedPostprint (published version

Five-Axis Machine Tool Condition Monitoring Using dSPACE Real-Time System

This paper presents the design, development and SIMULINK implementation of the lumped parameter model of C-axis drive from GEISS five-axis CNC machine tool. The simulated results compare well with the experimental data measured from the actual machine. Also the paper describes the steps for data acquisition using ControlDesk and hardware-in-the-loop implementation of the drive models in dSPACE real-time system. The main components of the HIL system are: the drive model simulation and input – output (I/O) modules for receiving the real controller outputs. The paper explains how the experimental data obtained from the data acquisition process using dSPACE real-time system can be used for the development of machine tool diagnosis and prognosis systems that facilitate the improvement of maintenance activities

Factors Associated with Success in PARE Testing Among RCMP Officers

The purpose of this integrated article dissertation was to examine the predictive factors for success in the RCMP’s Physical Abilities Requirement Evaluation (PARE) in a retrospective observational study of 13, 709 unique records and a divisional subset of 620 for study two and three. Study one assessed the relative predictive power of the pursuit and body control times, while including covariates of height, weight, age. Significant (p\u3c 0.05) and equally strong effects were for pursuit log odds (LO) of 2.95% CI [2.49, 3.11], and body control time LO of 2.80, 95% CI [2.51, 3.14] with a weak predictor , LO of 0.53, 95% CI [0.38, 0.72]. Not significant were height, weight, and sex with 99 % modeling accuracy. Study two compared sex and performance factors on six repeated PARE pursuit circuit laps for pacing for both divisional data (535 men, 85 women) and 61 age and BMI matched male/female pairs. Results divisional data: significant strong performance (pass/fail) effects F(1,616)=288.3, p\u3c .00, partial η2 = .32 but weak sex (male/female) effects F(1,616) = 27.2, p =.03, partial η2= .01, interaction was significant, F(1,616)=50.7, p\u3c .01, but weak, partial η2 = 0.014. Repeat laps were significant, F(3.7, 229)=195.1, p2=0.24; performance*laps interaction was significant F(3.7, 229)=4.5, p =.02, with weak effects, partial η2 = .007. Significant repeat lap contrasts were lap 1-2, strong effects and lap 2-3, lap 3-4, lap 4-5 weak effects, and not significant was lap 5-6. Results matched pairs data supported significant strong performance effects, F(1,118)=90.9, p2=.44 and weak sex effects, F(1,118)=13.5, p2=.10 not clinically significant. Significant repeat laps contrasts: laps 1-2, strong effect, lap 3-4 and lap 4-5, weak effect, lap 2-3 and lap 5-6 contrast was not significant. Men and women officers paced PARE repeat laps with slight ordinal interaction at lap three and six. The purpose of study three was to assess self-reported physical activity (PA) frequency and intensity as potential additional significant predictors of PARE success. PA frequency of 3.5 day/week, and intensity of 2.2 of 3.0, did not support additional predictors. There appears to be insufficient PA to affect a maximal test. Additional self-reported mode and dimensions of PA might increase PA predictability

Critical Market Crashes

This review is a partial synthesis of the book ``Why stock market crash'' (Princeton University Press, January 2003), which presents a general theory of financial crashes and of stock market instabilities that his co-workers and the author have developed over the past seven years. The study of the frequency distribution of drawdowns, or runs of successive losses shows that large financial crashes are ``outliers'': they form a class of their own as can be seen from their statistical signatures. If large financial crashes are ``outliers'', they are special and thus require a special explanation, a specific model, a theory of their own. In addition, their special properties may perhaps be used for their prediction. The main mechanisms leading to positive feedbacks, i.e., self-reinforcement, such as imitative behavior and herding between investors are reviewed with many references provided to the relevant literature outside the confine of Physics. Positive feedbacks provide the fuel for the development of speculative bubbles, preparing the instability for a major crash. We demonstrate several detailed mathematical models of speculative bubbles and crashes. The most important message is the discovery of robust and universal signatures of the approach to crashes. These precursory patterns have been documented for essentially all crashes on developed as well as emergent stock markets, on currency markets, on company stocks, and so on. The concept of an ``anti-bubble'' is also summarized, with two forward predictions on the Japanese stock market starting in 1999 and on the USA stock market still running. We conclude by presenting our view of the organization of financial markets.Comment: Latex 89 pages and 38 figures, in press in Physics Report

Advanced information processing system: The Army fault tolerant architecture conceptual study. Volume 2: Army fault tolerant architecture design and analysis

Described here is the Army Fault Tolerant Architecture (AFTA) hardware architecture and components and the operating system. The architectural and operational theory of the AFTA Fault Tolerant Data Bus is discussed. The test and maintenance strategy developed for use in fielded AFTA installations is presented. An approach to be used in reducing the probability of AFTA failure due to common mode faults is described. Analytical models for AFTA performance, reliability, availability, life cycle cost, weight, power, and volume are developed. An approach is presented for using VHSIC Hardware Description Language (VHDL) to describe and design AFTA's developmental hardware. A plan is described for verifying and validating key AFTA concepts during the Dem/Val phase. Analytical models and partial mission requirements are used to generate AFTA configurations for the TF/TA/NOE and Ground Vehicle missions

Deep Reinforcement Learning for Event-Triggered Control

Event-triggered control (ETC) methods can achieve high-performance control with a significantly lower number of samples compared to usual, time-triggered methods. These frameworks are often based on a mathematical model of the system and specific designs of controller and event trigger. In this paper, we show how deep reinforcement learning (DRL) algorithms can be leveraged to simultaneously learn control and communication behavior from scratch, and present a DRL approach that is particularly suitable for ETC. To our knowledge, this is the first work to apply DRL to ETC. We validate the approach on multiple control tasks and compare it to model-based event-triggering frameworks. In particular, we demonstrate that it can, other than many model-based ETC designs, be straightforwardly applied to nonlinear systems

Time dependent unavailability analysis to standby safety systems

"Prepared for Brookhaven National Laboratory."Includes bibliographical references (p. 280-284)Contract no. BNL-54668