Real-time Programming Research Articles

Energy‐Aware Scheduling with Uncertain Execution Time for Real‐Time Systems

Energy-saving is extraordinary important for real-time systems. Dynamic voltage scaling (DVS) is an important technique to reduce the energy consumption of processors that support voltage scaling. It has been exploited extensively in task scheduling. However, many approaches take simple treatments and some of them even neglect the large voltage transition overheads. Although some strategies consider the penalty, frequency switching produces extra large time overhead and deadline misses occur frequently. In our paper, we propose an energy efficient soft real-time dynamic program scheme by using quantitative switching overhead and communication penalty for multitask scheduling with uncertain execution time. The experiments show that our approaches significantly outperform existing solutions both on simple-core and multi-core systems in terms of energy-saving.

Neutron Flux Signal Acquisition from Plant Instrumentation Channel of Research Reactor for Reactivity Calculation

A design for instantaneous neutron flux signal acquisition system is being carried out for reactivity measurement of the nuclear research reactor. It is a computer-based digital data acquisition system that can perform continuous monitor and measurement of reactivity inserted into or removed from the research reactor. The acquisition system accomplishes with two major parts. The first part is an interfacing PCI based data acquisition card and the corresponding driver software intending to on-line acquisition of neutron flux signals from plant instrumentation channel. The second part incorporates the high-level Visual Basic real time program, indigenously developed for computation of reactivity by the solution of neutron point kinetic equations and other relevant functional modules like input file logging, reactivity calculation, graphics demonstration etc.

BRIEF ANALYSIS OF REAL-TIME DATA COMPUTER REGISTRATION, TRANSMISSION AND PROCESSING METHODS IN NUCLEAR PHYSICS

Structural and principal problems in the field of control equipment for nuclear physics development are examined, in particular, the influence of dead time on the spectrum data aggregation and methods of correcting this influence. The variants of the organization of spectrometric systems, their advantages and disadvantages, the possibility of using different digital interfaces and computer buses are analyzed, and some of existing spectrometric equipment implementations examples are reviewed. The result of the work is an analysis of existing approaches to the equipment for electronic spectrometry organization and development, as well as a recommendation based on the approaches and different technological solutions to achieve the best ratio of performance and versatility is given. The problems that may be encountered in the spectrometric equipment development process and the existing solutions are described. The workability of various operating systems and real-time programming modules to the organization of processing equipment is examined, also the impact on the development-related cost and laboriousness of the opted facilities for solving these problems is examined, and the optimal solutions are proposed.

Satisfaction and Experience With a Supervised Home-Based Real-Time Videoconferencing Telerehabilitation Exercise Program in People with Chronic Obstructive Pulmonary Disease (COPD).

Telerehabilitation, consisting of supervised home-based exercise training via real-time videoconferencing, is an alternative method to deliver pulmonary rehabilitation with potential to improve access. The aims were to determine the level of satisfaction and experience of an eight-week supervised home-based telerehabilitation exercise program using real-time videoconferencing in people with COPD. Quantitative measures were the Client Satisfaction Questionnaire-8 (CSQ-8) and a purpose-designed satisfaction survey. A qualitative component was conducted using semi-structured interviews. Nineteen participants (mean (SD) age 73 (8) years, forced expiratory volume in 1 second (FEV1) 60 (23) % predicted) showed a high level of satisfaction in the CSQ-8 score and 100% of participants reported a high level of satisfaction with the quality of exercise sessions delivered using real-time videoconferencing in participant satisfaction survey. Eleven participants undertook semi-structured interviews. Key themes in four areas relating to the telerehabilitation service emerged: positive virtual interaction through technology; health benefits; and satisfaction with the convenience and use of equipment. Participants were highly satisfied with the telerehabilitation exercise program delivered via videoconferencing.

A Research on Online Judge Technology Based on MOOC Platform

Programming courses in Chinese university MOOC(massive open online courses) platform use Online Judge as a real-time program automatic grading tool. One the one hand, the use of Online Judge increases the ability of programming, on the other hand it decreases the workload of teachers. So more and more programming courses are taught based on Online Judge. Although Online Judge has many advantages, we find some shortcomings during long-term use. This paper describes the technology of online judge, then analyses advantages and disadvantages. Considering these disadvantages, we put forward a method to make it more suitable for programming practice and test.

Análisis de la implementación software de un conformador de señales ultrasónicas para tiempo real

This paper studies the software implementation in an ultrasonic imaging system of Total Focusing Method. In order to accomplish real-time requirements parallel programming techniques have been used. Then, using GPGPU techniques, two different implementation alternatives are analysed, showing how proper planning of access to data improves the performance of the algorithm.

Wireless Real-Time Program Successfully Monitors Recovery after Major Abdominal Surgery

Wireless Real-Time Program Successfully Monitors Recovery after Major Abdominal Surgery

Evaluation of pseudoephedrine pharmacy sales before and after mandatory recording requirements in Western Australia: a case study

BackgroundA community pharmacy real-time electronic recording program, ProjectSTOP, enables Australian community pharmacists to verify pseudoephedrine requests. In Western Australia the program was available for voluntary use from April 2007 and became mandatory November 2010. This case study explores the effectiveness of the program by reviewing the total requests for pseudoephedrine products, and the proportion of requests which were classified as ‘denied sales’ before and after mandatory implementation. Seasonal and annual trends in these measures are also evaluated.MethodsProjectSTOP data recordings for Western Australia pharmacies between 1 December 2007 and 28 February 2014 were analysed. Data included a de-identified pharmacy number and date of each pseudoephedrine product request. The total number of requests and sale classification (allowed, denied, safety, or not recorded) were calculated for each month/pharmacy. The potential influence of mandatory reporting using ProjectSTOP was investigated using a Regression Discontinuity Design. Correlations between sales from the same pharmacy were taken into account by classifying the pharmacy number as a random effect. The main effects of year (continuous variable), and season (categorical variable) were also included in the model.ResultsThere was a small but steady decline in the total requests for pseudoephedrine per month per 100,000 population (per pharmacy) from the time of mandatory reporting. The number of denied sales showed a steady increase up until mandatory reporting, after which it showed a significant decline over time. Total sales were heavily influenced by season, as expected (highest in winter, least in summer). The seasonal pattern was less pronounced for denied sales, which were highest in winter and similar across other seasons. The pattern over time for safety sales was similar to that for denied sales, with a clear change occurring around the time of mandatory reporting.ConclusionResults indicate a decrease in pseudoephedrine product requests in Western Australia community pharmacies. Findings suggest ProjectSTOP has been successful in addressing suspicious sales and potential diversion however ongoing data review is recommended.

Real-time electricity pricing of a comprehensive demand response model in smart grids

This paper proposes a real-time interactional pricing scheme to maximize the social welfare of players in real-time demand response program in smart grids. Lagrangian relaxation–based dual decomposition is used to separate the social welfare optimization problem into a retailer's problem along with many consumers' subproblems, and the gradient projection method is adopted to solve them. First, the consumers' subproblems are solved to determine the optimal demand responses to the price announced by the retailer. To obtain the optimal demand response, a comprehensive mathematical function is developed on the basis of a combination of 5 costumer's utility functions reported in literature (ie, linear, potential, logarithmic, exponential, and hyperbolic). Afterward, the retailer calculates a real-time price in response to the consumers' reactions to maximize its profit. In terms of practical implementation, the consumers and the retailer interact with each other via a limited number of control messages exchanges to find the optimal solution at each hour. The proposed method is evaluated considering the various retailer's cost functions and the consumers' behaviors. Also, the results of elasticity sensitivity analysis are presented from the retailer and consumer viewpoints.

Distributed Intelligent MEMS

In recent years, distributed intelligent microelectromechanical systems (DiMEMSs) have appeared as a new form of distributed embedded systems. DiMEMSs contain thousands or millions of removable autonomous devices, which will collaborate with each other to achieve the final target of the whole system. Programming such systems is becoming an extremely difficult problem. The difficulty is due not only to their inherent nature of distributed collaboration, mobility, large scale, and limited resources of their devices (e.g., in terms of energy, memory, communication, and computation) but also to the requirements of real-time control and tolerance for uncertainties such as inaccurate actuation and unreliable communications. As a result, existing programming languages for traditional distributed and embedded systems are not suitable for DiMEMSs. In this article, we first introduce the origin and characteristics of DiMEMSs and then survey typical implementations of DiMEMSs and related research hotspots. Finally, we propose a real-time programming framework that can be used to design new real-time programming languages for DiMEMSs. The framework is composed of three layers: a real-time programming model layer, a compilation layer, and a runtime system layer. The design challenges and requirements of these layers are investigated. The framework is then discussed in further detail and suggestions for future research are given.

An isogeometric analysis approach for solving the Reynolds equation in lubricated piston dynamics

This paper discusses the approach of isogeometric analysis (IGA) for solving the Reynolds equation in lubricated piston dynamics. The simulation model consists of two parts: the differential-algebraic equations (DAE) in piston dynamics and the Reynolds equation for lubrication of piston-cylinder interface. Here, the transient positional states of piston governed by the DAE are calculated in Dymola while the friction forces together with lateral forces and their moments are computed by solving the Reynolds equation with the IGA approach in Matlab; two parts of computation are integrated through a real-time communication program. The results show that the efficiency is improved remarkably than the traditional Finite Element Method (FEM) when the IGA approach is adopted.

Programming Language Constructs Supporting Fault Tolerance

In order to render software viable for highly safety-critical applications, we describe how to incorporate fault tolerance mechanisms into the real-time programming language PEARL. Therefore, we present, classify, evaluate and illustrate known fault tolerance methods for software. We link them together with the requirements of the international standard IEC 61508-3 for functional safety. We contribute PEARL-2020 programming language constructs for fault tolerance methods that need to be implemented by operating systems, and code-snippets as well as libraries for those independent from runtime systems.

Parallelizing Industrial Hard Real-Time Applications for the parMERASA Multicore

The EC project parMERASA (Multicore Execution of Parallelized Hard Real-Time Applications Supporting Analyzability) investigated timing-analyzable parallel hard real-time applications running on a predictable multicore processor. A pattern-supported parallelization approach was developed to ease sequential to parallel program transformation based on parallel design patterns that are timing analyzable. The parallelization approach was applied to parallelize the following industrial hard real-time programs: 3D path planning and stereo navigation algorithms (Honeywell International s.r.o.), control algorithm for a dynamic compaction machine (BAUER Maschinen GmbH), and a diesel engine management system (DENSO AUTOMOTIVE Deutschland GmbH). This article focuses on the parallelization approach, experiences during parallelization with the applications, and quantitative results reached by simulation, by static WCET analysis with the OTAWA tool, and by measurement-based WCET analysis with the RapiTime tool.

OpenMP Fortran and C programs for solving the time-dependent Gross–Pitaevskii equation in an anisotropic trap

We present new version of previously published Fortran and C programs for solving the Gross-Pitaevskii equation for a Bose-Einstein condensate with contact interaction in one, two and three spatial dimensions in imaginary and real time, yielding both stationary and non-stationary solutions. To reduce the execution time on multicore processors, new versions of parallelized programs are developed using Open Multi-Processing (OpenMP) interface. The input in the previous versions of programs was the mathematical quantity nonlinearity for dimensionless form of Gross-Pitaevskii equation, whereas in the present programs the inputs are quantities of experimental interest, such as, number of atoms, scattering length, oscillator length for the trap, etc. New output files for some integrated one- and two-dimensional densities of experimental interest are given. We also present speedup test results for the new programs.

CyberEx Internet-Based Group Exercise for Rural Older Adults: A Pilot Study

The purpose of this study was to examine satisfaction with and outcomes of a real-time Internet-based group exercise program for older adults. Men and women age 50 and older (mean = 66.5) were recruited to participate in a 10-week distance group exercise program. Paired sample t-tests revealed that Sit-To-Stand (STS) repetitions increased significantly (p = .009), while Timed Up-and-Go(TUG) time decreased significantly (p = .000). Connectivity, visibility, and communication emerged as themes related to the use of technology; but overall, real-time Internet-based technology was shown to be an effective way to present group exercise programs for older adults in this rural setting.

Prescription drug monitoring in Australia: capacity and coverage issues.

ecent years have seen increases in prescription of Rpharmaceutical opioids and benzodiazepines, and in the associated harms. This presents challenges for clinicians and governments regarding appropriate monitoring and responses. Real-time prescription drug monitoring programs (RT-PDMPs) are being considered in Australia to enable detection of drug diversion (when drugs are transferred from a licit to an illicit channel of distribution or use), and inappropriate prescribing or dispensing. RT-PDMPs are supported by professional bodies, but challenges exist for policy makers in terms of capacity and coverage.

Teaching real-time programming using mobile robots

Teaching theoretical concepts of real-time systems may be a challenging task without real hardware support. This paper discusses the use of the LEGO MINDSTORMS NXT mobile robots for teaching real-time programming to bachelor’s students. The stable real-time control of a segway-like robot with a PID controller is used as case study to demonstrate the teaching methodology. Ada was used as real-time programming language. In general, very positive reviews were collected from the students after the course.

Integrating Automated Toll Discounts into a Real-Time Ridesharing Program

A pilot program in Austin, Texas, tested the practicality of integration of a real-time ridesharing application with a toll operator to process toll discounts for carpools. The toll discounts appeared on monthly toll transaction statements. The program lasted for almost a year on the 183A Toll Road and the US-290 Manor Expressway. Travelers used a smartphone application to track, record, and submit their trips for discounts. Two-person carpools that used the application received a 50% discount, and carpools of three or more people could travel toll free. The program was a partnership between the Central Texas Regional Mobility Authority, the local toll system operator, and a private ridesharing vendor. Back-office processes matched trip data from the smartphone application to transactions recorded by the toll systems. A total of 95 unique drivers were provided toll rebates for 2,213 trips during the 10.5-month period of the pilot program. During the pilot program, rebates were provided for most trips by two-person carpools. Individual driver behavior varied considerably. A select few drivers had a high number of carpool trips, whereas others took a sporadic trip or infrequent trips. Drivers took a median of seven trips during the pilot program. Future ridesharing programs should consider showing higher-dollar-value rebates that represent annual savings to incentivize ridesharing behavior. Timely feedback to users was found to be an important goal for success. In addition, program sponsors should provide positive customer service and engage users when problems that are not under their direct purview exist.

Performance evaluation of CMSIS-RTOS: benchmarks and comparison

The CMSIS-RTOS standard, recently published by ARM, defines a real-time operating system application programming interface (RTOS API) for lower-end microcontrollers. The benefits of such a standard include the improvement of portability among microcontroller applications, the incentive to the market of standardised middleware libraries, and the acceleration of the learning curve for RTOS-users. CMSIS-RTOS was designed for the ARM Cortex-M family of 32-bit RISC microcontrollers but its applicability encompasses the full range of lower-end microcontrollers. The target hardware platform of CMSIS-RTOS encompasses a different range than those where the POSIX standard is applicable. Compliance with the CMSIS-RTOS standard can be achieved by design, which is the case for new RTOSes, or by an adaptation layer on top of an existing RTOS. The performance evaluation conducted in this research covers both cases. The research question is: 'Does compliance with the CMSIS-RTOS standard impose a performance penalty?'. This is the first reported research to conduct a performance evaluation of CMSIS-RTOS; the results presented here indicate that compliance with the CMSIS-RTOS standard does not impose a performance penalty.

Устройство и архитектура операционной системы реального времени

Modern airliners such as Airbus A320, Boeing 787, and Russian MS-21 use so called Integrated Modular Avionics (IMA) architecture for airborne systems. This architecture is based on interconnection of devices and on-board computers by means of uniform real-time network. It allows significant reduction of cable usage, thus leading to reducing of takeoff weight of and airplane. IMA separates functions of collecting information (sensors), action (actuators), and avionics logic implemented by applied avionics software in on-board computers. International standard ARINC 653 defines constraints on the underlying real-time operation system and programming interfaces between operating system and associated applications. The standard regulates space and time partitioning of applied IMA-related tasks. Most existing operating systems with ARINC 653 support are commercial and proprietary software. In this paper, we present JetOS, an open source real-time operating system with complete support of ARINC 653 part 1 rev 3. JetOS originates from the open source project POK, created by French researchers. At that time POK was the only one open source OS with at least partial support for ARINC 653. Despite this, POK was not feasible for practical usage: POK failed to meet a number of fundamental requirements and was executable in emulator only. During JetOS development POK code was significantly redesigned. The paper discusses disadvantages of POK and shows how we solved those problems and what changes we have made in POK kernel and individual subsystems. In particular we fully rewrote real-time scheduler, network stack and memory management. Also we have added some new features to the OS. One of the most important features is system partitions. System partition is a specialized application with extended capabilities, such as access to hardware (network card, PCI controller etc.) Introduction of system partitions allowed us moving large subsystems out of the kernel and limiting the kernel to the minimal functionality: context switching, scheduling and message pass. In particular, we have moved network subsystem to system partition. This moving reduces kernel size and potentially reduces probability on having bug in kernel and simplifies verification process.