scholarly journals Real-Time Linux Analysis Using Low-Impact Tracer

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
François Rajotte ◽  
Michel R. Dagenais
Keyword(s):  
Real Time ◽  
Timing Constraints ◽  
Analysis Framework ◽  
Minimal Impact ◽  
Low Level ◽  
Potential Problems ◽  
Interactive Nature ◽  
Real Time Application

Debugging real-time software presents an inherent challenge because of the nature of real-time itself. Traditional debuggers use breakpoints to stop the execution of a program and allow the inspection of its status. The interactive nature of a debugger is incompatible with the strict timing constraints of a real-time application. In order to observe the execution of a real-time application, it is therefore necessary to use a low-impact instrumentation solution. Tracing allows the collection of low-level events with minimal impact on the traced application. These low-level events can be difficult to use without appropriate tools. We propose an analysis framework to model real-time tasks from tracing data recovered using the LTTng tracer. We show that this information can be used to populate views and help developers discover interesting patterns and potential problems.

scholarly journals A RED modified weighted moving average for soft real-time application

2014 ◽  
Vol 24 (3) ◽  
pp. 697-707 ◽  
Author(s):  
Joanna Domanśka ◽  
Adam Domański ◽  
Dariusz R. Augustyn ◽  
Jerzy Klamka
Keyword(s):  
Real Time ◽  
Optimization Problem ◽  
Optimality Criterion ◽  
Task Force ◽  
Moving Average ◽  
Timing Constraints ◽  
Real Time Traffic ◽  
Real Time Application ◽  
Weighted Moving Average

Abstract The popularity of TCP/IP has resulted in an increase in usage of best-effort networks for real-time communication. Much effort has been spent to ensure quality of service for soft real-time traffic over IP networks. The Internet Engineering Task Force has proposed some architecture components, such as Active Queue Management (AQM). The paper investigates the influence of the weighted moving average on packet waiting time reduction for an AQM mechanism: the RED algorithm. The proposed method for computing the average queue length is based on a difference equation (a recursive equation). Depending on a particular optimality criterion, proper parameters of the modified weighted moving average function can be chosen. This change will allow reducing the number of violations of timing constraints and better use of this mechanism for soft real-time transmissions. The optimization problem is solved through simulations performed in OMNeT++ and later verified experimentally on a Linux implementation

scholarly journals Evaluation of Optimal Vibrotactile Feedback for Force-Controlled Upper Limb Myoelectric Prostheses

Sensors ◽  
2019 ◽  
Vol 19 (23) ◽  
pp. 5209 ◽  
Author(s):  
Andrea Gonzalez-Rodriguez ◽  
Jose L. Ramon ◽  
Vicente Morell ◽  
Gabriel J. Garcia ◽  
Jorge Pomares ◽  
...  
Keyword(s):  
Real Time ◽  
Upper Limb ◽  
Closed Loop ◽  
Fine Tuning ◽  
Vibrotactile Feedback ◽  
Loop Control ◽  
Myoelectric Prostheses ◽  
Amplitude Level ◽  
Real Time Application ◽  
Selection Of

The main goal of this study is to evaluate how to optimally select the best vibrotactile pattern to be used in a closed loop control of upper limb myoelectric prostheses as a feedback of the exerted force. To that end, we assessed both the selection of actuation patterns and the effects of the selection of frequency and amplitude parameters to discriminate between different feedback levels. A single vibrotactile actuator has been used to deliver the vibrations to subjects participating in the experiments. The results show no difference between pattern shapes in terms of feedback perception. Similarly, changes in amplitude level do not reflect significant improvement compared to changes in frequency. However, decreasing the number of feedback levels increases the accuracy of feedback perception and subject-specific variations are high for particular participants, showing that a fine-tuning of the parameters is necessary in a real-time application to upper limb prosthetics. In future works, the effects of training, location, and number of actuators will be assessed. This optimized selection will be tested in a real-time proportional myocontrol of a prosthetic hand.

scholarly journals Research on Real-time Application of Ubiquitous Power Internet of Things Information Based on Smart Sensor Technology

2021 ◽  
Vol 714 (4) ◽  
pp. 042046
Author(s):  
Jiangping Nan ◽  
Yajuan Jia ◽  
Xuezhen Dai ◽  
Yinglu Liu ◽  
Xiaowen Ren ◽  
...  
Keyword(s):  
Internet Of Things ◽  
Real Time ◽  
Sensor Technology ◽  
Smart Sensor ◽  
Real Time Application

scholarly journals Feedback Relevance Spaces: Interactional Constraints on Processing Contexts in Dynamic Syntax

2021 ◽  
Author(s):  
Christine Howes ◽  
Arash Eshghi
Keyword(s):  
Semantic Processing ◽  
Corpus Study ◽  
British English ◽  
Low Level ◽  
Interactive Nature ◽  
Integrated Or ◽  
Dynamic Syntax ◽  
Do So

AbstractFeedback such as backchannels and clarification requests often occurs subsententially, demonstrating the incremental nature of grounding in dialogue. However, although such feedback can occur at any point within an utterance, it typically does not do so, tending to occur at Feedback Relevance Spaces (FRSs). We present a corpus study of acknowledgements and clarification requests in British English, and describe how our low-level, semantic processing model in Dynamic Syntax accounts for this feedback. The model trivially accounts for the 85% of cases where feedback occurs at FRSs, but we also describe how it can be integrated or interpreted at non-FRSs using the predictive, incremental and interactive nature of the formalism. This model shows how feedback serves to continually realign processing contexts and thus manage the characteristic divergence and convergence that is key to moving dialogue forward.

The logical design of a digital computer for a large-scale real-time application

1956 ◽  
Author(s):  
M. M. Astrahan ◽  
B. Housman ◽  
J. F. Jacobs ◽  
R. P. Mayer ◽  
W. H. Thomas
Keyword(s):  
Real Time ◽  
Digital Computer ◽  
Large Scale ◽  
Logical Design ◽  
Real Time Application

scholarly journals Network Calculus-Based Latency for Time-Triggered Traffic under Flexible Window-Overlapping Scheduling (FWOS) in a Time-Sensitive Network (TSN)

2021 ◽  
Vol 11 (9) ◽  
pp. 3896
Author(s):  
Khaled M. Shalghum ◽  
Nor Kamariah Noordin ◽  
Aduwati Sali ◽  
Fazirulhisyam Hashim
Keyword(s):  
Real Time ◽  
Connected Vehicles ◽  
Network Calculus ◽  
Timing Constraints ◽  
Traffic Scheduling ◽  
Worst Case ◽  
Continuous Increase ◽  
Scheduled Traffic ◽  
Support Time ◽  
New Framework

Deterministic latency is an urgent demand to pursue the continuous increase in intelligence in several real-time applications, such as connected vehicles and automation industries. A time-sensitive network (TSN) is a new framework introduced to serve these applications. Several functions are defined in the TSN standard to support time-triggered (TT) requirements, such as IEEE 802.1Qbv and IEEE 802.1Qbu for traffic scheduling and preemption mechanisms, respectively. However, implementing strict timing constraints to support scheduled traffic can miss the needs of unscheduled real-time flows. Accordingly, more relaxed scheduling algorithms are required. In this paper, we introduce the flexible window-overlapping scheduling (FWOS) algorithm that optimizes the overlapping among TT windows by three different metrics: the priority of overlapping, the position of overlapping, and the overlapping ratio (OR). An analytical model for the worst-case end-to-end delay (WCD) is derived using the network calculus (NC) approach considering the relative relationships between window offsets for consecutive nodes and evaluated under a realistic vehicle use case. While guaranteeing latency deadline for TT traffic, the FWOS algorithm defines the maximum allowable OR that maximizes the bandwidth available for unscheduled transmission. Even under a non-overlapping scenario, less pessimistic latency bounds have been obtained using FWOS than the latest related works.

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