Dynamic Real-time Applications Research Articles

Quality of Services Based on Intelligent IoT WLAN MAC Protocol Dynamic Real-Time Applications in Smart Cities.

The future directions and challenges for 6G-enabled wireless communication for IoT applications are mainly focused on quality of service (QoS). The selection criteria of mobility management (MM) protocol are mainly the total duration of the delay and packet loss rate during the MM procedure. This is called intelligent handover (IH) to designate a relay with a minimum delay. To solve the problem of handover, media access control (MAC) protocols are used to provide an intelligent protocol for QoS in real-time application in mobility. Moreover, changing the parameter to find the best protocol for mobile stations in WLAN is a good choice. This paper proposed a new QoS structure for the point coordination function that is based on a new intelligent enhanced distribution coordination function that suites with dynamic real-time applications and services. The paper addresses the distributed coordination function (DCF) with QoS-based intelligent mobility management in stations and other scenarios with enhanced distribution coordination function (EDCF) to find the result of throughput, retransmission attempts, delay, and data droop. In this paper, the remote topology comprises a few remote stations and one base station within the remote LAN. All remote stations are found that each station can distinguish a transmission from any other station, and there is portability within the proposed intelligent framework.

VO2 based dynamic tunable absorber and its application in switchable control and real-time color display in the visible region.

Metasurface-based near perfect absorbers exhibit a wide range of potential applications in the fields of solar energy harvesting, thermal images and sensors due to their unique absorption regulation function. However, absorption characteristics of devices are locked by the device structure, leading to the limitation in real-time dynamic applications. In this work, we integrate the phase change material VO2 thin film into the metal-insulator-metal structured metasurface based absorber, and design a fully visible band switchable dynamically tunable absorber (DTA). By controlling the phase transition of VO2, the DTA can realize a novel switch function in the full band of visible light (400 ∼ 780 nm), with absorption contrast ranges from 42% to 60%. Furthermore, via accurate structural parameter control, the vivid cyan, magenta, and yellow pixels based on the VO2 DTA are designed and proposed in the real-time optical anti-counterfeiting, exhibiting outstanding characteristics of anti-glare interference and real-time encryption ability. The absorption spectrum and local electric field are simulated and analyzed to study the internal operation mechanism of DTA. The dynamic absorption adjustable function is attributed to the synergistic effect of insulator-metal transition of VO2 and Fabry-Pérot resonance of absorber.

A Continuous Velocity-Based Friction Model for Dynamics and Control With Physically Meaningful Parameters

Friction is an important part of many dynamic systems, and, as a result, a good model of friction is necessary for simulating and controlling these systems. A new friction model, designed primarily for optimal control and real-time dynamic applications, is presented in this paper. This new model defines friction as a continuous function of velocity and captures the main velocity-dependent characteristics of friction: the Stribeck effect and viscous friction. Additional phenomena of friction such as microdisplacement and the time dependence of friction were not modeled due to the increased complexity of the model, leading to reduced performance of real-time simulations or optimizations. Unlike several current friction models, this model is C1 continuous and differentiable, which is desirable for optimal control applications, sensitivity analysis, and multibody dynamic analysis and simulation. To simplify parameter identification, the proposed model was designed to use a minimum number of parameters, all with physical meaning and readily visible on a force–velocity curve, rather than generic shape parameters. A simulation using the proposed model demonstrates that the model avoids any discontinuities in force at initial impact and the transition from slipping to sticking.

A Secure Service Provisioning Framework for Cyber Physical Cloud Computing Systems

Cyber physical systems (CPS) are mission critical systems engineered by combination of cyber and physical systems respectively. These systems are tightly coupled, resource constrained systems and have dynamic real time applications. Due to the limitation of resources, and in order to improve the efficiency of the CPS systems, they are combined with cloud computing architecture, and are called as Cyber Physical Cloud Computing Systems (CPCCS). These CPCCS have critical care applications where security of the systems is a major concern. Therefore, we propose a Secure Service provisioning architecture for Cyber Physical Cloud Computing Systems (CPCCS), which includes the combination of technologies such as CPS, Cloud Computing and Wireless Sensor Networks. In addition to this, we also highlight various threats/attacks; security requirements and mechanisms that are applicable to CPCCS at different layers and propose two security models that can be adapted in a layered architectural format.

Research on ambiguity resolution aided with triple difference

The ambiguity resolution in the field of GPS is investigated in detail. A new algorithm to resolve the ambiguity is proposed. The algorithm first obtains the floating resolution of the ambiguity aided with triple difference measurement. Decorrelation of searching space is done by reducing the ambiguity covariance matrix's dimension to overcome the possible sick factorization of the matrix brought by Z-transformation. In simulation, the proposed algorithm is compared with least-squares ambiguity decorrelation adjustment (LAMBDA). The result shows that the proposed algorithm is better than LAMBDA because of lesser resolving time, which approximately reduces 20% resolving time. Thus, the proposed algorithm adapts to the high dynamic real-time applications.

Application Scenarios in Streaming-Oriented Embedded-System Design

A design method for handling increasingly dynamic real-time embedded-system applications can help developers cope with stringent system and market requirements. This method groups an application's operation modes into application scenarios and describes how to incorporate them in the overall design process. An automated scenario-based design trajectory reduces the energy consumption of a streaming application running on a single processor platform via dynamic voltage and frequency scaling.

Adaptive resource management for dynamic distributed real-time applications

The dynamic distributed real-time applications run on clusters with varying execution time, so re-allocation of resources is critical to meet the applications's deadline. In this paper we present two adaptive recourse management techniques for dynamic real-time applications by employing the prediction of responses of real-time tasks that operate in time sharing environment and run-time analysis of scheduling policies. Prediction of response time for resource reallocation is accomplished by historical profiling of applications' resource usage to estimate resource requirements on the target machine and a probabilistic approach is applied for calculating the queuing delay that a process will experience on distributed hosts. Results show that as compared to statistical and worst-case approaches, our technique uses system resource more efficiently.

Mapping the MPEG-4 visual texture decoder: a system-level design technique based on heterogeneous platforms

This article presents automated techniques supporting the design-time scheduling phase of a unique approach for managing concurrent tasks of dynamic real-time applications mapped on a heterogeneous platform with different types of software and hardware components. This approach is based on design-time exploration, which results in a set of schedules and assignments for each task, represented by Pareto curves. At run-time, a low complexity scheduler selects an optimal combination of working points, exploiting the dynamic and nondeterministic behavior of the system. The combined approach leads to significant overall power savings compared to state-of-the-art dynamic voltage scaling techniques. The design-time generated Pareto curves can also be used by the application designer to effectively make quantitative tradeoffs between system cost and performance.

MATADOR: AN EXPLORATION ENVIRONMENT FOR SYSTEM-DESIGN

We present a modular platform simulation environment to estimate the energy consumption and performance of distributed systems in a Systems-on-Chip context. We use the simulation environment to support the development of our high-level design methodologies. More in particular, we steer and verify the development of a task-level data transfer and storage methodology, the development of a task-level scheduling methodology and the development of an instruction memory management methodology. All of these methodologies are focussed on reducing the overall energy consumption of the complex dynamic system on a heterogeneous platform architecture. Compared to research in the academic and industrial context, our contribution is to integrate in a scalable way existing energy and performance simulators of the components of a heterogeneous multiprocessor SoC. Also a novel instruction memory hierarchy is included. The simulation environment consists of multiple processing nodes connected to a distributed memory hierarchy. To reduce the energy consumption of the system, both the processing nodes as well as the memory architecture can be varied: the processing voltage of each node can be tuned and the memory hierarchy can be fully customized. The integration of dynamic real-time applications on this platform is simplified by the availability of a multi-processor RTOS. The use of the simulator to develop our high-level design methodologies is illustrated on real-life multimedia applications.

Framework for CORBA Extensions to Support Real-Time Object-Oriented Applications

Object-oriented distributed real-time applications require enforcement of end-to-end timing constraints on service requests from clients to servers. Thus, timing aspects should be integrated and handled by CORBA which is a standard to support distributed object-oriented applications. In spite of the release of real-time CORBA (RT-CORBA) specification, a few vendors have ported their ORBs (Object Request Brokers) to real-time operating systems. In this paper we analyze existing RT-CORBA implementations, and we propose a framework that integrates the main components (scheduling, real-time communication, end-to-end quality of service providing, etc.) necessary for implementation of RT-CORBA to support static and dynamic real-time applications.

Object-oriented real-time systems: concepts and examples

The problems associated with developing real-time software systems, including ensuring predictable real-time behavior under both normal and abnormal operating conditions, are outlined. The management of temporal complexity, structuring of dynamic real-time applications, object-oriented models, object-oriented real-time languages, and the requirements for real-time object-oriented models are discussed. Chaos, an object-based language and programming/execution paradigm designed for dynamic real-time applications, is described. >

Defining Real-time: A Background For The Design Of Real-time Knowledge-based Systems

Dynamic real-time applications feature non-deterministic aspects that naturally match with the exploitation of the knowledge-based system technology. On the other hand, the use of the knowledge-based system technology makes even harder most of the difficulties of dynamic real-time system design. Because of this tradeoff, the design of real-time knowledge-based systems is still an advanced research topic. A fundamental open problem is the lack of a settled definition of the concept of real-time, which definitely states the requirements a software system must necessarily fulfill in order to be regarded as a certified real-time system. This paper proposes an original definition of real-time system, partly inspired by state-of-the-art definitions and partly based on an innovative problem decomposition perspective. Such definition is more formal than those that can be found in the literature, while being powerful enough to capture most of the real-time systems of practical interest in engineering domains.