In this article, authors present the results of testing the modified HTB traffic control algorithm in an experimental setup. The algorithm is implemented as a Linux kernel module. An analysis of the experimental resul...
详细信息
ISBN:
(纸本)9781728180960
In this article, authors present the results of testing the modified HTB traffic control algorithm in an experimental setup. The algorithm is implemented as a Linux kernel module. An analysis of the experimental results revealed the effect of uneven packet loss in priority classes. In the second part of the article, the authors propose a solution to this problem by applying a distribution scheme for the excess of tokens, according to which excess class tokens are given to the leaf with the highest priority. The new modification of the algorithm was simulated in the AnyLogic environment. The results of an experimental study demonstrated that dividing the excess tokens of the parent class between daughter classes is less effective in terms of network performance than allocating the excess tokens to a high-priority class during the competition for tokens between classes. In general, a modification of the HTB algorithm that implements the proposed token surplus distribution scheme yields more consistent delay times for the high-priority class.
Industry 4.0 is changing the way to produce, pursuing increased flexibility of production systems and an ever-greater decision-making autonomy of the machines. The aim is to achieve high level of performances even in ...
详细信息
Industry 4.0 is changing the way to produce, pursuing increased flexibility of production systems and an ever-greater decision-making autonomy of the machines. The aim is to achieve high level of performances even in market scenarios requiring high level of customization, as the Mass Customisation (MC) paradigm imposes. Current hierarchical Manufacturing Planning and Control (MPC) systems showed limits in catching this goal, primarily due to their structural lack of flexibility. For this reason, the interest in the hybrid MPC architectures like the semi-heterarchical one is increasing. The objective of this work is to contribute to the design of such an architecture, proposing a new scheduling mechanism for the lowest decisional level. This mechanism, differently from the ones already proposed in the literature, schedules the next jobs to be admitted in the system choosing them by couples. The proposed rule has been tested through a simulation environment in three different scenarios of demand generation rate. The results showed an improvement in demand absorption and productivity compared to the rules used up to now.
The rapid growth of IoT devices and applications with data-intensive processing has led to energy consumption and latency concerns. These applications tend to offload task processing to remote Data Centers in the Clou...
详细信息
ISBN:
(纸本)9783030653101;9783030653095
The rapid growth of IoT devices and applications with data-intensive processing has led to energy consumption and latency concerns. These applications tend to offload task processing to remote Data Centers in the Cloud, distant from end-users, increasing communication latency and energy costs. In such a context, this work proposes a dynamic cost model to minimize energy consumption and total elapsed time for IoT devices in Mobile Edge Computing environments. The solution presents a Time and Energy Minimization Scheduler (TEMS) that executes the cost model, validated through simulation, which resulted in a reduction in energy consumption by up to 51.61% and in task completion time by up to 86.65%.
This contribution presents a new Modified Compressed Sparse Row (MCSR) format designed for multi-core FPGA-based hardware accelerators for the calculation of Sparse Matrix Vector Multiplication (SMVM). Current state-o...
详细信息
ISBN:
(数字)9781728133201
ISBN:
(纸本)9781728133201
This contribution presents a new Modified Compressed Sparse Row (MCSR) format designed for multi-core FPGA-based hardware accelerators for the calculation of Sparse Matrix Vector Multiplication (SMVM). Current state-of-the-art methods suffer from memory bandwidth bottlenecks affecting the speed of parallel SMVM. The salient feature of the proposed MCSR format is that an extension of Hu's scheduling algorithm has been adopted to relocate the non-zero entries of the sparse matrix to ensure a continuous flow of data at each core, thus eliminating redundant memory requests and unnecessary intermediate result storage. Consequently, effects of the memory bandwidth bottleneck are reduced. Dedicated Multiplication and Accumulation (MAC) cores have been used in the experiments presented in this paper. The correct functionality of the proposed method is verified through Modelsim simulations. A thorough investigation of the effectiveness of the new format was carried out using a number of case studies with variable sparsities and matrix sizes, resulting to a speedup that reaches up to four orders of magnitude compared with an Intel i7 CPU.
The performance of multi-core real-time operating system is greatly affected by the quality of tasks scheduling algorithm. Directed acyclic graph (DAG) task model can better represent the dependency between subtasks i...
详细信息
ISBN:
(纸本)9781728165790
The performance of multi-core real-time operating system is greatly affected by the quality of tasks scheduling algorithm. Directed acyclic graph (DAG) task model can better represent the dependency between subtasks in multi-core real-time system. However, the scheduling algorithm previously applied to independent sequential tasks is no longer suitable for this kind of tasks, the efficient DAG tasks scheduling algorithm has become the current research hotspot. This paper discusses the stretching algorithm with excellent performance, and on the basis of the stretching algorithm, an improved stretching algorithm is proposed to overcome its shortcoming of ignoring dependence between subtasks. The performance optimization is verified by simulation experiments.
Approximate computing is a research area which investigates a wide spectrum of techniques to trade off computation time for better accuracy. This paper models the accuracy of the computation as a concave, possibly non...
详细信息
Approximate computing is a research area which investigates a wide spectrum of techniques to trade off computation time for better accuracy. This paper models the accuracy of the computation as a concave, possibly non-differentiable function of job size to decide the accuracy of each job as well as the scheduling decision of the jobs on heterogeneous servers. The two metrics of interest are the makespan of the completion time of the jobs and the weighted accuracy of the different jobs. For a given makespan, an algorithm is provided that achieves the optimal weighted accuracy of computations, thus providing an optimal tradeoff between the two objectives for preemptive scheduling of approximate computing jobs on multiple servers. The proposed algorithm decides the task sizes of each of the jobs, which gives the accuracy of the jobs in addition to the schedule of these partial jobs on the servers. (C) 2019 Elsevier B.V. All rights reserved.
Time-Sensitive Networking (TSN), which evolves from the Ethernet standards, has been developed to ensure deterministic transmission in data networks. Asynchronous Traffic Shaping (ATS) extends the conventional synchro...
详细信息
Time-Sensitive Networking (TSN), which evolves from the Ethernet standards, has been developed to ensure deterministic transmission in data networks. Asynchronous Traffic Shaping (ATS) extends the conventional synchronized TSN with an asynchronous scheduler to guarantee a bounded transmitting delay. In this work, we present a Field Programmable Gate Arrays (FPGA) implementation of a TSN scheduling entity, which leverages ATS for the frame forwarding process. We explore the ATS design by function blocks and compare it with a benchmark design utilizing strict-priority scheduling. In terms of operating frequency, our results indicate that strict-priority scheduling performs 1.05% to 9.56% higher maximum frequency than ATS with the same configurations. Regarding resource utilization, ATS consumes 51% to 119% more logic blocks and 51% to 101% more registers than strict-priority scheduling. Based on the synthesis and fitting results from Register-Transfer Level (RTL) simulations, we provide a general vision of designing and implementing considerations of the ATS function. Specifically, we show the influences of the buffer and bus width configuration on the FPGA implementation scale and data rate.
The introduction of a consortium blockchain-based agricultural machinery scheduling system will help improve the transparency and efficiency of the data flow within the sector. Currently, the traditional agricultural ...
详细信息
The introduction of a consortium blockchain-based agricultural machinery scheduling system will help improve the transparency and efficiency of the data flow within the sector. Currently, the traditional agricultural machinery centralized scheduling systems suffer when there is a failure of the single point control system, and it also comes with high cost managing with little transparency, not leaving out the wastage of resources. This paper proposes a consortium blockchain-based agricultural machinery scheduling system for solving the problems of single point of failure, high-cost, low transparency, and waste of resources. The consortium blockchain-based system eliminates the central server in the traditional way, optimizes the matching function and scheduling algorithm in the smart contract, and improves the scheduling efficiency. The data in the system can be traced, which increases transparency and improves the efficiency of decision-making in the process of scheduling. In addition, this system adopts a crowdsourcing scheduling mode, making full use of idle agricultural machinery in the society, which can effectively solve the problem of resource waste. Then, the proposed system implements authentication access mechanisms, and allows only authorized users into the system. It includes transactions based on digital currency and eliminates third-party platform to charge service fees. Moreover, participating organizations have the opportunity to obtain benefits and reduce transaction costs. Finally, the upper layers supervision improves the efficiency and security of consensus algorithm, allows supervisors to block users with malicious motives, and always ensures system security.
The pervasiveness of public displays is prompting an increased need for "fresh" content to be shown, that is highly engaging and useful to passerbys. As such, live or time-sensitive content is often shown in...
详细信息
ISBN:
(纸本)9781450367516
The pervasiveness of public displays is prompting an increased need for "fresh" content to be shown, that is highly engaging and useful to passerbys. As such, live or time-sensitive content is often shown in conjunction with "traditional" static content, which creates scheduling challenges. In this work, we propose a utility-based framework and a novel scheduling algorithm for handling live and non-live content on public displays. We also experimentally evaluate our proposed algorithm against a number of alternatives under a variety of workloads.
In recent years, wireless sensor networks have become attractive to industries due to their low operational cost and potential productivity gain. Designed to operate on batteries, some devices can operate several year...
详细信息
ISBN:
(纸本)9781728108643
In recent years, wireless sensor networks have become attractive to industries due to their low operational cost and potential productivity gain. Designed to operate on batteries, some devices can operate several years without requiring human intervention. However, scheduling reliable wireless communication becomes challenging when considering the energy consumption of the devices. Furthermore, actual industrial network deployments and data traffic are often unpredictable as they greatly vary depending on the field of application. While application-specific solutions exist, an adaptive and application-agnostic solution is preferred. This work proposes a new wireless scheduling algorithm to address the reliability issue in wireless sensor networks, while considering the energy cost. The algorithm operates as a swarm and optimizes the number of communication resources allocated to each device in a short time. Tested on the IEEE 802.15.4 TSCH communication protocol, the algorithm is compared to the Minimal scheduling Function (MSF), state of the art of TSCH scheduling. The algorithm highlights a strong performance in terms of packets reception ratio and latency. Furthermore, it shows an increased energy efficiency measured in current consumed per delivered packet.
暂无评论