In operating systems, resource managers are developed according to simplicity, low overhead, low memory footprint, extensibility and efficiency. Thread schedulers are designed and developed following these implementat...
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ISBN:
(纸本)9781509024803
In operating systems, resource managers are developed according to simplicity, low overhead, low memory footprint, extensibility and efficiency. Thread schedulers are designed and developed following these implementation-related guidelines. The performance of the implementation is then tested over a set of benchmarks. However, the ability to provide real-time guarantees of these policies is rarely properly quantified. To respond to this need, we developed a publicly available tool (rt-muse), that analyzes timing properties extracted from the execution of a set of threads and it computes the lower/upper bounds to the supply function offered by the execution platform. Also, rt-muse evaluates the impact of many application and platform characteristics including the scheduling algorithm, the amount of available resources, the usage of shared resources, the memory access overhead, etc. In the experiments, we show the impact of Linux scheduling classes, shared data and application parallelism, on the delivered computing capacity. The tool provides useful insights on the runtime behavior of the applications and scheduler. For example, we detected unexpected starvation of threads scheduled by the Linux round-robin class.
The frequency, time and places of charging have large impact on the Quality of Experience (QoE) of EV drivers. It is critical to design effective EV charging scheduling system to improve the QoE of EV drivers. In orde...
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The frequency, time and places of charging have large impact on the Quality of Experience (QoE) of EV drivers. It is critical to design effective EV charging scheduling system to improve the QoE of EV drivers. In order to improve EV charging QoE and utilization of CSs, we develop an innovative travel plan aware charging scheduling scheme for moving EVs to be charged at Charging Stations (CS). In the design of the proposed charging scheduling scheme for moving EVs, the travel routes of EVs and the utility of CSs are taken into consideration. The assignment of EVs to CSs is modeled as a two-sided many-to-one matching game with the objective of maximizing the system utility which reflects the satisfactory degrees of EVs and the profits of CSs. A Stable Matching Algorithm (SMA) is proposed to seek stable matching between charging EVs and CSs. Furthermore, an improved Learning based On-LiNe scheduling Algorithm (LONA) is proposed to be executed by each CS in a distributed manner. The performance gain of the average system utility by the SMA is up to 38.2% comparing to the Random Charging scheduling (RCS) algorithm, and 4.67% comparing to Only utility of Electric Vehicle Concerned (OEVC) scheme. The effectiveness of the proposed SMA and LONA is also demonstrated by simulations in terms of the satisfactory ratio of charging EVs and the the convergence speed of iteration.
Network applications in highly mobile systems need to employ online algorithms that do not rely on precise predictions about future events. In order to meet hard performance guarantees in the presence of unknown futur...
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ISBN:
(纸本)9781509017478
Network applications in highly mobile systems need to employ online algorithms that do not rely on precise predictions about future events. In order to meet hard performance guarantees in the presence of unknown future events, common practice is to add redundancy to the systems. In this paper, we define a new competitive ratio that reflects the amount of redundancy needed to ensure some given performance guarantees. We study two special applications, namely, online job allocations in cloud computing and online scheduling in delayed mobile offloading, and propose online algorithms for each of them. We prove that our algorithms are optimal. By comparing our algorithms with commonly used other policies, we also show that our policies need much less redundancy than those commonly used policies to provide the same degree of performance guarantees.
Transmitting a good quality voice over wireless networks is a challenge for service providers. Long Term Evolution (LTE), also known as one of the beyond 4G wireless network technology, is designed to have a greater d...
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ISBN:
(纸本)9781509024629
Transmitting a good quality voice over wireless networks is a challenge for service providers. Long Term Evolution (LTE), also known as one of the beyond 4G wireless network technology, is designed to have a greater delivery service for multimedia, voice, and video applications to end users. Therefore, modern cellular networks are expected to support both voice and a growing volume of data traffic. However, LTE architecture does not support native circuit switching services and relies on the IP Multimedia Subsystem (IMS) for supporting voice. Voice over Internet Protocol (VoIP) is particularly used in LTE for the delivery of the voice. In fact, one of the major challenges for VoIP over LTE is to guarantee the Quality of Service (QoS) of the VoIP calls. However, the QoS of the Voice/video/multimedia in the intricacy wireless network was studied and comparisons among the scheduling algorithms were made in this study. The evaluation of a single and thereafter multi-cells was considered for different flows such as Best Effort, VoIP and Video in mobile environment (at low and high speeds) using the LTE-Simulator. Our simulation results showed that the performance of the scheduling algorithms could enhance voice (and video) delivery quality.
We investigate the performance of First-In, First-Out (FIFO) queues over wireless networks. We characterize the stability region of a general scenario where an arbitrary number of FIFO queues, which are served by a wi...
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We investigate the performance of First-In, First-Out (FIFO) queues over wireless networks. We characterize the stability region of a general scenario where an arbitrary number of FIFO queues, which are served by a wireless medium, are shared by an arbitrary number of flows. In general, the stability region of this system is non-convex. Thus, we develop a convex inner-bound on the stability region, which is provably tight in certain cases. The convexity of the inner bound allows us to develop a resource allocation scheme; dFC. Based on the structure of dFC, we develop a stochastic flow control and scheduling algorithm; qFC. We show that qFC achieves optimal operating point in the convex inner bound. Simulation results show that our algorithms significantly improve the throughput of wireless networks with FIFO queues, as compared to the well-known queue-based flow control and max-weight scheduling.
This paper proposes a new scheduling algorithm for shipping operations in steel works. In the shipping operation, steel products are handled by various kinds of machines, for example, overhead cranes in warehouses, sp...
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As cloud services grow to span more and more globally distributed datacenters, there is an increasingly need for scheduling algorithms to automatically place tasks across these datacenters. In geo-distributed cloud, t...
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ISBN:
(纸本)9781509036547
As cloud services grow to span more and more globally distributed datacenters, there is an increasingly need for scheduling algorithms to automatically place tasks across these datacenters. In geo-distributed cloud, the limited WAN bandwidth has become the major bottleneck in fast big data analytics. The scheduling algorithm needs to minimize the global completion time, by jointly optimizing task scheduling and WAN data transfer. In this paper, we model the task scheduling as a community detection problem, with respect to the dependency relations between task, data, and datacenters, and propose a Community Detection-based scheduling (CDS) algorithm, which is able to minimize the WAN data transfer volume. We utilize the real China-Astronomy-Cloud network to evaluate the proposed algorithms. Experimental results show that we can reduce the total data transfer volume by up to 40.7%, and the global completion time by up to 35.8%, compared with the Hypergraph Partition-based scheduling algorithm and the greedy scheduling algorithm.
The key factor which rules the cloud's performance is the workflow scheduling, one of the well-known problems have proven to be NP-complete. Many algorithms in the literature have been targeting the workflow sched...
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In recent years, people with cognitive disability has increased rapidly. The increase of them considerably affects the family and society that interact with the cognitively disabled person. Children with developmental...
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ISBN:
(纸本)9781509024803
In recent years, people with cognitive disability has increased rapidly. The increase of them considerably affects the family and society that interact with the cognitively disabled person. Children with developmental disability or patients with dementia need to monitor and track their behaviors for their safety. We design smart tracking system which effectively can help to trace their location and to monitor their activities. The system applies a wireless sensor network with an efficient sensor deployment method and an adaptive packet scheduling algorithm. In addition, it provides the real-time monitoring to observe their situation and gives a quick alerting to them and caregivers. In this paper, we present an overview of an integrated framework.
The mechanisms of allocating the resources in Long Term Evolution (LTE) cellular networks are very critical issues, because scheduling algorithms have the main responsibility for determining how to allocate radio reso...
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The mechanisms of allocating the resources in Long Term Evolution (LTE) cellular networks are very critical issues, because scheduling algorithms have the main responsibility for determining how to allocate radio resources for different users. In this work a dynamically adopted Proportional Fair (PF) scheduling strategy for capacity enhancement of LTE system is proposed. Performance comparison with the conventional PF downlink scheduler and the Best-Channel Quality Indicator (Best-CQI) scheduling algorithm is presented. The results of the simulation demonstrate that the introduced scheduling strategy enhances the overall system capacity and also provides a high level of fairness among all active Users Equipment (UEs). The proposed algorithm improves the average cell throughput by more than 31 %, with a slight degradation in the fairness level with respect to the conventional PF scheduling strategy.
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