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With the successful deployment of IEEE 802.11a/b/g wireless local area networks (WLANs) and the pent-up market demand for high speed wireless access, the IEEE 802.11n protocol has emerged as a promising standard with major enhancements. In order to scale to the high physical layer transmission rate of up to 600 Mbps, the current medium access control (MAC) protocol requires significant improvements...
This paper presents a modeling and analysis methodology for the current loop control design for three-phase high power converters with extremely low sampling ratios. It applies the complex transfer function and the double-sided Frequency-Response-Functions to quantitatively characterize the system such as the phase margin, dynamic performance and the noise immunity. Both standard PI control and PI...
In order to study the influence of different vehicles to incident delay, traffic simulation is applied to make the delay predictions. Three major parts, respectively the establishment of simulation platform and parameter calibration, survey and calculation of traffic data, and case study, are described in the paper. For the establishment of simulation platform and parameter calibration, at first,...
This paper investigates the applicability of a mixed effects model in predicting Quality of Experience (QoE) in World Wide Web based multi-media services. An analysis is presented on objective factors and a human factor that may impact on outcomes of observations as fixed effects, population mean, and random effects, group specific, and account for a correlation structure of variations amongst users...
A large-scale deployment of femto BSs (FBSs) will result in the substantial energy consumption. One fairly intuitive way to improve energy efficiency for femtocells is a sleep mode where the FBS periodically transmits pilot signal especially in low traffic scenario. Nevertheless, it is inefficient when not involved an active call in the FBS coverage area. To address this issue, this paper proposes...
The IEEE 802.11ai is an upcoming fast initial link setup (FILS) amendment that could enable a STA to achieve secure link setup in less than 100 ms. A successful link setup process will then allow the STA to send IP traffic with a valid IP address through the AP. In this paper, we first present a performance analysis on how well the legacy 802.11 can support FILS. We then demonstrate that the rate...
Several reliable packet routing approaches have been studied to achieve a high reliable VANET by using the Car-to-car communications and Inter-Vehicle Communications. VANET suffers from high mobility, diverse road topologies, and wireless interference, and thus significantly degrades the connectivity of packet transmissions and network performance. The mathematical analysis can help the approach efficiency,...
In multipath channels, paths often arrive in clusters. An early model that exhibits clustering was proposed by Saleh and Valenzuela in 1987, and since then, several extensions have been developed. Although these models are straightforward to simulate, little analysis of them has been carried out. Here, a generalized multipath-cluster channel model is proposed that subsumes the Saleh-Valenzuela model...
Networked control systems (NCS) are in existence for quite some time. The network-induced delays and packet drops; and their effect on control system's performance has been a burning topic for last one decade. Dependability in context of NCS has not got much attention. While it is an important aspect of NCS intended to be used in critical application. The paper reviews the present state of developments...
To analyze and compare buffer size requirements of different cache coherence policies will provide beneficial guidelines for NoC design. However, it is not an easy task, because 1)packet flows generated by cache coherence events do not conform to the Poisson process, traditional queue theorem can't be applied to the performance analyzing for the NoCs that support cache coherence, 2) broadcast or multicast...
Under emergency situations, citizens are often forced to evacuate an inhabited area for their own safety. During this process, drivers' behavior becomes a very important factor determining vehicle movements in the affected area. In this research, the impact of driver aggressiveness on traffic flow properties related to evacuation, such as travel time to the safe zones, is modeled through microscopic...
Cloud Computing (CC) is a technological phenomenon that is becoming more and more important. Also Small and Medium Enterprises (SMEs) can increase their competitiveness by taking advantage of CC. This new computing approach promises to provide many advantages, and many SMEs are encouraged to use it. However, CC is still in its early stage -- for this reason we think that it is very important to study...
Recently overlay/underlay framework in Cognitive Radio (CR) have been studied and demonstrated the benefits such as spectrum efficiency and channel capacity maximization. We assume Secondary Users (SUs) can choose to either acquire a dedicated spectrum with constant payment or to use a Primary User (PU) band for free. However, using PU band yields delayed transmission cost. In this paper, we apply...
The introduction of communication systems to power system controllers have brought in another layer of complexity in their design and operation. In this paper a Plug-in Hybrid Electric Vehicle (PHEV) charging facility is studied. A linearized model of the facility is built including both the dc/dc and dc/ac converters of the Distributed Energy Resources (DER). In addition, a control strategy that...
This paper presents two adaptive two-stage fuzzy controllers for traffic signals at isolated intersections. Firstly, a two-stage combination fuzzy controller is designed. For traffic status variables in two-stage controller leading to the inefficiency of traffic states weakening under low traffic flow, the controller introduces 0–1 combination and determines the combination of traffic status variables...
The lack of available and practical analysis about some regular knowledge of mobility models has limit their applications to mobile ad hoc networks. As the mobility models have the great significance effects on the network performance, and meanwhile, existing in-depth researches are mostly based on the i.i.d. mobility model which is a way of globe move, the desire for the effective and reasonable...
Road maps are important for several applications in vehicular networks. As a consequence, an updated map is essential for a proper behavior of such applications. In this paper, we focus on a map update application based on an infrastructure-to-vehicle communication with a high mobility. In order to understand the application's behavior, we analyze different performance criteria: System Goodput, Packet...
By analyzing the signal lings exchange of SIP deeply, GSPN model of protocol is established for evaluating the performance of protocol, reducing call setup time of SIP and obtaining a tradeoff between the performance and the number of buffer. Basing on the model, markov chain of model is designed. Based on properties of constructed markov chain, performance of SIP is studied and evaluated through...
For scheduling services with different features and Qos constraints, this paper proposes a hybrid scheduling strategy, in which delay-sensitive services are granted preemptive priority and non-delay-sensitive services are granted non-preemptive priority. Theoretical analysis verified that preemptive scheme results in longer waiting length of queue.
With the process of non-functional properties research on real-time systems, resource estimation and analysis of real-time systems become a hotspot. Process Algebra is a formal method fitting for analyzing the functional properties of real-time systems, but it can not analyze the resource properties. Resource Timed Process Algebra (RTPA) proposed in this paper can handle it efficiently by extending...
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