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To satisfy growing computational demands of modern applications, significant enhancements have been introduced in the contemporary processor architectures with the aim to increase their attainable performance, such as increased number of cores, improved capability of memory subsystem and enhancements in the processor pipeline [1]. Therefore, the performance improvements are usually coupled with an...
Piezoelectric actuator is considered as the main device for the high precision positioning system due to its rapid response, high stiffness and ultra-high resolution. However, the intrinsic hysteresis behavior of piezoelectric actuator can seriously degrade the trajectory-tracking precision. Moreover, the model weights of the Prandtl-Ishlinskii (PI)'s play operator versus velocity are nonlinear which...
This paper proposes an approach to solve the problem of LTE EPS network parametric synthesis taking into account self-similar properties of multiservice traffic. The problem is solved with the known source data such as network topology, traffic routes, statistical data on the demand for information and communication services. The article proposes the calculation expressions to determine the parameters...
A key principle for optimizing network performances is to understand the relationship between network topology, configuration parameters, and their influence on the behavior of network protocols. While an attractive approach to this problem is to use formal models of protocols in combination with mathematical optimization, such methods are often limited by either poor scalability or approximations...
Next generation of mobile technologies demands high date rates and low round trip times. Therefore, we analyze deployments that offer these performance capabilities. We consider the fundamental issue of the expenses of the network's installation, maintenance and operation. We calculate the costs of Distributed Antenna Systems (DAS) and small cells by describing updated cost models for each one. We...
The spectral filter bandwidth plays a crucial role in the pulse formation in all-normal-dispersion fiber lasers. It is affected by the parameters of the mode locker in the laser cavity. In this paper, a modified analytical model is developed and used to study the dependence of the spectral bandwidth on the small signal absorption, and the saturation power of a lumped saturable absorber. A comparison...
Infrastructure as a service (IaaS) is a form of cloud computing, which converts physical machines (PMs) to various types of resources by virtualization technology, and delivers these resources to customers by a on-demand way. However, different customer requirements complicate the usage of resources. In this paper, we employ a high level formalization way, Performance Evaluation Process Algbra (PEPA),...
In this paper, we propose an analytic model that takes as inputs a) a parametric microarchitecture-independent characterization of the target workload, and b) a hardware configuration of the core and the memory hierarchy, and returns as output an estimation of processor-core performance. To validate our technique, we compare our performance estimates with measurements on an Intel® Xeon® system. The...
Under the constraints of limited bandwidth and exponentially rising user demand, there is a dire need to maximize throughput. Maintaining Quality of Service (QoS) in a communication network demands congestion control with high accuracy. This paper focuses on this challenging task that incorporates design of effective congestion controller to reduce packet loss in cognitive radio networks. Limited...
In this paper, we have proposed a localized dual-mode model to study push-pull modulation responses of DFB lasers. Numerical simulation shows that, with properly designed and controlled photon-photon resonance, an ultra-broad 3dB modulation bandwidth up to 50GHz is achievable.
In this paper we show how to analytically model two widely used distributed matrix-multiply algorithms, Cannon's 2D and Johnson's 3D, implemented within the Intel Concurrent Collections framework for shared/distributed memory execution. Our precise analytical model proceeds by estimating the computation time and communication times, taking into account factors such as the block size, communication...
Next-generation digital broadcasting system transmits the DASH segment files. Delays and inefficient use of resources are the major challenges in the transmission of DASH segment files in broadcasting systems. Because the size of DASH segment files varies even though the files have the same quality, and broadcasting systems uses the fixed resource. Delay is an important problem in broadcasting systems...
A current-mode approach is often used when designing front-end electronics for Silicon Photomultipliers, to cope with the peculiar features of this kind of detectors. Very low input resistance Rin and bandwidth BW as large as possible are classic design choices for the preamplifier, since it is commonly assumed that timing accuracy performance are optimized if this strategy is adopted. In our study,...
Reliability is a critical metric in the design and development of scale-out data storage clusters. A general multiway replication-based declustering scheme has been widely used in enterprise large-scale storage systems to improve the I/O parallelism. Unfortunately, given an increasing number of node failures, how often a cluster starts losing data when being scaled-out is not well investigated. In...
Performance modelling is a useful tool in the lifeycle of high performance scientific software, such as weather and climate models, especially as a means of ensuring efficient use of available computing resources. In particular, sufficiently accurate performance prediction could reduce the effort and experimental computer time required when porting and optimising a climate model to a new machine.
With the development of wireless broadband access, OFDMA technology is widely used for the next generation telecommunication systems. In this paper, we focus on analyzing the performance of contention-based services in IEEE 802.16 OFDMA networks with bulk services. We derive various performance measures such as queue utilization in an subscriber station, probability of unsuccessful bandwidth request,...
Understanding performance scalability in MapReduce applications presents a challenging problem. The difficulty lies in the distributed locations of input data and the distributed compute resources that utilize varied network substrates. User-defined Map and Reduce stages, with numerous application parameters, further complicate the problem. Using small datasets and limited test runs to understand...
Cloud networking typically leads to scenarii where a large number of TCP connections share a common bottleneck link. In this paper, we focus on the case of TCP Cubic, which is the default TCP version in the Linux kernel. TCP Cubic is designed to better utilize high bandwidth-delay product path in an IP network. To do so, Cubic modifies the linear window growth function of legacy TCP standards, e.g...
Fluid models have gained popularity in the performance modeling of computing systems and communication networks. When the model under study consists of many different types of agents, the size of the associated system of ordinary differential equations (ODEs) increases with the number of types, making the analysis more difficult. We study this problem for a class of models where heterogeneity is expressed...
We consider the problem of how to enable computer architects and algorithm designers to reason directly and analytically about the relationship between high-level architectural features and algorithm characteristics. We propose a modeling framework designed to help understand the long-term and high-level impacts of algorithmic and technology trends. This model connects abstract communication complexity...
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