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Terahertz frequency quantum cascade lasers offer a potentially vast number of new applications. To better understand and apply these lasers, a device-specific modeling method was developed that realistically predicts optical output power under changing current drive and chip temperature. Model parameters are deduced from the self-consistent solution of a full set of rate equations, obtained from energy-balance...
When local identification of a nonstationary ARX system is carried out, two important decisions must be taken. First, one should decide upon the number of estimated parameters, i.e., on the model order. Second, one should choose the appropriate estimation bandwidth, related to the (effective) number of input-output data samples that will be used for identification/tracking purposes. Failure to make...
Network simulation is an important technique for designing interconnection networks and communication libraries. Also network simulations are useful for the analysis of internal communication behavior in parallel applications. This paper introduces a new interconnection network simulator NSIM-ACE. This simulator enables us to evaluate RDMA directly while existing simulators do not have such capability...
We present the direct performance measurements of two popular weather forecast models, Weather Research and Forecast Model (WRF) and Models for Predictions Across Scales (MPAS) on Intel's Knight Landing Platform (KNL). WRF is widely evaluated over different platforms while the benchmarks of MPAS are still scarce. In this study we measured the running time of WRF and MPAS on the QCT Developer Cloud,...
Lysine succinylation is one of most important types in protein post-translational modification, which is involved in many cellular processes and serious diseases. However, effective recognition of such sites with traditional experiment methods may seem to be treated as time-consuming and laborious. Those methods can hardly meet the need of efficient identification a great deal of succinylated sites...
MeteoSwiss, the Swiss national weather forecast institute, has selected densely populated accelerator servers as their primary system to compute weather forecast simulation. Servers with multiple accelerator devices that are primarily connected by a PCI-Express (PCIe) network achieve a significantly higher energy efficiency. Memory transfers between accelerators in such a system are subjected to PCIe...
In dynamic bandwidth management based on traffic prediction, the traffic flows can be modeled as time-series data. State-of-the-art technique used in modeling this traffic flows is by using a linear model. In contrast, Recurrent Neural Network (RNN) has been the state-of-the-art technique in speech recognition, which data is also time-series. Therefore, we conjecture that the use of RNN can improve...
In this paper, we describe a prediction-based and provident service degradation algorithm for optical data center networks. We allocate the computing and network resources by considering the results of the prediction model and the provident service degradation jointly. The simulation results show that the theoretical prediction well matches the actual network traffic, and the average absolute value...
The first part of the paper discusses limitations of current Cloud offerings to efficiently support performance critical applications. A technical simulation from quantum chemistry is used as guiding example. The focus is on I/O performance being the major bottleneck for this kind of application and virtualisation in this area is much less developed compared to other hardware capabilities. Similar...
With the increasing number of geographically distributed scientific collaborations and the growing sizes of scientific data, it has become challenging for users to achieve the best possible network performance on a shared network. We have developed a model to forecast expected bandwidth utilization on high-bandwidth wide area networks. The forecast model can improve the efficiency of resource utilization...
Many multimedia applications over Mobile Ad hoc NETworks (MANETs) require Quality of Service (QoS) to meet real-time services. Accurate Available Bandwidth (AB) prediction and allocation of AB are important component for QoS provisioning which is affected by many factors such as latency, bandwidth, reliability, packet-loss, memory size, buffer cache, available capacity, and CPU speed. Media Access...
Data converters play an increasingly important role in communication systems. In order to support the demand for higher bandwidths and efficiency, recent work has focused both on architecture and ingenious circuit improvements that take advantage of the speed offered by nanometer-scale technologies.
Multithreaded applications have a wide variety of behavior, causing complex interactions with today's chip multiprocessor machines. Application threads may have large private working sets, and may compete for cache space and memory bandwidth. These threads benefit from large private caches. Other threads may share data or communicate, and thus, execute more quickly if using shared caches. Many applications...
Analytical modeling plays a unique and important role in computer architecture design, providing a first-order estimate, reducing the design search space size for simulation, or giving insights on basic relationships between various variables and parameters. However, current practices in using analytical models face considerable hurdles: models vary widely in types, predictive capability, and assumptions...
Network bandwidth is considered a valuable resource in most computer systems. To precisely detect network anomalies (with a few false alarms), an intrusion detection system requires reliable methods. A potential solution in predicting network bandwidth usage is using a time-series model with a threshold. This paper proposes a network anomaly detection technique based on SARIMA, a time-series model,...
Computers with hardware accelerators, also referred to as hybrid-core systems, speedup applications by offloading certain compute operations that can run faster on accelerators. Thus, it is not surprising that many of top500 supercomputers use accelerators. However, in addition to procurement cost, significant programming and porting effort is required to realize the potential benefit of such accelerators...
The performance of parallel scientific applications depends on many factors which are determined by the execution environment and the parallel application. Especially on large parallel systems, it is too expensive to explore the solution space with series of experiments. Deriving analytical models for applications and platforms allow estimating and extrapolating their execution performance, bottlenecks,...
A low-diameter, fast interconnection network is going to be a prerequisite for building exascale machines. A two-level direct network has been proposed by several groups as a scalable design for future machines. IBM's PERCS topology and the dragonfly network discussed in the DARPA exascale hardware study are examples of this design. The presence of multiple levels in this design leads to hot-spots...
In the evaluation process of Military communication network effectiveness (MCNE), the evaluation data mainly come from expert judgments, simulation results and test bed data, and these data cannot be directly used to evaluate MCNE because these three kinds of data are very different in form and in attribute. This research proposed a novel method which synthesizes expert judgments, simulation results,...
In large-scale cluster systems, interconnecting thousands of computing nodes increase the complexity of the network topology. Nevertheless, few existing computational models consider the impact of hierarchical communication latencies and bandwidths caused by the network complexity. In this paper we propose a new parallel computational model called LogGPH with a new parameter H incorporated into the...
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