We investigate schemes to accelerate the decay of aircraft trailing vortices. These structures are susceptible to several instabilities that lead to their eventual destruction. We employ an Evolution Strategy to desig...
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ISBN:
(纸本)9783642193279
We investigate schemes to accelerate the decay of aircraft trailing vortices. These structures are susceptible to several instabilities that lead to their eventual destruction. We employ an Evolution Strategy to design a lift distribution and a lift perturbation scheme that minimize the wake hazard as proposed in [6]. The performance of a scheme is measured as the reduction of the mean rolling moment that would be induced on a following aircraft;it is computed by means of a Direct Numerical Simulation using a parallel vortex particle code. We find a configuration and a perturbation scheme characterized by an intermediate wavelength lambda similar to 4.64, necessary to trigger medium wavelength instabilities between tail and flap vortices and subsequently amplify long wavelength modes.
The reliable and fault tolerant computers are key to the success to aerospace, and communication industries. Designing a reliable digital system, and detecting and repairing the faults are challenging tasks in order f...
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ISBN:
(纸本)9780769536422
The reliable and fault tolerant computers are key to the success to aerospace, and communication industries. Designing a reliable digital system, and detecting and repairing the faults are challenging tasks in order for the digital system to operate without failures for a given period of time. The paper presents a new and systematic software engineering approach of performing fault diagnosis parallel and distributed computing. The purpose of the paper would be to demonstrate a method to build a fault diagnosis for a parallel and distributed computing. The paper chooses a model posed a tremendous challenge to the user for fault analysis. The model is the classic PMC model that happens to be a parallel and distributed computing. The paper would also show a method for building an optimal inference engine by obtaining sub graphs that also preserve the necessary and sufficient conditions of the model. Coin words: parallel and distributed computing, Artificial Intelligence
We propose a distributed local search (DLS) algorithm, which is a parallel formulation of a local search procedure in an attempt to follow the spirit of standard local search metaheuristics. Applications of different ...
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ISBN:
(纸本)9783319503073;9783319503066
We propose a distributed local search (DLS) algorithm, which is a parallel formulation of a local search procedure in an attempt to follow the spirit of standard local search metaheuristics. Applications of different operators for solution diversification are possible in a similar way to variable neighborhood search. We formulate a general energy function to be equivalent to elastic image matching problems. A specific example application is stereo matching. Experimental results show that the GPU implementation of DLS seems to be the only method that provides an increasing acceleration factor as the instance size augments, among eight tested energy minimization algorithms.
We investigate constructive interference (CI)-based symbol-level precoding (SLP) in large-scale systems with massive connectivity of users to minimize the transmit power subject to the instantaneous signal-to-interfer...
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ISBN:
(纸本)9798350311143
We investigate constructive interference (CI)-based symbol-level precoding (SLP) in large-scale systems with massive connectivity of users to minimize the transmit power subject to the instantaneous signal-to-interference-plus-noise-ratio (SINR) and CI constraints. By converting the considered problem into a novel separable formulation, we reveal the existence of separability in SLP, which is therefore well-suited for decomposition. The proximal Jacobian alternating direction method of multipliers (PJ-ADMM) framework is adopted to decompose the reformulated problem into multiple subproblems, which can be solved in parallel with closed-form solutions. We further linearize the second-order terms by approximation, which leads to a parallelizable first-order fast solution to SLP. Our derivations are validated by simulation results, which also show that our algorithm can provide optimal performance with substantially lower computational complexity than state-of-the-art algorithms.
The ubiquity of multicore processors, cloud computing, and hardware accelerators have elevated parallel and distributed computing (PDC) topics into fundamental building blocks of the undergraduate CS curriculum. There...
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ISBN:
(纸本)9781665497473
The ubiquity of multicore processors, cloud computing, and hardware accelerators have elevated parallel and distributed computing (PDC) topics into fundamental building blocks of the undergraduate CS curriculum. Therefore, it is increasingly important for students to learn a common core of introductory PDC topics and develop parallel thinking skills early in their CS studies. We present the curricular design, pedagogy, and goals of an introductory-level course on computer systems that introduces parallelcomputing to students who have only a CS1 background. Our course focuses on three curricular goals that serve to integrate the ACM-IEEE TCPP guidelines throughout: a vertical slice through the computer of how it runs a program;evaluating system costs associated with running a program;and taking advantage of the power of parallelcomputing. We elaborate on the goals and details of our course's key modules, and we discuss our pedagogical approach that includes active-learning techniques. We find that the PDC foundation gained through early exposure in this course helps students gain confidence in their ability to expand and apply their understanding of PDC concepts throughout their CS education.
parallel netCDF supports parallel I/O operations for a view of data as a collection of self-describing, portable, and array-oriented objects that can be accessed through a simple interface. Its parallel I/O operations...
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ISBN:
(纸本)9783540928584
parallel netCDF supports parallel I/O operations for a view of data as a collection of self-describing, portable, and array-oriented objects that can be accessed through a simple interface. Its parallel I/O operations are realized with the help of an MPI-I/O library. However, Such the operations are not available in remote I/O operations. So, a remote I/O mechanism of a Stampi library was introduced in an MPI layer of the parallel netCDF to realize such the operations. This system was evaluated on two interconnected PC clusters, and sufficient performance was achieved with a huge amount of data.
We study the numerical behavior of heterogeneous systems such as CPU with CPU or IBM Cell processors for some orthogonalization processes. We focus on the influence of the different floating arithmetic handling of the...
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ISBN:
(纸本)9783642193279
We study the numerical behavior of heterogeneous systems such as CPU with CPU or IBM Cell processors for some orthogonalization processes. We focus on the influence of the different floating arithmetic handling of these accelerators with Gram-Schmidt orthogonalization using single and double precision. We observe for dense matrices a loss of at worst 1 digit for CUDA-enabled GPUs as well as a speed-up of 20x, and 2 digits for the Cell processor for a 7x speed-up. For sparse matrices, the result between CPU and CPU is very close and the speed-up is 10x. We conclude that the Cell processor is a good accelerator for double precision because of its full IEEE compliance, and not sufficient for single precision applications. The CPU speed-up is better than Cell and the decent IEEE support delivers results close to the CPU ones for both precisions.
In this paper, a coupling strategy of the Parareal algorithm with the Waveform Relaxation method is presented for the parallel solution of differential algebraic equations. The classical Waveform Relaxation (in space)...
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ISBN:
(纸本)9780769544151
In this paper, a coupling strategy of the Parareal algorithm with the Waveform Relaxation method is presented for the parallel solution of differential algebraic equations. The classical Waveform Relaxation (in space) method and the Parareal (in time) method are first recalled, followed by the introduction of a coupled Parareal-Waveform Relaxation method recently introduced for the solution of partial differential equations. Here, this coupled method is extended to the solution of differential algebraic equations. Numerical experiments, performed on parallel multicores architectures, illustrate the impressive performances of this new method.
The Deep Stacking Network (DSN) is a special type of deep architecture developed to enable and benefit from parallel learning of its model parameters on large CPU clusters. As a prospective key component of future spe...
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ISBN:
(纸本)9781622767595
The Deep Stacking Network (DSN) is a special type of deep architecture developed to enable and benefit from parallel learning of its model parameters on large CPU clusters. As a prospective key component of future speech recognizers, the architectural design of the DSN and its parallel training endow the DSN with scalability over a vast amount of training data. In this paper, we present our first parallel implementation of the DSN training algorithm. Particularly, we show the tradeoff between the time/memory saving via training parallelism and the associated cost arising from inter-CPU communication. Further, in phone classification experiments, we demonstrate a significantly lowered error rate using parallel full-batch training distributed over a CPU cluster, compared with sequential mini-batch training implemented in a single CPU machine under otherwise identical experimental conditions and as exploited prior to the work reported in this paper.
The aim of this paper is to present a new distributedcomputing middleware for High Performance computing (HPC) based cloud micro-services. The great challenge is to maintain the scalability and efficiency of massivel...
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ISBN:
(纸本)9781509051465
The aim of this paper is to present a new distributedcomputing middleware for High Performance computing (HPC) based cloud micro-services. The great challenge is to maintain the scalability and efficiency of massively parallel and distributed computational system when the intensive big data processed by its applications is widely increased. Besides, the proposed middleware implements a new cooperative micro-services team works model for massively parallel and distributed computing. This model is constituted by distributed micro-services as Micro-service Virtual Processing Units (MsVPUs) with integrated load balancing service and an AMQP communication protocol that grant HPC. The paper shows the proposed distributed computational scheme and its integrated middleware accompanying by some experimental results.
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