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151.
152.
153.
Source number estimation and separation algorithms of underdetermined blind separation 总被引:2,自引:0,他引:2
YANG ZuYuan TAN BeiHai ZHOU GuoXu ZHANG JinLong 《中国科学F辑(英文版)》2008,(10):1623-1632
Recently, sparse component analysis (SCA) has become a hot spot in BSS research. Instead of independent component analysis (ICA), SCA can be used to solve underdetermined mixture efficiently. Two-step approach (TSA) is one of the typical methods to solve SCA based BSS problems. It estimates the mixing matrix before the separation of the sources. K-means clustering is often used to estimate the mixing matrix. It relies on the prior knowledge of the source number strongly. However, the estimation of the source number is an obstacle. In this paper, a fuzzy clustering method is proposed to estimate the source number and mixing matrix simultaneously. After that, the sources are recovered by the shortest path method (SPM). Simulations show the availability and robustness of the proposed method. 相似文献
154.
非均匀抽样网格简化 总被引:2,自引:0,他引:2
提出了一种考虑视点空间中某些重要视点的非均匀抽样网格简化的新方法,是在借鉴了Garland-Heckbert方法的基础上提出的,是一种考虑外观相似性的简化算法。给出并证明了两个判定边界的定理,为抽样提供了理论依据。在简化过程中,该算法通过采用视点空间中某些重要视点对模型进行抽样,使抽中的顶点对(轮廓附近的顶点对)得到适当保护。该算法除具有Garland-Heckbert方法的长处外,还可以在三角面片数较少的情况下(50多个三角面片),尽可能保持模型的重要外观特征,给出了计算0-1图像的外观相似性误差的公式,通过该公式对简化结果进行比较,证明提出的简化算法对保持模型的外观特征是行之有效的。最后对该算法的时间和空间复杂性进行了分析。 相似文献
155.
供应链集成化模型与优化 总被引:2,自引:0,他引:2
本文建立了一个包括供应商、制造商、销售商
在内的集成化模型,这一模型含有线性状态方程和神经网络非线性模型,提出了库存成本、
供应成本、生产水平等在内的供应链目标函数和约束条件.对于供应链集成化模型采用模拟
退火方法进行优化,并以辽化公司为背景进行了初步条件的仿真工作. 相似文献
156.
157.
Pradeep K. Nalla Roland J. Weiss Prakash Peranandam Jürgen Ruf Thomas Kropf Wolfgang Rosenstiel 《Electronic Notes in Theoretical Computer Science》2006,135(2):47
In this paper we describe an algorithm for distributed, BDD-based bounded property checking and its implementation in the verification tool SymC. The distributed algorithm verifies larger models and returns results faster than the sequential version.The core algorithm distributes partitions of the state set to computation nodes after reaching a threshold size. The nodes proceed with image computation on the nodes asynchronously. The main scalability problem of this scheme is the overlap of state set partitions. We present static and dynamic overlap reduction techniques. 相似文献
158.
Recently, High Performance Computing (HPC) platforms have been employed to realize many computationally demanding applications
in signal and image processing. These applications require real-time performance constraints to be met. These constraints
include latency as well as throughput. In order to meet these performance requirements, efficient parallel algorithms are
needed. These algorithms must be engineered to exploit the computational characteristics of such applications.
In this paper we present a methodology for mapping a class of adaptive signal processing applications onto HPC platforms
such that the throughput performance is optimized. We first define a new task model using the salient computational characteristics
of a class of adaptive signal processing applications. Based on this task model, we propose a new execution model. In the
earlier linear pipelined execution model, the task mapping choices were restricted. The new model permits flexible task mapping
choices, leading to improved throughput performance compared with the previous model. Using the new model, a three-step task
mapping methodology is developed. It consists of (1) a data remapping step, (2) a coarse resource allocation step, and (3)
a fine performance tuning step. The methodology is demonstrated by designing parallel algorithms for modern radar and sonar
signal processing applications. These are implemented on IBM SP2 and Cray T3E, state-of-the-art HPC platforms, to show the
effectiveness of our approach. Experimental results show significant performance improvement over those obtained by previous
approaches. Our code is written using C and the Message Passing Interface (MPI). Thus, it is portable across various HPC platforms.
Received April 8, 1998; revised February 2, 1999. 相似文献
160.
Clive A J Fletcher 《Sadhana》1993,18(3-4):657-681
A turbulent gas particle finite-volume flow simulation of a representative coal classifier is presented. Typical values of
the loading ratio permit a one-way coupling analysis. As a case study, the computational fluid dynamics code,ranstad, and the modelling aspects are discussed in some detail. The simulation indicates that small (≈ 30 μm) coal particles pass
through the classifier to the furnace but that large (≈ 300 μm) particles are captured and remilled. The computational simulation
indicates that the classifier performance can be improved by internal geometric modification.
The commitment of the Electricity Commission of New South Wales (Pacific Power) to the exploitation of Computational Engineering
for the improvement of all aspects of electricity generation is acknowledged. 相似文献