共查询到20条相似文献,搜索用时 0 毫秒
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为了去除程序中的简单开关分支结构,提出了一种新的重构方法——"以数组取代类型码"重构手法。将这种新的重构方法用于重构简单工厂模式,就得到了一种新的软件设计模式——"数组工厂"模式。数组工厂模式适用于实例化某个具体类在软件执行流程的任意时刻只存在一个实体的对象;对于软件执行流程中可以同时存在多个实体的具体类对象的实例化工作,通过改造数组工厂模式,提出了"数组原型"模式。数组工厂和数组原型模式是两种结构优良的创建型设计模式,它们免除了简单工厂方法中的开关分支语句,具有优化代码结构、提高程序执行性能等优点,并且完全符合开放—封闭原则。 相似文献
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Self-organizing learning array 总被引:2,自引:0,他引:2
A new machine learning concept-self-organizing learning array (SOLAR)-is presented. It is a sparsely connected, information theory-based learning machine, with a multilayer structure. It has reconfigurable processing units (neurons) and an evolvable system structure, which makes it an adaptive classification system for a variety of machine learning problems. Its multilayer structure can handle complex problems. Based on the entropy estimation, information theory-based learning is performed locally at each neuron. Neural parameters and connections that correspond to minimum entropy are adaptively set for each neuron. By choosing connections for each neuron, the system sets up its wiring and completes its self-organization. SOLAR classifies input data based on the weighted statistical information from all the neurons. The system classification ability has been simulated and experiments were conducted using test-bench data. Results show a very good performance compared to other classification methods. An important advantage of this structure is its scalability to a large system and ease of hardware implementation on regular arrays of cells. 相似文献
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《数码设计:surface》2009,(1):56-57
小说《红字》中海斯特·白兰太太胸前刺眼的红A字,引起无数的警戒,让人退避三舍。红色,从来是警号,是禁忌,是反叛,纠起危险的信号,它所向披靡,又意味着浮想联翩的致命诱惑,赫然让人止步。 相似文献
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Desprez F. Dongarra J. Petitet A. Randriamaro C. Robert Y. 《Parallel and Distributed Systems, IEEE Transactions on》1998,9(2):192-205
This article is devoted to the run-time redistribution of one-dimensional arrays that are distributed in a block-cyclic fashion over a processor grid. While previous studies have concentrated on efficiently generating the communication messages to be exchanged by the processors involved in the redistribution, we focus on the scheduling of those messages: how to organize the message exchanges into “structured” communication steps that minimize contention. We build upon results of Walker and Otto, who solved a particular instance of the problem, and we derive an optimal scheduling for the most general case, namely, moving from a CYCLIC(r) distribution on a P-processor grid to a CYCLIC(s) distribution on a Q-processor grid, for arbitrary values of the redistribution parameters P, Q, r, and s 相似文献
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Initialization of an array, out of which only a small initially unknown portion will eventually be used, is a frequent need in programming. A folklore solution for initializing an array of n entries in constant time uses 2n?log2n? extra bits to realize a stack of back pointers to the actually used entries of the array. Navarro has given a succinct version of this technique, which requires only n + o(n) bits of auxiliary storage. We describe, analyze, and experimentally compare these solutions and their space‐efficient but theoretically suboptimal alternatives based on a simple bitmap for keeping track of the array entries which have been assigned a value. Experimental results suggest that each of the methods has its niche of excellence, which are roughly as follows: the theoretically optimal solutions based on a stack of back pointers perform in general best on sparse arrays, whose access frequency is less than 1% of the number of their entries. Brute‐force initialization of the entire array seems generally to give the best overall performance for dense arrays whose access frequency is over 10% of their size. For the remaining cases of arrays with 1–10% access frequency, the methods which use a simple bitmap appear to give the best performance. The experiments show that the choice of a suitable implementation may yield substantial, up to hundreds of times speed‐ups in the performance of initializable array operations. Copyright © 2015 John Wiley & Sons Ltd. 相似文献
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《Parallel Computing》1986,3(3):217-229
We consider the case of a 2-dimensional wavefront array processor where only one wavefront appears at any time. We show that in such a situation, this 2-dimensional wavefront processor can be mapped to a linear array processor if the wavefronts never backtrack. The mapping will not increase the number of registers in each processor element. Two examples, the spoken words recognition problem and the longest common subsequence problem, are given to demonstrate the feasibility of this method. 相似文献
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Selective substitution array grammars are introduced, which abstract the notions of rewriting rules, direct derivation steps, derivations and rewriting in a sequential or parallel way. These array grammars provide for a unified framework for many of the two-dimensional array grammars in the literature. In addition, they point towards new interpretations resulting in possible new array grammars. 相似文献
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Pyroelectric thin-film sensor array 总被引:5,自引:0,他引:5
M. Kohli C. Wuethrich K. Brooks B. Willing M. Forster P. Muralt N. Setter P. Ryser 《Sensors and actuators. A, Physical》1997,60(1-3):147-153
Pyroelectric thin-film point detectors and 1 × 12 arrays have been fabricated and characterized. They consist of sol-gel-deposited PZT thin-film elements on micromachined Si3N4/SiO2 membranes. The measured current and voltage response as a function of modulation frequency of a 1 × 12 array element is compared with finite-element calculations. Voltage responsivities of almost 3000 V W−1 in vacuum and 800 V W−1 in air have been achieved for 0.4 mm × 0.9 mm elements. Some point detectors have been completely packaged and correct operation in a movement detection system has been demonstrated. 相似文献
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Hybrid multiprocessor architectures which combine re-configurable computing and multiprocessors on a chip are being proposed to transcend the performance of standard multi-core parallel systems. Both fine-grained and coarse-grained parallel algorithm implementations are feasible in such hybrid frameworks. 相似文献
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Vertical comb array microactuators 总被引:5,自引:0,他引:5
A vertical actuator fabricated using a trench-refilled-with-polysilicon (TRiPs) process technology and employing an array of vertical oriented comb electrodes is presented. This actuator structure provides a linear drive to deflection characteristic and a large throw capability which are key features in many sensors, actuators and micromechanisms. The actuation principle and relevant theory is developed, including FastCap simulations for theoretical verification. Design simplifications have been suggested that enable one to use parallel plate analytical expressions which match simulation results with /spl sim/5.6% error. Several actuators were designed and fabricated using the 7-mask TRiPs technology with calculated drive voltages as low as 45 V producing 10 /spl mu/m of deflection. The actuators employed a mechanical structure that was 18 /spl mu/m tall using a polysilicon layer 1.5 /spl mu/m thick and occupying a total area of 750 /spl mu/m by 750 /spl mu/m. The actuators were successfully tested electrostatically and several microns of deflection were observed. 相似文献