Topic
Transfer function
About: Transfer function is a research topic. Over the lifetime, 14362 publications have been published within this topic receiving 214983 citations. The topic is also known as: system function & network function.
Papers published on a yearly basis
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TL;DR: Experimental results confirm the efficiency of the proposed approach in improving the classification accuracy compared to other meta-heuristic algorithms, and the superiority of X-shaped transfer function over commonly used S-shaped and V- shaped transfer functions.
Abstract: Definitive optimization algorithms are not able to solve high dimensional optimization problems when the search space grows exponentially with the problem size, and an exhaustive search also becomes impractical. To encounter this problem, researchers use approximation algorithms. A category of approximation algorithms is meta-heuristic algorithms which have shown an acceptable degree of efficiency to solve this kind of problems. Social Mimic Optimization (SMO) algorithm is a recently proposed meta-heuristic algorithm which is used to optimize problems with continuous solution space. It is proposed by following the behavior of people in society. SMO can efficiently explore the solution space for obtaining optimal or near-optimal solution by minimizing a given fitness function. Feature selection is a binary optimization problem where the aim is to maximize the classification accuracy of a learning algorithm using minimum the number of features. To convert the continuous search space to a binary one, a proper transfer function is required. The effect a transfer function has on the binary variant of an optimization algorithm is very important since selecting a particular subset of features based on the solution values attained by the algorithm in continuous search space depends on the considered transfer function. To this end, we have proposed a new transfer function, namely X-shaped transfer function, to enhance the exploration and exploitation ability of binary SMO. The proposed X-shaped transfer function utilizes two components and crossover operation to obtain a new solution. Effect of the proposed X-shaped transfer function is compared with the effect of four S-shaped and four V-shaped transfer functions on SMO in terms of achieved classification accuracy, rate of convergence, and number of features selected over 18 standard UCI datasets. The proposed algorithm is also compared with state-of-the-art meta-heuristic feature selection (FS) algorithms. Experimental results confirm the efficiency of the proposed approach in improving the classification accuracy compared to other meta-heuristic algorithms, and the superiority of X-shaped transfer function over commonly used S-shaped and V-shaped transfer functions. The source code of the proposed method along with the datasets used can be found at https://github.com/Rangerix/SocialMimic .
47 citations
01 Jan 1974
TL;DR: In this article, a technique for identifying the modal properties of an elastic structure in a testing laboratory is presented, which is based upon the use of digital processing and the fast Fourier transform (FFT) to obtain transfer function data, and then use of a least squared error estimator t o identify modality properties from the transfer function.
Abstract: A technique for identifying the modal properties of an elastic structure in a testing laboratory is presented. The technique is based upon the use of digital processing and the fast Fourier transform (FFT) to obtain transfer function data, and then the use of a least squared error estimator t o identify modal properties from the transfer function data. Both analytical and experimental results are presented.
47 citations
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TL;DR: The Wiener-Lee-Schetzen method for the identification of a nonlinear system through white gaussian noise stimulation was applied to the transient light growth response of the sporangiophore of Phycomyces, finding that the slow dynamics of the system are of at least fifth order.
47 citations
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TL;DR: This paper has generated a model of a 200-W Doherty amplifier from measured IQ data taken using a wideband code-division multiple-access excitation; the amplifier was driven from the linear regime into saturation.
Abstract: In this paper, we present an envelope-domain behavioral model of a high-power RF amplifier. In this modeling approach, we use the signal envelope information, and the behavioral model is generated using an established nonlinear time-series approach to create a time-domain model that operates in the envelope or signal domain. We have generated a model of a 200-W Doherty amplifier from measured IQ data taken using a wideband code-division multiple-access excitation; the amplifier was driven from the linear regime into saturation. The time-series model was created using a time-delay embedding identified from auto-mutual information analysis, and an artificial neural network was used to fit the multivariate transfer function. The model has been validated using measured and simulated data, and it has been used in the development of a system-level design of a digital pre-distorter
47 citations
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10 Jul 1980TL;DR: In this article, the phase and frequency comparator is used to eliminate non-linearities which would otherwise be inherent in its transfer function and thereby degrade performance of phase-locked systems employing the comparator.
Abstract: A digital phase and frequency detector is capable of providing a linearized transfer function. The digital phase and frequency detector includes two latches each receiving an input and each providing an output. The output of the latches is combined by a logic gate to generate a reset signal. The linearization is a result of providing a delay to the reset signal. The reset signal is used to reset the two latches within the phase and frequency comparator. This improved phase and frequency comparator eliminates non-linearities which would otherwise be inherent in its transfer function and thereby degrade performance of phase-locked systems employing the comparator. The phase and frequency detector is easily manufactured as an integrated circuit and does not require any external signals in order to eliminate the non-linear region.
47 citations