Signal extraction and knowledge discovery based on statistical modeling

In the coming post IT era, the problems of signal extraction and knowledge discovery from huge data sets will become very important. For these problems, the use of good model is crucial and thus the statistical modeling will play an important role. In this paper, we show two basic tools for statistical modeling, namely the information criteria for the evaluation of the statistical models and generic state-space model which provides us with a very flexible tool for modeling complex and time-varying systems. As examples of these methods we shall show some applications in seismology and macro economics.     

基于微扰突变的蛋白质侧链安装的遗传算法

在侧链转子库的基础上,我们提出了用于蛋白质侧链安装的微扰突变的遗传算法方法。它在常规单点突变的同时又采用了微扰突变的方法,因而同时具有传统遗传算法的和理论搜索模拟方法的特点。我们分别用均方根偏差能量函数和起初的能量函数灵敏计算了单个蛋白质和蛋白与蛋白复合物结合区域的侧链构象。结果表明该方法优于传统的遗传算法,能精确地物理蛋白质侧链的构象。     

Evolutive Introns: A Non-Costly Method of Using Introns in GP

We proposed a new strategy to explicitly define introns that increases the probability of selecting good crossover points as evolution goes on. Our approach differs from existing methods in the procedure followed to adapt the probabilities of groups of code being protected. We also provide some experimental results in symbolic regression and classification that reinforced our belief in the usefulness of this procedure. Collateral effects of Evolutive Introns (EIs) are also studied to determine possible modifications in the behavior of a classical Genetic Programming (GP) system.     

Sexual Selection for Genetic Algorithms

Genetic Algorithms (GA) have been widely used inoperations research andoptimization since first proposed. A typical GAcomprises three stages, the encoding, theselection and the recombination stages. In thiswork, we focus our attention on the selectionstage of GA, and review afew commonly employed selection schemes andtheir associated scalingfunctions. We also examine common problems andsolution methods forsuch selection schemes.We then propose a new selection scheme inspiredby sexual selectionprinciples through female choice selection, andcompare the performance of this new schemewith commonly used selection methods in solvingsome well-known problems including the Royal RoadProblem, the Open Shop Scheduling Problem andthe Job Shop Scheduling Problem.     

基于遗传算法和梯度下降的RBF神经网络组合训练方法

在使用基于梯度下降的径向基函数（RBF）神经网络学习方法时，由于网络目标函数误差曲面极其复杂，因而产生了网络收敛速度慢，且容易陷入局部极小，网络初始值的设置对网络训练结果影响很大等问题。基于遗传算法的训练方法能够摆脱陷入局部最优的困扰，但遗传算法的局部搜索能力不够，从而影响网络的训练效果。为了解决上述问题，在研究两种算法特点的基础上，提出一种组合训练方法，用提出的训练方法对UCI中的部分数据集进行了仿真实验，并将实验结果与传统方法下的结果进行了比较，实验结果表明新方法是有效的。     

(l,d)-模体识别问题的遗传优化算法

转录因子结合位点识别在基因表达调控过程中起着重要的作用.文中提出了一种贝叶斯模型驱动的模体识别的遗传优化算法GOBMD(Genetic Optimization with Bayesian Model for Motif Discovery).GOBMD首先使用一个基于位置加权散列的投影过程,将输入序列中的l-mers投影到k维(k相似文献   

Towards Exploring Large Molecular Space: An Efficient Chemical Genetic Algorithm

Generating molecules with desired properties is an important task in chemistry and pharmacy. An efficient method may have a positive impact on finding drugs to treat diseases like COVID-19. Data mining and artificial intelligence may be good ways to find an efficient method. Recently, both the generative models based on deep learning and the work based on genetic algorithms have made some progress in generating molecules and optimizing the molecule’s properties. However, existing methods have defects in the experimental evaluation standards. These methods also need to be improved in efficiency and performance. To solve these problems, we propose a method named the Chemical Genetic Algorithm for Large Molecular Space (CALM). Specifically, CALM employs a scalable and efficient molecular representation called molecular matrix. And we design corresponding crossover, mutation, and mask operators inspired by domain knowledge and previous studies. We apply our genetic algorithm to several tasks related to molecular property optimization and constraint molecular optimization. The results of these tasks show that our approach outperforms the other state-of-the-art deep learning and genetic algorithm methods, where the z tests performed on the results of several experiments show that our method is more than 99% likely to be significant. At the same time, based on the experimental results, we point out the defects in the experimental evaluation standard which affects the fair evaluation of all previous work. Avoiding these defects helps to objectively evaluate the performance of all work.     

Difference-based firefly programming for symbolic regression problems

Automatic programming is a type of programming that has the ability to analyze and solve problems using the principles of symbolic regression analysis. These methods can solve complex problems regardless of whether they have a specific pattern or not. In this work, we are going to introduce the difference-based firefly programming (DFP) method as an improved version of the standard firefly programming method. We have analyzed the performance of this new improved method, which will be described in detail within the scope of this work. In order to evaluate the performance of the newly presented method, the results have been compared to the results of the standard method and the results of other methods that are used to solve the same type of problems. DFP has been used also in forecasting and modeling a real-world time-series problem, where it showed good performance too. In general, the results demonstrated the improved performance of the newly introduced method and showed its ability to efficiently solve complex problems.     

基于模拟退火算法的遗传程序设计方法

遗传程序设计（GP）是运用遗传算法的思想，通过生成计算机程序来解决问题的，但用它来解决大型或复杂问题时，就存在一些难以解决的问题，尤其是大量使用计算机内存和CPU时间，大大影响了工作性能。以符号回归问题为例，针对传统的遗传程序设计方法在解决问题时所遇到的困难，提出一个基于模拟退火算法的遗传程序设计方法，进一步提高GP系统求解问题的能力。     

改进的基因表达式程序设计实现复杂函数的自动建模

基因表达式程序设计(简称GEP)是一种新型的遗传算法,它继承了遗传程序设计(简称GP)和遗传算法的优点并且具有更高的效率和更强的搜索能力,但同时也存在缺乏学习机制,搜索过于盲目的缺点,针对其缺点对其进行了如下改进:(1)改变了GEP的基因表达式结构,将原来的“头+尾”结构改成了“头+身+尾”结构,以利于其引进学习机制;(2)同源基因也采用“头+身+尾”结构,以利于增强其搜索能力;用其实现复杂函数的自动建模,实例测试的结果表明用改进的基因表达式程序设计得到的模型比传统方法得到的模型要好,甚至优于用遗传程序设计和基本的基因表达式程序设计得到的模型。     

遗传算法的现状及发展动向

遗传算法在许多优化问题中都有成功的应用,但其本身也存在一些不足．如何改善遗 传算法的搜索能力和提高算法的收敛速度,使其更好地解决实际问题,是各国学者一直探索 的主要课题之一．本文综述了遗传算法中编码表示、适应度函数、选择策略、控制参数和遗 传算子等方面的各种改进措施,并给出了遗传算法的发展动向．     

Tackling Real-Coded Genetic Algorithms: Operators and Tools for Behavioural Analysis

Genetic algorithms play a significant role, as search techniques forhandling complex spaces, in many fields such as artificial intelligence, engineering, robotic, etc. Genetic algorithms are based on the underlying genetic process in biological organisms and on the naturalevolution principles of populations. These algorithms process apopulation of chromosomes, which represent search space solutions,with three operations: selection, crossover and mutation.Under its initial formulation, the search space solutions are coded using the binary alphabet. However, the good properties related with these algorithms do not stem from the use of this alphabet; other coding types have been considered for the representation issue, such as real coding, which would seem particularly natural when tackling optimization problems of parameters with variables in continuous domains. In this paper we review the features of real-coded genetic algorithms. Different models of genetic operators and some mechanisms available for studying the behaviour of this type of genetic algorithms are revised and compared.     

Hybrid learning models to get the interpretability–accuracy trade-off in fuzzy modeling

One of the problems associated to linguistic fuzzy modeling is its lack of accuracy when modeling some complex systems. To overcome this problem, many different possibilities of improving the accuracy of linguistic fuzzy modeling have been considered in the specialized literature. We will call these approaches as basic refinement approaches. In this work, we present a short study of how these basic approaches can be combined to obtain new hybrid approaches presenting a better trade-off between interpretability and accuracy. As an example of application of these kinds of systems, we analyze seven hybrid approaches to develop accurate and still interpretable fuzzy rule-based systems, which will be tested considering two real-world problems.This work has been supported by the spanish cicyt project tic2002-04036-c05-01 (keel).     

Operator and parameter adaptation in genetic algorithms

 Genetic Algorithms are a class of powerful, robust search techniques based on genetic inheritance and the Darwinian metaphor of “Natural Selection”. These algorithms maintain a finite memory of individual points on the search landscape known as the “population”. Members of the population are usually represented as strings written over some fixed alphabet, each of which has a scalar value attached to it reflecting its quality or “fitness”. The search may be seen as the iterative application of a number of operators, such as selection, recombination and mutation, to the population with the aim of producing progressively fitter individuals. These operators are usually static, that is to say that their mechanisms, parameters, and probability of application are fixed at the beginning and constant throughout the run of the algorithm. However, there is an increasing body of evidence that not only is there no single choice of operators which is optimal for all problems, but that in fact the optimal choice of operators for a given problem will be time-variant i.e. it will depend on such factors as the degree of convergence of the population. Based on theoretical and practical approaches, a number of authors have proposed methods of adaptively controlling one or more of the operators, usually invoking some kind of “meta-learning” algorithm, in order to try and improve the performance of the Genetic Algorithm as a function optimiser. In this paper we describe the background to these approaches, and suggest a framework for their classification, based on the learning strategy used to control them, and what facets of the algorithm are susceptible to adaptation. We then review a number of significant pieces of work within the context of this setting, and draw some conclusions about the relative merits of various approaches and promising directions for future work.     

Model and methods to address urban road network problems with disruptions

Disruptions in urban road networks can quickly and significantly reduce the quality of the whole transportation network, and impact urban mobility for light vehicles, public transportation, etc. In this study, we consider both unidirectional and multidirectional road network problems with disruptions and connecting requirements. These problems aim at reconfiguring the urban network in terms of road direction in order to maintain a path among all points of the network (strong connectivity). The former is defined on simple graphs, mainly modeling part of a city such as historical centers, while the latter relies on multigraphs, modeling more general networks. Restoring the network (strong connectivity) after some disruptions may require the modification of the orientation of some streets, that is, arc reversals. Such actions can disturb users' driving habits. Thus, two objectives are considered separately: minimizing the total travel distance and minimizing the number of arc reversals. We define formally both problems and propose two metaheuristics, a biased random key genetic algorithm and an iterated local search. Numerical experiments have been performed on a set of generated instances and on the urban network of Troyes (France).     

基于多层感知遗传算法的图象分割新方法

本文提出了一种新的灰度图象分割方法．该方法模拟了人类视觉由粗到细的分割过程，针对图象中各位置的不同内容采用不同的细节分辨率，形成多层感知的塔式结构；而在每一分辨率层上，采用小生境的遗传算法进行图象分割，使整个算法具有较强的鲁棒性、适用性、非监督性及高度的并行性，通过与单层遗传分割算法［1］相对比，显示了该方法具有更好的分割效果．     

Iterative MILP methods for vehicle-control problems

Mixed-integer linear programming (MILP) is a powerful tool for planning and control problems because of its modeling capability and the availability of good solvers. However, for large models, MILP methods suffer computationally. In this paper, we present iterative MILP algorithms that address this issue. We consider trajectory-generation problems with obstacle-avoidance requirements and minimum-time trajectory-generation problems. These problems involve vehicles that are described by mixed logical dynamical equations, a form of hybrid system. The algorithms use fewer binary variables than standard MILP methods, and require less computational effort.     

Application of artificial neural network models to linear and nonlinear RF circuit modeling

Typical RF and wireless circuits comprise a large number of linear and nonlinear components. The complexity of the RF portion of a wireless system continues to increase in order to support multiple standards, multiple frequency bands, the need for higher bandwidth, and stringent adjacent channel specifications. The time required to carry out a virtual prototyping of such complex circuits and their trade‐off analysis with the baseband circuitry can be unacceptably long, because both the circuit simulation and optimization procedures can be very time consuming. Typically, one divides the task into those of designing the nonlinear elements or subcircuits that can be accurately analyzed by using RF simulators, and uses circuit level analysis for simulating the circuits at module level. In this article, we will review some approaches to modeling both the linear RF elements as well as nonlinear subcircuits (amplifiers, mixers, VCOs), and will emphasize on the application of the artificial neural networks (ANNs). Furthermore, we will demonstrate the use of the ANN to the design of RF circuits and illustrate their application to wireless types of problems of practical interest. © 2001 John Wiley & Sons, Inc. Int J RF and Microwave CAE 11: 231–247, 2001.     

改进量子遗传算法用于多峰值函数优化

传统遗传算法（SGA）在处理多峰值函数优化问题中存在局部收敛性的问题,最初的量子遗传算法（QGA）也存在这一问题。运用一种改进量子遗传算法（MQGA）,有效地解决了一些多峰值函数的优化问题。根据几个重要的测试函数进行仿真实验结果证明,与SGA和QGA相比,改进的量子遗传算法（MQGA）在一些多峰值优化问题中更具有效性和可行性。     

遗传算法的编码理论与应用

编码是遗传算法求解问题的前提,文章分析了二进制编码、格雷码编码、实数编码、符号编码、排列编码、二倍体编码、DNA编码、混合编码、二维染色体编码或矩阵编码等编码的实质内容,在树编码和可变长编码基础上阐述了自适应编码的基本理论,提出了基于相似度的可变长编码和基于结构的agent编码方式,给出了函数优化、TSP、KP、JSP、机器人路径规划、图的划分和倒立摆等典型优化问题的编码方案。