752 publications from this institution
Optimization is everywhere, from business transactions and engineering design to planning your holidays and daily travel routes. Business organizations have to maximize their profits and minimize the costs. Engineering design has to maximize the performance of the designed product while minimizing the manufacturing cost at the same time. Even when we plan holidays we want to maximize the enjoyment and minimize the cost. Therefore, the studies of optimization are of both scientific interest and practical implications and subsequently the methodology can potentially have many applications. This chapter introduces all the important concepts concerning optimization and nonlinear programming.
Structural testing is most important and high demand testing technique for code-based criteria in software testing. In structural testing, path testing technique is the most useful technique. In path testing, generation of all independent paths (non redundant) is a complex one. The aim of this paper is to present a simple and efficient algorithm that can automatically generate all possible paths in a Control Flow Graph for Path testing. Cuckoo behaviour is used in this algorithm for extracting optimal paths. This cuckoo search algorithm generates paths equal to the cyclomatic complexity. It can be shown that the proposed approach guarantees full path coverage.
No abstract is provided for this article.
Firefly algorithms (FA) appeared about five years ago, in 2008, and the literature has expanded dramatically with diverse applications. In this chapter, we introduce the standard firefly algorithm, then briefly review the variants, together with a selection of recent publications. We also analyze the characteristics of FA and try to answer the question of why FA is so efficient.
The calibration of sound intensity instruments—in particular, with respect to instruments' sensitivity to both sound intensity and particle velocity in the rated frequency range—is challenging for laboratories worldwide. The commonly used approach is to measure the pressure sensitivity and phase difference of a pair of microphones, and electrically test the analyzer. The intensity instrument cannot be fully calibrated if only the components of the intensity measurement system are calibrated. Ideally, the sound intensity instrument should be calibrated as a system, along with all its parameters being compared with traceability to recognized standards; this will increase the confidence in the validity of measurement results. Currently, calibration below 50 Hz is still not feasible. To meet this requirement, the Beijing Aerospace Institute of Metrology and Measurement Technology has developed a double coupler calibration system capable of generating an intensity or particle velocity level of known amplitude and direction traceable to recognized standards. This paper covers the principle of the double coupler technique, design of the system, and generation of the reference intensity signal. The calibration results are in good agreement with the theoretical calculation results.
This paper investigates the sparse β model with 𝓁1 penalty in the field of network data models, which is a hot topic in both statistical and social network research. We present a refined algorithm designed for parameter estimation in the proposed model. Its effectiveness is highlighted through its alignment with the proximal gradient descent method, stemming from the convexity of the loss function. We study the estimation consistency and establish an optimal bound for the proposed estimator. Empirical validations facilitated through meticulously designed simulation studies corroborate the efficacy of our methodology. These assessments highlight the prospective contributions of our methodology to the advanced field of network data analysis.
Details the interdisciplinary nature of mathematical modeling and numerical algorithms. The book combines a variety of applications from diverse fields to illustrate how the methods can be used to model physical processes, design new products, find solutions to challenging problems, and increase competitiveness in international markets.
Swarm intelligence based algorithms such as particle swarm optimization have become popular in the last two decades. Various new algorithms such as cuckoo search and bat algorithm also show promising efficiency. In all these algorithms, it is essential to maintain the balance of exploration and exploitation by controlling directly and indirectly the diversity of the population. Different algorithms may use different mechanisms to control such diversity. In this review paper, the author reviews and analyzes the roles of diversity and relevant mechanisms in swarm intelligence. The author also discuss parameter tuning and parameter control. In addition, the author highlights some key open questions in swarm intelligence.
No abstract is provided for this article.
No abstract is provided for this article.
Swarm intelligence (SI) and SI-based algorithms have become popular and useful in almost all areas of sciences and engineering. Significant developments have been made in recent years. This paper provides a short but timely analysis about SI algorithms and their links with self-organization. Emphasis has been on the present developments by analyzing the main characteristics and properties of algorithms, while future directions are pointed out by highlighting key challenges and their implications.
Matrices can be considered as an extension of vectors, and matrices form the cornerstone of modern scientific computing and engineering simulations. This chapter introduces matrices and matrix algebra.
Four schemes for binary solutions are proposed in this work to solve the resource allocation problem in an OFDMA system. The binary solution is sought at the early stage before applying the Genetic Algorithm to solve the real-valued problem. Each scheme performed differently in terms of Energy Efficient (EE) values obtained and the required computational cost. Out of four schemes (maxJ, maxP, minP and CP), the best scheme found in this study is CP as this scheme obtained the highest average EE with moderate computational cost.
Bacterial transport in saturated–unsaturated soils is an important process in environmental science and hydrology. A mechanistic model for bacterial transport in geomaterials is presented here. The model equations comprise a pair of fully coupled non‐linear parabolic partial differential equations that describe the concentration of microbes in the liquid water and solid surfaces. The model equations not only describe the bacteria sorption and desorption processes, but also take into account the retention of bacteria at the liquid–water interface and the dynamic reproduction characteristics of the bacteria. The instability and travelling waves for the coupled equations are analysed. Copyright © 2004 John Wiley & Sons, Ltd.
Efficiency of an optimization process is largely determined by the search algorithm and its fundamental characteristics. In a given optimization, a single type of algorithm is used in most applications. In this paper, we will investigate the Eagle Strategy recently developed for global optimization, which uses a two-stage strategy by combing two different algorithms to improve the overall search efficiency. We will discuss this strategy with differential evolution and then evaluate their performance by solving real-world optimization problems such as pressure vessel and speed reducer design. Results suggest that we can reduce the computing effort by a factor of up to 10 in many applications.
This chapter introduces some commonly used optimization techniques, including classical gradient-based methods, gradient-free methods, and the new optimizers for deep learning. It also introduces evolutionary algorithms and nature-inspired algorithms for optimization and computational intelligence.
A mathematical model is presented for pressure interactions with premixed flames in a prescribed strained velocity field. A stability analysis is carried out including pressure disturbances and an approximate frequency condition obtained. For positive strain the unsteady analysis indicates that the pulsating instability is suppressed. However, for a converging flow (negative strain), the instability is encouraged. Furthermore, the change of the neutral stability boundary in parameter space is explored, showing that a sharp pressure reduction makes the pulsating instability much more accessible.
