Self-adaptive differential evolution algorithm using population size reduction and three strategies

Many real-world optimization problems are large-scale in nature. In order to solve these problems, an optimization algorithm is required that is able to apply a global search regardless of the problems’ particularities. This paper proposes a self-adaptive differential evolution algorithm, called jDElscop, for solving large-scale optimization problems with continuous variables. The proposed algorithm employs three strategies and a population size reduction mechanism. The performance of the jDElscop algorithm is evaluated on a set of benchmark problems provided for the Special Issue on the Scalability of Evolutionary Algorithms and other Metaheuristics for Large Scale Continuous Optimization Problems. Non-parametric statistical procedures were performed for multiple comparisons between the proposed algorithm and three well-known algorithms from literature. The results show that the jDElscop algorithm can deal with large-scale continuous optimization effectively. It also behaves significantly better than other three algorithms used in the comparison, in most cases.     

Modified firefly algorithm using quaternion representation

Quaternions are a number system, which extends complex numbers. They are especially useful in areas where fast rotation calculations are needed, e.g., programming video games or controllers of spacecraft. This paper proposes to use quaternion for the representation of individuals in firefly algorithm so as to enhance the performance of the firefly algorithm and to avoid any stagnation. The preliminary results of our experiments after optimizing a test-suite consisting of ten standard functions, showed that the proposed firefly algorithms using quaternion’s representation improved the results of the original firefly algorithm.     

Differential evolution and differential ant-stigmergy on dynamic optimisation problems

Many real-world optimisation problems are of dynamic nature, requiring an optimisation algorithm which is able to continuously track a changing optimum over time. To achieve this, we propose two population-based algorithms for solving dynamic optimisation problems (DOPs) with continuous variables: the self-adaptive differential evolution algorithm (jDE) and the differential ant-stigmergy algorithm (DASA). The performances of the jDE and the DASA are evaluated on the set of well-known benchmark problems provided for the special session on Evolutionary Computation in Dynamic and Uncertain Environments. We analyse the results for five algorithms presented by using the non-parametric statistical test procedure. The two proposed algorithms show a consistently superior performance over other recently proposed methods. The results show that both algorithms are appropriate candidates for DOPs.     

Zero—a blend of static typing and dynamic metaprogramming

Zero is an experimental statically typed, fully object-oriented reflective programming language. Reflective features cover introspection as well as structural and behavioural reflection. The reflective facilities include safe method and class replacements and detailed modification of methods. These enable Zero programs to quickly accommodate to run-time requirements. Behavioural reflection is realised using handlers (hooks), which may be attached to all language constructs based on closures. Zero provides an efficient static typing system with run-time extensions. Methods are first class values and are represented as objects when such representation is required. By using such representation, Zero provides elegant use of statically typed higher-order methods.     

Spectrum of coronary arterial spasm. Clinical, angiographic and myocardial metabolic experience in 29 cases

A relationship of coronary arterial spasm to variant angina pectoris, subendocardial ischemia, major ventricular arrhythmias and myocardial infarction has been demonstrated. In 29 patients, spasm was angiographically observed in normal-appearing coronary arteries (7 patients) as well as superimposed on various degrees of coronary atherosclerotic obstruction (22 patients). All patients experienced an atypical anginal syndrome;16 patients also experienced typical exertional angina. Coronary spasm appeared to be a major contributory factor in eight occurrences of myocardial infarction and in 11 incidents of ventricular tachycardia, ventricular fibrillation and heart block. Coronary spasm in the 29 cases was distributed in the following fashion: left main trunk, 6 cases; right main trunk, 12 cases; proximal left anterior descending artery, 13 cases; proximal circumflex artery, 1 case; distal left anterior descending artery, 1 case; and distal circumflex artery, 2 cases. In 5 cases coronary spasm was noted at multiple sites.     

Fabrication and performance of MMW and SMMW platelet horn arrays

Future spaceborne millimeter and sub-millimeter wave sensing systems will require the sensitivity and resolution only achievable with large focal plane array receiving systems. A technique has been developed for the low cost fabrication of large arrays of millimeter and sub-millimeter wave corrugated feed horns. These arrayed horns exhibit high efficiency and symmetrical receiving patterns and are compatible with integrated receivers. W-band test results of a 3×3 array are presented.     

Design and implementation of domain-specific language easytime

Measuring time in mass sporting competitions is, typically, performed with a timing system that consists of a measuring technology and a computer system. The first is dedicated to tracking events that are triggered by competitors and registered by measuring devices (primarily based on RFID technology). The latter enables the processing of these events. In this paper, the processing of events is performed by an agent that is controlled by the domain-specific language, EasyTime. EasyTime improves the flexibility of the timing system because it supports the measuring of time in various sporting competitions, their quick adaptation to the demands of new sporting competitions and a reduction in the number of measuring devices. Essentially, we are focused on the development of a domain specific language. In practice, we made two case studies of using EasyTime by measuring time in two different sporting competitions. The use of EasyTime showed that it can be useful for sports clubs and competition organizers by aiding in the results of smaller sporting competitions, while in larger sporting competitions it could simplify the configuration of the timing system.     

Performance comparison of self-adaptive and adaptive differential evolution algorithms

Differential evolution (DE) has been shown to be a simple, yet powerful, evolutionary algorithm for global optimization for many real problems. Adaptation, especially self-adaptation, has been found to be highly beneficial for adjusting control parameters, especially when done without any user interaction. This paper presents differential evolution algorithms, which use different adaptive or self-adaptive mechanisms applied to the control parameters. Detailed performance comparisons of these algorithms on the benchmark functions are outlined.     

History mechanism supported differential evolution for chess evaluation function tuning

This paper presents a differential evolution (DE) based approach to chess evaluation function tuning. DE with opposition-based optimization is employed and upgraded with a history mechanism to improve the evaluation of individuals and the tuning process. The general idea is based on individual evaluations according to played games through several generations and different environments. We introduce a new history mechanism which uses an auxiliary population containing good individuals. This new mechanism ensures that good individuals remain within the evolutionary process, even though they died several generations back and later can be brought back into the evolutionary process. In such a manner the evaluation of individuals is improved and consequently the whole tuning process.