Chao Qian

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We live in a dynamic visual world where the appearance of scenes changes dramatically from hour to hour or season to season. In this work we study "transient scene attributes" -- high level properties which affect scene appearance, such as "snow", "autumn", "dusk", "fog". We define 40 transient attributes and use crowdsourcing to annotate thousands of(More)
Recombination (or called <i>crossover</i>) operators are a kind of characterizing feature of evolutionary algorithms (EAs). The usefulness of recombination operators has been verified empirically in many practical applications, and has also been theoretically studied in single-objective optimization. For multi-objective optimization, however, there lacks(More)
Running time analysis of metaheuristic search algorithms has attracted a lot of attention. When studying a metaheuristic algorithm over a problem class, a natural question is what are the easiest and the hardest cases of the problem class. The answer can be helpful for simplifying the analysis of an algorithm over a problem class as well as understanding(More)
Recombination (also called crossover) operators are widely used in EAs to generate offspring solutions. Although the usefulness of recombination has been well recognized, theoretical analysis on recombination operators remains a hard problem due to the irregularity of the operators and their complicated interactions to mutation operators. In this paper, as(More)
Ensemble learning is among the state-of-the-art learning techniques, which trains and combines many base learners. Ensemble pruning removes some of the base learners of an ensemble, and has been shown to be able to further improve the generalization performance. However, the two goals of ensemble pruning, i.e., maximizing the generalization performance and(More)
—Evolutionary algorithms are a large family of heuristic optimization algorithms. They are problem independent, and have been applied in various optimization problems. Thus general analysis tools are especially appealing for guiding the analysis of evolutionary algorithms in various situations. This paper develops the switch analysis approach for running(More)
Evolutionary algorithms (EAs), simulating the evolution process of natural species, are used to solve optimization problems. Crossover (also called recombination), originated from simulating the chromosome exchange phenomena in zoogamy reproduction, is widely employed in EAs to generate offspring solutions, of which the effectiveness has been examined(More)
Sampling has been often employed by evolutionary algorithms to cope with noise when solving noisy real-world optimization problems. It can improve the estimation accuracy by averaging over a number of samples, while also increasing the computation cost. Many studies focused on designing efficient sampling methods, and conflicting empirical results have been(More)