14993944
Problem difficulty analysis for particle swarm optimization: deception and modality
This paper studies the problem difficulty for a popular optimization method - particle swarm optimization (PSO), particularly for the PSO variant PSO-cf (PSO with constriction factor), and analyzes its predictive measures. Some previous measures and related issues about other optimizers, mainly including deception and modality, are checked for PSO. It is observed that deception is mainly the combination of three factors - the measure ratios of attraction basins, the relative distance of attractors and the relative difference of attractors' altitudes. Multimodality and multi-funnel are proved not to be the essential factors contributing to the problem difficulty for PSO. The counterexamples and comparative experiments in this paper can be taken as a reference for further researches on novel comprehensive predictive measures of problem difficulty for PSO.
3020798
Statistical learning makes the hybridization of particle swarm and differential evolution more efficient—A novel hybrid optimizer
This brief paper reports a hybrid algorithm we developed recently to solve the global optimization problems of multimodal functions, by combining the advantages of two powerful population-based metaheuristics—differential evolution (DE) and particle swarm optimization (PSO). In the hybrid denoted by DEPSO, each individual in one generation chooses its evolution method, DE or PSO, in a statistical learning way. The choice depends on the relative success ratio of the two methods in a previous learning period. The proposed DEPSO is compared with its PSO and DE parents, two advanced DE variants one of which is suggested by the originators of DE, two advanced PSO variants one of which is acknowledged as a recent standard by PSO community, and also a previous DEPSO. Benchmark tests demonstrate that the DEPSO is more competent for the global optimization of multimodal functions due to its high optimization quality.
18783473
A multi-objective-based non-stationary UAV assignment model for constraints handling using PSO
An unmanned aerial vehicle (UAV) assignment requires allocating vehicles to destinations to complete various jobs. It is a complex assignment problem with hard constraints, and potential dimensional explosion when the scenarios become more complicated and the size of problems increases. Moreover, the non-stationary UAV assignment problem, studied in the paper, is more difficult, since dynamic scenarios are introduced, e.g. change of the number, or different task requirements of targets and vehicle, etc. In this paper, a "Constraint-First-Objective- Next" model is proposed for the non-stationary problem. The proposed model can effectively handle constraints as an additional objective, including constraints expressed by nature language, and is flexible enough to be combined with kinds of intelligent computation algorithms. A local version of PSO is cooperated with the proposed model to solve non-stationary UAV assignment problems. Numerical experimental results illustrate that it can efficiently achieve the optima and demonstrate the effectiveness.
2085735
A router based unequal error control scheme for video over the Internet
This paper presents a router based unequal error protection scheme for video over the Internet. The proposed scheme classifies the whole bitstream into two priorities according to their importance and packetizes them into packets with two priorities. To reduce the loss ratio of video packets with higher priority, an active queue management scheme is designed at each router to provide more chance for these packets to transmit over the Internet. Compared to an end-to-end based approach, in which some redundancy packets are generated to protect the packets with higher priority, our proposed scheme utilizes the whole bandwidth for the source coding. Therefore, the final picture quality is improved.
10141936
Complexity-based rate distortion optimization with perceptual tuning for scalable video coding
This paper has proposed a content adaptive rate-distortion optimization scheme for scalable video coding. To adaptively determine the tradeoff between texture and motion coding, the scheme first makes use of spatial and temporal complexities to adjust the Lagrangian multiplier for all the macroblocks in a frame. After that, the Lagrangian multiplier for every macroblock of the frame is further refined using local perceptual cues. To ensure optimal local selection of the Lagrangian multiplier, several characteristics of human visual system have been taken into account to guide the adjustment. Experiments have shown that the proposed scheme could effectively adapt the adjustment of Lagrangian multiplier to video contents and the subjective quality of the reconstructed frames could be improved without compromising PSNR.
16672435
Modeling and Learning Vague Event Durations for Temporal Reasoning
This paper reports on our recent work on modeling and automatically extracting vague, implicit event durations from text (Pan et al., 2006a, 2006b). It is a kind of commonsense knowledge that can have a substantial impact on temporal reasoning problems. We have also proposed a method of using normal distributions to model Judgments that are intervals on a scale and measure their interannotator agreement; this should extend from time to other kinds of vague but substantive information in text and commonsense reasoning.
23103906
Modeling of Fermentation Process Based on QDPSO-SVM
Utilizing the ability simple in application and quick in convergence of quantum delta-potential-well-based particle swarm optimization (QDPSO) algorithm and the high generalization ability of support vector machine (SVM), selecting the appropriate state variables, a dynamic time-varying model has been built. Using the model and algorithm to per-estimate some biochemical state variables which can not be measured on-line, and to optimise some operational variables. It is proved that the method is efficiency through the practical application of penicillin fermentation process.
2696556
Dynamic Modeling of Biotechnical Process Based on Online Support Vector Machine
Due to the complexity and high non-linearity of biotechnical process, most simple mathematical models cannot describe the behavior of biochemistry systems very well. Therefore, dynamic modeling of biotechnical process is indispensable. Support vector machine (SVM) is a novel machine learning method, which is powerful for the problem characterized by small sample, non-linearity, high dimension and local minima, and has high generalization. But currently most support vector machine regression (SVR) training algorithms are offline, which could not be suit for time-variant system. So an improved SVM called online support vector machine was presented to modeling for the dynamic feature of fermentation process. The model based on the modified SVM was developed and demonstrated using simulation experiments. Some models based on SVM were also presented. The result shows that the modeling based online SVM is superior to modeling based on SVW.