Dual sub-swarm interaction QPSO algorithm based on different correlation coefficients

A novel quantum-behaved particle swarm optimization (QPSO) algorithm, the dual sub-swarm interaction QPSO algorithm based on different correlation coefficients (DCC-QPSO), is proposed by constructing master-slave sub-swarms with different potential well centres. In the novel algorithm, the master sub-swarm and the slave sub-swarm have different functinons during the evolutionary process through separate information processing strategies. The master subswarm is conducive to maintaining population diversity and enhancing the global search ability of particles. The slave sub-swarm accelerates the convergence rate and strengthens the particles’ local searching ability. With the critical information contained in the search space and results of the basic QPSO algorithm, this new algorithm avoids the rapid disappearance of swarm diversity and enhances searching ability through collaboration between sub-swarms. Experimental results on six test functions show that DCC-QPSO outperforms the traditional QPSO algorithm regarding optimization of multimodal functions, with enhancement in both convergence speed and precision

Overseas Tourist Movement Patterns in Beijing: The Impact of the Olympic Games

Tourist movement patterns are essential for tourism planners to make decisions on tourism product development, destination planning and marketing. The 2008 Beijing Olympic Games have a great impact on the tourism industry in Beijing, especially on tourism flows and movements. In order to understanding changes of tourist movement patterns during the Games, the paper used content analysis method to analyze 500 trip diaries gathered from 6 different websites from January 2001 to April 2009. The paper also utilized social network analysis software Ucinet 6 and NetDraw to map itineraries and analyze overseas tourist movement patterns in Beijing. As a result, the paper summarized the changes of main tourism attractions and main tourist movement patterns in Beijing during the Olympic periods

A Comprehensive Empirical Investigation on Failure Clustering in Parallel Debugging

The clustering technique has attracted a lot of attention as a promising strategy for parallel debugging in multi-fault scenarios, this heuristic approach (i.e., failure indexing or fault isolation) enables developers to perform multiple debugging tasks simultaneously through dividing failed test cases into several disjoint groups. When using statement ranking representation to model failures for better clustering, several factors influence clustering effectiveness, including the risk evaluation formula (REF), the number of faults (NOF), the fault type (FT), and the number of successful test cases paired with one individual failed test case (NSP1F). In this paper, we present the first comprehensive empirical study of how these four factors influence clustering effectiveness. We conduct extensive controlled experiments on 1060 faulty versions of 228 simulated faults and 141 real faults, and the results reveal that: 1) GP19 is highly competitive across all REFs, 2) clustering effectiveness decreases as NOF increases, 3) higher clustering effectiveness is easier to achieve when a program contains only predicate faults, and 4) clustering effectiveness remains when the scale of NSP1F is reduced to 20%

Direct measurement of the Raman enhancement factor of rhodamine 6G on graphene under resonant excitation

Graphene substrates have recently been found to generate Raman enhancement. Systematic studies using different Raman probes have been implemented, but one of the most commonly used Raman probes, rhodamine 6G (R6G), has yielded controversial results for the enhancement effect on graphene. Indeed, the Raman enhancement factor of R6G induced by graphene has never been measured directly under resonant excitation because of the presence of intense fluorescence backgrounds. In this study, a polarization-difference technique is used to suppress the fluorescence background by subtracting two spectra collected using different excitation laser polarizations. As a result, enhancement factors are obtained ranging between 1.7 and 5.6 for the four Raman modes of R6G at 611, 1,183, 1,361, and 1,647 cm[superscript −1] under resonant excitation by a 514.5 nm laser. By comparing these results with the results obtained under non-resonant excitation (632.8 nm) and pre-resonant excitation (593 nm), the enhancement can be attributed to static chemical enhancement (CHEM) and tuning of the molecular resonance. Density functional theory simulations reveal that the orbital energies and densities for R6G are modified by graphene dots.National Natural Science Foundation (China) (Nos. 21233001, 50972001, and 21129001)China. Ministry of Science and Technology (Nos. 2011YQ0301240201 and 2011CB932601)Beijing Natural Science Foundation (No. 2132056

Overtone spectra and intensities of tetrahedral molecules in boson-realization models

The stretching and bending vibrational spectrum and the intensities of infrared transitions in a tetrahedral molecule are studied in two boson-realization models, where the interactions between stretching and bending vibrations are described by a quadratic cross term and by Fermi resonance terms, called harmonically coupled and Fermi resonance boson-realization model, respectively. The later is a development of our recent model. As an example, the two models are applied to the overtone spectrum and the intensities of silicon tetrafluorde. Those models provide fits to the published experimental vibrational eigenvalues with standard deviations 1.956 cm$^{-1}$ and 0.908 cm$^{-1}$, respectively. The intensities of infrared transitions of its complete vibrations are calculated in the two models, and results show a good agreement with the observed data.Comment: 14 pages Revtex, no figure, to appear in Annals of Physic

Highly selective recognition of Al3+ and I- ions using a bifunctional fluorescent probe

A tripodal fluorescent probe L1 armed with rhodamine B and 1-naphthaleneisothiocyanates was prepared in high yield. A study of the recognition properties revealed that probe L1 exhibited high sensitivity and selectivity towards Al3⁺ through a “FRET” fluorescence response and colorimetric response with low detection limits of the order of 10-8 M. Meanwhile, probe L1 also possessed high recognition capability for I⁻ through fluorescent decay, which given there are comparatively few selective fluorescent probes for I⁻, is significant. Furthermore, the complexation mechanisms were fully investigated by spectral titrations, 1H NMR spectroscopic titrations and mass spectrometry. The utility of probe L1 as a biosensor in living cells (PC3 cells) towards Al3⁺ ions has also been demonstrated