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Research into ant colony algorithms for solving continuous optimization problems forms one of the most significant and promising areas in swarm computation. Although traditional ant algorithms are designed for combinatorial optimization, they have shown great potential in solving a wide range of optimization problems, including continuous optimization. Aimed at solving continuous problems effectively, this paper develops a novel ant algorithm termed "continuous orthogonal ant colony" (COAC), whose pheromone deposit mechanisms would enable ants to search for solutions collaboratively and effectively. By using the orthogonal design method, ants in the feasible domain can explore their chosen regions rapidly and efficiently. By implementing an "adaptive regional radius" method, the proposed algorithm can reduce the probability of being trapped in local optima and therefore enhance the global search capability and accuracy. An elitist strategy is also employed to reserve the most valuable points. The performance of the COAC is compared with two other ant algorithms for continuous optimization -API and CACO by testing seventeen functions in the continuous domain. The results demonstrate that the proposed COAC algorithm outperforms the others.

Research on optimization of the job shop scheduling problem (JSP) is one of the most significant and promising areas of optimization. Instead of the traditional optimization method, this paper presents an investigation into the use of an Ant Colony System (ACS) to optimize the JSP. The main characteristics of this system are positive feedback, distributed computation, robustness and the use of a constructive greedy heuristic. In this paper, an improvement of the performance of ACS will be discussed. The numerical experiments of ACS were implemented in a small JSP. The optimized results of the ACS are favourably compared with the traditional optimization methods.

Liquid−liquid equilibrium data are presented for mixtures of 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([C2OHmim]BF4) or 1-(2-hydroxyethyl)-2,3-dimethylimidazolium tetrafluoroborate ([C2OHdmim]BF4) + water + 1-butanol at 293.15 K. The data presented provide valuable insight into how the environmentally friendly ionic liquid solvent can be used to separate 1-butanol and water. Selectivity values, derived from the tie line data, show that [C2OHdmim]BF4 has better extraction capacity than [C2OHmim]BF4. The experimental results show that the two ionic liquids are potentially candidates to separate 1-butanol and water by liquid−liquid extraction. The experimental tie lines were correlated with the NTRL equation.

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[1] This study uses the Argos satellite-tracked surface drifter trajectory data and ENVISAT (European satellite) ASAR (advanced synthetic aperture radar) images to illustrate the ocean vortex trains (OVT) in the Luzon Strait. Two cases that occurred in the northwest of Babuyan Island are observed. The first train of three cyclonic vortices showed up on drifter trajectories from 20°to 20.5°N and from 120°to 121°E, and the second, consisting of five pairs of cyclonic-anticyclonic vortices, occurred on the upstream side of the first one from 19.5°to 20.0°N and from 121.0°to 122.0°E and showed up on the ASAR images acquired on 19 November 2006. The total length of the vortex train axis reaches about 250 km. All vortices propagate northwestward ($315°TN). The mean angular velocity is (2.07 ± 0.18) Â 10 À5 s À1 . Theoretical models of ocean vortex radar image derived from radar imaging theories are used to extract dynamical parameters from ASAR imagery signatures, which include the distance between two consecutive vortices and that between two rows of vortices of (22.6 ± 1.9) km and (8.2 ± 1.2) km, respectively, the maximum rotational velocity radius as 4.70 km, and the vortex rotational angular velocity 3 Â 10 À5 s À1 . Dynamical analyses give the mean velocity of the current of 0.65 ms À1 , and the propagation velocity of the vortex 0.58 ms À1 . The vortex shedding rate is estimated as 2.57 Â 10 À5 s À1 . The Reynolds number is estimated as 50 to 500. For the individual vortex and the vortex train, the Rossby numbers are O(0.4), and O(0.5), respectively, implying that both vortex and vortex train observed in the Luzon Strait have a sub-mesoscale nature. This study also reveals a strong current with an average surface current velocity of around 0.7 ms À1 and the direction of around 315°TN flowing directly from the Pacific to SCS passing through the southern Luzon Strait. The mean flow velocity can be calculated using methods developed in this study and OVT dynamical models. This information may provide more insight to the circulation systems in the area including the origin of Kuroshio.