Differential evolution with an individual-dependent mechanism

Differential evolution (DE) is a well-known optimization algorithm that utilizes the difference of positions between individuals to perturb base vectors and thus generate new mutant individuals. However, the difference between the fitness values of individuals, which may be helpful to improve the performance of the algorithm, has not been used to tune parameters and choose mutation strategies. In this paper, we propose a novel variant of DE with an individual-dependent mechanism that includes an individual-dependent parameter (IDP) setting and an individual-dependent mutation (IDM) strategy. In the IDP setting, control parameters are set for individuals according to the differences in their fitness values. In the IDM strategy, four mutation operators with different searching characteristics are assigned to the superior and inferior individuals, respectively, at different stages of the evolution process. The performance of the proposed algorithm is then extensively evaluated on a suite of the 28 latest benchmark functions developed for the 2013 Congress on Evolutionary Computation special session. Experimental results demonstrate the algorithm's outstanding performance

Research into container reshuffling and stacking problems in container terminal yards

Container stacking and reshuffling are important issues in the management of operations in a container terminal. Minimizing the number of reshuffles can increase productivity of the yard cranes and the efficiency of the terminal. In this research, the authors improve the existing static reshuffling model, develop five effective heuristics, and analyze the performance of these algorithms. A discrete-event simulation model is developed to animate the stacking, retrieving, and reshuffling operations and to test the performance of the proposed heuristics and their extended versions in a dynamic environment with arrivals and retrievals of containers. The experimental results for the static problem show that the improved model can solve the reshuffling problem more quickly than the existing model and the proposed extended heuristics are superior to the existing ones. The experimental results for the dynamic problem show that the results of the extended versions of the five proposed heuristics are superior or similar to the best results of the existing heuristics and consume very little time

Model and heuristic solutions for the multiple double-load crane scheduling problem in slab yards

This article studies a multiple double-load crane scheduling problem in steel slab yards. Consideration of multiple cranes and their double-load capability makes the scheduling problem more complex. This problem has not been studied previously. We first formulate the problem as a mixed-integer linear programming (MILP) model. A two-phase model-based heuristic is then proposed. To solve large problems, a pointer-based discrete differential evolution (PDDE) algorithm was developed with a dynamic programming (DP) algorithm embedded to solve the one-crane subproblem for a fixed sequence of tasks. Instances of real problems are collected from a steel company to test the performance of the solution methods. The experiment results show that the model can solve small problems optimally, and the solution greatly improves the schedule currently used in practice. The two-phase heuristic generates near-optimal solutions, but it can still only solve comparatively modest problems within reasonable (4 h) computational timeframes. The PDDE algorithm can solve large practical problems relatively quickly and provides better results than the two-phase heuristic solution, demonstrating its effectiveness and efficiency and therefore its suitability for practical use

Scheduling the operations of a double-load crane in slab yards

This paper studies a double-load crane scheduling problem (DLCSP) in steel slab yards. A slab yard stores slabs in stacks. To prepare for use in production, some slabs need to be moved from one place to another. These movement tasks are performed by a double-load crane which can hold up to two slabs simultaneously. Given a set of tasks and possibly precedence relationship among them, the scheduling problem is to allocate the tasks to double-load operations and determine the schedule for the crane to perform the tasks so as to minimize the makespan. The problem is first formulated as a mixed integer linear programming (MILP) model with variables representing the order of tasks. Based on properties of the problem, it is then reformulated from a crane operation perspective. Computational experiments are carried out on practical data collected from a steel company. The results show that both models can solve practical sized problems optimally, with the second model being more efficient

Catalytic Asymmetric Formal Aza-Diels–Alder Reactions of α,β-Unsaturated Ketones and 3<i>H</i>‑Indoles

Asymmetric formal aza-Diels–Alder reactions with α,β-unsaturated ketones and 3<i>H</i>-indoles with disubstituted groups on the C3 position catalyzed by primary amine-thiourea bifunctional catalyst have been developed. The reactions produced chiral hexahydropyrido-[1,2-<i>a</i>]-indole-2-ones in high yields with excellent diastereo- and enantioselectivities

How Surface and Substrate Chemistry Affect Slide Electrification

When water droplets move over a hydrophobic surface, they and the surface become oppositely charged by what is known as slide electrification. This effect can be used to generate electricity, but the physical and especially the chemical processes that cause droplet charging are still poorly understood. The most likely process is that at the base of the droplet, an electric double layer forms, and the interfacial charge remains on the surface behind the three-phase contact line. Here, we investigate the influence of the chemistry of surface (coating) and bulk (substrate) on the slide electrification. We measured the charge of a series of droplets sliding over hydrophobically coated (1–5 nm thickness) glass substrates. Within a series, the charge of the droplet decreases with the increasing droplet number and reaches a constant value after about 50 droplets (saturated state). We show that the charge of the first droplet depends on both coating and substrate chemistry. For a fully fluorinated or fully hydrogenated monolayer on glass, the influence of the substrate on the charge of the first droplet is negligible. In the saturated state, the chemistry of the substrate dominates. Charge separation can be considered as an acid base reaction between the ions of water and the surface. By exploiting the acidity (Pearson hardness) of elements such as aluminum, magnesium, or sodium, a positive saturated charge can be obtained by the counter charge remaining on the surface. With this knowledge, the droplet charge can be manipulated by the chemistry of the substrate

CART Peptide Decreases the Caffeine-induced Increase in the pCaMKIIα–D₃R Interaction Level.

<p>(<b>a</b>) Experimental timeline and location of the injection cannula tips for the rats included in the data analyses. (<b>b</b>) A representative western blot labeled with antibodies against pan-PMCA. (<b>c</b>) A representative western blot labeled with antibodies against pCaMKIIα. The membranes were scanned, and the band intensities were quantified by measuring the relative density (relative OD) of the immunoreactive signals of PMCA and pCaMKIIα to GAPDH. (<b>d</b>) Immunoblot analysis of D₃R expression was performed on pCaMKIIα immunoprecipitates. <b>e</b> Immunoblot analysis of pCaMKIIα expression was performed on D₃R immunoprecipitates. The membranes were scanned, and the band intensities were quantified by measuring the arbitrary OD of the pCaMKIIα or D₃R bands. The data are presented as the means ± SEM of each group (n = 4/group). ***<i>p</i><0.001, compared to the saline group; ^##<i>p</i><0.01 and ^###<i>p</i><0.001, compared to the caffeine group. Symbols indicate significant differences as revealed by two-way ANOVA followed by Bonferroni’s <i>post hoc</i> test. Symbols represent different groups: □, saline (intra-NAc)-saline (p.o.); ■, saline-caffeine; ▩, CART 55–102 (0.08 μM/side)-saline; ▨, CART 55-102-caffeine.</p

Decreased Caffeine-Induced Locomotor Activity via Microinjection of CART Peptide into the Nucleus Accumbens Is Linked to Inhibition of the pCaMKIIa-D₃R Interaction

<div><p>The purpose of this study was to characterize the inhibitory modulation of cocaine- and amphetamine-regulated transcript (CART) peptides, particularly with respect to the function of the D₃ dopamine receptor (D₃R), which is activated by its interaction with phosphorylated CaMKIIα (pCaMKIIα) in the nucleus accumbens (NAc). After repeated oral administration of caffeine (30 mg/kg) for five days, microinjection of CART peptide (0.08 μM/0.5 μl/hemisphere) into the NAc affected locomotor behavior. The pCaMKIIα-D₃R interaction, D₃R phosphorylation and cAMP/PKA/phosphorylated CREB (pCREB) signaling pathway activity were measured in NAc tissues, and Ca²⁺ influx and pCaMKIIα levels were measured in cultured NAc neurons. We found that CART attenuated the caffeine-mediated enhancement of depolarization-induced Ca²⁺ influx and CaMKIIα phosphorylation in cultured NAc neurons. Repeated microinjection of CART peptides into the NAc decreased the caffeine-induced enhancement of Ca²⁺ channels activity, pCaMKIIα levels, the pCaMKIIα-D₃R interaction, D₃R phosphorylation, cAMP levels, PKA activity and pCREB levels in the NAc. Furthermore, behavioral sensitization was observed in rats that received five-day administration of caffeine following microinjection of saline but not in rats that were treated with caffeine following microinjection of CART peptide. These results suggest that caffeine-induced CREB phosphorylation in the NAc was ameliorated by CART peptide due to its inhibition of D₃R phosphorylation. These effects of CART peptides may play a compensatory role by inhibiting locomotor behavior in rats.</p></div

CART Peptide Decreases Caffeine-induced CaMKIIα Phosphorylation in Cultured Accumbal Neurons.

<p>(<b>a</b>) Experimental timeline. (<b>b</b>) A representative western blot labeled with antibodies against pCaMKIIα. The membranes were scanned, and the band intensities were quantified by measuring the relative density (relative OD) of the immunoreactive signals of pCaMKIIα to GAPDH. (<b>c</b>) Representative immunofluorescence images of accumbal neurons stained with antibodies against pCaMKIIα. (<b>d</b>) Bar graph showing quantification of pCaMKIIα expression in cultured NAc cells (c). The data are presented as the group means ± SEM (n = 4/group). *<i>p</i><0.05 and **<i>p</i><0.01 compared to the saline group; ^#<i>p</i><0.05 and ^##<i>p</i><0.01 compared to the caffeine group. Symbols indicate significant differences as revealed by two-way ANOVA followed by Bonferroni’s <i>post hoc</i> test. Symbols represent different groups: □, saline (intra-NAc)-saline (p.o.); ■, saline-caffeine; ▩, CART 55–102 (0.08 μM/side)-saline; ▨, CART 55-102-caffeine.</p

CART Peptide Decreases Caffeine-enhanced Depolarization-induced Ca²⁺ Influx in Cultured NAc Neurons.

<p>(<b>a</b>) Experimental timeline. (<b>b</b>) K⁺ depolarization-induced Ca²⁺ influxes in NAc neurons were recorded in the presence of 0 or 10 mM caffeine. (<b>c</b>) Depolarization-induced Ca²⁺ influx was recorded under control conditions after a single 5-min application of 1 μM CART 55–102 peptide and after a single 5-min application of 10 mM caffeine. High K⁺ (35 mM) application is indicated by the <i>short bars</i>, and CART 55–102 peptide application is indicated by the <i>long bars</i>. (<b>d</b>) Bar graph showing the quantification of Ca²⁺ influx in cultured NAc cells (c). The data are shown as the group means ± SEM (n = 5/group). **<i>p</i><0.01 compared to the control group (one-way ANOVA followed Dunnett’s <i>post hoc</i> test). ^###<i>p</i><0.001, compared to the caffeine group (one-way ANOVA followed Bonferroni’s <i>post hoc</i> test).</p