ALBERT

Description: The problem addressed here is a combinatorial bilevel programming problem called the uncapacitated facility location problem with customer’s preferences. A hybrid algorithm is developed for solving a battery of benchmark instances. The algorithm hybridizes an evolutionary algorithm with path relinking; the latter procedure is added into the crossover phase for exploring the trajectory between both parents. The proposed algorithm outperforms the evolutionary algorithm already existing in the literature. Results show that including a more sophisticated procedure for improving the population through the generations accelerates the convergence of the algorithm. In order to support the latter statement, a reduction of around the half of the computational time is obtained by using the hybrid algorithm. Moreover, due to the nature of bilevel problems, if feasible solutions are desired, then the lower level must be solved for each change in the upper level’s current solution. A study for illustrating the impact in the algorithm’s performance when solving the lower level through three different exact or heuristic approaches is made.

Description: The main aspects related to the charge transfer reactions occurring at the interface between two immiscible electrolyte solutions (ITIES) are described. The particular topics to be discussed involve simple ion transfer. Focus is given on theoretical approaches, numerical simulations, and experimental methodologies. Concerning the theoretical procedures, different computational simulations related to simple ion transfer are reviewed. The main conclusions drawn from the most accepted models are described and analyzed in regard to their relevance for explaining different aspects of ion transfer. We describe numerical simulations implementing different approaches for solving the differential equations associated with the mass transport and charge transfer. These numerical simulations are correlated with selected experimental results; their usefulness in designing new experiments is summarized. Finally, many practical applications can be envisaged regarding the determination of physicochemical properties, electroanalysis, drug lipophilicity, and phase-transfer catalysis.

Description: We present a review of the basics of supermanifold theory (in the sense of Berezin-Kostant-Leites-Manin) from a physicist's point of view. By considering a detailed example of what does it mean the expression “to integrate an ordinary superdifferential equation” we show how the appearance of anticommuting parameters playing the role of time is very natural in this context. We conclude that in dynamical theories formulated whithin the category of supermanifolds, the space that classically parametrizes time (the real line ℝ) must be replaced by the simplest linear supermanifold ℝ1|1. This supermanifold admits several different Lie supergroup structures, and we analyze from a group-theoretic point of view what is the meaning of the usual covariant superderivatives, relating them to a change in the underlying group law. This result is extended to the case of N-supersymmetry.

Description: This research highlights the use of game theory to solve the classical problem of the uncapacitated facility location optimization model with customer order preferences through a bilevel approach. The bilevel model provided herein consists of the classical facility location problem and an optimization of the customer preferences, which are the upper and lower level problems, respectively. Also, two reformulations of the bilevel model are presented, reducing it into a mixed-integer single-level problem. An evolutionary algorithm based on the equilibrium in a Stackelberg’s game is proposed to solve the bilevel model. Numerical experimentation is performed in this study and the results are compared to benchmarks from the existing literature on the subject in order to emphasize the benefits of the proposed approach in terms of solution quality and estimation time.

Description: The main goal of intelligent surveillance consists in providing security systems with the skills required for correctly detecting and analyzing events in monitored environments. Since these environments are complex and the information is distributed through them, the use of agent-based approaches has become more and more popular when monitoring moving objects. This paper describes how an existing agent platform has been adopted and used to give support to intelligent surveillance systems. Agents deployed by means of this platform implement a behavior-based model that is flexible enough to deal with the challenges that monitored environments pose. Two case studies of urban traffic environments are discussed to prove the feasibility of the proposal.

Description: In this work, we synthesized In2S3 powder through chemical bath deposition method (CBD) in acid medium; we used thioacetamide as sulphide source and InCl3 as indium ion source. X-ray diffraction, diffuse reflection, and Raman spectroscopy measurements were used for In2S3 powder physicochemical characterization. Optical analysis indicated that In2S3 was active in the visible region of electromagnetic spectrum; it had a band gap of 2.47 eV; the diffraction patterns and Raman spectroscopy suggested that powder had polycrystalline structure. Furthermore, we also studied the adsorption process of methylene blue (MB) on In2S3 powder; adsorption studies indicated that the Langmuir model describes experimental data. Finally, photocatalytic degradation of MB was studied under visible irradiation in aqueous solution; besides, pseudo-first-order model was used to obtain kinetic information about photocatalytic degradation; results indicated that the powder catalyst reduces 26% concentration of MB under visible irradiation.

Description: In this work, we fabricated system In(O,OH)S/i-ZnO/n+-ZnO to be used as potential optical window in thin films solar cells. i-ZnO/n+-ZnO thin films were synthesized by reactive evaporation (RE) method and In(O,OH)S thin films were synthesized by chemical bath deposition (CBD) method; all thin films were deposited on soda lime glass substrates. Thin films were characterized through X-ray diffraction (XRD), atomic force microscopy (AFM), and spectral transmittance measurements. Structural results indicated that both thin films were polycrystalline; furthermore, morphological results indicated that both thin films coated uniformly soda lime glass substrate; besides, optical characterization indicated that system had more than 80% of visible radiation transmittance.

Description: A great amount of new applied problems in the area of energy networks has recently arisen that can be efficiently solved only as mixed-integer bilevel programs. Among them are the natural gas cash-out problem, the deregulated electricity market equilibrium problem, biofuel problems, a problem of designing coupled energy carrier networks, and so forth, if we mention only part of such applications. Bilevel models to describe migration processes are also in the list of the most popular new themes of bilevel programming, as well as allocation, information protection, and cybersecurity problems. This survey provides a comprehensive review of some of the above-mentioned new areas including both theoretical and applied results.

Description: Background. Maternal fever during labor epidural analgesia (LEA) may cause increased maternal and cord serum inflammatory cytokines. We report the effects of intermittent and continuous LEA on these cytokines.Methods. Ninety-two women were randomly assigned to continuous (CLEA) or intermittent (ILEA) groups, 46 in each. Maternal temperature was checked and blood drawn at epidural insertion (baseline) and four-hourly until 4 h postpartum (4 PP). Cord blood was drawn after placental delivery. Interleukin-1β(IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), granulocyte macrophage-colony stimulating factor (GM-CSF), and tumor necrosis factor-α(TNF-α) were measured and analyzed according to group randomization, and then combined and reanalyzed as febrile (temperature ≥38°C) or afebrile groups.Results. Significant intragroup changes from baseline were noted in some groups. Data are pg/mL, median (Q1/Q3). IL-6 rose at all time points in all groups.CLEA: baseline: 18.5 (12.5/31.1), 4 h: 80.0 (46.3/110.8), 8 h: 171.9 (145.3/234.3), and 4 PP: 81 (55.7/137.4).ILEA: baseline: 15.7 (10.2/27.1), 4 h: 68.2 (33.3/95.0), 8 h: 125.0 (86.3/195.0), and 4 PP: 70.2 (54.8/103.6).Febrile group: baseline: 21.6 (13.8/40.9), 4 h: 83.9 (47.5/120.8), 8 h: 186.7 (149.6/349.9), and 4 PP: 105.8 (65.7/158.8).Afebrile group: baseline: 10.9 (2.1/17.4), 4 h: 38.2 (15.0/68.2), 8 h: 93.8 (57.1/135.7), and 4 PP: 52.9 (25.1/78). IL-8 rose at all time points inCLEA: baseline: 2.68 (0.0/4.3), 4 h: 3.7 (0.0/6.5), 8 h: 6.0 (3.3/9.6), 4 PP: 5.6 (0.8/8.0), andafebrile groupbaseline: 2.5 (0.0/4.7), 4 h: 3.3 (0.0/6.2), 8 h: 5.3 (1.9/9.8), and 4 PP: 4.7 (0.0/7.6). It fell at 4 PP infebrile group: baseline: 4.1 (0.0/6.4), 4 h: 3.8 (0.0/6.5), 8 h: 5.2 (2.5/8.0), and 4 PP: 2.9 (0.0/4.0). GM-CSF increased at 8 h and decreased at 4 PP inILEAbaseline: 2.73 (0.0/7.2), 4 h: 2.73 (0.0/7.9), 8 h: 3.9 (2.7/11.5), and 4 PP: 2.0 (0.0/7.2). It increased at 4 h and 8 h and decreased at 4 PP infebrilegroup: baseline: 2.6 (0.0/4.2), 4 h: 3.2 (2.1/7.0), 8 h: 4.0 (3.2/12.3), and 4 PP: 2.4 (1.7/12.6). There were no intergroup cytokine changes in maternal or cord serum in CLEA versus ILEA or febrile versus afebrile groups.Conclusions. Some cytokines, especially IL-6, rise physiologically during labor epidural analgesia.