A novel method for coevolving PS-optimizing negotiation strategies using improved diversity controlling EDAs

In agent-mediated negotiation systems, the majority of the research focused on finding negotiation strategies for optimizing price only. However, in negotiation systems with time constraints (e.g., resource negotiations for Grid and Cloud computing), it is crucial to optimize either or both price and negotiation speed based on preferences of participants for improving efficiency and increasing utilization. To this end, this work presents the design and implementation of negotiation agents that can optimize both price and negotiation speed (for the given preference settings of these parameters) under a negotiation setting of complete information. Then, to support negotiations with incomplete information, this work deals with the problem of finding effective negotiation strategies of agents by using coevolutionary learning, which results in optimal negotiation outcomes. In the coevolutionary learning method used here, two types of estimation of distribution algorithms (EDAs) such as conventional EDAs (S-EDAs) and novel improved dynamic diversity controlling EDAs (ID²C-EDAs) were adopted for comparative studies. A series of experiments were conducted to evaluate the performance for coevolving effective negotiation strategies using the EDAs. In the experiments, each agent adopts three representative preference criteria: (1) placing more emphasis on optimizing more price, (2) placing equal emphasis on optimizing exact price and speed and (3) placing more emphasis on optimizing more speed. Experimental results demonstrate the effectiveness of the coevolutionary learning adopting ID²C-EDAs because it generally coevolved effective converged negotiation strategies (close to the optimum) while the coevolutionary learning adopting S-EDAs often failed to coevolve such strategies within a reasonable number of generations.     

Novel Digital Cancelation Method in Presence of Harmonic Self‐Interference

In‐band full‐duplex (IFD) communication has recently attracted a great deal of interest because it potentially provides a two‐fold spectral efficiency increase over half‐duplex communications. In this paper, we propose a novel digital self‐interference cancelation (DSIC) algorithm for an IFD communication system in which two nodes exchange orthogonal frequency‐division multiplexing (OFDM) symbols. The proposed DSIC algorithm is based on the least‐squares estimation of a self‐interference (SI) channel with block processing of multiple OFDM symbols, in order to eliminate the fundamental and harmonic components of SI induced through the practical radio frequency devices of an IFD transceiver. In addition, the proposed DSIC algorithm adopts discrete Fourier transform processing of the estimated SI channel to further enhance its cancelation performance. We provide a minimum number of training symbols to estimate the SI channel effectively. The evaluation results show that our proposed DSIC algorithm outperforms a conventional algorithm.     

Fabrication of Cd-free CuInSe<Subscript>2</Subscript> solar cells using wet processes

CuInSe₂ has become an attractive material for use in the production of thin-film solar cells. Recently, energy conversion efficiencies over 20% have been achieved by CuInSe₂ solar cells created using vacuum processes. To reduce manufacturing costs, more recent efforts have focused on non-vacuum processes. In this study, we fabricated solar cells exclusively by wet processes. CuInSe₂ absorption layers and In₂S₃ buffer layers were electrochemically or chemically deposited, and ZnO window layers were formed using solution-based chemical methods. The deposited CuInSe₂ absorption layers were heat-treated to improve crystallinity. We deposited a Cd-free buffer layer of In₂S₃ using a chemical bath method on the CuInSe₂ absorption layers, and then ZnO window layers were deposited by a solution-based process. With this system, we successfully fabricated CuInSe₂ solar cells and obtained a cell efficiency of 2.38%.     

Controlled drug release of silicone‐based adhesive‐containing cross‐linked siloxane powders as a reservoir

We prepared pressure‐sensitive adhesive (PSA)‐containing cross‐linked siloxane powders (CS) as a reservoir for a transdermal drug delivery system (TDDS) and evaluated their sustained drug‐release properties. PSA, as a patch‐type adhesive, was synthesized by a hydrosilylation reaction of vinyl‐terminated polysiloxanes with hydrogen‐terminated polydimethylsiloxanes. CS was also prepared via a hydrosilylation process with vinyl‐terminated polydimethylsiloxane, 1,3,5,7‐tetramethyl‐1,3,5,7‐tetravinyltetracyclosiloxane ( ), hydrogen‐terminated polydimethylsiloxane, and dimethylhydrogenmethyl oligomeric siloxane copolymer. The results of release performances using ascorbic acid as a model drug showed a cumulative linear slope over a week, indicating a constant release performance. Our data suggest that this siloxane TDDS could be useful for constant drug release over a long period. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42154.     

Selenium Flux Effect on Cu(In,Ga)Se2 Thin Films Grown by a 3-stage Co-evaporation Process

An investigation into the effects of Se flux on absorber thin film growth at each step of a 3-stage co-evaporation process was conducted to further optimize the performance of CIGS solar cells. In ‘step I’ forming an In-Ga-Se precursor thin film during the 3-stage process, Se flux affected the preferred orientation of the CIGS crystal structure, but not the film morphology. In ‘step II’, no correlation was found between Se flux and the crystal structure, although excessively high Se flux employed throughout the 3-stage process degraded the solar cell performance. A CIGS thin film, with a (220/204) crystal orientation, minor physical surface defects and ∼20 nm thick MoSe₂ at CIGS/Mo interface, was obtained by fine control of Se flux conditions (high Se flux at ‘step I’ and low Se flux at ‘step II’) at optimum substrate temperatures. The solar cell fabricated using the aforementioned CIGS thin film showed the highest conversion efficiency of 20.02 %.     

Capacity Enhancement of Uni-directional In-band Full-Duplex Cellular Networks through Co-channel Interference Cancellation

As implementation of the in-band full duplex (IFD) transceiver becomes feasible, research interest is growing with respect to using IFD communication with cellular networks. However, the cellular network in which the IFD communication is applied inevitably suffers from an increase of the co-channel interference (CCI) due to IFD simultaneous transmission and reception. In this paper, we analyze the performance of a cellular network based on uni-directional IFD (UD-IFD) communication, wherein an IFD base station simultaneously supports downlink and uplink transmissions of half-duplex (HD) users. In addition, a multi-pair CCI cancellation (MP-CCIC) method combining CCIC and user pairing is proposed to improve the performance of the UD-IFD network. Simulation results showed that, compared to a conventional HD cellular network without using CCIC, capacity gain was not obtained in the UD-IFD cellular network. On the other hand, when applying the proposed MP-CCIC, the capacity of the UD-IFD cellular network greatly improved compared to that of an HD cellular network.     

Transdermal delivery of ondansetron hydrochloride: effects of vehicles and penetration enhancers

The effects of vehicles and penetration enhancers on the in vitro permeation of ondansetron hydrochloride (OS) across dorsal hairless mouse skins were investigated. Various types of vehicles, including ester, alcohol, and ether and their mixtures were used, and then a series of fatty acids and fatty alcohols were employed as enhancers. Among pure vehicles used, water and ethanol showed high permeation fluxes, which were 48.2 ± 23.7 and 41.9 ± 17.9 µg/cm² per h, respectively. Even though propylene glycol monocaprylate (PGMC) alone did not show a high permeation rate, the skin permeability of OS was increased by the addition of diethylene glycol monoethyl ether (DGME); the highest flux was achieved at 40% of DGME. Also, the combination of PGMC and ethanol (80:20) or PGMC and propylene glycol (PG) (60:40) increased the permeation flux by six- and two-fold, respectively, compared to PGMC alone. The synergistic enhancement was also obtained by using PG-oleyl alcohol (OAl) cosolvent. The greatest flux was attained by the addition of unsaturated fatty acids at 3% concentration to PG. The enhancement factors with the addition of oleic acid or linoleic acid to PG were about 1250 and 450, respectively. But saturated fatty acids failed to show a significant enhancing effect. When the PGMC-DGME (60:40) cosolvent system was used as a vehicle, all fatty acids, including unsaturated fatty acids, failed to show significant enhancing effects. The results indicate that the combinations of oleic acid, linoleic acid, or oleyl alcohol with PG, or PGMC-DGME (60:40) cosolvent could be used for the design of the OS transdermal system.     

Transdermal delivery of ketorolac tromethamine: effects of vehicles and penetration enhancers

The effects of vehicles and penetration enhancers on the in vitro permeation of ketorolac tromethamine (KT) across excised hairless mouse skins were investigated. Among pure vehicles examined, propylene glycol monolaurate (PGML) showed the highest permeation flux, which was 94.3 ± 17.3 µg/cm²/h. Even though propylene glycol monocaprylate (PGMC) alone did not show high permeation rate, the skin permeability of KT was markedly increased by the addition of diethylene glycol monoethyl ether (DGME); the enhancement factors were 19.0 and 17.1 at 20% and 40% of DGME, respectively. When DGME was added to PGML, the permeation fluxes were almost two times at 20-60% of DGME compared to PGML alone. In the cosolvent system consisting of propylene glycol (PG)-oleyl alcohol, the permeation rate increased as the ratio of PG increased. In the study to investigate the effect of drug concentration on the permeation rate of KT, the permeation rates increased as the drug concentration increased in all vehicles used, and the dramatic increase in permeation rate was obtained when the drug concentration was higher than its solubility. For the effects of fatty acids on the permeation of KT, five fatty acids were added to PG at concentrations of 1%-, 3%-, 5%- and 10%-caprylic acid, capric acid, lauric acid, oleic acid, and linoleic acid. The enhancing effects of fatty acids were different, depending on the concentration as well as the sort of fatty acids. The highest enhancing effect was attained with 10% caprylic acid in PG; the permeation flux was 113.6 ± 17.5 µg/cm²/h. The lag time of KT was reduced as the concentration of fatty acids increased except for caprylic acid.