Demand sensing in e-business

In this paper, we identify various models from the optimization and econometrics literature that can potentially help sense customer demand in the e-business era. While modelling reality is a difficult task, many of these models come close to modelling the customer's decision-making process. We provide a brief overview of these techniques, interspersing the discussion occasionally with a tutorial introduction of the underlying concepts.     

Synthesis of nanocomposite gold-semiconductor materials by seed-growth method

Gold-semiconductor nanocomposite hybrid materials were synthesized by applying the seed-growth approach. Citrate stabilized gold nanoparticles were prepared by the reduction of HAuCl₄ with borohydride and used as seeds. The structural and morphological features of semiconductor materials i.e. CdS, CuS, NiS, and PbS in the presence of Au NP were examined with the help of UV-Visible spectroscopy, phase contrast microscopy, transmission electron microscopy (TEM) and X-ray diffraction measurements. The experimental results revealed that a network of semiconductor-Au NP nanocomposite material is formed in each case.     

Extended Release of Theophylline Through Sodium Alginate Hydrogel Beads: Effect of Glycerol on Entrapment Efficiency,Drug Release

Theophylline is the most useful bronchodilators for the treatment of severe reversible bronchospasm. The fluctuations of serum theophylline level in clinical practice and associated central nervous system side effects necessitate the development of an extended release formulation. In the present study, theophylline-loaded beads were prepared by extruding the dispersion of theophylline, sodium alginate, and glycerol into the cationic crosslinking solution of calcium chloride. The effect of the addition of glycerol was determined by entrapment efficiency, drug release, and morphology of beads. Absence of chemical interaction between drug, polymer, and counterions after production of beads was confirmed by Fourier transform infrared spectroscopy. Theophylline entrapment of up to 72% was achieved in beads with almost spherical shape and size ranging from 0.67 to 1.12 mm. Percentage entrapment of theophylline found to be more and release was extended up to the eleventh hour from the glycerol containing sodium alginate beads. Hence, sodium alginate glycerol beads could represent a promising oral drug delivery system to extend the release of theophylline.     

Low Thermal Conductivity and High Thermoelectric Performance in In<Subscript>4</Subscript>Se<Subscript>3−<Emphasis Type="Italic">x</Emphasis></Subscript> with Phase-Separated Indium Inclusions

We report the thermoelectric properties of undoped hot-pressed In₄Se_3?x (x = 0.05). Stoichiometric imbalance due to selenium deficiency in In₄Se₃ was found to create a secondary phase of elemental indium in the host material. Heat treatment drove grain growth and increased the indium solubility in In₄Se₃. Indium-rich domains at grain surfaces/boundaries in untreated samples were found to redistribute inside the grains and their junctions after heat treatment. Due to enhanced phonon scattering by secondary phase of indium, very low values of thermal conductivity were observed for all samples, leading to a maximum thermoelectric figure of merit (zT) of 1.13 at 723 K along the hot-pressing direction for the heat-treated sample.     

On the decision fusion for cooperative spectrum sensing in cognitive radio networks

Cooperation among different cognitive radios is used to enhance the sensing performance by exploiting the multiuser diversity. Soft and Hard decision fusion schemes are usually employed at the fusion center to detect the presence or absence of primary user. Soft decision fusion schemes perform better than hard fusion schemes but at the cost of increased bandwidth burden on the control channel. In this context, we propose a semi-soft fusion scheme to achieve a tradeoff between sensing performance and bandwidth cost. Under this scheme, each cognitive radio makes a local decision and sends one or two-bit data to the fusion center based on the observed test statistics. On the basis of received data, fusion center estimates the global test statistics which are then compared to a predetermined threshold to make the final decision. Furthermore, a closed form expression for average bandwidth cost for the proposed scheme is also derived. MATLAB simulation demonstrates that the performance of the proposed semi-soft fusion approaches to that of soft fusion scheme with a remarkable reduction in the bandwidth cost of control channel.     

A weighted possibilistic programming approach for sustainable vendor selection and order allocation in fuzzy environment

This paper focused on the analysis of imprecise information in terms of many critical parameters for a multi-objective multi-item vendor selection-order allocation problem with price-breaks. We used both quantitative and qualitative criteria taking into account the economic, technological, social, environmental factors, and the price-breaks that were offered on order quantity following ‘all-unit discount schedule.’ We developed an optimization model that integrated fuzzy multi-objective integer linear programming and analytic hierarchy process techniques. A weighted possibilistic programming approach was presented to solve the optimization model, which simultaneously minimized (maximized) the best scenario, the likeliest scenario, and the worst scenario for the imprecise objective functions thereby avoiding situations that may force the solution process to divert. The integrated model and the solution approach were tested on the data set of an industrial case study. A detailed performance analysis and comparisons were done to show superiority of the proposed methodology over the existing related fuzzy programming approaches.     

Effects of polymer doping on dielectric and electro‐optical parameters of nematic liquid crystal

Poly(isobutyl methacrylate) (PiBMA) polymer doped in pure p‐Ethoxybenzylidene p‐Heptylaniline (EBHA) mesomaterial has been investigated in the present study. The dielectric and electro‐optical parameters of EBHA having nematic phase were altered due to the addition of polymer in different concentration. The strong dopant concentration dependent nature of negative dielectric anisotropy and conductivity are the interesting results of the present polymer doped nematic liquid crystal (NLC) system. The present composite shows its useful application in low charge consumable devices due to the easy charge transportation phenomenon. The investigated polymer doped‐NLC system exhibiting increased negative dielectric anisotropy and high conductivity may prove to be advantageous for video applications in vertically aligned cells. POLYM. ENG. SCI., 55:414–420, 2015. © 2014 Society of Plastics Engineers     

Brønsted Acid‐Catalyzed Enantioselective Synthesis of Isatin‐ Derived N,S‐Acetals

The enantioselective organocatalytic nucleophilic addition of thiols to isatin‐derived ketimines has been developed utilizing only 1 mol% of an enantiopure BINOL‐derived phosphoric acid. The new protocol provides a series of isatin‐derived N,S‐acetals in high yields (up to 98%) and high enantioselectivities (up to 93% ee).