Analysis of the efficiency of electronic reverse auction settings: big data evidence

Electronic Commerce Research - Despite the existence of research in the field of electronic reverse auctions (eRAs), there is still a limited understanding of the determinants of auction savings...     

SDN Based Mobile Networks: Concepts and Benefits

Mobile Internet traffic is expected to grow faster than the fixed Internet traffic in a near future. Since, today’s broadband networks are approaching theoretical limits in terms of spectral efficiency per link, mobile operators are compelled to seek for new solutions that will be able to accommodate the expected traffic growth and improve their position in the competitive market. Addressing those challenges with current inflexible, not scalable and complex architecture is very hard, if possible at all. Software defined networking (SDN) is a new networking architecture paradigm that holds great promise to overcome many of mentioned limitations and provides required improvements in performance by decoupling control functions from underlying physical infrastructure. In this paper, we explain key reasons for transition to SDN based mobile networks and briefly describe several proposals of design scenario. Special emphasis is placed on SDN’s contribution to more efficient inter-cell interference management, traffic control and network virtualization.     

Iron-Sepiolite High-Performance Magnetorheological Polishing Fluid with Reduced Sedimentation

A sedimentation-stable magnetorheological (MR) polishing slurry on the basis of ferrofluid, iron particles, Al₂O_3, and clay nanofiller in the form of sepiolite intended for MR polishing has been designed, prepared, and its polishing efficiency verified. Added clay substantially improved sedimentation stability of the slurry, decreasing its sedimentation rate to a quarter of its original value (1.8 to 0.45 mg s⁻¹) while otherwise maintaining its good abrasive properties. The magnetisation curve measurement proved that designed slurry is soft magnetic material with no hysteresis, and its further suitability for MR polishing was confirmed by its magnetorheology namely in the quadratically increased yield stress due to the effect of applied magnetic field (0 to 600 kA m⁻¹). The efficiency of the MR polishing process was tested on the flat samples of injection-moulded polyamide and verified by surface roughness/3D texture measurement. The resulting new composition of the MR polishing slurry exhibits a long-term stable system with a wide application window in the MR polishing process.     

Determination of the grinding wheel profile and its setup for use in finishing cylindrical gears with an evolvent profile

The present work is a continuation of the first part of the article and is devoted to the geometric calculation of shape parameters of the working surfaces of disk-shaver teeth for use in finishing cylindrical gears with an evolvent profile. A method has been proposed for determining the shape of the working surfaces in disk-shaver teeth during the recessed shaving of cylindrical gears with technologically modified teeth. In this case, the machined gear tooth surfaces are discretely specified, and consequently familiar analytical methods of tool profiling are unacceptable.     

Target approach in biological systems

In certain applications such as prosthetics or manipulation in a hostile environment it is necessary to approach a selected target with an artificial arm. In this paper specific features of target approach in biological systems are outlined having in view the design of automata with similar performances. The theoretical basis for the design of servoarms is found in optimal control theory. A control law serving the above purpose is developed, the synthesis procedure for the optimal controller is presented as well as some experimental checks on a human operator.     

Application priority mathematical model of operating parameters in advanced manufacturing technology

The present work is devoted to the geometric calculation of shape parameters of the working surfaces of disk-shaver teeth for use in finishing cylindrical gears with an evolvent profile. These are primarily gears for the transmissions of cars and light trucks, which must meet strict noise requirements. This imposes corresponding requirements on their machining precision.     

Determination of Ketchup Sensory Texture Acceptability and Examination of Determining Factors as a Basis for Product Optimization

The aim of this study was to examine possible usage of instrumental determination of selected texture parameters to estimate sensory texture acceptability of ketchups. Likewise, the authors focused on examination whether the consumer’s perception of texture acceptability is connected to the selected factors related to the ingredients and production technology. Yet another aim was to describe the selected textural parameters of ketchups available in the European market. Within the frame of this study, 29 samples of ketchups were analyzed by means of instrumental and sensory texture analysis. Further, a survey research was carried out with the results showing that the texture was the second most significant parameter for the consumer’s choice of a particular product. The average evaluation of sensory texture acceptability reached the values from 3.78 to 7.67. Analysis of the evaluation results of textural parameters based on the values of Pearson’s correlation coefficient confirmed a high correlation (p < 0.05) between instrumental and sensory determined viscosity and density. However, none of these partial textural parameters affected the sensory acceptability of the texture separately. Thus, using the instrumental analysis for estimation of the sensory texture acceptability of ketchups is not possible. For the optimization and control of ketchup texture in practice, sensory analysis is essential.