Pythagorean Dombi fuzzy aggregation operators with application in multicriteria decision-making

A Pythagorean fuzzy set, an extension of intuitionistic fuzzy sets, is very helpful in representing vague information that occurs in real world scenarios. The Dombi operators with operational parameters, have excellent flexibility. Due to the flexible nature of these Dombi operational parameters, this research paper introduces some new aggregation operators under Pythagorean fuzzy environment, including Pythagorean Dombi fuzzy weighted arithmetic averaging (PDFWAA) operator, Pythagorean Dombi fuzzy weighted geometric averaging (PDFWGA) operator, Pythagorean Dombi fuzzy ordered weighted arithmetic averaging operator and Pythagorean Dombi fuzzy ordered weighted geometric averaging operator. Further, this paper presents several advantageous characteristics, including idempotency, monotonicity, boundedness, reducibility and commutativity of preceding operators. By utilizing PDFWAA and PDFWGA operators, this article describes a multicriteria decision-making (MCDM) technique for solving MCDM problems. Finally, a numerical example related to selection of a leading textile industry is presented to illustrate the applicability of our proposed technique.     

Dynamic optimisation for highly agile supply chains in e-procurement context

In the conditions of an increased worldwide competition, supply chains are struggling to respond to an increasingly volatile and complex environment. With technological advances, current practices to build efficient supply chains have changed. Companies are seeking to use internet in order to cope with the flexible and dynamic nature of logistics networks. The purpose of this article is to address the flexible dynamic e-procurement context under asynchronous and repetitive variations over time. The supply chain considered is composed of two levels (buyer–suppliers) operating in highly agile environment. The questions facing the buyer is how many units of product should be purchased and from which supplier in response to variation in term of price and capacity. Because of this highly changing environment characterised by frequent changes in a short time, most of the classical optimisation approaches seem inadequate to address these problems. Recently, dynamic optimisation has been proposed to deal with such problems. However, we have no knowledge of its application in a supply chain context. We suggest a dynamic genetic approach which is applied to an e-procurement context in aim to optimise the procurement process during time.     

Pareto Optimal Multigene Genetic Programming for Prediction of Longitudinal Dispersion Coefficient

Water Resources Management - The longitudinal dispersion coefficient (Kx) is fundamental to modeling of pollutant and sediment transport in natural rivers, but a general expression for Kx, with...     

Emulating Software Defined Network using Mininet-ns3-WIFI Integration for Wireless Networks

SDN enables a new networking paradigm probable to improve system efficiency where complex networks are easily managed and controlled. SDN allows network virtualization and advance programmability for customizing the behaviour of networking devices with user defined features even at run time. SDN separates network control and data planes. Intelligently controlled network management and operation, such that routing is eliminated from forwarding elements (switches) while shifting the routing logic in a centralized module named SDN Controller. Mininet is Linux based network emulator which is cost effective for implementing SDN having in built support of OpenFlow switches. This paper presents practical implementation of Mininet with ns-3 using Wi-Fi. Previous results reported in literature were limited upto 512 nodes in Mininet. Tests are conducted in Mininet by varying number of nodes in two distinct scenarios based on scalability and resource capabilities of the host system. We presented a low cost and reliable method allowing scalability with authenticity of results in real time environment. Simulation results show a marked improvement in time required for creating a topology designed for 3 nodes with powerful resources i.e. only 0.077 sec and 4.512 sec with limited resources, however with 2047 nodes required time is 1623.547 sec for powerful resources and 4615.115 sec with less capable resources respectively.

     

Electromechanical properties of ternary BiFeO<Subscript>3</Subscript>−0.35BaTiO<Subscript>3</Subscript>–BiGaO<Subscript>3</Subscript> piezoelectric ceramics

In the present work, composition dependent crystal structure, ferroelectric, piezoelectric, and temperature dependent dielectric properties of the BiGaO₃-modified (1–x)(0.65Bi_1.05FeO₃–0.35BaTiO₃) (BFBT35–xBG, where x?=?0.00–0.03) lead-free ceramics were systematically investigated by solid-state reaction method, followed by water quenching process. The substitution of BG successfully diffuses into the lattice of the BFBT ceramics, without changing the pseudo-cubic structure of the samples. The scanning electron microscopy (SEM) results revealed that the average grain size was increased with BG-content in BFBT system. The BFBT–xBG ceramics showed a maximum in permittivity (?_max) at temperatures (T_max) above 500 °C in the compositional range of 0.00?≤?x?≤?0.03. The electro-strain is measured to be 0.125% (d^*₃₃ ~ 250 pm/V) under unipolar fields (5 kV/mm) for BFBT–0.01BG ceramics. The same composition (x?=?0.01), large static piezoelectric constant (d₃₃ ~ 165 pC/N) and electromechanical coupling factor (k_p ~ 25%) were obtained. The above investigated characterizations suggests that BFBT–BG material is favorable for piezoelectric and high temperature applications.     

Evolution of ferroelectric and piezoelectric response by heat treatment in pseudocubic BiFeO<Subscript>3</Subscript>–BaTiO<Subscript>3</Subscript> ceramics

Heat treatment of ceramics is an important process to tailor the fine electromechanical properties. To explore the criteria for optimized heat treatment in a perovskite structure of (1–x)Bi_1.05FeO₃–xBaTiO₃ (BF–BT100x) system, the structural phase relation, ferroelectric and piezoelectric response of BF–BT36 and BF–BT40 ceramics prepared by furnace cooling (FC) and quenching process were investigated. The X-ray diffraction examination showed single pseudocubic perovskite structure for all the ceramics. The homogenous microstructure was obtained for all ceramics with relatively large grain size in the furnace cooled samples. Well saturated ferroelectric hysteresis loops and enhanced piezoelectric constant (d₃₃?=?97 pC/N) were achieved by quenching process. Dielectric curve of BF–BT36 showed large dielectric constant at its Curie temperature, however, BF–BT40 showed diffused relaxor-like dielectric anomalies. Quenched BF–BT36 samples showed typical butterfly like field induced strain curves, however negative strain decreased in BF–BT40 ceramics. From these investigated study, it is observed that BF–BT ceramics are very sensitive to the heat treatment process (furnace cooling and quenching) on the dielectric, electromechanical properties.     

Design and analysis of all-optical up- and down-wavelength converter based on FWM of SOA-MZI for 60 Gbps RZ data signal

In this paper, the design and analysis of the all-optical up- and down-wavelength converter based on four-wave mixing (FWM) effect of semiconductor optical amplifier Mach–Zehnder interferometer (SOA-MZI) have been presented. The return-to-zero (RZ) modulated data signal at a bit rate of 60 Gbps has been evaluated for error-free operation to show the feasibility of proposed system at different pump wavelength. The converted signal power and quality factor are investigated as the function of variable signal power and pump power. The optimized operating input signal power of ?5 dBm with Q-factor of \(\sim \)28 dB for RZ modulated signal by using SOA-MZI structure with enhanced FWM effect. The important contribution of these investigations that it is possible to expand the optical network with limited available channel bandwidth by utilizing the wavelength converter and gives an approach to implement wavelength converter for future hybrid optical access networks.     

Determination of gamma-emitting radionuclides in the inter-tidal sediments off Balochistan (Pakistan) Coast, Arabian Sea

Natural radionuclide contents of 226Ra, 228Ra and (40)K were studied for inter-tidal sediments collected from selected locations off the745 km long Balochistan Coast using HPGe detector based gamma-spectrometry system. The sampling zone extends from the beaches of Sonmiani (near Karachi metropolis) through Jiwani (close to the border of Iran). The natural radioactivity levels detected in various sediment samples range from 14.4 +/- 2.5 to 36.6 +/- 3.8 Bq kg(-1) for 226Ra, 9.8 +/- 1.2 to 35.2 +/- 2.0 Bq kg(-1) for (228)Ra and 144.6 +/- 9.4 to 610.5 +/- 23.9 Bq kg(-1) for (40)K. No artificial radionuclide was detected in any of the marine coastal sediment samples. 137Cs, (60)Co, 106Ru and 144Ce contents in sediment samples were below the limit of detection. The measured radioactivity levels are compared with those reported in the literature for coastal sediments in other parts of the world. The information presented in this paper will serve as the first ever local radioactivity database for the Balochistan/Makran Coastal belt of Pakistan. The presented data will also contribute to the IAEA's, Asia-Pacific Marine Radioactivity Database (ASPAMARD) and the Global Marine Radioactivity Database (GLOMARD).