A single-phase algorithm for mining high utility itemsets using compressed tree structures

Mining high utility itemsets (HUIs) from transaction databases considers such factors as the unit profit and quantity of purchased items. Two-phase tree-based algorithms transform a database into compressed tree structures and generate candidate patterns through a recursive pattern-growth procedure. This procedure requires a lot of memory and time to construct conditional pattern trees. To address this issue, this study employs two compressed tree structures, namely, Utility Count Tree and String Utility Tree, to enumerate valid patterns and thus promote fast utility computation. Furthermore, the study presents an algorithm called single-phase utility computation (SPUC) that leverages these two tree structures to mine HUIs in a single phase by incorporating novel pruning strategies. Experiments conducted on both real and synthetic datasets demonstrate the superior performance of SPUC compared with IHUP, UP-Growth, and UP-Growth+ algorithms.     

New modified-majority voter-based efficient QCA digital logic design

ABSTRACT

Quantum-dot cellular automata (QCA) is an emerging nanotechnology and a possible alternative solution to the limitation of complementary metal oxide semiconductor (CMOS) technology. One of the most attractive fields in QCA is the implementation of configurable digital systems. This article presents a novel multifunctional gate called the modified-majority voter (MMV). The proposed gate works on the explicit interaction of the cell characteristic property for the implementation of digital circuits. This prominent feature of the proposed gate reduces the maximum hardware cost and implements highly efficient QCA structures. To verify the functionality of the proposed gate, some physical proofs, truth table and computational simulation results are performed. These results assured the validity of the existence of the proposed gate. It also dissipates less energy which has been calculated under three separate tunnelling energy levels using the QCAPro tool. To prove the effectiveness of the proposed MMV gate, several optimal irreversible arithmetic circuits such as three-input XOR, half-adder and full-adder are proposed. The modular layouts are verified with the freely available QCADesigner tool version 2.0.3.     

Self-activated ‘green’ carbon nanoparticles for symmetric solid-state supercapacitors

Tuning of porosity and surface properties of nanoparticles especially on carbon-based nanomaterials, adopting a ‘greener’ or self-activation synthesis technique for electrical charge storage, is progressing. Herein, we report the self-activation of Teak wood sawdust in a nitrogen atmosphere at different activation temperatures to synthesize carbon nanoparticles. The activated carbon nanoparticles synthesized at 900 °C exhibits a maximum?~?360 m² g^?1 surface area with?~?2 nm average pore size diameter. Five electrolytes viz. KOH, KCl, Na₂SO₄, NaCl, and H₃PO₄ are used for studying the supercapacitance nature of the activated carbon nanoparticles in a 3-electrode configuration. A maximum specific capacitance of?~?208 F g^?1 @ 0.25 A g^?1 is obtained in 1 M KOH as the electrolyte. Two symmetric supercapacitors, aqueous (1 M KOH) and solid-state (PVA/KOH), are fabricated, and their performance difference is compiled. The solid-state symmetric supercapacitor performs in a wider voltage window (1.7 V) with a superior energy density of 27.1 Wh kg^?1 at a power density of 178 W kg^?1.

Graphical abstract

     

Direct Observation of Worm‐Like Nanochannels and Emergent Magnon Motifs in Artificial Ferromagnetic Quasicrystals

Quasicrystalline structures and aperiodic metamaterials find applications ranging from established consumer gadgets to potential high‐tech photonic components owing to both complex arrangements of constituents and exotic rotational symmetries. Magnonics is an evolving branch of magnetism research where information is transported via magnetization oscillations (magnons). Their control and manipulation are so far best accomplished in periodic metamaterials which exhibit properties artificially modulated on the nanoscale. They give rise to functional components, such as band stop filters, magnonic transistors and nanograting couplers. Here, spin‐wave excitations in artificial ferromagnetic quasicrystals created via aperiodic arrangement of nanoholes are studied experimentally. Their ten‐fold rotational symmetry results in multiplexed magnonic nanochannels, suggesting a width down to 50 nm inside a so‐called Conway worm. Key elements of design are emergent magnon motifs and the worm‐like features which are scale‐invariant and not present in the periodic metamaterials. By imaging wavefronts in quasicrystals, insight is gained into how the discovered features materialize as a dense wavelength division multiplexer.     

Experimental analysis of the thermal properties of fused quartz-reinforced Al-6061alloy matrix composites using RSM approach

Journal of Mechanical Science and Technology - This study investigates the thermal property of fused quartz-reinforced aluminum 6061 alloy metal matrix composites for three different chill material...     

Utilization of secret sharing technology for secure communication: a state-of-the-art review

Multimedia Tools and Applications - Cryptography is the process by which a readable message is converted into cipher-text unintelligible to an eavesdropper. With the advent of the internet,...     

Compressive cyclic response of PEM fuel cell gas diffusion media

The fuel cell gas diffusion media (GDM) is a highly porous carbon-fiber-reinforced thin composite layer. The experimental response of these materials is observed to be highly nonlinear at low-stress levels. The cyclic mechanical response of GDM is investigated in terms of stiffness and damage parameters. The prediction of the state of deformation in GDM is vital in relating GDM's properties to ohmic and transport losses. To this end, a compressible form of the phenomenological model is proposed to capture the experimental cyclic response accurately. The model is constituent dependent; that is, the cumulative cyclic stress-strain response of GDM is a function of individual constituent phases present in the material. These individual constituents are porous matrix and reinforced fibers. The model hence derived for a typical GDM material, can predict residual strain, hysteresis, and damage quotient associated with the stress softening. This advanced model is implemented in the numerical domain to evaluate the response of the polymer electrolyte fuel cell (PEFC) unit cell. The stress-strain distribution fields are analyzed and compared with those of conventional GDM models. The results point to a remarkable deviation from the conventional notion of structural analysis.     

Localization of isotropic and anisotropic wireless sensor networks in 2D and 3D fields

Telecommunication Systems - Internet of Things (IoT) has changed the way people live by transforming everything into smart systems. Wireless Sensor Network (WSN) forms an important part of IoT....     

Nanoarchitectonics of hierarchical PbS material for all-solid-state asymmetric supercapacitor

Journal of Materials Science: Materials in Electronics - Present article reports morphology controlled synthesis of lead sulfide (PbS) thin films using cost-effective chemical method. The...