Designing a secure designated server identity-based encryption with keyword search scheme: still unsolved

There exist only a few papers in the literature which target the problem of “proposing a secure designated server identity-based encryption with keyword search scheme.” In this paper, we prove that they all suffer from security issues, and therefore, this challenging problem still remains open.     

Fabrication of magnetic β-CD/chitosan nanocomposite as an efficient and recyclable dye adsorbent

ABSTRACT

In this work, novel magnetic nanocomposite adsorbents were prepared by crosslinking β-cyclodextrin (β-CD) onto chitosan backbones by using epichlorohydrin as a crosslinker and in the presence of Fe₃O₄ nanoparticles. The composition of β-CD-chitosan nanocomposites was characterized via FTIR, XRD, TEM, SEM, and VSM. Then, the as-prepared nanocomposites were treated for elimination of methyl orange (MO). The results indicated that the adsorption of MO exhibited a maximum adsorption capacity of 314 mg g^?1 at 25°C. Moreover, the rates and isotherm data of adsorption matched excellent at different MO concentrations (10, 60, and 120 mg/L) using second-order and Langmuir models with the regression coefficient (R²) of 0.9993 and 9990, respectively. Besides, the thermodynamic data confirmed MO adsorption as an endothermic process. The adsorbent was also confirmed as good materials for re-use and maintained 88% of its initial adsorption capacity for MO after the fifth regeneration cycles. In conclusion, the synthesized magnetic nanocomposites can be applied as cost-effective dye adsorbents with high regeneration efficiency.     

High-speed GPU implementation of a secret sharing scheme based on cellular automata

The Journal of Supercomputing - Parallel implementation provides a solution for the problem of accelerating cellular automata (CA)-based secret sharing schemes and make them appropriate for bulk...     

Predicting missing contacts in mobile social networks

Experimentally measured contact traces, such as those obtained in a conference setting by using short range wireless sensors, are usually limited with respect to the practical number of sensors that can be deployed as well as the number of available human volunteers. Moreover, most previous experiments in this field can report only partial contact information since not everyone participating in the experiment carries a sensor device. Previously collected contact traces have significantly contributed to the development of more realistic human mobility models. This in turn has influenced proposed routing algorithms for Delay Tolerant Networks where human contacts play a vital role in message delivery. By exploiting time-spatial properties of contact graphs as well as the popularity and social information of mobile nodes, we propose a novel method to reconstruct the missing parts of contact graphs where only a subset of nodes are able to sense contacts.     

The Electrochemical Behavior of Au/AuNPs/PNA/ZnSe-QD/ACA Electrode Towards CySH Oxidation

Nano-Micro Letters - This work describes the electrochemical behavior of azodicarboxamide (ACA) film immobilized on the surface of penicillamine (PNA)/ZnSe-quantum dot (ZnSe-QD) gold nanoparticle...     

Stability analysis in nuclear reactor using Lyapunov exponent

A simple model for nuclear reactor is proposed. With increasing the fuel concentration, our minimal model shows two successive phases; subcritical and supercritical. In subcritical regime, the neutron population grows with increasing the fuel concentration. In the supercritical state, the Lyapunov exponent is positive implying that the neutron diffusion phenomena are spatiotemporal chaos. In the present paper, the infinite multiplication factor curve is qualitatively reproduced for fuel concentration. We have derived the critical fuel concentration based on the Lyapunov exponents. The basic objective of the work is to improve the prediction of the critical neutron population with respect to the fuel concentration.     

Predicting roadheader performance by using artificial neural network

With growing use of roadheaders in the world and its significant role in the successful accomplishment of a tunneling project, it is a necessity to accurately predict performance of this machine in different ground conditions. On the other hand, the existence of some shortcomings in the prediction models has made it necessary to perform more research on the development of the new models. This paper makes an attempt to model the rate of roadheader performance based on the geotechnical and geological site conditions. For achieving the aim, an artificial neural network (ANN), a powerful tool for modeling and recognizing the sophisticated structures involved in data, is employed to model the relationship between the roadheader performance and the parameters influencing the tunneling operations with a high correlation. The database used in modeling is compiled from laboratory studies conducted at Azad University at Science and Research Branch, Tehran, Iran. A model with architecture 4-10-1 trained by back-propagation algorithm is found to be optimum. A multiple variable regression (MVR) analysis is also applied to compare performance of the neural network. The results demonstrate that predictive capability of the ANN model is better than that of the MVR model. It is concluded that roadheader performance could be accurately predicted as a function of unconfined compressive strength, Brazilian tensile strength, rock quality designation, and alpha angle R ² = 0.987. Sensitivity analysis reveals that the most effective parameter on roadheader performance is the unconfined compressive strength.     

Thermal Buckling of Imperfect Deep Functionally Graded Spherical Shell

Thermal buckling analysis of deep imperfect functionally graded (FGM) spherical shell is considered in this paper. A mixture of ceramic and metal is considered for the FGM shell and the material properties, such as the modulus of elasticity and coefficient of thermal expansion, vary by a power law function through the thickness. Employing the Sanders non-linear kinematic relations, total potential energy function is derived and the equilibrium and stability equations are obtained for the imperfect shell. Approximate solutions satisfying the simply supported boundary condition are assumed and using the Galerkin method the error due to the approximation is minimized. The geometrically imperfect shell is considered and three types of thermal loadings, such as the uniform temperature rise (UTR), linear temperature rise through the thickness (LTR), and non-linear temperature rise through the thickness (NLTR) are considered and their associated buckling temperatures are obtained. The effects of different temperature functions and the magnitude of initial geometric imperfection are examined on the thermal buckling loads of the shell.     

Cryptanalysis and improvement of a group RFID authentication protocol

Wireless Networks - In recent years, radio frequency identification (RFID) systems have become popular for identification. The key technology to protect the security of RFID systems is mutual...     

A generic construction to build simple oblivious transfer protocols from homomorphic encryption schemes

The Journal of Supercomputing - Oblivious transfer is a fundamental problem in cryptography where it is required that a sender transfers one of potentially many pieces of information to a receiver...