Search

Image encryption is one of the sensitive areas used recently to save information over the Internet and confirms the security on a higher level. A new cryptosystem has been proposed for the encoding and decoding of images using sine map, chaotic tent map, and circulant matrices. The process involves three stages. The sine map is used for the permutation phase. In the substitution phase, the Hill cipher method together with prime circulant matrix are used and a chaotic tent map is used in the diffusion phase. The algorithm becomes impenetrable to resist differential- and statistical-type attacks. The algorithm's key space is sufficient in size to withstand brute-force attacks. This symmetric image encryption algorithm indicates good results for correlation analysis, key space analysis, entropy analysis, key sensitivity analysis, histogram analysis, number of pixel change rate (NPCR), unified average changing intensity (UACI), and peak signal-to-noise ratio (PSNR). From all these simulation results, we come to know that the constructed image encryption cryptosystem is systematic and vigorous, supplying better protection for image encryption. [ABSTRACT FROM AUTHOR]

Summary: In recent 20 years, electronic equipment has been developing rapidly in the direction of light, miniaturization, flexibility, and integration. It is urgent to meet the needs of matching energy supply system to solve the practical application requirements in the fields of intelligent communication and mobile medical treatment. Electroactive polymers (EAPs) are recommendable material for manifesting muscle‐like actuation. The dielectric elastomers (DEs) obtained from the EAPs are quite capable of inducing electrical energy and transmute it into mechanical energy. DEs are capacitors covered by an outer elastic membrane, sandwiched between the two docile electrodes. In the beginning, for getting the efficient responses out of the DE actuators, the material requirements and electromechanical principal are applied. Viscoelastic damping, low dielectric loss, stretch ability, and dielectric permittivity are the desirable characteristics that we are expecting in a polymer. In the current research, we are going to adopt the sequential approach by describing the advances, challenges, and applications of DEAs in the coming future. [ABSTRACT FROM AUTHOR]

Summary: A novel configuration of humidification dehumidification (HDH) desalination system is presented using direct contact bubble column (BC) humidifier and dehumidifier. Experiments are carried out for performance analysis and comparison between a single‐stage, HDH air heated system (one humidifier and a dehumidifier) and a double‐stage HDH system (two BC humidifiers with air reheating). Effect of various operating parameters such as airflow rate, air temperature, and humidifier water levels is studied on performance metrics such as productivity, gain output ratio (GOR), input energy, specific energy consumption, and effectiveness. Results show that higher airflow rate, air temperature, and humidifier water level favor the system performance. The single‐stage system has a maximum productivity rate of 0.19 L/h and GOR of 0.21 obtained at 140°C and 1.5 standard cubic feet per minute (SCFM). However, the productivity of the single‐stage HDH system is limited due to low air outlet temperature at the exit of the BC humidifier. The double‐stage humidification system performs better in terms of productivity and GOR. The two‐stage humidification HDH system produced a distillate rate of 0.46 L/h and GOR of 0.4 with thermal energy increment of only 0.27 kW compared to the single‐stage system. The obtained results are promising in comparison with previous HDH studies, especially of air heated cycle. The estimated cost of production is 0.090 USD/L for double‐stage HDH BC. [ABSTRACT FROM AUTHOR]

ABSTRACT Wireless sensor networks (WSNs) are emerging as useful technology for information extraction from the surrounding environment by using numerous small-sized sensor nodes that are mostly deployed in sensitive, unattended, and (sometimes) hostile territories. Traditional cryptographic approaches are widely used to provide security in WSN. However, because of unattended and insecure deployment, a sensor node may be physically captured by an adversary who may acquire the underlying secret keys, or a subset thereof, to access the critical data and/or other nodes present in the network. Moreover, a node may not properly operate because of insufficient resources or problems in the network link. In recent years, the basic ideas of trust and reputation have been applied to WSNs to monitor the changing behaviors of nodes in a network. Several trust and reputation monitoring (TRM) systems have been proposed, to integrate the concepts of trust in networks as an additional security measure, and various surveys are conducted on the aforementioned system. However, the existing surveys lack a comprehensive discussion on trust application specific to the WSNs. This survey attempts to provide a thorough understanding of trust and reputation as well as their applications in the context of WSNs. The survey discusses the components required to build a TRM and the trust computation phases explained with a study of various security attacks. The study investigates the recent advances in TRMs and includes a concise comparison of various TRMs. Finally, a discussion on open issues and challenges in the implementation of trust-based systems is also presented. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Recent research trends in intelligent transportation system are focused toward developing automatic incident detection systems to deal with on-road incidents including accidents, traffic congestion, and jamming which cause damage to precious human lives and financial losses. Most of the existing automatic incident detection systems use fixed detectors to detect traffic parameters like occupancy, speed, and lane change information. These systems are prone to delay, inaccuracy, and false alarms during data collection and processing due to line of sight and short-range communication, weather conditions, road repairing, and driver's driving patterns. Moreover, these systems are designed for freeways/highways and are less compatible with city scenario due to its highly variable traffic density factor. To overcome these deficiencies, an effective and robust approach for automatic incident detection for smart city is developed using smart roads in association with roadside units for data collection and data processing, respectively. The incident confidence factor of the algorithm is based not only on speed and lane change parameters but also on acceleration, orientation, and deviation factors that are integrated to cope with peak/non-peak traffic hours. The integration of multiple parameters increases the incident belief factor and hence the accuracy of incident detection. The complete algorithm is mathematically described using the notions of set theory and then formal analysis assures that the algorithm would be less susceptible to runtime and logical errors during simulations. [ABSTRACT FROM AUTHOR]