A Novel Algebraic Technique for the Construction of Strong Substitution Box

Magnetic induction applications mostly rely on resonance for inducing maximum magnetic fields to system loads and hence for each resonant frequency dedicated circuits are required. Unfortunately, the frequency responses of such inductive systems manifest several peaks (frequency splitting) when their coupling coefficients are equal to or larger than critical coupling. Such frequency responses with several peaks are detrimental when the objective is to transfer maximum energy. Frequency splitting between inductive coils have been seen to date as detrimental to wireless power transfer and inductive communication systems. In this paper it is demonstrated that frequency splitting is a welcome phenomenon with advantage in the design of inductive filter banks and multi-frequency inductive systems. The centre frequencies of the filter banks result from split bands of inductive systems. This phenomenon is applied in conjunction with an innovative recursive algorithm to design inductive filter banks. The filters straddle both sides of the resonant frequency position and can be resolved individually.     

Novel Approach of Key Predistribution for Grid Based Sensor Networks

Wireless Personal Communications - Grid based sensor networks are significant for applications such as monitoring goods in a warehouse, studying traffic level of city streets, monitoring energy...     

Square-Root-Domain Realization of Single-Cell Architecture of Complex TDCNN

Square-root-domain (SRD) CMOS analog realization of a single cell architecture of the complex Temporal Derivative Cellular Neural Networks (TDCNNs) is introduced in this paper. TDCNN initiates time derivative ‘diffusion’ between CNN cells for non-separable spatiotemporal filtering applications, where the input to the CNN is an image that changes over time. The evaluation of the performance of the complex SRD TDCNN cell has been done using the Cadence Orcad software with TSMC 0.18-μm CMOS process model parameters. The provided simulated results confirm the validity of the theory.     

Automatic segmentation of high-throughput RNAi fluorescent cellular images.

High-throughput genome-wide RNA interference (RNAi) screening is emerging as an essential tool to assist biologists in understanding complex cellular processes. The large number of images produced in each study make manual analysis intractable; hence, automatic cellular image analysis becomes an urgent need, where segmentation is the first and one of the most important steps. In this paper, a fully automatic method for segmentation of cells from genome-wide RNAi screening images is proposed. Nuclei are first extracted from the DNA channel by using a modified watershed algorithm. Cells are then extracted by modeling the interaction between them as well as combining both gradient and region information in the Actin and Rac channels. A new energy functional is formulated based on a novel interaction model for segmenting tightly clustered cells with significant intensity variance and specific phenotypes. The energy functional is minimized by using a multiphase level set method, which leads to a highly effective cell segmentation method. Promising experimental results demonstrate that automatic segmentation of high-throughput genome-wide multichannel screening can be achieved by using the proposed method, which may also be extended to other multichannel image segmentation problems.     

Information Processing and Wireless Energy Harvesting in Interference-Aware Public Safety Networks

In a public safety environment, user equipments (UEs) located within the coverage area of evolved NodeB, relay network services to out-of-coverage UEs. However, relay UEs in public safety environments are typically energy constrained and cannot operate indefinitely without recharging. Radio frequency energy harvesting has been proposed as a solution for recharging wireless UEs. In this paper, we propose a scheme for extending the lifetime of a public safety network by wirelessly charging relay UEs. In addition, we propose a relay selection method considering the battery status of relay UEs. The proposed relay selection is defined as a bipartite graph matching problem and the optimal relay is obtained through matching games technique. The proposed scheme not only improves the network lifetime but also extend the network coverage. We also conduct system level simulations to evaluate the performance of the proposed scheme. Simulation results show that the overall performance of the system is improved in terms of achievable throughput and network lifetime.     

Versatile voltage-mode universal biquad filter using the operational amplifier pole

A new multifunction voltage-mode biquad filter topology having three inputs and one output is described. The filter consists of a single operational amplifier (OA), a single capacitor, and two resistors and supports LP, BP, HP, AP and Notch filtering signals from the same topology, without requiring additional components besides being devoid of component matching constraints. The filter uses OA pole and has thereby acquired suitability for extended frequency operation. The natural angular frequency ω₀ and the Q can be separately tuned. The circuit has low sensitivity figures. PSPICE simulation results are employed to verify the circuit performance.     

Jamming Skins that Control System Rigidity from the Surface

Numerous animals adapt their stiffness during natural motions to increase efficiency or environmental adaptability. For example, octopuses stiffen their tentacles to increase efficiency during reaching, and several species adjust their leg stiffness to maintain stability when running across varied terrain. Inspired by nature, variable-stiffness machines can switch between rigid and soft states. However, existing variable-stiffness systems are usually purpose-built for a particular application and lack universal adaptability. Here, reconfigurable stiffness-changing skins that can stretch and fold to create 3D structures or attach to the surface of objects to influence their rigidity are presented. These “jamming skins” employ vacuum-powered jamming of interleaved, discrete planar elements, enabling 2D stretchability of the skin in its soft state. Stretching allows jamming skins to be reversibly shaped into load-bearing, functional tools on-demand. Additionally, they can be attached to host structures with complex curvatures, such as robot arms and portions of the human body, to provide support or create a mold. We also show how multiple skins can work together to modify the workspace of a continuum robot by creating instantaneous joints. Jamming skins thus serve as a reconfigurable approach to creating tools and adapting structural rigidity on-demand.     

DC and RF performance of GaAs MESFET fabricated on silicon substrate using epitaxial lift-off technique

GaAs MESFETs have been fabricated on a silicon substrate using a molecular beam epitaxy grown film detached from its growth substrate and attached on a silicon substrate covered with a dielectric. The device processing is done on the silicon substrate. The MESFETs exhibit I/sub DSS/=130 mA/mm, g/sub m/=135 mS/mm and for 1.3 mu m gate length unity current gain cut-off frequency f/sub T/ of 12 GHz. Excellent device isolation with subpicoampere leakage currents is obtained.<>     

A 100-MHz 64-tap FIR digital filter in 0.8-μm BiCMOS gate array

A 64-tap FIR (finite impulse response) digital filter that has been designed using a newly developed filter compiler and fabricated in a 0.8-μm triple-level interconnect BiCMOS gate array technology is presented. The filter has been tested and is fully functional at a 100-MHz clock rate. These results are obtained by combining an optimized architecture and gate array floorplan with submicrometer BiCMOS technology. The filter occupies 49 mm², which is approximately two-thirds of the 100 K gate array core. The design uses an equivalent of 55 K gates (two-input NAND gates). The device input/output are 100 K emitter-coupled-logic (ECL) compatible     

Patient-specific bronchoscopy visualization through BRDF estimation and disocclusion correction

This paper presents an image-based method for virtual bronchoscope with photo-realistic rendering. The technique is based on recovering bidirectional reflectance distribution function (BRDF) parameters in an environment where the choice of viewing positions, directions, and illumination conditions are restricted. Video images of bronchoscopy examinations are combined with patient-specific three-dimensional (3-D) computed tomography data through two-dimensional (2-D)/3-D registration and shading model parameters are then recovered by exploiting the restricted lighting configurations imposed by the bronchoscope. With the proposed technique, the recovered BRDF is used to predict the expected shading intensity, allowing a texture map independent of lighting conditions to be extracted from each video frame. To correct for disocclusion artefacts, statistical texture synthesis was used to recreate the missing areas. New views not present in the original bronchoscopy video are rendered by evaluating the BRDF with different viewing and illumination parameters. This allows free navigation of the acquired 3-D model with enhanced photo-realism. To assess the practical value of the proposed technique, a detailed visual scoring that involves both real and rendered bronchoscope images is conducted.