Unsupervised image thresholding: hardware architecture and its usage for FPGA-SoC platform

ABSTRACT

Otsu’s global automatic image thresholding operation is used in various image processing applications. It needs computation of normalized cumulative histogram, mean and cumulative moments that are compute-intensive operations. In this paper, a custom architecture is presented for an efficient computation of Otsu’s algorithm along with its utilization as an intellectual property (IP) core in a field programmable gate array (FPGA) based system-on-chip (SoC) environment for the application of connected component analysis (CCA). A self-normalization technique is employed, where single-cycle, read–modify–write operations are performed with block random access memories (BRAMs) and digital signal processing (DSP)slices. The architecture is designed for 640 × 480 size of images that are captured by a high-resolution analouge camera and buffered in a DDR2 SDRAM of Xilinx ML-507 platform at 25.175 MHz clock frequency. The embedded PowerPC processor core is used to control the frame acquisition process. Experimental results on Virtex-5 xc5vfx70t FPGA device show that the architecture utilizes 1.4% slices, 2.7% BRAMs and 3.9% DSP48E slices. The total power consumption of the design is 1440.59 mW. The proposed architecture as an IP core is able to work in real-time with standard VGA resolution video and requires low computational resources.     

Application of quantum dot gate nonvolatile memory (QDNVM) in image segmentation

This paper presents the application of quantum dot gate nonvolatile memory (QDNVM) in image processing application. The charge accumulation in the gate region varies the threshold voltage of QDNVM, which can be used as a reference voltage source in a comparator circuit. A simplified comparator circuit can be implemented using the QDNVM. In this work, the use of QDNVM-based comparators in image processing specially image segmentation is demonstrated, which can be efficient in future image processing application.     

Nonvolatile Silicon Memory Using GeO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript>-Cladded Ge Quantum Dots Self-Assembled on SiO<Subscript>2</Subscript> and Lattice-Matched II–VI Tunnel Insulator

This paper presents fabrication and characterization of a quantum dot-based floating gate nonvolatile memory device with site-specific self-assembly of germanium oxide-cladded germanium (GeO _x -Ge) quantum dots on SiO₂ and ZnS/ZnMgS/ZnS (II–VI lattice-matched high-κ dielectric) tunnel insulator material. These monodispersed and individually cladded quantum dots have the potential to store charge uniformly in the floating gate and are well suited for nonvolatile memory applications.     

Non-uniform distributions of photonic bandgap microstripline structures

With the advent of planar photonic bandgap (PBG) materials different topologies of PBG structures have been proposed to improve the bandpass and band rejection performances of microwave signals. Conventional circular patterned PBGs have constraints in the broadband performance due to the high ripple heights in S-parameters. In this paper, we suggest two novel configurations with non-uniform dimensions of circular patterned PBG to improve the stopband bandwidth and the ripples. The dimensions of the circles are varied proportionally to the Binomial and Shebyshev polynomial distributions. The S-parameter performances with respect to frequencies have been presented. It is seen that Shebyshev distribution produce excellent performances by suppressing ripples and generating sharp cut-offs.     

Design and Implementation of Routing Algorithm to Enhance Network Lifetime in WBAN

Today’s era is the era of smart and remote applications exploiting advancement in sensors, cloud, Internet of things etc. Major application is in healthcare monitoring and support using wireless body area network (WBAN) in which sensor nodes sense vital physiological parameters and send to server through sink i.e. smart phone nowadays for seamless monitoring. The most significant issue in such applications is energy efficiency which leads to enhanced network life time that ensures uninterrupted seamless services. From source to sink data transmission may occur considering three different scenarios: source to sink single hop direct data transmission irrespective of in-between node distance, source to sink multi hop data transmission in which transmission range of source node is fixed at a threshold to find next forwarder node and transmission range of source node is incremented by affixed value until data gets transmitted to sink. In this work WBAN having different network configurations based on fixed or random positions of nodes have been simulated. Different scenarios with fixed and varying number of nodes are framed and simulated using MATLAB 2020a for performance evaluation of proposed algorithm in terms of energy consumption, network lifetime, path loss etc. due to data transmission from source to sink. Experimental results show that incremental approach is better than direct one in terms of energy consumption, path loss and network lifetime. While selecting transmission range of a source node, it is considered to keep Specific Absorption Rate (SAR) lower to reduce impact on human tissue.

     

Bond graph modeling of a railway truck on curved track

Rail vehicles become unstable beyond a critical speed because of speed dependant creep forces at the rail-wheel contact surface. There is a constant demand for improved rail vehicle model for design of high-speed vehicles, and track. Works available in the literature are based on models of trucks with various simplifying assumptions such as reduced degree of freedom, small displacements and without kinematic nonlinearities and inclination of the contact surface. In this paper an integrated bond graph model of a truck is developed for the first time without the aforementioned assumptions. It is found that truck dynamical behavior is significantly different from those found in the literature in some cases.     

Effect of alloying with zinc on SFE of aluminium by study of lattice imperfections in cold worked Al-Zn alloys

A detailed X-ray Fourier line shape analysis has been performed on three compositions of Al-Zn alloys viz. Al-3.55 wt% Zn, Al-14.7 wt% Zn and Al-19.3 wt% Zn infcc phase. It has been found that deformation stacking faults, both intrinsic ά and extrinsic α are absent in the cold worked state and twin fault β is found to be slightly present in the deformed lattice of the two initial compositions of the alloys. Similar to the effect of solute germanium and copper, respectively in Al-Ge and Al-Cu systems, hexagonal zinc also fails to impart faulting infcc Al-Zn system. This corroborates the fact that aluminium has high stacking fault energy.     

Study of electrically small printed chakra (wheel) antenna

A novel printed antenna configuration in the form of a chakra (wheel) is presented. The antenna has many design parameters, such as axle radius, rim radius, and shaft location, and exhibits a very low design frequency which is five times smaller than that of a regular circular microstrip patch antenna of the same size     

On capillary gravity-wave motion in two-layer fluids

Generalized expansion formulae for the velocity potentials associated with plane gravity-wave problems in the presence of surface tension and interfacial tension are derived in both the cases of finite and infinite water depths in two-layer fluids. As a part of the expansion formulae, orthogonal mode-coupling relations, associated with the eigenfunctions of the velocity potential, are derived. The dispersion relations are analyzed to determine the characteristics of the two propagating modes in the presence of surface and interfacial tension in both the cases of deep-water and shallow-water waves. The expansion formulae are then generalized to deal with boundary-value problems satisfying higher-order boundary conditions at the free surface and interface. As applications of the expansion formulae, the solutions associated with the source potential, forced oscillation and reflection of capillary–gravity waves in the presence of interfacial tension are derived.