Algorithms for Handling the Fill Area Primitive of GKS

The fill area primitive of GKS (Graphical Kernel System)¹ is one of the more powerful features which differentiates it from earlier device independent graphics software and systems. Its specification is extremely general in the form of a closed boundary, possibly self-intersecting, and whose interior can be filled in a variety of styles. However a complete implementation of this primitive is very complex. It is difficult to find a single graphics workstation incorporating this primitive in hardware or firmware. Most GKS implementations will have to include software for simulating the appearance of this primitive on the commonly available displays and hard-copy graphics devices. Correct and efficient algorithms are necessary for developing this software. Because of the generality many of the existing algorithms are not directly applicable. In this paper we describe:
1. a new algorithm for clipping a fill area polygon, using what we have named as the Bridge Technique.
2. implementation of a plane sweep algorithm, by Nievergelt and Preparata,² for solid filling and hatching, particularly applicable to vector devices.
3. extension of the plane sweep algorithm for filling with any given pattern on raster as well as vector devices.
The algorithms have been designed to work for all special cases as well. In fact they have been implemented having in mind the fill area set primitive of GKS-3D extension.³ All these algorithms have been very successfully implemented in a commercially available GKS implementation, namely indoGKS.     

An Optimum Transmission Distance and Adaptive Clustering Based Routing Protocol for Cognitive Radio Sensor Network

Wireless Personal Communications - Adaptive transmission strategies for cognitive radio sensor network provide flexibility to the nodes based on data packets. In this paper, an optimum transmission...     

Switching Transient Analysis and Characterization of an E-Mode B-Doped GaN-Capped AlGaN DH-HEMT with a Freewheeling Schottky Barrier Diode (SBD)

Journal of Electronic Materials - This paper presents a systematic study of Al0.23Ga0.77N/GaN/AlxGa1?xN double-heterojunction high-electron-mobility transistors (DH-HEMTs) with a boron-doped...     

Sharing Political Content in Online Social Media: A Planned and Unplanned Behaviour Approach

Human’s decision making is not necessarily always planned; their unplanned behaviour—determined by natural personality traits—also contributes to the decision making process. In this study, we investigate factors related to planned and unplanned behaviour to understand why people share political content in online social media. Based on an online survey of 257 social media users, our results demonstrate that the factors representing both planned (i.e., perceived social recognition and altruistic motivation) and unplanned behaviour (i.e., extroversion and impulsiveness) affect people’s political content sharing behaviour. Our study understands that sharing political content is not like sharing other forms of content such as tourist attractions—the former can provoke serious punishment in some countries. Accordingly, trait impulsiveness is negatively associated with political content sharing behaviour. We also found that collective opinion moderates people’s planned behaviour, but not their unplanned behaviour. In other words, personality traits are unaffected by others’ opinions, but traits that humans can control can be shaped by others’.     

An efficient edge extraction approach for flame image analysis

In this paper, a simple and robust approach for flame and fire image analysis is proposed. It is based on the local binary patterns, double thresholding and Levenberg–Marquardt optimization technique. The presented algorithm detects the sharp edges and removes the noise and irrelevant artifacts. The autoadaptive nature of the algorithm ensures the primary edges of the flame and fire are identified in the different conditions. Moreover, a graphical approach is presented which can be used to calculate the combustion furnace flame temperature. The various experimentations are carried out on synthetic as well as real flame and fire images which validate the efficacy and robustness of the proposed approach.     

A Superconducting Dual‐Channel Photonic Switch

The mechanism of Cooper pair formation and its underlying physics has long occupied the investigation into high temperature (high‐T_c) cuprate superconductors. One of the ways to unravel this is to observe the ultrafast response present in the charge carrier dynamics of a photoexcited specimen. This results in an interesting approach to exploit the dissipation‐less dynamic features of superconductors to be utilized for designing high‐performance active subwavelength photonic devices with extremely low‐loss operation. Here, dual‐channel, ultrafast, all‐optical switching and modulation between the resistive and the superconducting quantum mechanical phase is experimentally demonstrated. The ultrafast phase switching is demonstrated via modulation of sharp Fano resonance of a high‐T_c yttrium barium copper oxide (YBCO) superconducting metamaterial device. Upon photoexcitation by femtosecond light pulses, the ultrasensitive cuprate superconductor undergoes dual dissociation–relaxation dynamics, with restoration of superconductivity within a cycle, and thereby establishes the existence of dual switching windows within a timescale of 80 ps. Pathways are explored to engineer the secondary dissociation channel which provides unprecedented control over the switching speed. Most importantly, the results envision new ways to accomplish low‐loss, ultrafast, and ultrasensitive dual‐channel switching applications that are inaccessible through conventional metallic and dielectric based metamaterials.     

Performance investigations on optimum mechanical design aspects of planar parallel manipulators

This paper presents a comparative analysis of three degrees of freedom planar parallel robotic manipulators (x, y and θ_z motion platforms) namely 2PRP-PPR, 2PRR-PPR, 3PPR (Hybrid), 3PRP (Hephaist) and 3PPR U-base in terms of optimal kinematic design performance, static structural stiffness and dynamic performance (energy and power consumption). Kinematic and dynamic performance analyses of these platforms have been done using multibody dynamics software (namely ADAMS/View). Static stiffness of the above-mentioned manipulators have been analysed, compared using the conventional joint space Jacobian stiffness matrix method, and this method has been verified through a standard finite-element software (namely NASTRAN) as well. The size of the fixed base or aspect ratio (width/height) can be varied for various working conditions to understand its design parameters and optimal design aspects which are depending on the fixed base structure. Different aspect ratios (fixed base size) are considered for the comparative analyses of isotropy, manipulability and stiffness for the above-mentioned planar parallel manipulators. From the numerical simulation results, it is observed that the 2PRP-PPR manipulator is associated with a few favourable optimum design aspects such as singularity-free workspace, better manipulability, isotropy, higher stiffness and better dynamic performance in terms of power and energy requirement as compared to other planar parallel manipulators.     

Analytical modelling and electrical characterisation of ZnO based HEMTs

Conventionally, Poisson’s equation coupled with 1-D Schrödinger’s equation is solved self-consistently in the triangular quantum well to calculate 2DEG density at the heterointerface. 2DEG density hence derived is a complicated transcendental function which cannot be solved analytically. Therefore, in this work, we use a simple expression for Fermi energy level to develop a compact physics-based 2D-analytical model for 2DEG density. The calculated 2DEG density from this model is validated with earlier reported experimental results. Using this 2DEG density, an expression for I-V characteristics of HEMTs has also been developed. The I-V characteristics of a buffer layer engineered MgZnO/CdZnO HEMT for improved 2DEG density have been analysed for the first time using developed model to the best of our knowledge.     

A conceptual framework for the adoption of big data analytics by e-commerce startups: a case-based approach

Information Systems and e-Business Management - E-commerce start-ups have ventured into emerging economies and are growing at a significantly faster pace. Big data has acted like a catalyst in...     

An automatic speech recognition system for spontaneous Punjabi speech corpus

Automatic speech recognition is the central part of the wheel towards the natural person-to-machine interaction technique. Due to the high disparity of speaking styles, speech recognition surely demands composite methods to constitute this irregularity. A speech recognition method can work in numerous distinct states such as speaker dependent/independent speech, isolated/continuous/spontaneous speech recognition, for less to very large vocabulary. The Punjabi language is being spoken by concerning 104 million peoples in India, Pakistan and other countries with Punjabi migrants. The Punjabi language is written in Gurmukhi writing in Indian Punjab, while in Shahmukhi writing in Pakistani Punjab. In the paper, the objective is to build the speaker independent automatic spontaneous speech recognition system for the Punjabi language. The system is also capable to recognize the spontaneous Punjabi live speech. So far, no work has to be achieved in the area of spontaneous speech recognition system for the Punjabi language. The user interfaces for Punjabi live speech system is created by using the java programming. Till now, automatic speech system is trained with 6012 Punjabi words and 1433 Punjabi sentences. The performance measured in terms of recognition accuracy which is 93.79% for Punjabi words and 90.8% for Punjabi sentences.