Physics and Applications of Laser Diode Chaos

An overview of chaos in laser diodes is provided which surveys experimental achievements in the area and explains the theory behind the phenomenon. The fundamental physics underpinning this behaviour and also the opportunities for harnessing laser diode chaos for potential applications are discussed. The availability and ease of operation of laser diodes, in a wide range of configurations, make them a convenient test-bed for exploring basic aspects of nonlinear and chaotic dynamics. It also makes them attractive for practical tasks, such as chaos-based secure communications and random number generation. Avenues for future research and development of chaotic laser diodes are also identified.Comment: Published in Nature Photonic

A Framework for Life Cycle Cost Estimation of a Product Family at the Early Stage of Product Development

A cost estimation method is required to estimate the life cycle cost of a product family at the early stage of product development in order to evaluate the product family design. There are difficulties with existing cost estimation techniques in estimating the life cycle cost for a product family at the early stage of product development. This paper proposes a framework that combines a knowledge based system and an activity based costing techniques in estimating the life cycle cost of a product family at the early stage of product development. The inputs of the framework are the product family structure and its sub function. The output of the framework is the life cycle cost of a product family that consists of all costs at each product family level and the costs of each product life cycle stage. The proposed framework provides a life cycle cost estimation tool for a product family at the early stage of product development using high level information as its input. The framework makes it possible to estimate the life cycle cost of various product family that use any types of product structure. It provides detailed information related to the activity and resource costs of both parts and products that can assist the designer in analyzing the cost of the product family design. In addition, it can reduce the required amount of information and time to construct the cost estimation system

Culture, demography and individuals' technology acceptance behaviour: A PLS based structural evaluation of an extended model of technology acceptance in South-Asian country context

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The models that predict the factors of individuals’ acceptance behaviour are predominantly based on a technology acceptance model (TAM) or the TAM’s conceptualisation. Although the TAM has a parsimonious structure and good explanatory power across the time, population and context, it is still criticised by a number of researchers. Categorically, it is criticised due to: inherent ‘cultural bias’ that limits its generalisability across cultures (national to organisational level); its underlying conceptualisation of predicting acceptance behaviour solely based on an ‘individual-based reactions’ that limits its applicability over the group’s effect (normative and social influence); and finally, due to its presupposition to examine the effect of ‘external variables’ through the only mediation effect of beliefs’ perceived ease of use (PEOU) and perceived usefulness (PU) that limits its ability to be extended beyond its boundaries by adding further factors directly or indirectly affecting intention behaviour (BI). To overcome mentioned limitations, an extended technology acceptance model to suit a developing country context is presented. The model attempted to delineate the direct relationship between behavioural beliefs, normative and control beliefs, management support beliefs, and task-specific beliefs towards acceptance intention and usage. In addition, the model examined the overlooked moderating impact of demographic and situational variables (age, gender, organisational type, academic position, educational level, experience usage and voluntariness) and cultural dimensions (masculinity-femininity, individualism-collectivism, power distance, and uncertainty avoidance) on indirect relations predicting acceptance behaviour. This study used a quantitative methodology to investigate the correlational paths. Using a cross-sectional survey method, data was collected from 504 academics working in 25 public and private higher educational institutions in Pakistan. Overall response rate was 53.9% (i.e. 504 out of 935). After data-screening, the final model was tested with 380 subjects. Hypothetical relationships were examined using structural equation modelling (SEM) based on the partial least squares (PLS) at the first stage, and with analysis of moment structures (AMOS) at the second stage. The indirect exploratory effect of the moderators was examined using multi-group analysis (MGA) method. The study findings indicate that the extended model achieved an acceptable fit with the data and most of the hypothetical paths were significant. Specifically, in the direct relationships, out of 20 paths representing 12 hypotheses, 11 were supported leaving 9 as unsupported. The highest variance explained by the independent variables towards dependent variables was quite similar in PU and BI (R2=26% in both using PLS; R2=34% in BI and 33% in PU using AMOS). The highest significant path was perception of usefulness, followed by academic tasks and resource facilitations towards intention; and perception of ease of use, subjective norms, and institute support towards perception of usefulness. The findings of moderating factors i.e., demographics revealed that subjects younger in age, female in gender and bachelor degree in education were influenced by the perception of ease of use, and normative beliefs; control beliefs were influenced by the organisation being private; management support at institute level was more influential in private organisations with mandatory settings; and the effect of perception of usefulness and normative beliefs was decreased with the increased experience. From the cultural perspective, the highly sensitive path was between normative beliefs and the perception of usefulness, so that the effect was stronger for subjects who were feminine in nature, collectivist in society, and high on power distance. Demographic factor academic-position and cultural dimension uncertainty avoidance did not produce any moderation effect. Finally, based on the findings, limitations and implications for theory and practices are devised.University of Sindh Jamshor

MS FT-2-2 7 Orthogonal polynomials and quadrature: Theory, computation, and applications

Quadrature rules find many applications in science and engineering. Their analysis is a classical area of applied mathematics and continues to attract considerable attention. This seminar brings together speakers with expertise in a large variety of quadrature rules. It is the aim of the seminar to provide an overview of recent developments in the analysis of quadrature rules. The computation of error estimates and novel applications also are described

Generalized averaged Gaussian quadrature and applications

A simple numerical method for constructing the optimal generalized averaged Gaussian quadrature formulas will be presented. These formulas exist in many cases in which real positive GaussKronrod formulas do not exist, and can be used as an adequate alternative in order to estimate the error of a Gaussian rule. We also investigate the conditions under which the optimal averaged Gaussian quadrature formulas and their truncated variants are internal