Design and implementation of generalized topologies of time-interleaved variable bandpass Σ−Δ modulators

In this thesis, novel analog-to-digital and digital-to-analog generalized time-interleaved variable bandpass sigma-delta modulators are designed, analysed, evaluated and implemented that are suitable for high performance data conversion for a broad-spectrum of applications. These generalized time-interleaved variable bandpass sigma-delta modulators can perform noise-shaping for any centre frequency from DC to Nyquist. The proposed topologies are well-suited for Butterworth, Chebyshev, inverse-Chebyshev and elliptical filters, where designers have the flexibility of specifying the centre frequency, bandwidth as well as the passband and stopband attenuation parameters. The application of the time-interleaving approach, in combination with these bandpass loop-filters, not only overcomes the limitations that are associated with conventional and mid-band resonator-based bandpass sigma-delta modulators, but also offers an elegant means to increase the conversion bandwidth, thereby relaxing the need to use faster or higher-order sigma-delta modulators. A step-by-step design technique has been developed for the design of time-interleaved variable bandpass sigma-delta modulators. Using this technique, an assortment of lower- and higher-order single- and multi-path generalized A/D variable bandpass sigma-delta modulators were designed, evaluated and compared in terms of their signal-to-noise ratios, hardware complexity, stability, tonality and sensitivity for ideal and non-ideal topologies. Extensive behavioural-level simulations verified that one of the proposed topologies not only used fewer coefficients but also exhibited greater robustness to non-idealties. Furthermore, second-, fourth- and sixth-order single- and multi-path digital variable bandpass digital sigma-delta modulators are designed using this technique. The mathematical modelling and evaluation of tones caused by the finite wordlengths of these digital multi-path sigmadelta modulators, when excited by sinusoidal input signals, are also derived from first principles and verified using simulation and experimental results. The fourth-order digital variable-band sigma-delta modulator topologies are implemented in VHDL and synthesized on Xilinx® SpartanTM-3 Development Kit using fixed-point arithmetic. Circuit outputs were taken via RS232 connection provided on the FPGA board and evaluated using MATLAB routines developed by the author. These routines included the decimation process as well. The experiments undertaken by the author further validated the design methodology presented in the work. In addition, a novel tunable and reconfigurable second-order variable bandpass sigma-delta modulator has been designed and evaluated at the behavioural-level. This topology offers a flexible set of choices for designers and can operate either in single- or dual-mode enabling multi-band implementations on a single digital variable bandpass sigma-delta modulator. This work is also supported by a novel user-friendly design and evaluation tool that has been developed in MATLAB/Simulink that can speed-up the design, evaluation and comparison of analog and digital single-stage and time-interleaved variable bandpass sigma-delta modulators. This tool enables the user to specify the conversion type, topology, loop-filter type, path number and oversampling ratio.

Consumers' willingness to pay for ethical attributes

Purpose: In recent years, there has been a big increase in the use of ethical attributes as marketing appeals. This paper examines consumers’ willingness to pay for three selected ethical attributes, namely ‘Organic’, ‘Recyclable Packaging’ and ‘Fairtrade’ in monetary terms. Design/Methodology/Approach: A modified choice-based experimental design with manipulation of the key constructs was used to estimate the mean value of how much consumers are willing to pay for the selected attributes attached to a box of premium chocolates. The results are based on the responses of a total of 208 consumers. Findings: Of the three attributes, ‘Recyclable Packaging’ has the strongest influence on the purchase decision, although this attribute generates the least additional value. The aggregated result shows that although consumers are willing to pay more for the product with ethical attributes than the one that is without, still around a half of them are not willing to pay more. In terms of demographics, the results show no significant differences between the two genders or different age groups in their willingness to pay for ethical attributes. As might be expected, willingness to pay was correlated with the level of consciousness of the ethical attributes. Originality/Value: The findings of this study help management to think practically about the value consumers willing to pay for the selected attributes. The results show a significant synergy in a combination of ethical attributes in products.

Visual Approaches to Property Law Pedagogy

Purpose - To consider a more visual approach to property law teaching practices. This will be achieved by exploring the existence of ‘visual learners’ as a student body, evaluating the use of more visual teaching techniques in academic practice, recognising the historic dominance of text in legal education, and examining the potential for heightening visual teaching practices in the teaching of property law. Design/methodology/approach – The paper reviews and analyses some of the available literature on visual pedagogy, and visual approaches to legal education, but also introduces an amount of academic practitioner analysis. Findings – This paper evidences that, rather than focusing on the categorisation of ‘visual learner’, the modern academic practitioner should employ the customary use of more visual stimuli; consequently becoming a more ‘visual teacher’. This paper demonstrates that these practices, if performed effectively, can impact upon the information literacy of the whole student body: It also proffers a number of suggestions as to how this could be achieved within property law teaching practices. Practical implications – The paper will provide support for early-career academic practitioners, who are entering a teaching profession in a period of accelerated and continual change, by presenting an overview of pedagogic practices in the area. It will also provide a stimulus for those currently teaching on property law modules and support their transition to a more visual form of teaching practice. Originality/value – This paper provides a comprehensive overview of visual pedagogy in legal education, and specifically within that of property law, which has not been conducted elsewhere.

Board attributes that increase firm risk - evidence from the UK

Purpose – The aim of the paper is to identify the board attributes that significantly increase firm risk. The study aims to find if board size, percentage of non-executive directors, women on the board, a powerful CEO, equity ownership amongst executive board directors and institutional investor ownership, are associated with firm risk. This is the first study that examines which board attributes increase firm risk using a UK based sample. Design/methodology/approach – This empirical study collected secondary data from Bloomberg and Morningstar databases. The data sample is an unbalanced panel of 260 companies’ secondary data on FTSE 350 index in the UK, from 2005 to 2010. The data was statistically analysed using STATA. Findings – The study establishes the board attributes that were significantly related to firm risk. The results show that a board which can increase firm risk is one that is small in size,has high equity ownership amongst executive board directors and has high institutional investor ownership. Research limitations/implications – The governance culture and regulatory system in the UK is different from other countries. Since the data is a UK based sample, the results can lack generalisability. Practical implications – The results are useful for investors who invest in large firms, to have the knowledge about the board attributes that can increase firm risk. Regulators can also use the results to strengthen regulatory guidelines. Originality/value – This study fills the gap in knowledge in UK governance literature on the board attributes that can increase firm risk.

Global nation product equity depending on a level of cultural diffusion

Purpose This paper aims to propose the global nation product equity model (GNPE) to measure global consumers’ equity of a product that a country produces, especially a nation’s cultural products (i.e. culducts). The model also examines the significant difference of GNPE depending on a cultural diffusion level. GNPE model proposes that depending on the level of people’s recognition/acceptance/preference of a culture from another country (i.e. cultural diffusion level), the equity of a product from that country could be different in different countries. As variables that affect GNPE, global nation product equity in general, global nation product equity of a product category and nation cultural equity are included in the model. Design/methodology/approach To test the model, this study developed Hallyu (Korean cultural diffusion)-related Korean culducts and measured global consumers’ equity for the Korean culducts. In all, 351 surveys were collected from China, France, England and the USA. Findings The results show the significantly different equities and relationships among equities depending on the level of Hallyu diffusion in each country. Therefore, Korea is suggested to focus on different equities in different countries. Originality/value This research proposed a new model that extends the previous brand equity models to non-branded products (i.e. cultural products). This model proposed new variables that affect equity of a product mentioned above and suggests different equities to improve in different countries depending on their level of cultural diffusion. Also, this cross-cultural study suggests a direction of culduct design, distribution and promotion strategies in the global market.

Rethinking gossip and scandal in healthcare organizations

Purpose – The purpose of this viewpoint paper is to argue that gossip is a neglected aspect of organizational communication and knowledge, and an under-used management resource. Design/methodology/approach – The paper challenges mainstream managerial assumptions that gossip is trivial or tainted talk which should be discouraged in the workplace. Instead, gossip is re-framed at an organizational level of analysis, which provides the opportunity for relational knowledge about systemic failure and poor practice in healthcare to surface. Findings – Rather than simply viewing gossip as an individual behaviour and interpersonal process, it is claimed that organizational gossip is also a valuable early warning indicator of risk and failure in healthcare systems. There is potentially significant value in re-framing gossip as an aspect of organizational communication and knowledge. If attended to (rather than neglected or silenced) gossip can provide fresh insights into professional practice, decision-making and relational leadership. Originality/value – This paper offers a provocative challenge to mainstream health organization and management thinking about gossip in the workplace. It offers new ways of thinking to promote patient safety, and prevent the scandals that have plagued healthcare organizations in recent years.

Production systems and supplier selection: a multi-phase process model

Purpose: This paper presents a combined multi-phase supplier selection model. The process repeatedly revisits the criteria and sourcing decision as the development process continues. This enables a structured adoption of product and production system innovation from strategic suppliers, where previously the literature purely focuses on product innovation or cost reduction. Design/methodology/approach: The authors adopted an embedded researcher style, inductive, qualitative case study of an industrial supply cluster comprising a focal automotive company and its interaction with three different strategic stamping suppliers. Findings: Our contribution is the multi-phased production and product innovation process. This is an advance from traditional supplier selection and also an extension of ideas of supplier-located product development as it includes production system development, and complements the literature on working with strategic suppliers. Specifically, we explicitly articulate the previously unreported issue of whether a supplier chosen for its innovation capabilities at the start of the new product development process will also be the most appropriate supplier during the production system development phase, when an ability to work collaboratively may be the most important attribute, or in the large-scale production phase when an ability to manufacture at low unit cost may be most important. Originality/value: The paper identifies a multi-phase approach to tendering within a fixed body of strategic suppliers which seeks to identify the optimum technological and process decisions as well as the traditional supplier sourcing choice. These areas have not been combined before and generate a valuable approach for firms to adopt as well as for researchers to extend our understanding of a highly complex process.