Fokker-Planck equation approach to the description of soliton statistics in optical fiber transmission systems

We derive rigorously the Fokker-Planck equation that governs the statistics of soliton parameters in optical transmission lines in the presence of additive amplifier spontaneous emission. We demonstrate that these statistics are generally non-Gaussian. We present exact marginal probability-density functions for soliton parameters for some cases. A WKB approach is applied to describe the tails of the probability-density functions. © 2005 Optical Society of America.

The application of physiological observation methods to emotion research

Purpose - The purpose of this paper is to examine consumer emotions and the social science and observation measures that can be utilised to capture the emotional experiences of consumers. The paper is not setting out to solve the theoretical debate surrounding emotion research, rather to provide an assessment of methodological options available to researchers to aid their investigation into both the structure and content of the consumer emotional experience, acknowledging both the conscious and subconscious elements of that experience. Design/methodology/approach - A review of a wide range of prior research from the fields of marketing, consumer behaviour, psychology and neuroscience are examined to identify the different observation methods available to marketing researchers in the study of consumer emotion. This review also considers the self report measures available to researchers and identifies the main theoretical debates concerning emotion to provide a comprehensive overview of the issues surrounding the capture of emotional responses in a marketing context and to highlight the benefits that observation methods offer this area of research. Findings - This paper evaluates three observation methods and four widely used self report measures of emotion used in a marketing context. Whilst it is recognised that marketers have shown preference for the use of self report measures in prior research, mainly due to ease of implementation, it is posited that the benefits of observation methodology and the wealth of data that can be obtained using such methods can compliment prior research. In addition, the use of observation methods cannot only enhance our understanding of the consumer emotion experience but also enable us to collaborate with researchers from other fields in order to make progress in understanding emotion. Originality/value - This paper brings perspectives and methods together to provide an up to date consideration of emotion research for marketers. In order to generate valuable research in this area there is an identified need for discussion and implementation of the observation techniques available to marketing researchers working in this field. An evaluation of a variety of methods is undertaken as a point to start discussion or consideration of different observation techniques and how they can be utilised.

Survey and applications of standardized energy metrics to mobile networks

The energy consumption and the energy efficiency have become very important issue in optimizing the current as well as in designing the future telecommunications networks. The energy and power metrics are being introduced in order to enable assessment and comparison of the energy consumption and power efficiency of the telecommunications networks and other transmission equipment. The standardization of the energy and power metrics is a significant ongoing activity aiming to define the baseline energy and power metrics for the telecommunications systems. This article provides an up-to-date overview of the energy and power metrics being proposed by the various standardization bodies and subsequently adopted worldwide by the equipment manufacturers and the network operators. © Institut Télécom and Springer-Verlag 2012.and Springer-Verlag 2012.

Ocular changes and other factors relating to two forms of contact lenses:a comparative study

The work utilising a new material for contact lenses has fallen into three parts: Physioloeical considerations: Since the cornea is devoid of blood vessels, its oxygen is derived from the atmosphere. Early hydrophilic gel contact lenses interrupted the flow of oxygen and corneal insult resulted. Three techniques of fenestration were tried to overcome this problem. High speed drilling with 0.1 mm diameter twist drills. was found to be mechanically successful, but under clinical conditions mucous blockage of the fenestrations occurred. An investigation was made into the amount of oxygen arriving at the corneal interface; related to gel lens thickness. The results indicated an improvement in corneal oxygen as lens thickness was reduced. The mechanism is thought to be a form of mechanical pump. A series of clinical studies con:firmed the experimental work; the use of thin lenses removing the symptoms of corneal hypoxia. Design: The parameters of lens back curvature. lens thickness and lens diameter have been isolated and related to three criteria of vision (a) Visual acuity. (b) Visual stability and (c) Induced astigmatism. From the results achieved a revised and basically successful design of lens has been developed. Comparative study: The developed form of lens was compared with traditional lenses in a controlled survey. Twelve factors were assessed over a twenty week period of wear using a total of eighty four patients. The results of this study indicate that whilst the expected changes were noted with the traditional lens wearers, gel lens wearers showed no discernible change in any of the factors measured. ldth the exception of' one parameter. In addition to a description of' the completed l'iork. further investigations are ·sug~ested l'lhich. it is hoped. l'iould further improve the optical performance of gel lenses.

Collocation:applications and implications

All aspects of the concept of collocation – the phenomenon whereby words naturally tend to occur in the company of a restricted set of other words – are covered in this book. It deals in detail with the history of the word collocation, the concepts associated with it and its use in a linguistic context. The authors show the practical means by which the collocational behaviour of words can be explored using illustrative computer programs and examine applications in teaching, lexicography and natural language processing that use collocation in formation. The book investigates the place that collocation occupies in theories of language and provides a thoroughly comprehensive and up-to-date survey of the current position of collocation in language studies and applied linguistics. This text presents a comprehensive description of collocation, covering both the theoretical and practical background and the implications and applications of the concept as language model and analytical tool. It provides a definitive survey of currently available techniques and a detailed description of their implementation.

The measurement and decomposition of economy-wide productivity growth:Assessing the accuracy and selecting between different approaches

Productivity at the macro level is a complex concept but also arguably the most appropriate measure of economic welfare. Currently, there is limited research available on the various approaches that can be used to measure it and especially on the relative accuracy of said approaches. This thesis has two main objectives: firstly, to detail some of the most common productivity measurement approaches and assess their accuracy under a number of conditions and secondly, to present an up-to-date application of productivity measurement and provide some guidance on selecting between sometimes conflicting productivity estimates. With regards to the first objective, the thesis provides a discussion on the issues specific to macro-level productivity measurement and on the strengths and weaknesses of the three main types of approaches available, namely index-number approaches (represented by Growth Accounting), non-parametric distance functions (DEA-based Malmquist indices) and parametric production functions (COLS- and SFA-based Malmquist indices). The accuracy of these approaches is assessed through simulation analysis, which provided some interesting findings. Probably the most important were that deterministic approaches are quite accurate even when the data is moderately noisy, that no approaches were accurate when noise was more extensive, that functional form misspecification has a severe negative effect in the accuracy of the parametric approaches and finally that increased volatility in inputs and prices from one period to the next adversely affects all approaches examined. The application was based on the EU KLEMS (2008) dataset and revealed that the different approaches do in fact result in different productivity change estimates, at least for some of the countries assessed. To assist researchers in selecting between conflicting estimates, a new, three step selection framework is proposed, based on findings of simulation analyses and established diagnostics/indicators. An application of this framework is also provided, based on the EU KLEMS dataset.

Social sustainability initiatives in cocoa supply chains in Africa:an analysis of sustainability reporting of world's major chocolatiers

This research paper focuses on the self-declared initiatives of the four largest chocolate companies to tackle social problems within the context of establishing a sustainable supply chain. After the literature review of sustainability, supply chain management, and cocoa farming, this paper gives an assessment of the extant practices of the chocolatiers and makes a comparative analysis based on Corporate Social Responsibility (CSR) and Sustainability Reports. This paper uses a case study approach based on secondary-data. A roadmap and benchmarking of social sustainability initiatives were conducted for the supply chain management activities of the world's four largest chocolatiers. This paper analyses the extant sustainability practices of the chocolatiers and offers a model framework for comparison of the measures taken. This paper is based on self-declared secondary data. There is a chance that some practices were not documented by the case companies; or that companies claim what they don't actually do. This paper provides a framework for agricultural businesses to compare their sustainability efforts and improve the performance of their supply chains. Originality and value of this research reside in terms of both literature and methodology. The framework for analysing the social sustainability aspects of agricultural supply chains is original and gives an up-to-date view of sustainability practices. The use of secondary data to compare self-declared initiatives is also a novel approach to business sustainability research.

Green operations initiatives in the automotive industry:an environmental reports analysis and benchmarking study

Purpose: The purpose of this paper is to focus on investigating and benchmarking green operations initiatives in the automotive industry documented in the environmental reports of selected companies. The investigation roadmaps the main environmental initiatives taken by the world's three major car manufacturers and benchmarks them against each other. The categorisation of green operations initiatives that is provided in the paper can also help companies in other sectors to evaluate their green practices. Design/methodology/approach: The first part of the paper is based on existing literature on the topic of green and sustainable operations and the "unsustainable" context of automotive production. The second part relates to the roadmap and benchmarking of green operations initiatives based on an analysis of secondary data from the automotive industry. Findings: The findings show that the world's three major car manufacturers are pursuing various environmental initiatives involving the following green operations practices: green buildings, eco-design, green supply chains, green manufacturing, reverse logistics and innovation. Research limitations/implications: The limitations of this paper start from its selection of the companies, which was made using production volume and country of origin as the principal criteria. There is ample evidence that other, smaller, companies are pursuing more sophisticated and original environmental initiatives. Also, there might be a gap between what companies say they do in their environmental reports and what they actually do. Practical implications: This paper helps practitioners in the automotive industry to benchmark themselves against the major volume manufacturers in three different continents. Practitioners from other industries will also find it valuable to discover how the automotive industry is pursuing environmental initiatives beyond manufacturing, apart from the green operations practices covering broadly all the activities of operations function. Originality/value: The originality of the paper is in its up-to-date analysis of environmental reports of automotive companies. The paper offers value for researchers and practitioners due to its contribution to the green operations literature. For instance, the inclusion of green buildings as part of green operations practices has so far been neglected by most researchers and authors in the field of green and sustainable operations. © Emerald Group Publishing Limited.

Categorizing 'intention to use' e-government services through mobile phone:the importance of front loading activities

E-government has often been heralded as the new way forwards for emerging countries. While many such countries are already offering e-government services and are gearing up for further growth, little is actually known of the forming stages that are necessary to ensure a greater rate of success and avoid the traditional failure traps linked to new technology and information system adoption and diffusion. We situate our research in the case of mobile phone as a reflection of the current market situation in emerging countries. We contend, in this paper, that more research is needed to understand future intention to use e-government services through mobile phone technology. Front loading activities both from a government and technology perspectives are required to facilitate the decision making process by users.