Some Aspects of Modality in Analytical Mechanics

This paper discusses some of the modal involvements of analytical mechanics. I first review the elementary aspects of the Lagrangian, Hamiltonian and Hamilton-Jacobi approaches. I then discuss two modal involvements; both are related to David Lewis' work on modality, especially on counterfactuals. The first is the way Hamilton-Jacobi theory uses ensembles, i.e. sets of possible initial conditions. The structure of this set of ensembles remains to be explored by philosophers. The second is the way the Lagrangian and Hamiltonian approaches' variational principles state the law of motion by mentioning contralegal dynamical evolutions. This threatens to contravene the principle that any actual truth, in particular an actual law, is made true by actual facts. Though this threat can be avoided, at least for simple mechanical systems, it repays scrutiny; not least because it leads to some open questions.Comment: 36 pages, no figures. Delivered at a Philosophy of Science Association Symposium in memory of the distinguished philosopher David Lewis, Milwaukee, November 2002. This version includes significant additions to Section 5.1. This version is forthcoming in `Formal Teleology and Causality', ed. M. Stoeltzner, P. Weingartner, Paderborn, Germany: Mentis. A precis of the first half of the paper is forthcoming in the journal Philosophy of Scienc

Energy Access and Electricity Planning

As developing countries look for ways to achieve sustainable energy services, which is essential to lift people out of poverty, the big challenge centers around providing access for all while avoiding past pitfalls without creating new ones. The reality is that this can only occur if there is a fundamental transformation of energy systems along the entire set of resource to energy service chains - and that will necessitate greater energy efficiency and a bigger role for renewables in the global energy mix energy. Competitive and private sector dominated energy markets rely on clear and consistent government energy-environment policies to align their investment decisions with sustainable development objectives. This paper tries to shed light on how developing countries can carry out energy planning by reviewing the available methodologies and tools, including their potential to integrate rural energy access and encourage the uptake of renewable energy technologies. It also probes how investment needs and cost-effectiveness are reflected in different analytic and planning tools - with a case study on Ethiopia. And it examines the interaction of energy planning and scenario development and how these are applied to informed policy making. The findings suggest that energy planning is essential and feasible. However, support is required to improve data collection and access, develop open accessible modelling tools, and build sustainable national capacity to undertake plannin

Association between cognitive performance and cortical glucose metabolism in patients with mild Alzheimer's disease

Background: Neuronal and synaptic function in Alzheimer's disease (AD) is measured in vivo by glucose metabolism using positron emission tomography (PET). Objective: We hypothesized that neuronal activation as measured by PET is a more sensitive index of neuronal dysfunction than activity during rest. We investigated if the correlations between dementia severity as measured with the Mini Mental State Examination (MMSE) and glucose metabolism are an artifact of brain atrophy. Method: Glucose metabolism was measured using {[}F-18]fluorodeoxyglucose PET during rest and activation due to audiovisual stimulation in 13 mild to moderate AD patients (MMSE score >= 17). PET data were corrected for brain atrophy. Results: In the rest condition, glucose metabolism was correlated with the MMSE score primarily within the posterior cingulate and parietal lobes. For the activation condition, additional correlations were within the primary and association audiovisual areas. Most local maxima remained significant after correcting for brain atrophy. Conclusion: PET activity measured during audiovisual stimulation was more sensitive to functional alterations in glucose metabolism in AD patients compared to the resting PET. The association between glucose metabolism and MMSE score was not dependent on brain atrophy. Copyright (C) 2005 S. Karger AG, Basel

Turning to Peers: Integrating Understanding of the Self, the Condition, and Others’ Experiences in Making Sense of Complex Chronic Conditions

People are increasingly involved in the self-management of their own health, including chronic conditions. With technology advances, the choice of self-management practices, tools, and technologies has never been greater. The studies reported here investigated the information seeking practices of two different chronic health populations in their quest to manage their health conditions. Migraine and diabetes patients and clinicians in the UK and the US were interviewed about their information needs and practices, and representative online communities were explored to inform a qualitative study. We found that people with either chronic condition require personally relevant information and use a broad and varied set of practices and tools to make sense of their specific symptoms, triggers, and treatments. Participants sought out different types of information from varied sources about themselves, their medical condition, and their peers’ experiences of the same chronic condition. People with diabetes and migraine expended great effort to validate their personal experiences of their condition and determine whether these experiences were ‘normal’. Based on these findings, we discuss the need for future personal health technologies that support people in engaging in meaningful and personalised data collection, information seeking, and information sharing with peers in flexible ways that enable them to better understand their own condition

Desalination using renewable energy sources on the arid islands of South Aegean Sea

Water and energy supply are strongly interrelated and their efficient management is crucial for a sustainable future. Water and energy systems on several Greek islands face a number of pressing issues. Water supply is problematic as regards both to the water quality and quantity. There is significant lack of water on several islands and this is mainly dealt with tanker vessels which transport vast amounts of water from the mainland. At the same time island energy systems are congested and rely predominanty on fossil fuels, despite the abundant renewable energy potential. These issues may be addressed by combining desalination and renewable energy technologies. It is essential to analyse the feasibility of this possibility. This study focuses on developing a tool capable of designing and optimally sizing desalination and renewable energy units. Several parameters regarding an island's water demandand the desalination's energy requirements are taken into account as well as input data which concern technological performance, resource availability and economic data. The tool is applied on three islands in the South Aegean Sea, Patmos (large), Lipsoi (medium) ad Thirasia (small). Results of the modelling exercise show that the water selling price ranges from 1.45 euro/m^3 for the large island, while the corresponding value is about 2.6 euro/m^3 for the small island, figures significantly lower than the current water cost (7-9 euro/m^3)

Designing for the experiential body

The goal of this panel is to reflect on the past and discuss the present and future of designing for an experiencing body in HCI. The motivation is to discuss the full range of rich body/movement-based experiences and how the CHI community can embrace and extend these perspectives on designing for the body. The panelists and audience will be asked to share their perspectives on what has most influenced thought in designing for the body, how new sensing technologies are crafting the HCI perspective, and where they see this line of research and design heading in the next ten years

Dairy Farm Business Summary: Central Valleys Region 1997

E.B. 98-12Dairy farm managers throughout New York State have been participating in Cornell Cooperative Extension's farm business summary and analysis program since the early 1950's. Managers of each participating farm business receive a comprehensive summary and analysis of their farm business. The information in this report represents averages of the data submitted from dairy farms in the Central Valleys Region for 1997

HCI and Health: Learning from Interdisciplinary Interactions

HCI has multidisciplinary roots and has drawn from and contributed to different disciplines, including computer science, psychology, sociology, and medicine. There is a natural overlap between health and HCI researchers, given their joint focus on utilising technologies to better support people’s health and wellbeing. However, the best digital health interventions are not simply the result of the ‘application’ of HCI to the domain of healthcare, but emerge when researchers from both camps seek to overcome differences in disciplinary practices, traditions, and values in order to collaborate more effectively and productively. We propose a special interest group (SIG) to include interdisciplinary researchers (i.e., participants active in both communities) as well as researchers from either discipline, but with interests in the other field

A Metaheuristic for Autonomous and Self-Organizing Consensus Formation Inspired by Honey Bee Nest Site Selection Behavior

This research presents a self-organizing system for engineering consensus among cooperating, distributed processes and studying consensus negotiation in natural systems that use the quorum sensing mechanism. The presented method combines metaheuristic techniques and a negotiation protocol based on honey bee nest site selection behavior in order to optimize the collective social utility of a group decision. Unlike existing negotiation and voting protocols, the proposed metaheuristic accommodates negotiation of consensus from among two or more decision values. It is decentralized, self-organizing, and does not require a fully-connected network in which each process can communicate directly with each other. Benefits of these attributes are that there is no central point of failure, and processes can make informed decisions using only information acquired from immediate neighbors, rather than requiring the consolidation and evaluation of global preferences. The proposed metaheuristic is modeled as an agent-based system using the Repast modeling and simulation framework, and this model is used to conduct simulation experiments in accordance with the Design of Experiments methodology to analyze the Honey Bee Consensus metaheuristic and its performance on multiple social network models. As the Honey Bee Consensus metaheuristic is an extension and new application of a recently-proposed agent-oriented Quorum Sensing pattern, the presented understanding of its parameter and topology influence is of value in steering the behavior of self-organizing systems based on the Quorum Sensing pattern language. Additionally, understanding how network topology influences consensus formation has applications spanning decision theory, social choice theory, network science, and control theory. Significant outcomes of this research include a description of the proposed metaheuristic and the identification of a quorum size to population ratio that provides optimal speed-accuracy tradeoff for a range of population sizes and social network models

A Combined Equaliser and Decoder for Maximum Likelihood Decoding of Convolutional Codes in the presence of ISI. Incorporation into GSM 3GPP Standard

The dissertation describes a new approach in combining the equalising and decoding operations in wireless telecommunications, namely MS decoder. It provides performance results (SNR) and carries out simulations based on GSM 3GPP standard