581 research outputs found

    The brezis-ekeland-nayroles minimization principle with mixed finite element method for elastoplastic dynamic problems

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    We propose a modification of the Hamiltonian formalism which can be used for dissipative systems, the Brezis-Ekeland-Nayroles principle. The formalism is specialized to the standard plasticity in small strains and dynamics. We apply it to solve the classical problem of a thin tube in plane strain subjected to an internal pressure. The continuum is discretized with mixed finite elements

    Royale with Cheese: Globalization, Tourism, and the Variety of Goods *

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    Abstract The key result of the so-called "New Trade Theory" is that countries gain from falling trade costs by an increase in the number of varieties available to consumers. Though the number of varieties in a given country rises, many models predict that global variety decreases as imported varieties drive out local varieties. This is potentially worrisome when consumers care about non-exported foreign varieties either due to tourism (especially when foreign varieties are highly desired) or through an existence value (a common tool in environmental economics where simply knowing that a species exists provides utility). Since lowering trade costs induces additional varieties to export and drives out some non-exported varieties, these modifications result in welfare losses not accounted for in the existing literature. Nevertheless, it is only through the existence value that welfare falls as a result of declining trade barriers

    Evaluating Elevated Convection with the Downdraft Convective Inhibition

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    A method for evaluating the penetration of a stable layer by an elevated convective downdraft is discussed. Some controversy exists on the community’s ability to define truly elevated convection from surface-based convection. By comparing the downdraft convective inhibition (DCIN) to the downdraft convective available potential energy (DCAPE), we determine that downdraft penetration potential is progressively enabled as the DCIN is progressively smaller than the DCAPE; inversely as DCIN increases over DCAPE, so does the likelihood of purely elevated convection. Serial vertical soundings and accompanying analyses are provided to support this finding

    4P based forensics investigation framework for smart connected toys

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    © 2020 ACM. Smart Connected Toys (SCTs) have the potential to collect terabytes of sensitive personal, contextual, and usage information which may be a subject of cybercrime or used as a conduit for cybercrime resulting in a digital forensic investigation which requires the examination of the digital artifact stored, processed or transmitted by the SCT. SCT forensics is challenging in most cases due to non-availability of specialized forensics tools and standardized evidence acquisition interface port. We explore the various privacy and security challenges plaguing the SCT industry and the possible safety risk SCT poses to children as a result of a lack of serious consideration technical controls surrounding the collection, processing, and storage of children\u27s information and possible exposure to crime which will require digital forensic investigation. As a result of this gap in research and industry, we investigate current digital forensic solutions for SCTs and present an abstract forensics investigation framework with the focus on using non-conventional means which allow Investigators to successfully Plan, Preserve Process and Present (4P) as a systematic means to conduct digital forensic analysis on an SCT in a situation where SCT is complicit in a criminal investigation or a subject of crime

    Private finance for the delivery of school projects in England

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    This paper analyses the use of the private finance initiative (PFI) approach to deliver school projects in England. The findings are based on case-study research in the Building Schools for the Future scheme (BSF), the largest single capital investment in SO years to rebuild and renew all of England's secondary schools. Up to half of the school infrastructure is to be procured by PFI contracts. A major concern has been the high cost associated with PFI procurement and any subsequent changes to scope. Furthermore, in some cases PFI-funded schools have been closed soon after completion; at great cost to the public sector. The aim of this research was therefore to understand the underlying reasons for these problems. The main conclusion is that the difficulties in BSF arise from not sorting out strategic issues and instituting appropriate organisational frameworks before engaging the private sector. The result of this is a lack of clarity about the long-term needs and end user aspirations. A brief outline of current programme management methods is given and it is suggested that this might be integral to the successful delivery of schools using private finance. A clear strategic vision that cascades into projects via programmes will ensure that the school infrastructure is appropriate for the anticipated strategic benefits and is aligned to the overall service delivery ambitions

    Occupational safety and regulatory compliance in US commercial fishing

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    Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in Archives of Environmental & Occupational Health 66 (2011): 209-216, doi:10.1080/19338244.2011.564237.This study explored occupational safety practices and regulatory compliance in a representative sample of Maine commercial fishing vessels. Data were collected on demographic characteristics, safety equipment and training, and regulatory compliance during at sea boardings of working commercial fishing vessels (n=259). Trends in safety and compliance were explored using standard comparison tests and principal component analysis. More than 40% of vessels were not in compliance with applicable safety regulations. That rate was lower for fishermen subjected to more stringent and costly safety requirements. The vast majority of fishermen were not safety trained, and many were not familiar with the proper use and maintenance of life-saving equipment. There is a clear need for better safety training in this industry. Educational efforts should be targeted at the local level at minimal cost to fishermen to encourage participation.This study was supported by funding from Maine Sea Grant and the National Oceanic and Atmospheric Administration (R/08-03 NA060AR4170108)

    Aquatic food security:insights into challenges and solutions from an analysis of interactions between fisheries, aquaculture, food safety, human health, fish and human welfare, economy and environment

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    Fisheries and aquaculture production, imports, exports and equitability of distribution determine the supply of aquatic food to people. Aquatic food security is achieved when a food supply is sufficient, safe, sustainable, shockproof and sound: sufficient, to meet needs and preferences of people; safe, to provide nutritional benefit while posing minimal health risks; sustainable, to provide food now and for future generations; shock-proof, to provide resilience to shocks in production systems and supply chains; and sound, to meet legal and ethical standards for welfare of animals, people and environment. Here, we present an integrated assessment of these elements of the aquatic food system in the United Kingdom, a system linked to dynamic global networks of producers, processors and markets. Our assessment addresses sufficiency of supply from aquaculture, fisheries and trade; safety of supply given biological, chemical and radiation hazards; social, economic and environmental sustainability of production systems and supply chains; system resilience to social, economic and environmental shocks; welfare of fish, people and environment; and the authenticity of food. Conventionally, these aspects of the food system are not assessed collectively, so information supporting our assessment is widely dispersed. Our assessment reveals trade-offs and challenges in the food system that are easily overlooked in sectoral analyses of fisheries, aquaculture, health, medicine, human and fish welfare, safety and environment. We highlight potential benefits of an integrated, systematic and ongoing process to assess security of the aquatic food system and to predict impacts of social, economic and environmental change on food supply and demand

    Commute replacement and commute displacement the rise of part-day home working

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    Working by telecommunication has been the subject of research attention in transportation studies for many years. Particular consideration has been given to occasional working from home (home working) by (full-time, paid) employees who represent a tangible removal of commute trips on days that people work from home. However, little recognition or attention has been given to the fact that home working not only may be undertaken for part of a week but also may be undertaken for parts of given days. This paper focuses particularly on part-day home working. It defines and uses the term "varied spatiotemporal (VST) working" to describe working days in which at least 30 min of continuous working takes place at home accompanied by work taking place at the workplace. Notably, such home working does not remove the commute trips but can temporally displace one or both of them. The research reported in this paper builds on preceding survey work that had established that the number of people who practice VST working and the number of VST days worked appear to be about double those for full-day home working (which has typically been the focus of research attention). The results presented in this paper are based on 25 in-depth interviews with individuals who practice VST working. The aim of the research was to examine more closely and to understand the nature of VST working and the motivations and constraints for its practice and to consider its potential contribution as a transportation demand management measure
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