2,342 research outputs found
Housing outcomes: an assessment of long-term trends
This paper was presented at the conference "Unequal incomes, unequal outcomes? Economic inequality and measures of well-being" as part of session 2, " Affordability of housing for young and poor families." The conference was held at the Federal Reserve Bank of New York on May 7, 1999. The authors examine trends in housing outcomes by income group. Orr and Peach indicate that there has been a substantial improvement in the physical adequacy of the housing stock over the past few decades, particularly for households in the lowest income quintile. Neighborhood quality for all income groups has also improved, although sharp differences in quality continue to exist across the groups. In one important respect, however, lower income households are worse off than before - housing costs now absorb a larger share of their income.Housing ; Housing - Finance
The Docks After Devlin, by Michael Mellish, London, Heinemann Educational Books, 1972, 146 pp.
Competition and Collective Bargaining in the Needle Trades, 1910-1967, by Jesse Thomas Carpenter, Ithaca, The New York State School of Industrial and Labor Relations, Cornell University, 1972, 910 pp.
The Canadair-I.A.M. Productivity Improvement Plan
This paper presents the experience of Canadair-I.A.M. Productivity Improvement Plan
The 'Sphere': A Dedicated Bifurcation Aneurysm Flow-Diverter Device.
We present flow-based results from the early stage design cycle, based on computational modeling, of a prototype flow-diverter device, known as the 'Sphere', intended to treat bifurcation aneurysms of the cerebral vasculature. The device is available in a range of diameters and geometries and is constructed from a single loop of NITINOL(®) wire. The 'Sphere' reduces aneurysm inflow by means of a high-density, patterned, elliptical surface that partially occludes the aneurysm neck. The device is secured in the healthy parent vessel by two armatures in the shape of open loops, resulting in negligible disruption of parent or daughter vessel flow. The device is virtually deployed in six anatomically accurate bifurcation aneurysms: three located at the Basilar tip and three located at the terminus bifurcation of the Internal Carotid artery (at the meeting of the middle cerebral and anterior cerebral arteries). Both steady state and transient flow simulations reveal that the device presents with a range of aneurysm inflow reductions, with mean flow reductions falling in the range of 30.6-71.8% across the different geometries. A significant difference is noted between steady state and transient simulations in one geometry, where a zone of flow recirculation is not captured in the steady state simulation. Across all six aneurysms, the device reduces the WSS magnitude within the aneurysm sac, resulting in a hemodynamic environment closer to that of a healthy vessel. We conclude from extensive CFD analysis that the 'Sphere' device offers very significant levels of flow reduction in a number of anatomically accurate aneurysm sizes and locations, with many advantages compared to current clinical cylindrical flow-diverter designs. Analysis of the device's mechanical properties and deployability will follow in future publications
Union and Management Decision-Making in the Grievance Process
La prise de décision en matière de règlement des griefs suscite toute une série d'interactions entre le syndicat et la direction. Le présent article est fondé sur une étude qui s'est faite dans cinq entreprises de sidérurgie aux États-Unis au cours des années 1967 et 1968. Le travail a consisté dans l'analyse des dossiers, dans des entrevues et des observations diverses. Évidemment, les constatations ne portent que sur une seule industrie, celle de l'acier mais, à quelques nuances près, elles sont susceptibles de valoir d'une façon générale, du moins dans l'industrie manufacturière.Les cas, qui ont été analysés, peuvent se diviser en cinq groupes distincts : la violation de la convention collective par l'employeur, le désaccord sur des faits, l'interprétation de la convention collective, la façon dont la convention est appliquée, les divergences d'opinion au sujet des méthodes d'action.D'une part, on s'est intéressé d'abord au comportement du syndicat qui peut différer selon sa conception de l'action syndicale, selon son état en tant qu'institution de nature politique. Certains syndiqués s'attaquent automatiquement aux décisions patronales et présentent des griefs formels à chaque fois que l'occasion s'en présente. D'autres syndicats s'attaquent principalement aux nouvelles classifications d'emploi et les griefs de ce genre se règlent généralement en présence du représentant international ou sont soumis à l'arbitrage. D'autres, par exemple, combattent vigoureusement la sous-traitance. Enfin, des griefs formels sont soumis et portés à l'arbitrage chaque fois qu'un salarié ou un groupe de salariés a quelque raison d'espérer de l'arbitrage un avantage matériel quelconque.La situation politique au sein du syndicat exerce aussi une influence certaine sur la façon de traiter les griefs. Le nombre des griefs a tendance à augmenter lorsqu'il y a lutte entre différents clans à l'intérieur du syndicat et l'attitude à l'endroit des réclamations revêt alors une saveur électorale. On observe aussi un phénomène identique lorsque des groupes de pression se forment pour combattre une décision patronale dans un département.Toutefois, du côté syndical, le principal facteur qui influe su? le traitement des griefs est sans conteste l'attitude des dirigeants. On peut, à ce propos, classer les dirigeants syndicaux en cinq catégories : il y a les inactifs, les chefs soucieux de régler les problèmes, les avocats et, finalement, les radicaux et les politiciens.Selon ces différents types de dirigeants syndicaux, on procédera différemment dans le traitement des griefs. L'inactif ne bouge pas : le véritable négociateur a tendance à éviter la présentation de griefs écrits et à discute? au mérite chaque cas soumis ; l'avocat est enclin à défendre la cause jusqu'au bout, qu'elle soit bonne ou non ; quant aux politiciens, ils amassent du capital et, avec les radicaux, ils contestent systématiquement les décisions patronales.La nature du travail, l'organisation de l'entreprise et le milieu ambiant jouent aussi un rôle sur le nombre des griefs et la façon de les traiter. Ainsi, dans une localité dont la population est peu nombreuse sera-t-on plus enclin à discuter les griefs d'une façon informelle. Enfin, il faut noter que la façon dont procède la direction dans la prise de décision et l'organisation même du service de relations du travail comptent pour beaucoup dans la façon dont les syndicats agissent en matière de traitement des réclamations. Il arrive que le service des relations du travail ne bouge pas tant qu'il n'est pas en présence d'un grief présenté par écrit en bonne et due forme.Du côté patronal, l'attitude des dirigeants peut se comparer dans une certaine mesure à celle des chefs syndicaux. L'enquête a permis de déceler qu'il y a des employeurs inactifs qui cherchent à éluder les problèmes ou se contentent de référer les cas soumis au service des relations du travail, les dirigeants soucieux de régler les problèmes d'une façon informelle tout comme leurs collègues syndicaux et, enfin, les employeurs autocratiques, qui, au nom du principe de l'autorité, ont pour politique de défendre jusqu'au bout ce qu'ils considèrent être de leurs prérogatives qu'elles soient justes ou non, et qui sont fermés à toute forme; de compromis. Ces attitudes de base se reflètent naturellement dans la façon de traiter les griefs aux différentes étapes de la procédure.Dans l'ensemble, on peut dire que, en règle générale, l'attitude des employeurs dépend beaucoup de celle des chefs syndicaux, et il y a là une interaction certaine. Il faut aussi noter que, aux étapes préliminaires de la discussion, les employeurs sont sensibles à ce que serait la décision d'un arbitre ou d'un tribunal d'arbitrage. Ils tiennent généralement compte du coût financier du litige et aussi des avantages que peuvent apporter à longue échéance des compromis acceptables.En bref, le syndicat, devant un grief, doit décider s'il doit le défendre et comment il lui faut le défendre : d'autre part, sujet aux stipulations du contrai:, l'employeur se place dans une situation à peu près identique de défense.Based on a study of five U.S. Steel Company, this paper explains union-management interactions in the grievance process
Scale-dependent measure of network centrality from diffusion dynamics
Classic measures of graph centrality capture distinct aspects of node importance, from the local (e.g., degree) to the global (e.g., closeness). Here we exploit the connection between diffusion and geometry to introduce a multiscale centrality measure. A node is defined to be central if it breaks the metricity of the diffusion as a consequence of the effective boundaries and inhomogeneities in the graph. Our measure is naturally multiscale, as it is computed relative to graph neighbourhoods within the varying time horizon of the diffusion. We find that the centrality of nodes can differ widely at different scales. In particular, our measure correlates with degree (i.e., hubs) at small scales and with closeness (i.e., bridges) at large scales, and also reveals the existence of multi-centric structures in complex networks. By examining centrality across scales, our measure thus provides an evaluation of node importance relative to local and global processes on the network
Characterising groundwater-dominated lowland catchments : the UK Lowland Catchment Research Programme (LOCAR)
This paper reports on a major UK initiative to address deficiencies in understanding the hydro-ecological response of groundwater-dominated lowland catchments. The scope and objectives of this national programme are introduced and focus on one of three sets of research basins – the Pang/Lambourn Chalk catchments, tributaries of the river Thames in southern England. The motivation for the research is the need to support integrated management of river systems that have high ecological value and are subject to pressures that include groundwater abstraction for water supply, diffuse pollution, and land use and climate change. An overview of the research programme is provided together with highlights of some current research findings concerning the hydrological functioning of these catchments. Despite the importance of the Chalk as a major UK aquifer, knowledge of the subsurface movement of water and solutes is poor. Solute transport in the dual porosity unsaturated zone depends on fracture/matrix interactions that are difficult to observe; current experimental and modelling research supports the predominance of matrix flow and suggests that slow migration of a time-history of decades of nutrient loading is occurring. Groundwater flows are complex; catchments vary seasonally and are ill-defined and karst features are locally important. Groundwater flow pathways are being investigated using natural and artificial geochemical tracers based on experimental borehole arrays; stream-aquifer interaction research is using a combination of geophysics, borehole array geochemistry and longitudinal profiles of stream flow and solutes. A complex picture of localised subsurface inflows, linked to geological controls and karst features, and significant longitudinal groundwater flow below the river channel is emerging. Management implications are discussed. Strategies to control surface application of nutrients are expected to have little effect on groundwater quality for several decades, and new modelling tools for decision support have been developed to represent these effects. Conventional modelling approaches are limited by the complexities of the subsurface system; catchment areas are difficult to define, hence tracking pollutant pathways to stream receptors is also problematic. Conventional distributed groundwater models have difficulty in capturing key aspects of the groundwater system. This raises important questions concerning the confidence that can be placed in models as routinely used for decision support and the level of knowledge required for catchmen
Relative, local and global dimension in complex networks
Dimension is a fundamental property of objects and the space in which they are embedded. Yet ideal notions of dimension, as in Euclidean spaces, do not always translate to physical spaces, which can be constrained by boundaries and distorted by inhomogeneities, or to intrinsically discrete systems such as networks. To take into account locality, finiteness and discreteness, dynamical processes can be used to probe the space geometry and define its dimension. Here we show that each point in space can be assigned a relative dimension with respect to the source of a diffusive process, a concept that provides a scale-dependent definition for local and global dimension also applicable to networks. To showcase its application to physical systems, we demonstrate that the local dimension of structural protein graphs correlates with structural flexibility, and the relative dimension with respect to the active site uncovers regions involved in allosteric communication. In simple models of epidemics on networks, the relative dimension is predictive of the spreading capability of nodes, and identifies scales at which the graph structure is predictive of infectivity. We further apply our dimension measures to neuronal networks, economic trade, social networks, ocean flows, and to the comparison of random graphs
An FFAG Transport Line for the PAMELA Project
The PAMELA project to design an accelerator for
hadron therapy using non-scaling Fixed Field Alternating
Gradient (NS-FFAG) magnets requires a transport line
and gantry to take the beam to the patient. The NS-FFAG
principle offers the possibility of a gantry much smaller,
lighter and cheaper than conventional designs, with the
added ability to accept a wide range of fast changing
energies. This paper will build on previous work to
investigate a transport line which could be used for the
PAMELA project. The design is presented along with a
study and optimisation of its acceptance
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