7,989 research outputs found
Agent-based Housing Market Microsimulation for Integrated Land Use, Transportation, Environment Model System
The Housing Market Evolutionary System (HoMES) is the updated housing market module for the Integrated Land Use, Transportation, Environment (ILUTE) model system. HoMES is a disaggregate, agent-based microsimulation of the owner-occupied housing market, with models for households’ residential mobility decisions, location choices and valuations, the endogenous supply of housing by type and location, and the endogenous determination of sale prices and rents. The new model offers significant improvements over previous attempts by including a reformulated market clearing mechanism, market dependency on macro-economic conditions, and improved computational performance. A 100% synthesized population is validated against historical data for the Greater Toronto-Hamilton Area
limit solutions for control systems
For a control Cauchy problem on an interval , we
propose a notion of limit solution verifying the following properties: i)
is defined for (impulsive) inputs and for standard,
bounded measurable, controls ; ii) in the commutative case (i.e. when
for all ),
coincides with the solution one can obtain via the change of coordinates that
makes the simultaneously constant; iii) subsumes former concepts
of solution valid for the generic, noncommutative case.
In particular, when has bounded variation, we investigate the relation
between limit solutions and (single-valued) graph completion solutions.
Furthermore, we prove consistency with the classical Carath\'eodory solution
when and are absolutely continuous.
Even though some specific problems are better addressed by means of special
representations of the solutions, we believe that various theoretical issues
call for a unified notion of trajectory. For instance, this is the case of
optimal control problems, possibly with state and endpoint constraints, for
which no extra assumptions (like e.g. coercivity, bounded variation,
commutativity) are made in advance
Does lowering the screening age for cervical cancer in The Netherlands make sense?\ud
Recommendations for the age to initiate cervical cancer screening should be directed towards maximum detection of early cervical cancer. However, the screening programme should do more good than harm. The aim of this analysis was to determine whether the target age for cervical cancer screening should be lowered in view of apparent increases in new cases of invasive cancer below age 30 and in age group 30–44 years in The Netherlands. Therefore, all cervical cancer cases diagnosed between January 1, 1989 and December 31, 2003 were selected from the nationwide population-based Netherlands Cancer Registry. For age group 25–39 years, incidence data were also available for 2004 and 2005. To describe trends, the estimated annual percentage of change and joinpoint analysis were used. Between ages 25 and 28 years, the absolute number of new cases of cervical cancer annually has varied between 0 and 9 per age. Significantly decreasing trends in incidence were observed for age groups 35–39 and 45–49 (p < 0.0001 and p = 0.01, respectively). The annual number of deaths fluctuated with a decreasing trend for age groups 30–34 and 35–39 years (p = 0.01 and p = 0.03, respectively). Because the incidence and mortality rates for cervical cancer among women younger than 30 are low and not increasing, lowering the age for cervical cancer screening is not useful at this time. Although the number of years of life gained is high for every case of cervical cancer prevented, the disadvantages of lowering the screening age would be very large and even become disproportionate compared to the potential advantage
The Key Role of Heavy Precipitation Events in Climate Model Disagreements of Future Annual Precipitation Changes in California
Climate model simulations disagree on whether future precipitation will increase or decrease over California, which has impeded efforts to anticipate and adapt to human-induced climate change. This disagreement is explored in terms of daily precipitation frequency and intensity. It is found that divergent model projections of changes in the incidence of rare heavy (\u3e60 mm day−1) daily precipitation events explain much of the model disagreement on annual time scales, yet represent only 0.3% of precipitating days and 9% of annual precipitation volume. Of the 25 downscaled model projections examined here, 21 agree that precipitation frequency will decrease by the 2060s, with a mean reduction of 6–14 days yr−1. This reduces California\u27s mean annual precipitation by about 5.7%. Partly offsetting this, 16 of the 25 projections agree that daily precipitation intensity will increase, which accounts for a model average 5.3% increase in annual precipitation. Between these conflicting tendencies, 12 projections show drier annual conditions by the 2060s and 13 show wetter. These results are obtained from 16 global general circulation models downscaled with different combinations of dynamical methods [Weather Research and Forecasting (WRF), Regional Spectral Model (RSM), and version 3 of the Regional Climate Model (RegCM3)] and statistical methods [bias correction with spatial disaggregation (BCSD) and bias correction with constructed analogs (BCCA)], although not all downscaling methods were applied to each global model. Model disagreements in the projected change in occurrence of the heaviest precipitation days (\u3e60 mm day−1) account for the majority of disagreement in the projected change in annual precipitation, and occur preferentially over the Sierra Nevada and Northern California. When such events are excluded, nearly twice as many projections show drier future conditions
The knowledge that critical care nurses have of evidence-based practice in their practice
The purpose of this study was to explore and describe the knowledge that a cohort of
40 intensive care unit nurses had of evidence-based practice. It was assumed that they
lacked the knowledge to locate, evaluate understand and apply research findings.
Quantitative, non-experimental descriptive research was conducted to explore their
knowledge and to formulate recommendations for promoting it. Data collection involved
administering a structured questionnaire administered to the cohort in an intensive care
unit. The findings revealed that, although they were familiar with the basic concept of
evidence-based practice, they were reluctant and lacked the skills to adopt it in their
practice. It is recommended that they be trained and empowered to develop research
expertise from within their own ranks. Finally it is recommended that nursing
management should play a more proactive role in identifying cost-effective strategies in
overcoming barriers to finding, promoting and integrating evidence-based practiceHealth StudiesM.A. (Health Studies
Probabilistic estimates of future changes in California temperature and precipitation usingstatistical and dynamical downscaling
Sixteen global general circulation models were used to develop probabilistic projections of temperature (T) and precipitation (P) changes over California by the 2060s. The global models were downscaled with two statistical techniques and three nested dynamical regional climate models, although not all global models were downscaled with all techniques. Both monthly and daily timescale changes in T and P are addressed, the latter being important for a range of applications in energy use, water management, and agriculture. The T changes tend to agree more across downscaling techniques than the P changes. Year-to-year natural internal climate variability is roughly of similar magnitude to the projected T changes. In the monthly average, July temperatures shift enough that that the hottest July found in any simulation over the historical period becomes a modestly cool July in the future period. Januarys as cold as any found in the historical period are still found in the 2060s, but the median and maximum monthly average temperatures increase notably. Annual and seasonal P changes are small compared to interannual or intermodel variability. However, the annual change is composed of seasonally varying changes that are themselves much larger, but tend to cancel in the annual mean. Winters show modestly wetter conditions in the North of the state, while spring and autumn show less precipitation. The dynamical downscaling techniques project increasing precipitation in the Southeastern part of the state, which is influenced by the North American monsoon, a feature that is not captured by the statistical downscaling
First-Principles Semiclassical Initial Value Representation Molecular Dynamics
A method for carrying out semiclassical initial value representation
calculations using first-principles molecular dynamics (FP-SC-IVR) is
presented. This method can extract the full vibrational power spectrum of
carbon dioxide from a single trajectory providing numerical results that agree
with experiment even for Fermi resonant states. The computational demands of
the method are comparable to those of classical single-trajectory calculations,
while describing uniquely quantum features such as the zero-point energy and
Fermi resonances. By propagating the nuclear degrees of freedom using
first-principles Born-Oppenheimer molecular dynamics, the stability of the
method presented is improved considerably when compared to dynamics carried out
using fitted potential energy surfaces and numerical derivatives.Comment: 5 pages, 2 figures, made stylistic and clarity change
Ethical issues for magistrates: manual for trainers
The manual contains readings, worksheets and teaching materials. There are also notes for trainers. This training manual was a landmark in an ongoing programme to develop an understanding of judicial ethics and to help magistrates deal more easily with the many, complicated ethical issues that arise in their day-to-day work. Many magistrates had raised concerns about their limited understanding ofjudicial ethics, the absence of any real discussion of ethical issues amongst magistrates, and the need for thorough and ongoing training in ethics.
The first stage of the programme involved comparative and local research. A series of discussions with magistrates and workshops at which newly developed training exercises were tried out comprised the second stage of the programme. The production of this manual marked the conclusion of the third stage.
The manual is divided into six training modules, each of which includes a discussion of the subject at hand and a number of exercises which can be used in training. Most of the examples that are included were provided by the magistrates with whom we discussed the manual or who participated in the workshops
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