333 research outputs found
SWEtaxben: A Swedish Tax/Benefit Micro Simulation Model and an Evaluation of a Swedish Tax Reform
The purpose of SWEtaxben is to evaluate the impact of changes in the tax/benefit systems on households as well as the central governmental budget. Relating to the micro simulation literature this model can be labeled a static micro simulation model with behavioral changes. This behavioral change takes two different forms and use two different types of models; first binary models that describe mobility in/out from non-work states such as old age pension, disability, unemployment, long term sickness and second models that describe change in working hours and welfare participation. Thus, apart from the choice to work or not to work, working hours conditional on working as well as welfare participation are treated as endogenous variables. As an application the model is used to evaluate the recent Swedish "make work pay" reform, effective from 2007 and further reinforced in 2008 and 2009. The key characteristic of this reform is an in-work tax credit and decreased state tax rate. Simulations performed by SWEtaxben show increased working hours at both the intensive as well as extensive margin. The tax decrease together with dynamic changes results in a strong increase in household's incomes but also a reduction in income inequality. However, even considering the increase in hours of work, the reform is far from being self-financed.micro simulation, tax-benefit system, in-work tax credit reform
SWEtaxben: a Swedish tax/benefit micro simulation model and an evaluation of a Swedish tax reform
The purpose of SWEtaxben is to evaluate the impact of changes in the tax/benefit systems on households as well as the central governmental budget. Relating to the micro simulation literature this model can be labeled a static micro simulation model with behavioral changes. This behavioral change takes two different forms and use two different types of models; first binary models that describe mobility in/out from non-work states such as old age pension, disability, unemployment, long term sickness and second models that describe change in working hours and welfare participation. Thus, apart from the choice to work or not to work, working hours conditional on working as well as welfare participation are treated as endogenous variables. As an application the model is used to evaluate the recent Swedish make work pay reform, effective from 2007 and further reinforced in 2008 and 2009. The key characteristic of this reform is an in-work tax credit and decreased state tax rate. Simulations performed by SWEtaxben show increased working hours at both the intensive as well as extensive margin. The tax decrease together with dynamic changes results in a strong increase in household's incomes but also a reduction in income inequality. However, even considering the increase in hours of work, the reform is far from being self-financed
Toothed whale auditory brainstem responses measured with a non-invasive, on-animal tag
This work was funded by Grant No. N00014-20-1-2748 from the United States Office of Naval Research (ONR) awarded to M.W. Tag development was supported by ONR Grant Nos. N00014-16-1-2852, N00014-18-1-2062, and N00014-20-1-2709. M.J. was supported by the Aarhus University Research Foundation and the EU H2020 research and innovation program under Marie Skłodowska-Curie Grant No. 754513.Empirical measurements of odontocete hearing are limited to captive individuals, constituting a fraction of species across the suborder. Data from more species could be available if such measurements were collected from unrestrained animals in the wild. This study investigated whether electrophysiological hearing data could be recorded from a trained harbor porpoise (Phocoena phocoena) using a non-invasive, animal-attached tag. The results demonstrate that auditory brainstem responses to external and self-generated stimuli can be measured from a stationary odontocete using an animal-attached recorder. With additional development, tag-based electrophysiological platforms may facilitate the collection of hearing data from freely swimming odontocetes in the wild.Publisher PDFPeer reviewe
Indirect approach to continuous time system identification of food extruder
A three-stage approach to system identification in the
continuous time is presented which is appropriate for
day-to-day application by plant engineers in the process
industry. The three stages are: data acquisition using
relay feedback; non-parametric identification of the
system step response; and parametric model fitting of
the identified step response. The method is evaluated on
a pilot-scale food-cooking extruder
Single-click beam patterns suggest dynamic changes to the field of view of echolocating Atlantic Spotted Dolphins (Stenella frontalis) in the wild
The study was funded by frame grants from the Danish Natural Science Foundation to P.T.M. and M.W., and by the National Oceanographic Partnership Programme via a research agreement between La Laguna University (N.A.d.S.) and the Woods Hole Oceanographic Institution (M.J.). F.H.J. was supported by the Danish Council for Independent Research | Natural Sciences, and is currently funded by a postdoctoral fellowship from the Carlsberg FoundationEcholocating animals exercise an extensive control over the spectral and temporal properties of their biosonar signals to facilitate perception of their actively generated auditory scene when homing in on prey. The intensity and directionality of the biosonar beam defines the field of view of echolocating animals by affecting the acoustic detection range and angular coverage. However, the spatial relationship between an echolocating predator and its prey changes rapidly, resulting in different biosonar requirements throughout prey pursuit and capture. Here, we measured single-click beam patterns using a parametric fit procedure to test whether free-ranging Atlantic spotted dolphins (Stenella frontalis) modify their biosonar beam width. We recorded echolocation clicks using a linear array of receivers and estimated the beam width of individual clicks using a parametric spectral fit, cross-validated with well-established composite beam pattern estimates. The dolphins apparently increased the biosonar beam width, to a large degree without changing the signal frequency, when they approached the recording array. This is comparable to bats that also expand their field of view during prey capture, but achieve this by decreasing biosonar frequency. This behaviour may serve to decrease the risk that rapid escape movements of prey take them outside the biosonar beam of the predator. It is likely that shared sensory requirements have resulted in bats and toothed whales expanding their acoustic field of view at close range to increase the likelihood of successfully acquiring prey using echolocation, representing a case of convergent evolution of echolocation behaviour between these two taxa.PostprintPeer reviewe
Data compression for estimation of the physical parameters of stable and unstable linear systems
A two-stage method for the identification of physical system parameters from experimental data is presented. The first stage compresses the data as an empirical model which encapsulates the data content at frequencies of interest. The second stage then uses data extracted from the empirical model of the first stage within a nonlinear estimation scheme to estimate the unknown physical parameters. Furthermore, the paper proposes use of exponential data weighting in the identification of partially unknown, unstable systems so that they can be treated in the same framework as stable systems. Experimental data are used to demonstrate the efficacy of the proposed approach
Sperm whale codas may encode individuality as well as clan identity
The research was funded by the Danish Research Council; the Carlsberg Foundation; Fundação para a Ciência e a Tecnologia (FCT); Fundo Regional da Ciência, Tecnologia (FRCT) through research projects TRACE-PTDC/MAR/74071/2006 and MAPCET-M2.1.2/F/012/2011 [Fundo Europeu de Desenvolvimento Regional, the Competitiveness Factors Operational (COMPETE), Quadro de Referência Estratégico Nacional (QREN) European Social Fund, and Proconvergencia Açores/European Union Program]; Aarhus University; Woods Hole Oceanographic Institution; University of Southern Denmark and University of La Laguna. We acknowledge funds provided by FCT to MARE – Marine and Environmental Sciences Centre (UID/MAR/04292/2013) and Instituto do Mar at University of the Azores and by the FRCT – Government of the Azores pluriannual funding. C.O. was funded by FCT (SFRH/BD/37668/2007). M.A.S. was supported by an FCT postdoctoral grant (SFRH/BPD/29841/2006) and is currently supported by POPH, QREN European Social Fund and the Portuguese Ministry for Science and Education, through an FCT Investigator grant. M.J. is supported by the Marine Alliance for Science and Technology Scotland (MASTS) and a Marie Curie Career Integration Grant. D.M.W. was funded by a Ph.D. stipend from the Oticon Foundation, Denmark.Sperm whales produce codas for communication that can be grouped into different types according to their temporal patterns. Codas have led researchers to propose that sperm whales belong to distinct cultural clans, but it is presently unclear if they also convey individual information. Coda clicks comprise a series of pulses and the delay between pulses is a function of organ size, and therefore body size, and so is one potential source of individual information. Another potential individual-specific parameter could be the inter-click intervals within codas. To test whether these parameters provide reliable individual cues, stereo-hydrophone acoustic tags (Dtags) were attached to five sperm whales of the Azores, recording a total of 802 codas. A discriminant function analysis was used to distinguish 288 5 Regular codas from four of the sperm whales and 183 3 Regular codas from two sperm whales. The results suggest that codas have consistent individual features in their inter-click intervals and inter-pulse intervals which may contribute to individual identification. Additionally, two whales produced different coda types in distinct foraging dive phases. Codas may therefore be used by sperm whales to convey information of identity as well as activity within a social group to a larger extent than previously assumed.Publisher PDFPeer reviewe
Evaluation of the NASA Arc Jet Capabilities to Support Mission Requirements
NASA accomplishes its strategic goals through human and robotic exploration missions. Many of these missions require launching and landing or returning spacecraft with human or return samples through Earth's and other planetary atmospheres. Spacecraft entering an atmosphere are subjected to extreme aerothermal loads. Protecting against these extreme loads is a critical element of spacecraft design. The safety and success of the planned mission is a prime concern for the Agency, and risk mitigation requires the knowledgeable use of thermal protection systems to successfully withstand the high-energy states imposed on the vehicle. Arc jets provide ground-based testing for development and flight validation of re-entry vehicle thermal protection materials and are a critical capability and core competency of NASA. The Agency's primary hypersonic thermal testing capability resides at the Ames Research Center and the Johnson Space Center and was developed and built in the 1960s and 1970s. This capability was critical to the success of Apollo, Shuttle, Pioneer, Galileo, Mars Pathfinder, and Orion. But the capability and the infrastructure are beyond their design lives. The complexes urgently need strategic attention and investment to meet the future needs of the Agency. The Office of Chief Engineer (OCE) chartered the Arc Jet Evaluation Working Group (AJEWG), a team of experienced individuals from across the Nation, to capture perspectives and requirements from the arc jet user community and from the community that operates and maintains this capability and capacity. This report offers the AJEWG's findings and conclusions that are intended to inform the discussion surrounding potential strategic technical and investment strategies. The AJEWG was directed to employ a 30-year Agency-level view so that near-term issues did not cloud the findings and conclusions and did not dominate or limit any of the strategic options
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