923 research outputs found
Comparing willingness-to-pay and subjective well-being in the context of non-market goods
In order to value non-market goods, economists estimate individualsâ willingness to pay (WTP) for these goods using revealed or stated preference methods. We compare these conventional approaches with subjective well-being (SWB), which is based on individualsâ ratings of their happiness or life satisfaction rather than on their preferences. In the context of a quasi- experiment in urban regeneration, we find that monetary estimates from SWB data are significantly higher than from revealed and stated preference data. Stigma in revealed preferences, mental accounting in stated preferences and unspecified duration in SWB ratings might explain some of the difference between the valuation methods
Do house prices overreact to relevant information? New evidence from the UK housing market
We use recent panel data and various empirical models to investigate the validity of the irrational expectations hypothesis and the feedback theory in the UK housing market. We provide the first empirical evidence to justify the statistically significant and positive feedback causality effect between the changes in bubbles and the contemporaneous changes in house prices. While we have found evidence to support the idea that the irrational expectation hypothesis best fits the UK housing market in the short-run, we failed to find evidence in support of the feedback theory. We observe that an increase in bubbles could cause a subsequent decrease in house prices, ceteris paribus, suggesting that people also learn from their mistakes and attempt to compromise by acting as rationally as possible. Overall, we observe that the causality effects are asymmetrical, being more significant from bubble to house price than they are from house price to bubble
Weak Lensing Peaks in Simulated Light-Cones: Investigating the Coupling between Dark Matter and Dark Energy
In this paper, we study the statistical properties of weak lensing peaks in
light-cones generated from cosmological simulations. In order to assess the
prospects of such observable as a cosmological probe, we consider simulations
that include interacting Dark Energy (hereafter DE) models with coupling term
between DE and Dark Matter. Cosmological models that produce a larger
population of massive clusters have more numerous high signal-to-noise peaks;
among models with comparable numbers of clusters those with more concentrated
haloes produce more peaks. The most extreme model under investigation shows a
difference in peak counts of about with respect to the reference
CDM model. We find that peak statistics can be used to
distinguish a coupling DE model from a reference one with the same power
spectrum normalisation. The differences in the expansion history and the growth
rate of structure formation are reflected in their halo counts, non-linear
scale features and, through them, in the properties of the lensing peaks. For a
source redshift distribution consistent with the expectations of future
space-based wide field surveys, we find that typically seventy percent of the
cluster population contributes to weak-lensing peaks with signal-to-noise
ratios larger than two, and that the fraction of clusters in peaks approaches
one-hundred percent for haloes with redshift z0.5. Our analysis
demonstrates that peak statistics are an important tool for disentangling DE
models by accurately tracing the structure formation processes as a function of
the cosmic time.Comment: accepted in MNRAS, figures improved and text update
Carbon-ammonia pairs for adsorption refrigeration applications : ice making, air conditioning and heat pumping
A thermodynamic cycle model is used to select an optimum adsorbent-refrigerant pair in respect of a chosen figure of merit that could be the cooling production (MJ m(-3)), the heating production (MJ m(-3)) or the coefficient of performance (COP). This model is based mainly on the adsorption equilibrium equations of the adsorbent-refrigerant pair and heat flows. The simulation results of 26 various activated carbon-ammonia pairs for three cycles (single bed, two-bed and infinite number of beds) are presented at typical conditions for ice making, air conditioning and heat pumping applications. The driving temperature varies from 80 degrees C to 200 degrees C. The carbon absorbents investigated are mainly coconut shell and coal based types in multiple forms: monolithic, granular, compacted granular, fibre, compacted fibre, cloth, compacted cloth and powder. Considering a two-bed cycle, the best thermal performances based on power density are obtained with the monolithic carbon KOH-AC, with a driving temperature of 100 degrees C; the cooling production is about 66 MJ m(-3) (COP = 0.45) and 151 MJ m(-3) (COP = 0.61) for ice making and air conditioning respectively; the heating production is about 236 MJ m(-3) (COP = 1.50)
Development of a domestic adsorption gas-fired heat pump
Part of:
Thermally driven heat pumps for heating and cooling. â
Ed.: Annett KĂŒhn â
Berlin: UniversitÀtsverlag der TU Berlin, 2013
ISBN 978-3-7983-2686-6 (print)
ISBN 978-3-7983-2596-8 (online)
urn:nbn:de:kobv:83-opus4-39458
[http://nbn-resolving.de/urn:nbn:de:kobv:83-opus4-39458]A gas-fired heat pump system intended to replace conventional condensing boilers is under development. The machine uses four sorption generators with heat recovery between all beds plus mass recovery and has a nominal heat output of 7 kW. Predicted annual average heating COP (Heat output / gas energy input based on gross calorific value) is 1.35 in a UK application with low temperature radiators. The system is described together with the simulation model, the test facilities and procedures
United States Federal Tax Policy Surrounding The Investment Tax Credit: A Review of Legislative Intent and Empirical Research Findings Over Thirty Years (1962-1991)
Congress enacts tax legislation amidst numerous concerns beyond mere revenue raising. Significant congressional tax policy consideration is conferred upon social objectives, equity concerns, administrative matters, and macroeconomic goals. Within the purview of macro-economic goals can be found federal tax policy relating to investments in fixed assets - which assets are depreciable, the allowable depreciation methods, depreciable lives, and the investment tax credit. Federal tax policy concerning the investment tax credit (ITC) is the topic of this article
Mirroring to Build Trust in Digital Assistants
We describe experiments towards building a conversational digital assistant
that considers the preferred conversational style of the user. In particular,
these experiments are designed to measure whether users prefer and trust an
assistant whose conversational style matches their own. To this end we
conducted a user study where subjects interacted with a digital assistant that
responded in a way that either matched their conversational style, or did not.
Using self-reported personality attributes and subjects' feedback on the
interactions, we built models that can reliably predict a user's preferred
conversational style.Comment: Preprin
National Aeronautics and Space Administration (NASA) Environmental Control and Life Support (ECLS) Integrated Roadmap Development
Although NASA is currently considering a number of future human space exploration mission concepts, detailed mission requirements and vehicle architectures remain mostly undefined, making technology investment strategies difficult to develop and sustain without a top-level roadmap to serve as a guide. This paper documents the process and results of an effort to define a roadmap for Environmental Control and Life Support Systems (ECLSS) capabilities required to enhance the long-term operation of the International Space Station (ISS) as well as enable beyond-Low Earth Orbit (LEO) human exploration missions. Three generic mission types were defined to serve as a basis for developing a prioritized list of needed capabilities and technologies. Those are 1) a short duration micro-gravity mission; 2) a long duration microgravity mission; and 3) a long duration partial gravity (surface) exploration mission. To organize the effort, a functional decomposition of ECLSS was completed starting with the three primary functions: atmosphere, water, and solid waste management. Each was further decomposed into sub-functions to the point that current state-of-the-art (SOA) technologies could be tied to the sub-function. Each technology was then assessed by NASA subject matter experts as to its ability to meet the functional needs of each of the three mission types. When SOA capabilities were deemed to fall short of meeting the needs of one or more mission types, those gaps were prioritized in terms of whether or not the corresponding capabilities enable or enhance each of the mission types. The result was a list of enabling and enhancing capability needs that can be used to guide future ECLSS development, as well as a list of existing hardware that is ready to go for exploration-class missions. A strategy to fulfill those needs over time was then developed in the form of a roadmap. Through execution of this roadmap, the hardware and technologies intended to meet exploration needs will, in many cases, directly benefit the ISS operational capability, benefit the Multi-Purpose Crew Vehicle (MPCV), and guide long-term technology investments for longer duration missions
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