11,004 research outputs found
The Effects of Critical Habitat Designation on Housing Supply: An Analysis of California Housing Construction Activity
Under the Endangered Species Act, the U.S. Fish and Wildlife Service is required to designate critical habitat for listed species. Designation could result in modification to or delay of residential development projects within habitat boundaries, generating concern over potential housing market impacts. This paper draws upon a large dataset of municipal-level (FIPS) building permit issuances and critical habitat designations in California over a 13-year period to identify changes in the spatial and temporal pattern of development activity associated with critical habitat designation. We find that the proposal of critical habitat results in a 20.5% decrease in the annual supply of housing permits in the short-run and a 32.6% decrease in the long-run. Further, the percent of the FIPS area that is designated as critical habitat significantly affects the number of permits issued. We also find that the impact varies across the two periods in which critical habitat is designated and by the number of years relative to when critical habitat was first proposed.
STOCK PRICES AND EXCHANGE RATES IN AUSTRALIA: ARE COMMODITY PRICES THE MISSING LINK?
The relationship between stock prices and exchange rates is an important topic of long standing. But there are still significant gaps in our knowledge of this area, not least, the ambiguity about the sign of the effect of a change in one of these variables on the other. While there are many possible reasons for this ambiguity, one which we explore in the Australian context in this paper is the omission of commodity prices. We show that a bivariate relationship which omits commodity prices performs badly but that once commodity prices are added to the relationship, our results are plausible and robust. We also throw light on the commodity-currency issue and show that the link from the exchange rate to commodity prices is stronger and more consistent than that in the opposite direction.
Recent advances at NASA in calculating the electronic spectra of diatomic molecules
Advanced entry vehicles, such as the proposed Aero-assisted Orbital Transfer Vehicle, provide new and challenging problems for spectroscopy. Large portions of the flow field about such vehicles will be characterized by chemical and thermal nonequilibrium. Only by considering the actual overlap of the atomic and rotational lines emitted by the species present can the impact of radiative transport within the flow field be assessed correctly. To help make such an assessment, a new computer program is described that can generate high-resolution, line-by-line spectra for any spin-allowed transitions in diatomic molecules. The program includes the matrix elements for the rotational energy and distortion to the fourth order; the spin-orbit, spin-spin, and spin-rotation interactions to first order; and the lambda splitting by a perturbation calculation. An overview of the Computational Chemistry Branch at Ames Research Center is also presented
Trajectory module of the NASA Ames Research Center aircraft synthesis program ACSYNT
A program was developed to calculate trajectories for both military and commercial aircraft for use in the aircraft synthesis program, ACSYNT. The function of the trajectory module was to calculate the changes in the vehicle's flight conditions and weight, as fuel is consumed, during the flying of one or more missions. The trajectory calculations started with a takeoff, followed by up to 12 phases chosen from among the following: climb, cruise, acceleration, combat, loiter, descent, and paths. In addition, a balanced field length was computed. The emphasis was on relatively simple formulations and analytic expressions suitable for rapid computation since a prescribed trajectory had to be calculated many times in the process of converging an aircraft design, or finding an optimum configuration. The trajectory module consists of about 2500 cards and operational on a CDC 7600 computer
Cooperatives and family businesses
Cooperatives provide a significant contribution to the economy, a large proportion of the UKās economy is also supported by family businesses. Indeed, it is estimated that family businesses account for almost 25% of the UKās gross domestic product (GDP). As such these two areas are of increasing importance when considering the accountability and governance responsibilities of organisations. With new questions arising every day to challenge the contributions that cooperatives and family business make to our communities, it is essential that we have the tools to clearly demonstrate their worth. Likewise, given the importance of the role boards play in the success or failure of cooperative organisations and family businesses, and the importance of these organisations in the wider economy, it is prudent to develop some knowledge and understanding of the complexities of the way in which these boards are structured and the role that they play in achieving accountability and governance within their organisation.
The chapter considers the following: who governs; board roles and board relationships with management; board size and director selection processes; the importance of board members participation; and the input of managers in relation to accountability and governance in these two sectors. The chapter begins with a short overview of the evolution of cooperatives and what constitutes a family business. This is followed by a discussion of the organisational model and governance structures and their effectiveness
A program for calculating turbofan-driven lift-fan propulsion system performance
The performance of a turbofan-powered lift fan propulsion system for vertical takeoff and landing (VTOL) aircraft is calculated. The program formulation consists of taking bleed air from a turbofan engine, heating the bleed air in an interburner, and passing it through a tip turbine to drive a lift fan. Two options are available: bleed air from the engine exhaust, or bleed air that has passed through the engine fan only. This computer program will benefit persons unfamiliar with the thermodynamics of engine cycle analysis
PatternCoder: a programming support tool for learning binary class associations and design patterns
A comparative study of benchmarking approaches for non-domestic buildings: Part 1 ā Top-down approach
Benchmarking plays an important role in improving energy efficiency of non-domestic buildings. A review of energy benchmarks that underpin the UKās Display Energy Certificate (DEC) scheme have prompted necessities to explore the benefits and limitations of using various methods to derive energy benchmarks. The existing methods were reviewed and grouped into top-down and bottom-up approaches based on the granularity of the data used. In the study, two top-down methods, descriptive statistics and artificial neural networks (ANN), were explored for the purpose of benchmarking energy performances of schools. The results were used to understand the benefits of using these benchmarks for assessing energy efficiency of buildings and the limitations that affect the robustness of the derived benchmarks. Compared to the bottom-up approach, top-down approaches were found to be beneficial in gaining insight into how peers perform. The relative rather than absolute feedback on energy efficiency meant that peer pressure was a motivator for improvement. On the other hand, there were limitations with regard to the extent to which the energy efficiency of a building could be accurately assessed using the top-down benchmarks. Moreover, difficulties in acquiring adequate data were identified as a key limitation to using the top-down approach for benchmarking non-domestic buildings. The study suggested that there are benefits in rolling out of DECs to private sector buildings and that there is a need to explore more complex methods to provide more accurate indication of energy efficiency in non-domestic buildings
On log concavity for order-preserving and order-non-reversing maps of partial orders
Stanley used the Aleksandrov-Fenchel inequalities from the theory of nixed volumes to prove the following result. Let P be a partially ordered set with n elements, and let x ā P. If Ni* is the number of linear extensions , ā : P + (1 , 2,...,n) satisfying ā (x) = i, then the sequence N*1,ā¦,N*n is log concave (and therefore unimodal). Here the analogous results for both order-preserving and order-non-reversing maps are proved using an explicit injection. Further, if vc is the number of order-preserving maps of P into a chain of length c, then vc is shown to be 1-og concave, and the corresponding result is established for order-non-reversing maps
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