Rural land mobile radio market assessment and satellite and terrestrial system concepts

Market potential exists; the nature of the market in terms of service needs, usage characteristics, service requirements, and forecasting the demand to the year 2000; alternative system cncepts that show promise in addressing the identified needs, in a cost effective manner; and advanced technology requirements associated with these concepts are considered

Valuing a Spatially Diverse Non-Market Good: The Benefits of Reduced Non-Point Source Pollution in Green Bay, WI

This article presents an empirical approach to correcting for spatial interactions in stated preference data when valuing large-scale, spatially variable environmental improvements. This approach is presented in the context of a contingent valuation study estimating the benefits of reduced non-point source pollution in Green Bay, Wisconsin. The significant spatial variation of water clarity conditions in this large water body was captured using satellite-derived GIS data. This article focuses on two significant challenges: first, ensuring respondents are adequately informed of how the proposed change will impact their individual utility stream; second, dealing with the spatial effects within the estimation model. The GIS water clarity data were used to measure the initial conditions faced by each individual parcel. Including this information in the analysis significantly increased the estimated expected WTP of some individuals but decreased that of others. Some of the difference in aggregated benefits is likely due to issues of spatial correlation between properties that is unaccounted for in the simpler models.Water quality, non-point source pollution, contingent valuation, spatial correlation, Environmental Economics and Policy, Resource /Energy Economics and Policy,

Valuing a Spatially Variable Environmental Resource: Reducing Non-point Source Pollution in Green Bay, WI

This article investigates the value of reducing non-point source pollution in Green Bay, WI. Using stated preference methods, we find the lower bound on the benefits of reducing runoff enough to universally increase water clarity by four feet is greater than $9 million annually. Using a unique survey design, we show that because current water clarity in Green Bay is spatially variable, the value that a household places on this universal improvement depends on the distance of the household's residence from the Bay and on the particular geospatial location of the residence. This has important implications for estimating aggregate benefits.

Formal observation of family interaction during structured play

The present study explored how behavioral interactions in two-male sibling families during structured play may be affected by the relative ages of siblings and by the interaction situations involved. Six dyadic interaction situations of 30 minutes duration each were observed among members of 12 normal families in their homes, once a week for five consecutive weeks. Families were categorized into three groups: (a) a younger sibling and an older sibling between 2-5 years of age, (b) 2-5 year-old younger sibling and 6-9 year-old older sibling, and (c) a younger sibling and an older sibling between 6-9 years of age. The interaction situations consisted of (a) child-directed interaction with mother, (b) child-directed interaction with father, (c) child directed interaction with older sibling, (d) mother-directed interaction, (e) father-directed interaction, and (f) older sibling-directed interaction. The coding system included 34 discrete behaviors. When interaction situations were combined into parent-child and older sibling-child interaction situations, a linear combination of six behaviors correctly classified cases 89% of the time. A second stepwise discriminant analysis grouped families such that one group contained older siblings that were of preschool age and the second group contained older siblings of elementary school age. A linear combination of five behaviors was able to correctly classify cases 87% of the time. Three canonical correlations showed significant relationships between parent/sibling and child behaviors. The nature of these relationships tended to support reciprocal influence as an important element in family interaction. Results of discriminant analyses indicated that, for families with a preschool male, patterns of interaction are influenced by whether the older male sibling is of preschool or elementary school age

Accounting for Respondent Uncertainty to Improve Willingness-to-Pay Estimates

In this paper we develop an econometric model of willingness to pay that integrates data on respondent uncertainty regarding their own willingness to pay. The integration is utility consistent and does not involve calibrating the contingent responses to actual payment data, and so the approach can "stand alone". In an application to a valuation study related to whooping crane restoration, we find that this model generates a statistically lower expected WTP than the standard CV model. Moreover, the WTP function estimated with this model is not statistically different from that estimated using actual payment data, suggesting that when properly analyzed using data on respondent uncertainty, contingent valuation decisions can simulate actual payment decisions. This method allows for more reliable estimates of WTP that incorporates respondent uncertainty without the need for collecting comparable actual payment data.

Spacecraft design sensitivity for a disaster warning satellite system

A disaster warning satellite (DWS) is described for warning the general public of impending natural catastrophes. The concept is responsive to NOAA requirements and maximizes the use of ATS-6 technology. Upon completion of concept development, the study was extended to establishing the sensitivity of the DWSS spacecraft power, weight, and cost to variations in both warning and conventional communications functions. The results of this sensitivity analysis are presented

Large electronic bandwidth in solution-processable pyrene crystals: The role of close-packed crystal structure

We examine the interdependence of structural and electronic properties of two substituted pyrene crystals by means of combined spectroscopic probes and density-functional theory calculations. One derivative features n-hexyl side groups, while the other one contains branched silanyl groups. Both derivatives form triclinic crystal structures when grown from solution, but the electronic dispersion behavior is significantly different due to differences in $\pi$-$\pi$ overlap along the $a$ crystal axis. Both systems display dispersion of 0.40-0.45 eV in the valence band, suggesting a high intrinsic hole mobility. However, the dispersion is primarily along the a-axis in the silanyl-substituted derivative, but less aligned with this crystal axis in the hexyl-substituted material. This is a direct consequence of the diferences in co-facial $\pi$ electron overlap revealed by the crystallographic studies. We find that photophysical defects, ascribed to excimer-like states, point to the importance of localized trap states. Substituted pyrenes are useful model systems to unravel the interplay of crystal structure and electronic properties in organic semiconductors.Comment: 25 pages, 8 figure

Bound and free waves in non-collinear second harmonic generation

We analyze the relationship between the bound and the free waves in the noncollinear SHG scheme, along with the vectorial conservation law for the different components arising when there are two pump beams impinging on the sample with two different incidence angles. The generated power is systematically investigated, by varying the polarization state of both fundamental beams, while absorption is included via the Herman and Hayden correction terms. The theoretical simulations, obtained for samples which are some coherence length thick show that the resulting polarization mapping is an useful tool to put in evidence the interference between bound and free waves, as well as the effect of absorption on the interference patternComment: 10 pages, 7 figure. to be published on Optics Expres

Astrobee Guest Science Interface

At the end of 2018, Astrobee will launch three free-flying robots that will navigate the entire US segment of the ISS (International Space Station) and serve as a payload facility. The mechanical and electrical interfaces are now established and several payloads are being developed. Payload Interface: Astrobee is designed to host third party guest science program payloads (GSP payloads). Some GSP payloads may be software only, such as the Zero Robotics Finals Competition, which is currently hosted on SPHERES, and which will transition to Astrobee in 2019. Several GSP payloads with custom hardware, such as the Advanced Exploration Systems (AES) Logistics Reduction and Repurposing (LRR) Project RFID reader, are already under development. These payloads will attach in the Astrobee payload bay