Analysis of MMIC arrays for use in the ACTS Aero Experiment

The Aero Experiment is designed to demonstrate communication from an aircraft to an Earth terminal via the ACTS. This paper describes the link budget and antenna requirements for a 4.8 kbps full-duplex voice link at Ka-Band frequencies. Three arrays, one transmit array developed by TI and two receive arrays developed by GE and Boeing, were analyzed. The predicted performance characteristics of these arrays are presented and discussed in the paper

Dwyer Google Migration

The IT staff at Dwyer Instruments encountered several issues when switching to use Google’s business technology services. These problems included lack of a button to open a new email draft with a PDF already attached, the timestamp function in Google Sheets displaying the current time instead of the time it was entered, duplicate Google Sheets spreadsheets not maintaining protected ranges, lack of a timeline chart in Google Sheets, inability to save Gmail searches, lack of event templates in Google Calendar, and lack of a workflow management tool in Google’s business technology suite. On site personnel were asked to communicate what would help smooth the transition to the G Suite. One challenge encountered was the difficulty in publishing G-Suite add-ons to Google’s online marketplace. Another challenge is presented by the lack of examples of G-Suite add-ons. This makes it tough to create add-ons since there are few resources to go off of. A G-Suite add-on was developed to create an in-page side window in Gmail and Drive to allow attachments from selected conversations or Drive files to be attached and sent with an email. A Google Sheets add-on was also developed in order to insert the current time into a selected cell. While some needs remain outstanding, but the project made significant progress toward solving some of their IT issues

Using Ecological Land Units in a Gap Analysis for Conservation Planning in a Southwestern Ohio Watershed

Gap analysis is a method to identify insufficiency in biodiversity protection. In degraded agricultural landscapes, it requires information on the past, present, and the potential natural distribution of forest vegetation to construct a comprehensive nature reserve network. Using Geographic Information Systems (GIS), I conducted a biodiversity gap analysis to assess the representation of ecological land units (ELUs) supporting forest vegetation both within and external to the current reserve network in the Lower Twin Creek Watershed (LTCW), southwestern Ohio. I used this analysis to make conservation planning recommendations to the local park district. ELUs are based on relatively stable associations of soils, physiography, and potential natural vegetation. In heavily deforested landscapes, such as the LTCW, ELUs model a more intact functioning landscape by predicting the distribution of potential natural forest vegetation. ELUs were classified using multivariate and cluster analyses on forest canopy tree species and seven physiographic and soil variables derived from digital elevation models and a soil series map in GIS. A cluster analysis of the five most significant variables (landform, drainage, hillshade, curvature, and percent slope) influencing vegetation distribution resulted in nine discrete ELUs. They included uplands dominated by Fagus grandifolia – Acer saccharum, dry slopes dominated by Quercus spp. - Carya ovata, mesic slopes dominated by a mixed mesophytic community, and wet floodplains dominated by Platanus occidentalis – Populus deltoides. A reference ecosystem map was constructed using ArcView GIS Spatial Analyst with the five environmental variables identified in the multivariate analysis. To determine the area of forest cover in each ELU within the reserve network and the watershed as a whole, the reference ecosystem map was overlaid with a 1990 land cover type map and the reserve boundaries. The area of forest in each ELU in the reserve network was then compared to the area of forest in each ELU in the watershed as a whole and the potential natural distribution of forest cover as predicted by the reference ecosystem map to determine the percent of forest protected in each condition. The gap analysis, using the current forest distribution, indicated that the well and poorly drained upland ecosystems were underrepresented in the reserve network. A similar pattern emerged using the reference ecosystem map; however, reflecting the degree to which these upland ecosystems are deforested, to meet a 25% representation target would require three to four times more forest than existed in these ELUs in 1990. The results of the gap analysis based on the current vegetation distribution were influenced by the pattern of deforestation in the LTCW. The reference ecosystems map provided a model of an intact functioning landscape from which to establish conservation planning targets. Although the upland matrix forest ecosystems may have lower species richness per land unit area and are relatively common, restoring portions of the matrix forest may be the key to the long-term maintenance of biological diversity in the LTCW

A random field approach to spatial experiments

A spatial experiment is a comparative experiment in which the experimental units are distributed throughout a region in d-dimensional Euclidean space. The classical analysis of variance of such an experiment ignores spatial correlation among the responses. An alternative approach to the analysis of spatial experiments is proposed that does not ignore spatial correlation. In this approach, the outcome of a spatial experiment is regarded as a single realization of a collection of random variables indexed by points in d-dimensional Euclidean space. Such a collection of random variables is called a random field;In conjunction with this approach, we adopt the linear model y = X(beta) + e, where y is an nxl random vector whose elements are observable members of a d-dimensional random field F(,Y) = Y(,s): s (epsilon) (//R)(\u27d) , e is an nxl random vector whose elements are unobservable members of a random field F(,Z) = Z(,s): s (epsilon) (//R)(\u27d) satisying E Z(,s) = 0 for all s (epsilon) (//R)(\u27d), X is an nxp matrix whose elements are functions of s, and (beta) is a pxl vector of unknown parameters. The elements of the covariance matrix V of e are given by evaluating a generally non- linear function C((.),(.);(theta)) of 2d variables, where (theta) is an mxl vector of unknown parameters, at the sites where F(,Y) is observed; this func- tion is called the covariogram of F(,Y). We refer to this model as the random field linear model (RFLM);The estimation of the RFLM parameters, (beta) and (theta) by maximum likelihood approaches is studied extensively. These estimation pro- cedures are generally quite burdensome computationally; however, certain features of the RFLM can, in many cases, be exploited to reduce the amount of computation. The required amount of com- putation is primarily related to the structure of V which, in turn, is greatly affected by the spatial configuration of the sites at which F(,Y) is observed and by properties of the covariogram of F(,Y). Also inves- tigated are conditions under which the estimators of (beta) and (theta) are consistent and asymptotically normal;Estimation of treatment contrasts in a spatial experiment is of major interest. Results from pseudo-experiments based on uni- formity trial data suggest that the random field approach is superior to the classical analysis of variance and to several recently proposed nearest-neighbor methods

The Effects of Prescribed Fire on the Herbaceous Layer in the Southern Appalachian Mountains.

Prescribed fire in the southern Appalachians is a frequently used and controversial forest management practice. Research is limited on the effects of prescribed fire in the mesic southern Appalachians, where many of Tennessee\u27s rare and regionally endemic plant species occur. This study examined the effects of prescribed fire on the herbaceous layer. Field work was conducted on six previously burned sites within the Cherokee National Forest in northeast Tennessee. Complimentary non-burned sites were selected based on similarity of physical characteristics and forest structure. The numbers of herbaceous species and individuals and the total numbers of species and individuals were determined and used to compare burned and unburned forest. Following prescribed fires there were significant reductions in the number of herbaceous species and individuals. Species with myrmecochorous (ant-dispersed) seeds were markedly reduced on burned sites. Despite considerable variation among sites, the negative impact of fire on forest herbs was clearly evident

Self-Esteem, Personal Control, Optimism, Extraversion, and the Subjective Well-Being of Midwestern University Faculty

Problem and Purpose Although recent summaries of subjective well-being have illuminated four primary covariants, little research has been done that addresses the interaction and combined effects of these variables, limiting the development of theory and practice, especially in the population of university faculty. This research sought to address the interaction of self esteem, personal control, optimism, and extraversion when measured together, and how they combine in relation to subjective well-being in a sample of Midwestern university faculty. Methodology A total of 233 surveys was collected from two Midwestern university faculty populations. These surveys measured self-esteem, personal control, optimism, extraversion, subjective well-being, and several demographics. Each of these variables was analyzed using multiple regression in regard to the measure of subjective well-being. Findings Subjective well-being correlated significantly with self-esteem, a sense of personal control, and optimism, but not extraversion when measured individually. When measured together, self-esteem, a sense of personal control, and optimism were significantly correlated with subjective well-being, whereas extraversion was not significantly correlated multivariateiy Each of the variables self-esteem, personal control, optimism, and extraversion showed significant intercorrelations. When marital satisfaction and level of instruction were added to form a model in addition to the primary variables, just under 50% of the subjective well-being variance was accounted for among married faculty members. Adding marital status and instructional level to the primary variables accounted for 36% of subjective well-being variance. Conclusions Univariately, self-esteem, optimism, and personal control shared significant variance with subjective well-being. Multivariately, marital satisfaction and self-esteem shared the largest relative variance with subjective well-being. Optimism, personal control, and instructing at only one level also shared significant variance with subjective well-being multivariately. Although extraversion has shown substantial correlations with subjective well-being in other studies, it appears to be suspect in this research and may be population specific. The moderate intercorrelations between the variables show that the variables self-esteem, optimism, personal control, and extraversion do not additively relate to subjective well-being

Designs for the ATDRSS tri-band reflector antenna

Two approaches to design a tri-band reflector antenna for the Advanced TDRSS are examined. Two reflector antenna configurations utilizing frequency selective surfaces for operation in three frequency bands, S, Ku, and Ka, are proposed. Far-field patterns and the antenna feed losses were computed for each configuration. An offset-fed single reflector antenna configuration was adapted for conceptual spacecraft design. CADAM drawings were completed and a 1/13th scale model of the spacecraft was constructed

A comparison of reflector antenna designs for wide-angle scanning

Conventional reflector antennas are typically designed for up to + or - 20 beamwidths scan. An attempt was made to stretch this scan range to some + or - 300 beamwidths. Six single and dual reflector antennas were compared. It is found that a symmetrical parabolic reflector with f/D = 2 and a single circular waveguide feed has the minimum scan loss (only 0.6 dB at Theta sub 0 = 8 deg, or a 114 beamwidths scan). The scan is achieved by tilting the parabolic reflector by an angle equal to the half-scan angle. The f/D may be shortened if a cluster 7 to 19 elements instead of one element is used for the feed. The cluster excitation is adjusted for each new beam scan direction to compensate for the imperfect field distribution over the reflector aperture. The antenna can be folded into a Cassegrain configuration except that, due to spillover and blockage considerations, the amount of folding achievable is small