Active control of spacecraft charging on ATS-5 and ATS-6

Effects on spacecraft ground potential of active emission of charged particles are being investigated through experiments using the ATS-5 and ATS-6 spacecraft. Each spacecraft is equipped with ion engine neutralizers which emit low energy charged particles. Despite great differences in design between the two spacecraft, they attain similar potentials in similar environments. Therefore, effects on spacecraft potential of neutralizer operations can be used to compare the effects of operating the two different neutralizers (hot wire filament and plasma bridge). The neutralizers on both spacecraft were operated in eclipse. Results of these operations are presented and spacecraft responses compared

Low-cost, aerial photographic inventory of tidal wetlands

There are no author-identified significant results in this report

Application of asymptotic expansions of maximum likelihood estimators errors to gravitational waves from binary mergers: the single interferometer case

In this paper we describe a new methodology to calculate analytically the error for a maximum likelihood estimate (MLE) for physical parameters from Gravitational wave signals. All the existing litterature focuses on the usage of the Cramer Rao Lower bounds (CRLB) as a mean to approximate the errors for large signal to noise ratios. We show here how the variance and the bias of a MLE estimate can be expressed instead in inverse powers of the signal to noise ratios where the first order in the variance expansion is the CRLB. As an application we compute the second order of the variance and bias for MLE of physical parameters from the inspiral phase of binary mergers and for noises of gravitational wave interferometers . We also compare the improved error estimate with existing numerical estimates. The value of the second order of the variance expansions allows to get error predictions closer to what is observed in numerical simulations. It also predicts correctly the necessary SNR to approximate the error with the CRLB and provides new insight on the relationship between waveform properties SNR and estimation errors. For example the timing match filtering becomes optimal only if the SNR is larger than the kurtosis of the gravitational wave spectrum

Learning with Biased Complementary Labels

In this paper, we study the classification problem in which we have access to easily obtainable surrogate for true labels, namely complementary labels, which specify classes that observations do \textbf{not} belong to. Let $Y$ and $\bar{Y}$ be the true and complementary labels, respectively. We first model the annotation of complementary labels via transition probabilities $P(\bar{Y}=i|Y=j), i\neq j\in\{1,\cdots,c\}$, where $c$ is the number of classes. Previous methods implicitly assume that $P(\bar{Y}=i|Y=j), \forall i\neq j$, are identical, which is not true in practice because humans are biased toward their own experience. For example, as shown in Figure 1, if an annotator is more familiar with monkeys than prairie dogs when providing complementary labels for meerkats, she is more likely to employ "monkey" as a complementary label. We therefore reason that the transition probabilities will be different. In this paper, we propose a framework that contributes three main innovations to learning with \textbf{biased} complementary labels: (1) It estimates transition probabilities with no bias. (2) It provides a general method to modify traditional loss functions and extends standard deep neural network classifiers to learn with biased complementary labels. (3) It theoretically ensures that the classifier learned with complementary labels converges to the optimal one learned with true labels. Comprehensive experiments on several benchmark datasets validate the superiority of our method to current state-of-the-art methods.Comment: ECCV 2018 Ora

The Impact of Socioeconomic Factors and Meat Attributes on Willingness to Pay for Locally or Regionally Produced Livestock Products in Alabama

Socioeconomic factors and meat attributes are believed to influence willingness to pay for specially produced livestock products. However, limited research has been done on this subject particularly in Alabama. The study, therefore, assessed the impact of socioeconomic factors and meat attributes on willingness to pay for locally or regionally produced livestock products in Alabama. Data were obtained from a convenience sample of participants from South Central Alabama, and were analyzed using descriptive statistics and ordinal logistic analysis. The socioeconomic characteristics reflected more middle-aged or younger persons, with a fairly good education, and with low to moderate household incomes. A majority thought using chemicals in locally or regionally produced beef or goat meat was a serious hazard. Therefore, many were willing to pay more for meat certified as locally or regionally produced. Also, most agreed or strongly agreed with statements on meat attributes. The ordinal logistic results revealed that household size, safety (safe to consume), no difference (in safety), and hygiene had significant relationships with willingness to pay more for meat certified as locally or regionally produced. Keywords: socioeconomic factors, meat attributes, local or regional, willingness to pay, livestock product

Assessing Alabama Consumer Attitudes and Beliefs About Locally or Regionally Produced Livestock and Products

Abstract Local and regional food production has gained increased interest of consumers in recent years. The study, therefore, focused on assessing consumer attitudes and beliefs on local or regional livestock products. Data were obtained from a convenience sample of 432 participants from South Central Alabama, and were analyzed using descriptive statistics, including chi-square tests. A majority of respondents thought using chemicals and additives in locally or regionally produced beef or goat meat was a serious hazard. Therefore, many were willing to pay more for meat certified as locally or regionally produced. Also, most agreed or strongly agreed with statements on meat attributes. Chi-square tests showed that gender, education, and household income had significant relationships with willingness to pay more for meat certified as locally or regionally produced. Furthermore, safety, no difference, affordability, desirability, and hygiene had significant relationships with willingness to pay more for meat certified as locally or regionally produced. Keywords: Consumers, Attitudes and Beliefs, Local and Regional, Willingness to Pay, Livestock Product

Evaluating the Economic Feasibility of Producing Broilers on Pasture and in a Conventional Production System

The demand for pasture raised poultry is increasing because of the perception that it is healthier and tastier than conventionally raised poultry. In order to meet this demand, some producers are considering switching from the conventional to the pasture system to take advantage of this niche market. Therefore, the objective of the study was to determine the economic viability of rearing broilers in a pastured poultry system (PPS) versus a conventional poultry system (CPS). Each of these systems was replicated three times with 60 birds per treatment in a study lasting seven weeks. Data were collected on costs of inputs, and others estimated. The mean net returns for PPS and CPS were, respectively, $56.44 and -$92.02. The break-even prices were, respectively, $10.89 for PPS and$11.87 for CPS. Also, the benefit/cost ratio was 1.103 for PPS and 0.845 for CPS. The paired t-test for the benefit/cost ratios indicated a significant difference (p< 0.05) between PPS and CPS. PPS was deemed more feasible than CPS. Hence, it was recommended that the former system is more appropriate for small and limited resource producers, and that technical assistance should be provided to them regarding PPS. Keywords: Pastured poultry, Conventional poultry, Economic feasibility, Broiler

An Analysis of the Characteristics and Practices of Selected Alabama Small Livestock Producers: A Focus on Economics and Marketing

Abstract The study examined the characteristics and practices of small livestock producers, focusing on economics and marketing. Data were obtained from a convenience sample of 121 small producers from several South Central Alabama counties, and were analyzed using descriptive statistics, including chi-square tests. The socioeconomic characteristics reflected a higher proportion of part-time farmers; a higher proportion with at most a two-year/technical degree or some college education; and a higher proportion with $40,000 or less annual household income. A majority had been farming more than thirty years, and most had small herds. Also, very few made profits; many sold animals live on-farm or at auction/stockyard, and kept records. The chi-square tests showed that farming status, gender, race/ethnicity, age, education, and household income had statistically significant relationships with selected farm, economic, and marketing characteristics. Educational programs should be implemented in the study area emphasizing economics and marketing, and taking into consideration socioeconomic factors

Impact of Socioeconomic Factors on Florida Consumers\u27 Perceptions on Use of Chemical in Locally or Regionally Produced Livestock Products

Abstract The use of chemicals in livestock production has been an issue for consumers for several decades. This study, therefore, assessed the impact of socioeconomic factors on Florida consumers’ perceptions on the use of chemicals in locally or regionally produced livestock products. Data were collected from a sample of 404 participants from several Florida counties and were analyzed using descriptive statistics and ordinal logistic analysis. Most of the respondents were of the opinion that using chemicals in locally or regionally produced and sold beef or goat meat was a serious or somewhat serious hazard. The ordinal logistic regression results showed that several socioeconomic factors, such as household size, gender, age, and education had significant effects on pesticide residues; antibiotics; artificial fertilizers; additives and preservatives, and artificial coloring. It was recommended that producers and processors should minimize the use of chemicals in livestock products as this has both short- and long-term benefits. Keywords: Socioeconomic Factors, Chemicals, Consumer Perceptions, Locally or Regionally Produced, Livestock Product

An Examination of Selected Small Livestock Producers’ Implementation of Identified Best Practices in Alabama

Getting small farmers to adopt “best practices” has been a key challenge in general, but particularly, in the Southeastern U.S. This study focused on selected small livestock producers’ implementation identified best practices in Alabama. Data were obtained through interviews from twelve producers in, primarily, selected South Central Alabama counties emphasizing best practices as well as other production indicators. The subjects were mainly beef cattle and meat goat producers. The identified best practices were: rotational grazing, soil testing, quarantining, deworming, veterinary services, and record keeping. The data were analyzed using descriptive narrative and simple statistics. The demographics showed more male than female producers, and more meat goat producers than beef cattle producers. Also, the results revealed that the commonest best practice was deworming; followed by quarantining, soil testing and record keeping, and rotational grazing. Using veterinary services was the least practiced best practice; most producers chose to provide their own animal health services. The results provide an opportunity for assistance providers to educate producers on the importance of adopting the best practices. Keywords: Small Producers, Livestock Producers, Best Practices, Case Study