Showing papers by "UTC Aerospace Systems published in 2012"

Occurrence of viruses within Tasmanian vegetable crops and identification of a novel Polerovirus infecting pea

Abstract: Tasmanian vegetable crops (broccoli, carrots, cauliflower, common bean, and pea) were tested for virus infection with Potyviruses (all crops), members of the Luteoviridae (all except carrot), Alfalfa mosaic virus (all except brassicas), Cucumber mosaic virus (all except carrot and cauliflower), Subterranean clover stunt virus (legumes only), Tomato spotted wilt virus (legumes only) and Cauliflower mosaic virus (brassicas only) over three seasons (2007–2010). Low (and sporadic) incidence of each virus (or virus group) was found in pea crops. Only Luteovirid and SCSV infections were found in bean crops at low frequency and incidence. Virus infection was not detected in carrot crops. Broccoli crops recorded generally low incidence of all four viruses or groups tested for, whilst cabbage crops recorded very low incidence of CaMV only. In the pea and broccoli crops members of the Luteoviridae were the most prevalent viruses detected. Samples that tested positive for generic Potyvirus and Luteoviridae tests were retested using virus specific antiserum and/or RT-PCR. Potyvirus detections (from pea crops in the first year of testing) were due to infection with Pea seed-borne mosaic virus (PSbMV). These samples were all sourced from a single imported seed line. Subsequent testing over the next two seasons failed to show evidence of PSbMV which may have been eliminated with destruction of the seed source. Molecular analyses of a selection of Luteovirid isolates revealed most infections were due to Turnip yellows virus with five isolates from pea belonging to a putative novel Polerovirus species with closest homology to Cucurbit aphid-borne yellows virus.

Bulk soil moisture estimation using CosmOz cosmic ray sensor and ANFIS

Abstract: This paper investigates a novel technique based on Fuzzy C means (FCM) algorithm and Adaptive Neuro-Fuzzy Inference System (ANFIS) to estimate soil moisture using cosmic ray soil moisture probes deployed across Australia. These probes are a brand new sensing technology still being evaluated. Preliminary results indicate ANFIS is able to estimate soil moisture with 90% accuracy.

Rapid Cycle Amine (RCA 2.0) System Development

Abstract: The Rapid Cycle Amine (RCA) system is a low-power assembly capable of simultaneously removing carbon dioxide (CO2) and humidity from an influent air steam and subsequent regeneration when exposed to a vacuum source. Two solid amine sorbent beds are alternated between an uptake mode and a regeneration mode. During the uptake mode, the sorbent is exposed to an air steam (ventilation loop) to adsorb CO2 and water (H2O) vapor, whereas during the regeneration mode, the sorbent rejects the adsorbed CO2 and H2O vapor to a vacuum source. The two beds operate such that while one bed is in the uptake mode, the other is in the regeneration mode, thus continuously providing an on-service sorbent bed by which CO2 and humidity may be removed. A novel valve assembly provides a simple means of diverting the process air flow through the uptake bed while simultaneously directing the vacuum source to the regeneration bed. Additionally, the valve assembly is designed to allow for switching between uptake and regeneration modes with only one moving part while minimizing gas volume losses to the vacuum source by means of an internal pressure equalization step during actuation. The process can be controlled by a compact, low-power controller design with several modes of operation available to the user. Together with NASA Johnson Space Center, Hamilton Sundstrand Space Systems International, Inc. has been developing RCA 2.0 based on performance and design feedback on several sorbent bed test articles and valve design concepts. A final design of RCA 2.0 was selected in November 2011 and fabricated and assembled between March and August 2012, with delivery to NASA Johnson Space Center in September 2012. This paper provides an overview of the RCA system design and results of pre-delivery testing.

Distributed orthogonal STBC for amplify and forward cooperative network under imperfect synchronization

Abstract: Most research dealing with the issue of imperfect synchronization in D-STBC cooperative networks assume that all relay nodes receive the symbols correctly while employing a decode and forward (DF) relaying protocol. It is an unrealistic assumption as detection errors at the relay nodes are inevitable. In this paper this assumption will be relaxed, and an amplify and forward (AF) protocol is used. To achieve a low complexity yet effective receiver the paper proposes a modified version of a successive interference cancellation (SIC) detector to combat the synchronization errors induced by imperfections. Our numerical simulations show that the SIC detector can mitigate the performance system degradation in just a small number of iterations.

Towards optimal design of avionics networking infrastructures

Abstract: In this work, we address the problem of transforming the process of making design decisions for networking infrastructures in avionics systems from an ad-hoc approach to a systematic, structured approach. Given a set of data communications needs, the goal is to show how a variety of candidate network topologies (e.g. multi-drop bus vs. hub-and-spoke) and avionics protocols such as ARINC 664, MIL-STD-1553B, ARINC 429 and ARINC 825 (CAN), would perform over a continuum of values, and select the best configuration for a given target platform. We have developed a simulation tool based on OPNET which (a) emulates each of the above standards (b) identifies strengths and limitations of each one in handling a given load and characterizes their behavior over a continuum of values, and (c) provides guidelines for the optimal choice to meet the given requirements.