Human Factors in the Ground-Support of Small Unmanned Aircraft Systems

A growing body of research has been directed at the human factors of Unmanned Aircraft System (UAS) flight operations, yet up to now, virtually no attention has been given to the human factors of UAS maintenance. The aim of the current research program was to identify the challenges facing the maintainers of small unmanned aircraft systems. Unlike their counterparts in conventional aviation, UAS maintenance technicians are responsible for the functioning of an entire system, comprising airborne and ground-based components. Challenges include absent or poor maintenance documentation, the need to make frequent decisions about salvaging components, difficulties in troubleshooting software problems, the maintenance of radio control model aircraft components, and the potential unfamiliarity of UAS maintenance personnel with the culture and practices of the aviation industry. A “dirty dozen” list of UAS human factors is proposed

Optical analysis of plate modes in circuit boards using a multi-axis shaker table

Traditionally, vibration testing has employed single-axis shakers to replicate environmental conditions, but multi-axis environmental testing strategies have received recent attention as they may more accurately represent dynamic field environments. Here we demonstrate, for a clamped-clamped plate, the effect of testing all the axes of interest in a multi-axis shaker environmental test. The component is a printed wiring assembly (PWA) board mounted to a Team Tensor TE6-900 six degree-of-freedom shaker and an Unholtz-Dickie T1000/T2000 shaker. This study aims to determine the difference in stress states of a PWA board when tested using a single degree-of-freedom shaker (Unholtz-Dickie T1000/T2000) and a six degree-of-freedom shaker (Team Tensor TE6-900), analyzed using both component time to failure (TTF) and a scanning laser doppler vibrometer (SLDV). The PWA boards were exposed to single-axis testing using a single degree-of-freedom shaker, single-axis testing using a six degree-of-freedom shaker, and multi-axis testing using a six degree-of-freedom shaker.Mechanical Engineerin

A longitudinal and experimental study of the impact of knowledge on the bases of institutional trust

This study examined a knowledge-centered theory of institutional trust development. In the context of trust in water regulatory institutions, the moderating impact of knowledge was tested to determine if there were longitudinal changes in the bases of institutional trust as a function of increases in knowledge about a target institution. We hypothesized that as people learn about an institution with which they were previously unfamiliar, they begin to form more nuanced perceptions, distinguishing the new institution from other institutions and relying less upon their generalized trust to estimate their trust in that institution. Prior to having specific, differential information about a new institution, we expected institutional trust to be a function of generalized trust variables such as dispositional trust and trust in government. The longitudinal experiment involved 185 college students randomly assigned to one of three information conditions. Every 3 months for 15 months, participants read information about water regulatory institutions or a control institution. At each time point, participants reported their trust in and perceptions of the trust- and distrust-worthiness of the water regulatory institutions. Participants also completed measures of knowledge of water regulatory institutions, dispositional trust, and governmental trust. Our manipulation check indicated that, as expected, those in the experimental group increased in subjective knowledge of water regulatory institutions to a greater extent than those in the control condition. Consistent with our hypotheses, there was some evidence that, compared to the control group, the experimental group relied less on their general trust in government as a basis for their trust in water regulatory institutions. However, contrary to our hypotheses, there was no evidence the experimental group relied less on dispositional trust as a basis for institutional trust. There also was some evidence the experimental group\u27s trust in water regulatory institutions was less affected by fluctuations of trustworthiness (but not distrustworthiness) perceptions over time. This suggests that knowledge results in the development of more stable institutional trust attitudes, but that trustworthiness and distrustworthiness perceptions may operate somewhat differently when impacting trust in specific institutions

Analogue Models for T and CPT Violation in Neutral-Meson Oscillations

Analogue models for CP violation in neutral-meson systems are studied in a general framework. No-go results are obtained for models in classical mechanics that are nondissipative or that involve one-dimensional oscillators. A complete emulation is shown to be possible for a two-dimensional oscillator with rheonomic constraints, and an explicit example with spontaneous T and CPT violation is presented. The results have implications for analogue models with electrical circuits.Comment: 9 page

Developing and modelling of satellite docking algorithm

In this study, a stereovision sensor system hardware and an algorithm are developed to be utilized in autonomous satellite rendezvous applications. A two dimensional representative environment is also being developed consisting of omni wheel robots to test breadboard model of the sensor system in a similar proximity operation scenario. The sensor hardware is designed according to predefined requirements keeping the limitations of the satellites. The sensor is able to estimate position, orientation, linear and angular velocity of a target object whose shape and sizes are known a priori. The detection system relies on specific reference markers and extracted BRISK feature points. Both of stereo and monocular vision approaches are used to detect object and estimate its distance, followed by reverse rigid body transformation to estimate the target?s 3D location and orientation. Time difference between two subsequent frames is used for estimating linear and angular velocities. Additionally, a path-planning algorithm is developed to approach target object in an efficient way. © 2017 IEEE

Isolating the Roper Resonance in Lattice QCD

We present results for the first positive parity excited state of the nucleon, namely, the Roper resonance ($N^{{{1/2}}^{+}}$=1440 MeV) from a variational analysis technique. The analysis is performed for pion masses as low as 224 MeV in quenched QCD with the FLIC fermion action. A wide variety of smeared-smeared correlation functions are used to construct correlation matrices. This is done in order to find a suitable basis of operators for the variational analysis such that eigenstates of the QCD Hamiltonian may be isolated. A lower lying Roper state is observed that approaches the physical Roper state. To the best of our knowledge, the first time this state has been identified at light quark masses using a variational approach.Comment: 7pp, 4 figures; minor typos corrected and one Ref. adde

Signals for Lorentz Violation in Electrodynamics

An investigation is performed of the Lorentz-violating electrodynamics extracted from the renormalizable sector of the general Lorentz- and CPT-violating standard-model extension. Among the unconventional properties of radiation arising from Lorentz violation is birefringence of the vacuum. Limits on the dispersion of light produced by galactic and extragalactic objects provide bounds of 3 x 10^{-16} on certain coefficients for Lorentz violation in the photon sector. The comparative spectral polarimetry of light from cosmologically distant sources yields stringent constraints of 2 x 10^{-32}. All remaining coefficients in the photon sector are measurable in high-sensitivity tests involving cavity-stabilized oscillators. Experimental configurations in Earth- and space-based laboratories are considered that involve optical or microwave cavities and that could be implemented using existing technology.Comment: 23 pages REVTe

Penerapan Konsolidasi Beban Kerja Kluster Web server Secara Dinamis Dengan Melakukan Klasifikasi Beban Kerja Server Menggunakan Pendekatan Backpropagation Neural Network

Meningkatnya permintaan pengguna aplikasi WWW telah menyebabkan peningkatan yang sepadan dalam penggunaan sumber daya kluster server web. Penelitian ini mengkaji tentang penyediaan sumber daya web server berdasarkan parameter beban kerja server (load average CPU). Data yang digunakan adalah akses terhadap web server yang melayani applikasi Sistem Informasi Akademik Mahasiswa Universitas Brawijaya (SIAM-UB). Penggunaan sumber daya server secara maksimal (beban puncak) terjadi pada periode registrasi mahasiswa, yaitu lebih dari 65000 mahasiswa akan mengakses server SIAM secara bersamaan. Jumlah permintaan yang dilayani server dalam 1 hari dapat mencapai 1.7juta permintaan. Pada penelitian ini, dilakukan prediksi (klasifikasi) konsolidasi beban kerja CPU dalam kluster web server untuk penyediaan sumber daya server yang optimal. Prediksi konsolidasi beban kerja server diklasifikasikan menjadi 3 kelas, yaitu: Min (0-2), Medium (3-6), Maximum (n > 7). Metode backpropagation neural network (BNN) digunakan untuk memprediksi kelas konsolidasi beban kerja server berdasarkan parameter input penggunaan CPU, memory, jaringan (throughput) dan jumlah IP akses. Arsitektur BNN dengan 32 input, 2 hidden layer dengan jumlah neuoron h1 512; h2 32, 3 output, dan learning rate 0.00001, menghasilkan bobot yang mampu melakukan klasifikasi konsolidasi beban kerja CPU dengan tingkat precision 90%, tingkat sensitivity 0.9, dan tingkat akurasi 93%

Scaling solution, radion stabilization, and initial condition for brane-world cosmology

We propose a new, self-consistent and dynamical scenario which gives rise to well-defined initial conditions for five-dimensional brane-world cosmologies with radion stabilization. At high energies, the five-dimensional effective theory is assumed to have a scale invariance so that it admits an expanding scaling solution as a future attractor. The system automatically approaches the scaling solution and, hence, the initial condition for the subsequent low-energy brane cosmology is set by the scaling solution. At low energies, the scale invariance is broken and a radion stabilization mechanism drives the dynamics of the brane-world system. We present an exact, analytic scaling solution for a class of scale-invariant effective theories of five-dimensional brane-world models which includes the five-dimensional reduction of the Horava-Witten theory, and provide convincing evidence that the scaling solution is a future attractor.Comment: 17 pages; version accepted for PRD, references adde

Off-target capture data, endosymbiont genes and morphology reveal a relict lineage that is sister to all other singing cicadas

Phylogenetic asymmetry is common throughout the tree of life and results from contrasting patterns of speciation and extinction in the paired descendant lineages of ancestral nodes. On the depauperate side of a node, we find extant ´relict´ taxa that sit atop long, unbranched lineages. Here, we show that a tiny, pale green, inconspicuous and poorly known cicada in the genus Derotettix, endemic to degraded salt-plain habitats in arid regions of central Argentina, is a relict lineage that is sister to all other modern cicadas. Nuclear and mitochondrial phylogenies of cicadas inferred from probe-based genomic hybrid capture data of both target and non-target loci and a morphological cladogram support this hypothesis. We strengthen this conclusion with genomic data from one of the cicada nutritional bacterial endosymbionts, Sulcia, an ancient and obligate endosymbiont of the larger plant-sucking bugs (Auchenorrhyncha) and an important source of maternally inherited phylogenetic data. We establish Derotettiginae subfam. nov. as a new, monogeneric, fifth cicada subfamily, and compile existing and new data on the distribution, ecology and diet of Derotettix. Our consideration of the palaeoenvironmental literature and host-plant phylogenetics allows us to predict what might have led to the relict status of Derotettix over 100 Myr of habitat change in South America.Fil: Simon, Chris. University of Connecticut; Estados UnidosFil: Gordon, Eric R. L.. University of Connecticut; Estados UnidosFil: Moulds, M.S.. Australian Museum Research Institute; AustraliaFil: Cole, Jeffrey A.. Pasadena City College; Estados UnidosFil: Haji, Diler. University of Connecticut; Estados UnidosFil: Lemmon, Alan R.. Florida State University; Estados UnidosFil: Lemmon, Emily Moriarty. Florida State University; Estados UnidosFil: Kortyna, Michelle. Florida State University; Estados UnidosFil: Nazario, Katherine. University of Connecticut; Estados UnidosFil: Wade, Elizabeth J.. Curry College. Department of Natural Sciences and Mathematics; Estados Unidos. University of Connecticut; Estados UnidosFil: Meister, Russell C.. University of Connecticut; Estados UnidosFil: Goemans, Geert. University of Connecticut; Estados UnidosFil: Chiswell, Stephen M.. National Institute of Water and Atmospheric Research; Nueva ZelandaFil: Pessacq, Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Centro de Investigación Esquel de Montaña y Estepa Patagónica. Universidad Nacional de la Patagonia "San Juan Bosco". Centro de Investigación Esquel de Montaña y Estepa Patagónica; ArgentinaFil: Veloso, Claudio. Universidad de Chile; ChileFil: McCutcheon, John P.. University of Montana; Estados UnidosFil: Lukasik, Piotr. University of Montana; Estados Unidos. Swedish Museum of Natural History. Department of Bioinformatics and Genetics; Sueci