An Online Social Networking Experiment

Online social networking is a pervasive but empirically understudied phenomenon. Strong public opinions on its consequences exist but are backed up by little empirical evidence and almost no causally conclusive, experimental research. The current study tested the psychological effects of posting status updates on Facebook using an experimental design. For 1 week, participants in the experimental condition were asked to post more than they usually do, whereas participants in the control condition received no instructions. Participants added a lab “Research Profile” as a Facebook friend allowing for the objective documentation of protocol compliance, participants’ status updates, and friends’ responses. Results revealed (1) that the experimentally induced increase in status updating activity reduced loneliness, (2) that the decrease in loneliness was due to participants feeling more connected to their friends on a daily basis, and (3) that the effect of posting on loneliness was independent of direct social feedback (i.e., responses) by friends

The Fine Guidance Sensor, An Electronic Scanning Star Tracker

The advent of space exploration has placed hitherto unheard of requirements on accuracy and precision sensing devices for guidance and attitude control. The necessity for high reliability, due to non-repairability, required new approaches to this design problem. Rather than try to improve upon existing systems, components, and approaches, a totally new concept evolved which eliminates the mechanical rotors and reticles of yesterday. Instead, a totally new breed of electronic scanning star sensor resulted. This paper describes one such device, a Boresighted Star and Planet Tracker developed for precise attitude sensing and control of an experimental sounding rocket. Discussed are the major elements of the basic sensing system, optics, detector, and electronics. The heart of the new sensor is the electronic scanning multiplier phototube, a small, rugged, highly accurate and highly reliable device. Electronic circuit design to enhance accuracy and precision is outlined

Integration of System-Dynamics, Aspect-Programming, and Object-Orientation in System Information Modeling

Contemporary information modeling of enterprise systems only focuses on the technical aspect of the systems, though it is known that they are social-technical (socio-tech) systems in essence. In fact, there are many lessons that can be learned from failures in the management of enterprise systems, which range from a small one (e.g., failure to install a printer driver) to a large one (e.g., nuclear power plant post-accident management). This paper, therefore, proposes that the enterprise system should be viewed as a socio-tech system. The paper presents a novel integrated approach to information modeling of socio-tech enterprise systems. In particular, the approach integrates object-orientation, systems-dynamics (as a means to represent high-level dynamics), and aspect-programming. The paper discusses an example to illustrate how the proposed approach works. © 2012 IEEE.published_or_final_versio

Aerodynamic and Aeroacoustic Performance of Small UAV Propellers in Static Conditions

The proliferation of small multi-rotor UAVs in commercial, recreational, and surveillance spheres has garnered significant interest in the noise produced by these vehicles. The current research aims to study the relationship between the aerodynamic performance and acoustic characteristics of small-scale UAV propellers. Three commercially available propellers for the DJI Phantom 2/3 UAV were selected for preliminary development and validation of an aeroacoustic experimental test setup and associated data reduction methods. Propeller thrust, torque, and power measurements were recorded at static conditions. Upon successful validation of the test bench, acoustic measurements were taken at the propeller disk’s upstream and in-plane locations. The power spectral density of these acoustic signals was estimated using the modified periodogram (Welch’s) method to identify frequency content and calculate sound pressure levels (SPLs) at each of the observation locations. Additionally, time-frequency analysis verified the periodogram results and identified possible sources of transient noise at static thrust. These methods found the nonrotor noise to be a major contributor to the SPL at higher frequencies and the propeller noise dominating the SPL spectra at the lower frequencies. Experimental thrust, torque, power, and sound pressure level (SPL) data were then compared for each propeller to identify relationships between aerodynamic performance and acoustic characteristics with variations in propeller geometry and blade loading

Optical Guidance System /OGS/ for rendezvous and docking Final report

Optical guidance system for Apollo rendezvous and dockin

Rolling-sliding laboratory tests of friction modifiers in dry and wet wheel-rail contacts

Friction management has been carried out extensively in the majority of railway networks in the last few years. A popular practice is the application of friction modifiers to increase the adhesion level in contaminated wheel-rail contacts. Two friction modifiers have particularly been used or tested on several railway networks as adhesion enhancers to facilitate the traction and braking operation under poor adhesion conditions. However, for assessment of the performance the railway operators and infrastructure managers mostly rely on practical observations that do not elucidate completely the effectiveness and side effects of these adhesion enhancers. In this paper, the constituents of the two friction modifiers are identified and the solid components are analyzed. A twin-disk roller rig has been used to study their performance in dry and wet contacts under closely controlled laboratory conditions. The adhesion characteristics of both friction modifiers are examined for different slip ratios. Furthermore, the wheel and rail disks are examined after a series of dry tests to analyze the mass loss, the surface damage, the change in surface hardness and roughness, and the subsurface deformation caused by the friction modifiers compared to dry clean contacts. (C) 2009 Elsevier B.V. All rights reserved

Sneak preview of the Saskatchewan soil information system (SKSIS)

Non-Peer Reviewe

Saskatchewan Soil Information System (SKSIS)-The Launch!

Non-Peer Reviewe

Um estudo da legislação e das métricas do setor elétrico brasileiro para fomentar a digitalização e a descentralização do mercado de energia

CIES2020 - XVII Congresso Ibérico e XIII Congresso Ibero-americano de Energia SolarRESUMO: A energia elétrica gerada de forma distribuída deve ser transacionada de forma segura e eficaz, o que pode ser obtido por meio da aplicação da tecnologia blockchain no setor elétrico. Objetiva-se com este artigo trabalhar com questões legais relacionadas ao setor de comercialização de energia elétrica indicando as necessidades de alterações na legislação e na regulamentação, a fim de possibilitar a aplicação da tecnologia blockchain. Assim como, objetiva-se propor métricas relacionadas à aplicação de blockchain no mercado de comercialização de energia elétrica brasileiro para promover a digitalização e o aprimoramento de seus processos. O estudo fundamenta-se e desenvolve-se por revisão documental do ambiente regulatório brasileiro; e por revisão documental e bibliográfica sobre o mercado de comercialização de energia elétrica. Os resultados são indicações de alterações na legislação e na regulamentação, e métricas de impactos para aplicação da tecnologia blockchain no mercado de comercialização de energia elétrica brasileiro.ABSTRACT: The electric energy generated in a distributed manner must be transacted safely and effectively. It can be obtained through the application of blockchain technology in the electric sector. The aim of this article is to work with legal issues related to the electric energy trading sector. It will be possible indicating the necessity for changes in legislation and regulation to enable the application of blockchain technology in this sector. As well, it aims to propose metrics related to the application of blockchain in the Brazilian electric energy trading market for the purpose of promote the digitization and improvement of its processes. This study is based and developed by documentary review of the Brazilian regulatory environment; and by documentary and bibliographic review about the electric energy commercialization market. The results are indications of changes in legislation and regulations, and metrics of impacts for the application of blockchain technology in the Brazilian electric energy commercialization market.info:eu-repo/semantics/publishedVersio

[(11)C]PiB PET in Gerstmann-Sträussler-Scheinker disease

Gerstmann-Sträussler-Scheinker Disease (GSS) is a familial neurodegenerative disorder characterized clinically by ataxia, parkinsonism, and dementia, and neuropathologically by deposition of diffuse and amyloid plaques composed of prion protein (PrP). The purpose of this study was to evaluate if [(11)C]Pittsburgh Compound B (PiB) positron emission tomography (PET) is capable of detecting PrP-amyloid in PRNP gene carriers. Six individuals at risk for GSS and eight controls underwent [(11)C]PiB PET scans using standard methods. Approximately one year after the initial scan, each of the three asymptomatic carriers (two with PRNP P102L mutation, one with PRNP F198S mutation) underwent a second [(11)C]PiB PET scan. Three P102L carriers, one F198S carrier, and one non-carrier of the F198S mutation were cognitively normal, while one F198S carrier was cognitively impaired during the course of this study. No [(11)C]PiB uptake was observed in any subject at baseline or at follow-up. Neuropathologic study of the symptomatic individual revealed PrP-immunopositive plaques and tau-immunopositive neurofibrillary tangles in cerebral cortex, subcortical nuclei, and brainstem. PrP deposits were also numerous in the cerebellar cortex. This is the first study to investigate the ability of [(11)C]PiB PET to bind to PrP-amyloid in GSS F198S subjects. This finding suggests that [(11)C]PiB PET is not suitable for in vivo assessment of PrP-amyloid plaques in patients with GSS