Experimental results on mass-thickness distribution in spacecraft equipment

A technique is described for evaluating the shielding properties of spacecraft equipment with respect to cosmic radiation. A gamma-ray source is used in conjunction with a scintillation detector to determine mass-thickness distribution both in plane geometry for equipment units, and in spherical geometry for given points within the spacecraft. Equations are presented for calculating mass-thickness distribution functions, and the results are compared with experimental measurements

Evidence of micro-continent entrainment during crustal accretion

Peer reviewe

Testing demand responsive shared transport services via agent-based simulations

Demand Responsive Shared Transport DRST services take advantage of Information and Communication Technologies ICT, to provide on demand transport services booking in real time a ride on a shared vehicle. In this paper, an agent-based model ABM is presented to test different the feasibility of different service configurations in a real context. First results show the impact of route choice strategy on the system performance

Counting reducible, powerful, and relatively irreducible multivariate polynomials over finite fields

We present counting methods for some special classes of multivariate polynomials over a finite field, namely the reducible ones, the s-powerful ones (divisible by the s-th power of a nonconstant polynomial), and the relatively irreducible ones (irreducible but reducible over an extension field). One approach employs generating functions, another one uses a combinatorial method. They yield exact formulas and approximations with relative errors that essentially decrease exponentially in the input size.Comment: to appear in SIAM Journal on Discrete Mathematic

Open-Source ANSS Quake Monitoring System Software

ANSS stands for the Advanced National Seismic System of the U.S.A., and ANSS Quake Monitoring System (AQMS) is the earthquake management system (EMS) that most of its member regional seismic networks (RSNs) use. AQMS is based on Earthworm, but instead of storing files on disk, it uses a relational database with replication capability to store pick, amplitude, waveform, and event parameters. The replicated database and other features of AQMS make it a fully redundant system. A graphical user interface written in Java, Jiggle, is used to review automatically generated picks and event solutions, relocate events, and recalculate magnitudes. Add‐on mechanisms to produce various postearthquake products such as ShakeMaps and focal mechanisms are available as well. It provides a configurable automatic alarming and notification system. The Pacific Northwest Seismic Network, one of the Tier 1 ANSS RSNs, has modified AQMS to be compatible with a freely available, capable, open‐source database system, PostgreSQL, and is running this version successfully in production. The AQMS Software Working Group has moved the software from a subversion repository server hosted at the California Institute of Technology to a public repository at gitlab.com. The drawback of AQMS as a whole is that it is complex to fully configure and comprehend. Nevertheless, the fact that it is very capable, documented, and now free to use, might make it an attractive EMS choice for many seismic networks

Can web crawlers revolutionize ecological monitoring?

Despite recent advances, ecosystem service monitoring is limited by insufficient data, the complexity of social-ecological systems, and poor integration of information that tracks changes in ecosystems and economic activities. However, new information and communication technologies are revolutionizing the generation of, and access to, such data. Can researchers who are interested in ecological monitoring tap into these increased flows of information by "mining" the internet to detect "early-warning" signs that may signal abrupt ecological changes? Here, we explore the possibility of using web crawlers and internet-based information to complement conventional ecological monitoring, with a special emphasis on the prospects for avoiding "late warnings"-that is, when ecosystems have already shifted to less desirable states. Using examples from coral reef ecosystems, we explore the untapped potential, as well as the limitations, of relying on web-based information to monitor ecosystem services and forewarn us of negative ecological shifts.</p

Working in temporary employment and exposure to musculoskeletal constraints

BACKGROUND: In recent years, temporary work (TW) has increased in European countries due to the greater uncertainty in the economy.AIMS: To compare the prevalence of non-specific musculoskeletal symptoms of the upper extremities (UEMSDs) and their main risk factors in blue-collar workers employed through temporary agencies (TW) and in those in permanent employment (PE). METHODS: UEMSDs occurring during the preceding 7 days were assessed using a Nordic questionnaire completed by 1493 blue-collar workers randomly included in a surveillance programme for UEMSDs (171 in TW and 1322 in PE) in a large French region. Personal factors and work-related risk factors for UEMSDs were assessed by self-administered questionnaires. RESULTS: The prevalence of UEMSDs during the preceding 7 days did not significantly differ between workers in TW or PE. However, after adjustment for age and gender, TW had a higher risk of symptoms of the wrist/hand region (OR = 1.6, 95% CI 1.04-2.6). TW was characterized by higher exposure to paced work (OR = 2.0, 95% CI 1.4-3.0), repetitive work (OR = 2.3, 95% CI 1.6-3.4), awkward postures of the wrist (OR = 1.6, 95% CI 1.2-2.4) and intensive use of vibrating hand tools (OR = 1.7, 95% CI 1.1-2.3). Workers in TW suffered from a lack of autonomy (OR = 2.5, 95% CI 1.7-3.6) and skill discretion at work (OR = 2.0, 95% CI 1.3-3.1) more frequently, but there was no difference in relation to psychological demands of the task or social support. CONCLUSIONS: Temporary workers were more frequently exposed to working time constraints, repetitive work and biomechanical constraints of the wrist/hand region when compared to permanent workers and may represent a subpopulation at particularly high risk of UEMSDs