45 research outputs found
Securing a Wireless Site Network to Create a BIM-allied Work-front
The Building Information Model (BIM) serves as a framework to align all the project-related data, providing interoperability to store and retrieve information interactively. Unfortunately, the construction site itself is excluded from this interaction as the large amount of data requires high data transfer rates and ruggedized hardware. However, advanced wireless communication technologies open radically new avenues to relay large amounts of data automatically and in near real-time. Construction could be a key beneficiary of these advancements. Wireless communication integrated with BIM, GPS and the Internet is able to provide the backbone necessary for creating intelligent systems, supporting the designer in his or her office as well as workers on the work-front. This paper presents a study that documents the development and testing of prototypes designed to facilitate information sharing at the field-level during construction. The main system constitutes an information hub, called the eCKiosk, connecting “senders and receivers” both on-site as well as off-site. The system design is discussed and some of the main modules are demonstrated. Since the electronic Kiosk depends on robust connections to the wireless devices distributed across the site, reliable connectivity is essential. For this reason, the discussion includes a study of the electronic signals behaviour in an ever-changing construction site. Measurements of the signal strengths during excavation and concrete work are presented and compared with theoretical calculations used to predict wave propagation. The results show how present models overestimate signal attenuation patterns on the construction site. This is important for designing a reliable and secure wireless site networks to link BIM to the work-front
Broadband Quasi-Periodic Radio and X-ray Pulsations in a Solar Flare
We describe microwave and hard X-ray observations of strong quasiperiodic
pulsations from the GOES X1.3 solar flare on 15 June 2003. The radio
observations were made jointly by the Owens Valley Solar Array (OVSA), the
Nobeyama Polarimeter (NoRP), and the Nobeyama Radioheliograph (NoRH). Hard
X-ray observations were made by the Ramaty High Energy Solar Spectroscopic
Imager (RHESSI). Using Fourier analysis, we study the frequency- and
energy-dependent oscillation periods, differential phase, and modulation
amplitudes of the radio and X-ray pulsations. Focusing on the more complete
radio observations, we also examine the modulation of the degree of circular
polarization and of the radio spectral index. The observed properties of the
oscillations are compared with those derived from two simple models for the
radio emission. In particular, we explicitly fit the observed modulation
amplitude data to the two competing models. The first model considers the
effects of MHD oscillations on the radio emission. The second model considers
the quasi-periodic injection of fast electrons. We demonstrate that
quasiperiodic acceleration and injection of fast electrons is the more likely
cause of the quasiperiodic oscillations observed in the radio and hard X-ray
emission, which has important implications for particle acceleration and
transport in the flaring sources.Comment: ApJ, accepte
Reply to Komatsu et al.: From local social mindfulness to global sustainability efforts?
Komatsu et al. (1) argue that Van Doesum et al. (2)
may have overlooked the role of GDP in reporting a
positive association between social mindfulness
(SoMi) and the Environmental Performance Index
(EPI) at country level. Although the relationship
between EPI and SoMi is relatively weaker for countries with higher GDP, that does not imply that the
overall observed relationship is a statistical artifact.
Rather, it implies that GDP may be a moderator of
the relationship between EPI and SoMi. The
observed correlation is a valid result on average
across countries, and the actual effect size would, at
least to some degree, depend on GDP
Reply to Nielsen et al.: Social mindfulness is associated with countries' environmental performance and individual environmental concern.
Nielsen et al. (1) argue that Van Doesum et al. (2)
need to consider three points for their interpretation
of a positive association between individual-level
social mindfulness (SoMi) and environmental performance (EPI) at the country level (3). The association
is weaker when 1) it is controlled for GDP and 2)
when the data of three countries are removed; also,
3) the data do not address the association between
SoMi and individual-level environmental concern.
We discuss these points in turn
Social mindfulness and prosociality vary across the globe
Humans are social animals, but not everyone will be mindful of others to the same extent. Individual differences have been found, but would social mindfulness also be shaped by one’s location in the world? Expecting cross-national differences to exist, we examined if and how social mindfulness differs across countries. At little to no material cost, social mindfulness typically entails small acts of attention or kindness. Even though fairly common, such low-cost cooperation has received little empirical attention. Measuring social mindfulness across 31 samples from industrialized countries and regions (n = 8,354), we found considerable variation. Among selected country-level variables, greater social mindfulness was most strongly associated with countries’ better general performance on environmental protection. Together, our findings contribute to the literature on prosociality by targeting the kind of everyday cooperation that is more focused on communicating benevolence than on providing material benefits
Review of Coronal Oscillations - An Observer's View
Recent observations show a variety of oscillation modes in the corona. Early
non-imaging observations in radio wavelengths showed a number of fast-period
oscillations in the order of seconds, which have been interpreted as fast
sausage mode oscillations. TRACE observations from 1998 have for the first time
revealed the lateral displacements of fast kink mode oscillations, with periods
of ~3-5 minutes, apparently triggered by nearby flares and destabilizing
filaments. Recently, SUMER discovered with Doppler shift measurements loop
oscillations with longer periods (10-30 minutes) and relatively short damping
times in hot (7 MK) loops, which seem to correspond to longitudinal slow
magnetoacoustic waves. In addition, propagating longitudinal waves have also
been detected with EIT and TRACE in the lowest density scale height of loops
near sunspots. All these new observations seem to confirm the theoretically
predicted oscillation modes and can now be used as a powerful tool for
``coronal seismology'' diagnostic.Comment: 5 Figure
Reply to Komatsu et al.: from local social mindfulness to global sustainability efforts?
Komatsu et al. (1) argue that Van Doesum et al. (2) may have overlooked the role of GDP in reporting a positive association between social mindfulness (SoMi) and the Environmental Performance Index (EPI) at country level. Although the relationship between EPI and SoMi is relatively weaker for countries with higher GDP, that does not imply that the overall observed relationship is a statistical artifact. Rather, it implies that GDP may be a moderator of the relationship between EPI and SoMi. The observed correlation is a valid result on average across countries, and the actual effect size would, at least to some degree, depend on GDP.Social decision makin
Reply to Nielsen et al.: social mindfulness is associated with countries’ environmental performance and individual environmental concern
Nielsen et al. (1) argue that Van Doesum et al. (2) need to consider three points for their interpretation of a positive association between individual-level social mindfulness (SoMi) and environmental performance (EPI) at the country level (3). The association is weaker when 1) it is controlled for GDP and 2) when the data of three countries are removed; also, 3) the data do not address the association between SoMi and individual-level environmental concern. We discuss these points in turn.Social decision makin
Traveling waves and pattern formation for spatially discrete bistable reaction-diffusion equations (survey)
Analysis and Stochastic