142 research outputs found
The Meaning of Patent Citations: Report on the NBER/Case-Western Reserve Survey of Patentees
A survey of recent patentees was conducted to elicit their perceptions regarding the importance of their inventions, the extent of their communication with other inventors, and the relationship of both importance and communication to observed patent citations. A cohort of 1993 patentees were asked specifically about 2 patents that they had cited, and a third placebo' patent that was similar but which they did not cite. One of the two cited inventors was also surveyed. We find that inventors report significant communication, at least some of which is in forms that suggests spillovers from the cited inventor to the citing inventor. The perception of such communication was substantively and statistically significantly greater for the cited patents than for the placebos. There is, however, a large amount of noise in citations data; it appears that something like one-half of all citations do not correspond to any perceived communication, or even necessarily to a perceptible technological relationship between the inventions. We also find a significant correlation between the number of citations a patent received and its importance (both economic and technological) as perceived by the inventor.
Evidence from Patents and Patent Citations on the Impact of NASA and Other Federal Labs on Commercial Innovation
We explore the commercialization of government-generated technology by analyzing patents awarded to the U.S. government and the citations to those patents from subsequent patents. We use information on citations to federal patents in two ways: (1) to compare the average technological impact of NASA patents, other Federal' patents, and a random sample of all patents using measures of importance' and generality;' and (2) to trace the geographic location of commercial development by focusing on the location of inventors who cite NASA and other federal patents. We find, first, that the evidence is consistent with increased effort to commercialize federal lab technology generally and NASA specifically. The data reveal a striking NASA golden age' during the second half of the 1970s which remains a puzzle. Second, spillovers are concentrated within a federal lab complex of states representing agglomerations of labs and companies. The technology complex links five NASA states through patent citations: California, Texas, Ohio, DC/Virginia-Maryland, and Alabama. Third, qualitative evidence provides some support for the use of patent citations as proxies for both technological impact and knowledge spillovers.
The ANU WiFeS SuperNovA Program (AWSNAP)
This paper presents the first major data release and survey description for
the ANU WiFeS SuperNovA Program (AWSNAP). AWSNAP is an ongoing supernova
spectroscopy campaign utilising the Wide Field Spectrograph (WiFeS) on the
Australian National University (ANU) 2.3m telescope. The first and primary data
release of this program (AWSNAP-DR1) releases 357 spectra of 175 unique objects
collected over 82 equivalent full nights of observing from July 2012 to August
2015. These spectra have been made publicly available via the WISeREP supernova
spectroscopy repository. We analyse the AWSNAP sample of Type Ia supernova
spectra, including measurements of narrow sodium absorption features afforded
by the high spectral resolution of the WiFeS instrument. In some cases we were
able to use the integral-field nature of the WiFeS instrument to measure the
rotation velocity of the SN host galaxy near the SN location in order to obtain
precision sodium absorption velocities. We also present an extensive time
series of SN 2012dn, including a near-nebular spectrum which both confirms its
"super-Chandrasekhar" status and enables measurement of the sub-solar host
metallicity at the SN site.Comment: Submitted to Publications of the Astronomical Society of Australia
(PASA). Spectra publicly released via WISeREP at
http://wiserep.weizmann.ac.il
Recommended from our members
Cover-based allometric estimate of aboveground biomass of a non-native, invasive annual grass (Bromus tectorum L.) in the Great Basin, USA
Cheatgrass (Bromus tectorum L.) presence in the Great Basin is associated with an increase in fire frequency andsize, likely due to increased spatial continuity of fine fuel biomass. Measurements of the extent and cover ofcheatgrass are steadily improving, but the strength of the relationship between cover and aboveground biomass(AGB) is unclear. An allometric equation that can reliably convert cover to AGB of cheatgrass would allow forimproved incorporation of regional estimates of cover into models of fire activity, carbon storage, and net pri­mary productivity, all of which rely on biomass. We measured cover and AGB of cheatgrass at 60 locations in thenorth-central Great Basin and used these measurements to model the relationship. We found a strong, linearrelationship between the percent cover and AGB, which was improved after square root transformation of bothcover and AGB, and after incorporating the number of days after peak NDVI that the biomass and cover weremeasured. These results show that AGB of cheatgrass can be reliably estimated from cover. It is likely thatallometric equations based on cover will be effective for other grass species, but care must be taken to account forphenology (e.g., peak NDVI) in the estimation.</p
Recommended from our members
Designing count‐based studies in a world of hierarchical models
Abstract:
Advances in hierarchical modeling have improved estimation of ecological parameters from count data, especially those quantifying population abundance, distribution, and dynamics by explicitly accounting for observation processes, particularly incomplete detection. Even hierarchical models that account for incomplete detection, however, cannot compensate for data limitations stemming from poorly planned sampling. Ecologists therefore need guidance for planning count‐based studies that follow established sampling theory, collect appropriate data, and apply current modeling approaches to answer their research questions. We synthesize available literature relevant to guiding count‐based studies. Considering the central historical and ongoing contributions of avian studies to ecological knowledge, we focus on birds as a case study for this review, but the basic principles apply to all populations whose members are sufficiently observable to be counted. The sequence of our review represents the thought process in which we encourage ecologists to engage 1) the research question(s) and population parameters to measure, 2) sampling design, 3) analytical framework, 4) temporal design, and 5) survey protocol. We also provide 2 hypothetical demonstrations of these study plan components representing different research questions and study systems. Mirroring the structure of hierarchical models, we suggest researchers primarily focus on the ecological processes of interest when designing their approach to sampling, and wait to consider logistical constraints of data collection and observation processes when developing the survey protocol. We offer a broad framework for researchers planning count‐based studies, while pointing to relevant literature elaborating on particular tools and concepts
The effect of timing and frequency of push notifications on usage of a smartphone-based stress management intervention: An exploratory trial
Push notifications offer a promising strategy for enhancing engagement with smartphone-based health interventions. Intelligent sensor-driven machine learning models may improve the timeliness of notifications by adapting delivery to a user's current context (e.g. location). This exploratory mixed-methods study examined the potential impact of timing and frequency on notification response and usage of Healthy Mind, a smartphone-based stress management intervention. 77 participants were randomised to use one of three versions of Healthy Mind that provided: intelligent notifications; daily notifications within pre-defined time frames; or occasional notifications within pre-defined time frames. Notification response and Healthy Mind usage were automatically recorded. Telephone interviews explored participants' experiences of using Healthy Mind. Participants in the intelligent and daily conditions viewed (d = .47, .44 respectively) and actioned (d = .50, .43 respectively) more notifications compared to the occasional group. Notification group had no meaningful effects on percentage of notifications viewed or usage of Healthy Mind. No meaningful differences were indicated between the intelligent and non-intelligent groups. Our findings suggest that frequent notifications may encourage greater exposure to intervention content without deterring engagement, but adaptive tailoring of notification timing does not always enhance their use. Hypotheses generated from this study require testing in future work. Trial registration number: ISRCTN67177737 © 2017 Morrison et al
Evidence of lensing of the cosmic microwave background by dark matter halos
We present evidence of the gravitational lensing of the cosmic microwave background by 1013 solar
mass dark matter halos. Lensing convergence maps from the Atacama Cosmology Telescope Polarimeter
(ACTPol) are stacked at the positions of around 12 000 optically selected CMASS galaxies from the
SDSS-III/BOSS survey. The mean lensing signal is consistent with simulated dark matter halo profiles and
is favored over a null signal at 3.2σ significance. This result demonstrates the potential of microwave
background lensing to probe the dark matter distribution in galaxy group and galaxy cluster halos
- …