1,026 research outputs found
Investigating Coordination Indicators in Epidemiological Surveillance for Influenza
Containing infectious disease requires coordination among various epidemiology organizations on a global basis. Coordination at a global level is dependent epidemiological surveillance processes that, while under the management of local epidemiology departments, require the participation of a disparate group of non-epidemiologists. In this paper, the influenza virus is isolated to examine if strong analytic process coordination is occurring in practice for this annually reoccurring disease. Confirmatory factor analysis is utilized on 2,484 cases of influenza recorded during a 15-month timeframe in the epidemiological database of a local public health department. The results confirm the presence of four, primary constructs that underlie this analytical process. The results suggest that coordination conflict is substantial even with a cyclically, reoccurring disease. The analysis demonstrates how theory and methodology can intertwine to assist in identifying process coordination and conflict in epidemiological surveillance, and support the application of this analysis approach to other analytical processes
Assessing Value in Organizational Knowledge Creation: Considerations for Knowledge Workers
This is the published version. Copyright 2005 MIS Quarterly.To maintain competitive advantage, a firm's investment decisions related to knowledge creation are likely to be strategic in nature. However, strategic investments usually have an element of risk linked to uncertain and deferred investment benefits. To date, such investment decisions relating to knowledge workers have not been extensively researched. In this paper, we explore the following research question: How do we strategically assess knowledge creation over time giving consideration to complex decision criteria in order to improve organizational value? We develop a model based on economic and organization theory for assessing organizational value with regard to knowledge creation investments. Our model prototype provides managers with a learning tool relating to the timing and selection of knowledge creation investments. Our own use of the tool in simulation experiments yielded several insights which suggest that the decisions typically made by managers may dilute knowledge creation investments. Our results demonstrate that the organizational benefit of knowledge creation processes should be well aligned with near-term tasks. Under instances of high knowledge depreciation, however, it is unlikely that individual workers can optimize knowledge creation process decisions without organizational involvement in matching skills to task complexities. The organizational benefits of consistent and frequent knowledge creation process participation increase over time as the match of skills and task complexities improve
Using design experiments to conduct research on mathematics professional development
In this paper, we propose that the emerging transformation of mathematics professional development from a practice-based to a research field would benefit from stronger connections to research on learning. In particular, we contend that design experiments represent a premier emerging methodology to study learning, and we argue that a better understanding of teacher learning through the use of design experiments in mathematics professional development can lead to improvement of mathematics professional development as both an area of practice and a field of research
Towards automating underwater measurement of fish length: a comparison of semi-automatic and manual stereo–video measurements
Underwater stereo–video systems are widely used for counting and measuring fish in aquaculture, fisheries, and conservation management. Length measurements are generated from stereo–video recordings by a software operator using a mouse to locate the head and tail of a fish in synchronized pairs of images. This data can be used to compare spatial and temporal changes in the mean length and biomass or frequency distributions of populations of fishes. Since the early 1990s stereo–video has also been used for measuring the lengths of fish in aquaculture for quota and farm management. However, the costs of the equipment, software, the time, and salary costs involved in post processing imagery manually and the subsequent delays in the availability of length information inhibit the adoption of this technology. We present a semi-automatic method for capturing stereo–video measurements to estimate the lengths of fish. We compare the time taken to make measurements of the same fish measured manually from stereo–video imagery to that measured semi-automatically. Using imagery recorded during transfers of Southern Bluefin Tuna (SBT) from tow cages to grow out cages, we demonstrate that the semi-automatic algorithm developed can obtain fork length measurements with an error of less than 1% of the true length and with at least a sixfold reduction in operator time in comparison to manual measurements. Of the 22 138 SBT recorded we were able to measure 52.6% (11 647) manually and 11.8% (2614) semi-automatically. For seven of the eight cage transfers recorde,d there were no statistical differences in the mean length, weight, or length frequency between manual and semi-automatic measurements. When the data were pooled across the eight cage transfers, there was no statistical difference in mean length or weight between the stereo–video-based manual and semi-automated measurements. Hence, the presented semi-automatic system can be deployed to significantly reduce the cost involved in adoption of stereo–video technology
Hybrid Group IV Nanophotonic Structures Incorporating Diamond Silicon-Vacancy Color Centers
We demonstrate a new approach for engineering group IV semiconductor-based
quantum photonic structures containing negatively charged silicon-vacancy
(SiV) color centers in diamond as quantum emitters. Hybrid SiC/diamond
structures are realized by combining the growth of nanoand micro-diamonds on
silicon carbide (3C or 4H polytype) substrates, with the subsequent use of
these diamond crystals as a hard mask for pattern transfer. SiV color
centers are incorporated in diamond during its synthesis from molecular diamond
seeds (diamondoids), with no need for ionimplantation or annealing. We show
that the same growth technique can be used to grow a diamond layer controllably
doped with SiV on top of a high purity bulk diamond, in which we
subsequently fabricate nanopillar arrays containing high quality SiV
centers. Scanning confocal photoluminescence measurements reveal optically
active SiV lines both at room temperature and low temperature (5 K) from
all fabricated structures, and, in particular, very narrow linewidths and small
inhomogeneous broadening of SiV lines from all-diamond nano-pillar arrays,
which is a critical requirement for quantum computation. At low temperatures (5
K) we observe in these structures the signature typical of SiV centers in
bulk diamond, consistent with a double lambda. These results indicate that high
quality color centers can be incorporated into nanophotonic structures
synthetically with properties equivalent to those in bulk diamond, thereby
opening opportunities for applications in classical and quantum information
processing
Abundances of ammonia and carbon disulfide in the Jovian stratosphere following the impact of comet Shoemaker‐Levy 9
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95648/1/grl8459.pd
Numerical and experimental evaluation of shock dividers
Mitigation of pressure pulsations in the exhaust of a pulse detonation combustor is crucial for operation with a downstream turbine. For this purpose, a device termed the shock divider is designed and investigated. The intention of the divider is to split the leading shock wave into two weaker waves that propagate along separated ducts with different cross sections, allowing the shock waves to travel with different velocities along different paths. The separated shock waves redistribute the energy of the incident shock wave. The shock dynamics inside the divider are investigated using numerical simulations. A second-order dimensional split finite volume MUSCL-scheme is used to solve the compressible Euler equations. Furthermore, low-cost simulations are performed using geometrical shock dynamics to predict the shock wave propagation inside the divider. The numerical simulations are compared to high-speed schlieren images and time-resolved total pressure recording. For the latter, a high-frequency pressure probe is placed at the divider outlet, which is shown to resolve the transient total pressure during the shock passage. Moreover, the separation of the shock waves is investigated and found to grow as the divider duct width ratio increases. The numerical and experimental results allow for a better understanding of the dynamic evolution of the flow inside the divider and inform its capability to reduce the pressure pulsations at the exhaust of the pulse detonation combustor
Improved limits on nuebar emission from mu+ decay
We investigated mu+ decays at rest produced at the ISIS beam stop target.
Lepton flavor (LF) conservation has been tested by searching for \nueb via the
detection reaction p(\nueb,e+)n. No \nueb signal from LF violating mu+ decays
was identified. We extract upper limits of the branching ratio for the LF
violating decay mu+ -> e+ \nueb \nu compared to the Standard Model (SM) mu+ ->
e+ nue numub decay: BR < 0.9(1.7)x10^{-3} (90%CL) depending on the spectral
distribution of \nueb characterized by the Michel parameter rho=0.75 (0.0).
These results improve earlier limits by one order of magnitude and restrict
extensions of the SM in which \nueb emission from mu+ decay is allowed with
considerable strength. The decay \mupdeb as source for the \nueb signal
observed in the LSND experiment can be excluded.Comment: 10 pages, including 1 figure, 1 tabl
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