146 research outputs found
Fundamental noise limitations to supercontinuum generation in microstructure fiber
Broadband noise on supercontinuum spectra generated in microstructure fiber
is shown to lead to amplitude fluctuations as large as 50 % for certain input
laser pulse parameters. We study this noise using both experimental
measurements and numerical simulations with a generalized stochastic nonlinear
Schroedinger equation, finding good quantitative agreement over a range of
input pulse energies and chirp values. This noise is shown to arise from
nonlinear amplification of two quantum noise inputs: the input pulse shot noise
and the spontaneous Raman scattering down the fiber.Comment: 16 pages with 6 figure
E-profiles, Conflict, and Shared Understanding in Distributed Teams
In this research, we examine the efficacy of a technological intervention in shaping distributed team members’ perceptions about their teammates. We argue that, by exposing distributed team members to electronic profiles (e-profiles) with information emphasizing their personal similarities with one another, distributed teams should experience lower levels of relational and task conflict. In turn, reductions in conflict should facilitate a shared understanding among team members, which should increase their team effectiveness. The results of a laboratory experiment of 46 distributed teams generally support these assertions. Specifically, we found that a simple, technological intervention can reduce task conflict in distributed teams, which, in turn, improves shared understanding and team effectiveness. We also uncovered important differences in the antecedents and impacts of relational and task conflict. Although we found that the e-profile intervention was effective in accounting for variance in task conflict (R2 = .41), it was quite poor in accounting for variance in relational conflict (R2 = .04). The model accounts for 33% and 43% of the variance in shared understanding and team effectiveness, respectively. Taken together, the results of this research suggest that the information shared about team members in distributed team settings has important implications for their ability to collaborate, achieve a common understanding of their work, and accomplish their task effectively. We suggest that e-profiles may be a useful intervention for management to enhance effectiveness in distributed teams
Optical microbubble resonator
We develop a method for fabricating very small silica microbubbles having a micrometer-order wall thickness and demonstrate the first optical microbubble resonator. Our method is based on blowing a microbubble using stable radiative CO2 laser heating rather than unstable convective heating in a flame or furnace. Microbubbles are created along a microcapillary and are naturally opened to the input and output microfluidic or gas channels. The demonstrated microbubble resonator has 370 µm diameter, 2 µm wall thickness, and a Q factor exceeding 10
Super FSR tunable optical microbubble resonator
An optical resonator is often called fully tunable if its tunable range
exceeds the spectral interval that contains the resonances at all the
characteristic modes of this resonator. For the high Q-factor spheroidal and
toroidal microresonators, this interval coincides with the azimuthal free
spectral range. In this Letter, we demonstrate the first mechanically fully
tunable spheroidal microresonator created of a silica microbubble having a 100
micron order radius and a micron order wall thickness. The tunable bandwidth of
this resonator is more than two times greater than its azimuthal free spectral
range
Prognostic markers in cancer: the evolution of evidence from single studies to meta-analysis, and beyond
In oncology, prognostic markers are clinical measures used to help elicit an individual patient's risk of a future outcome, such as recurrence of disease after primary treatment. They thus facilitate individual treatment choice and aid in patient counselling. Evidence-based results regarding prognostic markers are therefore very important to both clinicians and their patients. However, there is increasing awareness that prognostic marker studies have been neglected in the drive to improve medical research. Large protocol-driven, prospective studies are the ideal, with appropriate statistical analysis and clear, unbiased reporting of the methods used and the results obtained. Unfortunately, published prognostic studies rarely meet such standards, and systematic reviews and meta-analyses are often only able to draw attention to the paucity of good-quality evidence. We discuss how better-quality prognostic marker evidence can evolve over time from initial exploratory studies, to large protocol-driven primary studies, and then to meta-analysis or even beyond, to large prospectively planned pooled analyses and to the initiation of tumour banks. We highlight articles that facilitate each stage of this process, and that promote current guidelines aimed at improving the design, analysis, and reporting of prognostic marker research. We also outline why collaborative, multi-centre, and multi-disciplinary teams should be an essential part of future studies
Optical Environmental Sensing in Wireless Smart Meter Network
In recent years, the traditional power grid is undergoing a profound revolution due to the advent and development of smart grid. Many hard and challenging issues of the traditional grid such as high maintenance costs, poor scalability, low efficiency, and stability can be effectively handled and solve in the wireless smart grid (WSG) by utilizing the modern wireless sensor technology. In a WSG, data are collected by sensors at first and then transmitted to the base station through the wireless network. The control centre is responsible for taking actions based on this received data. Traditional sensors are failing to provide accurate and reliable data in WSG, and optical fiber based sensor are emerging as an obvious choice due to the advancement of optical fiber sensing technology, accuracy, and reliability. This paper presents a WSG platform integrated with optic fiber-based sensors for real-time monitoring. To demonstrate the validity of the concept, fresh water sensing of refractive index (RI) was first experimented with an optical fiber sensor. The sensing mechanism functions with the reflectance at the fiber’s interface where reflected spectra’s intensity is registered corresponding to the change of RI in the ambient environment. The achieved sensitivity of the fabricated fiber sensor is 29.3 dB/RIU within the 1.33–1.46 RI range. An interface between the measured optical spectra and the WSG is proposed and demonstrated, and the data acquired is transmitted through a network of wireless smart meters
Crowdsourcing Coordination: A Review and Research Agenda for Crowdsourcing Coordination Used for Macro-tasks
Crowdsourcing has become a widely accepted approach to leveraging the skills and expertise of others to accomplish work. Despite the potential of crowdsourcing to tackle complex problems, it has often been used to address simple micro-tasks. To tackle more complex macro-tasks, more attention is needed to better comprehend crowd coordination. Crowd coordination is defined as the synchronization of crowd workers in an attempt to direct and align their efforts in pursuit of a shared goal. The goal of this chapter is to advance our understanding of crowd coordination to tackle complex macro-tasks. To accomplish this, we have three objectives. First, we review popular theories of coordination. Second, we examine the current approaches to crowd coordination in the HCI and CSCW literature. Finally, the chapter identifies shortcomings in the literature and proposes a research agenda directed at advancing our understanding of crowd coordination needed to address complex macro-tasks.National Science Foundation grant CHS-1617820Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150620/1/Kim and Robert 2019 Preprint Chapter 2.pdfDescription of Kim and Robert 2019 Preprint Chapter 2.pdf : Preprint Versio
Crowdsourcing Controls: A Review and Research Agenda for Crowdsourcing Controls Used for Macro-tasks
Crowdsourcing—the employment of ad hoc online labor to perform various tasks—has become a popular outsourcing vehicle. Our current approach to crowdsourcing—focusing on micro-tasks—fails to leverage the potential of crowds to tackle more complex problems. To leverage crowds to tackle more complex macro tasks requires a better comprehension of crowdsourcing controls. Crowdsourcing controls are mechanisms used to align crowd workers’ actions with predefined standards to achieve a set of goals and objectives. Unfortunately, we know very little about the topic of crowdsourcing controls directed at accomplishing complex macro tasks. To address issues associated with crowdsourcing controls formacro-tasks, this chapter has several objectives. First, it presents and discusses the literature on control theory. Second, this chapter presents a scoping literature review of crowdsourcing controls. Finally, the chapter identifies gaps and puts forth a research agenda to address these shortcomings. The research agenda focuses on understanding how to employ the controls needed to perform macro-tasking in crowds and the implications for crowdsourcing system designers.National Science Foundation grant CHS-1617820Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150493/1/Robert 2019 Preprint Chapter 3.pdfDescription of Robert 2019 Preprint Chapter 3.pdf : PrePrint Versio
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