289 research outputs found
Autonomous Robotic System using Non-Destructive Evaluation methods for Bridge Deck Inspection
Bridge condition assessment is important to maintain the quality of highway
roads for public transport. Bridge deterioration with time is inevitable due to
aging material, environmental wear and in some cases, inadequate maintenance.
Non-destructive evaluation (NDE) methods are preferred for condition assessment
for bridges, concrete buildings, and other civil structures. Some examples of
NDE methods are ground penetrating radar (GPR), acoustic emission, and
electrical resistivity (ER). NDE methods provide the ability to inspect a
structure without causing any damage to the structure in the process. In
addition, NDE methods typically cost less than other methods, since they do not
require inspection sites to be evacuated prior to inspection, which greatly
reduces the cost of safety related issues during the inspection process. In
this paper, an autonomous robotic system equipped with three different NDE
sensors is presented. The system employs GPR, ER, and a camera for data
collection. The system is capable of performing real-time, cost-effective
bridge deck inspection, and is comprised of a mechanical robot design and
machine learning and pattern recognition methods for automated steel rebar
picking to provide realtime condition maps of the corrosive deck environments
Tunable light-matter interaction and the role of hyperbolicity in graphene-hBN system
Hexagonal boron nitride (hBN) is a natural hyperbolic material which can also
accommodate highly dispersive surface phonon-polariton modes. In this paper, we
examine theoretically the mid-infrared optical properties of graphene-hBN
heterostructures derived from their coupled plasmon-phonon modes. We found that
the graphene plasmon couples differently with the phonons of the two
Reststrahlen bands, owing to their different hyperbolicity. This also leads to
distinctively different interaction between an external quantum emitter and the
plasmon-phonon modes in the two bands, leading to substantial modification of
its spectrum. The coupling to graphene plasmons allows for additional gate
tunability in the Purcell factor, and narrow dips in its emission spectra
Mirror symmetry and the Breuil-M\'ezard Conjecture
The Breuil-M\'{e}zard Conjecture predicts the existence of hypothetical
"Breuil-Mezard cycles" in the moduli space of mod Galois representations of
that should govern
congruences between mod automorphic forms. For generic parameters, we
propose a construction of Breuil-M\'{e}zard cycles in arbitrary rank, and
verify that they satisfy the Breuil-M\'{e}zard Conjecture for all sufficiently
generic tame types and small Hodge-Tate weights. Our method is purely local and
group-theoretic, and completely distinct from previous approaches to the
Breuil-M\'ezard Conjecture. In particular, we leverage new connections between
the Breuil-M\'ezard Conjecture and phenomena occurring in homological mirror
symmetry and geometric representation theory.Comment: minor correction
Chiral plasmon in gapped Dirac systems
We study the electromagnetic response and surface electromagnetic modes in a
generic gapped Dirac material under pumping with circularly polarized light.
The valley imbalance due to pumping leads to a net Berry curvature, giving rise
to a finite transverse conductivity. We discuss the appearance of nonreciprocal
chiral edge modes, their hybridization and waveguiding in a nanoribbon
geometry, and giant polarization rotation in nanoribbon arrays
Necrotizing Fasciitis Associated with Staphylococcus lugdunensis
Necrotizing fasciitis is a life-threatening soft tissue infection that results in rapid local tissue destruction. Type 1 necrotizing fasciitis is characterized by polymicrobial, synergistic infections that are caused by non-Group A streptococci, aerobic and anaerobic organisms. Type 2 necrotizing fasciitis involves Group A Streptococcus (GAS) with or without a coexisting staphylococcal infection. Here we provide the first report of necrotizing fasciitis jointly associated with the microbes Group B Streptococcus and Staphylococcus lugdunensis. S. lugdunensis is a commensal human skin bacterium known to cause often painful and prolonged skin and soft tissue infections. To our knowledge, however, this is the first case of Staph. lugdunensis-associated necrotizing fasciitis to be reported in the literature
Tunable Light–Matter Interaction and the Role of Hyperbolicity in Graphene–hBN System
Hexagonal boron nitride (hBN) is a natural hyperbolic material, which can also accommodate highly dispersive surface phonon-polariton modes. In this paper, we examine theoretically the mid-infrared optical properties of graphene–hBN heterostructures derived from their coupled plasmon–phonon modes. We find that the graphene plasmon couples differently with the phonons of the two Reststrahlen bands, owing to their different hyperbolicity. This also leads to distinctively different interaction between an external quantum emitter and the plasmon–phonon modes in the two bands, leading to substantial modification of its spectrum. The coupling to graphene plasmons allows for additional gate tunability in the Purcell factor and narrow dips in its emission spectra.National Science Foundation (U.S.) (CMMI-1120724)United States. Office of Naval Research. Multidisciplinary University Research Initiative (FA9550-12-1-0488
Justice in inter-organizational relationships: A literature review and future research agenda
Organizational justice has made contributions to the inter-organizational literature by highlighting the effects of justice perceptions on behavioral, attitudinal, and organizational outcomes. However, research on justice perceptions remains scattered and falls short of addressing key elements of justice, and how these elements interact in an inter-organizational context. The lack of understanding calls for a comprehensive review and synthesis of extant studies. After a careful initial review of 375 papers from 1995 to 2018, this paper consolidates 79 papers on organizational justice at an inter-organizational level with respect to theoretical perspectives, methodologies, contexts, and research findings. The thematic and descriptive analyses offer deeper insights into the varying effects of different organizational justice dimensions, and bring forward limitations of current research including a focus on a: single side of the dyad, static view of justice, and single level of analysis. Consequently, the synthesis section, derived from the thematic analysis, draws out three fruitful key themes including: i) justice asymmetry; ii) justice dynamics; and iii) multilevel view of justice. The study positions fruitful research questions for each theme, before presenting the study's limitations and implications
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