1,130 research outputs found
Robust indoor speaker recognition in a network of audio and video sensors
AbstractSituational awareness is achieved naturally by the human senses of sight and hearing in combination. Automatic scene understanding aims at replicating this human ability using microphones and cameras in cooperation. In this paper, audio and video signals are fused and integrated at different levels of semantic abstractions. We detect and track a speaker who is relatively unconstrained, i.e., free to move indoors within an area larger than the comparable reported work, which is usually limited to round table meetings. The system is relatively simple: consisting of just 4 microphone pairs and a single camera. Results show that the overall multimodal tracker is more reliable than single modality systems, tolerating large occlusions and cross-talk. System evaluation is performed on both single and multi-modality tracking. The performance improvement given by the audioâvideo integration and fusion is quantified in terms of tracking precision and accuracy as well as speaker diarisation error rate and precisionârecall (recognition). Improvements vs. the closest works are evaluated: 56% sound source localisation computational cost over an audio only system, 8% speaker diarisation error rate over an audio only speaker recognition unit and 36% on the precisionârecall metric over an audioâvideo dominant speaker recognition method
The resting human brain and motor learning.
Functionally related brain networks are engaged even in the absence of an overt behavior. The role of this resting state activity, evident as low-frequency fluctuations of BOLD (see [1] for review, [2-4]) or electrical [5, 6] signals, is unclear. Two major proposals are that resting state activity supports introspective thought or supports responses to future events [7]. An alternative perspective is that the resting brain actively and selectively processes previous experiences [8]. Here we show that motor learning can modulate subsequent activity within resting networks. BOLD signal was recorded during rest periods before and after an 11 min visuomotor training session. Motor learning but not motor performance modulated a fronto-parietal resting state network (RSN). Along with the fronto-parietal network, a cerebellar network not previously reported as an RSN was also specifically altered by learning. Both of these networks are engaged during learning of similar visuomotor tasks [9-22]. Thus, we provide the first description of the modulation of specific RSNs by prior learning--but not by prior performance--revealing a novel connection between the neuroplastic mechanisms of learning and resting state activity. Our approach may provide a powerful tool for exploration of the systems involved in memory consolidation
A low-symmetry monothiatruxene-based hole transport material for planar nâiâp perovskite solar cells with 18.9% efficiency
Effect of an auxiliary acceptor on DâAâÏâA sensitizers for highly efficient and stable dye-sensitized solar cells
As one of the promising photovoltaic technologies, high performance metal-free dye-sensitized solar cells (DSSCs) have been explored due to the fact that they can be potentially produced using low-cost materials, their color can be tuned and they exhibit reasonable stability.</p
Star-shaped triarylamine-based hole-transport materials in perovskite solar cells
Two novel star-shaped triarylamine-based hole transport materials with triphenylamine (STR1), or a partially oxygen-bridged triphenylamine (STR0), as core and para-substituted triphenylamine side arms were synthesized, fully characterized and studied in perovskite solar cells. Their thermal, optical, electrochemical and charge transport properties were examined and compared in the context of their molecular structure. Due to its more planar configuration, STR0 showed a red-shifted absorption in comparison with STR1. STR0 also forms a more stable amorphous glassy state and showed higher glass transition temperature than STR1 and spiro-OMeTAD. These HTMs were tested in perovskite solar cells using a device configuration of FTO/bl-TiO2/mp-TiO2/CH3NH3PbI3/HTM/Au showing a power conversion efficiency of 13.3% for STR0 and 11.5% for STR1. The STR0-based devices showed higher fill factor and better reproducibility than spiro-OMeTAD-based cells. Without dopant additives, solar cells based on STR0 exhibited a good photocurrent density of 16.63 mA cmâ2 and the efficiency improved from a starting PCE of 3.9% to 6.6% after two weeks of storage
Plasma complement biomarkers distinguish multiple sclerosis and neuromyelitis optica spectrum disorder
Background: Multiple sclerosis (MS) and neuromyelitis optica spectrum disorders
(NMOSD) are autoimmune demyelinating diseases distinguished clinically by selective
involvement in NMOSD of optic nerves and spinal cord. Early clinical manifestations are
similar, complicating clinical management. Aquaporin-4 autoantibody measurement aids
diagnosis of NMOSD but is frequently negative, creating unmet need for alternative
biomarkers.
Objective: We investigated whether plasma complement proteins are altered in MS and
NMOSD and whether these provide biomarkers that reliably distinguish the diseases.
Methods: Plasma from 53 NMOSD, 49 MS and 69 control donors was tested in multiplex
assays measuring complement activation products and proteins. Logistic regression was used
to test whether combinations of complement analyte measurements distinguish NMOSD from
controls and MS.
Results: All activation products were significantly elevated in NMOSD compared to either
control or MS. Four complement proteins (C1inh, C1s, C5, FH) were significantly higher in
NMOSD compared to MS or controls. A model comprising C1 inhibitor and TCC
distinguished NMOSD from MS (area under curve (AUC) 0.98), while C1 inhibitor and C5
distinguished NMOSD from controls (AUC 0.94).
Conclusions: NMOSD is distinguished from MS by plasma complement activation
Establishment and operation of a Good Manufacturing Practice-compliant allogeneic Epstein-Barr virus (EBV)-specific cytotoxic cell bank for the treatment of EBV-associated lymphoproliferative disease
Funded by Wellcome Trust Translational Award SNBTSPeer reviewedPublisher PD
"You are just left to get on with it": qualitative study of patient and carer experiences of the transition to secondary progressive multiple sclerosis
Objectives Although the transition to secondary progressive multiple sclerosis (SPMS) is known to be a period of uncertainty for clinicians, who may find progressive disease challenging to objectively identify, little research has explored the experiences of patients and carers specifically during this transition period. Our objective was to explore what patients and their carers understand about their disease stage and describe their experiences and perspectives on the transition to SPMS.
Design Semistructured qualitative interviews and subsequent validation focus groups were analysed using inductive thematic analysis.
Setting South East Wales, UK.
Participants 20 patients with MS and 13 carers were interviewed. Eight patients and two carers participated in focus groups.
Results Four main themes around disease progression were identified. âRealisationâ describes how patients came to understand they had SPMS while âreactionâ describes their response to this realisation. The ârealitiesâ of living with SPMS, including dealing with the healthcare system during this period, were described along with âfuture challengesâ envisaged by patients and carers.
Conclusions Awareness that the transition to SPMS has occurred, and subsequent emotional reactions and coping strategies, varied widely between patients and their carers. The process of diagnosing the transition was often not transparent and some individuals wanted information to help them understand what the transition to SPMS meant for them
A join-based hybrid parameter for constraint satisfaction
We propose joinwidth, a new complexity parameter for the Constraint Satisfaction Problem (CSP). The definition of joinwidth is based on the arrangement of basic operations on relations (joins, projections, and pruning), which inherently reflects the steps required to solve the instance. We use joinwidth to obtain polynomial-time algorithms (if a corresponding decomposition is provided in the input) as well as fixed-parameter algorithms (if no such decomposition is provided) for solving the CSP.
Joinwidth is a hybrid parameter, as it takes both the graphical structure as well as the constraint relations that appear in the instance into account. It has, therefore, the potential to capture larger classes of tractable instances than purely structural parameters like hypertree width and the more general fractional hypertree width (fhtw). Indeed, we show that any class of instances of bounded fhtw also has bounded joinwidth, and that there exist classes of instances of bounded joinwidth and unbounded fhtw, so bounded joinwidth properly generalizes bounded fhtw. We further show that bounded joinwidth also properly generalizes several other known hybrid restrictions, such as fhtw with degree constraints and functional dependencies. In this sense, bounded joinwidth can be seen as a unifying principle that explains the tractability of several seemingly unrelated classes of CSP instances
- âŠ