910 research outputs found
Block-sparse approach for the identification of complex sound sources in a room
International audienceGeometrical acoustic softwares are necessary to produce auralizations for specific sound environment. Whether the room impulse response computation require point-source and receiver to be of omnidirectional sensitivity, the influence of their directivity on the resulting virtual audio rendering Is relevant. It is then crucial to account for when simulating accurately a calibrate acoustic model.We treats here the case of the source directivity. The use of a spherical surrounding microphone array remains the most natural way to measure it. The source is located inside the delimiting volume. The radiated pressure is sampled at fixed points. The directivity pattern is then computed in term of spherical harmonics functions. But due to hardware complexity, most of the spherical antennas in the litterature have a few number of microphones. This limits the performance of the antenna in term of resolution and bandwidth. Also, decomposition errors can appear with a possible mismatch between the acoustic center of the source and the origin of the array. An additional optimization task is required which increases the complexity of the process.In this paper, we propose a practical strategy, comprising a dedicated algorithm and an array design, to estimate the directivity pattern of complex sound sources. The study takes place in reverberant rooms.Firstly, we describe a greedy-sparse algorithm called Block Orthogonal Matching Pursuit. By this iterative approach, the identification and characterization tasks can be joint in a unique scheme. This facilitates the acoustic center research. However, under non-anechoic conditions, BlockOMP fails because of the free-field propagation assumption. Considering the first reflections to approximate the room transfer function permits to solve the inverse problem. The notion of virtual microphone arrays, based on an analogy with the Image Source Method, is introduced to extend the validity of BlockOMP. Numerical results supply a proof of the concept in a scenario including multiple acoustic sources.Secondly, a large three-dimensional microphone array is deployed. Largeness concerns here in both its dimensions and the number of microphones. The array consists of five sub-planes which surround the entire room where sources are located. The acquisition system comprises digital MEMS microphones chips. The entire signal processing chain is directly integrated on the captor. The microphones are flush mounted on the walls of the room. The true location of the sensors is known, given by an acoustic geometrical calibration step. The 1024 MEMS record synchronously the pressure signal emitted by the sources. From each harmonic spectral component, a sparse spherical harmonics decomposition of each target can be achieved.An experiment is performed to assert the efficiency of the proposed strategy. The goal is to recover the nature of two prototypes of source. They are build from an unbaffled loudspeaker, arranged to show a dipole and a quadripole behaviour. Their directivity pattern are previously measured under controlled conditions using a semi-circular array of 64 microphones. This database serves here as reference. For the experiment, they emit the same signal simultaneous. The results with our system indicates good correlations. Separating both the sound radiating contribution is well achieved. Our last study case deals with the voice directivity measurements. If the dependence with the frequency has been established, the effect of the phonema variation is rarely identified. We demonstrate here that our apparatus constitutes a powerful tool to examine this aspect
Relative multiplexing for minimizing switching in linear-optical quantum computing
Many existing schemes for linear-optical quantum computing (LOQC) depend on
multiplexing (MUX), which uses dynamic routing to enable near-deterministic
gates and sources to be constructed using heralded, probabilistic primitives.
MUXing accounts for the overwhelming majority of active switching demands in
current LOQC architectures. In this manuscript, we introduce relative
multiplexing (RMUX), a general-purpose optimization which can dramatically
reduce the active switching requirements for MUX in LOQC, and thereby reduce
hardware complexity and energy consumption, as well as relaxing demands on
performance for various photonic components. We discuss the application of RMUX
to the generation of entangled states from probabilistic single-photon sources,
and argue that an order of magnitude improvement in the rate of generation of
Bell states can be achieved. In addition, we apply RMUX to the proposal for
percolation of a 3D cluster state in [PRL 115, 020502 (2015)], and we find that
RMUX allows a 2.4x increase in loss tolerance for this architecture.Comment: Published version, New Journal of Physics, Volume 19, June 201
Towards an Understanding, Through Action Research,of the Socio-Organizational Issues Impacting on MobileTechnology Adoption and Diffusion Within a Small-to-Medium South African Construction Company
We investigated, through an action research approach, social issues that impact
on mobile technology adoption and diffusion in a professional construction management
team of a small-to-medium sized South African construction company. The outcome of the
study resulted in a framework of thinking that integrates social factors at individual and
organisational levels that impacted on the adoption of mobile technologies in the organisation.
At the methodological level the study is part of a limited collection of papers that
used AR in the study of technology adoption and diffusion and it presents an example of
the capability of AR as a method to allow for the integration of the social contexts of users
into adoption frameworks.College of Engineering, Science and Technolog
Function Allocation for Humans and Automation in the Context of Team Dynamics
AbstractWithin Human Factors Engineering, a decision-making process called function allocation (FA) is used during the design life cycle of complex systems to distribute the system functions, typically identified through a functional requirements analysis, to all human and automated machine agents (or teammates) involved in controlling the system. Most FA methods make allocation decisions primarily by comparing the capabilities of humans and automation, and then by considering secondary factors such as cost, regulations, and the health and safety of workers. The primary analysis of the strengths and weaknesses of humans and machines, however, is almost always considered in terms of individual human or machine capabilities. Yet, FA is fundamentally about teamwork in that the goal of the FA decision-making process is to determine the optimal allocations of functions among agents. Given this framing of FA, and the increasing use of and sophistication of automation, there are two related social psychological issues that current FA methods need to address more thoroughly. First, many principles for effective human teamwork are not considered as central decision points or in the iterative hypothesis and testing phase in most FA methods, despite the fact that social factors have numerous positive and negative effects on individual and team capabilities. Second, social psychological factors affecting team performance can be difficult to translate to automated agents, and most FA methods currently do not account for this effect. The implications for these issues are discussed
Notificação de COVID-19 relacionada ao trabalho: estudo descritivo sobre o perfil sociodemográfico e ocupacional, Brasil, 2020
TCC(graduação) - Universidade Federal de Santa Catarina. Centro de Ciências da Saúde. Medicina.Objetivo: realizar uma análise descritiva dos casos notificados de COVID-19 relacionados ao trabalho no Brasil, em 2020.
Método: estudo descritivo com dados coletados do Sistema de Informação de Agravos de Notificação (SINAN). As variáveis do estudo foram sexo, raça, escolaridade, região do Brasil, faixa etária, Comunicação de Acidente no Trabalho (CAT), evolução e ocupação. Os dados foram organizados e analisados utilizando o software Stata® 14.0.
Resultados: foram notificados 30.802 casos, com predominância de mulheres (67,3%) e pessoas negras (48%). Os trabalhadores/profissionais da saúde foram o grupo ocupacional mais afetado (57,5%), porém também foram analisadas outras ocupações não relacionadas a saúde. Observou-se alta frequência de casos em que não houve preenchimento das variáveis raça (16,1%) e escolaridade (27,3%). Além disso, notou-se que apenas 16,1% dos trabalhadores tiveram sua CAT emitida.
Discussão: os resultados sugerem disparidades sociodemográficas e ocupacionais nas infecções pelo COVID-19, reforçando uma maior necessidade de atenção por parte dos órgãos governamentais para políticas públicas que garantem maior proteção à saúde dos trabalhadores. Além de destacar uma baixa qualidade no preenchimento das notificações de casos de COVID-19 relacionados ao trabalho.Objective: to perform a descriptive analysis of reported work-related COVID-19 cases in Brazil in 2020.
Methods: Descriptive study with data collected from the Information System for Notifiable Diseases (SINAN). The study variables were sex, race, education, region of Brazil, age group, Occupational Accident Communication (CAT), evolution and occupation. Data were organized and analyzed using the Stata® 14.0 software.
Results: 30,802 cases were reported, with a predominance of women (67.3%) and black people (48%). Health workers/professionals were the most affected occupational group (57.5%), but other non-health-related occupations were also analyzed. The study also highlighted a high frequency of cases in which the variables race (16.1%) and education (27.3%) were not filled out. In addition, it was noted that only 16,1% of workers had their CAT issued.
Discussion: The results suggest sociodemographic and occupational disparities in COVID-19 infections, reinforcing a greater need for attention by government agencies for public policies that guarantee greater protection to worker’s health. In addition to highlighting the low quality of filling in notifications of work-related COVID-19 in Brazil
Temporal effects of antibiotic use and hand rub consumption on the incidence of MRSA and Clostridium difficile
Objectives The aim of this study was to determine the temporal relation between the use of antibiotics and alcohol-based hand rubs (ABHRs) and the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile. Methods An interventional time-series analysis was performed to evaluate the impact of two promotion campaigns on the consumption of ABHRs and to assess their effect on the incidence of non-duplicate clinical isolates of MRSA and C. difficile from February 2000 through September 2006. This analysis was combined with a transfer function model of aggregated data on antibiotic use. Results Consumption of ABHRs correlated with MRSA, but not with C. difficile. The final model demonstrated the immediate effect of the second hand hygiene promotion campaign and an additional temporal effect of fluoroquinolone (time lag, 1 month; i.e. antibiotic effect delayed for 1 month), macrolide (lag 1 and 4 months), broad-spectrum cephalosporins (lag 3, 4 and 5 months) and piperacillin/tazobactam (lag 3 months) use. The final model explained 57% of the MRSA variance over time. In contrast, the model for C. difficile showed only an effect for broad-spectrum cephalosporins (lag 1 month). Conclusions We observed an aggregate-level relation between the monthly MRSA incidence and the use of different antibiotic classes and increased consumption of ABHR after a successful hand hygiene campaign, while no association with ABHR use was detected for C. difficil
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A Multi-Methods Approach to HRA and Human Performance Modeling: A Field Assessment
The Advanced Test Reactor (ATR) is a research reactor at the Idaho National Laboratory is primarily designed and used to test materials to be used in other, larger-scale and prototype reactors. The reactor offers various specialized systems and allows certain experiments to be run at their own temperature and pressure. The ATR Canal temporarily stores completed experiments and used fuel. It also has facilities to conduct underwater operations such as experiment examination or removal. In reviewing the ATR safety basis, a number of concerns were identified involving the ATR canal. A brief study identified ergonomic issues involving the manual handling of fuel elements in the canal that may increase the probability of human error and possible unwanted acute physical outcomes to the operator. In response to this concern, that refined the previous HRA scoping analysis by determining the probability of the inadvertent exposure of a fuel element to the air during fuel movement and inspection was conducted. The HRA analysis employed the SPAR-H method and was supplemented by information gained from a detailed analysis of the fuel inspection and transfer tasks. This latter analysis included ergonomics, work cycles, task duration, and workload imposed by tool and workplace characteristics, personal protective clothing, and operational practices that have the potential to increase physical and mental workload. Part of this analysis consisted of NASA-TLX analyses, combined with operational sequence analysis, computational human performance analysis (CHPA), and 3D graphical modeling to determine task failures and precursors to such failures that have safety implications. Experience in applying multiple analysis techniques in support of HRA methods is discussed
HFE Process Guidance and Standards for potential application to updating NRC guidance
The U.S. Nuclear Regulatory Commission (NRC) reviews and evaluates the human factors engineering (HFE) programs of applicants for nuclear power plant construction permits, operating licenses, standard design certifications, and combined operating licenses. The purpose of these safety reviews is to help ensure that personnel performance and reliability are appropriately supported. Detailed design review procedures and guidance for the evaluations is provided in three key documents: the Standard Review Plan (NUREG-0800), the HFE Program Review Model (NUREG-0711), and the Human-System Interface Design Review Guidelines (NUREG-0700). These documents were last revised in 2007, 2004 and 2002, respectively. The NRC is committed to the periodic update and improvement of these guidance documents to ensure that they remain state-of-the-art design evaluation tools. Thus, the NRC has initiated a project with BNL to update the NRC guidance to remain current with recent research on human performance, advances in HFE methods and tools, and new technology. INL supported Brookhaven National Lab (BNL) to update the detailed HFE review criteria contained in NUREG-0711 and NUREG-0700 based on (1) feedback obtained from end users, (2) the results of NRC research and development efforts supporting the NRC staff’s HFE safety reviews, and (3) other material the project staff identify as applicable to the update effort. INL submitted comments on development plans and sections of NUREGs 0800, 0711, and 0700. The contractor prepared the report attached here as the deliverable for this work
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