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1.
iScience ; 26(5): 106751, 2023 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-37216100

RESUMO

Medium-and heavy-duty vehicles (MHDVs) comprise only a small fraction of vehicles on the road but disproportionately contribute to greenhouse gas emissions and air pollution from the transportation sector. Given the large variety of vehicle types-ranging from heavy-duty pickup trucks and box trucks to full-size buses and Class 8 tractor semi-trailers-and applications, multiple technologies offer opportunities to decarbonize MHDVs including battery-electric vehicles, hydrogen fuel cell vehicles, and sustainable liquid fuels. Here we provide an overview of the status, opportunities, challenges, and uncertainties for these competing-and potentially complementary-technologies, including consideration of supporting infrastructure and prospects for future success. We find a bright outlook for zero-emission vehicles and discuss remaining barriers and uncertainties around fleet decisions and changes to vehicle operation, infrastructure, manufacturing, and future fuel and technology trends that can be informed through analysis.

2.
Artigo em Inglês | MEDLINE | ID: mdl-23366331

RESUMO

Millimeter-wave technology shows high potential for future wireless personal area networks, reaching over 1 Gbps transmissions using simple modulation techniques. Current specifications consider dividing the spectrum into effortlessly separable spectrum ranges. These low requirements open a research area in time and space multiplexing techniques for millimeter-waves. In this work a process-stacking multiplexing access algorithm is designed for single channel operation. The concept is intuitive, but its implementation is not trivial. The key to stacking single channel events is to operate while simultaneously obtaining and handling a-posteriori time-frame information of scheduled events. This information is used to shift a global time pointer that the wireless access point manages and uses to synchronize all serviced nodes. The performance of the proposed multiplexing access technique is lower bounded by the performance of legacy TDMA and can significantly improve the effective throughput. Work is validated by simulation results.


Assuntos
Redes de Comunicação de Computadores/instrumentação , Monitorização Ambulatorial/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Telemetria/instrumentação , Fontes de Energia Elétrica , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Micro-Ondas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
3.
Artigo em Inglês | MEDLINE | ID: mdl-23366428

RESUMO

A novel experimental setup using accelerometer and gyroscope sensors embedded on a single board along with a distance-based pattern recognition algorithm is presented for accurately identifying basic movements for possible application in gaming using a mobile platform. As an example, we considered some basic step sequences in the popular dance game (e.g., dance dance revolution), and could detect these movements with a reasonably high probability. We envision that the experimental results presented in this paper will motivate future research in the world of mobile gaming applications using advanced smart phones with a dual module design.


Assuntos
Técnicas Biossensoriais/instrumentação , Movimento (Física) , Algoritmos , Humanos , Movimento/fisiologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-22254777

RESUMO

The wide scale deployment of wireless body area networks (WBANs) hinges on designing energy efficient communication protocols to support the reliable communication as well as to prolong the network lifetime. Cooperative communications, a relatively new idea in wireless communications, offers the benefits of multi-antenna systems, thereby improving the link reliability and boosting energy efficiency. In this short paper, the advantages of resorting to cooperative communications for WBANs in terms of minimized energy consumption are investigated. Adopting an energy model that encompasses energy consumptions in the transmitter and receiver circuits, and transmitting energy per bit, it is seen that cooperative transmission can improve energy efficiency of the wireless network. In particular, the problem of optimal power allocation is studied with the constraint of targeted outage probability. Two strategies of power allocation are considered: power allocation with and without posture state information. Using analysis and simulation-based results, two key points are demonstrated: (i) allocating power to the on-body sensors making use of the posture information can reduce the total energy consumption of the WBAN; and (ii) when the channel condition is good, it is better to recruit less relays for cooperation to enhance energy efficiency.


Assuntos
Redes de Comunicação de Computadores/instrumentação , Fontes de Energia Elétrica , Armazenamento e Recuperação da Informação/métodos , Monitorização Ambulatorial/instrumentação , Transdutores , Transferência de Energia , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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