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1.
Sensors (Basel) ; 18(12)2018 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-30486376

RESUMO

Collaboration between multiple Unmanned Aerial Vehicles (UAVs) to set up a Flying Ad Hoc Network (FANET) is a growing trend since future applications claim for more autonomous and rapid deployable systems. The user experience on watching videos transmitted over FANETs should always be satisfactory even under influence of topology changes caused by the energy consumption of UAVs. In addition, the FANET must keep the UAVs cooperating as much as possible during a mission. However, one of the main challenges in FANET is how to mitigate the impact of limited energy resources of UAVs on the FANET operation in order to monitor the environment for a long period of time. In this sense, UAV replacement is required in order to avoid the premature death of nodes, network disconnections, route failures, void areas, and low-quality video transmissions. In addition, decision-making must take into account energy consumption associated with UAV movements, since they are generally quite energy-intensive. This article proposes a cooperative UAV scheme for enhancing video transmission and global energy efficiency called VOEI. The main goal of VOEI is to maintain the video with QoE support while supporting the nodes with a good connectivity quality level and flying for a long period of time. Based on an Software Defined Network (SDN) paradigm, the VOEI assumes the existence of a centrailized controller node to compute reliable and energy-efficiency routes, as well as detects the appropriate moment for UAV replacement by considering global FANET context information to provide energy-efficiency operations. Based on simulation results, we conclude that VOEI can effectively mitigate the energy challenges of FANET, since it provides energy-efficiency operations, avoiding network death, route failure, and void area, as well as network partitioning compared to state-of-the-art algorithm. In addition, VOEI delivers videos with suitable Quality of Experience (QoE) to end-users at any time, which is not achieved by the state-of-the-art algorithm.

2.
Sensors (Basel) ; 18(2)2018 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-29364172

RESUMO

A wide range of multimedia services is expected to be offered for mobile users via various wireless access networks. Even the integration of Cloud Computing in such networks does not support an adequate Quality of Experience (QoE) in areas with high demands for multimedia contents. Fog computing has been conceptualized to facilitate the deployment of new services that cloud computing cannot provide, particularly those demanding QoE guarantees. These services are provided using fog nodes located at the network edge, which is capable of virtualizing their functions/applications. Service migration from the cloud to fog nodes can be actuated by request patterns and the timing issues. To the best of our knowledge, existing works on fog computing focus on architecture and fog node deployment issues. In this article, we describe the operational impacts and benefits associated with service migration from the cloud to multi-tier fog computing for video distribution with QoE support. Besides that, we perform the evaluation of such service migration of video services. Finally, we present potential research challenges and trends.

3.
J Pediatr Hematol Oncol ; 34(5): 326-35, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22627570

RESUMO

We examined the usability of smartphones for accessing a web-based e-Diary for self-monitoring symptoms in children and adolescents with sickle cell disease (SCD). One group of participants (n = 10; mean age, 13.1 ± 2.4 y; 5 M; 5 F) responded to questions using precompleted paper-based measures. A second group (n = 21; mean age, 13.4 ± 2.4 y; 10 M; 11 F) responded based on pain and symptoms they experienced over the previous 12 hours. The e-Diary was completed with at least 80% accuracy when compared to paper-based measures. Symptoms experienced over the previous 12 hours included feeling tired (33.3%), headache (28.6%), coughing (23.8%), lack of energy/fatigue (19.0%), yellowing of the eyes (19.0%), pallor (19.0%), irritability (19.0%), stiffness in joints (19.0%), general weakness (14.3%), and pain (14.3%), rating on average as 2.0 ± 1.7 (on 0 to 10 scale). Overall, sleep was good (8.1 ± 1.4 on the 0 to 10 scale). In conclusion, children with SCD were able to use smartphones to access a web-based e-Diary for reporting pain and symptoms. Smartphones may improve self-reporting of symptoms and communication between patients and their health care providers, who may consequently be able to improve pain and symptom management in children and adolescents with SCD in a timely manner.


Assuntos
Anemia Falciforme/terapia , Internet , Medição da Dor/métodos , Adolescente , Adulto , Anemia Falciforme/fisiopatologia , Telefone Celular , Criança , Feminino , Humanos , Masculino , Projetos Piloto , Adulto Jovem
4.
Comput Commun ; 35(2): 207-220, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22267882

RESUMO

Network lifetime and energy-efficiency are viewed as the dominating considerations in designing cluster-based communication protocols for wireless sensor networks. This paper analytically provides the optimal cluster size that minimizes the total energy expenditure in such networks, where all sensors communicate data through their elected cluster heads to the base station in a decentralized fashion. LEACH, LEACH-Coverage, and DBS comprise three cluster-based protocols investigated in this paper that do not require any centralized support from a certain node. The analytical outcomes are given in the form of closed-form expressions for various widely-used network configurations. Extensive simulations on different networks are used to confirm the expectations based on the analytical results. To obtain a thorough understanding of the results, cluster number variability problem is identified and inspected from the energy consumption point of view.

5.
Artigo em Inglês | MEDLINE | ID: mdl-19163301

RESUMO

We believe that each individual is unique, and that it is necessary for diagnosis purpose to have a distinctive combination of signals and data features that fits the personal health status. It is essential to develop mechanisms for reducing the amount of data that needs to be transferred (to mitigate the troublesome periodically recharging of a device) while maintaining diagnostic accuracy. Thus, the system should not uniformly compress the collected physiological data, but compress data in a personalized fashion that preserves the 'important' signal features for each individual such that it is enough to make the diagnosis with a required high confidence level. We present a diagnostic quality driven mechanism for remote ECG monitoring, which enables a notation of priorities encoded into the wave segments. The priority is specified by the diagnosis engine or medical experts and is dynamic and individual dependent. The system pre-processes the collected physiological information according to the assigned priority before delivering to the backend server. We demonstrate that the proposed approach provides accurate inference results while effectively compressing the data.


Assuntos
Técnicas Biossensoriais/instrumentação , Redes de Comunicação de Computadores/instrumentação , Diagnóstico por Computador/instrumentação , Eletrocardiografia/métodos , Monitorização Ambulatorial/instrumentação , Telemedicina/instrumentação , Algoritmos , Tecnologia Biomédica/instrumentação , Redes de Comunicação de Computadores/organização & administração , Computadores , Computadores de Mão , Diagnóstico por Computador/métodos , Humanos , Monitorização Fisiológica/instrumentação , Reprodutibilidade dos Testes , Processamento de Sinais Assistido por Computador , Interface Usuário-Computador
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