Energy Efficient Resource Allocation for Demand Intensive Applications in a VLC Based Fog Architecture

In this paper, we propose an energy efficient passive optical network (PON) architecture for backhaul connectivity in indoor visible light communication (VLC) systems. The proposed network is used to support a fog computing architecture designed to allow users with processing demands to access dedicated fog nodes and idle processing resources in other user devices (UDs) within the same building. The fog resources within a building complement fog nodes at the access and metro networks and the central cloud data center. A mixed integer linear programming (MILP) model is developed to minimize the total power consumption associated with serving demands over the proposed architecture. A scenario that considers applications with intensive demands is examined to evaluate the energy efficiency of the proposed architecture. A comparison is conducted between allocating the demands in the fog nodes and serving the demands in the conventional cloud data center. Additionally, the proposed architecture is compared with an architecture based on state-of-art Spine-and-Leaf (SL) connectivity. Relative to the SL architecture and serving all the demands in the cloud, the adoption of the PON-based architecture achieves 84% and 86% reductions, respectively.Comment: arXiv admin note: substantial text overlap with arXiv:2203.1138

A comparative study of the complications of surgical tracheostomy in morbidly obese critically ill patients. Crit Care 2007;11: R3

Abstract Introduction: There is little objective comparative information about the postoperative complications of tracheostomy in morbidly obese patients. The aim of this study was to determine the incidence and severity of complications associated with open tracheostomy in critically ill morbidly obese patients during hospitalization. Methods: During a six year period, all consecutive morbidly obese patients (body mass index [BMI] of greater than o

Comparison between the Local Polynomial Kernel Method and cubic spline to Estimating Time-Varying Coefficients Model

The research deals with the study of the varying coefficient model as well as the Time-Varying Coefficient Model because of their remarkable interest in recent years. Methods Two methods were used, local polynomial kernal method and the cubic spline method. The simulation method was used for comparison. Compared to three mathematical functions that represented the variable coefficients, different sample sizes, and different levels of the model's standard deviation, the cubic spline method was best

Modeling and Performance Evaluation of a Contract-based Electronic Signature Process

Distributed systems become ubiquitous by allowing users access to a wide range of services at any time, anywhere, and from a variety of devices. In these open environments where there are many opportunities for both fraudulent services and misbehaving clients, service discovery systems are subject to security challenges. Controlling services' access is one of the fundamental issues that must be faced in the context of service discovery in distributed and open environments. Therefore, secure accesses and utilization of available services must be ensured for users. In our previous work, a contract-based approach for controlling the service access in a distributed computing context was presented. In this paper, we address the purpose and the usage of digital signature on negotiated electronic queries between a server and clients in service discovery systems and web service composition. The paper discusses the combined use of Timed Event Graphs and (max, +)- algebra to model, evaluate and optimize the performance of the signature process and client requests validation by a service provider (server). Based on an optimization resource allocation algorithm, an improvement study of the quality of service offered to the clients, in terms of waiting times and validation of their requests, is proposed. The results are reported and show the efficiency of the use of the proposed formal tools for performance analysis, evaluation and tuning of the considered process

Performance Study of Workflow Patterns-Based Web Service Composition

Web services are currently used by organizations to share their knowledge over the network and facilitate business to-business collaboration. However, combining Web services to satisfy user requests is a complex process. Workflow patterns are widely used for Web service composition to allow the specification of composite services. In this paper, the performance evaluation and analysis of workflow patterns is presented. We use both (max, +) algebra and Petri Nets as formal modeling tools to describe the behavior of workflow patterns and analyze their properties and performances. A real case study is worked out to represent and study the performances of integrated workflow patterns.Peer reviewe

A study of users’ acceptance and satisfaction of emergency call service

International audienceIn recent years, there has been rapid and significant development of road transport technologies in order toreduce the number of killed and injured people on roads. These include safety technologies, emergency callsystems (eCall), and advanced traveler information systems. The eCall system is an automatic in-vehicleemergency call service, which is mainly used for notifying emergency services about dangerous road situationsand their exact location. In this paper, an eCall platform prototype is developed to allow quick andefficient rescue of injured people in dangerous road situations. The eCall function is developed and installedin nomadic devices (e.g., smartphones and tablets). Large-scale field operational tests were conducted in realsettings to assess the impacts of the eCall function provided by in-vehicle nomadic devices. More precisely,experiments were conducted by more than 250 participants with different sociodemographic profiles in orderto study the users’ acceptance of the use of the developed eCall function for large-scale usage. The collecteddata are analyzed, and results are reported. Performed experiments showed the usefulness,acceptance, and satisfactory performance of the eCall service

A comprehensive health effects assessment of the use of sanitizers and disinfectants during COVID-19 pandemic: a global survey

COVID-19 has affected all aspects of human life so far. From the outset of the pandemic, preventing the spread of COVID-19 through the observance of health protocols, especially the use of sanitizers and disinfectants was given more attention. Despite the effectiveness of disinfection chemicals in controlling and preventing COVID-19, there are critical concerns about their adverse effects on human health. This study aims to assess the health effects of sanitizers and disinfectants on a global scale. A total of 91,056 participants from 154 countries participated in this cross-sectional study. Information on the use of sanitizers and disinfectants and health was collected using an electronic questionnaire, which was translated into 26 languages via web-based platforms. The findings of this study suggest that detergents, alcohol-based substances, and chlorinated compounds emerged as the most prevalent chemical agents compared to other sanitizers and disinfectants examined. Most frequently reported health issues include skin effects and respiratory effects. The Chi-square test showed a significant association between chlorinated compounds (sodium hypochlorite and per-chlorine) with all possible health effects under investigation (p-value <0.001). Examination of risk factors based on multivariate logistic regression analysis showed that alcohols and alcohols-based materials were associated with skin effects (OR, 1.98; 95%CI, 1.87-2.09), per-chlorine was associated with eye effects (OR, 1.83; 95%CI, 1.74-1.93), and highly likely with itching and throat irritation (OR, 2.00; 95%CI, 1.90-2.11). Furthermore, formaldehyde was associated with a higher prevalence of neurological effects (OR, 2.17; 95%CI, 1.92-2.44). Furthermore, formaldehyde was associated with a higher prevalence of neurological effects (OR, 2.17; 95%CI, 1.92-2.44). The use of sodium hypochlorite and per-chlorine also had a high chance of having respiratory effects. The findings of the current study suggest that health authorities need to implement more awareness programs about the side effects of using sanitizers and disinfectants during viral epidemics especially when they are used or overused