The security and privacy of electronic healthcare records (EHRs) remain a critical issue for both healthcare services consumers and providers. Breaching a healthcare system causes the disclosure of ...sensitive health data. This data is usually saved into centralized databases, which creates vulnerabilities and gives rise to cyber attacks. This research focuses on enhancing the security and privacy of EHRs by using blockchain technology. This paper proposes a new architecture that takes advantage of decentralized databases to avoid centralized storage issues. The decentralized used database for storing patient electronic health records is the OrbitDB with Interplanetary File System (IPFS). Besides, we have deployed a blockchain network built on Hyperledger fabric by using Hyperledger composer to save hashes of stored data and control access when retrieving it. The proposed Blockchain-based architecture is designed to contribute to the healthcare management systems’ robustness and to avoid recorded security limitations in commonly used systems for smart healthcare. Performance evaluation results issued from Hyperledger Caliper and comparative analysis have proved the robustness and superiority of the proposed system in terms of security and privacy requirements, key features of blockchain-based healthcare systems, and performance metrics including various throughput and latency.
•An RPM and EHR sharing System is proposed based on Blockchain technology.•A decentralized Offchain database (Orbit DB with IPFS) is used to store medical data.•A smart contract is executed through Hyperledger Fabric network for access control.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Internet of things (IoT) for precision agriculture or Smart Farming (SF) is an emerging area of application. It consists essentially of deploying wireless networks of IP-enabled sensor nodes in a ...partitioned farmland area. When the surface, diversity, and complexity of the farm increases, the number of sensing nodes increases, generating heavy exchange of data and messages, and thus leading to network congestion, radio interference, and high energy consumption. In this work, we propose a novel routing algorithm extending the well known IPv6 Routing Protocol for Low power and Lossy Networks (RPL). It is referred to as the Partition Aware-RPL (PA-RPL). that improves the standard IoT routing algorithm (i.e., RPL). In contrast to RPL, the proposed technique builds a routing topology enabling efficient in-network data aggregation, hence dramatically reducing data traffic through the network. Performance analysis of a typical/realistic precision agriculture case, considering the potato pest prevention from the well-known late blight disease, shows that PA-RPL improves energy saving up to 40 % , compared to standard RPL.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The Internet of Things (IoT) has emerged as a paradigm over the last few years as a result of the tight integration of the computing and the physical world. The requirement of remote sensing makes ...low-power wireless sensor networks one of the key enabling technologies of IoT. These networks encompass several challenges, especially in communication and networking, due to their inherent constraints of low-power features, deployment in harsh and lossy environments, and limited computing and storage resources. The IPv6 Routing Protocol for Low Power and Lossy Networks (RPL) 1 was proposed by the IETF ROLL (Routing Over Low-power Lossy links) working group and is currently adopted as an IETF standard in the RFC 6550 since March 2012. Although RPL greatly satisfied the requirements of low-power and lossy sensor networks, several issues remain open for improvement and specification, in particular with respect to Quality of Service (QoS) guarantees and support for mobility.
In this paper, we focus mainly on the RPL routing protocol. We propose some enhancements to the standard specification in order to provide QoS guarantees for static as well as mobile LLNs. For this purpose, we propose OF-FL (Objective Function based on Fuzzy Logic), a new objective function that overcomes the limitations of the standardized objective functions that were designed for RPL by considering important link and node metrics, namely end-to-end delay, number of hops, ETX (Expected transmission count) and LQL (Link Quality Level). In addition, we present the design of Co-RPL, an extension to RPL based on the corona mechanism that supports mobility in order to overcome the problem of slow reactivity to frequent topology changes and thus providing a better quality of service mainly in dynamic networks application. Performance evaluation results show that both OF-FL and Co-RPL allow a great improvement when compared to the standard specification, mainly in terms of packet loss ratio and average network latency.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Diesel engines, especially for trucks and buses, cause many economical and ecological problems. Diesel exhaust emissions are a major source of pollution in most urban centers around the world. ...Furthermore, the price of crude oil continues to increase rapidly. The use of alternative fuels (liquified petroleum gas, LPG and compressed natural gas, CNG) and the optimization of combustion present effective solutions. Improving combustion is directly related to improving the intake aerodynamic movements which is influenced by the inlet system, especially the intake manifold. In this paper we have studied the geometry effects of two intake manifolds on the in-cylinder flows by two methods, numerically and experimentally. These two manifolds are mounted on a fully instrumented, six-cylinder, 13.8
l displacement, heavy duty, IVECO engine, installed at the authors’ laboratory, which is used to power the urban bus diesel engines in Sfax. This engine was modified to bi-fuel spark ignition engine gasoline and gas fuelling. The 1st manifold presents an unspecified geometry whereas the 2nd presents an optimal filling geometry.
A three-dimensional numerical modeling of the turbulent in-cylinder flow through the two manifolds was undertaken. The model is based on solving Navier–Stokes and energy equations in conjunction with the standard
k–
ε turbulence model, using the 3D CFD code FloWorks. This modeling made it possible to provide a fine knowledge of in-flow structures, in order to examine the adequate manifold. Experimental measurements are also carried out to validate this manifold by measuring the important engine performances. Brake power (BP), brake torque (BT) and brake thermal efficiency (BTE), are increased by 16%, 13.9%, and 12.5%, respectively, using optimal manifold. The brake specific fuel consumption (BSFC) is reduced by 28%. Simulation and experiments results confirmed the benefits of the optimized manifold geometry on the in-cylinder flow and engine performances.
► The influence of the intake manifold geometry is studied on a converted gas engine. ► In-cylinder flow modeling is made using CFD through two manifold designs. ► An experimental comparison is made between manifolds by testing engine performances
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Combustion characteristics and emission in spark-ignition engines could be enhanced using hydrogen as supplementary fuel. However, its production, storage, and introduction in the combustion chamber ...face several challenges. To overcome the necessity of a storage device, a conventional electrolyser was used to produce a hydrogen-oxygen mixture (hydroxygen). The produced hydroxygen bubbles are characterized by their macro and nanometric size. In the present work, gasoline was on top of the water in the electrolyser. Therefore, hydroxygen nanobubbles are diffused in both water and gasoline. Combustion analysis was carried out for different engine speeds. An improvement in brake torque and a reduction in fuel consumption, HC, CO, and CO
2
emissions have been witnessed in the engine during test performance. However, the emission analysis shows a slight increase in NO
x
emission. Finally, this disadvantage could be neglected compared to the improvements that come with the use of hydroxygen nanobubble gasoline blends.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Wireless Sensor Networks (WSNs) are prone to highly constrained resources, as a result ensuring the proper functioning of the network is a requirement. Therefore, an effective WSN management system ...has to be integrated for the network efficiency. Our objective is to model, design, and propose a homogeneous WSN hybrid architecture. This work features a dedicated power utilization optimization strategy specifically for WSNs application. It is entitled Hybrid Energy-Efficient Power manager Scheduling (HEEPS). The pillars of this strategy are based on the one hand on time-out Dynamic Power Management (DPM) Intertask and on the other hand on Dynamic Voltage and Frequency Scaling (DVFS). All tasks are scheduled under Global Earliest Deadline First (GEDF) with new scheduling tests to overcome the Dhall effect. To minimize the energy consumption, the HEEPS predicts, defines and models the behavior adapted to each sensor node, as well as the associated energy management mechanism. HEEPS's performance evaluation and analysis are performed using the STORM simulator. A comparison to the results obtained with the various state of the art approaches is presented. Results show that the power manager proposed effectively schedules tasks to use dynamically the available energy estimated gain up to 50%.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The all sky surveys done by the Palomar Observatory Schmidt, the European Southern Observatory Schmidt, and the United Kingdom Schmidt, the InfraRed Astronomical Satellite, and the Two Micron All Sky ...Survey have proven to be extremely useful tools for astronomy with value that lasts for decades. The Wide-field Infrared Survey Explorer (WISE) is mapping the whole sky following its launch on 2009 December 14. WISE began surveying the sky on 2010 January 14 and completed its first full coverage of the sky on July 17. The survey will continue to cover the sky a second time until the cryogen is exhausted (anticipated in 2010 November). WISE is achieving 5 Delta *s point source sensitivities better than 0.0,0.11, 1, and 6 mJy in unconfused regions on the ecliptic in bands centered at wavelengths of 3.4, 4.6, 12, and 22 Delta *mm. Sensitivity improves toward the ecliptic poles due to denser coverage and lower zodiacal background. The angular resolution is 61, 64, 65, and 120 at 3.4, 4.6, 12, and 22 Delta *mm, and the astrometric precision for high signal-to-noise sources is better than 015.
Miniaturized spectrometers have great potential for use in portable optoelectronics and wearable sensors. However, current strategies for miniaturization rely on von Neumann architectures, which ...separate the spectral sensing, storage, and processing modules spatially, resulting in high energy consumption and limited processing speeds due to the storage-wall problem. Here, we present a miniaturized spectrometer that utilizes a single SnS
/ReSe
van der Waals heterostructure, providing photodetection, spectrum reconstruction, spectral imaging, long-term image memory, and signal processing capabilities. Interface trap states are found to induce a gate-tunable and wavelength-dependent photogating effect and a non-volatile optoelectronic memory effect. Our approach achieves a footprint of 19 μm, a bandwidth from 400 to 800 nm, a spectral resolution of 5 nm, and a > 10
s long-term image memory. Our single-detector computational spectrometer represents a path beyond von Neumann architectures.
Nowadays, several universities and institutions make profit from the information technologies to enhance and develop their educational strategies and attract more learners. Therefore, distance ...learning (e-learning) and learning-on-the-go are technologies adopted by universities and service providers to afford more flexible education system. In fact, e-learning is gaining popularity worldwide and the number of learners enrolled in on-line courses is growing. This trend is explained mainly by the opportunities provided by Cloud Computing. In the cloud based educational context, the security factor in sharing the educational content is important and poses several security challenges, such as fine-grained access control and security preservation of content learning. Moreover, there is emergence of the new concept of User-Fog-Cloud architecture to bring closer the services to the client. In this paper, a new fog computing e-learning scheme is provided. Specifically, the proposed solution extends learning content from the cloud to the edge of the network. It can improve the efficiency of learning data analysis, reduces the encryption burden in terms of computation cost on user's devices by offloading part of encryption cost to fog servers and provides fine grained access control to learning content by encrypting the course and the exam with different cryptographic techniques like IBBE and CP-ABE. Further, we present a profile matching mechanism that helps teachers to find colleagues within their vicinity in an efficient and secure way. Security analysis shows that our scheme can achieve data confidentiality, fine-grained access control, collusion resistance and unforgeability. Performance evaluations demonstrate the efficiency of our solution, especially in terms of encryption computation costs.
PDF
