Performance and efficiency optimization of multi-layer IoT edge architecture

Abstract. Internet of Things (IoT) has become a backbone technology that connects together various devices with diverse capabilities. It is a technology, which enables ubiquitously available digital services for end-users. IoT applications for mission-critical scenarios need strict performance indicators such as of latency, scalability, security and privacy. To fulfil these requirements, IoT also requires support from relevant enabling technologies, such as cloud, edge, virtualization and fifth generation mobile communication (5G) technologies. For Latency-critical applications and services, long routes between the traditional cloud server and end-devices (sensors /actuators) is not a feasible approach for computing at these data centres, although these traditional clouds provide very high computational and storage for current IoT system. MEC model can be used to overcome this challenge, which brings the CC computational capacity within or next on the access network base stations. However, the capacity to perform the most critical processes at the local network layer is often necessary to cope with the access network issues. Therefore, this thesis compares the two existing IoT models such as traditional cloud-IoT model, a MEC-based edge-cloud-IoT model, with proposed local edge-cloud-IoT model with respect to their performance and efficiency, using iFogSim simulator. The results consolidate our research team’s previous findings that utilizing the three-tier edge-IoT architecture, capable of optimally utilizing the computational capacity of each of the three tiers, is an effective measure to reduce energy consumption, improve end-to-end latency and minimize operational costs in latency-critical It applications

Interpretation of creep crack growth data for ½ CMV steel weldments

Abstract½Cr½ Mo¼ V (½ CMV) steel has been used in high temperature power plant piping due to its enhanced weld properties. Creep crack growth testing has been performed on compact tension C(T) specimens of ½CMV (low alloy ferritic) steel at 540◦C on both parent metal specimens as well as fine and coarse grained heat affected zone (HAZ) specimens, where the initial crack is located within the HAZ. The data has been interpreted using the fracture mechanics parameter C* against the crack growth rate. The creep toughness parameter, Kcmat, is also evaluated for the material. It was seen that, for a given C* value, the fine grained HAZ material generally exhibits higher crack growth rates than the post weld heat treated coarse grained HAZ

Distributed network and service architecture for future digital healthcare

According to World Health Organization (WHO), the worldwide prevalence of chronic diseases increases fast and new threats, such as Covid-19 pandemic, continue to emerge, while the aging population continues decaying the dependency ratio. These challenges will cause a huge pressure on the efficacy and cost-efficiency of healthcare systems worldwide. Thanks to the emerging technologies, such as novel medical imaging and monitoring instrumentation, and Internet of Medical Things (IoMT), more accurate and versatile patient data than ever is available for medical use. To transform the technology advancements into better outcome and improved efficiency of healthcare, seamless interoperation of the underlying key technologies needs to be ensured. Novel IoT and communication technologies, edge computing and virtualization have a major role in this transformation. In this article, we explore the combined use of these technologies for managing complex tasks of connecting patients, personnel, hospital systems, electronic health records and medical instrumentation. We summarize our joint effort of four recent scientific articles that together demonstrate the potential of the edge-cloud continuum as the base approach for providing efficient and secure distributed e-health and e-welfare services. Finally, we provide an outlook for future research needs

Creep life prediction of new and service exposed 0.5Cr-0.5Mo-0.25V steel pipework

There is a growing need to increase the reliability and safety of conventional coal-fired power plants as the UK prepares to reduce its coal-fired capacity in fulfilment of the emissions requirements set in recent years. Over the next decade, the coal-fired power plants that continue to operate will require efficient design and maintenance, such that service shutdowns and inspections are minimised. It is, therefore, fundamental that the remaining life of hazard prone areas be known and informed. A large percentage of the critical high temperature components have exceeded their “design life” of 30 to 40 years, while others are aging considerably and approaching the end of their design life. To realise the continued use of these components, methods and procedures are required to understand the current plant conditions so that the remaining life of the components can be projected. Existing creep models are largely focused on uniaxial test data. In this work, a comprehensive uniaxial and multiaxial creep test programme has been carried out to validate and incorporate existing and novel models for the life assessment of components. The material examined is 0.5Cr-0.5Mo-0.25V steel, removed from a straight pipe section after 250,000 hours of operation at 16 MPa internal steam pressure and a temperature of 843 K. Circumferentially notched bar specimens were used to induce multiaxial stress states using three different notch acuities. The skeletal stress approach was used to characterise the overall behaviour of the specimen. It was shown that creep failure is controlled by the equivalent stress. The majority of the constant load uniaxial and notched bar creep tests were carried out under accelerated conditions in air, with a number of tests carried out in an inert environment to investigate the effects of oxidation. Acceleration was achieved by increasing the stress or temperature or both. It was shown that oxidation is severe in small diameter specimens, especially at temperatures above 843 K. The effects of oxidation were seen to be detrimental on the rupture lives of laboratory specimens. A discrepancy in the axial deformation of the notched bar tests carried out in an inert environment was seen with the finite element data, which was based on a material model derived from tests carried out on air. A compendium of existing as-cast data for multiple batches of 0.5Cr-0.5Mo- 0.25V pipe and tube steel was used to fit the Wilshire model for extrapolation to service conditions. In this work, a methodology is proposed in which the Wilshire model can be used in conjunction with the life fraction rule to predict the remain- ing life of the component. The suitability of the method was assessed by comparing predictions against the results from the test programme. It was shown that the mean diameter hoop stress can be used to characterise the damage incurred in service, thus allowing creep life predictions to be made independent of the specimen location across the pipe thickness. The Wilshire model was implemented into a finite element analysis as a time-based damage law and under the assumption that creep failure is controlled by the equivalent stress. The results were compared to the ductility exhaustion approach based on the Cocks and Ashby method. Conservative rupture life predictions were made for both cases. The potential for the Wilshire model to be incorporated into the formation of a time dependent failure assessment diagram (TDFAD) was also shown. The damage in the pipe prior to testing has been characterised as being high. An admixture of grain boundary separation and cavitation was seen, with cavitation being more severe nearer to the pipe bore. Micrographs of the un-failed notches of the notched bar tests showed that damage was concentrated just ahead of the notch root, which was in agreement with what was seen in the damage contour plots of the finite element results obtained from the Cocks and Ashby damage formulations.Open Acces

Performance Analysis of 3-hop using DAF and DF over 2-hop Relaying Protocols

In wireless Communication, the need of radio spectrum increases nowadays. But in the system we are losing approximately 82-86% of spectrum most of the time due to the absence of Primary User (PU). To overcome this issue Cognitive Radio (CR) is an admirable approach. The concept of cooperative communication needs to be considering because high data rate is the demand for wireless services. Cooperative diversity in the network realized by 3-hop Decode, Amplify and Forward (DAF) and Decode and Forward (DF) and in 2-hop DF and Amplify and Forward (AF) Protocols implemented in cognitive radio communication network using Orthogonal Space Time Block Coding (OSTBC). The communication between end points is accomplished by using Multiple Input and Multiple Output (MIMO) antenna arrangement. During the Propagation, Alamouti Space Time Block Coding is used to accomplish spatial diversity and the encoded data is transmitted through Rayleigh fading channel. CR decodes the transmitted signal using Maximum Likelihood (ML) decoding method. Afterward signal broadcast toward the destination. To check the energy level of signal, energy detection technique applies at the Cognitive Controller (CC). Finally, CC will take ultimate decision for the presence of primary user if the energy level of signal is greater than predefined threshold level, it means PU is present otherwise it is absent. The main objective of this thesis is to analyze the performance of 3-hop and 2-hop communication network using relays. The performance is compared on the bases of two parameters i.e. Bit Error Rate (BER) and Probability of Detection (PD). The results are processed and validated by MATLAB simulation

Health-BlockEdge: Blockchain-Edge Framework for Reliable Low-Latency Digital Healthcare Applications

The rapid evolution of technology allows the healthcare sector to adopt intelligent, context-aware, secure, and ubiquitous healthcare services. Together with the global trend of an aging population, it has become highly important to propose value-creating, yet cost-efficient digital solutions for healthcare systems. These solutions should provide effective means of healthcare services in both the hospital and home care scenarios. In this paper, we focused on the latter case, where the goal was to provide easy-to-use, reliable, and secure remote monitoring and aid for elderly persons at their home. We proposed a framework to integrate the capabilities of edge computing and blockchain technology to address some of the key requirements of smart remote healthcare systems, such as long operating times, low cost, resilience to network problems, security, and trust in highly dynamic network conditions. In order to assess the feasibility of our approach, we evaluated the performance of our framework in terms of latency, power consumption, network utilization, and computational load, compared to a scenario where no blockchain was used

Performance and efficiency optimization of multi-layer IoT edge architecture

Abstract The recent IoT applications set strict requirements in terms of latency, scalability, security and privacy. The current IoT systems, where computation is done at data centers, provide typically very high computational and storage capacity but long routes between computational capacity and sensors/actuators make them unsuitable for latency-critical applications and services. Mobile Edge Computing (MEC) can address these problems by bringing computational capacity within or next to the base stations of access networks. Furthermore, to cope with access network problems, the capability of providing the most critical processes at the local network layer is also important. Therefore, in this paper, we compare the traditional cloud-IoT model, a MEC-based edge-cloud-IoT model, and a local edge-cloud-IoT model with respect to their performance and efficiency, using iFogSim simulator. The results complement our previous findings that utilizing the three-tier edge-IoT architecture, capable of optimally utilizing the computational capacity of each of the three tiers, is an effective measure to reduce energy consumption, improve end-to-end latency and minimize operational costs in latency-critical IoT applications

Distributed network and service architecture for future digital healthcare

Abstract According to World Health Organization (WHO), the worldwide prevalence of chronic diseases increases fast and new threats, such as Covid-19 pandemic, continue to emerge, while the aging population continues decaying the dependency ratio. These challenges will cause a huge pressure on the efficacy and cost-efficiency of healthcare systems worldwide. Thanks to the emerging technologies, such as novel medical imaging and monitoring instrumentation, and Internet of Medical Things (IoMT), more accurate and versatile patient data than ever is available for medical use. To transform the technology advancements into better outcome and improved efficiency of healthcare, seamless interoperation of the underlying key technologies needs to be ensured. Novel IoT and communication technologies, edge computing and virtualization have a major role in this transformation. In this article, we explore the combined use of these technologies for managing complex tasks of connecting patients, personnel, hospital systems, electronic health records and medical instrumentation. We summarize our joint effort of four recent scientific articles that together demonstrate the potential of the edge-cloud continuum as the base approach for providing efficient and secure distributed e-health and e-welfare services. Finally, we provide an outlook for future research needs

Health-BlockEdge:blockchain-edge framework for reliable low-latency digital healthcare applications

Abstract The rapid evolution of technology allows the healthcare sector to adopt intelligent, context-aware, secure, and ubiquitous healthcare services. Together with the global trend of an aging population, it has become highly important to propose value-creating, yet cost-efficient digital solutions for healthcare systems. These solutions should provide effective means of healthcare services in both the hospital and home care scenarios. In this paper, we focused on the latter case, where the goal was to provide easy-to-use, reliable, and secure remote monitoring and aid for elderly persons at their home. We proposed a framework to integrate the capabilities of edge computing and blockchain technology to address some of the key requirements of smart remote healthcare systems, such as long operating times, low cost, resilience to network problems, security, and trust in highly dynamic network conditions. In order to assess the feasibility of our approach, we evaluated the performance of our framework in terms of latency, power consumption, network utilization, and computational load, compared to a scenario where no blockchain was used

Distributed network and service architecture for future digital healthcare

According to World Health Organization (WHO), the worldwide prevalence of chronic diseases increases fast and new threats, such as Covid-19 pandemic, continue to emerge, while the aging population continues decaying the dependency ratio. These challenges will cause a huge pressure on the efficacy and cost-efficiency of healthcare systems worldwide. Thanks to the emerging technologies, such as novel medical imaging and monitoring instrumentation, and Internet of Medical Things (IoMT), more accurate and versatile patient data than ever is available for medical use. To transform the technology advancements into better outcome and improved efficiency of healthcare, seamless interoperation of the underlying key technologies needs to be ensured. Novel IoT and communication technologies, edge computing and virtualization have a major role in this transformation. In this article, we explore the combined use of these technologies for managing complex tasks of connecting patients, personnel, hospital systems, electronic health records and medical instrumentation. We summarize our joint effort of four recent scientific articles that together demonstrate the potential of the edge-cloud continuum as the base approach for providing efficient and secure distributed e-health and e-welfare services. Finally, we provide an outlook for future research needs