Karim Djouani - Profile on Academia.edu (original) (raw)
Papers by Karim Djouani
Electronics
With the availability of modern assistive techniques, ambient intelligence, and the Internet of T... more With the availability of modern assistive techniques, ambient intelligence, and the Internet of Things (IoT), various innovative assistive environments have been developed, such as driving assistance systems (DAS), where the human driver can be provided with physical and emotional assistance. In this human–machine collaboration system, haptic interaction interfaces are commonly employed because they provide drivers with a more manageable way to interact with other components. From the view of control system theory, this is a typical closed-loop feedback control system with a human in the loop. To make such a system work effectively, both the driving behaviour factors, and the electrical–mechanical components should be considered. However, the main challenge is how to deal with the high degree of uncertainties in human behaviour. This paper aims to provide an insightful overview of the relevant work. The impact of various types of haptic assistive driving systems (haptic guidance and...
Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access an... more Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access and route high volumes of traffic simultaneously. Such roles demand high network capacity, and long "online" time at the expense of accelerated transmission energy depletion and poor connectivity. This is the problem of transmission power control. Numerous power control methods for wireless networks are in literature. However, contributions towards MRMC configurations still face many challenges worth considering. In this paper, an energy-efficient power selection protocol called PMMUP is suggested at the Link-Layer. This protocol first divides the MRMC-WMN into a set of unified channel graphs (UCGs). A UCG consists of multiple radios interconnected to each other via a common wireless channel. In each UCG, a stochastic linear quadratic cost function is formulated. Each user minimizes this cost function consisting of trade-off between the size of unification states and the control ...
Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh netwo... more Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh networks (WMNs). In this paper, we present asynchronous multiple-state based power control for MRMC WMNs. First, WMN is represented as a set of disjoint Unified Channel Graphs (UCGs). Second, each network interface card (NIC) or radio assigned to a unique UCG adjusts transmission power using predicted multiple interaction state variables (IV) across UCGs. Depending on the size of queue loads and intra- and inter-channel states, each NIC optimizes transmission power locally and asynchronously. A new power selection MRMC unification protocol (PMMUP) is proposed that coordinates interactions among radios. The efficacy of the proposed method is investigated through simulations.
Technologies, 2022
Visible light communications (VLC) is an emerging and promising concept that is capable of solvin... more Visible light communications (VLC) is an emerging and promising concept that is capable of solving the major challenges of 5G and Internet of Things (IoT) communication systems. Moreover, due to the usage of light-emitting diodes (LEDs) in almost every aspect of our daily life VLC is providing massive connectivity for various types of massive IoT communications ranging from machine-to-machine, vehicle-to-infrastructure, infrastructure-to-vehicle, chip-to-chip as well as device-to-device. In this paper, we undertake a comprehensive review of the prospects of implementing VLC for IoT. Moreover, we investigate existing and proposed approaches implemented in the application of VLC for IoT. Additionally, we look at the challenges faced in applying VLC for IoT and offer solutions where applicable. Then, we identify future research directions in the implementation of VLC for IoT.
IEEE Access, 2022
Smartgrid is a paradigm that was introduced into the conventional electricity network to enhance ... more Smartgrid is a paradigm that was introduced into the conventional electricity network to enhance the way generation, transmission, and distribution networks interrelate. It involves the use of Information and Communication Technology (ICT) and other solution in fault and intrusion detection, mere monitoring of energy generation, transmission, and distribution. However, on one hand, the actual and earlier smartgrid, do not integrate more advanced features such as automatic decision making, security, scalability, self-healing and awareness, real-time monitoring, cross-layer compatibility, etc. On the other hand, the emergence of the digitalization of the communication infrastructure to support the economic sector which among them are energy generation and distribution grid with Artificial Intelligence (AI) and largescale Machine to Machine (M2M) communication. With the future Massive Internet of Things (MIoT) as one of the pillars of 5G/6G network factory, it is the enabler to support the next generation smart grid by providing the needed platform that integrates, in addition to the communication infrastructure, the AI and IoT support, providing a multitenant system. This paper aim at presenting a comprehensive review of next smart grid research trends and technological background, discuss a futuristic next-generation smart grid driven by artificial intelligence (AI) and leverage by IoT and 5G. In addition, it discusses the challenges of nextgeneration smart-grids as it relate to the integration of AI, IoT and 5G for better smart grid architecture. Also, proffers possible solutions to some of the challenges and standards to support this novel trend. A corresponding future work will dwell on the implementation of the discussed integration of AI, IoT and 5G for next-generation smart grid, using Matlab, NS2/NS3, Open-daylight and Mininet as soft tools and compare with related literature. INDEX TERMS 5G, artificial intelligence (AI), Internet of Things (IoT), next-generation smartgrid, network slicing.
In this paper we present a methodology for optimal force distribution calculation for the multipl... more In this paper we present a methodology for optimal force distribution calculation for the multiple manipulators system grasping an object.We consider for this case three robots holding a common rigid object with three contact points , where the object can translate and rotate in any directions. This approach is used in the case of real time dynamics object force control. The force distribution problem is formulated in terms of a nonlinear programming problem under equality and inequality constraints. Then, according to [1],[2],[3] and [4] the friction constraints are transformed from non linear inequalities into a combination of linear equalities and linear inequalities. The original non linear constrained programming problem is then transformed into a quadratic optimization problem. Some simulation results are given to show the efficiency and accuracy of the proposed methodology and perspectives on multiple manipulators system grasping an object control are discussed.
According to recent studies, billions of objects are expected to be connected wirelessly by 2020.... more According to recent studies, billions of objects are expected to be connected wirelessly by 2020. The Low Power Wide Area (LPWA) networks are already playing an important role in connecting billions of new devices making up the IoT. Long Range (LoRa) and Narrowband-IoT (NB-IoT) are currently the two leading technologies triggering considerable research interest. This paper focuses on providing a comprehensive and comparative survey study on the current research and industrial states of NB-IoT and LoRa in terms of their power efficiency, their capacity, quality of service (QoS), reliability and range of coverage. The outcome of this research survey demonstrates that the unlicensed LoRa is more advantageous than the NBIoT in terms of its energy efficiency, its capacity and cost while the NB-IoT gives benefits in terms of its reliability, resilience to interference, latency and QoS. It is further shown that despite the considerable research and development that has so far been carried ...
IFAC-PapersOnLine, 2020
This paper concerns adaptive sliding-mode control for wearable robots with a human in the loop. T... more This paper concerns adaptive sliding-mode control for wearable robots with a human in the loop. The exoskeletons are wearable robots in interaction with different users. The proposed approach supposes that the dynamic model of the exoskeleton-human system is unknown except for some classical bounded properties. The controller guarantees the closedloop convergence with an embedded-in estimation of unknown dynamics and uncertainties. The stability analysis of the system is demonstrated using the Lyapunov theory. Experimentation on an upper arm exoskeleton was conducted in order to exhibit the effectiveness of the proposed control method. The results show good tracking of the desired trajectories, which can be used in the assistive phase of the functional rehabilitation.
Robotics, 2021
Disabilities are a global issue due to the decrease in life quality and mobility of patients, esp... more Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human...
IEEE Access, 2020
The novel coronavirus (COVID-19), declared by the World Health Organization (WHO) as a global pan... more The novel coronavirus (COVID-19), declared by the World Health Organization (WHO) as a global pandemic, has brought with it changes to the general way of life. Major sectors of the world industry and economy have been affected and the Internet of Things (IoT) management and framework is no exception in this regard. This article provides an up to date survey on how a global pandemic such as COVID-19 has affected the world of IoT technologies. It looks at the contributions that IoT and associated sensor technologies have made towards virus tracing, tracking and spread mitigation. The associated challenges of deployment of sensor hardware in the face of a rapidly spreading pandemic have been looked into as part of this review article. The effects of a global pandemic on the evolution of IoT architectures and management have also been addressed, leading to the likely outcomes on future IoT implementations. In general, this article provides an insight into the advancement of sensor-based E-health towards the management of global pandemics. It also answers the question of how a global virus pandemic has shaped the future of IoT networks. INDEX TERMS Artificial intelligence, big data, COVID-19, data sharing, internet of things, pandemic management.
Robotics, 2021
The capabilities of collaborative robotics have transcended the conventional abilities of decentr... more The capabilities of collaborative robotics have transcended the conventional abilities of decentralised robots as it provides benefits such as scalability, flexibility and robustness. Collaborative robots can operate safely in complex human environments without being restricted by the safety cages or barriers that often accompany them. Collaborative robots can be used for various applications such as machine tending, packaging, process tasks and pick and place. This paper proposes an improvement of the current virtual impedance algorithm by developing an adaptive virtual impedance controlled mobile multi-robot system focused on dynamic obstacle avoidance with a controlled planar movement. The study includes the development of a mobile multi-robot platform whereby each robot plans a path individually without a supervisor. The proposed system would implement a two-layered hierarchy for robot path planning. The higher layer generates a trajectory from the current position to the desire...
Sensors, 2020
The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) ... more The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) technology for accommodating massive device connections in 5G and beyond. To enable network scalability, this study proposes a two-layers novel mixed approach that aims not only to create an efficient spectrum sharing among the many NB-IoT devices but also provides an energy-efficient network. On one layer, the approach uses an Adaptive Frequency Hopping Spread Spectrum (AFHSS) technique that uses a lightweight and secure pseudo-random sequence to exploit the channel diversity, to mitigate inter-link and cross-technology interference. On the second layer, the approach consists of a clustering and network coding (data aggregation) approach based on an energy-signal strength mixed gradient. The second layer contributes to offload the BS, allows for energy-efficient network scalability, helps balance the energy consumption of the network, and enhances the overall network lifetime. The propo...
Sensors, 2020
Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enh... more Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enhancing its network coverage. Many of the existing NB-IoT channel coding techniques are based on repeating transmission data and control signals as a way of enhancing the network’s reliability and therefore, enabling long-distance transmissions. Although most of these efforts are made at the expense of reducing the energy consumption of the NB-IoT network, they do not always consider the channel conditions. Therefore, this work proposes a novel NB-IoT Energy-Efficient Adaptive Channel Coding (EEACC) scheme. The EEACC approach is a two-dimensional (2D) approach which not only selects an appropriate channel coding scheme based on the estimated channel conditions (dynamically classified as bad, medium or good from initial based on a periodically assessed BLER performance outcome) but also minimizes the transmission repetition number under a pre-assessed probability of successful transmission...
IEEE Access, 2020
The Narrowband Internet of Things (NB-IoT) has been introduced in the 3rd Generation Partnership ... more The Narrowband Internet of Things (NB-IoT) has been introduced in the 3rd Generation Partnership Project (3GPP) Rel-13 with the aim to provide low-cost, low-power, wide-area cellular connectivity for the Internet of Things. With the exponentially increasing number of connected wireless devices in the order of 100 billion, it has become crucial that researchers develop efficient resource management techniques to meet the 5 th Generation (5G) quality of service (QoS) requirements. Recently, several research challenges including the low modulation data rates, energy-expensive channel coding techniques, and the fast-growing number of connected devices have been identified as some of the main issues encountered in the design and deployment of NB-IoT systems. In addition, several techniques have emerged in the literature to resolve some of these challenges of NB-IoT systems. However, the research activities towards the enhancement of the NB-IoT resource management are yet to continue in the next half-decade before, high data rates, energyefficient, and scalable NB-IoT specifications can be released for the standardisation and commercialisation. Considering the limited number of existing surveys of such technical enhancement approaches in a broader perspective (i.e. energy efficiency, data rate performance and scalability) and also the non-existence, to the best of our knowledge, of a comparative survey, this paper seeks to elaborate, describe and compare the performances of such resources management approaches. Of the multiple NB-IoT resources, the focus of this paper is on the data rate, energy efficiency, and scalability enhancement schemes that have been proposed for the last three years. The contribution of the paper lies in the analysis, synthesis, comparison and summarised alignments of some of the major existing schemes towards identifying challenges faced by the NB-IoT development. Finally, this work seeks to identify research challenges, open questions, and opportunities that could arise from the existing techniques analysed. INDEX TERMS Data rates, energy efficient, challenges, narrowband IoT (NB-IoT), opportunities, resources, scalability, reliability.
International Journal on AdHoc Networking Systems, 2018
In recent times, the use of Smart antennas (SA) in wireless communications has greatly increased;... more In recent times, the use of Smart antennas (SA) in wireless communications has greatly increased; this is because of their ability to increase the coverage and capacity of a network. There are two main functions which SAs perform: direction of arrival (DOA) and beamforming. SAs are able to produce the main beams towards a desired user and at the same time, form nulls in the direction of interfering signals. They are able to achieve this by the use of beamforming algorithms. The performance of an enhanced Recursive Least Squares (RLS) algorithm which takes into account an enhanced gain factor of the RLS algorithm is evaluated in this paper for adaptive array beamforming. Simulation results show that the enhanced RLS reduces mean square error (MSE), smoothens filter output improves SNR;thus, improving the gain of the RLS algorithm. The result of this work will lead to an increased range of beamforming and directivity of the smart antenna over a long range communication network.
Role Based Access Control (RBAC) is one of the most used models in designing and implementation o... more Role Based Access Control (RBAC) is one of the most used models in designing and implementation of security policies in large networking systems. The classical model doesn't consider temporal aspects which are so important in such policies. Temporal RBAC (TRBAC) is proposed to deal with these aspects. Although the elegance of these models, design a security policy remains a challenge. One is obliged to prove the consistency and the correctness of the policy. Using formal verification allows proving that the designed policy is consistent. In this paper 1 , we present a formal modelling/analysis approach for TRBAC policies. We use Timed Colored Petri Nets to model the TRBAC policy, and then CPN-tool is used to analyze the generated models. The analysis allows proving many important properties about the TRBAC security policy.
Computational and mathematical methods in medicine, 2018
Graph cut segmentation provides a platform to analyze images through a global segmentation strate... more Graph cut segmentation provides a platform to analyze images through a global segmentation strategy, and as a result of this, it has gained a wider acceptability in many interactive and automatic segmentation fields of application, such as the medical field. The graph cut energy function has a parameter that is tuned to ensure that the output is neither oversegmented (shrink bias) nor undersegmented. Models have been proposed in literature towards the improvement of graph cut segmentation, in the context of interactive and automatic cell segmentation. Along this line of research, the graph cut parameter has been leveraged, while in some instances, it has been ignored. Therefore, in this work, the relevance of graph cut parameter on both interactive and automatic cell segmentation is investigated. Statistical analysis, based on F1 score, of three publicly available datasets of cells, suggests that the graph cut parameter plays a significant role in improving the segmentation accuracy...
Identification of wheelchair user steering behaviour within indoor environments
2015 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2015
The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to t... more The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to the important mobility ease they provide to people with disability. Nonetheless, users with extreme mobility impairments still experience some cognitive and physical steering challenges that limit their capacity to navigate even simple environments. Assistive wheelchairs with functionalities to enable customisation of user handicap are therefore still required. The diversity of user disabilities and needs, and the corresponding assistive measures, necessitate proper understanding of the user. Modelling and integration of user driving behaviour into the control loop in order to monitor user inputs, and execute necessary corrective steps in troublesome situations, may just be one way of providing the assistance that corresponds to needs of the user. This paper attempts to identify the steering behaviour of an individual wheelchair user in a normal living room environment. The preliminary navigation experiments required to obtain the steering data are performed in a virtual world on an augmented wheelchair platform, and the participant is observed to exhibit expected navigational behaviours. Least square method is considered in the estimation of model parameters for the non-linear steering model with interesting regression analysis outcome.
International Journal of Applied Mathematics and Computer Science, 2012
Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations d... more Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations do experience power control problems such as the inter-channel and co-channel interference, high energy consumption at multiple queues and unscalable network connectivity. Such network problems can be conveniently modelled using the theory of queue perturbation in the multiple queue systems and also as a weak coupling in a multiple channel wireless network. Consequently, this paper proposes a queue perturbation and weakly coupled based power control approach forWBNs. The ultimate objectives are to increase energy efficiency and the overall network capacity. In order to achieve this objective, a Markov chain model is first presented to describe the behaviour of the steady state probability distribution of the queue energy and buffer states. The singular perturbation parameter is approximated from the coefficients of the Taylor series expansion of the probability distribution. The impact of...
Non Destructive Sensing of Food Materials using Fuzzy c-means Clustering
Electronics
With the availability of modern assistive techniques, ambient intelligence, and the Internet of T... more With the availability of modern assistive techniques, ambient intelligence, and the Internet of Things (IoT), various innovative assistive environments have been developed, such as driving assistance systems (DAS), where the human driver can be provided with physical and emotional assistance. In this human–machine collaboration system, haptic interaction interfaces are commonly employed because they provide drivers with a more manageable way to interact with other components. From the view of control system theory, this is a typical closed-loop feedback control system with a human in the loop. To make such a system work effectively, both the driving behaviour factors, and the electrical–mechanical components should be considered. However, the main challenge is how to deal with the high degree of uncertainties in human behaviour. This paper aims to provide an insightful overview of the relevant work. The impact of various types of haptic assistive driving systems (haptic guidance and...
Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access an... more Multi-Radio Multi-Channel Wireless Mesh Networks (MRMC-WMNs) operate at the backbone to access and route high volumes of traffic simultaneously. Such roles demand high network capacity, and long "online" time at the expense of accelerated transmission energy depletion and poor connectivity. This is the problem of transmission power control. Numerous power control methods for wireless networks are in literature. However, contributions towards MRMC configurations still face many challenges worth considering. In this paper, an energy-efficient power selection protocol called PMMUP is suggested at the Link-Layer. This protocol first divides the MRMC-WMN into a set of unified channel graphs (UCGs). A UCG consists of multiple radios interconnected to each other via a common wireless channel. In each UCG, a stochastic linear quadratic cost function is formulated. Each user minimizes this cost function consisting of trade-off between the size of unification states and the control ...
Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh netwo... more Multi-Radio Multi-Channel (MRMC) systems are key to power control problems in wireless mesh networks (WMNs). In this paper, we present asynchronous multiple-state based power control for MRMC WMNs. First, WMN is represented as a set of disjoint Unified Channel Graphs (UCGs). Second, each network interface card (NIC) or radio assigned to a unique UCG adjusts transmission power using predicted multiple interaction state variables (IV) across UCGs. Depending on the size of queue loads and intra- and inter-channel states, each NIC optimizes transmission power locally and asynchronously. A new power selection MRMC unification protocol (PMMUP) is proposed that coordinates interactions among radios. The efficacy of the proposed method is investigated through simulations.
Technologies, 2022
Visible light communications (VLC) is an emerging and promising concept that is capable of solvin... more Visible light communications (VLC) is an emerging and promising concept that is capable of solving the major challenges of 5G and Internet of Things (IoT) communication systems. Moreover, due to the usage of light-emitting diodes (LEDs) in almost every aspect of our daily life VLC is providing massive connectivity for various types of massive IoT communications ranging from machine-to-machine, vehicle-to-infrastructure, infrastructure-to-vehicle, chip-to-chip as well as device-to-device. In this paper, we undertake a comprehensive review of the prospects of implementing VLC for IoT. Moreover, we investigate existing and proposed approaches implemented in the application of VLC for IoT. Additionally, we look at the challenges faced in applying VLC for IoT and offer solutions where applicable. Then, we identify future research directions in the implementation of VLC for IoT.
IEEE Access, 2022
Smartgrid is a paradigm that was introduced into the conventional electricity network to enhance ... more Smartgrid is a paradigm that was introduced into the conventional electricity network to enhance the way generation, transmission, and distribution networks interrelate. It involves the use of Information and Communication Technology (ICT) and other solution in fault and intrusion detection, mere monitoring of energy generation, transmission, and distribution. However, on one hand, the actual and earlier smartgrid, do not integrate more advanced features such as automatic decision making, security, scalability, self-healing and awareness, real-time monitoring, cross-layer compatibility, etc. On the other hand, the emergence of the digitalization of the communication infrastructure to support the economic sector which among them are energy generation and distribution grid with Artificial Intelligence (AI) and largescale Machine to Machine (M2M) communication. With the future Massive Internet of Things (MIoT) as one of the pillars of 5G/6G network factory, it is the enabler to support the next generation smart grid by providing the needed platform that integrates, in addition to the communication infrastructure, the AI and IoT support, providing a multitenant system. This paper aim at presenting a comprehensive review of next smart grid research trends and technological background, discuss a futuristic next-generation smart grid driven by artificial intelligence (AI) and leverage by IoT and 5G. In addition, it discusses the challenges of nextgeneration smart-grids as it relate to the integration of AI, IoT and 5G for better smart grid architecture. Also, proffers possible solutions to some of the challenges and standards to support this novel trend. A corresponding future work will dwell on the implementation of the discussed integration of AI, IoT and 5G for next-generation smart grid, using Matlab, NS2/NS3, Open-daylight and Mininet as soft tools and compare with related literature. INDEX TERMS 5G, artificial intelligence (AI), Internet of Things (IoT), next-generation smartgrid, network slicing.
In this paper we present a methodology for optimal force distribution calculation for the multipl... more In this paper we present a methodology for optimal force distribution calculation for the multiple manipulators system grasping an object.We consider for this case three robots holding a common rigid object with three contact points , where the object can translate and rotate in any directions. This approach is used in the case of real time dynamics object force control. The force distribution problem is formulated in terms of a nonlinear programming problem under equality and inequality constraints. Then, according to [1],[2],[3] and [4] the friction constraints are transformed from non linear inequalities into a combination of linear equalities and linear inequalities. The original non linear constrained programming problem is then transformed into a quadratic optimization problem. Some simulation results are given to show the efficiency and accuracy of the proposed methodology and perspectives on multiple manipulators system grasping an object control are discussed.
According to recent studies, billions of objects are expected to be connected wirelessly by 2020.... more According to recent studies, billions of objects are expected to be connected wirelessly by 2020. The Low Power Wide Area (LPWA) networks are already playing an important role in connecting billions of new devices making up the IoT. Long Range (LoRa) and Narrowband-IoT (NB-IoT) are currently the two leading technologies triggering considerable research interest. This paper focuses on providing a comprehensive and comparative survey study on the current research and industrial states of NB-IoT and LoRa in terms of their power efficiency, their capacity, quality of service (QoS), reliability and range of coverage. The outcome of this research survey demonstrates that the unlicensed LoRa is more advantageous than the NBIoT in terms of its energy efficiency, its capacity and cost while the NB-IoT gives benefits in terms of its reliability, resilience to interference, latency and QoS. It is further shown that despite the considerable research and development that has so far been carried ...
IFAC-PapersOnLine, 2020
This paper concerns adaptive sliding-mode control for wearable robots with a human in the loop. T... more This paper concerns adaptive sliding-mode control for wearable robots with a human in the loop. The exoskeletons are wearable robots in interaction with different users. The proposed approach supposes that the dynamic model of the exoskeleton-human system is unknown except for some classical bounded properties. The controller guarantees the closedloop convergence with an embedded-in estimation of unknown dynamics and uncertainties. The stability analysis of the system is demonstrated using the Lyapunov theory. Experimentation on an upper arm exoskeleton was conducted in order to exhibit the effectiveness of the proposed control method. The results show good tracking of the desired trajectories, which can be used in the assistive phase of the functional rehabilitation.
Robotics, 2021
Disabilities are a global issue due to the decrease in life quality and mobility of patients, esp... more Disabilities are a global issue due to the decrease in life quality and mobility of patients, especially people suffering from hand disabilities. This paper presents a review of active hand exoskeleton technologies, over the past decade, for rehabilitation, assistance, augmentation, and haptic devices. Hand exoskeletons are still an active research field due to challenges that engineers face and are trying to solve. Each hand exoskeleton has certain requirements to fulfil to achieve their aims. These requirements have been extracted and categorized into two sections: general and specific, to give a common platform for developing future devices. Since this is still a developing area, the requirements are also shaped according to the advances in the field. Technical challenges, such as size requirements, weight, ergonomics, rehabilitation, actuators, and sensors are all due to the complex anatomy and biomechanics of the hand. The hand is one of the most complex structures in the human...
IEEE Access, 2020
The novel coronavirus (COVID-19), declared by the World Health Organization (WHO) as a global pan... more The novel coronavirus (COVID-19), declared by the World Health Organization (WHO) as a global pandemic, has brought with it changes to the general way of life. Major sectors of the world industry and economy have been affected and the Internet of Things (IoT) management and framework is no exception in this regard. This article provides an up to date survey on how a global pandemic such as COVID-19 has affected the world of IoT technologies. It looks at the contributions that IoT and associated sensor technologies have made towards virus tracing, tracking and spread mitigation. The associated challenges of deployment of sensor hardware in the face of a rapidly spreading pandemic have been looked into as part of this review article. The effects of a global pandemic on the evolution of IoT architectures and management have also been addressed, leading to the likely outcomes on future IoT implementations. In general, this article provides an insight into the advancement of sensor-based E-health towards the management of global pandemics. It also answers the question of how a global virus pandemic has shaped the future of IoT networks. INDEX TERMS Artificial intelligence, big data, COVID-19, data sharing, internet of things, pandemic management.
Robotics, 2021
The capabilities of collaborative robotics have transcended the conventional abilities of decentr... more The capabilities of collaborative robotics have transcended the conventional abilities of decentralised robots as it provides benefits such as scalability, flexibility and robustness. Collaborative robots can operate safely in complex human environments without being restricted by the safety cages or barriers that often accompany them. Collaborative robots can be used for various applications such as machine tending, packaging, process tasks and pick and place. This paper proposes an improvement of the current virtual impedance algorithm by developing an adaptive virtual impedance controlled mobile multi-robot system focused on dynamic obstacle avoidance with a controlled planar movement. The study includes the development of a mobile multi-robot platform whereby each robot plans a path individually without a supervisor. The proposed system would implement a two-layered hierarchy for robot path planning. The higher layer generates a trajectory from the current position to the desire...
Sensors, 2020
The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) ... more The Narrowband Internet of Things (NB-IoT) is a very promising licensed Internet of things (IoT) technology for accommodating massive device connections in 5G and beyond. To enable network scalability, this study proposes a two-layers novel mixed approach that aims not only to create an efficient spectrum sharing among the many NB-IoT devices but also provides an energy-efficient network. On one layer, the approach uses an Adaptive Frequency Hopping Spread Spectrum (AFHSS) technique that uses a lightweight and secure pseudo-random sequence to exploit the channel diversity, to mitigate inter-link and cross-technology interference. On the second layer, the approach consists of a clustering and network coding (data aggregation) approach based on an energy-signal strength mixed gradient. The second layer contributes to offload the BS, allows for energy-efficient network scalability, helps balance the energy consumption of the network, and enhances the overall network lifetime. The propo...
Sensors, 2020
Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enh... more Most of the current research work on the Narrowband Internet of Things (NB-IoT) is focused on enhancing its network coverage. Many of the existing NB-IoT channel coding techniques are based on repeating transmission data and control signals as a way of enhancing the network’s reliability and therefore, enabling long-distance transmissions. Although most of these efforts are made at the expense of reducing the energy consumption of the NB-IoT network, they do not always consider the channel conditions. Therefore, this work proposes a novel NB-IoT Energy-Efficient Adaptive Channel Coding (EEACC) scheme. The EEACC approach is a two-dimensional (2D) approach which not only selects an appropriate channel coding scheme based on the estimated channel conditions (dynamically classified as bad, medium or good from initial based on a periodically assessed BLER performance outcome) but also minimizes the transmission repetition number under a pre-assessed probability of successful transmission...
IEEE Access, 2020
The Narrowband Internet of Things (NB-IoT) has been introduced in the 3rd Generation Partnership ... more The Narrowband Internet of Things (NB-IoT) has been introduced in the 3rd Generation Partnership Project (3GPP) Rel-13 with the aim to provide low-cost, low-power, wide-area cellular connectivity for the Internet of Things. With the exponentially increasing number of connected wireless devices in the order of 100 billion, it has become crucial that researchers develop efficient resource management techniques to meet the 5 th Generation (5G) quality of service (QoS) requirements. Recently, several research challenges including the low modulation data rates, energy-expensive channel coding techniques, and the fast-growing number of connected devices have been identified as some of the main issues encountered in the design and deployment of NB-IoT systems. In addition, several techniques have emerged in the literature to resolve some of these challenges of NB-IoT systems. However, the research activities towards the enhancement of the NB-IoT resource management are yet to continue in the next half-decade before, high data rates, energyefficient, and scalable NB-IoT specifications can be released for the standardisation and commercialisation. Considering the limited number of existing surveys of such technical enhancement approaches in a broader perspective (i.e. energy efficiency, data rate performance and scalability) and also the non-existence, to the best of our knowledge, of a comparative survey, this paper seeks to elaborate, describe and compare the performances of such resources management approaches. Of the multiple NB-IoT resources, the focus of this paper is on the data rate, energy efficiency, and scalability enhancement schemes that have been proposed for the last three years. The contribution of the paper lies in the analysis, synthesis, comparison and summarised alignments of some of the major existing schemes towards identifying challenges faced by the NB-IoT development. Finally, this work seeks to identify research challenges, open questions, and opportunities that could arise from the existing techniques analysed. INDEX TERMS Data rates, energy efficient, challenges, narrowband IoT (NB-IoT), opportunities, resources, scalability, reliability.
International Journal on AdHoc Networking Systems, 2018
In recent times, the use of Smart antennas (SA) in wireless communications has greatly increased;... more In recent times, the use of Smart antennas (SA) in wireless communications has greatly increased; this is because of their ability to increase the coverage and capacity of a network. There are two main functions which SAs perform: direction of arrival (DOA) and beamforming. SAs are able to produce the main beams towards a desired user and at the same time, form nulls in the direction of interfering signals. They are able to achieve this by the use of beamforming algorithms. The performance of an enhanced Recursive Least Squares (RLS) algorithm which takes into account an enhanced gain factor of the RLS algorithm is evaluated in this paper for adaptive array beamforming. Simulation results show that the enhanced RLS reduces mean square error (MSE), smoothens filter output improves SNR;thus, improving the gain of the RLS algorithm. The result of this work will lead to an increased range of beamforming and directivity of the smart antenna over a long range communication network.
Role Based Access Control (RBAC) is one of the most used models in designing and implementation o... more Role Based Access Control (RBAC) is one of the most used models in designing and implementation of security policies in large networking systems. The classical model doesn't consider temporal aspects which are so important in such policies. Temporal RBAC (TRBAC) is proposed to deal with these aspects. Although the elegance of these models, design a security policy remains a challenge. One is obliged to prove the consistency and the correctness of the policy. Using formal verification allows proving that the designed policy is consistent. In this paper 1 , we present a formal modelling/analysis approach for TRBAC policies. We use Timed Colored Petri Nets to model the TRBAC policy, and then CPN-tool is used to analyze the generated models. The analysis allows proving many important properties about the TRBAC security policy.
Computational and mathematical methods in medicine, 2018
Graph cut segmentation provides a platform to analyze images through a global segmentation strate... more Graph cut segmentation provides a platform to analyze images through a global segmentation strategy, and as a result of this, it has gained a wider acceptability in many interactive and automatic segmentation fields of application, such as the medical field. The graph cut energy function has a parameter that is tuned to ensure that the output is neither oversegmented (shrink bias) nor undersegmented. Models have been proposed in literature towards the improvement of graph cut segmentation, in the context of interactive and automatic cell segmentation. Along this line of research, the graph cut parameter has been leveraged, while in some instances, it has been ignored. Therefore, in this work, the relevance of graph cut parameter on both interactive and automatic cell segmentation is investigated. Statistical analysis, based on F1 score, of three publicly available datasets of cells, suggests that the graph cut parameter plays a significant role in improving the segmentation accuracy...
Identification of wheelchair user steering behaviour within indoor environments
2015 IEEE International Conference on Robotics and Biomimetics (ROBIO), 2015
The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to t... more The wide acceptance of wheelchairs in the society may be associated to their simplicity, and to the important mobility ease they provide to people with disability. Nonetheless, users with extreme mobility impairments still experience some cognitive and physical steering challenges that limit their capacity to navigate even simple environments. Assistive wheelchairs with functionalities to enable customisation of user handicap are therefore still required. The diversity of user disabilities and needs, and the corresponding assistive measures, necessitate proper understanding of the user. Modelling and integration of user driving behaviour into the control loop in order to monitor user inputs, and execute necessary corrective steps in troublesome situations, may just be one way of providing the assistance that corresponds to needs of the user. This paper attempts to identify the steering behaviour of an individual wheelchair user in a normal living room environment. The preliminary navigation experiments required to obtain the steering data are performed in a virtual world on an augmented wheelchair platform, and the participant is observed to exhibit expected navigational behaviours. Least square method is considered in the estimation of model parameters for the non-linear steering model with interesting regression analysis outcome.
International Journal of Applied Mathematics and Computer Science, 2012
Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations d... more Wireless Backbone Networks (WBNs) equipped with Multi-Radio Multi-Channel (MRMC) configurations do experience power control problems such as the inter-channel and co-channel interference, high energy consumption at multiple queues and unscalable network connectivity. Such network problems can be conveniently modelled using the theory of queue perturbation in the multiple queue systems and also as a weak coupling in a multiple channel wireless network. Consequently, this paper proposes a queue perturbation and weakly coupled based power control approach forWBNs. The ultimate objectives are to increase energy efficiency and the overall network capacity. In order to achieve this objective, a Markov chain model is first presented to describe the behaviour of the steady state probability distribution of the queue energy and buffer states. The singular perturbation parameter is approximated from the coefficients of the Taylor series expansion of the probability distribution. The impact of...
Non Destructive Sensing of Food Materials using Fuzzy c-means Clustering