29 research outputs found

    A study on stryi-icnos potatorum and pisum sativum as natural coagulants for meat food processing wastewater

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    Slow maintained load test is widely used by contractors in Malaysia to ensure the driven pile could accommodate the design load of the structure. Slow maintained load test is a test to determine load-settlement curve and pile capacity for a period of time using conventional load test. Conventional static pile load test equipment is large in size thus making it heavier and takes a long time to install. In addition, it consumes a lot of space which causes congestion at construction sites. Therefore, the objective of this thesis is to conduct a conventional load test by replacing the pile kentledge load with anchorage and reaction pile. Preparations of ten designs comprising six commercial designs were reviewed. In addition, four proposed designs were suggested for the setup. Final design was produced based on its safety factors and criteria referred via literature review. The test frame consists of reaction frame with four reaction helical pile with two helixes per reaction pile. The deformation shapes, safety factor, stress, and strain of the design and finite element of the model has been analysed with the use of SolidWorks and Pia.xis 30 software. SolidWorks software emphasizes on the model load-deflection relationship while Plaxis 30 ensures a correlation of reaction between pile uplift force and soil. Then, the model was tested on site to determine the relationship between physical load­deflection and pile-soil uplift force. The results of uplift force and displacement for numerical and physical test were nearly identical which increment of load­displacement graph pattern. The higher the uplift force, the higher the displacement obtained. In conclusion, the result obtained and the design may be considered as a guideline for future application of sustainable slow maintained pile load test

    A critical analysis of research potential, challenges and future directives in industrial wireless sensor networks

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    In recent years, Industrial Wireless Sensor Networks (IWSNs) have emerged as an important research theme with applications spanning a wide range of industries including automation, monitoring, process control, feedback systems and automotive. Wide scope of IWSNs applications ranging from small production units, large oil and gas industries to nuclear fission control, enables a fast-paced research in this field. Though IWSNs offer advantages of low cost, flexibility, scalability, self-healing, easy deployment and reformation, yet they pose certain limitations on available potential and introduce challenges on multiple fronts due to their susceptibility to highly complex and uncertain industrial environments. In this paper a detailed discussion on design objectives, challenges and solutions, for IWSNs, are presented. A careful evaluation of industrial systems, deadlines and possible hazards in industrial atmosphere are discussed. The paper also presents a thorough review of the existing standards and industrial protocols and gives a critical evaluation of potential of these standards and protocols along with a detailed discussion on available hardware platforms, specific industrial energy harvesting techniques and their capabilities. The paper lists main service providers for IWSNs solutions and gives insight of future trends and research gaps in the field of IWSNs

    Wireless Technologies for IoT in Smart Cities

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    [EN] As cities continue to grow, numerous initiatives for Smart Cities are being conducted. The concept of Smart City encompasses several concepts being governance, economy, management, infrastructure, technology and people. This means that a Smart City can have different communication needs. Wireless technologies such as WiFi, ZigBee, Bluetooth, WiMax, 4G or LTE (Long Term Evolution) have presented themselves as solutions to the communication needs of Smart City initiatives. However, as most of them employ unlicensed bands, interference and coexistence problems are increasing. In this paper, the wireless technologies available nowadays for IoT (Internet of Things) in Smart Cities are presented. Our contribution is a review of wireless technologies, their comparison and the problems that difficult coexistence among them. In order to do so, the characteristics and adequacy of wireless technologies to each domain are considered. The problems derived of over-crowded unlicensed spectrum and coexistence difficulties among each technology are discussed as well. Finally, power consumption concerns are addressed.García-García, L.; Jimenez, JM.; Abdullah, MTA.; Lloret, J. (2018). Wireless Technologies for IoT in Smart Cities. Network Protocols and Algorithms. 10(1):23-64. doi:10.5296/npa.v10i1.12798S236410

    Performance of a Busy-Tone Approach on 802.11 Wireless Network

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    The big evolution of modem applications in the wireless networks domain as the wireless videos remote access, big files transfer, streaming and downloading high definition videos etc, has led to using the mmWave technology (60 GHz for example) that represents an important solution for the se applications because of the advantages presented by this frequency band such as the high data rate transmission up to multi gigabits, also the large bandwidth that goes up to 7 GHz. The use of the mm Wave technology requires a MAC protocol which ensures the channel sharing between users in a multi-node network, with directional antennas that increase spatial reuse and cover a wider area compared to the omnidirecti on al antennas. Many access method approaches were used in order to resolve these problems, for instance, the methods that use a signaling channel, then methods that exploit directional antennas with directional frames, and those using beacons and many others .... In our project, we worked on the adaptation of the 'Busy - Tone' method using the 802.11 ad protocol with directional antennas in addition to a coordination between 2.4 GHz and 60 GHz. This method offers a big solution to resolve the collisions of data and control packets that affect and reduce the network capacity and lead to data loss. Simulation results showed the efficiency of this model by reducing collisions caused by hidden terminais, therefore, enhancing the performance of the network in terms oftransmission delay, retransmission attempts and throughput. L'évolution des applications modernes dans le domaine des réseaux sans fils tel que 1 'accès à distance des vidéos sans fils, le transfert des gros fichiers, flux des vidéos à haute définition etc .... nécessite l'utilisation de la bande 60 GHz qui présente une solution très importante pour ces applications grâce aux avantages que présente cette bande tel que le taux de transmission des données qui atteint quelques Gigabits, et aussi grâce à la bande passante du canal qui est environ 7 GHz. L'utilisation de cette bande de fréquence nécessite un protocole MAC qui assure le partage de canal entre les utilisateurs dans un réseau multi-noeuds. Ce protocole doit tenir compte les problèmes et les défis qui se produisent grâce à l'utilisation de la bande 60 GHz, tel que les problèmes des terminales cachées et exposées Dans ce projet on a proposé une méthode qui se base sur l'adaptation de protocole 802.llad avec la méthode 'Busy-Tone 'parce qu'elle représente la solution la plus efficace pour résoudre les problèmes des collisions des paquets de donnés et les paquets de contrôle qui sont causés normalement par la présence des terminales cachées et exposées. L'approche proposée consiste aussi à utiliser les antennes directives qm augmentent la réutilisation spatiale et couvre une portée plus grande par rapport à l'antenne omnidirectionnelle. Ces antennes ont été utilisées à côté des antennes omnidirectionnelles avec une coordination entre les deux, alors les antennes omnidirectionnelles sont utilisées pour envoyer les signaux 'Busy-Tone ' tandis que les antennes directives sont utilisées pour envoyer les paquets de données. Les résultats de la simulation ont montré une amélioration au niveau de la performance du réseau en terme du débit, du délai et les essaies de retransmission en comparant avec le standard 801.11ad. La mise en oeuvre est effectuée dans le logiciel Matlab/Simulink. Les paramètres utilisés dans les simulations sont des valeurs typiques des centrales existantes ou prises dans la littérature. La conformité avec la littérature est réalisée grâce à une validation croisée progressive de chaque sous-ensemble et du système globa

    A real-time packet scheduling system for a 6LoWPAN industrial application

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    Nowadays, the industrial Wireless Sensor Networks (WSN) are crucial for the monitoring and control of the modern smart factory floor that is relying on them for critical applications and tasks that were performed by wired systems in the past. For this reason, it is required that the transmission mechanisms of wireless sensor networks are efficient and robust and that they guarantee realtime responses with low data losses. Furthermore, it is required that they utilize common networking standards, such as the Internet Protocol (IP), that provides interoperability with already existing infrastructures and offers widely tested security and transmission control protocols. The theoretical part of this document focuses on the description of the current panorama of the industrial WSN, its applications, design challenges and standardizations. It describes the 6LoWPAN standard and the wireless transmission technology that it uses for its lower layers, the IEEE 802.15.4 protocol. Later, it describes the principles behind the wireless scheduling, a state-of-the-art in the IEEE 802.15.4 scheduled channel access and the features of the most used operating systems for WSN. The practical part presents the real-time packet scheduling system for a 6LoWPAN industrial application proposed by this thesis work that adapts the HSDPA scheduling mechanisms to the IEEE 802.15.4 beacon-enabled mode. The system implemented manages the channel access by allocating Guaranteed Time Slots to sensor nodes according to the priority given by three scheduling algorithms that can be selected according to the traffic condition of the network. The system proposed was programmed using Contiki OS. It is based on the eSONIA 6LoWPAN firmware developed for the European Research Project and it was deployed on the FAST WSN for testing. The results, discussion and conclusions are documented at the final sections of this part

    Five Facets of 6G: Research Challenges and Opportunities

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    Whilst the fifth-generation (5G) systems are being rolled out across the globe, researchers have turned their attention to the exploration of radical next-generation solutions. At this early evolutionary stage we survey five main research facets of this field, namely {\em Facet~1: next-generation architectures, spectrum and services, Facet~2: next-generation networking, Facet~3: Internet of Things (IoT), Facet~4: wireless positioning and sensing, as well as Facet~5: applications of deep learning in 6G networks.} In this paper, we have provided a critical appraisal of the literature of promising techniques ranging from the associated architectures, networking, applications as well as designs. We have portrayed a plethora of heterogeneous architectures relying on cooperative hybrid networks supported by diverse access and transmission mechanisms. The vulnerabilities of these techniques are also addressed and carefully considered for highlighting the most of promising future research directions. Additionally, we have listed a rich suite of learning-driven optimization techniques. We conclude by observing the evolutionary paradigm-shift that has taken place from pure single-component bandwidth-efficiency, power-efficiency or delay-optimization towards multi-component designs, as exemplified by the twin-component ultra-reliable low-latency mode of the 5G system. We advocate a further evolutionary step towards multi-component Pareto optimization, which requires the exploration of the entire Pareto front of all optiomal solutions, where none of the components of the objective function may be improved without degrading at least one of the other components
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