310 research outputs found

    An enhanced evolutionary algorithm for requested coverage in wireless sensor networks

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    Wireless sensor nodes with specific and new sensing capabilities and application requirements have affected the behaviour of wireless sensor networks and created problems. Placement of the nodes in an application area is a wellknown problem in the field. In addition, high per-node cost as well as need to produce a requested coverage and guaranteed connectivity features is a must in some applications. Conventional deployments and methods of modelling the behaviour of coverage and connectivity cannot satisfy the application needs and increase the network lifetime. Thus, the research designed and developed an effective node deployment evaluation parameter, produced a more efficient node deployment algorithm to reduce cost, and proposed an evolutionary algorithm to increase network lifetime while optimising deployment cost in relation to the requested coverage scheme. This research presents Accumulative Path Reception Rate (APRR) as a new method to evaluate node connectivity in a network. APRR, a node deployment evaluation parameter was used as the quality of routing path from a sensing node to sink node to evaluate the quality of a network deployment strategy. Simulation results showed that the behaviour of the network is close to the prediction of the APRR. Besides that, a discrete imperialist competitive algorithm, an extension of the Imperialist Competitive Algorithm (ICA) evolutionary algorithm was used to produce a network deployment plan according to the requested event detection probability with a more efficient APRR. It was used to reduce deployment cost in comparison to the use of Multi-Objective Evolutionary Algorithm (MOEA) and Multi-Objective Deployment Algorithm (MODA) algorithms. Finally, a Repulsion Force and Bottleneck Handling (RFBH) evolutionary-based algorithm was proposed to prepare a higher APRR and increase network lifetime as well as reduce deployment cost. Experimental results from simulations showed that the lifetime and communication quality of the output network strategies have proven the accuracy of the RFBH algorithm performance

    Can We `Feel' the Temperature of Knowledge? Modelling Scientific Popularity Dynamics via Thermodynamics

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    Just like everything in the nature, scientific topics flourish and perish. While existing literature well captures article's life-cycle via citation patterns, little is known about how scientific popularity and impact evolves for a specific topic. It would be most intuitive if we could `feel' topic's activity just as we perceive the weather by temperature. Here, we conceive knowledge temperature to quantify topic overall popularity and impact through citation network dynamics. Knowledge temperature includes 2 parts. One part depicts lasting impact by assessing knowledge accumulation with an analogy between topic evolution and isobaric expansion. The other part gauges temporal changes in knowledge structure, an embodiment of short-term popularity, through the rate of entropy change with internal energy, 2 thermodynamic variables approximated via node degree and edge number. Our analysis of representative topics with size ranging from 1000 to over 30000 articles reveals that the key to flourishing is topics' ability in accumulating useful information for future knowledge generation. Topics particularly experience temperature surges when their knowledge structure is altered by influential articles. The spike is especially obvious when there appears a single non-trivial novel research focus or merging in topic structure. Overall, knowledge temperature manifests topics' distinct evolutionary cycles

    Innovative Technologies and Services for Smart Cities

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    A smart city is a modern technology-driven urban area which uses sensing devices, information, and communication technology connected to the internet of things (IoTs) for the optimum and efficient utilization of infrastructures and services with the goal of improving the living conditions of citizens. Increasing populations, lower budgets, limited resources, and compatibility of the upgraded technologies are some of the few problems affecting the implementation of smart cities. Hence, there is continuous advancement regarding technologies for the implementation of smart cities. The aim of this Special Issue is to report on the design and development of integrated/smart sensors, a universal interfacing platform, along with the IoT framework, extending it to next-generation communication networks for monitoring parameters of interest with the goal of achieving smart cities. The proposed universal interfacing platform with the IoT framework will solve many challenging issues and significantly boost the growth of IoT-related applications, not just in the environmental monitoring domain but in the other key areas, such as smart home, assistive technology for the elderly care, smart city with smart waste management, smart E-metering, smart water supply, intelligent traffic control, smart grid, remote healthcare applications, etc., signifying benefits for all countries

    Enhancing wireless sensor networks functionalities

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     The main objective of this thesis is to develop solutions for the existing research problems in wireless sensor networks that negatively influence their performances. To achieve that four main research gaps from collecting, aggregating and transferring data with considering different deployment methods of sensor nodes were addressed

    Carbon Electronics: Nano-carbons for the development of radiation sensors, image intensifiers and medical sensors

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    Carbon nano-materials, both in sp2 (graphene like) and sp3 (diamond) con- figurations are renowned for their unmatched novel properties. In particular, its extremely high electrical conductivity, radiation hardness and electron amplification are widely coveted. This investigation aims to capitalise on the above by developing blood pressure sensors, radiation detectors and signal amplifiers from the said carbon nano-materials. Namely, carbon nanotubes (sp2 carbon) were integrated into a polymer host to form a composite. Where it has been found that by altering the surface functionalisations of carbon nanotubes (non-functionalised, -OH and -COOH) the electrical resistance of the composite could vary drastically as much as 1012Ω to 107Ω. This brings potential benefits in reduced production costs, reduced environmental damage and wider technological adoption of carbon composite based devices. Carbon nanotubes were then encased in a soft and biocompatible host, polydimethylsiloxane (PDMS), in order to fabricate an in vivo blood pressure sensor, exploiting its piezo-resistivity. Results have shown a successful and adequate degree of piezo-resistivity (109Ω to 106Ω for 2D and 4kΩ to 750kΩ for 3D compression) at the desired size-scale of 200Β΅m and 4mm respectively. This is a size equivalent to that of the diameter of blood vessels in question. However, further investigation into re-miniaturisation is recommended for future works. Diamond (sp3 carbon), on the other hand, was used as a longlasting solution to neutron detection for a Trident nuclear submarine, HMS Artful. The investigation entailed a three-phase process of: Ξ±-particle detection, LiF conversion layer addition and neutron detection. Results has shown clear signs of Ξ±-particle and neutron detection with a device efficiency of 32.3% and 48.3% respectively, as well as Ξ³-ray transparency and sufficient Q-factor between the signal peak and detection peak. Diamond was also used as a signal amplifier that has application as an image intensifier for night-vision goggles where it was found thatby altering the surface functionalisation of nano-diamonds (H, O and LiO) one could enhance or suppress the secondary electron emission effect. Additionally, it was found that the electrical gain from the said secondary electron emission has a strong dependence on the crystal structure of the diamond layer and in turn its growth conditions. Most notably, LiO functional group was found to be more resilient towards higher temperatures (800oC) and electron bombardments but fell short in the amount of electrical gain it generated in comparison to conventional functionalisations such as H. However, the X-ray photoelectron spectroscopy (XPS) results suggest that this may be due to the lack of LiO coverage and upon further investigation, LiO may potentially bode better if not surpass the gain performance of H

    μ—°μ„± 및 μƒμž¬ν‘μˆ˜μ„± μ „μžμ†Œμžμš© λΉ„νœ˜λ°œμ„± λ©”λͺ¨λ¦¬ μ†Œμžμ™€ μ§‘μ μ„Όμ„œ κ΅¬ν˜„

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    ν•™μœ„λ…Όλ¬Έ (박사)-- μ„œμšΈλŒ€ν•™κ΅ λŒ€ν•™μ› : 화학생물곡학뢀, 2015. 8. κΉ€λŒ€ν˜•.Over years, major advances in healthcare have been made through research in the fields of nanomaterials and microelectronics technologies. However, the mechanical and geometrical constraints inherent in the standard forms of rigid electronics have imposed challanges of unique integration and therapeutic delivery in non-invasive and minimally invasive medical devices. Here, we describe two types of multifunctional electronic systems. The first type is wearable-on-the-skin systems that address the challenges via monolithic integration of nanomembranes fabricated by top-down approach, nanotubes and nanoparticles assembled by bottom-up strategies, and stretchable electronics on tissue-like polymeric substrate. The system consists of physiological sensors, non-volatile memory, logic gates, and drug-release actuators. Some quantitative analyses on the operation of each electronics, mechanics, heat-transfer, and drug-diffusion characteristic validated their system-level multi-functionalities. The second type is a bioresorbable electronic stent with drug-infused functionalized nanoparticles that takes flow sensing, temperature monitoring, data storage, wireless power/data transmission, inflammation suppression, localized drug delivery, and photothermal therapy. In vivo and ex vivo animal experiments as well as in vitro cell researches demonstrate its unrecognized potential for bioresorbable electronic implants coupled with bioinert therapeutic nanoparticles in the endovascular system. As demonstrations of these technologies, we herein highlight two representative examples of multifunctional systems in order of increasing degree of invasiveness: electronically enabled wearable patch and endovascular electronic stent that incorporate onboard physiological monitoring, data storage, and therapy under moist and mechanically rigorous conditions.Contents Abstract Chapter 1. Introduction 1.1 Organic flexible and wearable electronics.................................................. 1 1.2 Inorganic flexible and wearable electronics............................................... 14 1.3 Flexible non-volatile memory devices.......................................................... 25 1.4 Bioresorbable materials and devices........................................................... 34 References Chapter 2. Multifunctional wearable devices for diagnosis and therapy of movement disorders 2.1 Introduction ................................................................................. 45 2.2 Experimental Section ......................................................................... 49 2.3 Result and Discussion ........................................................................ 65 2.4 Conclusion ................................................................................... 95 References Chapter 3. Stretchable Carbon Nanotube Charge-Trap Floating-Gate Memory and Logic Devices for Wearable Electronics 3.1 Introduction ................................................................................ 101 3.2 Experimental Section ........................................................................ 104 3.3 Result and Discussion ....................................................................... 107 3.4 Conclusion .................................................................................. 138 References Chapter 4. Bioresorbable Electronic Stent Integrated with Therapeutic Nanoparticles for Endovascular Diseases 4.1 Introduction ................................................................................ 148 4.2 Experimental Section ........................................................................ 151 4.3 Result and Discussion ....................................................................... 173 4.4 Conclusion .................................................................................. 219 References κ΅­λ¬Έ 초둝 (Abstract in Korean) .................................................................. 230Docto

    Carbon Nanotubes

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    Since their discovery in 1991, carbon nanotubes have been considered as one of the most promising materials for a wide range of applications, in virtue of their outstanding properties. During the last two decades, both single-walled and multi-walled CNTs probably represented the hottest research topic concerning materials science, equally from a fundamental and from an applicative point of view. There is a prevailing opinion among the research community that CNTs are now ready for application in everyday world. This book provides an (obviously not exhaustive) overview on some of the amazing possible applications of CNT-based materials in the near future

    Advances in Computer Science and Engineering

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    The book Advances in Computer Science and Engineering constitutes the revised selection of 23 chapters written by scientists and researchers from all over the world. The chapters cover topics in the scientific fields of Applied Computing Techniques, Innovations in Mechanical Engineering, Electrical Engineering and Applications and Advances in Applied Modeling

    High-Performance Modelling and Simulation for Big Data Applications

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    This open access book was prepared as a Final Publication of the COST Action IC1406 β€œHigh-Performance Modelling and Simulation for Big Data Applications (cHiPSet)β€œ project. Long considered important pillars of the scientific method, Modelling and Simulation have evolved from traditional discrete numerical methods to complex data-intensive continuous analytical optimisations. Resolution, scale, and accuracy have become essential to predict and analyse natural and complex systems in science and engineering. When their level of abstraction raises to have a better discernment of the domain at hand, their representation gets increasingly demanding for computational and data resources. On the other hand, High Performance Computing typically entails the effective use of parallel and distributed processing units coupled with efficient storage, communication and visualisation systems to underpin complex data-intensive applications in distinct scientific and technical domains. It is then arguably required to have a seamless interaction of High Performance Computing with Modelling and Simulation in order to store, compute, analyse, and visualise large data sets in science and engineering. Funded by the European Commission, cHiPSet has provided a dynamic trans-European forum for their members and distinguished guests to openly discuss novel perspectives and topics of interests for these two communities. This cHiPSet compendium presents a set of selected case studies related to healthcare, biological data, computational advertising, multimedia, finance, bioinformatics, and telecommunications
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