286 research outputs found
ФОРМУВАННЯ У МОЛОДШИХ ШКОЛЯРІВ УМІННЯ РОЗВ’ЯЗУВАТИ СЮЖЕТНІ МАТЕМАТИЧНІ ЗАДАЧІ
No full textThe problem of forming junior pupils\u27 skills to do topic sums is considered in the article
МЕТОДИЧНА СИСТЕМА НАВЧАННЯ РОЗВ’ЯЗУВАННЯ ЗАДАЧ
No full textIn the article of Skvortsovoy Svetlany “Methodical system of studies of untiing of tasks”. The aims of with plots tasks are certain in a course mathematics of primary school, maintenance of task material and programmatic minimum is shortly described certain the basic method of studies of untiing of tasks, as the special systems of educational tasks, organizational forms and facilities of studies are reflected, among which a certain place belongs to the design as text of task so process of its untiing
Enhanced electrical and optical properties of room temperature deposited Aluminium doped Zinc Oxide (AZO) thin films by excimer laser annealing
No full textHigh quality transparent conductive oxides (TCOs) often require a high thermal budget fabrication process. In this study, Excimer Laser Annealing (ELA) at a wavelength of 248 nm has been explored as a processing mechanism to facilitate low thermal budget fabrication of high quality aluminium doped zinc oxide (AZO) thin films. 180 nm thick AZO films were prepared by radio frequency magnetron sputtering at room temperature on fused silica substrates. The effects of the applied RF power and the sputtering pressure on the outcome of ELA at different laser energy densities and number of pulses have been investigated. AZO films deposited with no intentional heating at 180 W, and at 2 mTorr of 0.2% oxygen in argon were selected as the optimum as-deposited films in this work, with a resistivity of 1×10−3 Ω.cm, and an average visible transmission of 85%. ELA was found to result in noticeably reduced resistivity of 5×10−4 Ω.cm, and enhancing the average visible transmission to 90% when AZO is processed with 5 pulses at 125 mJ/cm2. Therefore, the combination of RF magnetron sputtering and ELA, both low thermal budget and scalable techniques, can provide a viable fabrication route of high quality AZO films for use as transparent electrodes
Computing in Large-Scale Dynamic Systems
No full textSoftware applications developed for large-scale systems have always been difficult to de- velop due to problems caused by the large number of computing devices involved. Above a certain network size (roughly one hundred), necessary services such as code updating, topol- ogy discovery and data dissemination are challenging to operate and thus difficult to design and implement. This is caused by the sheer size of the system in terms of number of devices that have to be managed. Practical aspects such as harsh and unpredictable deployment con- ditions and varying system properties such as topology dynamics due to device mobility and variations of the communication links cannot be ignored. In this thesis, we investigated how distributed computing techniques can be used for detecting some of the specific properties of large-scale dynamic systems. Additionally, novel online algorithms have been presented for detecting some of the detrimental effects such as unpredictable topology dynamics and random link and device failures. We started our research by focusing on ways to cope with topology dynamics caused by device mobility and corresponding techniques for managing the creation of overlays in mobile networks. The ASH clustering algorithm introduced in Chapter 2 copes well with device mobil- ity and is remarkably resilient to topology dynamics in general. It is able to create quasi-static overlays while the underlying devices are mobile. Unlike traditional clustering schemes, ASH does not use device location, and the computation is based solely on 1-hop information. By making use of local interactions, it benefits from the so-called emergent behaviour in complex networked systems to achieve self-stabilisation. The second challenge that we addressed in Chapter 3 was the design of a distributed es- timator for the aggregate quality of the communication links in a large-scale network. Data dissemination protocols employed in wireless systems can use this information in order to ad- just various application behaviours. We have introduced an algorithm, named LossEstimate, for run-time estimation of the aggregate number of communication failures present in a re- gion or the entire system. Our approach has the advantage of being completely decentralised - each device computes an estimate of the number of errors using a localised, gossip-based algo- rithm. The devised method follows changes in the mean value of the communication failures over time. The algorithm has an important building block - a mechanism called DiffusionRe- set - that is able to track dynamic system properties by continuously re-starting the gossiping process. In Chapter 4 we addressed the problem of computing the number of nodes that are actively entering and exiting a large-scale system, also called churn level. A method that solves this problem can be utilised in traffic monitoring applications. At its core, it uses the DiffusionReset mechanism for being able to offer an estimate at every device in realtime. The current state of the art offers a limited set of alternatives. ChurnDetect is able to cope well also with the effects of device mobility such as dynamic, multi-hop topologies characterised by frequent device and communication failures. The next problem we addressed in Chapter 5 was the detection of a phenomenon called FlashCrowd in peer-to-peer systems. Content-delivery applications benefit from having an on- line estimation of such a phenomena. We specifically focus on the problem of online detection with an algorithm called FlashDetect. To the best of our knowledge, this is one of the first on- line methods for detecting this phenomenon. We use again the DiffusionReset mechanism and a special protocol initialisation for the peers that are entering the system - the initial gossiping values are set to 0. The remarkable property of FlashDetect is that peers do not need to ad- vertise their departure. This makes the algorithm very robust to various device and application failures, unlike competing methods. For networked embedded systems, the ultimate validation of distributed algorithms on real hardware is always preferable. In order to check our algorithms and open-up the possibility for non-IT specialists to test ideas, in Chapter 6 we introduced a software tool chain that enables fast prototyping of algorithms on large-scale systems, by abstracting away from the underlying technological complexity related to communication protocols, programming languages, operat- ing systems, virtual machines and hardware platforms. We made use of the Spatial Computing paradigm to map interactive design applications and distributed algorithms in general onto em- bedded systems middleware. By abstracting away from low-level implementation details of advanced communication protocols and numerous algorithmic building blocks, we offer the possibility for rapid prototyping of ideas. Spatial eLua accelerates thus the work of algorithm designers as well as non-IT specialists interested in making use of the latest technologies in interactive design installations. Our work has lead us to the conclusion that managing large-scale systems is possible via feedback provided by distributed algorithms that estimate various system properties. Ran- domised communication strategies such as gossip-based protocols are very well suited for cre- ating online estimators while being robust to failures. With the help of spatial computing, ideas can be tested and validated easily on various embedded platforms even by non-IT specialists. Even though we made steps in this direction, further effort is required for testing other novel algorithms and their corresponding spatial computing constructs.Embedded SoftwareElectrical Engineering, Mathematics and Computer Scienc
Network-based bootloader for distributed embedded systems applications
No full textThis thesis describes the design, implementation and deployment of a network-based bootloader for distributed embedded systems applications. The bootloader is based NXP's LPC1769 microcontroller containing the ARM Cortex-M3 processor. The CAN bus is used as the network's physical layer. Due to the modular design of the bootloader, easily switching to different technologies is possible. Up to the day of publishing of this thesis, flashing of 88 microcontrollers with a 180kB binary takes 1.5 minutes, while adding new microcontrollers does not add time.Embedded SoftwareSoftware TechnologyElectrical Engineering, Mathematics and Computer Scienc
Wireless Sensor Platform for Sporting Applications
No full textWith Wireless Sensors widely used in various domains like home automation, industrial monitoring there is a market urge to deploy the wireless sensors in sporting applications. By deploying wireless sensors in sports, various dimensions of use-case scenarios become obvious which include monitoring sports players to help assess their fitness levels during training sessions and during play, enhance game strategy and provide TV broadcasters with lucrative statistics for the audience. As a first step to realize these use-cases, a platform to create such applications is needed to rapidly prototype devices as a proof of concept. However, to monitor professional sports players and to help make scientific analysis, a deluge of information is needed with less error margin. In this thesis, a wireless sensor platform is designed and developed, customized for creating prototypes of nodes for the sports players. Multiple gateways can be used along the boundary of the play-field to cover the entire playfield and with the mobile sensor nodes making hand-off between the gateways based on their proximity. A time-sharing mechanism is used by the nodes to gain access to the channel and is centralized at the gateway. The gateway provides authentication to which sensor node can transmit data in a round-robin manner. Experimental results show that the packet losses are around 1% with varying cases explaining that only one node communicate with the gateway at any point of time. One of the major drawbacks of such time-slotted protocols is the latency due to the failed nodes and in this protocol a mechanism is devised to mitigate this latency. The net data-rate is also enhanced by transmitting multiple packets in a time-compacted slot without linearly increasing the slot-width.Embedded SoftwareComputer ScienceElectrical Engineering, Mathematics and Computer Scienc
Automatic Discovery of Distributed Algorithms for Large-Scale Systems
No full textIn recent years, large-scale systems have become mainstream at a very high pace. Typical examples of large-scale systems are MANETs, Wireless Sensor Networks, Pervasive Computing, Swarm Robotics, etc. These systems distinguish them- selves by the large number of devices they embody, and emergent behaviors they exhibit: Behavior that is globally perceivable, but that is made up of only local interactions of the system elements. Because of the vast amount of devices that make up a large-scale system, it is infeasible to exhibit centralized control. As an alternative, we need to leverage distributed algorithms to create and control emergent behaviors for the global goal we want the system to exhibit. Since there is no linear mapping from local interactions to global behavior, we present a global-to-local compiler to automatically generate these distributed algorithms for large-scale systems. By using Genetic Programming to combine already known building blocks from other distributed algorithms, we provide a high-level, goal-driven framework for algorithm designers to design distributed algorithms. Evaluation shows that the framework we present is indeed a valuable tool for designing distributed algorithms for large-scale systems. Improving the develop- ment speed, allowing the designer to be agnostic to the underlying details, but nevertheless providing a flexible interface, to acquire the algorithm desired.Computer ScienceEmbedded SoftwareElectrical Engineering, Mathematics and Computer Scienc
Corrigendum to “Mild cognitive impairment due to Alzheimer disease: Contemporary approaches to diagnostics and pharmacological intervention” [Pharmacol. Res. 129 (2018) 216–226] (S1043661817309374) (10.1016/j.phrs.2017.11.021))
No full textThe authors regret that the text published was missing the following information:the e mail address of Dr S.O. Bachurin, a corresponding author, which is [email protected]; the affiliation of Dr G. Aliev is also *GALLY International Biomedical Research Consulting LLC, 7733 Louis Pasteur Drive, #330, San Antonio, TX, 78229, USA. The authors also state that they have no conflict of interest and that the research was supported in part by RSF project #14-23-00160P and the scientific projects of IPAC (topics 48.8. and 48.9). Authors’ also very grateful for the animal facilities were provided by Center for preclinical trials of IPAC RAS. The authors would like to apologise for any inconvenience caused. Conflict of interest The authors confirm that article content has no conflict of interest. © 2018 Elsevier LtdUniversidad Autónoma de Chil
DelftVM
No full textFinal report about DelftVM.Distrubuted SystemsElectrical Engineering, Mathematics and Computer Scienc
Application of automotive alternators in small wind turbines
No full textSmall wind turbines have been in existence for several years but it seems they are not used where they are needed the most-distant off grid communities in developing countries. Cost and maintenance have been attributed to be reasons for this. One of its expensive constituents is its generator. The automotive alternator is considered as an alternative for generators in small wind turbines. In this project work, an off-the-shelf recycled automotive alternator is experimentally parameterized and modeled with an assumed small wind turbine. The wind turbine’s characteristics have been designed to match the power requirements of the alternator. The dynamic response of the alternator to wind speed variations is modeled and the effect of turbine blades’ inertia on the generator speed and by extension on the wind turbine’s performance coefficient indicates the need for a speed control mechanism to attain turbine optimal power operation. The speed control serves the purpose of tracking the turbine’s maximum power characteristics. Other requirements for adaptation of the alternator are investigated and discussed in this thesis.Electrical power processingElectrical Power EngineeringElectrical Engineering, Mathematics and Computer Scienc
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