49 research outputs found

    Accurate acoustic ranging system using android smartphones

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    ACCURATE ACOUSTIC RANGING SYSTEM USING ANDROID SMARTPHONES By Mohammadbagher Fotouhi, Master of Science A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science at Virginia Commonwealth University Virginia Commonwealth University 2017 Major Director: Dr. Ruixin Niu, Associate Professor of Department of Electrical and Computer Engineering In this thesis, we present the design, implementation, and evaluation of an android ranging system, a high-accuracy acoustic-based ranging system which allows two android mobile phones to learn their physical distance from each other. In this system we propose a practical solution for accurate ranging based on acoustic communication between speakers and microphones on two smartphones. Using the audible-band acoustic signal with the Wi-Fi assistance without the sound disturbance is promising for large deployment. Our method is a pure software-based solution and uses only the most basic set of commodity hardware: a speaker, a microphone, and Wi-Fi communication. So it is readily applicable to many commercial-off-the-shelf mobile devices like cell phones. Our system is the result of several design goals, including user privacy, decentralized administration, and low cost. Rather than relying on any centralized management which tracks the user’s location to help them find their distance, our system helps devices learn their distance from each other without advertising their location information with any centralized management. Compared to alternatives that require special-purpose hardware or pre-existence of precision location infrastructure , our system is applicable on most of off-the-shelf components so it is a commodity-based solution will obviously have wider applications and is cost effective. Currently, two smartphones are used to estimate the distance between them through Wi-Fi and audio communications. The basic idea is estimating the distance between two phones by estimating the traveling time of audio signal from one phone to the other as the speed of sound is known. The preliminary results of ranging demonstrate that our algorithm could achieve high accuracy, and stable and reliable results for real time smartphone-based indoor ranging

    A Case Study for Financial Feasibility of Automated Costing Support in A Small Machine Shop

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    A knowledge-based cost estimating expert system is chosen by a Mexican machine shop. Differences between the traditional experience-based system employed and the automated system are studied. Data is gathered to analyze time effectiveness, accuracy and payback of the software. Data from seventy part models is recorded to study the time experiment, and data from fifty part models is used to study the accuracy and consistency. Data is analyzed by calculating mean, standard deviation, and test of hypothesis. The results indicate that the software is faster than the traditional quoting system; however, the payback point is high. Also, results show the software has a smaller average time-to-manufacture percentage difference between the automated system and the actual time-to-manufacture (TTM) compared to the percentage difference between the traditional’s TTM and actual TTMs, and this difference is statistically significant. The standard deviation for the automated system is also less implying better consistency

    Road2CPS priorities and recommendations for research and innovation in cyber-physical systems

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    This document summarises the findings of the Road2CPS project, co-financed by the European Commission under the H2020 Research and Innovation Programme, to develop a roadmap and recommendations for strategic action required for future deployment of Cyber-Physical Systems (CPS). The term Cyber-Physical System describes hardware-software systems, which tightly couple the physical world and the virtual world. They are established from networked embedded systems that are connected with the outside world through sensors and actuators and have the capability to collaborate, adapt, and evolve. In the ARTEMIS Strategic Research Agenda 2016, CPS are described as ‘Embedded Intelligent ICT Systems’ that make products smarter, more interconnected, interdependent, collaborative, and autonomous. In the future world of CPS, a huge number of devices connected to the physical world will be able to exchange data with each other, access web services, and interact with people. Moreover, information systems will sense, monitor and even control the physical world via Cyber-Physical Systems and the Internet of Things (HiPEAC Vision 2015). Cyber-Physical Systems find their application in many highly relevant areas to our society: multi-modal transport, health, smart factories, smart grids and smart cities amongst others. The deployment of Cyber-Physical Systems (CPS) is expected to increase substantially over the next decades, holding great potential for novel applications and innovative product development. Digital technologies have already pervaded day-to-day life massively, affecting all kinds of interactions between humans and their environment. However, the inherent complexity of CPSs, as well as the need to meet optimised performance and comply with essential requirements like safety, privacy, security, raises many questions that are currently being explored by the research community. Road2CPS aims at accelerating uptake and implementation of these efforts. The Road2CPS project identifying and analysing the relevant technology fields and related research priorities to fuel the development of trustworthy CPS, as well as the specific technologies, needs and barriers for a successful implementation in different application domains and to derive recommendations for strategic action. The document at hand was established through an interactive, community-based approach, involving over 300 experts from academia, industry and policy making through a series of workshops and consultations. Visions and priorities of recently produced roadmaps in the area of CPS, IoT (Internet of Things), SoS (System-of-Systems) and FoF (Factories of the Future) were discussed, complemented by sharing views and perspectives on CPS implementation in application domains, evolving multi-sided eco-systems as well as business and policy related barriers, enablers and success factors. From the workshops and accompanying activities recommendations for future research and innovation activities were derived and topics and timelines for their implementation proposed. Amongst the technological topics, and related future research priorities ‘integration, interoperability, standards’ ranged highest in all workshops. The topic is connected to digital platforms and reference architectures, which have already become a key priority theme for the EC and their Digitisation Strategy as well as the work on the right standards to help successful implementation of CPSs. Other themes of very high technology/research relevance revealed to be ‘modelling and simulation’, ‘safety and dependability’, ‘security and privacy’, ‘big data and real-time analysis’, ‘ubiquitous autonomy and forecasting’ as well as ‘HMI/human machine awareness’. Next to this, themes emerged including ‘decision making and support’, ‘CPS engineering (requirements, design)’, ‘CPS life-cycle management’, ‘System-of-Systems’, ‘distributed management’, ‘cognitive CPS’, ‘emergence, complexity, adaptability and flexibility’ and work on the foundations of CPS and ‘cross-disciplinary research/CPS Science’

    Air Force Institute of Technology Contributions to Air Force Research and Development, Calendar Year 1987

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    From the introduction:The primary mission of the Air Force Institute of Technology (AFIT) is education, but research and consulting are essential integral elements in the process. This report highlights AFIT\u27s contributions to Air Force research and development activities [in 1987]

    Um modelo de previsão de demanda no varejo do setor de saúde e bem-estar

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    TCC(graduação) - Universidade Federal de Santa Catarina. Centro Tecnológico. Engenharia de ProduçãoNo setor de varejo, a previsão de demanda é uma informação crítica, podendo afetar diretamente a eficiência operacional das empresas e o nível de serviço prestado ao cliente. Entretanto, prever não é uma tarefa trivial. A crescente variedade e complexidade dos problemas de previsão resultou na necessidade de modelos preditivos cada vez mais complexos e de difícil parametrização. De forma geral, modelos mais complexos requerem mais dados e ajustes para serem treinados e, consequentemente, exigem um maior custo computacional. Quando se há um grande número de itens a serem previstos, o processo de previsão demanda pode demorar várias horas, ou até mesmo dias, o que pode ser prejudicial para a operação. Dessa forma, o presente estudo visa propor um modelo de previsão de demanda no varejo do setor de saúde e bem-estar que melhore a acurácia de predição e seja equilibrado em termos de custo computacional e desempenho. Para isto, o modelo desenvolvido incorpora classes de métodos preditivos como Suavização Exponencial, modelos ARIMA, SARIMA e Redes Neurais Recorrentes. As abordagens de seleção individual, na qual determina-se e aplica-se o melhor modelo preditivo em cada série individual, e seleção agregada, onde o modelo com melhor performance para a população como um todo é determinado e aplicado, foram testadas e comparadas. Técnicas de clusterização de séries temporais foram empregadas com o intuito de aprimorar o método da seleção agregada. Dessa forma, buscou-se o método preditivo a ser aplicado em cada cluster, ao invés de buscar um único método para toda a população. As séries temporais dos centroides obtidos foram utilizadas para eleger o método preditivo a ser utilizado em cada cluster e o resultado dessa abordagem foi comparado com uma árvore de regressão. O custo computacional na seleção agregada foi 96,7% menor comparado com a seleção individual. Em contrapartida, houve um aumento de 9,5% no erro médio de previsão. Em vista dos resultados, empregou-se a abordagem seleção agregada. Em comparação com o modelo corrente na empresa objeto de estudo, os resultados do modelo proposto demonstraram reduções consideráveis no erro de previsão a um custo médio de processamento do modelo de apenas 2,09 segundos por SKU. Ademais, a seleção do método preditivo para cada cluster através dos centroides demonstrou ser uma estimativa com grande potencial de aplicação

    A Multi-Agent Architecture for An Intelligent Web-Based Educational System

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    An intelligent educational system must constitute an adaptive system built on multi-agent system architecture. The multi-agent architecture component provides self-organization, self-direction, and other control functionalities that are crucially important for an educational system. On the other hand, the adaptiveness of the system is necessary to provide customization, diversification, and interactional functionalities. Therefore, an educational system architecture that integrates multi-agent functionality [50] with adaptiveness can offer the learner the required independent learning experience. An educational system architecture is a complex structure with an intricate hierarchal organization where the functional components of the system undergo sophisticated and unpredictable internal interactions to perform its function. Hence, the system architecture must constitute adaptive and autonomous agents differentiated according to their functions, called multi-agent systems (MASs). The research paper proposes an adaptive hierarchal multi-agent educational system (AHMAES) [51] as an alternative to the traditional education delivery method. The document explains the various architectural characteristics of an adaptive multi-agent educational system and critically analyzes the system’s factors for software quality attributes

    NASA Technology Plan 1998

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    This NASA Strategic Plan describes an ambitious, exciting vision for the Agency across all its Strategic Enterprises that addresses a series of fundamental questions of science and research. This vision is so challenging that it literally depends on the success of an aggressive, cutting-edge advanced technology development program. The objective of this plan is to describe the NASA-wide technology program in a manner that provides not only the content of ongoing and planned activities, but also the rationale and justification for these activities in the context of NASA's future needs. The scope of this plan is Agencywide, and it includes technology investments to support all major space and aeronautics program areas, but particular emphasis is placed on longer term strategic technology efforts that will have broad impact across the spectrum of NASA activities and perhaps beyond. Our goal is to broaden the understanding of NASA technology programs and to encourage greater participation from outside the Agency. By relating technology goals to anticipated mission needs, we hope to stimulate additional innovative approaches to technology challenges and promote more cooperative programs with partners outside NASA who share common goals. We also believe that this will increase the transfer of NASA-sponsored technology into nonaerospace applications, resulting in an even greater return on the investment in NASA

    New methods in Palaeopalynology: Classification of pollen through pollen chemistry

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    Pollen grains are one of the primary tools of palaeoecologists to reconstruct vegetation changes in the past. The description, counting and analysis of pollen grains (palynology) has contributed to our understanding of establishment and dynamics of past and present plant communities. Advances in identification accuracy, precision and increased taxonomic resolution have greatly improved our understanding of biogeography and plant community interactions. Nevertheless, the techniques by which palynological studies are performed have not fundamentally changed. Taxonomic resolution and automation have been identified as some of the key challenges for palynology and palaeoecology. Chemical methods have been proposed as a potential alternative to morphological approaches and have demonstrated promising results in the classification of modern pollen grains and in the analysis of pollen chemical responses to UV-B radiation. The application of chemical methods for palynological needs have not been thoroughly explored, with analysis of (sub-)fossil pollen lagging behind their modern counterpart. Especially the application of infrared methods have gained popularity as an alternative to traditional morphological approaches. In this thesis, I explore the use of infrared methods for palynological applications, by exploring the chemical variation in modern pollen grains and in the analysis of fossil pollen grains with IR microscope approaches. The objectives of this thesis are formulated into three research objectives: * Collect modern pollen and explore the variation in chemical composition * Apply chemical methods to fossil material * Explore microscopy chemical methods on modern pollen The thesis is structured into four studies to study these objectives. Papers I and II explore variation and classification based on the chemical composition of modern *Quercus* pollen using two IR approaches, Fourier transform infrared spectroscopy (FTIR) and Fourier transform Raman spectroscopy (FT-Raman). After exploring modern chemical composition of pollen, paper III investigates FTIR methods for the analysis of fossil pollen, in spectra of Holocene *Pinus* pollen. Additionally, the effects of acetolysis and density separation on *Pinus* pollen is described. Paper IV addresses the challenge of scattering signals when measuring small pollen grains of four *Quercus* species with FTIR microscopy and ways to surpress or weaken the scattering signals. The results from paper I and II show classification success, surpassing traditional morphological approaches, at the *Quercus* section level and ~90% recall on species level with both IR approaches. Chemical bands most useful for classification are lipids, sporopollenin and proteins for both FT-Raman and FTIR. We observe differences in the importance of chemical functional groups for the classification. FT-Raman relies more on sporopollenin chemistry, while FTIR utilizes more variation in lipid bands. After finding considerable variation in sporopollenin chemistry in modern pollen samples, FTIR methods were applied to pollen from sediment cores spanning the Holocene. Paper III examines the differences between modern and sub-fossil pollen and reported large differences between them, mainly the removal of labile components, such as lipids and protein peaks from the sub-fossil spectra during diagenesis. Additionally, paper III finds changes to pollen chemistry caused by acetolysis in the 1200 - 1000 cm^-1^ region of the spectra, when comparing acetolysed spectra to non-acetolysed spectra. The paper concludes with findings of unwanted inorganic signals (BSi) and contamination from density separation media in the sediment pollen spectra. Paper IV demonstrates two successful methods of removing scattering signals from pollen spectra. Two approaches were examined, embedding and processing with signal correction algorithms. Spectra from embedded pollen have no scattering anomalies, but part of the spectra is unusable, because of absorbance of the embedding matrix (paraffin). The signal processing algorithm removes most of the scatter components and allows the scatter components to be extracted. Classification of the different data-sets (spectra without correction, embedded spectra, processed spectra, scatter parameters) reveals that scatter correction methods reduce classification success and that scatter parameters contain taxonomic information. This suggests that scatter corrections may not be the best approach for applications mainly focused on classification or identification, while reconstructions of, for example, UV-B radiation may benefit from scatter correction methods, when measuring single grain spectra. This thesis shows that the performance of IR methods surpasses traditional morphological methods for pollen classification and that a considerable amount of taxonomic information is stored in functional groups associated with sporopollenin (phenylpropanoids). In a study on fossil pollen, this thesis demonstrates that conventional chemical extraction methods, such as acetolysis, alter the chemical composition of pollen and may not be ideal for palaeochemical purposes. Additionally, the scatter correction methods show that IR can provide non-chemical information in the form of scatter parameters, which contain taxonomic information. These results are useful additions to the growing knowledge on chemical methods for palaeoecological and palynological analyses.Doktorgradsavhandlin

    Analysis and Synthesis of Magnetically Negative (MNG) Material using Softcomputing Techniques

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    Unique properties of Metamaterial are widely used in Electromagnetic Engineering, and the metamaterial has gained significant attention to be a major research area. Some of its recent research areas are carpet cloaking and metasurface design. The unique properties of these materials include simultaneous negative electromagnetic property, i.e., both permeability and permittivity are negative, because of which a negative refractive index is generated.Thus there are three primary classes of metamaterials. When only the permittivity is negative, the material is called ENG (Electrical Negative). Similarly material with only negative permeability is known as MNG (Magnetic Negative). Further when both are negative the material is regarded as DNG (Double Negative). Out of these three, the analysis and synthesis of MNG is very complicated and difficult. Therefore, the focus in this work is only on MNG, and the word "metamaterial" refers to MNG unless otherwise mentioned specifically. These type of materials don’t occur in nature and hence manufactured by making array of small unit cells of specific structure(s) made up of conductors. Although the concept of the existence of negative refractive index was proposed in the 1960s by Veselago, it took around 40 years to be verified practically when smith et al. did the experiment in 2001. They used an array of unit cell structures as Split-Ring-Resonators (SRR) and thin wires to verify the concept. Thereafter researchers are working to develop different forms of metamaterial unit cells and for which metamaterial is still an open area of research. However, while designing a metamaterial unit cell, absence of an empirical formula makes the model analysis and synthesis difficult. Although with the help of EM simulation tools this is possible, it usually is too difficult, time consuming and costly. Due to this researchers are motivated to look for alternative methods. In this work, some techniques to develop CAD models are presented based on soft computing techniques for metamaterial analysis and synthesis. Use of different soft computing techniques in the field of microwave engineering is documented in the literature. However, unconventional unit cell structures are difficult to analysis because of unavailability of predefined mathematical formulas and equivalent analysis. This can be done by the complex Modified Nicolson-Ross-Weir (NRW) method with the support of EM simulation tools which are expensive. Frequency dependency of metamaterial characteristics for any kind of unit cell structure follows a similar pattern which is obtained from Lorentz model. The basic idea in this work, which develops CAD Models for metamaterial unit cell of unconventional structures is based on the assumption that each type of unit cell can be mapped to an equivalent SRR structure, for which empirical formula is available. This is done by implementing the concept of Space Mapping technique or surrogate based modeling. Most important contribution of the work is the development of Space Mapped CAD model for analysis of an Ω atom. The developed model is validated with a Deformed-Ω atom, which is developed by integrating the concept of Space Mapping (SM) and Artificial Neural Network. Thereafter, the work progresses with proposing CAD models for synthesis of SRR. The objective is to find the design parameters of SRR for a desired material characteristic and frequency. With the availability of only a complex non-linear analysis formula, the synthesis becomes a reverse engineering problem, which is difficult to process. Three different models are proposed to solve the problem. The first approach is use of Inverse Artificial Neural Network concept, which uses a trained neural network (IANN) to perform output-to-input mapping. The developed CAD model using this approach includes integration of three concepts: IANN, Prior Knowledge Input-Difference (PKI-D) and SM. Although the model is capable of synthesizing a metamaterial unit cell, still it has some disadvantages. To overcome the disadvantages (such as lower convergence rate, lower accuracy and complex programming), use of Evolutionary Algorithms (Genetic Algorithm and Differential Evolution) is proposed. While developing CAD model based on EA, the methodology is first tested by synthesizing Rectangular Microstrip Antenna (RMPA) and then using the same concept, an SRR is synthesized. A comparison shows DE based model to be more efficient than IANN and GA based models in terms of convergence speed, accuracy and robustness
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