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Wideband loaded wire bow-tie antenna for near field imaging using genetic algorithmsChung, Siau Wei Jonis, Abd-Alhameed, Raed, See, Chan H., Excell, Peter S. January 2008 (has links)
Yes / The potentially broad application area in engineering design using Genetic Al-
gorithm (GA) has been widely adopted by many researchers due to its high consistency and
accuracy. Presented here is the initial design of a wideband non-dispersive wire bow-tie antenna using GA for breast cancer detection applications. The ultimate goal of this design is to achieve minimal late-time ringing but at higher frequencies such as that located from 4 to 8 GHz, in which is desire to penetrate human tissue for near field imaging. Resistively loading method to reduce minimal ringing caused by the antenna internal reflections is implemented and discussed when the antenna is located in free space and surrounded by lossy medium. Results with optimised antenna geometry and di®erent number of resistive loads are presented and compared with and without existence of scatterers.
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Tip-enhanced near-field optical microscopyNeacsu, Corneliu Catalin 14 February 2011 (has links)
Die vorliegende Arbeit beschreibt neue Entwicklungen im Verständnis und in der Umsetzung der optischen Nahfeldmikroskopie (scattering - type scanning near-field optical microscopy, s-SNOM) für die lineare und nichtlineare optische Bildgebung mit ultrahoher Auslösung und Empfindlichkeit. Die fundamentalen Mechanismen, die der Feldverstärkung am Ende von ultrascharfen metallischen Spitzen zugrunde liegen, werden systematisch behandelt. Die plasmonischen Eigenschaften der Spitze wurden erstmalig beobachtet, und ihre Bedeutung für die optische Kopplung zwischen Spitze und Probe sowie für die sich ergebende Einengung des Nahfeldes wird diskutiert. Ein aperturloses Nahfeldmikroskop für die spitzenverstärkte Ramanspektroskopie (tip-enhanced Raman spectroscopy, TERS) wurde entwickelt. Die Grundlagen der TERS und die wesentliche Rolle des plasmonischen Verhaltens der Spitze sowie die klare Unterscheidung von Nahfeld-Ramansignatur und Fernfeld-Abbildungsartefakten werden beschrieben. Nahfeld Raman Verstärkungsfaktoren von bis zu 10 wurden erreicht, was einer Feldverstärkung von bis zu 130 entspricht und Raman-Messungen bis auf Einzel-Molekül-Niveau ermöglichte. Die optische Frequenzverdopplung (second harmonic generation, SHG) an einzelnen Spitzen wurde untersucht. Aufgrund ihrer teilweise asymmetrischen Nanostruktur erlauben die Spitzen eine klare Unterscheidung von lokalen Oberflächen und nichtlokalen Volumenbeiträgen zur nichtlinearen Polarisation sowie die Analyse ihrer Polarisations- und Emissions-Auswahlregeln. Die spitzenverstärkte Frequenzverdopplungs-Spektroskopie und die räumlich hoch aufgelöste Abbildung auf Basis des dielektrischen Kontrasts werden demonstriert. Mit Hilfe einer phasen-sensitiven, Selbst-homodyn-Frequenzverdopplungs-s-SNOM-Abbildungsmethode kann die Oberflächen-Struktur der intrinsischen 180-Domänen im hexagonal multiferroischen YMnO aufgelöst werden. / This thesis describes the implementation of scattering-type near-field optical microscopy (s-SNOM) for linear and nonlinear optical imaging. The technique allows for optical spectroscopy with ultrahigh spatial resolution. New results on the microscopic understanding of the imaging mechanism and the employment of s-SNOM for structure determination at solid surfaces are presented. The method relies on the use of metallic probe tips with apex radii of only few nanometers. The local-field enhancement and its dependence on material properties are investigated. The plasmonic character of Au tips is identified and its importance for the optical tip-sample coupling and subsequent near-field confinement are discussed. The experimental results offer valuable criteria in terms of tip-material and structural parameters for the choice of suitable tips required in s-SNOM. An near-field optical microscope is developed for tip-enhanced Raman spectroscopy (TERS) studies. The principles of TERS and the role of the tip plasmonic behavior together with clear distinction of near-field Raman signature from far-field imaging artifacts are described. TERS results of monolayer and submonolayer molecular coverage on smooth Au surfaces are presented. Second harmonic generation (SHG) from individual tips is investigated. As a partially asymmetric nanostructure, the tip allows for the clear distinction of local surface and nonlocal bulk contributions to the nonlinear polarization and the analysis of their polarization and emission selection rules. Tip-enhanced SH microscopy and dielectric contrast imaging with high spatial resolution are demonstrated. SHG couples directly to the ferroelectric ordering in materials and in combination with scanning probe microscopy can give access to the morphology of mesoscopic ferroelectric domains. Using a phase sensitive self-homodyne SHG s-SNOM imaging method, the surface topology of 180 intrinsic domains in hexagonal multiferroic YMnO is resolved.
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Planar Lensing Lithography: Enhancing the Optical Near Field.Melville, David O. S. January 2006 (has links)
In 2000, a controversial paper by John Pendry surmised that a slab of negative index material could act as a perfect lens, projecting images with resolution detail beyond the limits of conventional lensing systems. A thin silver slab was his realistic suggestion for a practical near-field superlens - a 'poor-mans perfect lens'. The superlens relied on plasmonic resonances rather than negative refraction to provide imaging. This silver superlens concept was experimentally verified by the author using a novel near-field lithographic technique called Planar Lensing Lithography (PLL), an extension of a previously developed Evanescent Near-Field Optical Lithography (ENFOL) technique. This thesis covers the computational and experimental efforts to test the performance of a silver superlens using PLL, and to compare it with the results produced by ENFOL. The PLL process was developed by creating metal patterned conformable photomasks on glass coverslips and adapting them for use with an available optical exposure system. After sub-diffraction-limited ENFOL results were achieved with this system additional spacer and silver layers were deposited onto the masks to produce a near-field test platform for the silver superlens. Imaging through a silver superlens was achieved in a near-field lithography environment for sub-micron, sub-wavelength, and sub-diffraction-limited features. The performance of PLL masks with 120-, 85-, 60-, and 50-nm thick silver layers was investigated. Features on periods down to 145-nm have been imaged through a 50-nm thick silver layer into a thin photoresist using a broadband mercury arc lamp. The quality of the imaging has been improved by using 365 nm narrowband exposures, however, resolution enhancement was not achieved. Multiple layer silver superlensing has also been experimentally investigated for the first time; it was proposed that a multi-layered superlens could achieve better resolution than a single layer lens for the same total silver thickness. Using a PLL mask with two 30-nm thick silver layers gave 170-nm pitch sub-diffraction-limited resolution, while for a single layer mask with the same total thickness (60 nm) resolution was limited to a 350-nm pitch. The proposed resolution enhancement was verified, however pattern fidelity was reduced, the result of additional surface roughness. Simulation and analytical techniques have been used to investigate and understand vi ABSTRACT the enhancements and limitations of the PLL technique. A Finite-Difference Time- Domain (FDTD) tool was written to produce full-vector numerical simulations and this provided both broad- and narrowband results, allowing image quality as a function of grating period to be investigated. An analytical T-matrix method was also derived to facilitate computationally efficient performance analysis for grating transmission through PLL stacks. Both methods showed that there is a performance advantage for PLL over conventional near-field optical lithography, however, the performance of the system varies greatly with grating period. The advantages of PLL are most prominent for multi-layer lenses. The work of this thesis indicates that the utilisation of plasmonic resonances in PLL and related techniques can enhance the performance of near-field lithography.
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Design and development of novel radio frequency sensors based on far-field and near-field principlesThai, Trang Thuy 13 January 2014 (has links)
The objective of this work is to enhance and advance sensing technologies with the design and development of novel radio frequency (RF) sensors based on far-field and near-field principles of the electromagnetic (EM) resonances. In the first part of this thesis, original design and development of a passive RF temperature sensor, a passive RF strain sensor, and a passive RF pressure sensor are presented. The RF temperature sensor is presented in Chapter 3. It is based on split ring resonators loaded with bimorph cantilevers. Its operating principles and equivalent circuits are discussed in Chapter 4, where the design concept is illustrated to be robust and highly adaptable to different sensing ranges, environments, and applicable to other type of sensing beyond temperatures. The passive RF strain sensor, based on a patch antenna loaded with a cantilever-integrated open loop, is presented in Chapter 5, where it is demonstrated to have the highest strain sensitivity in the same remote and passive class of sensors in the state-of-the-art. Chapter 6 describes the passive RF pressure sensor, which is based on a dual-band stacked-patch antenna that allows both identification and sensing to be embedded in its unique dual resonant responses.
In the second part of this thesis, an original and first-of-its-kind RF transducer is presented that enables non-touch sensing of human fingers within 3 cm of proximity (based on one unit sensor cell). The RF transducer is based on a slotted microstrip patch coupled to a half-wavelength parallel-coupled microstrip filter operating in the frequency range of 6 – 8 GHz. The sensing mechanism is based on the EM near-field coupling between the resonator and the human finger. Fundamentally different from the electric field capacitive sensing, this new method of sensing, the first of its kind, based on near-field interference that produces a myriad of nonlinearities in the sensing response, can introduce new capabilities for the interface of electronic displays (the detection is based on pattern recognition). What set this sensor and its platform apart from previous proximity sensors and microwave sensing platforms is the low profile planar structure of the system, and its compatibility with mobile applications.
The thesis provides both breadth and depth in the proposed design and development and thus presenting a complete research in its contributions to RF sensing.
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Legal Aspects of Electronic Money: Financial Inclusion Instrument. The Peruvian Model / Aspectos Jurídicos del Dinero Electrónico: Instrumento de Inclusión Financiera. El Modelo PerúCipriano Pirgo, Manuel 10 April 2018 (has links)
In the first part, the background of electronic money is explained, then it provides a detailed account of how it has evolved in Africa, where there has been a huge success, given the advantages and applications it has, and how it has been working. Elsewhere, other models of electronic money that are emerging in the world, such as Google Wallet, Apple Pay, and experiences in Peru as Wanda and Your Mobile Money.In the third part, some aspects of the recent regulation of electronic money in Peru are required by Act No. 29985, which regulates the basic characteristics of electronic money. Finally, it details the recent proposal that ASBANC has been working on through the Model Peru, as well as technological and regulatory risks that still must be faced. / En una primera parte se explica los antecedentes del dinero electrónico, luego se pasa a exponer detalladamente de cómo éste se ha desarrollado en África, donde ha tenido un enorme éxito dadas las ventajas y aplicaciones que tiene, y la manera como viene funcionando. En otra parte se señalan otros modelos de dinero electrónico que vienen surgiendo en el mundo, tales como Google Wallet, Apple Pay, y experiencias en Perú como el de Wanda y Tu Dinero Móvil.En la tercera parte se precisan algunos aspectos de la reciente regulación del dinero electrónico en el Perú, mediante la Ley Nº 29985, que regula las características básicas del Dinero Electrónico. Finalmente se detalla la reciente propuesta que viene trabajando ASBANC, a través del Modelo Perú, así como los riesgos tecnológicos y regulatorios que aún se debe afrontar.
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Near Field Communication : En studie om NFC-teknikens möjliga användningsområden och utveckling inom sociala medier / Near Field Communication : A study on the NFC technology’s possible field of application and its development within social mediaHamberg, Lisa, Huber, Christine January 2014 (has links)
In this report we examine the NFC (Near Field Communication) technology as far as the development has come until today. We adress different use areas and explain the technical funcionality. By using data collection methods as a specialist interview and also a survery we want to detect potential risks and safety-issues in implementation of the new technology. Our main-focus in this report is to examine how NFC can play an important role in the developement of social interaction and social media. By compiling our data and research materials we will analyze and present a report conslusion. In our conclusion we will introduce our thoughts about the technology as NFC gets more and more common in our physical lives and also propose further research-areas. We will share potential risks about the technology as it is developing to alert future researchers and developers, but also pay attention to the opportunities the technology may bring. / Med vår studie har vi valt att undersöka tekniken NFC (eng. Near Field Communication) så långt som utvecklingen har kommit i dagsläget. Vi redogör kring vad det finns för olika användningsområden och hur NFC fungerar ur ett tekniskt perspektiv. Genom att intervjua en person som arbetar nära tekniken samt utföra en enkätundersökning vill vi upptäcka potentiella säkerhetsrisker som medföljer implementeringen av tekniken. Studiens huvudfokus är att undersöka hur och om NFC kan ha en viktig roll i utvecklingen och framtiden för sociala medier och interaktion. Med den data vi samlar in under studiens gång kommer vi analysera, diskutera och komma fram till en slutsats. Vi kommer att delge våra tankar kring teknologin då den blir mer och mer vanlig i våra fysiska liv och föreslå vidare forskningsområden. Vi vill uppmärksamma framtida forskare och utvecklare av NFC om potentiella risker som tekniken medför, men också de möjligheter som tekniken öppnar upp.
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Metody akustické holografie v blízkém poli v prostředí LabVIEW / Near-field acoustical holography methods in LabVIEW environmentMajvald, František January 2021 (has links)
Near-field acoustical holography is a standard method for sound source visualization and localization. In this thesis, commonly used and newly published near-field acoustic holography methods are introduced and analysed. In addition, regularization methods are presented together with finding options of optimal regularization parameter. Based on theory, a LabVIEW library is built containing four implemented near-field acoustical holography algorithms and two regularization methods. To verify the correctness of implementations, a testing application has been made. This application allows testing of implemented algorithms with simulated or experimentally measured data. The correctness of implementation is verified, and algorithms are compared to each other with respect to accuracy and speed of calculation.
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Implementation av prototyp för inomhuspositionering / Prototype Implementation for Indoor PositioningAndersson, Dan January 2013 (has links)
Utveckling av teknik skapar ständigt nya möjligheter men innebär också stora förändringar för företag och organisationer. Mobiltelefoner, surfplattor, bärbara datorer, mobilkommunikation och molnteknik gör det möjligt idag att inte längre vara bunden av tid, plats eller en enhet för att kunna arbeta. Förändringen innebär att en ny typ av flexibla och yteffektiva kontor med inga fasta arbetsplatser blir allt vanligare. Problemet med de så kallade flexkontoren är att veta var eller när en kollega befinner sig på kontoret är inte lika självklart, framförallt om det är stort kontor med flera våningsplan. Målsättningen med detta arbete är att ta fram och implementera en inomhuspositioneringstjänst eller en så kallad Location-Based Service, till företaget Connecta AB. Tjänsten ska göra det möjligt för användare att med hjälp av sin mobiltelefon dela med sig av sin nuvarande arbetsplats i en kontorsmiljö. Resultatet av arbetet är en Location Based Service som gör det möjligt för en användare att med hjälp av en Androidtelefon med stöd för kortdistanskommunikationstekniken Near Field Communcication att dela med sig av sin nuvarande arbetsplats. Den molnbaserade serverlösningen Windows Azure används för att lagra registrerade arbetsplatser. / Development of technology constantly creates new opportunities but it can also mean major chang-es for companies and organizations. Today phones, tablets, laptops, mobile communications and cloud technology make it possible to be no longer bound by the time, location or device in order to work. The change means that a new office type that is more flexible and space efficient due to no fixed workplaces, is becoming more common. A problem with this type of offices that are known as flex-offices is that it is not obvious where or when a colleague is in the office, especially if it is large office with multiple floors. The aim of this work is to develop and implement a Location-Based Service for the company Connecta AB. The service will enable users to use their mobile phone to share their current workplace location in an office environment. The result of this work is a Location-Based Service that enables a user to use an Android phone with support for Near Field Communcication to share their current workplace position. The cloud-based server solution, Windows Azure is used to store indexed workplace positions.
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Kontaktlösa betalningar med smarta telefoner / Contactless payments with smartphonesKornberg Valentine, Philip, Alkuheli, Zaid January 2021 (has links)
Företaget Hajenterprise vill göra en forskning inom kommunikation för att hantera kontaktlösa betalningar för att kunna ta betalt kontaktlöst med hjälp av mobilen. Idag används bankkort för att betala för de flesta saker. Nya betalningssätt har rört sig mot kontaktlösa köp med hjälp av smarta telefoner och NFC-teknologier. Smarta telefoner har börjat användas mer och mer i kontaktlösa köp mot point of sale (POS) terminaler. Skulle det då gå att kunna ta bort POS-terminaler och använda smarta telefoner som POS-terminaler? För att besvara detta behövdes tester utföras för att se ifall en smart telefon skulle kunna läsa ett bankkort och behandla bankkortets information. Bankkort kunde läsas av de smarta telefonerna men informationen från bankkortet kunde inte användas av den smarta telefonen för att genomföra en betalning. Detta var eftersom beroende på telefon, öppnades Samsung, Google eller Apple pay. En smart telefon kunde alltså ta emot information från ett bankkort men telefonen kunde inte använda den information för att utföra en betalning på en terminal. Utöver forskningen av olika betalningssätt, skapades en applikation där betalning skulle kunna utföras från en mobil till en annan mobil. Detta skulle ske med hjälp av Near Field Communication (NFC) och blockchain, eftersom Hajenterprise vill ha en prototyp-applikation som skulle kunna betala och ta betalt över NFC mot deras blockchain. JavaScript användes för att skapa en react native applikation som kunde fungera på både Android och iOS. Detta lade grunden så att Hajenterprise kunde använda sitt blockchain-api för mobila betalningar. / The company Hajenterprise wanted to research the area of contactless payments to see if it’s possible to Pay contactless with a mobile phone. Today bank cards are used to pay for most things. New payment methods have moved toward contactless purchases using smart phones and NFC-technologies. Smart phones have begun to be used more and more in contactless purchases at point of sale (POS) terminals. The possibility to remove POS-terminals and use smartphones instead as POS-terminals could make it easier and faster to pay. To test this, several tests were needed to see if a smartphone could read a bank card and process the card's information. Bank cards could be read by the smartphone but the information from the bank card could not be used by the smartphone to make a payment. This was because depending on the phone, Samsung, Google or Apple Pay was opened. Thus, a smart phone could receive information from a card but the phone could not use that information to make a payment at a terminal. In addition, an application was created where one could make payments from one mobile to another mobile. This would be done using Near Field Communication (NFC) and blockchain, as Hajenterprise wanted a prototype-application that could pay and charge over NFC against their blockchain. JavaScript was used to create a react native application that could work on both Android and iOS. This laid the foundation for Hajenterprise to use its blockchain API for mobile payments.
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Communicating with a Smart Pillbox via Near Field Communication (NFC) : A Mobile Application for Healthcare ProfessionalsAl-qaysi, Ibrahim January 2018 (has links)
The lack of medication adherence leads to an incremental risk of diseases which can be a major burden on the individual, healthcare system, and society. Hence, healthcare professionals have a central role and should manage, guide, educate, and make their patient more involved in their treatment and thereby promoting a better medication adherence. Medication adherence is a great challenge for many patients with chronic conditions, elderly patient, or patient prescribed to long-term medication. The rapid development and deployment of mobile phones in the healthcare industry has an important role to play in this area and has led to the development of new phone features and applications that can help both caregivers and patients with managing and monitoring medication intakes. This development and support of mobile phones and applications have created and improved doctor-patient interaction. Today, there is no easy way for healthcare professionals to monitor and help patients with their medication intakes. A solution to this problem is to develop a mobile application that communicates with a smart pillbox via near field communication (NFC) to monitor, manage, and improve patient’s medication intakes in an easy and accessible manner. Using NFC as a communication technology allows data to be wirelessly transferred from phone to pillbox and vice versa. This solution will help healthcare professionals to create better treatment conditions and fewer side effects for their patients. These patients will be more knowledgeable and motivated to take greater responsibility in following doctor’s instructions, thereby improving their treatment process. The application is tested and evaluated during every iteration phase of the development process. These tests have been conducted by allowing healthcare professionals to test the application and provide feedback on their experience when using the app. Conducting these tests have helped with generating new ideas, features, and functionalities, but also helped to improve the user interface to make the application as user-friendly as possible. / Bristen på medicinering följsamhet leder till en ökad risk för sjukdomar som kan vara en stor belastning för individen, vårdsystemet och samhället. Hälsooch sjukvårdspersonal har därför en central roll och bör hantera, vägleda, utbilda och göra patienten mer delaktig i behandlingen och därigenom främja en bättre medicinering följsamhet. Medicinering följsamhet är en stor utmaning för många patienter med kroniska tillstånd, äldre patient eller patient som är ordinerad för långvarig medicinering. Den snabba utvecklingen och användningen av mobiltelefoner inom vårdindustrin har en viktig roll att spela i detta område och har lett till utvecklingen av nya funktioner och applikationer som kan hjälpa både vårdgivare och patienter med att hantera och övervaka medicinsk intag. Denna utveckling och support av mobiltelefoner och applikationer har skapat och förbättrat interaktion mellan läkare och patient. Idag finns det inget enkelt sätt för sjukvårdspersonal att övervaka och hjälpa patienter med sina medicinintag. En lösning på detta problem är att utveckla en mobilapplikation som kommer att kommunicera med en smart pillbox via nära fältkommunikation (eng. Near Field Communication, NFC) för att övervaka, hantera och förbättra patientens medicinintag på ett enkelt och tillgängligt sätt. Med hjälp av NFC som kommunikationsteknik kommer data att överföras trådlöst från telefon till pillerdosa och vice versa. Denna lösning kommer att hjälpa vårdpersonal att skapa bättre behandlingsförhållanden och färre biverkningar för sina patienter. Dessa patienter kommer i sin tur att vara mer kunniga och motiverade att ta större ansvar i efterföljande läkares instruktioner och därigenom förbättra deras behandlingsprocess. Applikationen har testat och utvärderat under varje iteration av utvecklingsprocessen. Dessa tester har utförts genom att låta vårdpersonal testa applikationen och ge feedback på hur dem upplevar applikationen. Dessa tester hjälper till att skapa nya idéer, funktioner och funktioner som bör ingå i den slutliga applikationen, men också bidra till att förbättra användargränssnittet för att göra ansökan så användarvänlig som möjligt.
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