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Articles 91 - 120 of 278

Full-Text Articles in Electrical and Electronics

Passive Self-Interference Suppression For Single Channel Full-Duplex Operation, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann Jan 2018

Passive Self-Interference Suppression For Single Channel Full-Duplex Operation, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann

Articles

Full duplex radios have become a topic of increased interest in the wireless communications community. As part of this development, many efforts were directed to passively decrease the self-interference level at the antenna outputs. However, in many proposed solutions transmission and reception occur through different propagation channels. This paper demonstrates and quantifies the negative impact of channel differentiation on pivotal applications of full-duplex radio, such as cognitive radio. Antenna designs used for self-interference suppression in full-duplex radio architectures are analyzed. In order to ensure that transmission and reception occur within the same propagation channel, the use of the envelope correlation …


Data Driven Prediction Model (Ddpm) For Server Inlet Temperature Prediction In Raised-Floor Data Centers, Raymond Lloyd, Marek Rebow Jan 2018

Data Driven Prediction Model (Ddpm) For Server Inlet Temperature Prediction In Raised-Floor Data Centers, Raymond Lloyd, Marek Rebow

Conference papers

Data centers account for approx. 1.4% of the world’s electricity consumption, of which up to 50% of that power is dedicated to keeping the actual equipment cool. This represents a huge opportunity to reduce data center energy consumption by tackling the cooling system operations with focus on thermal management. This work presents a novel Data Driven Predictive Model (DDPM) for temperature prediction of server inlet temperatures that utilises high resolution empirical temperature measurements from 52 real-life data centers. A knowledge-base of temperature data and related physical features, created via clustering techniques was used to train a series of artificial neural …


Silica Gel Coated Spherical Micro Resonator For Ultra-High Sensitivity Detection Of Ammonia Gas Concentration In Air, Arun Mallik, Gerald Farrell, Dejun Liu, Vishnu Kavungal, Qiang Wu, Yuliya Semenova Jan 2018

Silica Gel Coated Spherical Micro Resonator For Ultra-High Sensitivity Detection Of Ammonia Gas Concentration In Air, Arun Mallik, Gerald Farrell, Dejun Liu, Vishnu Kavungal, Qiang Wu, Yuliya Semenova

Articles

A silica gel coated microsphere resonator is proposed and experimentally demonstrated for measurements of ammonia (NH3) concentration in air with ultra-high sensitivity. The optical properties of the porous silica gel layer change when it is exposed to low (parts per million (ppm)) and even ultra-low (parts per billion (ppb)) concentrations of ammonia vapor, leading to a spectral shift of the WGM resonances in the transmission spectrum of the fiber taper. The experimentally demonstrated sensitivity of the proposed sensor to ammonia is estimated as 34.46 pm/ppm in the low ammonia concentrations range from 4 ppm to 30 ppm using an optical …


Optical Fiber Fresnel Reflection Sensor For Direct Detection Of The Solid-Liquid Phase Change In N-Octadecane, Wei Han, Marek Rebow, Dejun Liu, Yuliya Semenova, Qiang Wu Prof. Jan 2018

Optical Fiber Fresnel Reflection Sensor For Direct Detection Of The Solid-Liquid Phase Change In N-Octadecane, Wei Han, Marek Rebow, Dejun Liu, Yuliya Semenova, Qiang Wu Prof.

Articles

An all optical fiber Fresnel reflection sensor for detecting the solid–liquid phase change in n-octadecane is proposed and experimentally demonstrated. The sensor probe consists of a single-mode fiber with a cleaved end which is immersed in the material sample under test. As the n-octadecane changes from solid to liquid or from liquid to solid, its refractive index (RI) changes resulting in changes of the light power ratio reflected by the probe. Since the RI of n-octadecane during its phase transition changes discontinuously, inflection in the reflected light power ratio dependence indicates the phase change of the sample in the vicinity …


The Different Stages Of Prpd Pattern For Positive Point To Plane Corona Driven By A Dc Voltage Containing A Ripple, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher Jan 2018

The Different Stages Of Prpd Pattern For Positive Point To Plane Corona Driven By A Dc Voltage Containing A Ripple, Tobias Dezenzo, Thomas Betz, Andreas Schwarzbacher

Articles

The different phase resolved partial discharge patterns, which can be recognized when a positive dc voltage containing a ripple due to a half-wave rectification is used are presented in this paper. Results are given from corona onset to the appearance of breakdown streamers. The outcomes are five different patterns, which represent the four stages of positive corona and their transition zones. Three of them are clearly identifiable with respect to patterns from other discharge sources that have already been reported for dc voltages containing a ripple. For an assessment of pattern formation discharge pulses as recorded at the test object …


On The Application Of Pspice For Localised Cloud Security, Paul Tobin Jan 2018

On The Application Of Pspice For Localised Cloud Security, Paul Tobin

Doctoral

The work reported in this thesis commenced with a review of methods for creating random binary sequences for encoding data locally by the client before storing in the Cloud. The first method reviewed investigated evolutionary computing software which generated noise-producing functions from natural noise, a highly-speculative novel idea since noise is stochastic. Nevertheless, a function was created which generated noise to seed chaos oscillators which produced random binary sequences and this research led to a circuit-based one-time pad key chaos encoder for encrypting data. Circuit-based delay chaos oscillators, initialised with sampled electronic noise, were simulated in a linear circuit simulator …


Miniaturized Switchless Pattern Reconfigurable Antenna Utilizing Spherical Modes Analysis, Adam Narbudowicz, Max Ammann, Nicola Marchetti Jan 2018

Miniaturized Switchless Pattern Reconfigurable Antenna Utilizing Spherical Modes Analysis, Adam Narbudowicz, Max Ammann, Nicola Marchetti

Conference Papers

The paper proposes an electrically small pattern reconfigurable antenna, which allows flexible beamforming with the antenna diameter being ?/5. The antenna has 3 ports, each designed to radiate a different spherical mode. By applying appropriate phase shift the antenna allows to flexibly sweep its bi-directional radiation pattern across a 360° azimuth, while offering 5 dBi directivity.


Iot Based Recipes For Enabling Senior Citizens: Stakeholders Views On How Integration Of Iot And Web Services Can Enhance Well-Being And Inclusion Of Older People, Matteo Zallio, Damon Berry, John Mcgrory Jul 2017

Iot Based Recipes For Enabling Senior Citizens: Stakeholders Views On How Integration Of Iot And Web Services Can Enhance Well-Being And Inclusion Of Older People, Matteo Zallio, Damon Berry, John Mcgrory

Conference papers

The main body of research clearly highlights the world’s population is rapidly expanding. When this fact is combined with the increase in life longevity due to medical and social advances it alters the demographic balance in relation to age. Hence, the number of people aged 65 and over is constantly increasing. The potential of Smart Technologies and IoT-based devices to improve health has increased rapidly in the last few years and users are now in a position to contribute to the development of the interaction process and need to be properly trained on benefits of using new technologies. IFTTT (If …


A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge Jun 2017

A Hardware One-Time Pad Prototype Generator For Localising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge

Conference papers

In this paper, we examine a system for encrypting data before storing in the Cloud. Adopting this system gives excellent security to stored data and complete control for accessing data by the client at different locations. The motivation for developing this personal encryption came about because of poor Cloud security and doubts over the safety of public encryption algorithms which might contain backdoors. However, side-channel attacks and other unwanted third-party interventions in Cloud security, probably contribute more to the poor security record history. These factors led to the development of a prototype for personalising security locally which defeats cryptanalysis. The …


Chaos-Based Cryptography For Cloud Computing, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge Jun 2017

Chaos-Based Cryptography For Cloud Computing, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge

Conference papers

Cloud computing and poor security issues have quadrupled over the last six years and with the alleged presence of backdoors in common encryption ciphers, has created a need for personalising the encryption process by the client. In 2007, two Microsoft employees gave a presentation ``On the Possibility of a backdoor in the NIST SP800-90 Dual Elliptic Curve Pseudo Random Number Generators'' and was linked in 2013 by the New York Times with notes leaked by Edward Snowden. This confirmed backdoors were placed, allegedly, in a number of encryption systems by the National Security Agency, which if true creates an urgent …


On The Development Of A One-Time Pad Generator For Personalising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge Feb 2017

On The Development Of A One-Time Pad Generator For Personalising Cloud Security, Paul Tobin, Lee Tobin, Michael Mckeever, Jonathan Blackledge

Conference papers

Cloud computing security issues are being reported in newspapers, television, and on the Internet, on a daily basis. Furthermore, in 2013, Edward Snowden alleged backdoors were placed in a number of encryption systems by the National Security Agency causing confidence in public encryption to drop even further. Our solution allows the end-user to add a layer of unbreakable security by encrypting the data locally with a random number generator prior to uploading data to the Cloud. The prototype one-time pad generator is impervious to cryptanalysis because it generates unbreakable random binary sequences from chaos sources initiated from a natural noise. …


Design Of A Community-Supported Capable Microwave System For People With Intellectual And Physical Disabilities, Matteo Zallio, Damon Berry, Paula Kelly, Hicham Rifai, Modestas Jakuska Feb 2017

Design Of A Community-Supported Capable Microwave System For People With Intellectual And Physical Disabilities, Matteo Zallio, Damon Berry, Paula Kelly, Hicham Rifai, Modestas Jakuska

Conference papers

Product personalisation has become a central topic and expected part of every day life. Different people have different characteristics and abilities and every single user has different needs which means that products have to be tailored accordingly. Micro- wave ovens are one of the most commonly used home appliances. People use them to quickly heat or cook certain foods. Today, according to the US Bureau of Labor Statis- tics, more than 90% of U.S. households own a microwave oven [11]. This project seeks to enable people with intellectual disabilities and physical impairments to perform sim- ple cooking tasks. The target …


The Effect Of The Local Field And Dipole-Dipole Interactions On The Absorption Spectra Of Noble Metals And The Plasmon Resonance Of Their Nanoparticles, I.I. Shaganov, T.S. Perova, Kevin Berwick Jan 2017

The Effect Of The Local Field And Dipole-Dipole Interactions On The Absorption Spectra Of Noble Metals And The Plasmon Resonance Of Their Nanoparticles, I.I. Shaganov, T.S. Perova, Kevin Berwick

Articles

An analysis of the effect of free and bound electrons on the optical properties of noble metals and their nanoparticles is performed, based on the Drude-Lorentz model. It is shown that the shifts in the absorption bands of plasmons localized in spherical nanoparticles with respect to the zero frequency of free electrons in a bulk metal can be estimated using the theory of resonant dipole-dipole interactions. The calculation includes account for differences between the effective and average electromagnetic fields. It is established that the difference in oscillator strength for free electrons in the bulk metal, obtained using the Drude-Lorentz model, …


Optimising The Performance Of Cement-Based Batteries, Aimee Byrne, Shane Barry, Niall Holmes Dr., Brian Norton Jan 2017

Optimising The Performance Of Cement-Based Batteries, Aimee Byrne, Shane Barry, Niall Holmes Dr., Brian Norton

Articles

The development of a battery using different cement-based electrolytes to provide a low but potentially sustainable source of electricity is described. The current, voltage, and lifespan of batteries produced using different electrolyte additives, copper plate cathodes, and (usually) aluminium plate anodes were compared to identify the optimum design, components, and proportions to increase power output and longevity. Parameters examined include water/cement ratio, anode to cathode surface area ratio, electrode material, electrode spacing, and the effect of sand, aggregate, salts, carbon black, silica fume, and sodium silicate on the electrolyte. The results indicate that the greatest and longest lasting power can …


Design And Investigation Of De Vries Liquid Crystals Based On 5-Phenyl-Pyrimidine And (R,R)-2,3-Epoxyhexoxy Backbone., S.P. Sreenilayam", D. Rodriguez-Lojo, V. P. Panov, V. Swaminathan, J. K. Vij, Yuri Panarin, E. Gorecka, A. Panov, P.J. Stevenson Jan 2017

Design And Investigation Of De Vries Liquid Crystals Based On 5-Phenyl-Pyrimidine And (R,R)-2,3-Epoxyhexoxy Backbone., S.P. Sreenilayam", D. Rodriguez-Lojo, V. P. Panov, V. Swaminathan, J. K. Vij, Yuri Panarin, E. Gorecka, A. Panov, P.J. Stevenson

Articles

Calamitic liquid crystals based on 5-phenyl-pyrimidine derivatives have been designed, synthesized, and characterized. The 5-phenyl pyrimidine core was functionalized with a chiral (R,R)-2,3-epoxyhexoxy chain on one side and either siloxane or perfluoro terminated chains on the opposite side. The one involving a perfluorinated chain shows SmA^{*} phase over a wide temperature range of 82 °C, whereas the siloxane analog exhibits both SmA^{*} and SmC^{*} phases over a broad range of temperatures, and a weak first-order SmA^{*}-SmC^{*} transition is observed. For the siloxane analog, the reduction factor for the layer shrinkage R (relative to its thickness at the SmA^{*}-SmC^{*} transition temperature, …


Investigation Of Electrical Defects Arising From Excessive Sidewall Force And Excessive Tensile Strain On Power Cables, Darren Mcconnon, Joseph Kearney, Tom Looby, James O'Shaughnessy Jan 2017

Investigation Of Electrical Defects Arising From Excessive Sidewall Force And Excessive Tensile Strain On Power Cables, Darren Mcconnon, Joseph Kearney, Tom Looby, James O'Shaughnessy

Conference papers

The study includes a comprehensive review of the existing literature and guidelines regarding the effects of sidewall force and tensile strain on power cables during installation. The most appropriate diagnostic test methods required to analyse these effects are also assessed. The results of tests and analysis of the existing literature are then combined in an attempt to determine a realistic basis for guidelines and recommendations relevant to cable installation forces.


Wavelength Drift In Cwdm Systems: Impact And Measurement, Thomas Freir Jan 2017

Wavelength Drift In Cwdm Systems: Impact And Measurement, Thomas Freir

Masters

The research begins with an investigation of wavelength drift in Coarse Wavelength Division Multiplexing (CWDM) systems, especially in the context of temperature dependent wavelength drift. A simple model was proposed using a typical ‘application’ from ITU-T G.695. OptiSystem was chosen as the simulation platform due to its ease of use, the variety and flexibility of its inbuilt components and similar models simulated on the platform in the past. The research then investigates the measurement of wavelength drift focusing on how to determine an acceptable wavelength accuracy for a CWDM wavelength monitor. The chosen approach arose from observations of the results …


Aphonic: Adaptive Thresholding For Noise Cancellation In Smart Mobile Environments, Ruairí De Fréin Jan 2017

Aphonic: Adaptive Thresholding For Noise Cancellation In Smart Mobile Environments, Ruairí De Fréin

Articles

We propose a signal-channel, adaptive threshold selection technique for binary mask construction, namely APHONIC, (AdaPtive tHreshOlding for NoIse Cancellation) for smart mobile environments. Using this mask, we introduce two noise cancellation techniques that perform robustly in the presence of real-world interfering signals that are typically encountered by mobile users: a violin busker, a subway and busy city square sounds. We demonstrate that when the power of the time-frequency components of the voice of a mobile user does not significantly overlap with the components of the interference signal, the threshold learning and noise cancellation techniques significantly improve the Signal-to-Interference Ratio (SIR) …


Adaptive Environments For Enabling Senior Citizens: An Holistic Assessment Tool For Housing Design And Iot-Based Technologies, Matteo Zallio, Damon Berry, Niccolò Casiddu Dec 2016

Adaptive Environments For Enabling Senior Citizens: An Holistic Assessment Tool For Housing Design And Iot-Based Technologies, Matteo Zallio, Damon Berry, Niccolò Casiddu

Conference papers

The population of older adults will continuously increase over the coming decades. As they get older, people will require assistance and regular monitoring, with higher costs for welfare system and families. Two vital aspects of a healthy lifestyle, are domestic autonomy and maintenance of relationships within the neighborhood. This leads to an interesting research issue: “Could houses and appliances have the potential to improve autonomy and quality of life of citizens? Which methods and tools could enhance wellbeing and healthy conditions? The house has the potential to be a safe, adaptive environment, integrated with technologies for life support. This work …


Pattern Reconfigurable Back-To-Back Microstrip Patch Antenna, Kansheng Yang, Xiulong Bao, Patrick Mcevoy, Max Ammann Oct 2016

Pattern Reconfigurable Back-To-Back Microstrip Patch Antenna, Kansheng Yang, Xiulong Bao, Patrick Mcevoy, Max Ammann

Articles

A back-to- back microstrip patch antenna with a switchable pattern is proposed for WLAN applications. The patch elements, printed on FR-4 substrates with a common ground plane, are switched with a single-pole double-throw PIN diode circuit. Switching the feed selects either of two identical radiation patterns in the opposing hemispheres for spatial diversity that would benefit a distributed network.


Optical Wavelength Ratiometric Monitoring System For Data Centre Cwdm Applications, Anthony Colohan, Thomas Freir, Derek Finlay Sep 2016

Optical Wavelength Ratiometric Monitoring System For Data Centre Cwdm Applications, Anthony Colohan, Thomas Freir, Derek Finlay

Conference papers

The development of the internet and the subsequent increase in the quantity of connected devices in recent years has given rise to an explosion in demand of data traffic across telecommunication networks. Converged networks deliver high speed bit rates for the purpose of streaming videos, downloading music files and communicating over the internet; voice over internet protocol (VOIP). Further additional data traffic growth stemming from the upsurge in the amount of ‘tweets’ and instant messages (IM) created as well as emails written and cloud storage, has led to a demand for the construction of much larger data centres, which …


Bitrate Classification Of Twice-Encoded Audio Using Objective Quality Features, Colm Sloan, Damien Kelly, Naomi Harte, Anil C. Kokaram, Andrew Hines Jun 2016

Bitrate Classification Of Twice-Encoded Audio Using Objective Quality Features, Colm Sloan, Damien Kelly, Naomi Harte, Anil C. Kokaram, Andrew Hines

Conference papers

When a user uploads audio files to a music stream- ing service, these files are subsequently re-encoded to lower bitrates to target different devices, e.g. low bitrate for mobile. To save time and bandwidth uploading files, some users encode their original files using a lossy codec. The metadata for these files cannot always be trusted as users might have encoded their files more than once. Determining the lowest bitrate of the files allows the streaming service to skip the process of encoding the files to bitrates higher than that of the uploaded files, saving on processing and storage space. This …


Amorphous Silicon Solar Vivaldi Antenna, Oisin O'Conchubhair, Kansheng Yang, Patrick Mcevoy, Max Ammann Mar 2016

Amorphous Silicon Solar Vivaldi Antenna, Oisin O'Conchubhair, Kansheng Yang, Patrick Mcevoy, Max Ammann

Articles

An ultra-wideband solar Vivaldi antenna is proposed. Cut from amorphous silicon cells, it maintains a peak power at 4.25 V which overcomes a need for lossy power management components. The wireless communications device can yield solar energy or function as a rectenna for dual-source energy harvesting. The solar Vivaldi performs with 0.5 - 2.8 dBi gain from 0.95 - 2.45 GHz and in rectenna mode, it covers three bands for wireless energy scavenging.


A Techno-Economical Appraisal Of A Pv Domestic Plant On A Irish Dwelling, Roberto Sandano Jan 2016

A Techno-Economical Appraisal Of A Pv Domestic Plant On A Irish Dwelling, Roberto Sandano

Articles

A comprehensive study of a domestic PV installation is addressed in this paper. A series of economic results are presented for a domestic installation in Ireland.


Using Photovoltaics To Power Electrochemical Chloride Extraction From Concrete, Sean Bond, Lynette O'Callaghan, Niall Holmes Dr., Brian Norton Jan 2016

Using Photovoltaics To Power Electrochemical Chloride Extraction From Concrete, Sean Bond, Lynette O'Callaghan, Niall Holmes Dr., Brian Norton

Conference papers

Corrosion of embedded steel in reinforced concrete (RC) is a world-wide problem, that reduces structural performance and lifespan. Chloride attack may be a result of seawater, de-icing salts or contaminated admixtures, brought on by ingress of chlorides into the concrete. Electrochemical Chloride Extraction (ECE) is a non-destructive treatment for contaminated RC structures, that due to uncertainty of treatment times and applied current densities, is only 50% effective. It is often diesel powered has an environmental impact and often very costly due to the long treatment times. To improve the efficiency of ECE the influences of concrete resistance, cement type and …


Supervision Of Community Based Microgrids: An Economic Model Predictive Control Approach, Francesco Tedesco, Lubna Mariam, Malabika Basu, Alessandro Casavola, Michael F. Conlon Jan 2016

Supervision Of Community Based Microgrids: An Economic Model Predictive Control Approach, Francesco Tedesco, Lubna Mariam, Malabika Basu, Alessandro Casavola, Michael F. Conlon

Conference papers

Abstract— In this paper, an Economic Model Predictive Control (EMPC) approach has been presented to manage a Community-based microgrid (C-µGCC) at the pricing level. The main task is at satisfying the demand at prosumer sides and, at the same time, optimizing various µ-Grid contrasting objectives. Emphasis has been given to the operational constraints related to the components lifetime, whose satisfaction would be beneficial for the grid in that the maintenance and replacement costs would be reduced. A simulative analysis has been carried out on the basis of available measured data related to a location in Dublin, Ireland. Results show the …


A Two-Level Identity Model To Support Interoperability Of Identity Information In Electronic Health Record Systems., Xu Chen Jan 2016

A Two-Level Identity Model To Support Interoperability Of Identity Information In Electronic Health Record Systems., Xu Chen

Doctoral

The sharing and retrieval of health information for an electronic health record (EHR) across distributed systems involves a range of identified entities that are possible subjects of documentation (e.g., specimen, clinical analyser). Contemporary EHR specifications limit the types of entities that can be the subject of a record to health professionals and patients, thus limiting the use of two level models in healthcare information systems that contribute information to the EHR. The literature describes several information modelling approaches for EHRs, including so called “two level models”. These models differ in the amount of structure imposed on the information to be …


Switchless Reconfigurable Antenna With 360° Steering, Adam Narbudowicz, Max Ammann, Dirk Heberling Jan 2016

Switchless Reconfigurable Antenna With 360° Steering, Adam Narbudowicz, Max Ammann, Dirk Heberling

Conference Papers

—A novel reconfigurable antenna capable of rotating a bidirectional pattern by 360◦ in azimuth is proposed. The antenna has two ports, no aperture switching components, and offers a more compact solution than an array. It provides a reconfigurable pattern in the band 2.525–2.595 GHz and a fixed omnidirectional pattern from 2.235 to 2.725 GHz. The measured gains for four investigated configurations are between 2.1 and 3.1 dBi with total efficiencies between 80% and 89%. The antenna is intended to operate with software defined radio [digital beamforming or multiple-input–multiple-output (MIMO)], where the potential of pattern generation using the dual-port antenna can …


A Different Type Of Lighting Research: A Qualitative Methodology, Kevin Kelly Jan 2016

A Different Type Of Lighting Research: A Qualitative Methodology, Kevin Kelly

Articles

As lighting researchers we can learn from our colleagues in the humanities who have progressed Qualitative Research methods to a high level of rigour. We should consider using Qualitative Research Methods more. Such methods allow exploration of complex issues involving human behaviour and facilitate researchers to address difficult to answer questions that otherwise go unanswered. Good quality Qualitative Research can provide rich explanations of what went on in a given situation. Validity and Reliability are considered differently with this type of research methodology. This paper attempts to identify when qualitative research is appropriate, what questions it can answer in lighting …


Sol-Gel Silica Coated Optical Fiber Sensor For Ammonia Gas Detection, Dejun Liu, Arun Mallik, Wei Han, Qiang Wu Jan 2016

Sol-Gel Silica Coated Optical Fiber Sensor For Ammonia Gas Detection, Dejun Liu, Arun Mallik, Wei Han, Qiang Wu

Conference papers

A high sensitivity ammonia gas sensor based on a tapered small core single-mode fiber (SCSMF) structure for measurement of ammonia gas concentration is reported. The proposed tapered SCSMF fiber structure has a waist diameter of 13.5 μm and it is fabricated using a customized microheater brushing technique. The silica based material prepared by sol-gel method is used as a coating applied to the surface of tapered fiber structures. Experimental results show that sensor is very sensitive to ammonia. The best measurement resolution of the ammonia concentration is estimated to be 16 ppb for gas concentrations of 0.5 ppm to 2.5 …