Engineering Commons^™

Simultaneous Measurement Of Gas Pressure And Temperature Using A Microbubble Resonator Combined With An Fbg, Ketan Dong, Ke Tian, Chuanzhen Zhao, Huibin Li, Jibo Yu, Angzhen Li, Xiaoling Sun, Elfed Lewis, Gerald Farrell, Pengfei Wang

Conference Papers

We propose and demonstrate a microbubble resonator combined with a fiber Bragg grating (FBG) for simultaneous measurement of gas pressure and temperature. The approach used allows for very close proximity (<200 >μm) between the FBG and the microbubble resonator. The microbubble resonator is fabricated in a section of hollow-core fiber (HCF), spliced to a single-mode fiber (SMF) with a pre-inscribed FBG to form a single-ended open structure. Fresnel reflection from the HCF cleaved end means that broadband light is reflected backwards in the same direction as the Bragg wavelength from the FBG. A tapered fiber couples the reflected broadband light …

Setransformer: A Transformer-Based Code Semantic Parser For Code Comment Generation, Zheng Li, Yonghao Wu, Bin Peng, Xiang Chen, Zeyu Sun, Yong Liu, Paul Doyle

Conference Papers

Automated code comment generation technologies can help developers understand code intent, which can significantly reduce the cost of software maintenance and revision. The latest studies in this field mainly depend on deep neural networks, such as convolutional neural networks and recurrent neural network. However, these methods may not generate high-quality and readable code comments due to the long-term dependence problem, which means that the code blocks used to summarize information are far from each other. Owing to the long-term dependence problem, these methods forget the previous input data’s feature information during the training process. In this article, to solve the …

Tunable Erbium-Doped Fiber Ring Laser With A Polymer Micro Bottle Resonator, Anuradha Rout, Zhe Wang, Zhuochen Wang, Yuliya Semenova

Conference Papers

A new tunable fiber laser structure based on an erbium-doped fiber ring laser (FRL) and a polymer-based microbottle resonator (PMBR) as the wavelength selective filter is proposed and demonstrated. The tunability of the laser output in response to axial strain of up to 253.6 με applied to the PMBR is demonstrated experimentally. When the strain was applied to the PMBR’s long axis, the central lasing wavelength shifted towards shorter wavelengths in a linear fashion. The laser's strain sensitivity was determined to be 0.69 pm/με. The proposed strain-tunable PMBR laser offers the advantages of simple structure, low cost, robust performance, and …

A Robust Lpc Filtering Method For Time-Resolved Morphology Of Eeg Activity Analysis, Jin Xu, Mark Davis, Ruairí De Fréin

Conference Papers

This paper introduces a new time-resolved spectral analysis method based on Linear Prediction Coding (LPC) method that is particularly suited to the study of the dynamics of EEG (Electroencephalogram) activity. The spectral dynamic of EEG signals can be challenging to analyse as they contain multiple frequency components and are often heavily corrupted by noise. Furthermore, the temporal and spectral resolution that can be achieved is limited by the Heisenberg-Gabor uncertainty principle [1]. The method described here is based on a z-plane analysis of the poles of the LPC which allows us to identify and estimate the frequency of the dominant …

Using Bluetooth Low Energy Devices To Monitor Visitor Activity In Remote Amenity Spaces, Ahlam Al Anbouri, David Powell, Damon Berry, John Mcgrory, Niall Holmes, Lorraine D'Arcy

Conference Papers

Tracking of pedestrian behaviour, particularly route selection and temporal behaviours, can be difficult to undertake. This is especially true of studies at a community or campus level where the anonymity of pedestrians can be difficult to protect. The introduction of the EU’s General Data Protection Regulations 2016 (GDPR) has increased the complexity of this challenge. Advances in Bluetooth Low Energy (BLE) technology in recent years have increased the potential to monitor human behaviour by tracking and triangulating pedestrians. This paper describes an experiment undertaken along The Great South Wall at the Port of Dublin, which is considered a leading amenity …

Assessing The Time Synchronisation Of Eeg Systems, Yongxiang Wang, Charles Markham, Catherine Deegan

Conference Papers

This study compared the synchronisation of a medical grade Electroencephalography (EEG) system, the g.Tec, and a consumer grade EEG system, the Emotiv. Data was collected from both systems using the lab streaming layer (LSL). Both EEG systems recorded an electric signal from the surface of a customised gel phantom. The electric signal was generated using a solar cell which was illuminated by a monitor presenting a sequence of black and white images. Test results show that the g.Tec had a mean delay of 51.22 ms from the stimulus onset and the Emotiv had a mean delay of 162.69 ms from …

Mode Transition In Conventional Step-Index Optical Fibers, Xiaokang Lian, Gerald Farrell, Qiang Wu, Wei Han, Fangfang Wei, Yuliya Semenova

Conference Papers

The discrete self-imaging effect reveals the distinct properties of cladding modes with core modes in step-index optical fibers, as was shown in our previous work [1], where only the linearly polarized LP0n modes were studied. In this paper, the dispersion diagram of the first 17 vector modes (TE0n, TM0n, HEmn and EHmn) and the related first 9 LPmn modes are calculated by both the full-vector finite element method and the graphical method with a three-layer step-index optical fiber model. The cladding modes distributions and the transitions between the core and cladding modes are analyzed. The results of this work are …

Sensing Of Multiple Parameters With Whispering Gallery Mode Optical Fiber Micro-Resonators, Arun Kumar Mallik Dr, Vishnan Kavungal, Gerald Farrell, Yuliya Semenova

Conference Papers

Monitoring of multiple physical parameters, such as humidity, temperature, strain, concentrations of certain chemicals or gases in various environments is of great importance in many industrial applications both for minimizing adverse effects on human health as well as for maintaining production levels and quality of products. In this paper we demonstrate two different approaches to the design of multi-parametric sensors using coupled whispering gallery mode (WGM) optical fiber micro-resonators. In the first approach, a small array of micro-resonators is coupled to a single fiber taper, while in the second approach each of the micro-resonators within an array is coupled to …

On The Distortion Of Uwb Circularly Polarized Time-Domain Pulses In Presence Of Rotation, Adam Narbudowicz, Janusz Przewocki, Max Ammann

Conference Papers

The paper provides a first theoretical study on the effect of rotational Doppler on circularly polarized pulsed communication. Despite the circularly polarized communication being considered immune to signal fading due to rotary misalignment, such misalignment will cause a frequency-invariant phase-shift. This phase shift will significantly distort the shape of the time-domain pulse. The property can be used for integration of orientation sensing into well establish pulse-based localization. However, it has also the potential to distort communication for some pulse-modulated UWB systems.

Theoretical Analysis Of A Volume Holographic Lens Using Matlab, Sanjay Keshri, Kevin Murphy, Izabela Naydenova, Suzanne Martin

Conference Papers

Volume holographic lenses have great potential for different types of applications requiring light redirection and beam shaping such as solar light collection and LED light management. For lighting applications using LEDs, it is essential to make a highly efficient optical element to be placed in front of the LED in order to decrease energy losses. For that reason, a careful theoretical analysis of the properties and operation regime of the lens must be carried out at the design stage. The characteristics of focusing Holographic Optical Elements (HOE) depend on many factors including their thickness, spatial frequency, the angular range of …

Bluetooth Tracking Approach For User Assistance Based In Sequential Patterns Analysis., Aitor Arribas Velasco, John Mcgrory, Damon Berry

Conference Papers

As a civilization, we are drowning in a raging torrent of data, of our own making, that is being harvested by our collective technologies and systems (e.g. Fitbit, phones). However, data itself is of no utility unless it is converted into beneficial knowledge. Design patterns have been shown to be a pragmatic solution to control and manage information flows and provide order and mean-ing to data within a given context. Assisting users within their daily activities has become a key aspect for modern Artificial Intelligence Systems. Neverthe-less, although the GPS technologies work well for outside location, indoor posi-tioning is still …

Identification Of Unique Features And Exploration Of Leap Motion Controller For Detecting Hand Hygiene Stages, Rashmi Bakshi, Jane Courtney, Damon Berry, Graham Gavin

Conference Papers

Hospital acquired infections (HAIs) are contracted by the patients during the hospital stay. Antibiotic resistant microbes are the major cause and spread due to the contaminated medical equipment, crowded hospitals, frequent transfer of patients from one unit to another and poor hand hygiene. [1] In high income countries, approximately 30% of patients in intensive care units are affected by at least one HAI. [2] Hand hygiene is identified as a measure to prevent cross-transmission and to reduce the rate of HAI. [3] Technology is now used as a means of assessing hand hygiene compliance. Current approaches involve the use of …

A Comparative Study Of Chisel For Fpga Design, Paul Lennon, Richard Gahan

Conference Papers

This paper presents the results of a comparative study conducted into designing with the Chisel hardware construction language against the Verilog hardware description language across a range of standard-library and bespoke FPGA design components including an N-bit FIFO, a round-robin arbiter and a complex, scalable arbiter. Comparison metrics such as maximum operating frequency, silicon area, design flow run-time, source-code density and maintainability, simulation run-time and speed of coding are employed to evaluate the merits of designing with Chisel. Each component is implemented with a deep low-level hardware understanding with an aim to evaluate the merits of designing with Chisel from …

Validation Of Low-Cost Wireless Eeg System For Measuring Event-Related Potentials, Yongxiang Wang, Zhengwei Wang, William Clifford, Charles Markham, Tomas Ward, Catherine Deegan

Conference Papers

This study used the traditional P300 speller paradigm to compare a medical grade Electroencephalography (EEG) system, the G.Tec, with a consumer grade EEG system, the Emotiv, in the detection of P300 components within Event Related Potential (ERP) signals. The experiment focused on four electrodes known to produce optically induced visual evoked potential. A successful comparison of the two approaches was made. It was shown that both systems could measure an ERP. The paper concludes with discussion comparing the low-cost wireless EEG system with the medical grade EEG system.

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.

Fundamental Efficiency Limit Of Passive Non-Magnetic Self-Interference Suppression In Full-Duplex Radios, Adam Narbudowicz, Giuseppe Ruvio, Max Ammann, Nicola Marchetti

Conference Papers

Passive non-magnetic self-interference suppression circuits are currently used as first stages of complex full-duplex radio systems that allow simultaneous reception and transmission within the same channel. This paper introduces the upper efficiency limit for such circuitry. It is demonstrated that for these devices it is not feasible to have simultaneously high efficiency, good transmitter-to-receiver isolation and same propagation channel for transmission and reception. More specifically, the maximum efficiency for most typical case cannot exceed 50% if good isolation is obtained.

A Lightweight Classification Algorithm For Human Activity Recognition In Outdoor Spaces, Graham Mccalmont, Huiru Zheng, Haiying Wang, S. I. Mcclean, Matteo Zallio, Damon Berry

Conference Papers

The aim of this paper is to discuss the development of a lightweight classification algorithm for human activity recognition in a defined setting. Current techniques to analyse data such as machine learning are often very resource intensive meaning they can only be implemented on machines or devices that have large amounts of storage or processing power. The lightweight algorithm uses Euclidean distance to measure the difference between two points and predict the class of new records.

The results of the algorithm are largely positive achieving accuracy of 100% when classifying records taken from the same sensor position and accuracy of …

Macro, Meso And Micro Perspectives Of Technology Transfer, James A. Cunningham, Paul O'Reilly

Conference Papers

Over the last few decades research into the different aspects of technology transfer has grown significantly that has taken in the main a macro perspective. This research has created a body of knowledge and an evidence base that has contributed original insights in developing the field and also has shaped policymaking and practice. Within the field there is a growing focus on meso and micro aspects of technology transfer and a growing interest in for example role individual actors such as scientists, principal investigators policy makers, TTO actors, supporting institutions and functions such as universities, professional research organizations, technology and …

Ka-Band Vivaldi Antenna With Novel Core Element For High-Gain, Manh-Ha Hoang, Kansheng Yang, Matthias John, Patrick Mcevoy, Max Ammann

Conference Papers

A high gain Vivaldi antenna employing an integrated core element is proposed. The maximum antenna gain is 16.9 dBi and it performs better than 14 dBi over the complete Ka (24 - 40 GHz) band. The design methodology, excitation arrangement and field distribution features are described.

28 Ghz 5g Radio Over Fiber Using Uf-Ofdm With Optical Heterodyning, E Martin, C Browning, L Barry, A Farhang, L Doyle, Manh-Ha Hoang, Matthias John, Max Ammann

Conference Papers

A 5G millimeter-wave radio over fibre optical fronthaul system based on optical heterodyning, utilising an externally injected gain switched distributed feedback laser, is successfully demonstrated. Five bands of UF-OFDM are transmitted over 25 km of fibre and a 28 GHz Vivaldi Antenna wireless link. Transmission performance below the 7% FEC limit is achieved with an aggregate total data rate of 4.56 Gb/s.

High Sensitivity Refractometer Based On Reflective Smf-Small Diameter No Core Fiber Structure, Guorui Zhou, Qiang Qu, Rahul Kumar, Wai Pang Ng, Hao Liu, Longfei Niu, Nageswara Lalam, Xiaodong Yuan, Yuliya Semenova

Conference Papers

A high sensitivity refractive index sensor based on a single mode-small diameter no core fiber structure is proposed. In this structure, a small diameter no core fiber (SDNCF) used as a sensor probe, was fusion spliced to the end face of a traditional single mode fiber (SMF) and the end face of the SDNCF was coated with a thin film of gold to provide reflective light. The influence of SDNCF diameter and length on the refractive index sensitivity of the sensor has been investigated by both simulations and experiments, where results show that the diameter of SDNCF has significant influence. …

A Data Centre Air Flow Model For Predicting Computer Server Inlet Temperatures, Raymond Lloyd, Jer Hayes, Marek Rebow, Brian Norton

Conference Papers

Data centres account for approx. 1.3% 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 centre energy consumption by tackling the cooling system operations with a focus on thermal management. This work presents a novel Data Centre Air Flow Model (DCAM) for temperature prediction of server inlet temperatures. The model is a physics-based model under-pinned by turbulent jet theory allowing a reduction in the solution domain size by using only local boundary conditions in front of the servers. Current physics-based …

Calculating The Envelope Correlation Coefficient Directly From Spherical Modes Spectrum, Adam Narbudowicz, Max Ammann, R. Cornelius, D. Heberling

Conference Papers

This paper proposes an improved technique to calculate the Envelope Correlation Coefficient (ECC) by directly using the spherical mode spectrum of the antenna under test. The technique avoids errors due to numerical pattern integration and simplifies post-processing for near-field measurements. The technique is successfully tested on two different antenna types, in the total number of four MIMO configurations.

Compact Antenna For Digital Beamforming With Software Defined Radios, Adam Narbudowicz, Max Ammann, Marek Plotka, Lukasz Kulas, Krzysztof Nyka, Mateusz Rzymowski

Conference Papers

An adaptive radio system combining compact switchless reconfigurable antenna with Software Defined Radio is proposed. The system allows control of the direction of the transmitted signal solely by adjusting the baseband I and Q components of the modulated signal, while maintaining small antenna size through the use of compact multiport antenna. The system is demonstrated in a line-of-sight configuration with QPSK modulation. Experimental results demonstrate good received power and low error vector magnitude of the demodulated signals.

On The Use Of Wheeler Cap For Mimo Antennas, Florian Reher, Adam Narbudowicz, Max Ammann, Dirk Heberling

Conference Papers

A new equivalent circuit based Wheeler Cap method to calculate MIMO efficiency is introduced. The method works without the necessity for interpolation by avoiding concur of resonating and cavity modes. The method is tested with a set of three differently correlated MIMO antennas. Results are compared with the recently proposed quality factor method for MIMO antennas and efficiency data from spherical near field measurements.

Electrically Small Antenna With Switchless Pattern Reconfiguration, Adam Narbudowicz, Max Ammann, Dirk Heberling

Conference Papers

An electrically small pattern reconfigurable antenna is proposed. It allows adjustment of the radiation pattern by applying a phase shift between its two ports. The structure is a cylinder with λ/5 diameter. Simulated results show good operation at 2.44 GHz and three different radiation patterns are demonstrated by applying three different phase shifts. The antenna's principles of operation and limitations are explained based on the theory of spherical modes.

Axial Ratio Correction For Gnss Antennas In Asymetrically Coupled Environments, Adam Narbudowicz, Max Ammann, Dirk Heberling

Conference Papers

The paper demonstrates a technique to correct the axial ratio of dual-fed circularly-polarized antennas in the presence of strong coupling with surrounding components or asymmetrically reduced ground plane. It demonstrated - based on a standard GPS L1 patch antenna - that for certain situations a phase shift of up to 135° may be beneficial compared to the routinely used 90°, allowing for AR improvement from 7.8 dB (for 90°) to 2.1 dB (135°).

Easy-To-Deploy Lc-Loaded Dipole And Monopole Antennas For Cubesat, Korbinian Schraml, Adam Narbudowicz, Suramate Chalermwisutkul, Dirk Heberling, Max Ammann

Conference Papers

This paper proposes a new approach to reduce weight and complexity of VHF/UHF cubesat antennas by utilizing a dual band antenna, rather than standard two-antenna system routinely implemented in cubesats. Three systems are compared: A standard system with separate transmit/receive dipoles, a dual-band dipole for both transmit and receive and a dual-band monopole, which uses the body of 1U cubesat (10 × 10 × 10cm) as a “groundplane”. Additionally it is demonstrated that with appropriate feed the dipole might be used in monopole configuration in case of deployment system malfunction.

Hybrid Solar Thermophotovoltaic-Biomass/Gas Power Generation System With A Spectrally Matched Emitter For Lower Operating Temperatures, C. M. Iftekhar Hussain Cmih, Brian Norton, Aidan Duffy, Mohamed Oubaha

Conference Papers

Three conceptual designs have been developed for hybrid solar-biomass/gas thermophotovoltaic (TPV) system for a non-intermittent power generation which can operate at relatively low TPV operating temperatures. TPV cells with lower band gap has been chosen for this conceptual hybrid device. The low band TPV cell generates electricity at longer photonic wavelength which corresponds a lower operating temperature. The development methodology is presented for a spectrally matched emitter which emits maximum photonic energy in the 600°C -1000°C temperature range with correspondingly lower photonic energy emission in the 0°C -600°C range. This approach for spectral control in TPV systems requires fewer system …

A Dual Band 450lte/Gsm900 Pifa For Portable Devices, Abraham Loutridis, Kansheng Yang, Matthias John, Max Ammann

Conference Papers

A dual band PIFA antenna for portable devices is presented. It operates in the 450 LTE (449 − 461 MHz) and GSM 900 (876 – 922 MHz) frequency bands. The proposed antenna which has a very compact size of 7 (0.01λ0) × 7 × 70 (0.1λ0) mm3 and is suitable to integrate in small envelopes, consists of two branches and a metallic patch. The low cost and easily fabricated antenna offers high total efficiency and gain in both bands. Measured and simulated results are provided.