A new noise metric has been developed that may be used for optimization problems involving aerodynamic noise from a clean wing. The modeling approach uses a classical trailing edge noise theory as the starting point. The final form of the noise metric includes characteristic velocity and length scales that are obtained from three-dimensional, steady, RANS simulations with a two- equation k-omega turbulence model. The noise metric is not the absolute value of the noise intensity, but an accurate relative noise measure as shown in the validation studies. One of the unique features of the new noise metric is the modeling of the length scale, which is directly related to the turbulent structure of the flow at the trailing edge. The proposed noise metric model has been formulated so that it can capture the effect of different design variables on the clean wing airframe noise such as the aircraft speed, lift coefficient, and wing geometry. It can also capture three-dimensional effects which become important at high lift coefficients, since the characteristic velocity and the length scales are allowed to vary along the span of the wing. Noise metric validation was performed with seven test cases that were selected from a two-dimensional NACA 0012 experimental database. The agreement between the experiment and the predictions obtained with the new noise metric was very good at various speeds, angles of attack, and Reynolds Number, which showed that the noise metric is capable of capturing the variations in the trailing edge noise as a relative noise measure when different flow conditions and parameters are changed. Parametric studies were performed to investigate the effect of different design variables on the noise metric. Two-dimensional parametric studies were done using two symmetric NACA four-digit airfoils (NACA 0012 and NACA 0009) and two supercritical (SC(2)-0710 and SC(2)-0714) airfoils. The three-dimensional studies were performed with two versions of a conventional transport wing at realistic approach conditions. The twist distribution of the baseline wing was changed to obtain a modified wing which was used to investigate the effect of the twist on the trailing edge noise. An example study with NACA 0012 and NACA 0009 airfoils demonstrated a reduction in the trailing edge noise by decreasing the thickness ratio and the lift coefficient, while increasing the chord length to keep the same lift at a constant speed. Both two- and three-dimensional studies demonstrated that the trailing edge noise remains almost constant at low lift coefficients and gets larger at higher lift values. The increase in the noise metric can be dramatic when there is separation on the wing. Three-dimensional effects observed in the wing cases indicate the importance of calculating the noise metric with a characteristic velocity and length scale that vary along the span. The twist change does not have a significant effect on the noise at low lift coefficients, however it may give significant noise reduction at higher lift values. The results obtained in this study show the importance of the lift coefficient on the airframe noise of a clean wing and favors having a larger wing area to reduce the lift coefficient for minimizing the noise. The results also point to the fact that the noise reduction studies should be performed in a multidisciplinary design and optimization framework, since many of the parameters that change the trailing edge noise also affect the other aircraft design requirements. It's hoped that the noise metric developed here can aid in such multidisciplinary design and optimization studies. / Ph. D.

The flow over sharp-edged wings is almost always separated. The control of separated flows is possible and benefits can be achieved but only in a time average sense. A new design of an actuator was designed and tested which can achieve a wide range velocity of without frequency dependence, is free of oscillating components as well as free of secondary frequencies and therefore can be scaled up easily, unlike a traditional synthetic jet. The actuator can achieve a considerable amount of jet vectoring, thus aligning the disturbance with the leading edge shear layer. Results indicate that unsteady mini-jet actuation is an effective actuation device capable of increasing the lift in the stall region of the airfoil. Moreover, pressure measurements showed that two parameters could be altered to maximize the lift. The momentum coefficient needed a minimum value to exert influence and the actuating frequency need not be at exact the natural shedding frequency to improve the lift and can be operated at harmonics of the natural shedding frequency and obtain improvements. / Master of Science

Bolometers are the most sensitive detectors for measuring millimeter and submillimeter wavelength astrophysical signals. Cameras comprised of arrays of bolometers have already made significant contributions to the field of astronomy. A challenge for bolometer cameras is obtaining observations at multiple wavelengths. Traditionally, observing in multiple bands requires a partial disassembly of the instrument to replace bandpass filters, a task which prevents immediate spectral interrogation of a source. More complex cameras have been constructed to observe in several bands using beam splitters and dichroic filters, but the added complexity leads to physically larger instruments with reduced efficiencies. The SPEctral Energy Distribution camera (SPEED) is a new type of bolometer camera designed to efficiently observe in multiple wavebands without the need for excess bandpass filters and beam splitters. SPEED is a ground-based millimeter-wave bolometer camera designed to observe at 2.1, 1.3, 1.1, and 0.85 mm simultaneously. SPEED makes use of a new type of bolometer, the frequency selective bolometer (FSB), to observe all of the wavebands within each of the camera's four pixels. FSBs incorporate frequency selective dipole surfaces as absorbing elements allowing each detector to absorb a single, narrow band of radiation and pass all other radiation with low loss. Each FSB also contains a superconducting transition-edge sensor (TES) that acts as a sensitive thermistor for measuring the temperature of the FSB. This thesis describes the development of the SPEED camera and FSB detectors. The design of the detectors used in the instrument is described as well as the the general optical performance of frequency selective dipole surfaces. Laboratory results of both the optical and thermal properties of millimeter-wave FSBs are also presented. The SPEED instrument and its components are highlighted and the optical design of the optics which couple SPEED to the Heinrich Hertz Telescope is given. This thesis concludes with an introduction to the jiggle mapping data analysis of bolometer instruments like SPEED.

In this thesis, we study the unconventional superconductivity in Sr2RuO4 (SRO) and related systems. The superconducting state in SRO remains a puzzle after more than 28 years of study. Early experiments had pointed toward a topological non-trivial time-reversal symmetry breaking (TRSB) chiral p-wave order. This pairing candidate has attracted a large amount of attention, partly in relation to the possibility of topological quantum computation, and has stimulated studies on higher chirality superconducting systems. In the first part of this thesis, we study the spontaneous edge current in chiral d- and f-wave superconductors. We show that these currents, which vanish in the continuum limit at zero temperature, are generally non-vanishing but tiny, compared to the simplest chiral p-wave case. In the presence of strong surface roughness, the direction of the edge current in the chiral d-wave case can be reversed, compared with that of a specular ideal surface with specular scattering. However, it is shown that this current reversal is non-universal beyond the continuum limit. The chiral p-wave scenario in SRO is overturned by recent Knight shift measurements, highlighting the importance of exploring different pairing symmetries for SRO. Recently, $d_{x^2-y^2} \pm ig_{(x^2-y^2)xy}$, $s' \pm id_{xy}$ and mixed helical p-wave pairings have been proposed as order parameter candidates. However, the stability of these states, especially of the $d_{x^2-y^2} \pm ig$ pairing, remains unclear. In the second part of the thesis, we study the leading superconducting instabilities in SRO in the presence of sizable atomic spin-orbit coupling (SOC), non-local SOC, and non-local interactions. We find that it is difficult to stabilize chiral p-wave pairing in SRO models; this is because, among the triplet p-wave states, the atomic SOC favors helical states over the chiral state. The presence of both d- and g-wave pairings, including a $d_{x^2-y^2} \pm ig$ state, is found when the second nearest neighbor (in-plane) repulsions, together with orbital-anisotropy of the non-local interactions and/or the B2g channel non-local SOC are included. We further analyze the properties, such as nodal structures, in-plane field spin-susceptibility, and spontaneous edge current, of the realized $d_{x^2-y^2} \pm ig$ pairing and find that this state is more compatible with existing experimental measurements than the $s' \pm id_{xy}$ and the mixed helical p-wave proposals. / Dissertation / Doctor of Philosophy (PhD)

Wireless, Edge-based control and 5G networks are all examples of technologies of the emerging Industry 4.0. Understanding and evaluating these technologies is important to the development of future manufacturing and factories. However, moving from classical, wired control systems to wireless and Edge-based systems comes with new challenges such as communication delays and packet losses. The purpose of this thesis is to develop and evaluate the performance of a wireless 5G and Edge-based control system. Firstly, we aim to find the achievable end-to-end latency of three different network architectures: local control, control over wired Ethernet and control over wireless 5G. Secondly, we propose and test a conservative tuning approach on a Ball and Beam process which represents a time-sensitive and mission-critical process. The proposed conservative tuning approach is based on an Internal Model Control framework which enables an adjustment of the controller parameters based onthe worst-case measured latency. The results show that the measured latency increases as the Task interval time is increasing and as the controller is moving further away from a local level. The results also show that the introduced latency over 5G is making the system unstable if the latency is not taken into account in the design. The proposed conservative tuning approach successfully adjusts the parameters to remove this unstable behavior but degrades the control performance and shows signs of an overly conservative tuning compared to a local controller. The thesis concludes that the proposed conservative tuning approach shows promising results but would benefit from being further developed towards a latency-aware controller. This could be achieved by firstly improving the way latency is measured to enable extensive data collection. The data could then be utilized by using machine learning or time-series to predict the latency and adjust the parameters in real-time, using the proposed tuning approach.

京都大学 / 新制・課程博士 / 博士(情報学) / 甲第24261号 / 情博第805号 / 新制||情||136(附属図書館) / 京都大学大学院情報学研究科社会情報学専攻 / (主査)教授 伊藤 孝行, 教授 吉川 正俊, 教授 神田 崇行, 特定准教授 LIN Donghui / 学位規則第4条第1項該当 / Doctor of Informatics / Kyoto University / DFAM

<p>This thesis reports work targeting the integration of Si light emitters with optical waveguides. Such integrated devices would find utility in a number of applications including telecommunications, optical interconnects, and biological and chemical sensors. Much research has been directed by others on how to improve the emission efficiency and achieve lasing in VLSI (very large scale integration) compatible sources. Here, the focus is on how such devices can be integrated with planar waveguides. Two enhancement techniques were selected for potential integration; defect engineering (DE), and Si nanocrystals (Si-nc) embedded in Si02• Defect engineered light emitting diodes (LEDs) made on silicon-on-insulator (SOI) and emitting at 1.1 μm were successfully demonstrated. In addition, surface photoluminescence from SOI was analyzed to account for interference from the SOI cavity. However, it was determined that the emission efficiency of defect engineered LEDs studied during the course of this work is below that which was reported previously, and that the fabrication procedure thus suffers from irreproducibility. Barring an enormous advancement in the DE technique, it is concluded that the emission efficiency is too small to make use of its integration potential. </p><p>A more successful approach was obtained from the Si-nc system fabricated using electron-cyclotron resonance plasma enhanced chemical vapor deposition (ECR-PECVD). Optically pumped edge emitting devices were designed, fabricated and characterized. The devices are comprised of Si-ncs emitting at 800 nm, integrated with slab silicon nitride waveguides. This work is the first report of edge emission from Si-ncs integrated with silicon nitride waveguides. Edge emission and waveguide properties were characterized in the ~850 nm emission band of the Si-ncs. The edge emission was well described as a propagating mode, attenuated primarily by the Si-nc film. Propagation losses of a typical air/Si-nc/SiNx/Si02 waveguide were measured to be 11 ± 2 dB/cm and 20 ± 2 dB/cm at 850 nm in the TE and TM polarizations respectively. A wavelength dependent loss of -0.14 ± 0.03 dB/(cm*nm) was found to exist in the material loss of Si-nc films. In addition, the Si-nc films were found to undergo a partially recoverable photo-induced degradation of PL efficiency during exposure to pump light. Processing techniques compatible with both high efficiency Si-nc and low loss silicon nitride were developed and described. A two-sectioned photonic device was also designed, fabricated and characterized. The device contained an optically pumped Si-nc emitting waveguide section integrated with a low loss silicon nitride slab waveguide. The potential for optically pumped Si-nc emitters integrated with silicon nitride photonic circuits thus appears promising.</p> / Thesis / Doctor of Philosophy (PhD)

We reserve the first part of this thesis to a brief (and by far incomplete, but hopefully self-contained) introduction to the vast subject of quantum Hall physics. We dedicate the first chapter to a discursive broad introduction. The second one is instead used to introduce the integer and fractional quantum Hall effects, with an eye to the synthetic quantum matter platforms for their realization. In the third chapter we present famous Laughlin's wavefunction and discuss its basic features, such as the gapless edge modes and the gapped quasiparticle excitations in the bulk. We close this introductory part with a fourth chapter which presents a brief overview on the chiral Luttinger liquid theory. In the second part of this thesis we instead proceed to present our original results. In the fifth chapter we numerically study the linear and non-linear dynamics of the chiral gapless edge modes of fractional quantum Hall Laughlin droplets -- both fermionic and bosonic -- when confined by anharmonic trapping potentials with model short range interactions; anharmonic traps allow us to study the physics beyond Wen's low-energy/long-wavelength chiral Luttinger liquid paradigm in a regime which we believe is important for synthetic quantum matter systems; indeed, even though very successful, corrections to Wen's theory are expected to occur at higher excitation energies/shorter wavelengths. Theoretical works pointed to a modified hydrodynamic description of the edge modes, with a quadratic correction to Wen's linear dispersion $\omega_k=vk$ of linear waves; even though further works based on conformal field theory techniques casted some doubt on the validity of the theoretical description, the consequences of the modified dispersion are very intriguing. For example, in conjunction with non-linearities in the dynamics, it allowed for the presence of fractionally quantized solitons propagating ballistically along the edge. The strongly correlated nature of fractional quantum Hall liquids poses technical challenges to the theoretical description of its dynamics beyond the chiral Luttinger liquid model; for this reason we developed a numerical approach which allowed us to follow the dynamics of macroscopic fractional quantum Hall clouds, focusing on the neutral edge modes that are excited by applying an external weak time-dependent potential to an incompressible fractional quantum Hall cloud prepared in a Laughlin ground state. By analysing the dynamic structure factor of the edge modes and the semi-classical dynamics we show that the edge density evolves according to a Korteweg-de Vries equation; building on this insight, we quantize the model obtaining an effective chiral Luttinger liquid-like Hamiltonian, with two additional terms, which we believe captures the essential low-energy physics of the edge beyond Wen's highly successful theory. We then move forward by studying -- even though only partially -- some of the physics of this effective model and analyse some of its consequences. In the sixth chapter we look at the spin properties of bulk abelian fractional quantum Hall quasiparticles, which are closely related to their anyonic statistics due to a generalized spin-statistics relation - which we prove on a planar geometry exploiting the fact that when the gauge-invariant generator of rotations is projected onto a Landau level, it fractionalizes among the quasiparticles and the edge. We then show that the spin of Jain's composite fermion quasielectron satisfies the spin-statistics relation and is in agreement with the theory of anyons, so that it is a good anti-anyon for the Laughlin's quasihole. On the other hand, even though we find that the Laughlin’s quasielectron satisfies the spin-statistics relation, it carries the wrong spin to be the anti-anyon of Laughlin’s quasihole. Leveraging on this observation, we show how Laughlin's quasielectron is a non-local object which affects the system's edge and thus affecting the fractionalization of the spin. Finally, in the seventh chapter we draw our conclusions.

No description available.

The prominence of Edge Machine Learning is increasing swiftly as the performance of microcontrollers continues to improve. By deploying object detection and classification models on edge devices with camera sensors, it becomes possible to locate and identify objects in their vicinity. This technology finds valuable applications in wildlife conservation, particularly in camera traps used in African sanctuaries, and specifically in the Ngulia sanctuary, to monitor endangered species and provide early warnings for potential intruders. When an animal crosses the path of a an edge device equipped with a camera sensor, an image is captured, and the animal's presence and identity are subsequently determined. The performance of three distinct object detection models: SSD MobileNetV2, FOMO MobileNetV2, and YOLOv5 is evaluated. Furthermore, the compatibility of these models with three different microcontrollers ESP32 TimerCam from M5Stack, Sony Spresence, and LILYGO T-Camera S3 ESP32-S is explored. The deployment of Over-The-Air updates to edge devices stationed in remote areas is presented. It illustrates how an edge device, initially deployed with a model, can collect field data and be iteratively updated using an active learning pipeline. This project evaluates the performance of three different microcontrollers in conjunction with their respective camera sensors. A contribution of this work is a successful field deployment of a LILYGO T-Camera S3 ESP32-S running the FOMO MobileNetV2 model. The data captured by this setup fuels an active learning pipeline that can be iteratively retrain the FOMO MobileNetV2 model and update the LILYGO T-Camera S3 ESP32-S with new firmware through Over-The-Air updates. / Project Ngulia