Miracle-dz/UniFAR-FTUs huggingface dataset:
Sensitivity enhancement of super resolution breast tumour imaging with far-field time reversal mirror integrating with multi-layered sub-wavelength patch scatterers

We present numerical simulation study of super-resolution imaging of closely spaced sub-wavelength size breast tumours with low cost microwave MIMO bowtie antenna array integrating with near-field planar multi-layered sub-wavelength patch (MLSWP) scatterers by using a monopole as the excitation source. The MLSWP scatterers, serving as transforming structures for the propagation of evanescent waves for sub-wavelength breast tumours imaging with far-field time reversal technique incorporating with bowtie antenna time reversal mirror, are investigated in this paper. The use of the MLSWP scatterers has enhanced the directivity and gain of the traditional monopole resulting in the enhanced scattering amplitudes of the tumour inclusions in the breast. The scattering intensity of the tumours has been enhanced as compared to imaging without the MLSWP scatterers. We propose a tumour imaging scheme using a bowtie antenna array with far-field electromagnetic time reversal for which tumours of sub-wavelength dimensions of 2 mm, 4 mm and 6 mm at sub-wavelength inter tumour distances have been imaged from our simple breast model with super-resolution operating at 2.45 GHz. This will greatly enhance the early imaging of breast tumours in the fight against breast cancer whiles attaining a cost effective biomedical imaging system since the antennas and MLSWP scatterers are low cost microwave components.
A Local Adaptive Minority Selection and Oversampling Method for Class-Imbalanced Fault Diagnostics in Industrial Systems

Data-driven fault diagnostics of industrial systems suffer from class-imbalanced problems, which is a common challenge for machine learning algorithms as it is difficult to learn the features of the minority class samples. Synthetic oversampling methods are commonly used to tackle these problems by generating minority class samples to balance the majority and minority classes. Two major issues will influence the performance of oversampling methods which are how to choose the most appropriate existing minority seed samples, and how to synthesize new samples from seed samples effectively. However, many existing oversampling methods are not accurate and effective enough to generate new samples when dealing with high-dimensional faulty samples with different imbalanced ratios, since they do not take these two factors into consideration at the same time. This article develops a novel adaptive oversampling technique: expectation maximization (EM)-based local-weighted minority oversampling technique for industrial fault diagnostics. This method uses a local-weighted minority oversampling strategy to identify hard-to-learn informative minority fault samples and an EM-based imputation algorithm to generate fault samples based on the distribution of minority samples. To validate the performance of the developed method, experiments were conducted on two real-world datasets. The results show that the developed method can achieve better performances, in terms of F-measure, Matthews correlation coefficient (MCC), and Mean (average of F-measure and MCC) values, on multiclass imbalanced fault diagnostics in different imbalance ratios than state-of-arts’ baseline sampling techniques.
New design of adaptive Gabor wavelet filter bank for medical image retrieval

Gabor wavelet is widely used in the analysis of texture feature. This study presents a novel feature descriptor based on the design of adaptive Gabor wavelet filter-bank for medical image retrieval. The design of proposed Gabor wavelet provides flexibility to extract the dominant directional features from medical images. First, peaks in the spectrum of medical image are analysed to determine the dominant directions present in the image. With these dominant directions, a bank of Gabor-filters is designed to extract the directional features effectively. Next, feature vector is derived by computing the energy and standard deviation from the Gabor filtered coefficients at a particular scale and orientation. The use of maximum likelihood estimation (MLE) is suggested to measure the similarity between the feature vectors of heterogeneous medical images. The performance of the proposed method is evaluated on three different publicly available databases namely NEMA, OASIS and EXACT09. The performance in terms of average retrieval precision (ARP), average retrieval rate (ARR) and computational time are compared with well-known existing methods. It is observed from experimental results that the proposed approach achieved ARP of 85.32, 85.24 and 77% and ARR of 31.33, 14.05 and 23.78% for NEMA, OASIS and EXACT09 databases respectively.
Understandings of Classical and Incremental Backstepping Controllers With Model Uncertainties

This article suggests closed-loop analysis results for both classical and incremental backstepping controllers considering model uncertainties. First, transfer functions with each control algorithm under the model uncertainties, are compared with the ones for the nominal case. The effects of the model uncertainties on the closed-loop systems are critically assessed via investigations on stability conditions and performance metrics. Second, closed-loop characteristics with classical and incremental backstepping controllers under the model uncertainties are directly compared using derived common metrics from their transfer functions. This comparative study clarifies how the effects of the model uncertainties on the closed-loop system become different depending on the applied control algorithm. It also enables an understanding of the effects of additional measurements in the incremental algorithm. Third, case studies are conducted assuming that the uncertainty exists only in one aerodynamic derivative estimate while the other estimates have true values. This facilitates systematic interpretations on the impacts of the uncertainty on the specific aerodynamic derivative estimate to the closed-loop system.
Advancing the matter bispectrum estimation in large-scale structure

My PhD was generously funded by the Cambridge Commonwealth, European and International Trust and the Croucher Foundation. I have additionally received invaluable financial assistance from St. Catharine's College, Cambridge, the Cambridge Philosophical Society, the Department of Applied Mathematics and Theoretical Physics, and the Centre for Theoretical Cosmology in my final year.
Divide and Extract – Disentangling Clause Splitting and Proposition Extraction

Proposition extraction from sentences is an important task for information extraction systems Evaluation of such systems usually conflates two aspects: splitting complex sentences into clauses and the extraction of propositions. It is thus difficult to independently determine the quality of the proposition extraction step. We create a manually annotated proposition dataset from sentences taken from restaurant reviews that distinguishes between clauses that need to be split and those that do not. The resulting proposition evaluation dataset allows us to independently compare the performance of proposition extraction systems on simple and complex clauses. Although performance drastically drops on more complex sentences, we show that the same systems perform best on both simple and complex clauses. Furthermore, we show that specific kinds of subordinate clauses pose difficulties to most systems.
The failure of the balanced condition in the natural experiment design

An important task in economics and finance studies involves establishing causal inference. Given the obstacles in obtaining reliable instrumental variables, such methodologies as the ordinary least squares (OLS)—which is used in natural experiment, as it takes advantage of exogenous events—have become prominent without questioning the balanced condition hypothesis. One empirical problem with such methodologies is that the treatment assignment is not random and is characterized by non-balanced covariates across the treatment and control groups. This problem is often not obvious to researchers, and they may infer causality where none may exist. By employing examples from influential journals, we demonstrate that natural experiment studies’ causal inferences may change after we address all problematic imbalanced conditions. We argue that data quality will affect estimates of the treatment effect: specifically, a well-balanced dataset will require fewer matching activities, the estimation results after addressing the problematic imbalance become less volatile in a better-balanced dataset compared with those from a low-quality dataset. Our results suggest that relying on natural experiment to obtain causal effect may understate the potential bias caused from non-randomness assumption.
In‐Plane Photonic Crystal Devices using Fano Resonances

Nanocavity devices enabling concentration of light in a very small volume have resulted in several interesting applications over the past years. Of particular interest are the asymmetric resonance lineshapes known as Fano resonances, which result from the interference between a discrete mode of the nanocavity and a continuum of background modes. Compared to the conventional symmetric Lorentzian lineshape, asymmetric Fano lineshapes enable novel or improved device structures for use in optical switches, sensors, lasers, and narrow band filters. Herein, the use of Fano lineshapes in photonic crystal membranes for realizing various optical signal processing functionalities is reviewed. The basic theory of Fano resonances is presented, different photonic crystal Fano device geometries are discussed, the nonlinear processes empowering the devices are explained, and an overview of all‐optical signal processing demonstrations based on Fano resonances is given.
Constraining Planetary Gas Accretion Rate from Hα Line Width and Intensity: Case of PDS 70 b and c

Recent observations of protoplanets embedded in circumstellar disks have shed light on the planet formation process. In particular, detection of hydrogen Balmer-line (Hα) emission gives direct constraints on late-stage accretion onto gas giants. Very recently Haffert et al. measured the spectral line widths, in addition to intensities, of emission from the two protoplanets orbiting PDS 70. Here, we study these protoplanets by applying radiation-hydrodynamic models of the shock-heated accretion flow onto protoplanets that Aoyama et al. have recently developed. As a result, we demonstrate that Hα line widths combined with intensities lead to narrowing down the possible ranges of the protoplanetary accretion rate and/or mass significantly. While the current spectral resolution is not high enough to derive a definite conclusion regarding their accretion process, high-resolution spectral imaging of growing protoplanets is highly promising.
Effects of non-equilibrium excitation on methane oxidation in a low-temperature RF discharge

The kinetic effects of non-equilibrium excitation by direct electron impact on low-temperature oxidation of CH4 were investigated by experiment and simulation. We focused on the vibrational-electronic-chemistry coupling of methane and oxygen molecules under conditions of immediate reduced electric field strengths of 30–100 Td in an RF dielectric barrier discharge. A detailed plasma chemistry mechanism governing the oxidation processes in an He/CH4/O2 combustible mixture was proposed and studied by including a set of electron impact reactions, dissociative recombination reactions, reactions involving vibrationally- and electronically- excited species, and important three-body recombination reactions. A linear increase in reactant consumption with an increase in plasma power was observed experimentally. This suggested the presence of decoupling between the molecular excitation by plasma and the low-temperature chemistry. However, CO formation showed a non-linear trend, with its formation increasing with lower energy inputs and decreasing at higher energy inputs. By modelling the chemical kinetic sensitivity and reaction pathways, we found that the formation of radicals via the chain propagation reactions CH4 + O(1D) → CH3 + OH, and O2(a1Δg) + H → O + OH was mainly accelerated by the electronically excited species O(1D) and O2(a1Δg). The numerical simulation also revealed that under conditions of incomplete relaxation, the vibrational species CH4(v) and O2(v) enhanced chain propagating reactions, such as CH4(v) + O → CH3 + OH, CH4(v) + OH → CH3 + H2O, O2(v) + H → O + OH, thus stimulating the production of active radicals and final products. Specifically, for an E/N value of 68.2 Td in a stoichiometric mixture (0.05 CH4/0.1 O2/0.85 He), O(1D), CH4(v13), and O2(v) were estimated to contribute to 12.7%, 3.6%, and 3.8% of the production of OH radicals respectively. The reaction channel CH4(v13) + OH → H2O + CH3 was estimated to be responsible for 1.6% of the H2O formation. These results highlight the strong roles of vibrational states in a complex plasma chemistry system and provide new insights into the roles of excited species in the low-temperature oxidation kinetics of methane.
Aperture coupling rectangular slotted circular ring microstrip patch antenna

This paper designed circular ring microstrip patch antenna using aperture coupling feeding techniques with rectangular slots on the patch for LTE. The use of aperture coupling feeding techniques were expected to optimize antenna parameters performance. The addition of rectangular slots on the patch produced multi resonant frequencies than the original characteristics. The simulated optimized design generated 1.8 GHz, 2.1 GHz, and 2.72 GHz with Return Loss value -22.3683 dB, -18.8133 dB, -24.3451 dB and VSWR value 1.1648, 1.259, 1.1291. Meanwhile, the measurement results of fabricated antenna showed the frequency produced by the antenna was 1.8 GHz with value of Return Loss and VSWR -18.257 dB and 1.278 in a reference value of VSWR < 2 and Return Loss < -10 dB.
K-Nearest Neighbor for colon cancer identification

Colon cancer or colorectal cancer is a type of cancer that attacks the last part of the human digestive system. Lymphoma and carcinoma are types of cancer that attack humans colon. Colon cancer causes deaths about half a million people every year. In Indonesia, colon cancer is the third largest cancer case for women and second in men. Unhealthy lifestyles such as minimum consumption of fiber, rarely exercising and lack of awareness for early detection are factors that cause high cases of colon cancer. The aim of this study is to produce a system that can detect and classify images into type of colon cancer lymphoma, carcinoma, or normal. The designed system used 198 data colon cancer tissue pathology, consist of 66 images for Lymphoma cancer, 66 images for carcinoma cancer and 66 for normal/healthy colon condition. This system will classify colon cancer starts from image preprocessing, feature extraction using Principal Component Analysis (PCA) and classification using K-Nearest Neighbor (K-NN) method. Several stages in preprocessing are resized, convert RGB image to grayscale, edge detection, and last histogram equalization. Tests will be done by trying some K-NN input parameter settings. The result of this study is an image processing system that can detect and classify type of colon cancer with high accuracy and low computation time.
PENENTUAN KADAR LOGAM BERAT (As, Ba, Cd, Cr, Hg, Pb, Sb, Se) PADA MAINAN ANAK DENGAN METODE SNI ISO 8124-3:2010 MENGGUNAKAN ICP-OES

Keamanan mainan anak merupakan faktor penting yang harus diperhatikan. Salah satunya adalah dengan melihat ada atau tidaknya kandungan logam berat seperti Arsenik, Barium, Kadmium, Kromium, Merkuri, Timbal, Antimoni dan Selenium pada mainan tersebut. Logam berat bersifat karsinogenik dan menjadi penyebab berbagai penyakit maupun keracunan. Analisa kandungan logam berat dapat dilakukan dengan metode yang telah terverifikasi yaitu SNI ISO 8124-3 : 2010. Preparasi sampel dilakukan dengan metode destruksi basah yang berfungsi mendekomposisi padatan dari analit. Variasi jenis bahan mainan juga perlu dilakukan untuk melihat perbedaan hasil analisa. Sedangkan ukuran partikel sampel juga dapat berpengaruh pada hasil analisa. Instrumen ICP-OES (Inductively Coupled Plasma-Optical Emission Spektrofotometry) dipilih karena memiliki batas deteksi yang rendah untuk hampir seluruh elemen, selektifitasnya sangat tinggi, ketepatan presisi dan akurasi, serta waktu pengukuran yang relatif singkat. Sistem instrumen menggunakan plasma sebagai pengionisasi dan Argon sebagai gas pembawa. Dari hasil analisa dapat disimpulkan bahwa dalam sampel mainan yang diuji, tidak terdapat kandungan logam Ba, Cd, Cr, Se. Sedangkan untuk logam As, Hg, Pb, Sb menunjukan adanya kandungan logam tersebut di dalam mainan yang diuji, yaitu berada pada kisaran 0,6 - 6,4 mg/kg. Angka masih berada di bawah ambang batas maksimal yang diperbolehkan dalam SNI ISO 8124-3 : 2010.
Design and Fabrication of an Efficient Metallic Phased Array for TACAN Application

We propose a wideband, low-loss, low-cost, and high-gain metallic phased array for tactical air navigation (TACAN) systems. Such an array composed of 12 slot patch antennas with an air substrate. The element of this array has been optimized for working in 950 ~ 1250 MHz with a gain of 9 dBi. For using such an array in the TACAN system, an iterative method is utilized for synthesizing a cosecant-squared pattern (CSP). This method optimizes the element excitation in a linear phased array and allows having fewer ripples in the shaped region and lower sidelobe level (SLL). The obtained excitations by means of this method are realized using an all-metal feed network. Such a feed structure does not use any phase shifter and its dimensions are optimized on the air substrate to operate in the wideband frequency range and to be a low-loss and low-cost structure. To validate the numerical and analytical results, the entire system, i.e., the antenna array along with its feed network, is fabricated and successfully measured. The measurements on a 180 cm <inline-formula> <tex-math notation="LaTeX">$\times24$ </tex-math></inline-formula> cm array and 550 mm <inline-formula> <tex-math notation="LaTeX">$\times350$ </tex-math></inline-formula> mm feed network show a CSP with a maximum gain of 12.4 dBi and SLL <−23 dB at the central frequency of TACAN bandwidth (962 ~ 1213 MHz).
Auditor Product and Controller Synthesis for Nondeterministic Transition Systems With Practical LTL Specifications

Controller design for continuous systems with linear temporal logic (LTL) specifications is a computationally intensive task. Abstracting a discrete transition system from a real-world continuous-state system often results in a state machine with a large number of states and nondeterministic transitions. This makes controller synthesis for LTL specifications difficult specially when the design specification is lengthy. To reduce the complexity, we consider the specifications that are in the conjunctive form of practical LTL patterns. We use <italic>auditor product</italic> to incrementally restrict the system to satisfy the safety part of each subspecification. The control strategy, that satisfies the liveness part is then calculated by solving a generalized Buchi game on the result of the auditor product of the discrete transition system with all subspecifications. This approach has the same worst case computational complexity as <inline-formula><tex-math notation="LaTeX">$\text{GR}(1)$</tex-math></inline-formula> synthesis, but avoids some of the fundamental limitations involved with <inline-formula><tex-math notation="LaTeX">$Assumption \Rightarrow Guarantee$</tex-math></inline-formula> formulation of the problem.
Universal formulation of central-moments-based lattice Boltzmann method with external forcing for the simulation of multiphysics phenomena

The cascaded or central-moments-based lattice Boltzmann method (CM-LBM) is a robust alternative to the more conventional Bhatnagar-Gross-Krook-LBM for the simulation of high-Reynolds number flows. Unfortunately, its original formulation makes its extension to a broader range of physics quite difficult. In addition, it relies on CMs that are derived in an ad hoc manner, i.e., by mimicking those of the Maxwell-Boltzmann distribution to ensure their Galilean invariance a posteriori. This work aims at tackling both issues by deriving Galilean invariant CMs in a systematic and a priori manner, thanks to the Hermite polynomial expansion framework. More specifically, the proposed formalism fully takes advantage of the D3Q27 discretization by relying on the corresponding set of 27 Hermite polynomials (up to the sixth-order) for the derivation of both the discrete equilibrium state and the forcing term in an a priori manner. Furthermore, while keeping the numerical properties of the original CM-LBM, this work leads to a compact and simple algorithm, representing a universal methodology based on CMs and external forcing within the lattice Boltzmann framework. To support these statements, mathematical derivations and a comparative study with four other forcing schemes are provided. The universal nature of the proposed methodology is eventually proved through the simulation of single phase, multiphase (using both pseudopotential and color-gradient formulations), and magnetohydrodynamic flows.The cascaded or central-moments-based lattice Boltzmann method (CM-LBM) is a robust alternative to the more conventional Bhatnagar-Gross-Krook-LBM for the simulation of high-Reynolds number flows. Unfortunately, its original formulation makes its extension to a broader range of physics quite difficult. In addition, it relies on CMs that are derived in an ad hoc manner, i.e., by mimicking those of the Maxwell-Boltzmann distribution to ensure their Galilean invariance a posteriori. This work aims at tackling both issues by deriving Galilean invariant CMs in a systematic and a priori manner, thanks to the Hermite polynomial expansion framework. More specifically, the proposed formalism fully takes advantage of the D3Q27 discretization by relying on the corresponding set of 27 Hermite polynomials (up to the sixth-order) for the derivation of both the discrete equilibrium state and the forcing term in an a priori manner. Furthermore, while keeping the numerical properties of the original CM-LBM, this work lead.