Miracle-dz/UniFAR-FTUs huggingface dataset:
Tunable optoelectronic oscillator working in the Ku band

An improved tunable optoelectronic oscillator (OEO) based on a dual-parallel Mach–Zehnder (MZ) modulator embedded with a sub-MZ modulator is designed and experimentally demonstrated for Ku band applications. Single-mode oscillator operation is achieved with a single feedback loop and without any electrical filters, which improves the tunability of the proposed OEO. The microwave power expression at the output of photodetector is developed using the well-known Taylor series expansion method to calculate the electrical spectrum and accumulated dispersion (ps nm−1) of the dispersive element (linearly chirped fiber Bragg grating). Phase noise is also examined, which allows us to conclude that our proposed oscillator is suitable for optical wireless communication, radar and phase array antenna applications. Furthermore, its application as a strain and temperature sensor is investigated and it is found to have maximum strain sensitivity (Kε) of 58.75 MHz με−1 and temperature sensitivity (KT) of 1.752 GHz °C−1.
Output feedback boundary control of a flexible marine riser system

This paper is concerned with the design of boundary control for globally stabilizing a flexible marine riser system. The dynamics of the riser system are represented in the form of hybrid partial–ordinary differential equations. Firstly, when the system state available for feedback is unmeasurable, an observer backstepping method is employed to reconstruct the system state and then design the boundary control for vibration suppression of the riser system. Subsequently, for the case that the system states in the designed control law cannot be accurately obtained, the high-gain observers are utilized to estimate those unmeasurable system states. With the proposed control, the uniformly ultimately bounded stability of the closed-loop system is demonstrated by the use of Lyapunov’s synthetic method and the state observer error is converged exponentially to zero as time approaches to infinity. In addition, the disturbance observer is introduced to track external environmental disturbance. Finally, the control performance of the closed-loop system is validated by carrying out numerical simulation.
An Efficient Response Distribution Function for 3D MIMO Channel Modeling from a Scatterer View

A Radio Environment Map (REM) maps its geolocation information to the propagation characteristics as complementary information for an adaptive communication of cognitive radio (CR). In this paper we propose a novel theoretical three dimension (3D) Multiple Input Multiple Output (MIMO) channel model. The proposed model parameterizes the geolocation information of interacting obstacles referred as scatterers. An efficient response distribution function (ERDF) is developed to interpolate the array response for an arbitrary scatterer location. It is shown that the mutual information of the proposed model is consistent with a conventional geometry-based model with the lower simulation time. It allows us to generate channels with all possible scatterer distribution on the surface of a building effectively.
Effect of uncertainties in sea surface temperature dataset on the simulation of typhoon Nangka (2015)

Accurate sea surface temperature (SST) datasets are critical to typhoon simulation/prediction, especially to the intensity forecast. In this study, four SST datasets were used to perform a series of experiments to examine the effects of different SST datasets and a cold SST feature on the simulation of typhoon Nangka (2015) using the Advanced Weather Research and Forecast model. Results show that the simulated typhoon intensity is very sensitive to the SST dataset used. The experiments with the SST dataset in which a cold SST feature to the south of the storm track was present/absent succeeded/failed to simulate the peak intensity and the subsequent rapid weakening of typhoon Nangka. Among the four datasets examined, only the SST dataset from the National Centers for Environmental Prediction Global Forecast System analysis captured the cold SST feature, which was likely induced by typhoon Chan‐Hom (2015) before the arrival of typhoon Nangka.
Up-regulated serum lactate dehydrogenase could become a poor prognostic marker in patients with bladder cancer by an evidence-based analysis of 2,182 patients

Background A growing number of studies have considered serum lactate dehydrogenase (LDH) as an indicator of bladder cancer (BC) prognosis. However, a meta-analysis of the serum LDH’s influence on BC prognosis is still missing. Methods PubMed, EMBASE, Web of Science and Cochrane Library were exhaustively searched for studies comparing oncological outcomes between high-LDH and low-LDH patients. Standard cumulative analyses using hazard ratios (HR) with 95% confidence intervals (CI) were performed using Review Manager (version 5.3) for overall survival (OS) in patients with BC. Results Six studies involving 2,182 patients were selected according to predefined eligibility criteria. The results showed that serum LDH level was significantly associated with OS (HR = 1.86, 95%CI = 1.54-2.25, p<0.0001) in BC. Sensitivity analysis showed the stability of the results. Subgroup analysis revealed that the levels of serum LDH had a significant impact on the OS of BC patients among different groups including publication time, research country, sample size, tumor stage, LDH cut-off value, therapy and follow-up time (all HR>1 and p<0.05), revealing that the ability of serum LDH is not affected by other factors. Conclusion Our findings indicated that a high level of serum LDH was associated with inferior OS in patients with BC. However, caution must be taken before recommendations are given because this interpretation is based upon very few clinical studies and a small sample.
The role of climatic similarity and bridgehead effects in two centuries of trade‐driven global ant invasions

International trade continues to drive biological invasions. We investigate the drivers of global nonnative ant establishments over the last two centuries using a Cox proportional hazards model. We use country‐level discovery records for 36 of the most widespread nonnative ant species worldwide from 1827 to 2012. We find that climatic similarity combined with cumulative imports during the 20 years before a species discovery in any given year is an important predictor of establishment. Accounting for invasions from both the native and previously invaded “bridgehead” regions substantially improves the model's fit, highlighting the role of spatial spillovers. These results are valuable for targeting biosecurity efforts.
Leaderless Cooperative Adaptive Cruise Control Based on the Constant Time-Gap Spacing Policy

Cooperative adaptive cruise control (CACC) in leaderless scenario is addressed in this article. The common idea in CACC is that a leader vehicle determines the steady-state speed of the platoon without considering feedback from other vehicles. The main contribution of this article is to propose a control strategy such that each vehicle in a leaderless platoon keeps a desired distance from its preceding vehicle, determined based on the constant time-gap spacing policy, and simultaneously, all the vehicles reach consensus upon their speeds. Moreover, whereas each vehicle needs access to the information of some neighboring vehicles (via a communication network) to achieve speed consensus, we assume that it has access to the relative distance of just one possible preceding vehicle (using a radar/lidar). Simulation results illustrate the performance of the proposed control strategy.
Violent Conflict and Hostility Towards Ethno-Religious Out-groups in Nigeria

Although Nigeria has a high incidence of violent conflict and is divided along ethno-religious lines, no study has, to the best of my knowledge, examined the effect of violent conflict on hostility towards ethnic and religious outgroups using representative data for Nigeria, nor the differential effects of violent conflict on outgroup hostility among Nigeria’s Muslim and Christian populations. This study does so. To measure outgroup hostility, I developed an additive indicator by combining the responses to two survey questions probing the respondents’ willingness to have people from other religions and ethnic groups as neighbors. I measured exposure to violent conflict using the total number of conflict incidents within the 30km buffer around the respondents’ dwellings. The instrumental variable regression results showed that among Nigeria’s population, violent conflict has a positive effect on outgroup hostility. A plausible mechanism through which this occurs is that violent conflict erodes trust and makes ethnic and religious fault lines salient, which in turn leads to outgroup hostility. When I broke down the data based on religious affiliation and estimated some models using the Muslim and Christian subsamples of respondents, the analysis showed that violent conflict has a positive effect on outgroup hostility among Christians. These results are robust to alternative operationalizations of outgroup hostility, different buffer sizes, and different estimation techniques. Among Muslims, violent conflict rather had a weak positive effect; however, this result was not robust to alternative operationalizations of outgroup hostility.
Modeling and performance analysis of novel quad‐tied PV array configuration under partial shading conditions

A photovoltaic (PV) cell is the smallest unit in an array that exhibits nonlinear characteristic curves. To gather the maximum amount of energy from a PV array under partial shading conditions (PSCs), it is necessary to follow the largest peak in the power–voltage (P–V) curve. PV cells are partially or totally shaded due to atmospheric conditions, which show multiple peaks in the PV curve. To overcome the losses occurring due to PSCs, PV array reconfiguration action is advisable. The authors of this work proposed a novel 5×5 $5\times 5$ quad‐tied PV array configuration and compared its performance to that of other current configurations such as series‐parallel, total‐cross tied, and others in terms of global maximum power point tracking, mismatch loss, fill factor, and efficiency. The MATLAB/Simulink 2020a platform was used to generate PV array curves under various shading conditions.
Bearing Fault Diagnosis based on Residual Network Attention Mechanism

Aiming at the problem that the detection of bearing fault diagnosis is rarely applied in the research of image classification, a new method based on residual network and attention mechanism is proposed to identify bearing fault diagnosis. One-dimensional vibration signals are transformed into two-dimensional time-frequency images by continuous wavelet transform (CWT), which are input into the model for classification. In order to solve the problem that the traditional convolutional neural network model ignores the low diagnostic accuracy of channel attention and spatial attention due to the loss of important features, the attention mechanism CBAM module is added to make up for the loss of channel features and spatial features in the traditional model. At the same time, the residual network Resnet combined with the attention mechanism can better capture the global information of the time frequency graph, and make up for the defects of the residual network module. The experimental results show that the model has high diagnostic accuracy in rolling bearing fault diagnosis, which proves that the proposed method is effective and feasible.
A Novel Orthogonal Electromagnetic Sensing Method for Metal Detection

In this article, for electromagnetic (EM) target sensing, the effect of primary- and secondary-field spatial coupling characteristics has been studied. Such investigation holds promises for metal detection. A novel orthogonal EM sensing method is proposed where the primary field is applied along the <inline-formula> <tex-math notation="LaTeX">${z}$ </tex-math></inline-formula>-axis and the secondary field is picked up along the <inline-formula> <tex-math notation="LaTeX">${x}$ </tex-math></inline-formula>-axis. When the second field is orthogonal to the primary one, the metal target incurred weak magnetic perturbation can be extracted much easier than the traditional parallel manner. Based on the theoretical analysis, a metal detection system based on a tunneling magnetoresistive (TMR) sensor and a driving coil is developed. The sensor’s sensing direction is orthogonal to the excitation field. Such metal detector has been used to detect a metal small target with increased high secondary field to the primary-field ratio (SPR) and signal-to-noise ratio (SNR) by 9.8 dB compared to the traditional parallel configuration.
Monetary Policy Shocks and Firms’ Bank Loan Expectations

We provide new evidence on how ECB’s monetary policy decisions affect firms’ bank loan expectations in the euro area. We use firm-level data derived from the ECB Survey on the Access to Finance of Enterprises for the period 2009 to 2022 and identify the impact of monetary policy by comparing the responses of firms interviewed shortly before and after monetary policy shocks. Our results are as follows. First, we find that firms’ bank loan expectations react to monetary policy, with a contractionary shock leading to a downward revision of expectations. Second, we show that firms’ response depends on the size and the sign of the shock, with only large and contractionary shocks having a significant negative effect on expectations. Third, we observe that the different components of central bank communication (i.e. the pure monetary policy shock and the central bank information shock) have different impacts on firms’ beliefs. Fourth, we find that conventional and unconventional QE shocks have opposite effects on expectations, with the impact of QE policies mainly being driven by the central bank information component of the related announcements. Finally, we document that the response to monetary policy differs along firms’ structural characteristics.
The arithmetic of maximal curves, the Hesse pencil and Mestre curve

In this thesis we study questions from a branch of mathematics called arithmetic geometry: the research on number theoretic properties of geometric objects described by algebraic equations. The first topic concerns so-called maximal curves. A curve is described by an algebraic equation in two unknowns. Solutions to the equation are called points. In our case the curve has only finitely many points. The work of Hasse, Weil and Serre provides bounds on the number of points. For a maximal curve the number of points is equal to this upper bound. We study constructions of maximal curves such that the curve remains the same, but the points are considered over varying fields. The second topic is on the Hesse pencil. This is a set of (elliptic) curves that have nine flex points in common. The set is provided with a geometric structure. We show that the structure on the flex points determines whether or not a given elliptic curve belongs to the Hesse pencil. The last topic is related to a curve introduced by Mestre. We split the so-called Jacobian variety of this curve in simple factors. In doing so, we adapt methods by Faltings and by van Wamelen to new situations.
Search for Terrestrial Gamma-ray Flashes in AGILE data by correlation with ground-based lightning measurements

Terrestrial Gamma-ray Flashes (TGFs) are sub-millisecond bursts of high energy photons, associated with lightning flashes produced inside thunderstorms. The Astro-Rivelatore Gamma a Immagini Leggero (AGILE) satellite is one of the few satellites capable of detecting these events. Comparing gamma-ray measurements by AGILE and lightning detected by the World Wide Lightning Location Network (WWLLN), it is possible to identify TGF candidates based only on time correlation between gamma-ray and lightning data. This new algorithm is not biased by previous selection criteria, e.g. spectral hardness ratio, and can therefore find new candidates which have been overlooked before. Similar procedures have already been successfully applied to data from the Fermi and RHESSI satellites. The ultimate goal is to contribute to answering the question: how common are TGFs? Using five different datasets collected by the Mini-Calorimeter (MCAL) and the Gammaray Imaging Detector (GRID), between January 2008 and April 2018, a list of new TGF candidates has been obtained. The datasets are differentiated by detector attributes and variable timing accuracy. Due to a degradation of the onboard GPS timing accuracy in July 2015, the absolute timing accuracy went from μs to ms level. By assuming perfect time correlation between the WWLLN match and the TGF, these TGF candidates are used to improve the ms timing accuracy of the AGILE data after 2015 to ∼ 100 μs. A total of 439 TGF candidates are identified in the MCAL data between 23.03. 15 14.04. 18, where 396 of them are not published before.
Enhanced radial fuzzy wavelet neural network with sliding mode control for a switched reluctance wind turbine distributed generation system

ABSTRACT In this article, an Enhanced Radial Fuzzy Wavelet Neural Network with Sliding Mode (RFWNNSM) and hill-climb searching (HCS) maximum power point tracking (MPPT) strategy are proposed for a switched reluctance generator (SRG) in a variable-speed wind energy conversion system (WECS). The implemented MPPT control is an HCS algorithm that does not require the knowledge of turbine or generator characteristics. However, this study proposes a simple optimal DC-Link voltage search type HCS control, and therefore a faster convergence to MPPT is achieved. A high-performance online training Enhanced Radial Fuzzy Wavelet Neural Network (RFWNN) using a back-propagation learning algorithm with a sliding mode regulating controller is designed for an SRG. The MPPT strategy locates the system operation points along the maximum power curves based on the DC-Link voltage of the inverter, thus avoiding the need to detect the generator speed.
GEOMETRIC STRUCTURES ON

Geometric structures on 3-manifolds are often projec- tively flat structures. Projectively flat structures on 3-manifolds are given by atlases of charts to RP 3 with projective transition maps. Equivalently, they are given by projectively flat torsion-free connections. We study the question of putting projective structures on 3-manifolds. This is done by triangulating a given 3-manifold, and then reducing the question to a 2-dimensional classical pro- jective geometry problem produced by the Haken diagram of the 3-manifold. Next, we show that the 2-dimensional problem can be reduced to solving a system of homogeneous equations that are in product forms of scalar triple products of vectors. Finally, we will compute the deformation spaces of projective structures on a small class of 3-orbifolds.
Research on Arterial Stiffness Status in Type 2 Diabetic Patients Based on Pulse Waveform Characteristics

For patients with type 2 diabetes, the evaluation of pulse waveform characteristics is helpful to understand changes in arterial stiffness. However, there is a lack of comprehensive analysis of pulse waveform parameters. Here, we aimed to investigate the changes in pulse waveform characteristics in patients with type 2 diabetes due to increased arterial stiffness. In this study, 25 patients with type 2 diabetes and 50 healthy subjects were selected based on their clinical history. Age, height, weight, blood pressure, and pulse pressure were collected as the subjects’ basic characteristics. The brachial-ankle pulse wave velocity (baPWV) was collected as an index of arterial stiffness. Parameters of time [the pulse wave period (T), the relative positions of peak point (T1) and notch point (T2), and pulse wave time difference between upper and lower limbs (T3)] and area [the total waveform area (A), and the areas of the waveform before (A1) and after (A2) the notch point] were extracted from the pulse wave signals as pulse waveform characteristics. An independent sample t-test was performed to determine whether there were significant differences between groups. Pearson’s correlation analysis was performed to determine the correlations between pulse waveform parameters and baPWV. There were significant differences in T3, A, A1, and A2 between the groups (p<0.05). For patients with type 2 diabetes, there were statistically significant correlations between baPWV and T3, A, A1, and A2 (p<0.05). This study quantitatively assessed changes in arterial pulse waveform parameters in patients with type 2 diabetes. It was demonstrated that pulse waveform characteristics (T3, A, A1, and A2) could be used as indices of arterial stiffness in patients with type 2 diabetes.
Prevalência de transtorno depressivo maior em centro de referência no tratamento de hipertensão arterial e outros fatores de risco cardiovasculares

Objetivo: Investigar a prevalencia de transtorno depressivo maior em pacientes hipertensos matriculados em um centro de referencia universitario para tratamento de hipertensao arterial e outros fatores de risco cardiovasculares. Metodos: estudo transversal, descritivo, em amostra aleatoria representativa obtida de forma sistematica de pacientes em atendimento continuo na Liga de Hipertensao Arterial da Universidade Federal de Goias. Aplicou-se o Inventario de Depressao de Beck (BDI) para rastreamento de sintomas depressivos e a entrevista estruturada SCID I/P-DSM-IV para avaliacao diagnostica de transtorno depressivo maior. Foram constituidos um grupo com pacientes portadores de depressao maior, denominado grupo estudo (GE) e um grupo com pacientes nao portadores de depressao maior, denominado grupo controle (GC). Variaveis socio-demograficas, pressao arterial e bioquimica sanguinea foram avaliadas no momento da coleta de dados. Resultados: Foram entrevistados 285 pacientes tendo sido encontrada prevalencia de 20% de depressao maior na populacao investigada. A idade media foi significativamente menor para o GE, com predominio do sexo feminino. A pratica de atividade fisica regular foi tambem significativamente menor entre os pacientes do GE que tambem apresentaram valores mais elevados de pressao arterial diastolica e de colesterolemia. Conclusao: Foi encontrada uma prevalencia de Transtorno Depressivo Maior em pacientes hipertensos superior aquela encontrada na populacao geral, alem de dados consistentes quanto a maior nivel de pressao arterial diastolica, colesterolemia e menor realizacao de atividade fisica entre individuos do Grupo Estudo. Isso aponta para uma necessidade de maior atencao para o diagnostico dos transtornos depressivos em pacientes hipertensos em atendimento primario e ambulatorial.