Miracle-dz/UniFAR-FTUs huggingface dataset:
High/ultra-high dimensional single-index models

Single-index models are useful and fundamental tools for handling “curse of dimensionality” problems in nonparametric regression. In addition to that, variable selection also plays an important role in such model building processes when the index vectors are high-dimensional. Several procedures have been developed for estimation and variable selection for single-index models when the number of index parameters is fixed. In many high-dimensional model selection problems, the number of parameters is increasing along with the sample size. In the first part of this work, we consider weakly dependent data and propose a class of variable selection procedures for single-index prediction models. We apply polynomial spline basis function expansion and smoothly clipped absolute deviation penalty to perform estimation and variable selection in the framework of a diverging number of index parameters. Under stationary and strong mixing conditions, the proposed variable selection method is shown to have the “oracle” property when the number of index parameters tends to infinity as the sample size increases. A fast and efficient iterative algorithm is developed to simultaneously estimate parameters and select significant variables. The finite sample behavior of the proposed method is evaluated with simulation studies and illustrated by some river flow data from Iceland. Most recently, among numerous modern problems in multiple scientific fields, a noteworthy characteristic feature is that the dimension of the explanatory variable, p, is large, and potentially much larger than the sample size, n. For those problems of large scale or dimensionality, variable selection again plays an important role in the modeling process. Under the sparsity assumption, a variable screening procedure was proposed by [16] to reduce the ultra-high dimensionality to a moderate level. However, for practical data analysis, without any prior knowledge, both the true model and the marginal regression can be highly non-linear. To address the above issues in the second part of this work, we investigate ultra-high dimensional penalized single-index models. We further extend the sure independence screening method into a nonparametric independence screening procedure. In addition, a data-driven thresholding determination procedure is proposed to enhance the finite sample performance. New theoretical results are also derived for oracle parameters. Both the numerical results and the real data application demonstrate that the proposed procedure works very well, even for moderate sample size and large dimensionality.
Spectral Properties of Fractional Quantum Hall Hamiltonians

OF THE DISSERTATION Spectral Properties of Fractional Quantum Hall Hamiltonians by Amila Weerasinghe Doctor of Philosophy in Physics Washington University in St. Louis, 2016 Professor Alexander Seidel, Chair The fractional quantum Hall (FQH) effect plays a prominent role in the study of topological phases of matter and of strongly correlated electron systems in general. FQH systems have been demonstrated to show many interesting novel properties such as fractional charges, and are believed to harbor even more intriguing phenomena such as fractional statistics. However, there remain many interesting questions to be addressed in this regime. The work reported in this thesis aims to push the envelope of our understanding of the low-energy properties of FQH states using microscopic principles. In the first part of the thesis, we present a systematic perturbative approach to study excitations in the thin cylinder/torus limit of the quantum Hall states. The approach is applied to the Haldane-Rezayi and Gaffnian quantum Hall states, which are both expected to have gapless excitations in the usual two-dimensional thermodynamic limit. For the Haldaneviii Rezayi state, we confirm that gapless excitations are present also in the “one-dimensional” thermodynamic limit of an infinite thin cylinder, in agreement with earlier considerations based on the wave functions alone. In contrast, we identify the lowest excitations of the Gaffnian state in the thin cylinder limit, and conclude that they are gapped, using a combination of perturbative and numerical means. We discuss possible scenarios for the cross-over between the two-dimensional and the one-dimensional thermodynamic limit in this case. In the second part of the thesis, we study the low energy spectral properties of positive center-of-mass conserving two-body Hamiltonians as they arise in models of FQH states. Starting from the observation that positive many-body Hamiltonians must have ground state energies that increase monotonously in particle number, we explore what general additional constraints can be obtained for two-body interactions with “center-of-mass conservation” symmetry, both in the presence and absence of particle-hole symmetry. We find general bounds that constrain the evolution of the ground state energy with particle number, and in particular constrain the chemical potential at T = 0. Special attention is given to Hamiltonians with zero modes, in which case similar bounds on the first excited state are also obtained, using a duality property. In this case, in particular an upper bound on the charge gap is also obtained. We further comment on center-of-mass and relative-decomposition in disk geometry within the framework of second quantization.
Possible substellar companions in low-mass eclipsing binaries: GU Bootis and YY Geminorum

We present the next results of our long-term observational project to analyze the variations in the orbital periods of low-mass eclipsing binaries. About 70 new precise mid-eclipse times recorded with a CCD were obtained for two eclipsing binaries with short orbital periods: GU Boo (P = 0.​d49) and YY Gem (0.​d81). Observed-minus-calculated diagrams of the stars were analyzed using all reliable timings, and new parameters of the light-time effect were obtained. We derived for the first time or improved the short orbital periods of possible third bodies of 11 and 54 years for these low-mass binaries, respectively. We calculated that the minimum masses of the third components are close to 50 MJup, which corresponds to the mass of brown dwarfs. The multiplicity of these systems also plays an important role in the precise determination of their physical parameters.
Detecting Fraudulent Financial Reporting with Financial Ratios: Case Study on Indonesia Stock Exchange

This study aimed to examine the significant differences in the financial ratios of FFR and non-FFR companies listed on the Indonesia Stock Exchange (IDX) in 2018-2019. It used the difference test of two population means and the Mann-Whitney U test to determine the financial ratios useful in distinguishing the companies. Furthermore, multiple logistic regression was employed to determine significant financial ratios as predictors against Fraudulent Financial Reporting (FFR). The M-Score formula was applied to classify the sample into 19 non-FFR and 59 FFR public companies. The results showed that seven financial ratios effectively differentiate FFR and non-FFR companies. Moreover, one significant financial ratio predicts FFR in public companies listed on the Indonesia Stock Exchange.
Mercury removal performance and mechanism of biochar co-modified with HNO3 and NH4Br under oxy-combustion atmosphere

ABSTRACT In order to meet the demand for mercury removal in the oxy-combustion atmosphere, a new mercury adsorbent was prepared by using rice husk char as raw material and co-modification of acid and halogen. The experimental results indicate that the specific surface area of the combined modified char is smaller than those modified by HNO3 and NH4Br alone, but it has better mercury removal performance. X-ray photoelectron spectroscopy (XPS) analysis shows that the co-modification can effectively promote the formation of C-O* and C-Br. The high activity of Br will induce the Hg0 adsorption, while C-O* will convert the easily decomposed HgBr2 into more stable HgO, which may be the reason why the combined modified char maintains high mercury removal efficiency. When the reaction temperature reaches 150°C, the mercury removal efficiency of RHC (Br+N) is almost 100%. Both above and below the optimum reaction temperature will affect the activity of chemical functional groups and inhibit mercury removal. According to the density functional theory (DFT) results, the addition of O and Br atoms can stably combine with the carbonaceous surface to form covalent compounds (C=O, C-Br), both of which can induce the charge transfer of surrounding C atoms, which makes the C atoms have stronger electronegativity and easier to chemically adsorb Hg0.
Homing Guidance Law Design against Maneuvering Targets Based on DDPG

A novel homing guidance law against maneuvering targets based on the deep deterministic policy gradient (DDPG) is proposed. The proposed guidance law directly maps the engagement state information to the acceleration of the interceptor, which is an end-to-end guidance policy. Firstly, the kinematic model of the interception process is described as a Markov decision process (MDP) that is applied to the deep reinforcement learning (DRL) algorithm. Then, an environment of training, state, action, and network structure is reasonably designed. Only the measurements of line-of-sight (LOS) angles and LOS rotational rates are used as state inputs, which can greatly simplify the problem of state estimation. Then, considering the LOS rotational rate and zero-effort-miss (ZEM), the Gaussian reward and terminal reward are designed to build a complete training and testing simulation environment. DDPG is used to deal with the RL problem to obtain a guidance law. Finally, the proposed RL guidance law’s performance has been validated using numerical simulation examples. The proposed RL guidance law demonstrated improved performance compared to the classical true proportional navigation (TPN) method and the RL guidance policy using deep-Q-network (DQN).
Statistics on Nonmigrating Diurnal Tides Generated by Tide-Planetary Wave Interaction and Their Relationship to Sudden Stratospheric Warming

The nonmigrating diurnal tide, DW2, is known to have a source from the stationary planetary wave with wavenumber 1 (SPW1) and the migrating diurnal tide (DW1) interaction. Recent research has shown that DW2 time evolution in the equatorial mesopause tracks very well with SPW1 in the polar stratosphere for the winter of 2009–2010, which contains a sudden stratospheric warming (SSW) vortex split event. This paper extends previous research and investigates the relationship between these two waves for 31 winters from 1979 to 2010 with the extended Canadian Middle Atmosphere Model (eCMAM) through correlation and composite analysis. Significant correlations are present between the two waves in 20 out of 31 winters (65%). We separate the 31 winters into four categories: SSW-displacement, SSW-split, minor-SSW, and no-SSW. Our results show that there is no significant difference among the four categories in terms of correlations between the two waves. Although SPW1 is usually stronger during a SSW-D winter, this does not warrant a stronger interaction with DW2.
The effects of a single or multi-step drop-set training compared to traditional resistance training on muscle performance and body composition

The purpose was to examine two drop-set (DS) protocols (single step vs. multi-step) compared to traditional resistance training (TRT) over 8 weeks on changes in muscular strength, endurance and body composition. Twenty-seven trained males were randomized to one of three groups: traditional resistance training (TRT: n = 9), the single step drop set group (DS-S: n = 10) and the multi-step drop set group (DS-M: n = 8). Before and after training, body composition (percent body fat and skeletal muscle mass), and muscular strength and endurance (bench and leg press) were determined. Results: There was a significant interaction for leg press 1-RM ( p < .001) and absolute change for leg-press 1-RM was significantly greater for both drop set protocols compared to TRT ( p < .001). There were significant interactions for both leg press and bench press endurance ( p < .001), with post hoc analyses revealing that only DS-M was superior to TRT ( p < .001). There was a significant main effect of time for % body fat ( p = .020), SMM ( p < .001), however there were no differences between groups. Conclusions: Overall, single-step and multi-step drop-set training to failure appear to be effective strategies to enhance lower body strength, while only the multi-step drop set training
Compact dual‐frequency patch antenna with large beamwidth diversity at flexible frequency ratio

A compact, single‐layer, dual‐frequency patch antenna with large beamwidth diversity, that is, broad beamwidth in the lower frequency and high‐gain radiation in the higher frequency is presented and analyzed in this paper. The antenna is in general composed of a square driven patch and two T‐shaped top‐loaded monopoles that are loaded beside the two radiating edges of the driven patch. Herein, the patch antenna to be operated in the fundamental TM01 mode intrinsically provides a pair of in‐phase magnetic currents and meanwhile, the top‐loaded monopoles produce a pair of out‐of‐phase vertical electric currents. In analysis, consistent broad beamwidth and high‐gain radiation pattern are, respectively, well maintained at the lower and higher frequencies, even with a frequency ratio as small as 1.02. Moreover, the antenna preserves simple geometry and high efficiency of a typical patch antenna. For verification, a prototype is in final fabricated and measured, which has experimentally confirmed its simulated radiation results.
Integrated Reporting and IFRS 3: an empirical study to Cost of Equity through Firm Risk and Investor Protection

This study examines the relation of cost of equity associated with the disclosure quality of IFRS 3 and the Integrated Reporting (IR) compliance. Employing an IR sample composed of 498 non-financial firms that use IR either mandatorily or voluntarily from 2011 to 2019, we investigate the impact of IR and IFRS 3 disclosure quality on the cost of equity. Based on Breuer et al. (2018) and Chava (2014) we suggest two distinct channels through which IR and IFRS 3 can influence the cost of equity: firm risk and investor base. In companies with strong legal, cultural, and political factors, our results show that the cost of equity falls when a firm invests in IR and at the same time provides high levels of IFRS 3 information. Moreover, we find that higher IFRS 3 disclosure score lowers firms’ risk in companies with high IR compliance. We interpret the negative relation at higher levels of disclosure as evidence that investors consider firms with low levels of IR informativeness to be riskier. Finally, we find that the negative impact of IFRS 3 disclosure quality and of IR compliance to cost of equity is more intense when firms’ risk is low. JEL Classification: C 33; G17; G32; L2; M14. Keywords: integrated reporting, IFRS 3, accounting disclosure quality, cost of equity, firm risk and investor protection
Bottom changes in coastal areas with complex shorelines

ABSTRACT A model for the sea-bottom change simulations in coastal areas with complex shorelines is proposed. In deep and intermediate water depths, the hydrodynamic quantities are calculated by numerically integrating the contravariant Boussinesq equations, devoid of Christoffel symbols. In the surf zone, the propagation of the breaking waves is simulated by the nonlinear shallow water equations. The momentum equation is solved inside the turbulent boundary layer in order to calculate intra-wave hydrodynamic quantities. An integral formulation for the contravariant suspended sediment advection-diffusion equation is proposed and used for the sea-bottom dynamic simulations. The proposed model is applied to the real case study of Pescara harbor (in Italy).
Sexual dimorphism in the badlands cricket (Orthoptera, Gryllinae, Gryllus personatus)

Sexual dimorphism (SD) is a common phenomenon in sexual species and can manifest in a variety of ways. Sexual size dimorphism (SSD) is commonly investigated, but it can be confounded with sexual shape dimorphism (SShD) if multivariate measures of size are not used. Univariate studies may also overestimate the prevalence or direction of SSD when the sexes are strikingly different in shape, which may be an issue in taxa such as Orthoptera and other terrestrial arthropods where maximum body size is strongly constrained. Here we tested for the occurrence of both SSD and SShD in the badlands cricket Gryllus personatus (Orthoptera, Gryllinae). We measured four body size dimensions—maxillae span, head width, pronotum length, and mean hind femur length—and used multivariate methods to test whether male and female adult badlands crickets were sexually dimorphic in size and/or shape. All the univariate dimensions were sexually dimorphic, with males having wider heads and maxillae than females and females having longer pronota and hind femora than males, which indicates SShD. However, multivariate methods failed to detect SSD, instead confirming that the sexes primarily differ in body shape. We show how a simple ratio of head width to pronotum length captures SShD in badlands crickets and apply it to iNaturalist, a citizen science platform, to broaden our findings. We propose that orthopterists studying SD minimally measure head width, pronotum length, and hind femur length as a standard that will allow a more repeatable and generalizable assessment of the prevalence and direction of both SSD and SShD.
Valorization of red ginger hydrodistillation wastes as foot sanitizers

Red ginger is known as one of the medicinnal and aromatic plants that have high value in the form of essential oils. The distillation of red ginger essential oils required large amounts of water, and then most of the water was disposed of as wastewater. This wastewater is known as hydrosol, which still contains a small amount of essential oils and secondary metabolites such as zingiberene and geraniol. These compounds were considered to have the potential to be utilized in cosmetic products such as foot sanitizers. The aim of this study was to evaluate a foot sanitizer product based on red ginger hydrosol that combined with coffee extracts based on its antibacterial activity against Staphylococcus aureus and the physical characteristics of the product. Foot sanitizer was produced in three formulations with different concentration (in percentage) of red ginger hydrosols and coffee extracts consist of F1 (45:25), F2 (35:35), and F3 (25:45). The results showed the F3 formulation provided the largest antibacterial inhibition (2.89±0.60 mm) compared to other formulations. The F3 formulation has a physical characteristics such as coffee scent aroma, a dark brown color, a pH of 5.5, a density of 960.73 kg/m3 and has a weak antibacterial activity. Based on the comparison results with previous studies, the utilization of coffee extracts in red ginger hydrosols-based foot sanitizer needs to be substitued with other natural extracts, especially having a strong antibacterial activity. It should be carried out to increase the potential value of valorizing red ginger hydrosols as foot sanitizer.
Scaling properties towards vortex reconnection under Biot–Savart evolution

Reconnection of a vortex filament under the Biot–Savart law is investigated numerically using a vortex ring twisted in the form of a figure-of-eight. For the numerical method, the vortex ring is divided into piecewise linear segments, and the Biot-Savart integral is approximated by a summation over the segments with a cut-off method to deal with the singular terms. It is demonstrated that the centre part of the skewed vortex ‘chopsticks’, where the interaction is maximal, tends to approach and accelerate to form a singularity while making a ‘tent-like’ structure as shown by de Waele and Aarts (1994 Phys. Rev. Lett. 72 pp 482–5). The minimum separation of the chopsticks, the maximum velocity and the maximum axial strain rate show clear scaling exponents near the singularity consistent with Leray scaling for self-similar solutions of the Navier–Stokes equations.
A synthetic view of the magnetospheric-ionospheric current system associated with substorms

Electric currents play an important role in the energy coupling between the magnetosphere and ionosphere. This paper examines in detail the distribution and dynamics of ionospheric electric currents during an isolated substorm. In particular, the relative contributions of ionospheric Pedersen and Hall currents to field-aligned currents are evaluated in hoping to shed some new light on the ionospheric closure of the substorm current wedge. It is found that the substorm-related westward electrojet is dominated by Hall current, which is 2∼3 times the Pedersen current in magnitude. Under winter-time substorm conditions, a significant portion (up to more than 1 MA) of field-aligned currents is closed in the ionosphere through Hall current. Although the contribution of Hall current to field-aligned currents is about 30∼50% compared to the contribution from Pedersen current, it is Hall current, not Pedersen current, that appears to be the main contributor to the substorm current wedge.
Epidemiological Profile and Associated Allergic Conditions of Atopic Dermatitis: Data from a Referral Service in Southeastern Brazil

Background: Atopic dermatitis is a chronic, inflammatory, and pruritic dermatosis of high prevalence, especially in childhood. a relevant public health issue. Atopic dermatitis is associated with several factors, including genetic, psychological, infectious, food, and environmental, and may be associated with other manifestations of atopy, such as asthma and rhinitis. Objective: To determine the epidemiological profile and the prevalence of personal and family history of allergy in children with atopic dermatitis at a referral service, comparing it to existing literature. Methods: We conducted a cross-sectional and descriptive hospital-based study involving children of both genders under 18 years with clinical diagnosis of atopic dermatitis (Hanifin and Rajka criteria) seen at the Pediatric Dermatology Outpatient Clinic of Hospital Municipal Universitário de Taubaté (HMUT), SP-Brazil, from October 2018 to April 2019. Epidemiological data and data related to personal and family history of allergies were collected from the medical records. Microsoft Excel 2019 was used for compilation and data analysis. Results: Of the 440 consultations in that period, 35 (7.9%) were for atopic dermatitis, of which 23 of them were females (65.7%) and 15 were phototype IV (42.9%); their mean age was 7.7 (standard deviation = 4.3), and the duration of disease ranged from 2 months to 14 years (mean 5.3 years; standard deviation = 4.3). Among the 35 patients, 31 (88.6%) manifested the condition by the fifth year of life. Personal history of allergies was observed in 27 individuals (77.1%), with a predominance of allergic rhinitis and in older age groups. Conclusion: This study, as a pioneer in the region, contributes to the epidemiological profile of patients with atopic dermatitis from the Pediatric Dermatology Outpatient Clinic of HMUT, revealing an early onset and a higher prevalence in females and individuals with higher phototypes. In addition, this study also demonstrated the prevalence of personal and family history of allergies in these patients, consistent with literature.