Miracle-dz/UniFAR-FTUs huggingface dataset:
Bidirectional Domain Mixup for Domain Adaptive Semantic Segmentation

Mixup provides interpolated training samples and allows the model to obtain smoother decision boundaries for better generalization. The idea can be naturally applied to the domain adaptation task, where we can mix the source and target samples to obtain domain-mixed samples for better adaptation. However, the extension of the idea from classification to segmentation (i.e., structured output) is nontrivial. This paper systematically studies the impact of mixup under the domain adaptive semantic segmentation task and presents a simple yet effective mixup strategy called Bidirectional Domain Mixup (BDM). In specific, we achieve domain mixup in two-step: cut and paste. Given the warm-up model trained from any adaptation techniques, we forward the source and target samples and perform a simple threshold-based cut out of the unconfident regions (cut). After then, we fill-in the dropped regions with the other domain region patches (paste). In doing so, we jointly consider class distribution, spatial structure, and pseudo label confidence. Based on our analysis, we found that BDM leaves domain transferable regions by cutting, balances the dataset-level class distribution while preserving natural scene context by pasting. We coupled our proposal with various state-of-the-art adaptation models and observe significant improvement consistently. We also provide extensive ablation experiments to empirically verify our main components of the framework. Visit our project page with the code at https://sites.google. com/view/bidirectional-domain-mixup
Delayed and Indirect Impacts of Link Recommendations

The impacts of link recommendations on social networks are challenging to evaluate, due to feedback loops between algorithmic recommendations and underlying network dynamics. Observational studies have limitations in answering causal questions; naive A/B experiments often result in biased evaluations due to unaccounted network interference and finally, existing simulations primarily employ static network models that do not take into account dynamics. Departing from existing approaches, we employ simulations to study dynamic impacts of link recommendations. Specifically, we propose an extension to the Jackson-Rogers network evolution model and investigate how link recommendations affect network evolution over time. Our experiments demonstrate that link recommendations can have surprising delayed and indirect effects on the structural properties of networks. Effects of recommendations vary in the short-term and long-term, such as the immediate reduction in degree inequality but eventual increase in degree inequality through friend-of-friend recommendations. Furthermore, even after recommendations are discontinued, their impacts can persist in the network, in part by altering natural network evolution dynamics. These results provide valuable insights into the interplay between algorithmic interventions and natural network dynamics and highlight the limitations of current evaluation paradigms.
Three dimensional chaos game representation of protein sequences

A new three dimensional approach to the chaos game representation of protein sequences is explored in this thesis. The basics of DNA, the synthesis of proteins from DNA, protein structure and functionality and sequence alignment techniques are presented. The mathematical background needed for understanding the chaos game representation and fractal analysis are briefly discussed. An account of the existing literature on the chaos game representation of DNA sequences and a detailed account of the chaos game representation of protein sequences in two dimensions with its advantages and limitations are presented. We explore a new three dimensional approach to the chaos game representation of protein sequences (3D-CGR) and study its ability a) to determine protein sequence similarity and differences, b) to study the effect of dinucleotide biases at amino acid level on the 3D-CGR derived protein homology, and c) to identify sequence similarity based on shuffled motifs that could be used for studying protein evolution due to exon shuffling.
Exploiting Semantic Attributes for Transductive Zero-Shot Learning

Zero-shot learning (ZSL) aims to recognize unseen classes by generalizing the relation between visual features and semantic attributes learned from the seen classes. A recent paradigm called transductive zero-shot learning further leverages unlabeled unseen data during training and has obtained impressive results. These methods always synthesize unseen features from attributes through a generative adversarial network to mitigate the bias towards seen classes. However, they neglect the semantic information in the unlabeled unseen data and thus fail to generate high-fidelity attribute-consistent unseen features. To address this issue, we present a novel transductive ZSL method that produces semantic attributes of the unseen data and imposes them on the generative process. In particular, we first train an attribute decoder that learns the mapping from visual features to semantic attributes. Then, from the attribute decoder, we obtain pseudo-attributes of unlabeled data and integrate them into the generative model, which helps capture the detailed differences within unseen classes so as to synthesize more discriminative features. Experiments on five standard benchmarks show that our method yields state-of-the-art results for zero-shot learning.
Confirmatory Factor Analysis for Applied Research

Introduction. Factor Model and Exploratory Factor Analysis. Introduction to CFA. Specification and Interpretation of CFA Models. CFA Model Revision and Comparison. CFA of Multitrait-Multimethod Matrices. CFA with Equality Constraints, Multiple Groups, and Mean Structures. Other Types of CFA Models: Higher-Order Factor Analysis, Scale Reliability Evaluation, and Formative Indicators. Data Issues in CFA: Missing, Non-Normal, and Categorical Data. Statistical Power and Sample Size.
A Recipe for Watermarking Diffusion Models

Diffusion models (DMs) have demonstrated advantageous potential on generative tasks. Widespread interest exists in incorporating DMs into downstream applications, such as producing or editing photorealistic images. However, practical deployment and unprecedented power of DMs raise legal issues, including copyright protection and monitoring of generated content. In this regard, watermarking has been a proven solution for copyright protection and content monitoring, but it is underexplored in the DMs literature. Specifically, DMs generate samples from longer tracks and may have newly designed multimodal structures, necessitating the modification of conventional watermarking pipelines. To this end, we conduct comprehensive analyses and derive a recipe for efficiently watermarking state-of-the-art DMs (e.g., Stable Diffusion), via training from scratch or finetuning. Our recipe is straightforward but involves empirically ablated implementation details, providing a foundation for future research on watermarking DMs. The code is available at https://github.com/yunqing-me/WatermarkDM.
Phonon-Mediated ${\bf S}$-Wave Superconductivity in the Kagome Metal CsV$_3$Sb$_5$ under Pressure

The nature of the superconducting pairing state in the pristine phase of a compressed kagome metal CsV$_3$Sb$_5$ under pressure is studied by the Migdal-Eliashberg formalism and density-functional theory calculations. We find that the superconducting gap distribution driven by electron-phonon coupling is nodeless and anisotropic. It is revealed that the hybridized V 3$d$ and Sb 5$p$ orbitals are strongly coupled to the V-V bond-stretching and V-Sb bond-bending phonon modes, giving rise to a wide spread of superconducting gap depending on its associated Fermi-surface sheets and momentum. Specifically, the superconducting gaps associated with V 3$d_{xy,x^2-y^2,z^2}$ and 3$d_{xz,yz}$ orbitals are larger in their average magnitude and more widely spread compared to that associated with the Sb 5$p_z$ orbital. Our findings demonstrate that the superconductivity of compressed CsV$_3$Sb$_5$ can be explained by the anisotropic multiband pairing mechanism with conventional phonon-mediated $s$-wave symmetry, evidenced by recent experimental observations under pressure as well as at ambient pressure.
On the finite time blow-ups for solutions of nonlinear differential equations

We study systems of nonlinear ordinary differential equations where the dominant term, with respect to large spatial variables, causes blow-ups and is positively homogeneous of a degree $1+\alpha$ for some $\alpha>0$. We prove that the asymptotic behavior of a solution $y(t)$ near a finite blow-up time $T_*$ is $(T_*-t)^{-1/\alpha}\xi_*$ for some nonzero vector $\xi_*$. Specific error estimates for $|(T_*-t)^{1/\alpha}y(t)-\xi_*|$ are provided. In some typical cases, they can be a positive power of $(T_*-t)$ or $1/|\ln(T_*-t)|$. This depends on whether the decaying rate of the lower order term, relative to the size of the dominant term, is of a power or logarithmic form. Similar results are obtained for a class of nonlinear differential inequalities with finite time blow-up solutions. Our results cover larger classes of nonlinear equations, differential inequalities and error estimates than those in the previous work.
Estimating the density of a copula function

This paper deals with estimation of the density of a copula function as well as with that of the Radon-Nikodym derivative of a bivariate distribution function with respect to the product of its marginal distribution functions. Strong uniform consistency and asymptotic normality of kernel-type estimators are proved under various conditions on the bandwidth and on the smoothness of the kernel. As an application, the estimation of Neyman-Pearson curves in the testing of independence problem is discussed.
Valence fluctuations in thin films and the α and δ phases of Pu metal determined by 4f core-level photoemission calculations

The average number of 5f electrons making up the valence state in plutonium metal together with the electronic fluctuations on each metal site has been a recent subject of debate. For the phase of Pu, where compared to the phase increased localization more atomiclike character leads to decreased overlap and volume increase, an f count close to either 5 or 6 has been proposed depending on the type of electronic structure calculation. In order to resolve the controversy, we analyze the Pu 4f photoemission spectrum, which displays well screened and poorly screened peaks that can be used as a measure for the degree of localization. A simple analytical two-level model already shows on general grounds that the f count for Pu must be between 5 and 5.5. Furthermore, we present detailed Anderson impurity model calculations including the full multiplet structure for Pu 4f photoemission, which are compared to previous experimental results obtained from 1 to 9 monolayers thin films of Pu on Mg and from Pu metal in the and phases. The trend in the satellite to main peak intensity ratio as a function of the Pu layer thickness gives a clear indication that Pu metal has an 5f5 like ground state. For the Pu allotropes and thicker films an f count of 5.22 is obtained with a Coulomb interaction U=4 eV. The 5f fluctuations in Pu metal are very prominent and strongly material dependent. The calculations give a ground state with 9.6% f4, 58.8% f5, and 31.6% f6 for the phase and 5.7% f4, 66.4% f5, and 27.8% f6 for the phase while for the thin films the amount of f5 and the localization strongly increase with reduced thickness. The obtained findings are in agreement with recent electronic structure calculations for Pu using local-density approximation with dynamical mean-field theory and with the branching-ratio analysis of the Pu N4,5 edge in electron-energy-loss spectroscopy.
Enhancing the Role of Context in Region-Word Alignment for Object Detection

Vision-language pretraining to learn a fine-grained, region-word alignment between image-caption pairs has propelled progress in open-vocabulary object detection. We observe that region-word alignment methods are typically used in detection with respect to only object nouns, and the impact of other rich context in captions, such as attributes, is unclear. In this study, we explore how language context affects downstream object detection and propose to enhance the role of context. In particular, we show how to strategically contextualize the grounding pretraining objective for improved alignment. We further hone in on attributes as especially useful object context and propose a novel adjective and noun-based negative sampling strategy for increasing their focus in contrastive learning. Overall, our methods enhance object detection when compared to the state-of-the-art in region-word pretraining. We also highlight the fine-grained utility of an attribute-sensitive model through text-region retrieval and phrase grounding analysis.
Observational data analysis of Spitzer Infrared Spectrograph low-resolution spectra of ultraluminous infrared galaxies with Seyfert spectral types from the 1-Jy sample

In this paper, we present the Spitzer Infrared Spectrograph (IRS) low-resolution spectra of ultraluminous infrared galaxies with Seyfert spectral types from the 1-Jy sample. Among these sources, nine type 1 Seyfert galaxies and 17 type 2 Seyfert galaxies have Spitzer IRS low-resolution observations. For Seyfert 1 sources, we find that all sources have [Ne V] and/or [S IV] features, indicating an active galactic nucleus (AGN) nature, while many sources show polycyclic aromatic hydrocarbon (PAH) features, indicative of starburst activity. It is also found that most Seyfert 2 sources have mid-infrared spectra similar to that for Seyfert 1 sources, also indicating an AGN nature, and thus these could be classified as Seyfert 1-like sources. However, only a few sources have a normal Seyfert 2 nature and can be considered to be 'pure' Seyfert 2 sources. In addition, it is found that more prominent PAH features are found for Seyfert 2 sources, indicating strong star formation activity.
Banach algebras associated to twisted \'etale groupoids: inverse semigroup disintegration and representations on $L^p$-spaces

We introduce Banach algebras associated to a twisted \'etale groupoid $(\mathcal{G},\mathcal{L})$ and to twisted inverse semigroup actions. This provides a unifying framework for numerous recent papers on $L^p$-operator algebras and the theory of groupoid $C^*$-algebras. We prove a disintegration theorem that allows us to study Banach algebras associated to $(\mathcal{G},\mathcal{L})$ as universal Banach algebras generated by $C_0(X)$ and a twisted inverse semigroup $S$ of partial isometries subject to some relations. Our theory works best when the groupoid is ample or when the target of a representation is a dual Banach algebra $B$, so for instance $B=B(E)$ where $E$ is a reflexive Banach space. In particular, it implies that in the constructions of $L^p$-analogues of Cuntz or graph algebras, by Phillips and Corti\~{n}as--Rodr\'{\i}guez, the use of \emph{spatial partial isometries} is not an assumption, in fact it is forced by the relations. We establish fundamental norm estimates and hierarchy for full and reduced $L^p$-operator algebras for $(\mathcal{G},\mathcal{L})$ and $p \in [1,\infty]$, whose special cases have been studied recently by Gardella--Lupini, Choi--Gardella--Thiel and Hetland--Ortega. We also introduce tight inverse semigroup Banach algebras that cover ample groupoid Banach algebras, and we discuss Banach algebras associated to twisted partial group actions, twisted Renault--Deaconu groupoids and directed graphs. Our Banach Cuntz algebras are related to the construction of Daws--Horv\'{a}th. We aim for a high degree of generality throughout: our results cover non-Hausdorff \'{e}tale groupoids and both real and complex algebras. Some of our results seem to be absent from the literature even for $C^*$-algebras.
Asymmetric Mathieu equations

An inverted pendulum with asymmetric elastic restraints (e.g. a one-sided spring), when subjected to harmonic vertical base excitation, on linearizing trigonometric terms, is governed by an asymmetric Mathieu equation. This system is parametrically forced and strongly nonlinear (linearization for small motions is not possible). However, solutions are scaleable: if x(t) is a solution, then so is αx(t) for any real α>0. We numerically study the stability regions in the parameter plane of this system for a fixed degree of asymmetry in the elastic restraints. A Lyapunov-like exponent is defined and numerically evaluated to find these regions of stable and unstable behaviour. These numerics indicate that there are infinitely many possibilities of instabilities in this system that are missing in the usual or symmetric Mathieu equation. We find numerically that there are periodic solutions at the boundaries of stable regions in the parameter plane, analogous to the symmetric Mathieu equation. We compute and plot several of these solution branches, which provide a relatively simpler means of computing the stability transition curves of this system. We prove theoretically that such periodic solutions must exist on all stability boundaries. Our theoretical results apply to the asymmetric Hill's equation, of which the pendulum system is a special case. We demonstrate this with numerical studies of a more general asymmetric Mathieu equation.
Conflict Optimization for Binary CSP Applied to Minimum Partition into Plane Subgraphs and Graph Coloring

CG:SHOP is an annual geometric optimization challenge and the 2022 edition proposed the problem of coloring a certain geometric graph defined by line segments. Surprisingly, the top three teams used the same technique, called conflict optimization. This technique has been introduced in the 2021 edition of the challenge, to solve a coordinated motion planning problem. In this article, we present the technique in the more general framework of binary constraint satisfaction problems (binary CSP). Then, the top three teams describe their different implementations of the same underlying strategy. We evaluate the performance of those implementations to vertex color not only geometric graphs, but also other types of graphs.
Atmospheres as windows into sub-Neptune interiors: coupled chemistry and structure of hydrogen–silane–water envelopes

Sub-Neptune exoplanets are commonly hypothesized to consist of a silicate-rich magma ocean topped by a hydrogen-rich atmosphere. Previous work studying the outgassing of silicate material has demonstrated that such atmosphere–interior interactions can affect the atmosphere’s overall structure and extent. However, these models only considered SiO in an atmosphere of hydrogen gas, without considering chemical reactions between them. Here, we couple calculations of the chemical equilibrium between H, Si, and O species with an atmospheric structure model. We find that substantial amounts of silane, SiH4, and water, H2O, are produced by the interaction between the silicate-rich interior and hydrogen-rich atmosphere. These species extend high into the atmosphere, though their abundance is greatest at the hottest, deepest regions. For example, for a 4 M⊕ planet with an equilibrium temperature of 1000 K, a base temperature of 5000 K, and a 0.1 M⊕ hydrogen envelope, silicon species and water can comprise 30 per cent of the atmosphere by number at the bottom of the atmosphere. Due to this abundance enhancement, we find that convection is inhibited at temperatures ≳2500 K. This temperature is lower, implying that the resultant non-convective region is thicker, than was found in previous models that did not account for atmospheric chemistry. Our findings show that significant endogenous water is produced by magma–hydrogen interactions alone, without the need to accrete ice-rich material. We discuss the observability of the signatures of atmosphere–interior interaction and directions for future work, including condensate lofting and more complex chemical networks.
On closed surfaces with nonnegative curvature in the spectral sense

We study closed orientable surfaces satisfying the spectral condition $\lambda_1(-\Delta+\beta K)\geq\lambda\geq0$, where $\beta$ is a positive constant and $K$ is the Gauss curvature. This condition naturally arises for stable minimal surfaces in 3-manifolds with positive scalar curvature. We show isoperimetric inequalities, area growth theorems and diameter bounds for such surfaces. The validity of these inequalities are subject to certain bounds for $\beta$. Associated to a positive super-solution $\Delta\varphi\leq\beta K\varphi$, the conformal metric $\varphi^{2/\beta}g$ has pointwise nonnegative curvature. Utilizing the geometry of the new metric, we prove H\"older precompactness and almost rigidity results concerning the main spectral condition.
Numerical Analyses of Exhaust and Refill Processes of a Laser Pulse Jet

The exhaust-refill processes in a laser pulse jet with a conical nozzle are simulated using computational fluid dynamics to clarify the analytically unpredictable decreasing tendency of a momentum-coupling coefficient with an increasing nozzle apex angle. Because the exhaust-refill processes result from an adiabatically expanding blast wave after laser heating, a valid explosion source based on a measurement is used to drive the blast wave instead of a laser-absorption process. Results of computations show that processes that occur until the shock front of a blast wave reaches the nozzle exit are similar, irrespective of the nozzle apex angle. However, after the blast wave leaves the nozzle edge, the behavior of the rarefaction wave induced behind the shock wave depends greatly on the nozzle apex angle. In the case of small apex angles, successive refilling mechanisms with a vortex are activated by the prominently evolved rarefaction wave. In contrast, in the case of large apex angles, this mechanism disappears, due to the moderate evolution of the rarefaction wave. This difference creates a tendency of the momentum-coupling coefficient to decrease with the apex angle.
The countability index of the endomorphism semigroup of a vector space

The countability index C(S) of a semigroup S is the least positive integer n, if such an integer exists, with the property that every countable subset of S is contained in a subsemigroup with n generators. If no such integer exists. C(S) is defined to be infinite. Let V be a vector space over a field F and denote by End V the endomorphism semigroup of V. In the two main results, it is determined precisely when C(End V)=2 and when C(End V)=x SpecificallyC(End V)=2 if and only if V is infinite dimensional or dim V=1 and F is finite and C(End V)=x if and only if F is infinite and dim V is an integer N1.
Explaining the hard excesses in active galactic nuclei

A common model invoked to describe the X-ray spectra of active galaxies includes a relativistically blurred reflection component, which in some cases can be the dominant contributor to the received flux. Alternative interpretations are often based around complex absorption, and to date it has proven difficult to determine between these two viable models. Recent works on Suzaku observations of the active nuclei in NGC 1365, 1H0419―577 and PDS 456 have found the presence of strong X-ray emission at high (∼10―50 keV) energies, referred to as 'hard excesses', and it has been claimed that this emission cannot be explained with simple disc reflection models. Here we investigate the high-energy emission in these sources by constructing disc reflection models and show that they can successfully reproduce the observed spectra. In addition, we find the behaviour of NGC 1365, 1 H 0419-577 in these observations to be broadly consistent with previous work on disc reflection interpretations.