Miracle-dz/UniFAR-FTUs huggingface dataset:
The Spitzer c2d Survey of Large, Nearby, Interstellar Clouds. IX. The Serpens YSO Population as Observed with IRAC and MIPS

We discuss the combined IRAC/MIPS c2d Spitzer Legacy observations of the Serpens star-forming region. We describe criteria for isolating bona fide YSOs from the extensive background of extragalactic objects. We then discuss the properties of the resulting high-confidence set of 235 YSOs. An additional 51 lower confidence YSOs outside this area are identified from the MIPS data and 2MASS photometry. We present color-color diagrams to compare our observed source properties with those of theoretical models for star/disk/envelope systems and our own modeling of the objects that are well represented by a stellar photosphere plus circumstellar disk. These objects exhibit a wide range of disk properties, from many with actively accreting disks to some with both passive disks and even possibly debris disks. The YSO luminosity function extends down to at least a few times 10-3 L☉ or lower. The lower limit may be set more by our inability to distinguish YSOs from extragalactic sources than by the lack of YSOs at very low luminosities. We find no evidence for variability in the shorter IRAC bands between the two epochs of our data set, Δt ~ 6 hr. A spatial clustering analysis shows that the nominally less evolved YSOs are more highly clustered than the later stages. The background extragalactic population can be fitted by the same two-point correlation function as seen in other extragalactic studies. We present a table of matches between several previous infrared and X-ray studies of the Serpens YSO population and our Spitzer data set. The clusters in Serpens have a very high surface density of YSOs, primarily with SEDs suggesting extreme youth. The total number of YSOs, mostly Class II, is greater outside the clusters.
Investigation of An Integrated Battery Charger for EVs based on A Dual-Motor Traction System

In this paper, to provide a convenient and low-cost charging solution for dual-motor EVs, a dual-motor traction system is employed to build an integrated on-board battery charger. In the proposed system, a five-phase flux-switching permanent-magnet (FSPM) motor and a three-phase FSPM motor are employed as the front and rear driving motor respectively in the driving mode. While in the charging mode, the five-phase FSPM motor and its inverter are applied to construct a boost-based ac/dc converter, which converts the grid power into dc, as well as the three-phase FSPM motor and its inverter are used as a buck converter to adjust the dc voltage to satisfy the battery charging requirement. The effectiveness of the proposed integrated charger is verified by simulation.
Splitting with Near-Circulant Linear Systems: Applications to Total Variation CT and PET

Many imaging problems, such as total variation reconstruction of X-ray computed tomography (CT) and positron-emission tomography (PET), are solved via a convex optimization problem with near-circulant, but not actually circulant, linear systems. The popular methods to solve these problems, alternating direction method of multipliers (ADMM) and primal-dual hybrid gradient (PDHG), do not directly utilize this structure. Consequently, ADMM requires a costly matrix inversion as a subroutine, and PDHG takes too many iterations to converge. In this paper, we present near-circulant splitting (NCS), a novel splitting method that leverages the near-circulant structure. We show that NCS can converge with an iteration count close to that of ADMM, while paying a computational cost per iteration close to that of PDHG. Through experiments on a CUDA GPU, we empirically validate the theory and demonstrate that NCS can effectively utilize the parallel computing capabilities of CUDA.
A note on Santaló inequality for the polarity transform and its reverse

We prove a Santal\'{o} and a reverse Santal\'{o} inequality for the polarity transform, which was recently re-discovered by Artstein-Avidan and Milman, in the class consisting of (even) log-concave functions attaining their maximal value 1 at the origin, also called geometric log-cancave functions. The bounds are sharp up to the optimal universal constants.
How a “Hit” is Born: The Emergence of Popularity from the Dynamics of Collective Choice

In recent times there has been a surge of interest in seeking out patterns in the aggregate behavior of socio-economic systems. One such domain is the emergence of statistical regularities in the evolution of collective choice from individual behavior. This is manifested in the sudden emergence of popularity or "success" of certain ideas or products, compared to their numerous, often very similar, competitors. In this paper, we present an empirical study of a wide range of popularity distributions, spanning from scientific paper citations to movie gross income. Our results show that in the majority of cases, the distribution follows a log-normal form, suggesting that multiplicative stochastic processes are the basis for emergence of popular entities. This suggests the existence of some general principles of complex organization leading to the emergence of popularity. We discuss the theoretical principles needed to explain this socio-economic phenomenon, and present a model for collective behavior that exhibits bimodality, which has been observed in certain empirical popularity distributions.
A note on the Liénard-Chipart criterion and roots of some families of polynomials

We present some inequalities that provide different sufficient conditions for an univariate monic polynomial to be Hurwitz unstable. These are motivated by difficult control problems where direct application of the Li\'enard-Chipart criterion is not feasible. Hurwitz stability of some polynomials of degree five is also discussed. These results may be interpreted as stability results for some interval polynomials.
Encapsulated formulation of the selective frequency damping method

We present an alternative “encapsulated” formulation of the selective frequency damping method for finding unstable equilibria of dynamical systems, which is particularly useful when analysing the stability of fluid flows. The formulation makes use of splitting methods, which means that it can be wrapped around an existing time-stepping code as a “black box. ” The method is first applied to a scalar problem in order to analyse its stability and highlight the roles of the control coefficient χ and the filter width Δ in the convergence (or not) towards the steady-state. Then the steady-state of the incompressible flow past a two-dimensional cylinder at Re = 100, obtained with a code which implements the spectral/hp element method, is presented.
Polycystic Ovarian Syndrome (PCOS): Does the Challenge End at Conception?

Polycystic ovary syndrome (PCOS) is a prevalent condition that not only has the potential to impede conception but also represents the most common endocrine dysfunction in fertile women. It is considered a heterogeneous and multifaceted disorder, with multiple reproductive and metabolic phenotypes which differently affect the early- and long-term syndrome’s risks. Undoubtedly, the impact of PCOS on infertility has attracted most of the attention of healthcare providers and investigators. However, there is growing evidence that even after conception is achieved, PCOS predisposes the parturient to several adverse pregnancy outcomes including a high risk of pregnancy-induced hypertension, spontaneous abortion, gestational diabetes, preeclampsia, and preterm birth, which increase the risks of stillbirth and neonatal death. Fetal growth abnormalities may also be more common, but the relationship is less well defined. This narrative review aims to summarize current knowledge regarding these conditions as they interplay with PCOS and concludes that although there appears to be an increase in these complications during the pregnancy of women with PCOS, there is a need for further research to clarify the possible confounding impact of obesity. Implications for clinical practice and future research are outlined.
Attracting random walks

This paper introduces the Attracting Random Walks model, which describes the dynamics of a system of particles on a graph with $n$ vertices. At each step, a single particle moves to an adjacent vertex (or stays at the current one) with probability proportional to the exponent of the number of other particles at a vertex. From an applied standpoint, the model captures the rich get richer phenomenon. We show that the Markov chain exhibits a phase transition in mixing time, as the parameter governing the attraction is varied. Namely, mixing time is $O(n\log n)$ when the temperature is sufficiently high and $\exp(\Omega(n))$ when temperature is sufficiently low. When $\mathcal{G}$ is the complete graph, the model is a projection of the Potts model, whose mixing properties and the critical temperature have been known previously. However, for any other graph our model is non-reversible and does not seem to admit a simple Gibbsian description of a stationary distribution. Notably, we demonstrate existence of the dynamic phase transition without decomposing the stationary distribution into phases.
Random simplicial complexes, duality and the critical dimension

In this paper, we discuss two general models of random simplicial complexes which we call the lower and the upper models. We show that these models are dual to each other with respect to combinatorial Alexander duality. The behavior of the Betti numbers in the lower model is characterized by the notion of critical dimension, which was introduced by Costa and Farber in [Large random simplicial complexes III: The critical dimension, J. Knot Theory Ramifications 26 (2017) 1740010]: random simplicial complexes in the lower model are homologically approximated by a wedge of spheres of dimension equal the critical dimension. In this paper, we study the Betti numbers in the upper model and introduce new notions of critical dimension and spread. We prove that (under certain conditions) an upper random simplicial complex is homologically approximated by a wedge of spheres of the critical dimension.
Analysis of Energy Storage Participation Policies in an Electricity Market Environment

As an essential technology to solve renewable energy absorption, energy storage plays a vital role in the new power system. However, the cost recovery of energy storage is complex, and government subsidies are still needed at this stage. To save government investment and improve the economic benefits of energy storage, the authorities need to choose an appropriate technology route so that the market can better allocate energy storage resources. The paper studies the current situation and policies of energy storage participation in the electricity market and provides essential experience for developing the regional electricity market in China. The main goal of energy storage is to maximize the portfolio’s profitability and find a balance between market revenues, overall storage costs, and reliable operations. The results of this paper suggest that the relevant authorities should clarify the main identity of energy storage in the electricity market and revise the mechanisms to help it participate in the ancillary services market, and should allow large storage plants and aggregated distributed storage to participate in each market segment, allowing them to trade flexibly in each market to exploit their flexibility and system value fully.
Uncertainty sources in flood projections over contrasting hydrometeorological regimes

ABSTRACT This study evaluates the uncertainty of four components of the hydroclimatic modelling chain on flood projections over 96 basins covering contrasting hydrometeorological regimes located in Canada and Mexico. Two ensembles of climate simulations are considered, a large ensemble of 22 global climate model simulations and a smaller ensemble of three high-resolution regional climate model simulations. The other components are two post-processing techniques, three lumped hydrological models and six probability distributions. These four sources are assessed through a method of variance decomposition applied to six flood indicators over a reference period and two future periods: 1976–2005, 2041–2070 and 2070–2099. Systematic differences are observed between basins with contrasting flood-generating processes. Snow-dominated basins consistently show larger variance contributions from hydrological models, while rain-dominated basins show climate simulations as their dominant source. These results underline the need to consider the variability of each component’s uncertainty contribution and its link to hydroclimatic conditions and dominant processes.
A Health Indicator Construction Method Based on Unsupervised Parallel Multiscale Neural Networks

The construction of health indicators (HI) is an essential parts of prognostics and health management (PHM). A good health indicator can accurately reflect the mechanical degradation process. Currently, most health indicator construction methods rely on abundant expert knowledge, but expert knowledge may be challenging to obtain. To solve this problem, this paper proposes a HI construction method based on unsupervised parallel multiscale convolutional long short-term memory neural network (PMCLSTM). Firstly, multiscale convolutional neural network (MSCNN) and multiscale long short-term memory neural network (MSLSTM) were used to extract multi-dimensional local and global features in parallel. Under the action of the LSTM neural network, the local jitter caused by CNN can be effectively reduced. Then, the linear regression (LR) model was used to fuse and reduce the acquired features to construct feature vectors. Finally, the relative similarity of the feature vector between the initial sample data and the current sample data is calculated, and the normalization method is used to construct the health indicator. The model is validated on the railway wagon wheel wear dataset and compared quantitatively with some advanced methods using two metrics, monotonicity and trendability. The experimental results show that the constructed HI is improved in both monotonicity and trendability, and the predicted remaining useful life of the wheel is in good agreement with the real remaining useful life, which can effectively identify the mechanical degradation process.
Diffraction-optimized surface structures for enhanced light harvesting in organic solar cells

Surface phase gratings for organic solar cells are designed, compared and optimized with respect to their ability to diffract incident light and thus increase its path length in the active layer and finally its absorption probability. The gratings are based on concentric rings, a Fermat's spiral or an Archimedean spiral. They exhibit circular symmetric diffraction patterns and therefore diffract light independent of its azimuthal angle. The grating pillars are arranged on these patterns according to a periodic sequence or the deterministic aperiodic Thue-Morse or Rudin-Shapiro sequences to further tailor the desired diffraction pattern. After additional parameter optimization, one of the most promising patterns, the Thue-Morse sequence on an Archimedean spiral, leads to a current density increase of 5%.
G Protein-Coupled Receptors Regulated by Membrane Potential

G protein-coupled receptors (GPCRs) are involved in a vast majority of signal transduction processes. Although they span the cell membrane, they have not been considered to be regulated by the membrane potential. Numerous studies over the last two decades have demonstrated that several GPCRs, including muscarinic, adrenergic, dopaminergic, and glutamatergic receptors, are voltage regulated. Following these observations, an effort was made to elucidate the molecular basis for this regulatory effect. In this review, we will describe the advances in understanding the voltage dependence of GPCRs, the suggested molecular mechanisms that underlie this phenomenon, and the possible physiological roles that it may play.
Decentralized DNN Task Partitioning and Offloading Control in MEC Systems With Energy Harvesting Devices

In this paper, we study a decentralized deep neural network (DNN) task partitioning and offloading control problem for a multi-access edge computing (MEC) system with multiple wireless devices (WDs) powered by renewable energy sources. Instead of generic computational tasks, we focus on the case when the WDs and the MEC systems are computing DNN inferencing tasks. For each WD, we build a virtual local-computing CPU workload queue and an energy queue to model the DNN computation dynamics and the battery energy dynamics, respectively. We first introduce a new Lyapunov function based on the DNN tasks' cumulative execution latency and the total energy consumptions of the entire MEC system. Using a Lyapunov optimization approach, the DNN task partitioning and offloading control at the WDs are formulated as a Lyapunov drift minimization problem. To facilitate a distributed implementation, we exploit the linear structure of the cumulative latency and the independency of each WD's local-computing CPU rate, and we decompose the centralized Lyapunov drift minimization problem into multiple distributed subproblems, each of which is associated with a single WD. Next, we develop a parametric online learning algorithm such that each sub-Lyapunov drift minimization problem is solved locally at its associated WD. The proposed solution is completely decentralized in the sense that the sequential offloading and DNN task segmentation control at each WD is determined by its local battery energy queue state information (EQSI), the channel state information (CSI), and the DNN inferencing task workload queue state information (TQSI). Numerical results reveal that the proposed online learning algorithm can achieve significant performance gain over various state-of-the-art baselines.
Assessing the Impact of Education on the Uptake of Health Insurance at the Cape Coast Technical University, Ghana

Historically, health financing in Ghana was cash and carry from the 1980s until the year 2005 when National Health Insurance Scheme (NHIS) started operation. Due to the barriers surrounding the ‘‘out-of-pocket’’ (OOP) regime on healthcare, Ghana adopted health insurance as an alternative for financing healthcare. The National Health Insurance Scheme was thus introduced in 2003 as a step towards achieving universal health coverage. This was aimed at bringing hope, better health and easing the financial burden on the entire population of Ghana especially the most vulnerable and poor. The study assesses the impact of education on the uptake of the National Health Insurance Policy among the staff of Cape Coast Technical University and its policy implication in achieving universal coverage. A descriptive research design and quantitative research approaches were adopted in this study. A survey of 200 staff of Cape Coast Technical University was conducted using a proportionate stratified sample technique to ensure a smooth representation of individuals. Questionnaires were used to collect data for this study. The results of the ordinary least square regression proved that level of education statistically influenced the uptake of health insurance. The study recommends that policymakers should continue to invest in the education of Ghanaians. Keywords: Heath, National Health Insurance, Uptake of Insurance, Education, and Cape Coast Technical University.
LOCALLY NORMAL SUBGROUPS OF TOTALLY DISCONNECTED GROUPS. PART II: COMPACTLY GENERATED SIMPLE GROUPS

We use the structure lattice, introduced in Part I, to undertake a systematic study of the class $\mathscr{S}$ consisting of compactly generated, topologically simple, totally disconnected locally compact groups that are nondiscrete. Given $G\in \mathscr{S}$ , we show that compact open subgroups of $G$ involve finitely many isomorphism types of composition factors, and do not have any soluble normal subgroup other than the trivial one. By results of Part I, this implies that the centralizer lattice and local decomposition lattice of $G$ are Boolean algebras. We show that the $G$ -action on the Stone space of those Boolean algebras is minimal, strongly proximal, and microsupported. Building upon those results, we obtain partial answers to the following key problems: Are all groups in $\mathscr{S}$ abstractly simple? Can a group in $\mathscr{S}$ be amenable? Can a group in $\mathscr{S}$ be such that the contraction groups of all of its elements are trivial?
Limitations and Solutions of LLC Topology in High Power High Step-up Applications on Aircraft

In modern aircraft, there is a huge demand for high power high step-up (HPHS) DC-DC conversion from 28V to 270V or even higher voltage, such as Start Power Unit (SPU) and backup power supply systems. Due to high efficiency, high power density, low EMI, and soft-switching capability, LLC resonant topology are receiving special attention. However, when it comes to HPHS applications, original LLC resonant topology will encounter some limitations, resulting poor parameter controllability, low power density and low efficiency. This paper first analyzed the fundamental causes of these limitations. Then, solutions are given in terms of circuit topology and system architecture, respectively. A 5kW 2SV/222V prototype was designed, fabricated and tested. The feasibility of proposed solutions is validated.
Approximating the Analytic Fourier Transform with the Discrete Fourier Transform

The Fourier transform is approximated over a finite domain using a Riemann sum. This Riemann sum is then expressed in terms of the discrete Fourier transform, which allows the sum to be computed with a fast Fourier transform algorithm more rapidly than via a direct matrix multiplication. Advantages and limitations of using this method to approximate the Fourier transform are discussed, and prototypical MATLAB codes implementing the method are presented.
The free splitting complex of a free group, II: Loxodromic outer automorphisms

We study the loxodromic elements for the action of O u t ( F n ) \mathsf {Out}(F_n) on the free splitting complex of the rank n n free group F n F_n . Each outer automorphism is either loxodromic or has bounded orbits without any periodic point, or has a periodic point; all three possibilities can occur. Two loxodromic elements are either coaxial or independent, meaning that their attracting-repelling fixed point pairs on the Gromov boundary of the free splitting complex are either equal or disjoint as sets. Each alternative is characterized in terms of attracting laminations; in particular, an outer automorphism is loxodromic if and only if it has a filling attracting lamination. As an application, each attracting lamination determines its corresponding repelling lamination independent of the outer automorphism. As part of this study, we describe the structure of the subgroup of O u t ( F n ) \mathsf {Out}(F_n) that stabilizes the fixed point pair of a given loxodromic outer automorphism, and we give examples which show that this subgroup need not be virtually cyclic. As an application, the action of O u t ( F n ) \mathsf {Out}(F_n) on the free splitting complex is not acylindrical, and its loxodromic elements do not all satisfy the weak proper discontinuity (WPD) property of Bestvina and Fujiwara.