This work offers a historical reading of the genesis of special relativity by placing the contributions of Lorentz, Poincare, and Einstein within their scientific and editorial context. It highlights the importance of the German periodical Beiblatter zu den Annalen der Physik as a key channel for the dissemination of international scientific research. The perspective advanced here is that the true revolution did not lie in special relativity itself, but in Maxwell's electrodynamics. Special relativity thus appears as the necessary expression of a framework already transformed by the universality of the speed of light.
Dam is an essential structure in hydraulic engineering, and its surface cracks pose significant threats to its integrity, impermeability, and durability. Automated crack detection methods based on computer vision offer substantial advantages over manual approaches with regard to efficiency, objectivity and precision. However, current methods face challenges such as misidentification, discontinuity, and loss of details when analyzing real-world dam crack images. These images often exhibit characteristics such as low contrast, complex backgrounds, and diverse crack morphologies. To address the above challenges, this paper presents a pure Vision Transformer (ViT)-based dam crack segmentation network (DCST-net). The DCST-net utilizes an improved Swin Transformer (SwinT) block as the fundamental block for enhancing the long-range dependencies within a SegNet-like encoder–decoder structure. Additionally, we employ a weighted attention block to facilitate side fusion between the symmetric pair of encoder and decoder in each stage to sharpen the edge of crack. To demonstrate the superior performance of our proposed method, six semantic segmentation models have been trained and tested on both a self-built dam crack dataset and two publicly available datasets. Comparison results indicate that our proposed model outperforms the mainstream methods in terms of visualization and most evaluation metrics, highlighting its potential for practical application in dam safety inspection and maintenance.
This paper Various studies cited in the literature deal with the classic problem of obstacle coverage, where the deployment environment, sensor nodes, and base stations have characteristics that are considered perfect but suffer from various flaws in the real world. This paper presents other barrier coverage types ranked in a new classification based on linear and nonlinear barrier coverage according to deterministic and insecure environments, and enumerates some of the different current and future challenges of these coverage types and connectivity in WSNs.
I employ methods from derived algebraic geometry to give a uniform moduli-theoretic construction of special cycle classes on integral models many Shimura varieties of Hodge type, including unitary, quaternionic, and orthogonal Shimura varieties. All desired properties of these cycles, even for those corresponding to degenerate Fourier coefficients under the Kudla correspondence, follow naturally from the construction. I formulate Kudla's modularity conjectures in this general framework, and give some preliminary evidence towards their validity.
D. J. Sand, S. K. Sarbadhicary, C. Pellegrino
et al.
We present deep Chandra X-ray observations of two nearby Type Ia supernovae, SN 2017cbv and SN 2020nlb, which reveal no X-ray emission down to a luminosity $L_X$$\lesssim$5.3$\times$10$^{37}$ and $\lesssim$5.4$\times$10$^{37}$ erg s$^{-1}$ (0.3--10 keV), respectively, at $\sim$16--18 days after the explosion. With these limits, we constrain the pre-explosion mass-loss rate of the progenitor system to be $\dot{M}$$<$7.2$\times$10$^{-9}$ and $<$9.7$\times$10$^{-9}$ M$_{\odot}$ yr$^{-1}$ for each (at a wind velocity $v_w$=100 km s$^{-1}$ and a radius of $R$$\approx$10$^{16}$ cm), assuming any X-ray emission would originate from inverse Compton emission from optical photons up-scattered by the supernova shock. If the supernova environment was a constant density medium, we find a number density limit of n$_{CSM}$$<$36 and $<$65 cm$^{-3}$, respectively. These X-ray limits rule out all plausible symbiotic progenitor systems, as well as large swathes of parameter space associated with the single degenerate scenario, such as mass loss at the outer Lagrange point and accretion winds. We also present late-time optical spectroscopy of SN 2020nlb, and set strong limits on any swept up hydrogen ($L_{Hα}$$<$2.7$\times$10$^{37}$ ergs s$^{-1}$) and helium ($L_{He, λ6678}$$<$2.7$\times$10$^{37}$ ergs s$^{-1}$) from a nondegenerate companion, corresponding to $M_{H}$$\lesssim$0.7--2$\times$10$^{-3}$ M$_{\odot}$ and $M_{He}$$\lesssim$4$\times$10$^{-3}$ M$_{\odot}$. Radio observations of SN 2020nlb at 14.6 days after explosion also yield a non-detection, ruling out most plausible symbiotic progenitor systems. While we have doubled the sample of normal type Ia supernovae with deep X-ray limits, more observations are needed to sample the full range of luminosities and sub-types of these explosions, and set statistical constraints on their circumbinary environments.
Mikkel T. Kristensen, Kevin Pimbblet, Samantha Penny
This study aims to explore the relation between dwarf galaxies ($M_* \leq 5\times10^9 M_\odot$) with AGNs and their environment by comparing neighbourhood parameters of AGN and non-AGN samples. Using the NASA-Sloan Atlas, both the local environment and the immediate environment of dwarf galaxies with $z \leq 0.055$ are analysed. Of the 145,155 galaxies in the catalogue, 62,258 of them are classified as dwarf galaxies, and by employing two AGN selection methods based on emission line fluxes (BPT and WHAN), 4,476 are found to have AGN characteristics in their optical spectra. Regardless of selection method, this study finds no discernible differences in environment between AGN and non-AGN host dwarf galaxies and these results indicate that environment is not an important factor in triggering AGN activity in dwarf galaxies. This is in line with existing literature on environments of regular galaxies with AGNs and suggests universality in terms of reaction to environment across the mass regime. The biases of AGN selection in low-mass galaxies, and the biases of different measures of environment are also considered. It is found that there are several mass-trends in emission line ratios and that the SDSS fiber covers galaxies non-uniformly with redshift. These biases should be accounted for in future work by possibly including other wavelength regimes or mass-weighting of emission line ratios. Lastly, a discussion of the environment estimation methods is included since they may not gauge the desired properties due to factors such as time delay or using loosely constrained proxy parameters.
[Context & Motivation] Adaptive systems are an important research area. The dominant reason for adaptivity in systems are changes in the environment. Thus, it is an important question how to model the environment and how to determine the necessary information on this environment in the requirements engineering phase. [Question/ Problem] There is so far relatively little explicit study of the notion of environment models in software engineering research. [Principal ideas/ Results] In this paper, we present a systematic literature review with the goal to determine the state of the art in environment modeling for adaptive systems, in particular from a requirements perspective. We discuss the goals of the approaches, the modeling concepts, as well as the methodology aspects of environment modeling in our survey. [Contribution] As major result of our survey, we provide a meta-model of existing environment modeling concepts. As a negative finding - and a research opportunity - we find that so far methodological aspects of environment modeling have received very little attention.
Preserving quantum coherence is fundamental challenge in the field of quantum computation. Here, I investigate the frozen discord phenomenon and non-Markovianity for qubits experiencing local dephasing in a classical environment. The quantum discord of a certain initial bipartite state, independently interacting with stochastic Gaussian fields, can be frozen for a finite time. The preservation of discord is shown to be intimately related to the backflow of information from the environment. The relevant result for quantum dephasing environment is compared.
This contribution is motivated by old and recent works on matrix powers and their applications on combinatorial sequences. We give in this paper the $s$-th powers and the inverses for special upper triangular matrices and the $s$-th powers for special non-triangular matrices. The used tools are Lagrange inversion formula and the partial Bell polynomials.
We obtain necessary conditions for the existence of special Kähler structures with isolated singularities on compact Riemann surfaces. We prove that these conditions are also sufficient in the case of the Riemann sphere and, moreover, we determine the whole moduli space of special Kähler structures with fixed singularities. The tool we develop for this aim is a correspondence between special Kähler structures and pairs consisting of a cubic differential and a hyperbolic metric.
In this paper we give a classification of special endomorphisms of nil-manifolds: Let $f:N/Γ\rightarrow N/Γ$ be a covering map of a nil-manifold and denote by $A:N/Γ\rightarrow N/Γ$ the nil-endomorphism which is homotopic to $f$. If $f$ is a special $TA$-map, then $A$ is a hyperbolic nil-endomorphism and $f$ is topologically conjugate to $A$.
When we were invited by the editors of Sustainability to put together a special edition on “Environment in Sustainable Development” our first reaction was to question whether this was really needed. After all, the environment has long been regarded as a central plank in sustainability and there are countless articles and books published on an annual basis that explore the impact of our economic and social activities on our environment. Just what is it that a special edition can achieve? What new angles could we hope to provide? Our initial thinking was to link the special edition to a particular, almost unique, location in time rather than space. We are in the process of recovering, albeit stuttering, from the deepest economic crash experienced by the European and North American economies. The crash has brought some national economies to their knees and, if economic commentators are to be believed, almost destroyed the Euro. Recovery from that crash has been slow and it is arguable whether at the time of writing this has developed much momentum. There is still the skewed perception that prosperity equals economic growth and that economic growth can take place without real (sustainable) development or by simply implementing austerity measures and surely without people’s participation. An analogy from National Parks worldwide is when conservation agencies try to enforce protection without local people’s support. All such attempts have either failed or resurrected only once people’s involvement was secured and guaranteed. The unidirectional austerity measures imposed mainly in the countries of southern Europe have destroyed social cohesion leaving deeply wounded societies, while at the same time have also put up for grabs important assets (including natural capital) in each of these countries and therefore in jeopardy even their long term recovery.
The special theory of relativity does not predict the existence of photons (quanta of electromagnetic radiation). However, it is demonstrated here that it follows from the special theory of relativity that if photons do exist---and we know that they do---then their energy must be proportional to their frequency. This means that the Planck-Einstein formula E=hν follows just from some results of the special theory of relativity and the assumption of the particle--wave duality.
We show that every bounded hyperconvex Reinhardt domain can be approximated by special polynomial polyhedra defined by homogeneous polynomial mappings. This is achieved by means of approximation of the pluricomplex Green function of the domain with pole at the origin.
We study a general class of random walks driven by a uniquely ergodic Markovian environment. Under a coupling condition on the environment we obtain strong ergodicity properties and concentration inequalities for the environment as seen from the position of the walker, i.e the environment process. We also obtain ergodicity of the uniquely ergodic measure of the environment process as well as continuity as a function of the jump rates of the walker. As a consequence we obtain several limit theorems, such as law of large numbers, Einstein relation, central limit theorem and concentration properties for the position of the walker.
In [3] Bege introduced the generalized Apostol's Mobius functions. In this paper we are presenting new properties of this functions. By introducing the special set of k-free numbers we have obtained some asymptotic formulas for the partial sums of these functions.