Miracle-dz/UniFAR-FTUs huggingface dataset:
Hierarchical model generation for architecture reconstruction using laser-scanned point clouds

Abstract. Architecture reconstruction using terrestrial laser scanner is a prevalent and challenging research topic. We introduce an automatic, hierarchical architecture generation framework to produce full geometry of architecture based on a novel combination of facade structures detection, detailed windows propagation, and hierarchical model consolidation. Our method highlights the generation of geometric models automatically fitting the design information of the architecture from sparse, incomplete, and noisy point clouds. First, the planar regions detected in raw point clouds are interpreted as three-dimensional clusters. Then, the boundary of each region extracted by projecting the points into its corresponding two-dimensional plane is classified to obtain detailed shape structure elements (e.g., windows and doors). Finally, a polyhedron model is generated by calculating the proposed local structure model, consolidated structure model, and detailed window model. Experiments on modeling the scanned real-life buildings demonstrate the advantages of our method, in which the reconstructed models not only correspond to the information of architectural design accurately, but also satisfy the requirements for visualization and analysis.
Limit measures for affine cellular automata

Let \mathbb{M} be a monoid (e.g. \mathbb{N}, \mathbb{Z}, or \mathbb{M}^D), and \mathcal{A} an abelian group. \mathcal{A}^\mathbb{M} is then a compact abelian group; a linear cellular automaton (LCA) is a continuous endomorphism \mathfrak{F}:\mathcal{A}^\mathbb{M}\longrightarrow\mathcal{A}^\mathbb{M} that commutes with all shift maps. Let \mu be a (possibly non-stationary) probability measure on \mathcal{A}^\mathbb{M}; we develop sufficient conditions on \mu and \mathfrak{F} so that the sequence \{\mathfrak{F}^N\mu\}_{N=1}^\infty weak* converges to the Haar measure on \mathcal{A}^\mathbb{M} in density (and thus, in Cesàro average as well). As an application, we show that, if \mathcal{A}=\mathbb{Z}_{/p} (p prime), \mathfrak{F} is any ‘non-trivial’ LCA on \mathcal{A}^{(\mathbb{Z}^D)}, and \mu belongs to a broad class of measures (including most Bernoulli measures (for D \geq 1) and ‘fully supported’ N-step Markov measures (when D=1)), then \mathfrak{F}^N\mu weak* converges to the Haar measure in density.
Doppler-free spectroscopy at a glass-vapour interface by saturated selective reflection at near normal incidence

Doppler-free spectra of gas phase atoms near a glass-vapour interface are obtained by monitoring the reflection of a probe beam-instead of its transmission-in three-level saturation spectroscopy. Experiments performed on the 3S-3P-4D cascade system of Na have allowed the authors to monitor two-photon-induced saturated dispersion of Na atoms.
Innovative Grid-Based Vorticity–Velocity Solver for Analysis of Vorticity-Dominated Flows

Unsteady vorticity-dominated flows are prevalent in a wide variety of engineering applications and are particularly challenging to predict efficiently. Perhaps in no other application is this more apparent than rotorcraft, where prediction is complicated by a wide variety of interactional aerodynamics between strong vortical wakes shed from rotating components and various bodies and wings immersed in the flow. While conventional computational fluid dynamics methods are equipped with the modeling capabilities to support these flow behaviors, they are subject to significant numerical diffusion whose practical import is that high computational costs involving large grids, complex adaptation methods, and high interpolation orders are required to produce sufficiently accurate simulations and prevent the artificial diffusion of vortical structures. Hybrid computational fluid dynamics methods that couple a body-fitted solver to a vorticity–velocity method hold considerable promise in alleviating these costs whil.
The retraction of the edge of a planar liquid sheet

Our objective is to investigate the motion of a free two-dimensional edge of a liquid sheet, which recedes and accumulates fluid as it is pulled back toward the bulk of the sheet due to surface tension. In the long time limit, the velocity of this edge reaches a constant value given by Taylor [Proc. R. Soc. London, Ser. A 253, 313 (1959)] and Culick [J. Appl. Phys. 31, 1128 (1960)], independent of the fluid viscosity. The way this value is reached, however, depends on the viscosity. In order to follow quantitatively the acceleration process, time-dependent numerical simulations of the two-dimensional Navier–Stokes equations have been performed. For inertia-dominated flow situations, the results show that the motion of the rim is relatively well characterized by a global momentum balance. However, if viscous effects are dominant, the rim is shown to extend far out into the film. In this case, the decrease in film thickness toward the undisturbed film can be described quite precisely by another one-dimensional model. By comparison of the individual contributions to the energy balances, following from numerical computation and from the global momentum balance, a closer look has also been taken on the inner mechanism of the rim formation. Finally, on the basis of the performed simulations, a stability criterion for a moving liquid curtain of finite length is derived, which determines whether a newly formed free rim leads to a break-up of the curtain.
Josephson broadband spectroscopy to 1 THz

We demonstrate the operation of a ‘‘Josephson Broadband Spectrometer’’ (JOBS) with a frequency range and bandwidth of 1 THz. The JOBS uses the inherent frequency tuning of the Josephson oscillations (f=2 eV/h) as a probe of the complex impedance environment, ZL(f), of the Josephson junction. Spectra taken of microstrip resonators (YBa2Cu3O7/SiO/Au) display up to nine harmonic resonances corresponding to a bandwidth of 1000 GHz. We find the surface resistance of YBa2Cu3O7 to scale as f2 over this frequency range, whereas the London penetration depth is frequency independent. The upper frequency limit of the measurement is set by the resonator loss whereas the JOBS presumably has an even larger intrinsic bandwidth.
Effect of wollastonite microfiber on the performance of engineered cementitious composites

The effects of 75μm wollastonite microfibers on the workability, mechanical properties and shrinkage properties of cementitious composites were studied by mechanical and shrinkage tests. The results show that the addition of microfiber reduces the fluidity of fresh mixture, but appropriate content can still meet the needs of self-compaction. WF has no gain effect on the compressive strength of the mixture, but when the dosage is 20%~30%, the flexural strength and tensile strength can be significantly increased by 87% and 28%. The shrinkage test indicates that WF has a good inhibiting effect on shrinkage deformation. It can be used as a good mineral admixture in ECC.
A family of random sup-measures with long-range dependence

A family of self-similar and translation-invariant random sup-measures with long-range dependence are investigated. They are shown to arise as the limit of the empirical random sup-measure of a stationary heavy-tailed process, inspired by an infinite urn scheme, where same values are repeated at several random locations. The random sup-measure reflects the long-range dependence nature of the original process, and in particular characterizes how locations of extremes appear as long-range clusters represented by random closed sets. A limit theorem for the corresponding point-process convergence is established.
A Fast Orthoimage Mosaic Method for Application of Grid

Traditional orthoimage mosaic methods do not perform well in computational speed and geometric precision. This paper proposed a fast orthoimage mosaic method for the application of grid. First of all, down-sample the original images and extracts feature, and adopt SANSAC to estimate the relative initial homography; second, refine homography matrix by Levenberg-Marquardt method and use the sparse bundle adjustment method to estimate the precise homography matrix; Third, passed the homography matrix to the original level of image by the homography relationship of the down-sampling and original image. Finally, synthesize the mosaic image. Our experiments showed that the method combined the down-sampling homography relationship of original image with sparse bundle adjustment organically, which effectively improved the speed and obtained geometric seamless mosaic.
High performance Al bi-layer wire-grid polarizer for deep-ultraviolet to infrared: modeling and design

Metallic wire-grid polarizers (WGP) transmit TM-polarized light (transverse magnetic) and reflect TE polarization (transverse electric) efficiently. They are compact, planar and compatible with integrated circuit (IC) fabrication, which simplifies their use as optical components in nanophotonic, fiber optic, display, and detector devices. In this work, Al bi-layer WGPs were designed and numerically simulated using finite element methods. Optical properties of the polarizers were analyzed in the deep-ultraviolet (DUV) to infrared (IR) regions. It was observed that Al bi-layer WGPs show broadband and high TM transmission and extinction ratio. A comparison of the performances of single and bi-layer WGPs show that the latter is highly advantageous over the former one. An extensive study of the dependence of the optical properties of single and bi-layer WGPs on structural parameters, such as period, metal thickness, and, duty cycle (DC), is provided. Optimal structural parameters are obtained within the feasible parameters in terms of nanofabrication. An Al bi-layer polarizer with a period of 80 nm and a metal layer thickness of 40 nm showed transmission up to 80% and extinction of 40 dB (104) and broadband polarizing behavior down to a wavelength of 250 nm.
Ramsey theory and chromatic numbers.

Let χ(G) denote the chromatic number of a graph G. For positive integers nίf n2, , nk (k ̂ 1) the chromatic Ramsey number χ(nίf n2, , nk) is defined as the least positive integer p such that for any factorization Kp — U*=i Gif χ{Gt) Ξ> w* for at least one i,l ^i ^k. It is shown that x(nu n2, , nk) = 1 + ΓR=i (nt — 1). The vertex-arboricity a(G) of a graph G is the fewest number of subsets into which the vertex set of G can be partitioned so that each subset induces an acyclic graph. For positive integers nlt n2, , w* (ft ^ 1) the vertexarboricity Ramsey number a(nltn2, ,nk) is defined as the least positive integer p such that for any factorization Kp — U*=i Gi> d(Gt) ̂ Ύii for at least one i, 1 rg % <Ξ k. It is shown that a(nlt n2, , nk) = 1 + 2k ΓR=i (nt — 1).
Nonlinear stability results for the modified Mullins–Sekerka and the surface diffusion flow

It is shown that any three-dimensional periodic configuration that is strictly stable for the area functional is exponentially stable for the surface diffusion flow and for the Mullins-Sekerka or Hele-Shaw flow. The same result holds for three-dimensional periodic configurations that are strictly stable with respect to the sharp-interface Ohta-Kawaski energy. In this case, they are exponentially stable for the so-called modified Mullins-Sekerka flow.
Isometry groups with radical, and aspherical Riemannian manifolds with large symmetry, I

Every compact aspherical Riemannian manifold admits a canonical series of orbibundle structures with infrasolv fibers which is called its infrasolv tower. The tower arises from the solvable radicals of isometry group actions on the universal covers. Its length and the geometry of its base measure the degree of continuous symmetry of an aspherical Riemannian manifold. We say that the manifold has large symmetry if it admits an infrasolv tower whose base is a locally homogeneous space. We construct examples of aspherical manifolds with large symmetry, which do not support any locally homogeneous Riemannian metrics.
Influence of higher and sub harmonics in time reversed Lamb wave generated and sensed using de-bonded piezoelectric wafers

Time reversed lamb wave based damage detection is very suitable for online Structural Health Monitoring (SHM). Non linear higher and sub harmonics are generated in the Lamb waves which are generated and sensed using partially de-bonded piezoelectric wafer transducers (PWT) from the host plate. Experimental and numerical studies of the influence of higher harmonics in time reversed reconstruction of Lamb wave in an aluminium plate are presented in this work. 2D finite element simulations are carried out using de-bonded actuator and receiver separately and the influence of actuator de-bonding is found to have more influence on time reversed reconstruction. Experiments are done for transducer de-bonding and the in uence of Lamb wave amplitude for non-linear interaction is studied. Influence of de-bonding length on change in reconstruction is also studied.
On the number of finite algebraic structures

We prove that every clone of operations on a finite set A, if it contains a Malcev operation, is finitely related -- i.e., identical with the clone of all operations respecting R for some finitary relation R over A. It follows that for a fixed finite set A, the set of all such Malcev clones is countable. This completes the solution of a problem that was first formulated in 1980, or earlier: how many Malcev clones can finite sets support? More generally, we prove that every finite algebra with few subpowers has a finitely related clone of term operations. Hence modulo term equivalence and a renaming of the elements, there are only countably many finite algebras with few subpowers, and thus only countably many finite algebras with a Malcev term.
Ultraviolet and optical spectrum studies of Lambda Andromedae - Evidence for atmospheric inhomogeneities

To pursue the study of solar phenomena in cool stars, chromospheric activity in Lambda Andromedae (HD 222107 has been investigated). This binary, whose primary star is G7-G8 IV-III, shows strong chromospheric emissions and is related to the RS CVn-type systems. The first quantitative measurements of chromospheric and solar-type transition-region emissions as a function of the variable starspot and active-region phenomena in an RS CVn star are presented. The presence of optically darker starspots in Lambda And coincides with the brightening of both Ca II K emission and the ultraviolet transition-region lines. The ultraviolet and optical spectra show attributes of starspots, active regions, and mass flow. Analogies to solar activity are successful in explaining these observations.
Maximum mass ratio of am CVn-type binary systems and maximum white dwarf mass in ultra-compact x-ray binaries (addendum - Serb. Astron. J. No. 183 (2011), 63)

We recalculated the maximum white dwarf mass in ultra-compact X-ray binaries obtained in an earlier paper (Arbutina 2011), by taking the effects of super-Eddington accretion rate on the stability of mass transfer into account. It is found that, although the value formally remains the same (under the assumed approximations), for white dwarf masses M2 >~0.1MCh mass ratios are extremely low, implying that the result for Mmax is likely to have little if any practical relevance.
Time-dependent models of radiatively driven stellar winds. I - Nonlinear evolution of instabilities for a pure absorption model

Numerical radiation-hydrodynamics simulations of the nonlinear evolution of instabilities in radiatively driven stellar winds have been performed. The results show a strong tendency for the unstable flow to form rather sharp rarefactions in which the highest speed material has very low density. The qualitative features of the model agree well with the reqirements of displaced narrow absorption components in UV lines. 56 references.
Predicting daily highs and lows of exchange rates: a cointegration analysis

This article presents empirical evidence that links the daily highs and lows of exchange rates of the US dollar against two other major currencies over a 15 year period. We find that the log high and log low of an exchange rate are cointegrated, and the error correction term is well-approximated by the range, which is defined as the difference between the log high and log low. We further assess the empirical relevance of jointly analyzing the highs, lows and the ranges by comparing the range forecasts generated from the cointegration framework with those from random walk and autoregressive integrated moving average (ARIMA) specifications. The ability of range forecasts as predictors of implied volatility for a European style currency option is also evaluated. Our results show that aside from a limited set of exceptions, the cointegration framework generally outperforms the random walk and ARIMA models in an out-of-sample forecast contest.
Effectiveness of Abdominal Ultrasonography for Improving the Prognosis of Pancreatic Cancer during Medical Checkup: A Single Center Retrospective Analysis

Recent advancements in surgical and anti-cancer therapies have provided significant hope of long survival in patients with pancreatic cancer (PC). To realize this hope, routine medical checkups of asymptomatic people should be performed to identify operable PCs. In this study, we evaluated the efficacy of medical checkups using abdominal ultrasonography (US). We retrospectively analyzed 374 patients with PC at our institute between 2010 and 2021. We divided these patients into several groups according to the diagnostic approach and compared their background and prognosis. These groups comprised PCs diagnosed through (a) symptoms, 242 cases; (b) US during medical checkup for asymptomatic individuals, 17; and other means. Of the 374 patients, 192 were men (51.3%), and the median age was 74 years (34–105). Tumors were located in the pancreatic tail in 67 patients (17.9%). Excision ratio and 5-year survival rate were significantly better in group (b) than in (a) (58.8% vs. 23.1%, p < 0.01 and 42.2% vs. 9.4%, p < 0.001, respectively). The prognosis of patients diagnosed using US during medical checkup was better than that of patients identified through symptomatic presentation of PC. US for asymptomatic individuals with PC might be one of the useful modalities for promoting better prognosis of PCs.
Measurements of a high-luminosity flame structure by a shuttered PIV system

It is difficult to measure the velocity distribution inside a high-luminosity flame by using the particle image velocimetry (PIV) system with a double-shutter mode CCD camera. The second raw image of the PIV image pair is usually contaminated by flame emission. The main cause of the problem is an excess exposure time which lets the flame emission overlap the particle image in the second frame. If the flame-contamination problem is not significant, for example in faint flames, digital image processing can improve the image to an acceptable level. Nevertheless, when the PIV technique is applied to high-luminosity flames, the second raw particle image would be contaminated by flame emission. In this paper, incorporating a mechanical shutter in the PIV system with a double-shutter CCD camera is proposed to improve PIV measurements in high-luminosity flames. Measurements in faint, high-luminosity as well as very bright flames were tested. The results show that the present setup can accurately resolve the flow velocity field inside the flame cone, through the flame and in the post flame zone for all the flame conditions analyzed. The velocity distributions and streamline patterns measured by the present equipment are reasonable and meaningful.
Permutohedra, configuration spaces and spineless cacti

Zhang, Yongheng PhD, Purdue University, May 2015. Permutohedra, Configuration Spaces and Spineless Cacti. Major Professor: Ralph Kaufmann. It has been known that the configuration space F (R, n) of n distinct ordered points in R deformation retracts to a regular CW complex with n! permutohedra Pn as the top dimensional cells. In this paper, we show that there exists a similar but di↵erent permutohedral structure of the space Cact(n) of spineless cacti with n lobes. Based on these structures, direct homotopy equivalences between F (R, n) and Cact(n) are then given. It is well known that the little 2-discs space D2(n) is homotopy equivalent to F (R, n). Our results give partial combinatorial and geometrical interpretation of the equivalences between D2 and Cact.
The Nature of the Extended H I Gas around NGC 4449: The Dr. Jekyll/Mr. Hyde of Irregular Galaxies

We present interferometric H I 21 cm line observations of the extended gas around the irregular galaxy NGC 4449 covering 67' on the sky at a resolution of ~1'. The main star-forming body of NGC 4449 is relatively normal for a Magellanic irregular galaxy, but the galaxy is unusual in that it has two counterrotating gas systems and H I that extends to 6 times the Holmberg radius. Our new, detailed H I maps of this extended gas show that most of the extended H I is located in large, highly structured, extended clouds and very long streamers. We compare NGC 4449 with other systems in the context of possible models for the origin of these structures, the most likely of which involves an interaction with another galaxy. Thus, NGC 4449 no longer fits the standard picture of an irregular galaxy quietly evolving in isolation.
Embedded ultra-high stability flexible transparent conductive films based on exfoliated graphene-silver nanowires-colorless polyimide

Transparent conductive films with high stability were prepared by embedding silver nanowires in colorless polyimide and adding a protective layer of exfoliated graphene. The films exhibit great light transmission and conductivity with a sheet resistance of 22 Ω sq−1 at transmittance of 83%. Due to its special embedded structure, the conductive layer can withstand several peeling experiments without falling off. In addition, the most outstanding advantage is the ultra-high stability of the films, including high mechanical robustness, strong chemical corrosion resistance and high operating voltage capacity. The organic light-emitting diode devices prepared based on this transparent conductive electrode exhibit comparable efficiency to indium tin oxide (ITO) based devices, with C.E. max = 2.78 cd A−1, P −1 . E. max = 1.89 lm W−1, EQE max = 0.89%. Moreover, the efficiencies were even higher than that of ITO devices when the operating voltage of the device exceeds 5 V. The above performances show that the transparent conductive electrode based on this structure has high potential for application in organic electronic devices.
The Effect of Transmission-Line Dynamics on Grid-Forming Dispatchable Virtual Oscillator Control

In this paper, we analyze the effect of transmission line dynamics on grid-forming control for inverter-based ac power systems. In particular, we investigate a dispatchable virtual oscillator control (dVOC) strategy that was recently proposed in the literature. When the dynamics of the transmission lines are neglected, that is, if an algebraic model of the transmission network is used, dVOC ensures almost global asymptotic stability of a network of ac power inverters with respect to a prespecified solution of the ac power-flow equations. While this approximation is typically justified for conventional power systems, the electromagnetic transients of the transmission lines can compromise the stability of an inverter-based power system. In this paper, we establish explicit bounds on the controller set-points, branch powers, and control gains that guarantee almost global asymptotic stability of dVOC in combination with a dynamic model of the transmission network.