Miracle-dz/UniFAR-FTUs huggingface dataset:
Calibration, Recognition, and Shape from Silhouettes of Stones

Multi-view shape-from-silhouette systems are increasingly used for analysing stones. This thesis presents methods to estimate stone shape and to recognise individual stones from their silhouettes. Calibration of two image capture setups is investigated. First, a setup consisting of two mirrors and a camera is introduced. Pose and camera internal parameters are inferred from silhouettes alone. Second, the configuration and calibration of a high throughput multi-camera setup is covered. Multiple silhouette sets of a stone are merged into a single set by inferring relative poses between sets. This is achieved by adjusting pose parameters to maximise geometrical consistency specified by the epipolar tangency constraint. Shape properties (such as volume, flatness, and elongation) are inferred more accurately from the merged silhouette sets than from the original silhouette sets. Merging is used to recognise individual stones from pairs of silhouette sets captured on different occasions. Merged sets with sufficient geometrical consistency are classified as matches (produced by the same stone), whereas inconsistent sets are classified as mismatches. Batch matching is determining the one-to-one correspondence between two unordered batches of silhouette sets of the same batch of stones. A probabilistic framework is used to combine recognition by merging (which is slow, but accurate) with the efficiency of computing shape distribution-based dissimilarity values. Two unordered batches of 1200 six-view silhouette sets of uncut gemstones are correctly matched in approximately 68 seconds (using a 3.2 GHz Pentium 4 machine). An experiment that compares silhouette-based shape estimates with mechanical sieving demonstrates an application using the developed methods. A batch of 494 garnets is sieved 15 times. After each sieving, silhouette sets are captured for sub-batches in each bin. Batch matching is used to determine the 15 sieve bins per stone. Better estimates of repeatability, and better understanding of the variability of the sieving process is obtained than if only histograms (the natural output of sieving) were considered. Silhouette-based sieve emulation is found to be more repeatable than mechanical sieving.
On computing MTBF for a k-out-of-n:G repairable system

It is often necessary to calculate the MTBF (mean time between failures) quickly in order to make timely design decisions. An important system for which such calculations must be made is a k-out-of-n:G parallel system with unlimited repair and exponential interfailure and repair times at the unit level. Although a general formula is known, it is not easily remembered or derived. A method for deriving a formula for MTBF in this situation that is easily reproduced quickly by remembering a few simple concepts is presented. >
Fast Fourier transform techniques for efficient simulation of Z-scan measurements

Fast Fourier beam–propagation methods (BPM’s) for simulating the roles of internal refractive effects and external propagation from nonlinear media are introduced. These techniques are applied to model picosecond Z-scan measurements for the induced absorber, the dye Chloro-Aluminum Phthalocyanine, at 532 nm. Within the thin-sample approximation an incident Gaussian beam is taken to experience a change in phase profile on propagation through the medium but remains of Gaussian amplitude profile. Outside this approximation one must determine both the phase and the amplitude profiles at the sample exit face that are due to the influence of nonlinear refraction (and nonlinear absorption) on the beam propagating through the medium. The BPM technique allows this to be achieved efficiently, and the external propagation technique enables a single discrete fast Fourier transform to be used to describe the subsequent external propagation of the non-Gaussian-shaped beams. The analysis is especially useful for such self-enhancing nonlinearities as one would wish to exploit in optical limiting.
Multiparticle collision dynamics simulation of a polymer in a viscous fluid

We perform a hybrid molecular dynamics simulation of a polymer immersed in a viscous liquid. Using the multiparticle collision dynamics algorithm to incorporate the hydrodynamic effects, we examine static and dynamic properties of a self-avoiding flexible polymer. The diffusion coefficient of the polymer is found to be proportional to N−ν, where N is the molecular weight of the polymer and ν = 3/5 is the swelling exponent, as predicted by the Zimm model. The velocity autocorrelation function of the center of mass of the polymer is obtained as a function of time t, which shows an algebraic decay as t−3/2 at long-time scales. Our results confirm the theoretical prediction for the dynamical properties of a polymer and show the validity of the hybrid simulation scheme in studying the dynamics of a polymer in a viscous fluid.
Maximum likelihood estimator for jitter noise models

High frequency sampling scopes suffer from both additive noise and time jitter. The classical techniques for identifying the additive noise and time jitter noise are based on linear least squares estimators. This work derives the maximum likelihood estimator and compares it performance with the least squares estimator. Simulation results show the gain in efficiency of the proposed method under practical conditions of the sampling scopes.
Fine-grained transfer learning based on deep feature decomposition for rotating equipment fault diagnosis

The study of transfer learning in rotating equipment fault diagnosis helps overcome the problem of low sample marker data and accelerates the practical application of diagnostic algorithms. Previously reported methods still require numerous fault data samples; however, it is unrealistic to obtain information about the different health states of rotating equipment under all operating conditions. In this paper, a two-stage, fine-grained, fault diagnosis framework is proposed for implementing fault diagnosis across domains of rotating equipment under the condition of no target domain data. Considering that the target domain is completely unknown, the main idea of this paper is to decompose multiple source domain depth features to identify domain-invariant categorical features common under different source domains and classify unknown target domains. More impressively, the problems of data imbalance and low signal-to-noise ratio can be properly solved in our network. Extensive experiments are conducted in two different case studies of rotating devices to validate the proposed method. The experiments show that the method in this paper achieves significant results on both bearing and gearbox health status classification tasks, outperforming other deep transfer learning methods.
The Likelihood Ratio Test for the Rank of a Cointegration Submatrix

This paper proposes a likelihood ratio test for rank deficiency of a submatrix of the cointegrating matrix. Special cases of the test include the one of invalid normalization in systems of cointegrating equations, the feasibility of permanent-transitory decompositions and of subhypotheses related to neutrality and long-run Granger noncausality. The proposed test has a chi-squared limit distribution and indicates the validity of the normalization with probability one in the limit, for valid normalizations. The asymptotic properties of several derived estimators of the rank are also discussed. It is found that a testing procedure that starts from the hypothesis of minimal rank is preferable. Copyright 2006 Blackwell Publishing Ltd.
Upernet optimisation and application to mousehole segmentation

The evaluation of grassland degradation is an important part of ecological conservation research, and rodent infestation is a significant factor in grassland degradation. The presence of a large number of mouseholes means that the environmental balance of grassland has been destroyed, so the coverage of mouseholes can be used as an evaluation method for grassland degradation levels. In this paper, the image segmentation method is used to segment the mousehole images, Upernet is used as the segmentation network, and Swin Transformer as the Backbone. FAM and FSM modules are added to the Upernet network to solve the target misalignment problem when upsampling the network. The mIoU is improved by 5.3% according to the experimental results.
Adaptive output feedback regulation for a class of uncertain nonlinear systems

In this paper, the problem of global state regulation by output feedback is investigated for a class of uncertain nonlinear systems satisfying some relaxed upper‐triangular‐type condition. Using a linear dynamic gain observer with two dynamic gains and introducing two appropriate change of coordinates, we give a constructive design procedure for the linear‐like output feedback stabilizing controller. It is proved that the proposed controller globally regulates all the states of the uncertain system and maintains global boundedness of the closed‐loop system. An example is provided to demonstrate the effectiveness of the proposed design scheme. Copyright © 2014 John Wiley & Sons, Ltd.
Quantum efficiencies of gold and copper photocathodes in the VUV and X-ray range

The quantum efficiency, η, of gold and copper photocathodes has been measured in the photon-energy range from 50 eV to 10 keV. The experiments were performed with monochromatized synchrotron radiation at the radiometry laboratories of the Physikalisch-Technische Bundesanstalt (PTB) at the electron storage rings BESSY I and BESSY II. Relative standard uncertainties of η lower than 0.036 were achieved using a cryogenic electrical-substitution radiometer as the primary detector standard. The samples were cleaned, stored and examined in an ultra-high-vacuum chamber. The quantum efficiency of cleaned gold and copper was found to be reproducible within 2 parts in 102 to 3 parts in 102. A simple model assumes to be proportional to the product of absorption coefficient, μ, and photon energy, hν. The relative course of the absorption coefficient was also measured with relative standard uncertainties below 0.04. As proportionality was only locally fulfilled, a more sophisticated model for quantum efficiency was developed.
Shape Reconstruction for Continuum Robot Based on Pythagorean Hodograph–Bézier Curve With IMU and Vision Sensors

The shape information is the key to realize real-time, accurate, and effective control of continuum robots. Traditional image processing method and start-to-end-point fitting method are combined. Inertial measurement unit (IMU) and camera are used to capture the end position and attitude information of continuum robot and do not rely on the acquisition of the global image to solve the problem of limited vision in a traditional image processing method. In addition, a new start-to-end-point fitting method is proposed, which is the Pythagorean hodograph—Bézier (PH-B) fitting method. The new method simplifies the solving steps of control points of fitting curve. The control points can be obtained only through the geometric relationship and do not need to rely on an optimization algorithm for iterative solution. This method has good shape fitting accuracy and applicability in the curvature range from 0° to 90° through the simulation analysis. A variety of experiments are designed to verify the results. The experimental results show that the maximum shape reconstruction error by the proposed method is about 2 mm. This proves the applicability of the PH-B method in the shape reconstruction of continuum robots.
Optical rotation of the shrunken multi-lamellar vesicle using optical tweezers

We study a geometrically anisotropic internal nano-layered structure of the shrunken multi-lamellar vesicle(SMLV) by using optical tweezers with a polarized beam. The SMLVs are synthesized from soybean asolectin by using gentle hydration method and has an optically birefringence property, known as a form birefringence. When a laser beam of optical tweezers with an elliptical polarization passes through the material with an optical birefringence, the ordinary and extraordinary components of the laser light experience different phase shift, respectively. Therefore, an optical torque due to the angular momentum conservation can be exerted on the optically birefringence material generating a rotational motion of the system. In this work we analyze the distance between the next bilayers of the membrane structure in SMLV from the experimentally measured data of the rotational motion and propose a simple model in which the SMLV is idealized as a multi-regularly-thin parallel plate structure.
Nonlinear stability and rupture of ultrathin free films

The nonlinear long‐wave stability and lifetimes of thin free films subjected to the excess Lifshitz–van der Waals (LW) forces are studied based on numerical solutions, and a weakly nonlinear theory (WNT), which neglects mode interactions. The WNT works best for the fastest growing (dominant) disturbances of small initial amplitudes, and also for relatively thick films. For such cases, the nonlinear viscous effects (stabilizing) and inertia (destabilizing) are usually less significant than the LW force (destabilizing), surface tension force, and the unsteady effects (both stabilizing). For large initial amplitudes, linearly stable disturbances can engender strong subcritical instabilities and film rupture due to the greatly enhanced LW forces, inertia and mode interactions.
Vortex structures in the near-field of inclined coaxial jets

A flow visualization study was carried out to study the near-field flow features of 45° and 60° inclined coaxial nozzles of area-ratios of 2.25 and 4 subjected to velocity-ratios of 0.5, 1 and 2. Laser cross-sections show that inclined vortex roll-ups are formed along both the inner and outer jet shear layers regardless of area- and velocity-ratios. Increase in inclineangle and velocity-ratio lead to intensifications of the near-field formation of and interactions between the vortex roll-ups. Strong vortex-pairings of the outer vortex roll-ups at velocity-ratios of 1 and 2 for area-ratio of 2.25 test case result in their large-scale entrainment into the primary jet streams. Increasing the area-ratio limits that phenomenon to occur only at velocity-ratio of 2 for the area-ratio of 4 test cases.
VIPERS view of the star formation history of early-type galaxies

We present studies over the relations between stellar mass, redshift and star formation history for a high quality sample of early-type galaxies (ETGs) observed by the by the VIMOS Public Extragalactic Redshift Survey (VIPERS). VIPERS is an ongoing Large Programme to map in detail the large-scale distribution of galaxies at 0:5 < z < 1:2 with a unique volume (24 deg2) and sampling rate (~= 45%). At this redshift, IPERS fills a unique niche in galaxy surveys, provides a exceptional opportunity to study galaxies and their evolution at an epoch when the Universe had approximately half its current age. VIPERS data set will become the z ~ 1 equivalent of current state-of-the-art local (z < 0:2) surveys, allowing us to compare measurements at these two different epochs on equal statistical footing. The final sample of this survey is going to reach nearly 100,000 galaxies. As the VIPERS sample contains ~ 15% of the early type galaxies with known spectroscopic redshift and a very good quality spectra, it is a perfect sample to study the star formation history based on their spectroscopic features. We show that there the age of stellar population is depending on the stellar mass and the redshift. Our results show that lower mass galaxies have young stellar populations, while higher mass ETGs are populated with old stars. This suggest that marginal star formation occurs in massive galaxies. This result is consistent with the observations of the local Universe. Moreover, this trend of evolution is preserved for the different redshift range between 0:4 < z < 1:2.
Large‐deformation and friction analysis of non‐linear elastic cable networks by second‐order cone programming

A new formulation is presented for equilibrium shape analysis of cable networks considering geometrical and material non‐linearities. Friction between cables and joint devices is also considered. The second‐order cone programming (SOCP) problem which has the same solution as that of minimization of total potential energy is solved to obtain the equilibrium configuration. The optimality conditions are derived to verify that the solution satisfies equilibrium conditions and friction laws. Since no assumption on stress state is needed in the proposed method, no process of trial and error is involved. No effort is required to develop any analysis software because SOCP can be solved by using the well‐developed software based on the interior‐point method. Copyright © 2002 John Wiley & Sons, Ltd.
Separatrix crossing: time-invariant potentials with dissipation

Strongly nonlinear oscillations in a double-well potential that cross a separatrix due to dissipation are analyzed. Away from the separatrix the nearly periodic oscillations are found using standard asymptotic techniques that are known to fail near the separatrix. The solution near the separatrix is represented as a large sequence of perturbed solitary pulses. The asymptotic behavior of this sequence is matched (forward and backward in time) to the nearly periodic oscillations. In this manner, the oscillations in the post-crossing region are connected, for the first time, to initial conditions. In particular, we determine the amplitude and the phase of the nonlinear oscillator after crossing the separatrix and show them to be sensitively dependent on the initial conditions. The shift between the critical times associated with the slow variation theory before and after crossing the separatrix is derived.
Network Effectiveness in Context

Increasingly, scholars and practitioners are interested in evaluating the effectiveness of interorganizational networks. We use a configuration approach to study network effectiveness. This research is a mixed-method study of 26 education networks in the United States. We measure network effectiveness by comparing 4th-grade literacy, 8th-grade literacy, and high-school graduation rates. We compare these scores with all school districts in the state using interrupted time series or parametric difference-in-differences approaches. Then, drawing from qualitative data from interviews and archives, we investigate the network governance, environmental characteristics, and theories of change associated with greater student achievement. We find three configurations associated with network effectiveness using fuzzy-set qualitative comparative analysis. One configuration combines decentralized governance with a project theory of change in the context of resource munificence. A second configuration associated with network effectiveness is to combine learning and systems alignment theories of change with smaller network size and resource munificence. The final configuration combines decentralized governance, a learning theory of change, less resource munificence, and larger network size and does not use a systems alignment theory of change. The results support the configurational approach, which suggests multiple configurations of factors in combination may result in network effectiveness.
An alternative approach for constructing small sample and limiting distributions of maximum likelihood estimators

We construct limiting and small sample distributions of maximum likelihood estimators (mle) from the property that they satisfy the first order condition (foc). The foc relates the mle of the analyzed model to the mle of an encompassing model and shows that the mle of the analyzed model is a realization from the limiting or small sample distribution of the mle of the encompassing model given that the foc holds. We can thus use the unique conditional (limiting or small sample) density of the mle of the encompassing model given that the foc holds to construct the limiting or small sample density/distribution of the mle of the analyzed model. To proof the validity of this approach and thus of the concept of an unique conditional density, we use it to construct the small sample and limiting distribution of the limited information mle and show that they are identical to resp. the sampling density and the expression discussed elsewhere in the literature. We analyze the further and relate it to existing expressions and show its limiting behavior in case of weak and strong instruments.
Denoising Method of Pipeline Leakage Signal Based on VMD and Hilbert Transform

In order to solve the problem of low localization accuracy of water supply pipeline leakage detection using acoustic emission signals, a noise reduction algorithm based on variational mode decomposition (VMD) and Hilbert transform is proposed in this paper. Firstly, the leakage signal is decomposed into several intrinsic mode functions (IMF) using VMD, and the number of decomposition layers is determined, and the IMF component is transformed by Hilbert to get the marginal spectrum, and the noise are preliminarily filtered according to the marginal spectrum characteristics and the cross-correlation coefficient. Secondly, the signal denoising is realized by using filtering technology and cross-correlation coefficient. Finally, the time delay estimation of the denoised signal is estimated and the location of the leakage point is calculated based on the positioning principle. In order to verify the performance of the algorithm, a water supply pipeline experiment platform for leakage simulation and leak location experiment was conducted. The cross-correlation algorithm, VMD-correlation coefficient algorithm, and the proposed algorithm are analyzed through simulation and experiment. The results show that compared with the other two algorithms, the proposed algorithm can effectively remove the noise in the leakage signal and improve the accuracy of leakage location.