Miracle-dz/UniFAR-FTUs huggingface dataset:
Three-dimensional registration and shape reconstruction from depth data without matching: A PDE approach

The widespread availability of depth sensors like the Kinect camera makes it easy to gather three-dimensional (3D) data. However, accurately and eﬃciently merging large datasets collected from diﬀerent views is still a core problem in computer vision. This question is particularly challenging if the relative positions of the views are not known, if there are few or no overlapping points, or if there are multiple objects. Here, we develop a method to reconstruct the 3D shapes of objects from depth data taken from diﬀerent views whose relative positions are not known. Our method does not assume that common points in the views exist nor that the number of objects is known a priori. To reconstruct the shapes, we use partial diﬀerential equations (PDE) to compute upper and lower bounds for distance functions, which are solutions of the Eikonal equation constrained by the depth data. To combine various views, we minimize a function that measures the compatibility of relative positions. As we illustrate in several examples, we can reconstruct complex objects, even in the case where multiple views do not overlap, and, therefore, do not have points in common. We present several simulations to illustrate our method including multiple objects, non-convex objects, and complex shapes. Moreover, we present an application of our PDE approach to object classiﬁcation from depth data.
Analysis and Computation of the $\mathcal {H}_2$ Norm of Delay Differential Algebraic Equations

We consider a class of dynamical systems described by linear delay differential algebraic equations (DDAEs) called strangeness free, which is broader than the class commonly studied within the control theory field. Two problems arise in the study of the <inline-formula><tex-math notation="LaTeX">$\mathcal {H}_2$</tex-math></inline-formula> norm of DDAEs: the first one is that it may be infinite even if the system is stable or has no seemingly feedthrough term, and the second one is the computation. In this paper, both problems are addressed. We provide a necessary and sufficient condition for the finiteness of the <inline-formula><tex-math notation="LaTeX">$\mathcal {H}_2$</tex-math></inline-formula> norm, which is based on controllability and observability properties of the delay-difference part of the system, and we present a formula for computing the <inline-formula><tex-math notation="LaTeX">$\mathcal {H}_2$</tex-math></inline-formula> norm whenever it is finite, which is obtained by means of a neutral-type system whose transfer matrix is equivalent to the transfer matrix of DDAEs.
A new five-dimensional four-wing hyperchaotic system with hidden attractor, its electronic circuit realisation and synchronisation via integral sliding mode control

This paper reports a new five-dimensional four-wing hyperchaotic system with hidden attractor. First, this paper discusses the dynamic properties of the new four-wing system with a detailed bifurcation analysis, coexistence of attractors and multistability, offset boosting, Lyapunov exponents, etc. It is shown that the new four-wing system has no rest point and thus it exhibits hidden attractor. The new four-wing system exhibits two positive Lyapunov characteristic exponents and a large value of Kaplan-Yorke dimension indicating high complexity of the system. We realise the dynamic equations of the new four-wing system with an electronic circuit and simulations via MultiSIM. As a control application, we derive new results for the complete synchronisation of the new four-wing system via integral sliding mode control. MATLAB simulations are adequately provided to illustrate modelling and applications of the new four-wing system with hyperchaotic four-wing attractor.
On Closed Six-Manifolds Admitting Metrics with Positive Sectional Curvature and Non-Abelian Symmetry

ON CLOSED SIX-MANIFOLDS ADMITTING METRICS WITH POSITIVE SECTIONAL CURVATURE AND NON-ABELIAN SYMMETRY Yuhang Liu Wolfgang Ziller We study the topology of closed, simply-connected, 6-dimensional Riemannian manifolds of positive sectional curvature which admit isometric actions by SU(2) or SO(3). We show that their Euler characteristic agrees with that of the known examples, i.e. S, CP, the Wallach space SU(3)/T 2 and the biquotient SU(3)//T . We also classify, up to equivariant diffeomorphism, certain actions without exceptional orbits and show that there are strong restrictions on the exceptional strata.
CLASSIFICADOR ENSEMBLE: UMA ABORDAGEM NÃO PARAMÉTRICA APLICADO À DETECÇÃO DE DIABETES

Se tratando de dados dicotomicos, isto e, que admitem somente duas respostas possiveis, os modelos supervisionados de aprendizado de maquina comumente utilizados sao: regressao logistica, arvores aleatorias e K–Nearest neighbor (KNN). No entanto, a depender dos dados, tais predicoes podem nao apresentar uma boa acuracia (> 70%). Surge entao, como alternativa aos modelos usuais, os classificadores ensemble (Gul & Perperoglou, 2018). O metodo ensemble e uma tecnica de aprendizado de maquina que combina o resultado de multiplos modelos em busca de produzir um melhor modelo preditivo. Existem varios algoritmos pre-fixados de classificadores ensemble, tais como: bagging, boosting, bayesian averaging, entre outros. No entanto, a escolha dos modelos preditivos base e a maneira que estes resultados serao combinados sao livres (Opitz & Maclin, 1999). Os classificadores ensemble sao uma classe de metodos utilizados para aumentar a acuracia do modelo com a juncao de modelos mais fracos, quando o emprego de metodos mais simples, separadamente, nao apresentam o resultado desejado. Para a aplicacao de metodos mais sofisticados para a predicao dos dados, faz-se necessario o uso de tecnicas iniciais que permitam o correto aproveitamento do modelo.
The Origin of Optical Contrast in Sb2Te3‐Based Phase‐Change Materials

The optical contrast between the crystalline and amorphous forms of phase‐change materials (PCMs) is so marked as to make it ideal for data storage. Various explanations have been given, including smearing of bands, changes in the local structural order and bonding, and resonant bonding. A consensus has not been reached. Herein, the dielectric function of crystalline and amorphous Sb2Te3, a topological insulator and prototype PCM, is studied using density functional theory and ellipsometry measurements; an expression for interplay between the crystalline electric field and the spin–orbit interaction on the valence band orbitals is derived. It is found that the crystalline electric field and spin–orbit interaction are responsible for this difference and the unusually large refractive index in the crystalline phase. Upon amorphization, a second‐order electronic phase transition is induced by the spin–orbit interaction's effect on the pz orbitals. This mechanism explains how a substantial optical gap can open in systems that have a small electronic band gap.
Analisis Lean Manufacturing Untuk Mengurangi Pemborosan Pada Produksi Teh Hitam CTC (Studi Kasus PT Perkebunan Nusantara XII Kebun Teh Wonosari, Malang)

PT Perkebunan Nusantara XII Kebun Teh Wonosari Malang memproduksi salah satu jenis teh yaitu teh hitam. Permasalahan yang dialami oleh PT Perkebunan Nusantara XII Kebun Teh Wonosari Malang adalah meningkatnya jumlah produk cacat beberapa tahun terakhir. Hasil produk tehnya tidak mencapai 80% target mutu produk yang diharapkan. Hal tersebut dibuktikan, pada tahun 2015 produksi hanya mencapai target mutu sebesar 67,29% dan tahun 2016 sebesar 73,44%. Permasalahan lain adalah proses waiting karena pengiriman bahan baku berupa pucuk teh yang akan diproduksi dibagi menjadi dua waktu pengiriman. Tujuan dari penelitian ini adalah untuk mengidentifikasi penyebab pemborosan (waste) pada proses produksi teh hitam dan memberikan usulan perbaikan untuk mengurangi pemborosan yang terjadi. Penelitian ini dilakukan dengan pendekatan lean manufacturing dengan alat bantu Value Stream Mapping (VSM) dan Value Stream Analysis Tool (VALSAT). VSM akan melakukan pemetaan aliran proses produksi sehingga dapat diketahui aktivitas non value added dan dapat dikurangi. Identifikasi pemborosan yang paling banyak terjadi akan dilakukan dengan bantuan kuesioner yang disebarkan pada value stream manager. Penelitian akan dilanjutkan dengan melakukan uji lanjutan berupa VALSAT untuk mengetahui penyebab pemborosan. Hasil penelitian menunjukkan bahwa pemborosan tertinggi terjadi adalah defect 2,71% dan waiting 2,29% Pemborosan terjadi akibat rendahnya mutu bahan baku dan seringnya mesin produksi rusak saat proses berlangsung sehingga menambah lead time produksi. Identifikasi VALSAT menggunakan tools terpilih yaitu process activity mapping, overall supply chain effectiveness mapping dan value anaylisis time profile. Rekomendasi yang dilakukan adalah meminimasi waktu current state map dari 1248,83 menit berkurang menjadi 1231,25 menit pada future state map.
Multilevel Image-Enhanced Sentence Representation Net for Natural Language Inference

Natural language inference (NLI) task requires an agent to determine the semantic relation between a premise sentence ( ${p}$ ) and a hypothesis sentence ( ${h}$ ), which demands sufficient understanding about sentences semantic. Due to the issues, such as polysemy, ambiguity, as well as fuzziness of sentences, intense sentence understanding is very challenging. To this end, in this article, we introduce the corresponding image of sentences as reference information for enhancing sentence semantic understanding and representing. Specifically, we first propose an image-enhanced multilevel sentence representation net (IEMLRN), that utilizes the image features from pretrained models for enhancing the sentence semantic understanding at different scales, i.e., lexical-level, phrase-level, and sentence-level. The proposed model advances the performance on NLI tasks by leveraging the pretrained global features of images. However, as these pretrained image features are optimized on specific image classification datasets, they may not show the best performance on NLI tasks. Therefore, we further propose to design an adaptive image feature generator that extracts fine-grained image labels from the corresponding sentences. After that, we extend the IEMLRN to multilevel image-enhanced sentence representation net (MIESR) by utilizing not only the coarse-grained pretrained features of images, but also the fine-grained adaptive features of images. Therefore, sentence semantic can be evaluated and enhanced more comprehensively and precisely. Extensive experiments on two benchmark datasets (SNLI, SICK) clearly show our proposed IEMLRN significantly outperform the state-of-the-art baselines, and our proposed MIESR model achieves the best performance by considering not only the text but also images in an adaptive multigranularities way.
Experimental Studies on the Noise Properties of the Harmonics From a Passively Mode-Locked Er-Doped Fiber Laser

We experimentally investigate the noise properties of a homemade 586 MHz mode-locked laser (MLL). The variation of the timing jitter versus the harmonic order is measured, which is consistent with the theoretical analyses. The dominant contributions to the timing jitter are detailedly studied by analyzing the phase noises at different harmonic frequencies. For low-order harmonics, the intensity noise and relative-intensity-noise-coupled (RIN-coupled) jitter mainly contribute to the timing jitter, while for high-order harmonics, the amplified spontaneous emission (ASE) noise makes the dominant contribution. Then we find that a higher output ratio has an obvious improvement on reducing the timing jitter and suppressing the phase noise because of the shorter pulse duration and lower net cavity dispersion caused by the higher output ratio. Finally a comparison of the noise performance between the MLL and a commercial signal generator is made, which shows that the optically generated radio-frequency signal (OGRFS) has a lower phase noise at high offset frequencies, however the higher phase noise at low offset frequencies leads to a higher timing jitter than the commercial SG.
Identify The Authenticity of Rupiah Currency Using K Nearest Neighbor (K-NN) Algorithm

The rupiah currency is a valid exchange rate used in transactions in the Republic of Indonesia. The Rupiah is often falsified as paper currency. Rupiah paper has a unique texture characteristic so that if processed digitally, it will be easy to distinguish from fake ones. Designing the authenticity of Rupiah currency system using the K-NN method aims to facilitate the authenticity of the currency and test the accuracy of the method used. The method used in this research is the method of Gray Level Co-occurrence Matrix (GLCM) as a method of feature extraction and K-Nearest Neighbor (K-NN) algorithm used in the identification process. The testing phase uses data for 18 currency images. The results showed an accuracy rate of 100% for the value k = 1, 77.78% for the value k = 3, and 55.56% for the value k = 5. The highest level of accuracy in a currency authenticity identification system occurs when the value of k = 1 is 100%. The value of k on the classification input using the K-NN can determine the level of accuracy of the classification process.
Diseño de mecanismos flexibles paralelos basado en teoría de helicoides

Los mecanismos ﬂexibles transmiten movimientos y fuerzas por la deformacion de sus miembros ﬂexibles logrando una cinematica de alta precision. Existen varios metodos para su diseno: metodo de pseudo rigidos, metodo de construccion por bloques, metodo basado en restricciones, metodo FACT (por las siglas en ingles de Freedom, Actuation and Constraint Topologies), optimizacion topologica, entre otros. La aplicacion de la teoria de helicoides en el metodo basado en restricciones es la herramienta adecuada para la sistematizacion del diseno de mecanismos y posibilita su implementacion computacional. En este trabajo se describen los fundamentos del metodo basado en restricciones y se propone utilizar esta herramienta para el diseno de mecanismos ﬂexibles a traves de elementos ﬂexores de viga. Se consideraran pequenos desplazamientos de los mecanismos de forma tal que los ﬂexores siempre trabajen en el campo elastico.
Review of the Performance of Low-Cost Sensors for Air Quality Monitoring

A growing number of companies have started commercializing low-cost sensors (LCS) that are said to be able to monitor air pollution in outdoor air. The benefit of the use of LCS is the increased spatial coverage when monitoring air quality in cities and remote locations. Today, there are hundreds of LCS commercially available on the market with costs ranging from several hundred to several thousand euro. At the same time, the scientific literature currently reports independent evaluation of the performance of LCS against reference measurements for about 110 LCS. These studies report that LCS are unstable and often affected by atmospheric conditions—cross-sensitivities from interfering compounds that may change LCS performance depending on site location. In this work, quantitative data regarding the performance of LCS against reference measurement are presented. This information was gathered from published reports and relevant testing laboratories. Other information was drawn from peer-reviewed journals that tested different types of LCS in research studies. Relevant metrics about the comparison of LCS systems against reference systems highlighted the most cost-effective LCS that could be used to monitor air quality pollutants with a good level of agreement represented by a coefficient of determination R2 > 0.75 and slope close to 1.0. This review highlights the possibility to have versatile LCS able to operate with multiple pollutants and preferably with transparent LCS data treatment.
Spectral Difference Interferometry for the Characterization of Optical Media

A new form of interferometry combining high phase sensitivity and excellent mechanical isolation is proposed and demonstrated. These features arise from maintaining a probe and reference tone in the same medium under test at all times, their ultimate homodyne detection, as well as a novel method employing an optical programmable filter which is used to extract their relative phase difference. A compilation of studies performed to illustrate the applicability of the scheme to a range of measurements of optical propagation characteristics is presented. Measurements include the chromatic dispersion of SMF‐28 of lengths ranging from 1 m to 1 km, the nonlinear coefficient of highly nonlinear fiber and the phase transfer profile of an integrated optical ring resonator.
ISPRS Journal of Photogrammetry and Remote Sensing

Aerosol optical depth (AOD) is a pivotal parameter to reflect aerosol properties, such as aerosol radiative forcing and atmospheric corrections of the aerosol effect. Unfortunately, the valid pixels of moderate resolution imaging spectroradiometer (MODIS) AOD products are scarce, which has attracted great attention from scholars. In recent years, numerous AOD recovering algorithms have been proposed and the algorithms merely employing a single temporal AOD image are regarded as the most convenient and flexible for large-scale practical applications. However, current algorithms face the challenge of insufficiently considering the impacts of aerosol variation resulted from the temporal difference. Meanwhile, the improvement of AOD valid pixels is also poor due to the scarce excavation of complementary information. In order to address these issues, a novel algorithm of spatial-temporal hybrid fusion considering aerosol variation mitigation (ST-AVM) is developed to fill the missing pixels in Aqua AOD products with a single Terra AOD image in large scale. The results show that the total recovered AOD products nearly maintain the original accuracy of MODIS. Meanwhile, the AOD coverage is significantly improved in the study areas and the degrees of improvements regionally vary. Overall, the AOD coverage over land is increased by 123.9% (from 20.5% to 45.9%) after the recovery. Besides, the spatial distribution of recovered monthly AOD products remains fairly consistent as the original Aqua. Also, the recovered annual AOD spatial distribution shows more coherent, which indicates the reliability of ST-AVM algorithm.
Unbiased FIR Filtering for Time-Stamped Discretely Delayed and Missing Data

The unbiased finite impulse response (UFIR) filtering approach is developed for discrete-time state-space models with time-stamped discretely delayed and missing data. The model with <inline-formula><tex-math notation="LaTeX">$k$</tex-math></inline-formula>-step-lags in observations is transformed to have no latency and expanded on a finite horizon of <inline-formula><tex-math notation="LaTeX">$N$</tex-math></inline-formula> most recent data points. It is shown that the optimal horizon for the UFIR filter is practically <inline-formula><tex-math notation="LaTeX">$k$</tex-math></inline-formula>-invariant, unlike the tuning factor of the <inline-formula><tex-math notation="LaTeX">$H_\infty$</tex-math></inline-formula> filter. Higher robustness of the UFIR filter against the Kalman and <inline-formula><tex-math notation="LaTeX">$H_\infty$</tex-math></inline-formula> filters is justified theoretically in uncertain environments with discretely delayed and missing data. Experimental verification is provided based on GPS-based tracking of a moving vehicle to demonstrate a good agreement with the theory.
A wideband circularly polarized slot antenna with antipodal strips for WLAN and C‐band applications

A single‐fed circularly polarized square shaped wide slot antenna with modified ground plane and microstrip feed has been presented. The field in the slot is perturbed by introducing an antipodal strips section attached with a microstrip line to produce circular polarization in a wide band of frequencies. The antipodal strip section consists of a group of four strips of unequal length and separation. The presence of asymmetric perturbations in the slot is mainly responsible for exciting two orthogonal modes in the slot having equal magnitude and 90° phase difference which results in circular polarization. A wide bandwidth of 3.3 GHz (4.4 GHz‐7.7 GHz) has been achieved for an axial ratio value AR < 3 dB with the minimum axial ratio value being 0.3 dB. The impedance bandwidth for |S11| < −10 dB ranges from 4.3 GHz to 8 GHz, and therefore covers most of the C‐band communication systems. The antenna exhibits stable radiation patterns throughout the circular polarization bandwidth with a gain around 6 dBi in entire operational bandwidth. A prototype of antenna was fabricated and measured. The antenna has a planar size 0. 40λ0 × 0. 40λ0 and thickness of 0. 02λ0 where λ0 is the wavelength in free space at the lowest frequency. With its compact size and low profile, the antenna is a favorable choice for WLAN (5.15‐5.85 GHz) and a wide variety of C‐band wireless applications.
Crystallisation in Melts of Short, Semi-Flexible Hard-Sphere Polymer Chains: The Role of the Non-Bonded Interaction Range

A melt of short semi-flexible polymers with hard-sphere-type non-bonded interaction undergoes a first-order crystallisation transition at lower density than a melt of hard-sphere monomers or a flexible hard-sphere chain. In contrast to the flexible hard-sphere chains, the semi-flexible ones have an intrinsic stiffness energy scale, which determines the natural temperature scale of the system. In this paper, we investigate the effect of weak additional non-bonded interaction on the phase transition temperature. We study the system using the stochastic approximation Monte Carlo (SAMC) method to estimate the micro-canonical entropy of the system. Since the density of states in the purely hard-sphere non-bonded interaction case already covers 5600 orders of magnitude, we consider the effect of weak interactions as a perturbation. In this case, the system undergoes the same ordering transition with a temperature shift non-uniformly depending on the additional interaction. Short-range attractions impede ordering of the melt of semi-flexible polymers and decrease the transition temperature, whereas relatively long-range attractions assist ordering and shift the transition temperature to higher values, whereas weak repulsive interactions demonstrate an opposite effect on the transition temperature.
A Compact Broadband Circularly Polarized Crossed-Dipole Antenna With a Very Low Profile

A low-profile wideband circularly polarized (CP) crossed-dipole antenna with eight parasitic elements is presented. The parasitic elements are located on the top and bottom surfaces of the same substrate printing the crossed dipoles, and each consists of a horizontal patch and a vertical shorting pin. It has been found that the introduction of the four parasitic shorted patches on the bottom surface of the substrate can enhance the bandwidth and reduce the profile of the antenna, while the four parasitic shorted patches on the top surface of the substrate can further increase the axial-ratio (AR) bandwidth and improve the boresight gain, leading to a low-profile wideband CP antenna with stable in-band gain. For validation, a prototype was fabricated and measured. The measured results demonstrate that the proposed antenna has a profile of as low as 0.067 λ0, a −10 dB impedance bandwidth of 61.8%, a 3 dB AR bandwidth of 51.6%, and a gain fluctuation of 1.2 dB within the overlapping passband.