Miracle-dz/UniFAR-FTUs huggingface dataset:
Camera calibration method with checkerboard pattern under complicated illumination

Abstract. Camera calibration is a key step in three-dimensional (3-D) reconstruction; however, the calibration accuracy and stability often suffer from complicated illumination in real applications. The camera calibration method using the checkerboard pattern is improved for high-precision calibration under complicated illumination. First, an improved Harris corner detector based on color constancy, as well as a subpixel optimization method based on prior knowledge of the checkerboard, are proposed to overcome the influence of bad lighting. Second, a checkerboard pattern with a central circle point is designed for better reference point location for uneven illumination. The checkerboard identification by Delaunay triangulation is also improved for the situation of discontinuity caused by over-saturation. Finally, the camera parameter optimization process is improved to reduce the calibration error produced by complicated illumination. Experimental results show that the improvements achieve more accurate and stable calibration results in complicated lighting conditions compared with traditional methods.
Efficient Multi-UAS Coverage Over Complex Domains

The paper presents an application of Spectral Multiscale Coverage (SMC) for multi-vehicle coverage and search in complex environments. The SMC approach gives rise to multiscale vehicle trajectories leading to efficient and robust coverage which could be valuable in a variety of applications. In order to handle environments with complex search regions and highly non uniform priority map, a non convex polygonal approximation is utilized. A detailed study of the impact of vehicle dynamics and priority map resolution is conducted in the context of several complex coverage problems involving road network, and mountainous terrain.
Integrated cosparse analysis model with explicit edge inconsistency measurement for guided depth map upsampling

Abstract. A low-resolution depth map can be upsampled through the guidance from the registered high-resolution color image. This type of method is so-called guided depth map upsampling. Among the existing methods based on Markov random field (MRF), either data-driven or model-based prior is adopted to construct the regularization term. The data-driven prior can implicitly reveal the relation between color-depth image pair by training on external data. The model-based prior provides the anisotropic smoothness constraint guided by high-resolution color image. These types of priors can complement each other to solve the ambiguity in guided depth map upsampling. An MRF-based approach is proposed that takes both of them into account to regularize the depth map. Based on analysis sparse coding, the data-driven prior is defined by joint cosparsity on the vectors transformed from color-depth patches using the pair of learned operators. It is based on the assumption that the cosupports of such bimodal image structures computed by the operators are aligned. The edge inconsistency measurement is explicitly calculated, which is embedded into the model-based prior. It can significantly mitigate texture-copying artifacts. The experimental results on Middlebury datasets demonstrate the validity of the proposed method that outperforms seven state-of-the-art approaches.
Low-Coherence Interferometry Using Microwave Photonics for Multilayered Samples

A photonic structure is proposed by exploiting the advantages of the Microwave Photonics technology over conventional low coherence interferometry. The proposed scheme is based in the analysis of the interference pattern of an incoherent optical signal which is amplitude modulated and transmitted through a dispersive element. The strategic allocation of an interferometric structure combined with balanced photodetection are used to improve the system performance compared to the previous proposals. To the best of our knowledge, an exhaustive theoretical analysis and an experimental demonstration of the structure for multilayered samples are provided in this paper.
Calculation Method Study of HTS Coils’ Critical Current

A method to calculate second-generation (2G) high temperature superconducting (HTS) coils’ critical current is presented. Critical current and n value of HTS tapes measured under different magnet field are used for the calculation of the coil. The distribution of HTS coils’ magnetic field intensity, current density, and electric field intensity is calculated with COMSOL 2-D based on H formulation. A partial differential equation (PDE) model and the magnetic field formulation (mfh) model of HTS tape are constructed. The modeling method and key points are also introduced and discussed. AC loss of the HTS tape is calculated with the above-mentioned two models, respectively. The calculation results of the two modeling approaches are coincident. The cross sections of the straight segment and bending segment of a HTS racetrack double-pancake coil are modeled, respectively, with a 2-D and 2-D-axisymmetric model in COMSOL, and the critical current is calculated. E–I properties of each turn of the coil and the critical current are calculated. HTS coils with seven pairs of voltage lead are wound. Voltages at different parts of the coils and the critical current are measured. The measurement results of the magnetic field, electric field, and critical current agree with the calculation results. The method presented in this paper can also be referred to when designing an HTS machine with HTS tapes or coils.
Dynamic Surface Control for Multirotor Vehicles

In this paper we present the design of Dynamic Surface Control (DSC) law for multirotor vehicles. We first propose a mathematical model which can be used for a wide class of multirotor vehicles. Then, we extend the classical DSC such that it can be applied to the proposed model for tracking pitch, roll, yaw and altitude. The DSC performances are compared with other nonlinear algorithms known in the literature, namely backstepping and sliding mode, as well as PID controller, where all the control laws were tuned via the same heuristic random search algorithm in order to ensure a fair comparison.
Study of 130 nm SiGe HBT Periphery in the Design of 160 GHz Power Amplifier

At mm wave, and sub-THz frequencies the foundry usually does not provide information about the power amplifying capability or optimum impedances of the transistors for maximum power, and efficiency. Therefore, in this paper, we studied and analyzed the size of a SiGe HBT (Heterojunction Bipolar Transistor) in terms of output power and efficiency performance for the design of a power amplifier (PA) operating at 160 GHz. Load pull simulations were performed for various size of transistors. Optimum size transistors resulting in high power and efficiency are used to design a 160 GHz power amplifier using the foundry models for transmission lines and MIM capacitors. The simulated power amplifier (excluding interconnects for transistors and MIM) achieves a simulated output power of 18 dBm with a power added efficiency (PAE) of 19%. Future work includes the design of low loss interconnects for transistors and MIM capacitors, and fabrication of the power amplifier.
Generic dynamic modeling for multirotor VTOL UAVs and robust Sliding Mode based Model-Free Control for 3D navigation

This paper introduces a generic and accurate dynamic model, based on Newton-Euler formalism, for multirotor vehicles taking into consideration aerodynamic effects. Besides, the paper considers a reformulation of the well-known Model-Free Control (MFC), which is applied for a low-cost quadrotor even in the presence of various type disturbances, including unmodeled or neglected dynamics, parametric uncertainties, external disturbances, etc. This reformulation takes into consideration the limitation of the estimator used by the classical MFC by using a Sliding Mode auxiliary Controller (SMC) leading to SMC-MFC controller. In addition, instead of using a pure data-driven based control, we introduce the available mathematical dynamics of the system even if they are poorly known. Herein, the MFC principle is employed to deal with the unknown part of the plant only (i.e., unmodeled dynamics, disturbances, etc.). The stability of the closed-loop system is guaranteed and for which a theoretical analysis is provided. The numerical simulations have shown satisfactory results. An in-depth discussion, with respect to the control performance and consumed energy, is highlighted by considering several scenarios and using several metrics.
Analysis of Supervised and Unsupervised Learning in Content Based Multimedia Retrieval

This work analyze images using different learning algorithms such as supervised and unsupervised algorithm for image retrieval. The color and shape based image descriptors are used to distinguish specific set of images from the whole database. Wang's database is taken to extract the ten clustered color and shape features such as ten-dominant color descriptor and Zernike Moments from the image. The supervised learning algorithms named as Support Vector Machine (SVM) K-Nearest Neighbour (KNN), Naive-Bayes and Random Forest are trained by this feature vectors are used for class prediction. Subsequently, highest probability class images are grouped to reduce the search space for similar images. The distance measure is used to calculate the similarity between the user query and newly grouped images.
Quantitative and qualitative composition of yeast microbiota in spontaneously fermented grape musts obtained from cool climate grape varieties ‘Rondo’ and ‘Regent’

The aim of the study was to characterise, quantitatively and qualitatively, the yeast microbiota found during spontaneous fermentation of grape musts obtained from the red grape varieties 'Rondo' and 'Regent'. For the research, grapes originating from two vineyards (Srebrna Góra and Spotkaniówka) located in southern Poland were used. Musts of the studied grape varieties provided a favourable environment for the growth of microorganisms. Musts obtained from fruits from the Spotkaniówka vineyard were characterised by a higher overall number of yeasts. A maximum number of cells were recorded from the fourth to the ninth day of the process, in all of the analysed musts. The growing season of 2013 proved to be the least favourable for the growth of microorganisms on grapes, which resulted in their smaller number in the batches during spontaneous fermentation. During the process, succession of different groups of yeasts was observed. It was initiated by Hanseniaspora uvarum and Candida railenensis strains, which, with the progress of spontaneous fermentation, were replaced by Saccharomyces cerevisiae strains. Metschnikowia pulcherrima and Pichia membranifaciens yeasts were identified at both the beginning and the end of the process. During fermentation, Zygoascus meyerae, Kluyveromyces lactis and Nakazawaea ishiwadae strains were also identified.
Provenance Across Evidence Combination in Theory of Belief Functions

Theory of belief functions (Dempster-Shafer theory) is one of the most commonly used mathematical frameworks in the field of uncertain information representation. Two important areas of research in its context are that of evidence combination and decision making. Although they are often considered theoretically separate, the combination process itself drives the final decision. The information contained in each of the sources propagates through the belief aggregation process, and impacts the final assessment to some degree. If the decision made has an impact on the real-world; particularly in scenarios where a wrong decision may bring about significant risks it is prudent to be able to identify the key drivers of this assessment. In this paper we present a novel method of identifying the relative contribution of each source of evidence to the final belief, thus making it possible to track provenance across the information fusion process. This is likely to be useful in intelligent decision-support systems utilising belief functions, where lack of transparency may be hindering adoption. Unlike traditional methods, which focus on the content of the contributing source only, the approach proposed here is based on analysis of dissimilarity between the contributing sources; the result of the fusion process and the decision made. The behaviour of this metric is analysed through simulation. It is shown that the proposed measure performs well with regard to identifying the source having the most significant impact on the decision, often outperforming more traditional metrics.
Towards Printing Mechatronics: Considerations for 3D-printed conductive coupling

This paper has investigated the integration of 3D-printed conductive paths into 3D-printed non-conductive structures, with the goal of exclusively combining standard off-the-shelf components with additive manufactured pieces in order to build a mechatronic device. To this end, a chosen conductive material has initially been mechanically and electrically characterized through measuring the elasticity by dynamic mechanical analysis, and performing tests on conductivity with respect to influencing parameters such as contact pressure and macroscopic time-dependent effects. This has been further correlated with deflection calculations used for designing a conductive coupling which integrates a conventional DC motor into a 3D-printed holder. The housing has then been manufactured and operational testing of the assembly was performed. Considerations concerning the manufacturing process of a 3D-printed mechatronic assembly have been presented, along with potential further applications relying on the obtained results.
Time-Domain Characterization of Digitized PWM Inverter With Dead-Time Effect

This paper presents an analytical solution to characterize harmonic behavior of digitally controlled H-bridge inverter output with two nonlinear effects: sample delay and dead-time. The effect of sampling frequency in uniformly sampled pulse-width modulation (PWM) is discussed, including spectral analysis and compared with the analog modulated PWM. The effect of dead-time on the rising and falling edge of digitized PWM inverter error output is derived in time-domain. The double Fourier integral solution is used to develop the accurate mathematical expressions for the switched output waveforms. The integral solutions are obtained using Jacobi–Anger expansions. The analytical results are verified with simulation using PSCAD and experimental results.
Rule-Based Model for Smart Building Supervision and Management

Smart buildings are aimed at monitoring and controlling building facilities through a Building Management System (BMS). While current BMSs are based on processing logs of devices deployed in the building, this paper enables supervision and control of building by the use of semantic technologies. A common information base, as a core data model, is defined, which describes and defines formally the main physical and conceptual building elements (namely: assets, spaces, data points, incidents and key performance indicators), their characteristics and interrelationships, as well as the constraints that apply to them. For instantiation purposes, we relied on a logical framework based on the existential rules, which allows to describe any domain as a set of facts, a set of rules and a set of constraints. We have implemented a fragment of our logical model as a proof of concept, where two real-world scenarios are implemented as demonstrators of the FUSE-IT project. The former is about access control to a data center, and the latter is about temperature anomaly correlated with the heater functioning in a given zone of a building. The aim of these experiments is to illustrate the functional capabilities of our approach for smart control in building management.
Investigating equalisation of health inequalities during adolescence in four low-income and middle-income countries: an analysis of the Young Lives cohort study

Objective To investigate if socioeconomic gradients in health reduce during adolescence (the equalisation hypothesis) in four low-income and middle-income countries (LMIC). Setting Analysis of the Young Lives Study cohorts in Ethiopia, Peru, Vietnam and India. Participants A total of 3395 participants (across the four cohorts) aged 6–10 years at enrolment and followed up for 11 years. Outcomes measured Change in income-related health inequalities from mid-childhood to late adolescence. Socioeconomic status was determined by wealth index quartile. The health indicators included were self-reported health, injuries in the previous 4 years, presence of long-term health problems, low mood, alcohol use, overweight/obesity, thinness and stunting. The relative risk of each adverse health outcome between highest and lowest wealth index quartile were compared across four waves of the study within each country. Results We found steep socioeconomic gradients across multiple health indicators in all four countries. Socioeconomic gradients remained similar across all waves of the study, with no significant decrease during adolescence. Conclusion We found no consistent evidence of equalisation for income-related health inequalities in youth in these LMIC. Socioeconomic gradients for health in these cohorts appear to persist and be equally damaging across the early life course and during adolescence.
An Ontological Sub-Matrix Factorization based Approach for Cold-Start Issue in Recommender Systems

With the rapidly growing usage of e-commerce applications, it is becoming more and more tedious for the vendors to perform accurate and relevant recommendations to the users visiting their websites, especially first time. This is a type of cold start problem in the recommender systems. In this paper, an ontological sub-matrix factorization based approach is suggested for recommending items to a new user. The main contribution of the paper is that, for recommending any items to a new user, no personal information regarding user is captured or extracted, thereby respecting the privacy of the user. The proposed approach when tested has shown an accuracy of 98 percent in terms of recall value.
A Temporal and Spatial Constrained Attribute-Based Access Control Scheme for Cloud Storage

Cloud storage service allows data owners to store their (encrypted) data in a remote and may be untrusted cloud server. Attribute-Based Encryption (ABE) provides an excellent and flexible solution for data access control. As more and more applications evolved, ABE schemes may not handle all scenarios, in particular, if the access control has a time and location constraint. Time and location attributes are not as static as other general attributes. Existing ABE schemes cannot efficiently handle the continuous range of an attribute making it impractical for temporal and spatial constraints that are changing dynamically. In this paper, we propose a novel temporal and spatial constrained attribute-based access control (TSC-ABAC) scheme to solve this problem. Our system adopts a redesigned access structure and makes use of multi-dimensional range derivation function to match the time domain. This is the first ABE scheme that can efficiently handle time and location elements simultaneously. We further propose an extended TSC-ABAC scheme, which aims at reducing the decryption cost imposed on user. A thorough security and performance analysis shows that our design is secure and efficient. The result of our work could provide a feasible and practical data access control scheme for cloud storage services.
A Cavity-Backed Endfire Dipole Antenna Array Using Substrate-Integrated Suspended Line Technology for 24 GHz Band Applications

This paper presents a $1\times4$ cavity-backed endfire dipole antenna array based on substrate-integrated suspended line (SISL) platform. A double-side SISL (DSISL) self-packaged feeding network with irregular boundaries is designed for the array. By utilizing the DSISL feeding network, the radiation loss and substrate loss of the feed line are effectively decreased, thus efficiency of better than 91% is achieved. Instead of the conventional metallic cavity, the proposed cavity structure is realized by multiple substrate layers. A predominantly TE10 aperture field is obtained by adjusting the sizes of the backing cavity. Measured results show that the proposed dipole antenna array has narrow beam widths in the E-plane and obtained 10 dB impedance bandwidth of 19.7%, i.e., from 22.77 to 27.75 GHz which can cover the 24 GHz automotive radar band (24.25–26.65 GHz). Moreover, front-to-back ratio of better than 26 dB, high gain of better than 14.1 dBi, and low sidelobe level of better than −15 dB are achieved over the automotive radar frequency band.
Compact Chebyshev Differential-Mode Bandpass Filter on  $\lambda$ /4 CPS Resonator With Intrinsic Common-Mode Rejection

In this paper, a new class of compact Chebyshev differential-mode (DM) bandpass filters with intrinsic common-mode (CM) rejection is proposed and demonstrated on <inline-formula> <tex-math notation="LaTeX">$\lambda$ </tex-math></inline-formula>/4 coplanar stripline (CPS) resonators with an improved unloaded quality factor (<inline-formula> <tex-math notation="LaTeX">$Q_{u}$ </tex-math></inline-formula>). The distinct advantage of the proposed <inline-formula> <tex-math notation="LaTeX">$\lambda$ </tex-math></inline-formula>/4 CPS resonator with higher <inline-formula> <tex-math notation="LaTeX">$Q_{u}$ </tex-math></inline-formula> than slotline resonator, together with intrinsic CM rejection of CPS line, can demonstrate that <inline-formula> <tex-math notation="LaTeX">$\lambda$ </tex-math></inline-formula>/4 CPS resonator is more suitable for the design of narrowband DM filter than others on slotline resonator. Then, the underlying physics why CPS resonator possesses higher <inline-formula> <tex-math notation="LaTeX">$Q_{u}$ </tex-math></inline-formula> than slotline resonator is numerically studied and further interpreted by the radiation loss. To facilitate the design process, an analytical design approach is introduced by using alternative J/K inverters and a tailored method is used to extract J/K inverter values with their associated effective electrical lengths based on their equivalent circuit models. Finally, two design examples, a second-order and a fourth-order DM Chebyshev bandpass filter, are designed and implemented, operating at the center frequency of 1.8 GHz with the fractional bandwidths of 6% and 19%, respectively. The simulated and measured DM/CM frequency responses match well with each other. The proposed DM filters based on <inline-formula> <tex-math notation="LaTeX">$\lambda$ </tex-math></inline-formula>/4 CPS resonators have demonstrated the claimed superior performances in terms of intrinsic CM rejection, improved unloaded quality factor, easy implementation of J/K inverter, inherent suppression of first DM harmonic, and compact size.
Matrix metalloprotease 3 is associated with sarcopenia in rheumatoid arthritis ‐ results from the CHIKARA study

Patients with rheumatoid arthritis (RA) show lower muscle mass and a higher prevalence of sarcopenia than healthy individuals. Correlations between sarcopenia and disease activity, physical function, laboratory data and body composition at baseline were investigated in a prospective, observational study (CHIKARA study) of RA patients.