Miracle-dz/UniFAR-FTUs huggingface dataset:
Natural Oscillation Gait in Humanoid Biped Locomotion

Biped locomotion is complex to analyze in general. Most of the models in the literature for biped locomotion utilize hybrid dynamics. This makes the kinematics of the model simple to understand. However, it makes the model difficult to analyze in the presence of discontinuous terms in its differential equations. This article presents a continuous-time mathematical model for biped robots, modeling the discontinuities in impact with a nonlinear function. Natural oscillation is defined as a free response under damping compensation to achieve persistent oscillation. The phenomenon of natural oscillation was previously exploited in the linear dynamics of multi-segmental locomotor, and it is now extended to this continuous-time biped locomotion model with the contact force from the ground modeled as a nonlinear bump function. The idea of natural oscillation is preceded in this article by a complete framework on analysis and entrainment control. The research would ensure that these natural oscillations are responsible for forward locomotion of biped robots under certain conditions. The locomotion profile of the bipeds further validates the model that the velocity achieved through the natural oscillation is comparable to human jogging speeds when practical constraints are enforced.
Presenting New Framework For Semi-automatic Composition Of Web Services

Many recent studies regarding web focused on the web services composition. The main advantage of the web services over other distributed systems technologies is the possibility of automatic services composition with previous ones so it is possible to do a series of recommended operations. Many techniques have been presented to realize the idea, but it is still challengeable how to compose such services to be both sufficient and realizable structurally. In the study we present some techniques to be used to facilitate the discovery, choice and semi-automatic composition of incongruous web services. The framework has three main qualities distinct from other activities in the same field; first the algorithm makes possible the discovery and the composition of present services according to the user's needs in low error possibility. Meanwhile, it differentiates between different levels of workflows and finally the proposed framework permits the user to distinguish and scrutinize the workflow with high authority.
Multiscale Approximate Entropy for Gait Analysis in Patients with Neurodegenerative Diseases

Neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Parkinson’s diseases (PD), and Huntington’s disease (HD) are not rare neurological diseases. They affect different neurological systems and present various characteristic gait abnormalities. We retrieved gait signals of the right and left feet from a public domain on the Physionet. There were 13 patients with ALS, 15 patients with PD, 20 patients with HD and 16 healthy controls (HC). We used multiscale approximate entropy (MAE) to analyze ground reaction force on both feet. Our study shows that MAE increases with scales in all tested subjects. The group HD has the highest MAE and group ALS has the lowest MAE. We can differentiate ALS from HC by MAE, while scale factors >10 in the left foot. There are few significant differences of MAE between the HC and HD. We found a good correlation of MAE between both feet in group ALS. In conclusion, our results indicate that MAE analysis of gait signals can be used for diagnosis and long-term assessment for ALS and probably HD. Similarity of MAE between both feet can also be a diagnostic marker for ALS.
Measurement of Van der Waals force using oscillating optical tweezers

We employ oscillating optical tweezers as a probe to measure the surface forces between polystyrene and silica. Thus, we modulate a trapped polystyrene particle with an external sinusoidal force in close proximity (∼80 nm) of a silica surface. The particle motion is influenced by several factors which include an increased drag force according to Faxen's correction, a spurious force that comes into play due to the diffusion coefficient of the medium becoming position dependent, and finally, the London-Van der Waals (LVdW) force which becomes substantial when the particle approaches the surface. By accounting for the other forces from the analytically known results, we are able to directly quantify the LVdW force from the experimentally measured amplitude of the oscillating particle. Thereby, we determine the Hamaker constant H for the LVdW force between polystyrene and silica, and obtain a good agreement with the value reported in the literature. Our method is general in nature and can be extended toward probing other surface effects or other interaction forces using oscillating optical tweezers.We employ oscillating optical tweezers as a probe to measure the surface forces between polystyrene and silica. Thus, we modulate a trapped polystyrene particle with an external sinusoidal force in close proximity (∼80 nm) of a silica surface. The particle motion is influenced by several factors which include an increased drag force according to Faxen's correction, a spurious force that comes into play due to the diffusion coefficient of the medium becoming position dependent, and finally, the London-Van der Waals (LVdW) force which becomes substantial when the particle approaches the surface. By accounting for the other forces from the analytically known results, we are able to directly quantify the LVdW force from the experimentally measured amplitude of the oscillating particle. Thereby, we determine the Hamaker constant H for the LVdW force between polystyrene and silica, and obtain a good agreement with the value reported in the literature. Our method is general in nature and can be extended toward p.
Development of a Misaligned Tropical Cyclone

A cloud-resolving model is used to examine the virtually shear-free evolution of incipient tropical cyclones initialized with different degrees of misalignment between the lower- and middle-tropospheric centers of rotation. Increasing the initial displacement of rotational centers (the tilt) from a negligible value to several hundred kilometers extends the time scale of hurricane formation from 1 to 10 days. Hindered amplification of the maximum tangential velocity υm at the surface of a strongly perturbed system is related to an extended duration of misalignment resulting from incomplete early decay and subsequent transient growth of the tilt magnitude. The prolonged misalignment coincides with a prolonged period of asymmetric convection peaked far from the surface center of the vortex. A Sawyer–Eliassen model is used to analyze the disparity between azimuthal velocity tendencies of selected pre–tropical storm vortices with low and high degrees of misalignment. Although no single factor completely explains the difference of intensification rates, greater misalignment is linked to weaker positive azimuthal velocity forcing near υm by the component of the mean secondary circulation attributed to heating by microphysical cloud processes. Of note regarding the dynamics, enhanced tilt only modestly affects the growth rate of kinetic energy outside the core of the surface vortex while severely hindering intensification of υm within the core for at least several days. The processes controlling the evolution of the misalignment associated with inefficient development are examined in detail for a selected simulation. It is found that adiabatic mechanisms are capable of driving the transient amplification of tilt, whereas diabatic processes are essential to ultimate alignment of the tropical cyclone.
Information scan of quantum states based on entropy-power uncertainty relations

We use Rényi-entropy-power-based uncertainty relations to show how the information probability distribution associated with a quantum state can be reconstructed in a process that is analogous to quantum-state tomography. We illustrate our point with the so-called “cat states”, which are of both fundamental interest and practical use in schemes such as quantum metrology, but are not well described by standard variance-based approaches.
Modelagem de Pára-Raios de ZnO para o cálculo de tensão induzida por descarga atmosférica em redes de distribuição

Atualmente, a competitividade do mercado energetico e a atuacao dos orgaos reguladores exigem das concessionarias de energia um fornecimento extremamente conavel e que atenda aos limites estabelecidos para os diversos indicadores de qualidade (variacoesde tensao de curta duracao, desequilibrio de tensao, harmonicos, tensao em regime permanente, etc.). Assim, a ecacia da protecao do sistema contra sobretensoes e fundamental para qualquer concessionaria que objetive fornecer ao consumidor uma energia dentrodos padroes determinados. Conforme ja mostrado por diversos estudos, a sobretensao provocada por descarga atmosferica e o principal causador de problemas nas redes de distribuicao. Nos sistemas modernos, a utilizacao adicional de para-raios de oxido de zinco (ZnO) tem sido uma boa solucao para limitar esses disturbios, evitando a interrupcao da operacao, tanto em linhas de distribuicao quanto nas linhas de transmissao. Neste trabalho foi desenvolvida uma ferramenta de calculo de tensao induzida por descargas atmosfericas indiretas em linhas de distribuicao com protetores de ZnO, segundoa teoria de Rusck implementada em programas de calculo de transitorios eletromagneticos (metodo Rusck-EMTP). A rotina implementada permite a estimativa da tensao induzida em sistemas polifasicos com grande quantidade de estruturas e de para-raios de ZnO, representados por sua curva V xI. Para validar os resultados da metodologia implementada, foram realizados testes de calculo da tensao induzida em uma linha de distribuicao, trifasica, variando-se o ponto de incidencia da descarga indireta, a quantidade e o posicionamento dos dissipadores surto. Os resultados mostraram que o programa desenvolvido fornece uma boa estimativa para tensoes induzidas em sistemas de distribuicao complexos com para-raios de oxido metalico. Amplia-se dessa forma, a grande potencialidade dos softwares do tipo EMTP.
Start-Up and Saturation Optimization of High-Power Energy Harvester With Compound Topologies Overhead AC Transmission Line

With the continuous development of power automation and smart grids, online monitoring equipment has been utilized more widely for inspection of the state of high-voltage ac transmission lines. To ensure the stable and effective work of the monitoring device, the problem of power supply needs to be solved urgently. Although the inductive energy harvester penetrated through line has been extensively researched, the practical process has been greatly hindered caused by the core materials, which cannot simultaneously combine two advantages of both high permeability and high saturation. Based on the inherent contradiction of the inductive energy harvester, the structure of compound cores with different intrinsic properties is adopted. In addition, three optimization topologies for the structure are proposed. Theoretical analysis and experimental results show that the proposed structures and topologies have certain advantages over the conventional structure in terms of effective start-up sensitivity, saturation performance, and gained power. The proposed energy harvesters also broaden the effective working range by enduring the primary current fluctuation. The simulation and experimental results verify the correctness of the theoretical analysis and the validity of the topologies.
Mismatch Loss in Bifacial Modules Due to Nonuniform Illumination in 1-D Tracking Systems

We apply ray tracing to compute the light-generated current <italic>I<sub>L</sub></italic> within each solar cell of a bifacial tracking module, and circuit modeling to quantify how the spatial variability in <inline-formula><tex-math notation="LaTeX">$I_{L}$</tex-math></inline-formula> (i.e., current mismatch) reduces the module's output power <italic>P</italic><sub>MP</sub>. We find that 10 million rays are required to accurately map <inline-formula><tex-math notation="LaTeX">$I_{L}$</tex-math></inline-formula> for a central module in a photovoltaic (PV) system at a given insolation condition. The relative reduction in <italic>P</italic><sub>MP</sub> is found to be 1) greatest in the middle of the day for sunny conditions, 2) independent of time for very cloudy conditions, 3) higher for edge modules than central modules, 4) higher for one-high portrait configurations than for two-high, and 5) higher when the ground albedo is higher. We trace 2 billion rays on 2000 parallel cores to solve a module's annual energy yield for a system located at Golden CO with a sandy soil. The yield reduction in a one-high configuration due to nonuniform illumination is 0.23% for a central module and 0.35% for an edge module. Thus, in this example, mismatch loss due to nonuniform illumination within an individual tracking module is relatively low, despite the rear of the module being shaded by a torque tube.
A simple, dynamic extension of temporal motivation theory

ABSTRACT Temporal motivation theory (TMT) has been criticized for its static representation and neglect of the environment. In this paper, I develop goal sampling theory (GST) to appease these criticisms and extend our understanding of goal choices beyond momentary preferences and into dynamic updating and sampling behavior across time. GST draws from temporal motivational theory, sampling models of impression formation, and organizational theory on how the environment constrains behavior and situates aspects of each into a formal model of goal sampling. Doing so addresses the limitations of our prior thinking, introduces new concepts and predictions, and provides a mathematical framework that lends itself to computational modeling.
Climate Change Influences of Temporal and Spatial Drought Variation in the Andean High Mountain Basin

Climate change threatens the hydrological equilibrium with severe consequences for living beings. In that respect, considerable differences in drought features are expected, especially for mountain-Andean regions, which seem to be prone to climate change. Therefore, an urgent need for evaluation of such climate conditions arises; especially the effects at catchment scales, due to its implications over the hydrological services. However, to study future climate impacts at the catchment scale, the use of dynamically downscaled data in developing countries is a luxury due to the computational constraints. This study performed spatiotemporal future long-term projections of droughts in the upper part of the Paute River basin, located in the southern Andes of Ecuador. Using 10 km dynamically downscaled data from four global climate models, the standardized precipitation and evapotranspiration index (SPEI) index was used for drought characterization in the base period (1981–2005) and future period (2011–2070) for RCP 4.5 and RCP 8.5 of CMIP5 project. Fitting a generalized-extreme-value (GEV) distribution, the change ratio of the magnitude, duration, and severity between the future and present was evaluated for return periods 10, 50, and 100 years. The results show that magnitude and duration dramatically decrease in the near future for the climate scenarios under analysis; these features presented a declining effect from the near to the far future. Additionally, the severity shows a general increment with respect to the base period, which is intensified with longer return periods; however, the severity shows a decrement for specific areas in the far future of RCP 4.5 and near future of RCP 8.5. This research adds knowledge to the evaluation of droughts in complex terrain in tropical regions, where the representation of convection is the main limitation of global climate models (GCMs). The results provide useful information for decision-makers supporting mitigating measures in future decades.
A 3-D Trailer Approach to Leader-Following Formation Control

A real-time 3-D trajectory planner for the leader-following formation control of autonomous vehicles is proposed. The planner relies on the definition of a trailer body whose hinge point is rigidly attached to the leader and assigns each follower to a distinct point of such a trailer. Convergence results for the trailer body reference frame are presented based on Lyapunov analysis, which guarantee that the planning can be independently implemented by <inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> followers, with a common leader, as they asymptotically behave as <inline-formula> <tex-math notation="LaTeX">$n$ </tex-math></inline-formula> points of a unique trailer body. As such, the need for communication among followers is dispensable. The proposed strategy is divided into trajectory planning and trajectory tracking, the first problem being vehicle-independent. Experimental results obtained with quadrotor vehicles are presented, which demonstrate the richness and suitability of the planned trajectories.
Three dimensional nonlinear simulation, sensitivity analysis and increasing the maximum frequency to 2.5 Hz using a physics-based method for basins in Ottawa, Canada

We performed 3-D nonlinear-viscoelastic ground motion simulations using a finite difference modeling method in a frequency range of 0.1 to 1 Hz in the Kinburn basin, Ottawa, Canada, for large earthquakes. Comparing the records and simulated velocity time series showed that regular viscoelastic simulations could model the ground motions at the rock and soil sites in the Kinburn basin for the Ladysmith earthquake (Mw=4.7). Using nonlinear-viscoelastic ground motion simulations for the scaled Ladysmith earthquake (Mw=7.5) significantly reduced the amplitude of the horizontal components of the Fourier spectrum and the predicted PGA and PGV values compared to regular linear viscoelastic simulations. Further, using a finite fault source (Mw=7) for the nonlinear-viscoelastic simulation decreased PGAs of the horizontal components. Our sensitivity analysis of simulations for different seismic moments showed that the PGV values exponentially increased with moment magnitude. Using a Gaussian source function with a short half duration increased the PGVs and the amplitude of velocity Fourier spectrum. Relaxation times and relaxation coefficients for viscoelastic simulation significantly increased PGV, the amplitude of the PSA ratio, and the velocity Fourier spectrum for a small earthquake. Employing a small soil Q model reduced PGV, PSA of soil/rock ratios, and the amplitude of velocity Fourier spectrum. Using finite fault model for a large earthquake (Mw =7) significantly reduced the PGV values relative to a point source model. We increased the maximum frequency to 2.5 Hz in FD modeling using a dual grid size method for two basins (Kinburn and Orleans basins in Ottawa, Canada). The simulated velocity time series from the dual grid size method provided better results compared to the results of the single grid size, although there were large differences between the amplitude of the velocity Fourier spectrum of the simulations and the amplitude of the records, particularly at low frequencies (<1 Hz). However, the velocity Fourier spectrums of the records and simulations showed a similar variation versus frequency. Further, using the dual grid size method increased the PGVs and amplitudes of the velocity Fourier spectrum for both the Kinburn and Orleans basins compared to the results of the single grid size simulation.
Autonomous Indoor Exploration Via Polygon Map Construction and Graph-Based SLAM Using Directional Endpoint Features

In this paper, a novel 2-D laser-based autonomous exploration approach for mobile robots is proposed, which is based on a novel polygon map construction approach and graph-based simultaneous localization and mapping (SLAM) with directional endpoint features. This approach is composed of three modules: graph-based SLAM using directional endpoint features, polygon map construction, and exploration. Different from existing approaches in the field of 2-D SLAM, the newly proposed 2-D graph-SLAM is based on 3-D “directional endpoint” features; on this basis, a well-known data structure “circular-doubly linked list” is applied to construct a novel polygon map for navigation. Note that it is efficient for circular-doubly linked list to initialize and update the polygon map. In addition, we propose a new information entropy calculation approach to quantify the entropy of the polygon map. Then for each candidate goal, we could obtain corresponding information gain and make next decision through collision detection. Comparative experimental results with respect to the well-known Gmapping and Karto SLAM are presented to show superior performance of the proposed graph-based SLAM. The autonomous exploration experiments in the office and hallway environments show the effectiveness of the proposed approach for robotic mapping and exploration tasks. Note to Practitioners—This paper is motivated by the challenges of autonomous exploration for mobile robots. We suggest a novel autonomous exploration approach through directional endpoint feature-based graph simultaneous localization and mapping (SLAM) and polygon map construction. This newly proposed approach does not require any artificial landmark or underlying occupancy grid map, which is easy to implement. The experiments are carried out in the office and hallway environments, including graph-based SLAM and autonomous exploration for mobile robots. The experimental results show the effectiveness of the proposed autonomous exploration framework. In the future research, we will address autonomous exploration in more challenging dynamic environments.
Pengenalan Individu Berdasarkan Gait Menggunakan Singular Value Decomposition Dan Jaringan Syaraf Tiruan Back Propagation

Gait atau cara berjalan setiap individu bisa dikatakan unik karena setiap individu umumya memiliki cara berjalan yang unik. Kelebihan lainnya biometrik dari gait dapat bekerja dalam jarak jauh. Pengenalan individu melalui webcam dengan masukan berupa video dapat menjadi alternatif lain untuk pengenalan individu biometrik selain dengan metode pengenalan biometrik lainnya seperti sidik jari dan iris mata. Tugas akhir ini mengimplementasikan metode reduksi data singular value decomposition (SVD) dan metode klasifikasi jaringan syaraf tiruan (JST) back propagation dalam identifikasi individu berdasarkan gait. Dengan mencari kombinasi parameter-parameter back propagation terbaik pada nilai epoch, learning rate, jumlah neuron hidden layer, dan target MSE dengan melakukan trial and error hingga menemukan nilai persentase akurasi optimal pada pengujian pengenalan individu. Output dari sistem ini adalah ketepatan dalam mengenali suatu objek berjalan. Singular value decomposition dengan jaringan syaraf tiruan back propagation memiliki pengenalan ciri yang cukup baik pada kasus pengenalan individu berdasarkan gait karena terbukti mampu memberikan nilai akurasi sebesar 90%. Akurasi ini dicapai pada traing JST back propagation dengan parameter jumlah neuron hidden layer 10, dengan epoch 1000, target MSE 1e-20, dan dengan parameter learning rate 0.01. Kata kunci : Gait, Singular Value Decomposition, Jaringan Syaraf Tiruan Back propagation