bluuebunny/crossref_metadata_2025 huggingface dataset:
Mobile Wall-Climbing Robot for NDT inspection of vertical concrete structures
Authors:   University of Zagreb, Božić Matej ,   University of Zagreb, Ćaran Branimir ,   University of Zagreb, Švaco Marko ,   University of Zagreb, Jerbić Bojan ,   University of Zagreb, Serdar Marijana
Published: January 2023

Concrete structures, such as bridges or viaducts, play an important role in global road infrastructure. These types of structures are relatively expensive to build and they are susceptible to outer external influences, which in time deteriorate and lead to the reduction of their structural resistance. To reduce this effect, regular inspection is needed, which is often done manually by using specialized equipment to reach certain parts of bridges and viaducts. This process is both expensive and dangerous for the inspectors to conduct. Within the research project ASAP (Autonomous System for Assessment and Prediction of Infrastructure Integrity) in order to overcome these challenges, we have developed a prototype of a wall-climbing robot (WCR) for nondestructive testing (NDT). In this paper, different iterations of the developed WCR prototypes are presented. In four consecutive prototype designs, we have evaluated and upgraded the adhesion and locomotion system. Finally, a fifth prototype that carries the NDT equipment is presented. The final version of the WCR is equipped with robust and flexible adhesion that enables the robot to adhere to different types of surfaces. We have also addressed the challenges of integrating NDT equipment into the robot. To successfully conduct an inspection, besides the WCR, a safety system, control, and power systems are needed, which are further presented and discussed.
Simulation-based deep learning model for the detection of imperfections in concrete structures
Authors:   Swiss Association for Technical Inspections, SVTI ASIT, Thurnherr Claudia ,   Swiss Association for Technical Inspections, SVTI ASIT, Muller Aurelia Marine ,   Swiss Association for Technical Inspections, SVTI ASIT, Algernon Daniel
Published: January 2023

The objective of the current study is the development of a deep learning model in order to detect and characterize relevant imperfections in steel reinforced concrete. Especially structural noise can affect the signal quality and needs to be considered. The application of deep learning algorithms requires a large and complete data set. However, experimental data acquisition is limited due to the designs and fabrication of test samples. Consequently, training a model only using experimental data is hardy possible in the current case. Hence, in this study various virtual ultrasonic inspections are conducted with the commercial simulation software CIVA. The simulation takes into account structural noise in order to model the imperfections as realistic as possible. Different types of imperfections are considered such as honeycombs. Using simulation offers the chance to generate a large data set which is required for the training of deep learning models. Furthermore, the parameters can be systematically varied within the simulation which guarantees a complete data set. The simulated inspection data which contains noise is used to train a deep learning model with the internally developed software Echolyst A.I.. Finally, the model is validated with experimental data of honeycomb inspections. The study shows the potential of artificial intelligence in order to significantly increase the effectivity of ultrasonic inspections of imperfections in steel reinforced concrete structures.
Application of simulation software for NDT for civil engineering
Authors:   EXTENDE, Foucher Fabrice ,   EXTENDE, Fernandez Roman ,   Swiss Association for Technical Inspections, SVTI ASIT, Algernon Daniel ,   Commissariat Energie Atomique (CEA), Leberre Stéphane ,   Commissariat Energie Atomique (CEA), Leymarie Nicolas ,   Commissariat Energie Atomique (CEA), Dorval Vincent
Published: January 2023

Simulation is a powerful means in the design of inspection methods. It minimizes the number of iterations when building probe prototypes, optimizing inspection techniques and defining the test procedures. It is known to be valuable in supporting performance and reliability demonstrations requiring a lot of data (e.g., POD studies and qualification campaigns), where simulation can reduce the number of necessary mock-ups and experimental trials. Largely used in different industrial sectors, there is still great potential for NDT modelling remaining in the civil engineering field. The aging infrastructures, and the increasing needs for reliable evaluations of structural integrity require deeper investigations and developments, in which modelling can be of great help.
The CIVA platform is a well-established multi technique simulation and analysis software in NDT. Developed by CEA LIST, but also resulting from the contribution of numerous industrial and academic partners within Europe, it implements concepts of numerical efficiency, imaging, and reliability demonstration. The range of NDT methods in CIVA includes UT, GWT, ET, RT, CT, Thermography and is extended by Structural Health Monitoring applications based on guided ultrasonic waves.
In addition to physical models dedicated to metallic inspections largely used in the industry, CIVA offers the capacity to simulate ultrasonic inspections in other media such as concrete. It has recently included the definition of probes polarized to generate shear waves at 0°, thus capturing the current state-of-the art for concrete inspections. This contributes significantly to the potential for studies and inspection planning in the field of concrete inspections, which helps tremendously in ensuring reliable inspections. While such studies would require enormous computational effort for most other simulation techniques, the semi-analytical approach of CIVA makes it highly efficient and application-oriented.
This paper illustrates models available in the ultrasonic module of CIVA and best practices for application cases in civil engineering.
Detecting Changes in Boundary Conditions based on Sensitivity-based Statistical Tests
Authors:   University of British Columbia, Mendler Alexander ,   Institut national de recherche en informatique et en automatique (INRIA), Döhler Michael ,   BAM Federal Institute for Materials Research and Testing, Hille Falk
Published: January 2023

Structural health monitoring is a promising technology to automatically detect structural changes based on permanently installed sensors. Vibration-based methods that evaluate the global system response to ambient excitation are suited to diagnose changes in boundary conditions, i.e. changes in member prestress or imposed displacements. In this paper, these changes are evaluated based on sensitivity-based statistical tests, which are capable of detecting and localizing parametric structural changes. The main contribution is the analytical calculation of sensitivity vectors for changes in boundary conditions (i.e., changes in prestress or support conditions) based on stress stiffening, and the combination with a numerically efficient algorithm, i.e. Nelson’s method. One of the main advantages of the employed damage diagnosis algorithm is that, although it uses physical models for damage detection, it considers the uncertainty in the data-driven features, which enables a reliability-based approach to determine the probability of detection. Moreover, the algorithm can be trained and the probability of detecting future damages can be predicted based on data from the undamaged structure—in an unsupervised learning mode—making it particularly relevant for unique structures, where no data from the damaged state is available. For proof of concept, a numerical case study is presented. The study assesses the loss of prestress in a two-span reinforced concrete beam and showcases suitable validation approaches for the sensitivity calculation.
Full-waveform inversion of ultrasonic echo signals to evaluate grouting quality of tendon ducts in post-tensioned concrete structures
Authors:   Mondaic AG, Krischer Lion ,   IMP Bautest AG, Strobach Elmar ,   Mondaic AG, Boehm Christian ,   Mondaic AG, Afanasiev Michael ,   ETH Zürich, Angst Ueli
Published: January 2023

Reliable techniques for non-destructive evaluation of reinforced and prestressed concrete structures are of utmost importance for the maintenance of aging infrastructure. A particular area of interest is the evaluation of grouting quality within tendon ducts in post-tensioned concrete. Detecting voids and water-filled cavities in plastic or metal ducts is challenging, especially at greater depths or in the vicinity of rebar. Conventional non-destructive inspection methods based on elastic waves, such as impact-echo or ultrasonic pulse echo method using synthetic aperture focusing and/or signal phase analysis, often lack sensitivity to those defects and/or rely on manual and subjective interpretation of the complex data.

To overcome these problems, we present a synthetic feasibility study based on full-waveform inversion for reliable ultrasonic non-destructive testing. Full-waveform inversion is a powerful imaging technique that infers tomographic reconstructions of the material properties from ultrasound measurements. The method is widely used for geophysical applications based on seismic waves and has recently gained increasing attention for ultrasonic inspection applications.

Using digital twins, we demonstrate the effect of voids and water inclusions on simulated ultrasonic echo signals. This information can be used in an iterative inversion algorithm to create a 3-D quantitative model of the specimen’s interior. We showcase in several numerical examples that even under uncertainties regarding aggregate size distribution and location of the rebar, full-waveform inversion can reveal defects related to the tendon ducts, which enables a robust and automated assessment of the grouting quality.
The Influence of Temperature Control on Labour Productivity on Masonry Work
Authors: BAMFO-AGYEI Emmanuel , EGAN Charles Akun
Published: January 2023

Purpose: This research focused on the influence of temperature on labour productivity on construction sites. Design/ Methodology/ Approach: A case study of a construction site at Cape Coast Technical University was adopted for the study, the sampling technique was a purposive method and the sample size was 100 which include contractors, site supervisors, masons, concrete operator and general foreman. The body temperatures of the gang were taken and catalogued to see how each worker fared in terms of their temperature throughout the working times and under the influence of the weather as the concrete work and block work were carried out. Labour output for the block work was measured by the area of block work laid per period and the concrete work was also measured. Findings: It can be seen that the mean body temperatures of the workers fluctuated in the day as work progressed. This was attributed to the fact that the sun’s intensity gradually increased overtime peaking at noon throughout the early afternoons. In the first and second hours of work, produced 2.172m3 of concrete each. The third and fourth hours produced 1.689m3 of concrete each and the fifth hour produced 1.44m3 of concrete. Based on the resulting productivity reduced steadily as temperature increases and at a temperature of 37degree Celsius the productivity of the labour output dropped to 1.44 m3. Research Limitation/ Implications: The study focused on the influence of temperature on construction labour productivity of masonry works. Practical Implication: The knowledge advanced in this study will inform construction managers of the factors that significantly influence construction labour productivity of masonry work to temperature. It will assist the construction managers to select a suitable period of the day to carry out the task when the temperature will not harm the construction workers. Social Implication: The knowledge advanced by this study will help policy-makers in the construction industry to review the existing national labour-intensive public works policy which is geared towards helping indigenous firms in improving productivity in the construction industry. Originality/ Value: The novelty of this study also lies in the labour productivity measurements that will guide construction managers to identify periods of the day that will not pose a hazard to the workers when executing their tasks. Keywords: Construction Management: Labour: Masonry: Productivity: Temperature: Ghana.
Impact of Defence Expenditure on Capital Market Growth in Nigeria
Authors: SHU’ARA Jamila , OLAOLU Oladele Emmanuel
Published: January 2023

Abstract: Despite the government huge funding of defence and other security related matters, insecurity seems to be on the increase across the geopolitical zones in Nigeria. This development could stifle inflows of investments into the country. However, the Nigeria Capital market is adjudged to be among of the vibrant markets globally notwithstanding of the seeming security challenges. This paper examined the impact of defense expenditure on Capital market growth in Nigeria from 1984 to 2019. The study adopted ex post facto research design, and data sourced were from the Central Bank of Nigeria Statistical Bulletin for 35 years. Time-series data extracted related to market capitalization, recurrent defense expenditure and capital defense expenditure from CBN Statistical Bulletin were used for the study. The study employed multiple regression analysis in determining the impact among the variables under investigation. The findings from the Johansen cointegration test indicate a long-run relationship among the variables in the study. The result from the Error Correction Model indicates that recurrent defense expenditure and capital defence expenditure impacts market capitalization positively and significantly both in the short and long run. It was recommended that government spending should be such that it affects market activities positively via policies that are geared boosting investment in the capital market. It was also recommended that policymakers from the fiscal end to collaborate with their monetary counterparts to formulate strategic policies that relates to defence expenditure that will boost the overall growth of the capital market both in the short and long run. Keywords: Market Capitalization: Recurrent Defence Expenditure: Capital Defence Expenditure: Nigeria.
Socio-Economic Status of Tribal Women in Tiruvannamalai District of Tamil Nadu
Authors: A. RANJITHKUMAR , DIMITROV B. E. George
Published: January 2023

Abstract: Since history tribal women have faced problems on basis of two aspects, first one is caste discrimination and Caste discrimination is the social evil. Caste discrimination is a social evil. Various legal measures are being implemented to eliminate caste discrimination. However, caste discrimination could not be stopped. This discrimination is still practiced in the society till today. Second one is gender discrimination and women are not treated equally to men. Women are treated as inferior to men and they do not even get their basic rights. Their rights are denied by men. In these backgrounds the study tries to investigate historical perspectives of tribal and women and to understand socio economic status of Tribal women in Tiruvannamalai district of Tamil Nadu. Keywords: Tamil Nadu: Caste System: Tribal Women: Economic Status: Socio-Economy: India
Late Miocene Dasypodidae Gray, 1821(Xenarthra, Cingulata) from the Toro Negro Formation (Central Andes, Argentina): diversity and chronological and biogeographical implications
Authors: BRANDONI Diego , BARASOAIN Daniel , RUIZ Laureano R. GONZÁLEZ
Published: January 2023

Fossil remains herein described are referred to different species of Dasypodidae Gray, 1821 (Mammalia, Xenarthra, Cingulata) and come from the upper levels of the lower member (Late Miocene-Early Pliocene) of the Toro Negro Formation at Quebrada de Las Torrecillas, La Rioja Province, Argentina, where previous vertebrate records only include those of Pyramiodontherium scillatoyanei De Iuliis, Ré & Vizcaíno, 2004 (Mammalia, Xenarthra) and Opisthodactylus cf. kirchneri Noriega, Jordan, Vezzosi & Areta, 2017 (Aves, Rheidae). The remains of Dasypodidae herein presented include Vetelia ghandii Esteban & Nasif, 1996, Chasicotatus peiranoi Esteban & Nasif, 1996, Macrochorobates scalabrinii (Moreno & Mercerat, 1891), Prozaedyus sp., and Paleuphractus argentinus (Moreno & Mercerat, 1891), and constitute the first records of these species for the Toro Negro Formation, increasing the mammal diversity for this unit. The association of dasypodids here described shows strong affinities with those described for Late Miocene localities of Northwestern Argentina. Under these evidences, the Dasypodidae here reported for Quebrada de Las Torrecillas site show a characteristic association of taxa from Northwestern Argentina, suggesting a Messinian age (Late Miocene) for the bearing levels of the Toro Negro Formation. In this way, these records support the accurate ages recently proposed for the lower Member of the Toro Negro Formation (i.e., Late Miocene-Early Pliocene).
Quadrotor physical parameters online estimation
Authors:   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Cortés-Benito I. , Rodríguez-Cortés H. ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Martínez-Ramírez M. ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Tlatelpa-Osorio Y. ,   Instituto Tecnológico Autónomo de México, Romero J. G. ,   Instituto Tecnológico Autónomo de México
Published: January 2023

Online estimation of unmanned aerial vehicles' physical parameters is an essential tool for aerodynamic and control design. This paper numerically evaluates two methods for physical parameter estimation for a quadrotor. The estimation methods are based on recently introduced techniques that relax the persistency of excitation constraint in the least-squares estimation methods.
IoT-Based CO2 Monitoring and Forecasting System to Prevent Transmission of COVID-19
Authors:   Tecnologico Nacional de Mexico, I.T. Tuxtla Gutierrez, Marquez-Zepeda M. J. , Santos-Ruiz I. ,   Tecnologico Nacional de Mexico, I.T. Tuxtla Gutierrez, Pérez-Pérez E. J. ,   Tecnologico Nacional de Mexico, I.T. Tuxtla Gutierrez, Hernández-de León H. R. ,   Tecnologico Nacional de Mexico, I.T. Tuxtla Gutierrez
Published: January 2023

This paper presents the development of low-cost CO2 remote monitoring devices based on NDIR sensors, and the design of a Nonlinear Autoregressive Neural Network (NAR) that forecasts the indoor CO2 concentration in the short and medium term to avoid risks of SARS-CoV-2 contagion due to the accumulation of poor quality air previously breathed by other people. Different configurations of the NAR were analyzed, varying the number of layers, the number of neurons per layer and the number of input delays. The best network configurations predicted changes in CO2 concentration in an academic office up to a four-hour horizon with an RMS error around 30 ppm.
A study on performance and fragility of controllers: PR and PD
Authors:   Universidad Autónoma Metropolitana, Oaxaca-Adams Guillermo , Villafuerte-Segura Raúl ,   Universidad Autónoma del Estado de Hidalgo
Published: January 2023

This paper presents a study on the fragility and performance of two linear controllers for second-order systems: proportional retarded control (PR) and proportional derivative control (PD). The study is carried out through an analysis of the corresponding characteristic equation of the closed-loop system. In the case of the PR control, Taylor’s theorem is used to show that if there exits a root of multiplicity three, it is necessarily dominant.
Control based on a hybrid predictor for linear unstable delayed systems with a pair of complex conjugate poles
Authors:   Instituto Politécnico Nacional, Urquiza Castro A. , Navarro Corro R. ,   Instituto Politécnico Nacional, del-Muro-Cuéllar B. ,   Instituto Politécnico Nacional, Vázquez-Guerra R. J. ,   Instituto Politécnico Nacional, Márquez Rubio J. F. ,   Instituto Politécnico Nacional
Published: January 2023

This paper presents a methodology to design a hybrid predictor of continuous signals to solve the stabilization problema of unstable linear systems with time delay, specifically systems with an unstable pole and a pair of stable conjugate complex poles. Among the main contributions of this work is to guarantee the existence of the predictor device, regardless of the size of the delay. To solve the stabilization problem, the necessary and sufficient conditions are obtained for a Proportional-Integral (PI) controller that can guarantee the stability of the system using the designed predictor. The performance of this control strategy is evaluated by means of a numerical simulation.
Control Applications Using Reinforcement Learning: An Overview
Authors:   Tecnológico Nacional de México/IT Tuxtla Gutiérrez, Rodríguez Sánchez Francisco , Santos-Ruiz Ildeberto ,   Tecnológico Nacional de México/IT Tuxtla Gutiérrez, Domínguez-Zenteno Joaquín ,   Tecnológico Nacional de México/IT Tuxtla Gutiérrez, López-Estrada Francisco Ronay ,   Tecnológico Nacional de México/IT Tuxtla Gutiérrez
Published: January 2023

This article presents the general formulation and terminology of reinforcement learning (RL) from the perspective of Bellman’s equations based on a reward function, its learning methods and algorithms. The important key in RL is the calculation of value-state and value state-action functions, useful to find, compare and improve policies for learning agent through different methods based on values and policies such as Q-learning. The deep deterministic policy gradient (DDPG) learning algorithm based on an actor-critic structure is also described as one of the ways of training the RL agent. RL algorithms can be used to design closed loop controllers. Through simulation, using the DDPG algorithm, an example of the application of the inverted pendulum is proposed in simulation, demonstrating that the training is carried out in a reasonable time, showing the role and importance of RL algorithms, like tools that combined with control can address this type of problems.
Static Output Feedback Controller Design for Nonlinear Descriptor Systems Via Relaxed LMI Conditions
Authors:   Universidad Politécnica de Pachuca, Gutiérrez Ricardo , González-Sierra Jaime ,   Universidad Politécnica de Pachuca, Hernandez-Cortes Tonatiuh ,   Universidad Politécnica de Pachuca, Estrada-Manzo Victor ,   Universidad Politécnica de Pachuca, Bernal Miguel ,   Institute of Technology, Ciudad Obregón
Published: January 2023

This paper presents an alternative to design a static output feedback controllers for nonlinear descriptor systems. The methodology is based on the direct Lyapunov method, from which, after a convex rewriting of the original nonlinear systems, conditions in the form of linear matrix inequalities are obtained. The proposal is shown to be more relaxed than previous ones in two ways; first, unmesaurable nonlinearities can be directly considered and, second, more flexibility can be obtained with the selection of different slack variables; such advantages are illustrated via numerical examples.
Low-cost DSP-based vibration data acquisition system for bearing fault detection in electric motors
Authors:   TecNM/Instituto Tecnológico de Aguascalientes, Villalobos-Piña F. J. , Saucedo-Zarate C. H. ,   TecNM/Instituto Tecnológico de Aguascalientes, González-García M. A. ,   Universidad Autónoma de San Luis Potosí, González -Murillo L. A. ,   Universidad Autónoma de San Luis Potosí, Alvarez-Salas R. ,   Universidad Autónoma de San Luis Potosí, Reyes-Malanche J. A. ,   Universidad Tecnológica de Aguascalientes
Published: January 2023

This paper presents a low-cost DSP-based vibration data acquisition system with a high data storage capacity for fault detection in electric motors. An outer race bearing fault detection case study for a three-phase induction machine using vibration signals provided by the DSP-based acquisition system from a test rig is detailed. The fault detection scheme is performed based on Fast Fourier Transform (FFT) and Discrete Wavelet Transform (DWT).
Automation of a drilling process via a wireless connection using the EMQX protocol
Authors:   Universidad Tecnológica de la Mixteca, Orantes-Molina A. , Juárez-Abad J. A. ,   Universidad Tecnológica de la Mixteca, Linares-Flores J. ,   Universidad Tecnológica de la Mixteca, Miranda Luna Rosebet ,   Universidad Tecnológica de la Mixteca
Published: January 2023

This paper proposes an alternative solution to automate a system called “Drill Station." Our automation proposal focuses on wireless communication between a GUI and a PLC S7-200 CPU 226 from the manufacturer Siemens to achieve remote control and monitoring of the process. In our proposal, the enriched production Grafcets diagrams and the security Grafcet diagrams are used with the transfer-type process forcing order. The process consists of three work areas: loading, drilling, testing, and evacuation of the part. We showed that with the use of Grafcets, it is possible to fully automate the process, considering the various running, operating, and safety modes, to improve the operation, achieve a better understanding of the drive, and facilitate the training of the operators.
On Disturbance Rejection for a Class of Underactuated Hamiltonian Systems
Authors:   Universidad Nacional Autónoma de México, Ramos-García Fernanda , Estopier de la Cruz Jorge Alberto ,   Universidad Nacional Autónoma de México, Espinosa-Pérez Gerardo ,   Universidad Nacional Autónoma de México
Published: January 2023

In this work, the problem of additive perturbations is studied for a class of port Control Hamiltonian (PCH) systems. The considered class of Hamiltonian systems includes underactuated systems, which continue to be an important open study area. The starting point of the used methodology begins by considering that a previous tracking control has already made the equilibrium point of the error dynamic system asymptotically stable. The Integral Control (IC) reported in cite{ortega2012robust} and cite{ferguson2017integral} are implemented in the PCH class system so that it can reject the constant additive perturbations and conserves the Hamiltonian system structure. The results are compared and tested in a studied case with the system application of the Permanente Magnet Synchronous Motor (PMSM), and the MATLAB Simulink simulations obtained are exposed to compare the performance of both controls.
Kinetic modelling of a dark fermentation process using tequila vinasses as substrate for hydrogen production
Authors:   Universidad de Guadalajara, Díaz Carreón Ninfa Alexandra , Gurubel Tun Kelly Joel ,   Universidad de Guadalajara, Sulbarán Rangel Belkis Coromoto ,   Universidad de Guadalajara, León-Becerril Elizabeth ,   Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, García-Depraect Octavio ,   Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco
Published: January 2023

In this work, a search methods strategy based on optimization algorithms is proposed for the kinetic modelling of a dark fermentation process using tequila stillage substrate for hydrogen production. Kinetic model based on the ADM1 approach is fitted to the experimental data to evaluate the dynamic behaviour of the metabolites produced and consumed during the mixed-culture fermentation. This batch fermentative process is based on mass balance analysis and correlated kinetic expressions following a Monod type dependence. In previous works, batch experiments were performed using different substrates to characterize the metabolic transformations involved in hydrogen production. Where, a kinetic model was developed and fitted to the obtained temporal profiles using Matlab and Excel solvers, allowing a satisfactory description of the metabolic pathways leading to hydrogen production. The aim of this research is to show the efficacy of the proposed optimization strategy to find the kinetic parameters of the model that will allow predictions on the behaviour of hydrogen production.
Development of a 6-DOF robot for haptic interaction with complex virtual environments
Authors:   Universidad Nacional Autónoma de México, Alonso-Torres Brayan , Castro-Díaz José Daniel ,   Universidad Nacional Autónoma de México, López-Rodríguez Mauro ,   Universidad Nacional Autónoma de México, Arteaga Marco ,   Universidad Nacional Autónoma de México
Published: January 2023

In the last decade, the design and implementation of robots have taken a turnaround in areas such as haptics and virtual reality. Unlike the big and heavy industrial robots, haptic ones must be light and suitable to be easily handled by an operator. Moreover, they must have enough actuators to allow a realistic haptic interaction with a complex virtual environment. In this work, we present the two phases Research and Development process of a six-degrees-of-freedom haptic robot. In the first phase, we build on our previous work to design a spherical wrist, improving both the mechanics and electronics of an old one. In the second phase, we design a virtual environment consisting of a ball and beam system with which the operator interacts visually and haptically. The basis of our development is the well-known Novint Falcon parallel robot that acts as the first 3-DOF of the resulting device. The rest is completed with our improved spherical wrist, in which a 6-DOF force sensor that measures the interaction forces between the virtual environment and the operator was mounted. Our ultimate goal is to evaluate the usability of the obtained haptic robot and present it as a viable alternative to current commercial devices.
Evolutionary Algorithm to Auto-tuning Hyperbolic Tangent Sliding-Mode Controllers
Authors:   Instituto Politécnico Nacional, Hernández Francisco David , Cortes Domingo ,   Instituto Politécnico Nacional, Vargas Maria Margarita ,   Instituto Politécnico Nacional
Published: January 2023

In recent years, control engineers has started to explore new control, optimization and tune paradigms. And they have found that Evolutionary Algorithms (EA) are good alternatives for traditional methods. Thanks to the power to explore high search-spaces with multicombinational problems and a lot of potential solutions. For this reason, in this work an Evolitive Algorithm is planned as a heuristic auto tunning algorithm for Sliding-Mode Controllers. Using an approach by Hyperbolic Tangents. In order to obtain easily implementable control laws with a desirable performance to linear and non-linear systems.
Bl-homogeneous sliding-mode observers for SISO linear time-varying systems with unknown input
Authors:   Universidad Nacional Autónoma de México, Meléndez-Pérez René , Moreno Jaime A. ,   Universidad Nacional Autónoma de México, Fridman Leonid ,   Universidad Nacional Autónoma de México
Published: January 2023

In this article, a family of state observers with bl- homogeneous properties is proposed for a class of linear systems with time-varying coefficients, in presence of an unknown input and with an arbitrary relative degree. The proposed observers converge globally and at least asymptotically to the true states for systems that satisfy the structural property of strong observability. With an adequate selection of gains and parameters the convergence is global and theoretically exact, in finite time or even more, in fixed time.
Modeling Infectious Diseases via Integral Delay Equations
Authors:   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ortiz Reynaldo , Saldivar Belem ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mondíe Sabine ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional
Published: January 2023

Integral delay equations (IDE) have several applications, they can be found in mathematical models of population and propagation of infectious diseases. Many of these models are sets of non-linear integral delay equations similar to the classical SEIR models, but with the advantage of simplifying the number of equations with a simple change of variable. An alternative equation is the well known renewal equation which can model both demographics and infectious diseases, we focus on the disease model and establish the equivalence between the versions with a single finite delay and the one with multiple delays, both obtained from a histogram of relative frequencies of tracking data of the infected people. We compare their Lyapunov matrices and the stability analysis when the reproductive number is in matrix form.
Dynamic Modeling and Backstepping Control of a Wheeled Mobile Robot With Skidding and Slipping effects
Authors:   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Aguilar-Pérez J. I. , Velasco-Villa M. ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Castro-Linares R. ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, González-Sierra Jaime ,   Unidad Profesional Interdisciplinaria de Ingeniería Campus Hidalgo
Published: January 2023

The development of a tracking control using a backstepping method for a wheeled mobile robot under the effect of skidding and slipping is presented in this paper. The dynamic model of a differential drive mobile robot with skidding and slipping effects is used to solve the trajectory tracking problem. The proposed control scheme is based on a backstepping strategy and under the assumption of knowledge of the disturbance. Simulations results are showed, to prove the effectiveness of the proposed method together with a comparison with similar strategies already presented in the literature.
New energy-shaping based control plus an integral action for torque-driven robot manipulators using coordinate changes
Authors:   Instituto Tecnológico de La Laguna, Torreón, Coahuila, Cervantes Luis , Santibáñez Víctor ,   Instituto Tecnológico de La Laguna, Torreón, Coahuila, Sandoval Jesús ,   Tecnológico de La Paz, La Paz, Baja California Sur
Published: January 2023

This paper presents a robust energy shaping control for joint position tracking of torque-driven robot manipulators against disturbances. The controller design is based on an alternative energy shaping method, and an integral action is added to the theoretical framework as a novel strategy. Our contribution is to globally achieve joint position tracking of torque-driven robot manipulators, even in the presence of constant disturbances. The performance of the proposed controller is illustrated through experiments of a two degrees of freedom direct-drive robot arm.
Comparison of control algorithms for a PMSM electrical machine
Authors:   Universidad Autónoma del Estado de Quintana, Aguirre F. , Aguilar J.O. ,   Universidad Autónoma del Estado de Quintana, Vazquez J. ,   Universidad Autónoma del Estado de Quintana, Chan F. ,   Universidad Autónoma del Estado de Quintana, Becerra G. ,   CONACYT-Universidad Autónoma del Estado de Quintana, Avilés J. D. ,   Universidad Autónoma de Baja California, Benitez M. ,   Instituto Tecnológico Superior de Purísima del Rincón
Published: January 2023

This paper describes the comparison of some control algorithms applied to nonlinear dynamics of the electric machine model, which uses the Park transformation for the simplified representation. The applied controllers focus on the designs of, passivity, sliding modes as well as linearization. The objective of the comparison is to identify the most appropriate design for the user’s application, where the gains of the control algorithms are modified, which is reflected in the response of the system in addition to the energy consumption, which in most works it is not analyzed.
Non-homogeneous observer-based-output feedback scheme for the double integrator
Authors:   Universidad de Guadalajara, Cruz-Zavala Emmanuel , Nuño Emmanuel ,   Universidad de Guadalajara, Moreno Jaime A. ,   Universidad Nacional Autónoma de México
Published: January 2023

In this paper we propose a non-homogeneous observer-based-output feedback scheme for the double integrator system. The control scheme is composed by two non-homogeneous structures. It resembles a non-homogeneous state feedback controller, where the unmeasurable state is replaced by the that provided by a non-homogeneous observer. Compared to other reported schemes, the closed-loop system is not homogeneous of negative degree, so it is not possible to use the results established for homogeneous systems. To overcome this problem, the finite-time stability analysis is carried out by means of (local) strict Lyapunov functions.
Extended Luenberger observer for a biodiesel production process with heterogeneous catalyst
Authors:   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, González García Ana Paloma , Díaz Jiménez Lourdes ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Padmadas Padamsree K. ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Hernández Salvador Carlos ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional
Published: January 2023

The biodiesel production process requires low-cost and real-time monitoring. In this document, an extended Luenberger observer was designed to provide on-line estimation of the concentration of triglycerides, methanol, biodiesel, and glycerol. To this end, a mathematical model based on energy and mass balance equations as well as the global transesterification reaction in a batch reactor was considered. The model consists of two nonlinear differential equations, one output equation, and four complementary equations. The simplification of the model was used through a linearization procedure, considering two state variables (reaction rate and temperature) and one output variable (temperature). This procedure allowed to use estimation strategies typical of linear systems. The LQR method was used to calculate the gain observer. A fast convergence (compared to the total reaction time) of the observer was obtained despite varying the initial conditions up to 30%. Thus, it was concluded that the extended Luenberger observer, using temperature as the only output, allows estimating the conversion of triglycerides to biodiesel.
Text Mining Methodology for Building Water Leak Maps from Tweets
Authors:   Universidad Nacional Autónoma de México, Torres Lizeth , Ramírez-Chavarría Roberto G. ,   Universidad Nacional Autónoma de México, Jiménez-Magaña Martín R. ,   Universidad Nacional Autónoma de México, García-Franco Lucero F. ,   Universidad Autónoma Metropolitana
Published: January 2023

This article presents a text mining methodology that is used in the framework of a project called Fugometría. The objective of the proposed methodology is the construction of maps with markers that indicate the location of water leaks. To achieve this purpose, the initial step is the collection of tweets issued by citizens to report the existence of leaks in drinking water distribution networks. Once these tweets are collected, they are parsed for an address in the body of the message. If an address is detected, it is converted into a GPS coordinate, which is in turn used to build a map with markers indicating the location of water leaks. In order to show the applicability of the methodology, some preliminary results on the construction of a leak map of Mexico City are shown.
Collision avoidance for second-order mobile robots
Authors:   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Parra-Marín Andrés , Aranda-Bricaire Eduardo ,   Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, González-Sierra Jaime ,   Instituto Politécnico Nacional
Published: January 2023

This paper addresses the collision avoidance problem for a group of two second-order mobile robots. The proposed control strategy is composed of a part that achieves a desired formation, based on the Fundamental Consensus Algorithm, which ensures that agents converge to the desired formation. On the other hand, Artificial Vector Fields (AVF) are used for collision avoidance. Furthermore, a parameter is designed to allow an adequate scaling of the AVF and to ensure non-collision. Numerical simulations are presented to validate the performance of the proposed control strategy.
On the synchronization of selfexcited and hidden attractors
Authors:   Instituto Potosino de Investigación Científica y Tecnológica, Barajas-Ramírez Juan Gonzalo
Published: January 2023

Many nonlinear systems have complex behaviors where selfexcited and hidden attractors exist and some times coexist. We investigate the synchronization problem for these type systems under two different coupling configurations: drive-response and bidirectional. In the first scheme, the coupling term in the response subsystem can be design as an output feedback controller to achieve synchronization; while in the latter, since the states of both systems depend on their interaction, the coupling terms are designed in terms of their differences. As observed before synchronized behavior on a hidden attractor is very difficult to achieve. In this sense our results show that for the drive-response configuration is relatively simple to impose a synchronized behavior; however, on hidden attractors the region of attraction of the synchronized solution reduces to that of the hidden attractor. Additionally, in a bidirectional configuration the region of attraction of the synchronized behavior basically disappears making the design of a static coupling considerably more difficult. We illustrate our results with numerical simulations of systems with hidden and selfexcited attractors.
Adaptive Integral Terminal Sliding Mode Guidance and Control for a UUV Under Perturbations
Authors:   Tecnológico de Monterrey, Sánchez-Calvo Andrés E. , Martínez-Pérez Sebastián ,   Tecnológico de Monterrey, González-García Alejandro ,   Tecnológico de Monterrey, Castañeda Hermán ,   Tecnológico de Monterrey
Published: January 2023

This article addresses robust guidance and control for a fully-actuated underwater autonomous vehicle under external perturbations. A cascade strategy based on an adaptive integral terminal sliding mode controller is designed. Such approach ensures practical finitetime convergence of the tracking errors and robustness against disturbances with unknown boundaries. In addition, it does not overestimate the control gain, reducing chattering. The guidance law forces the vehicle to track desired trajectories, providing velocity and heading references for all degrees of freedom. Then, a low-level control ensures convergence of all the state variables. Finally, simulations results carried on a full model subject to water currents prove the feasibility and advantages of the proposed control scheme.
PENGARUH PENERAPAN STRATEGI PAKEM TERHADAP HASIL BELAJAR IPA PADA SISWA KELAS IV MIN LABUI
Authors: Faisal
Published: January 2023

The purpose of the study was to determine the effect of the implementation of the PAKEM strategy on the science learning outcomes of the fourth grade students of MIN Labui and to determine whether there was an effect of the PAKEM strategy on the science learning outcomes of the fourth graders of MIN Labui. This study uses classroom action research, using Kurt Lewin's model, which states that: in one cycle consists of four main steps : planning, acting, observing and reflecting. The results of the CAR research through the Influence of the Implementation of PAKEM Strategy on Science Learning Outcomes in Grade IV Students of MIN Labui in cycle I showed the average value of student evaluation was 6.42%. Student learning outcomes in cycle II were also not good, but the second cycle meeting students have had a slight change, students have dared to ask the teacher about natural resource material that they have not understood, the average value of students in cycle II is 7.10%. Teacher and student learning activities are maximized and in cycle III student learning outcomes already optimal,  8.17%
PENERAPAN METODE PRAKTIKUM UNTUK MENINGKATKAN PEMAHAMAN KONSEP MAHASISWA PADA MATA KULIAH KONSEP DASAR IPA II
Authors: Gusti Handayani
Published: January 2023

The aim of this research is to know the implementation of experiment method to increase students’ understanding on concept in Konsep Dasar IPA II course. The kind of research done was Classroom Action Research. Which consisted of two cycles. The subject of the research was The undergraduate students of PGMI semester III class 1. The number of the students were 37. The result indicated that the students got improve in each cycle. In cycle I, Activity 1 and 2 the students were in the fair level, while in activity 3 until 6 stepped up into good level. Next, in cycle II, activity 1 until 4 the students got good, while four other activities got very good. Meanwhile the students understanding got improve from cycle 1 to cycle 2 with the mean score of the test was 77.0 while  cycle II was 77.45. The improvement from pre test to cycle I was 11.55 point, for cycle II the improvement was 12 point. So, the conclusion is the experiment method can improve students’ understanding on concept.
KARAKTER PENUNTUT ILMU DALAM PERSPEKTIF ISLAM
Authors: Bukhari
Published: January 2023

Character for science prosecutors in Islamic perspective is a principle that needs to be considered by knowledge pursuers. In the view of Islam it can be illustrated that there are four ethics namely the application of good intentions before occupying itself as someone who seeks knowledge. Choosing the right teacher for him, one of the teachers is able to do the commands of Allah in accordance with His Shari'a and is able to stay away from it. Every work carried out by someone will begin with prayer and earnest effort, because the key to success is based on the belief and trust in someone. This condition must be occupied by someone and character formation will occur for the prosecutors of Islamic religious knowledge.
PENGARUH EFEKTIFITAS PEMBELAJARAN AQIDAH AKHLAK TERHADAP KEPRIBADIAN SISWA
Authors: FUAD
Published: January 2023

The nature of students learning the subject of aqeedah morals is to instill morality in the personality of each individual in the process of teaching and learning in particular and in everyday life in general, then the aim of teaching aqeedah morals to students in Madrasas is solely to improve the devotion of children in particular and in daily life in general. educate God Almighty and have noble character in his life, both with the teacher and the community in their daily lives, Effectiveness is an effort made by the teacher in the teaching and learning process. Learning Should be with the effectiveness of moral aqidah learning will affect student personality towards better learning and teaching processes. Efforts to effectiveness the learning of moral aqidah is something that must be carried out by the teacher without exception. But what has happened so far is that not all teachers make effective the learning of aqidah morals in learning. Should be able to change the personality of students towards better learning, then all teachers must implement the effectiveness of learning aqidah morals to students