bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intrinsic time decomposition based differential protection with adaptive threshold for UPFC compensated transmission line
Authors: Panday Ajay , Patidar Ram Dayal , Biswal Sandeep 
Published: December 2021

Abstract
In the presence of nonlinear response created by power electronics-based compensators, reliable fault detection and classification by distance protection relays is a major concern. The unified power flow controller (UPFC) has a dynamic characteristics that causes stability and protection issues. A intrinsic time decomposition (ITD) based strategy is proposed for addressing this issue. A differential energy based detection index computed using ITD and adaptive thresholding technique is employed such that unerring fault detection is achieved wherein faulty phases of a UPFC compensated transmission line are well pointed out. Various fault and non-fault cases considering critical power system conditions are analysed for power systems with varying configurations modelled using EMTDC/PSCAD. A comparison of the current detection method to recently proposed techniques reveals the benefits and feasibility of the presented detection strategy, which has been proved to be accurate and efficient.
A reliable islanding identification mechanism for DC microgrid using PCC transient signal
Authors: Prince Satyavarta Kumar , Panda Kaibalya Prasad , Affijulla Shaik , Panda Gayadhar 
Published: December 2021

Abstract
The islanding detection is a major problem for both AC and DC Microgrids. Failure to do so may result in problems such as system instability, increased non-detection zone, out-of-phase reclosing, personnel safety, and power quality deterioration. To address this issue, this paper presents a reliable island identification method for DC Microgrids that employs a Cumulative Sum of Rate of change of Voltage (CSROCOV) to reduce the non-recognition region. The proposed islanding protection scheme employs point of common coupling (PCC) transient signal to detect islands events. The voltage, power, and current sampling are accumulated from the PCC of the distributed generation terminals. The proposed scheme detects islanding in three test cases with varying power mismatching conditions, while non-islanding events are classified as capacitor switching and faults. The system is modelled and simulated in the MATLAB/Simulink environment, then islanding conditions are applied by turning off the main circuit breaker. Simulation results are presented to verify the methodology under different test cases. The robustness of the proposed scheme is also validated against measurement noise.
COVIDX: Computer‐aided diagnosis of COVID‐19 and its severity prediction with raw digital chest X‐ray scans
Authors: Abbasi Wajid Arshad , Abbas Syed Ali , Andleeb Saiqa , Bibi Maryum , Majeed Fiaz , Jaleel Abdul , Akhtar Muhammad Naveed 
Published: December 2021

BackgroundCoronavirus disease (COVID‐19) is a contagious infection caused by severe acute respiratory syndrome coronavirus‐2 (SARS‐COV‐2) and it has infected and killed millions of people across the globe.ObjectiveIn the absence or inadequate provision of therapeutic treatments of COVID‐19 and the limited convenience of diagnostic techniques, there is a necessity for some alternate spontaneous screening systems that can easily be used by the physicians to rapidly recognize and isolate the infected patients to circumvent onward surge. A chest X‐ray (CXR) image can effortlessly be used as a substitute modality to diagnose the COVID‐19.MethodIn this study, we present an automatic COVID‐19 diagnostic and severity prediction system (COVIDX) that uses deep feature maps of CXR images along with classical machine learning algorithms to identify COVID‐19 and forecast its severity. The proposed system uses a three‐phase classification approach (healthy vs unhealthy, COVID‐19 vs pneumonia, and COVID‐19 severity) using different conventional supervised classification algorithms.ResultsWe evaluated COVIDX through 10‐fold cross‐validation, by using an external validation dataset, and also in a real setting by involving an experienced radiologist. In all the adopted evaluation settings, COVIDX showed strong generalization power and outperforms all the prevailing state‐of‐the‐art methods designed for this purpose.ConclusionsOur proposed method (COVIDX), with vivid performance in COVID‐19 diagnosis and its severity prediction, can be used as an aiding tool for clinical physicians and radiologists in the diagnosis and follow‐up studies of COVID‐19 infected patients.AvailabilityWe made COVIDX easily accessible through a cloud‐based webserver and python code available at the site of google and the website of Github.
La escritura autógrafa de Schiller y su pensamiento entre 1792 y 1794
Authors: Salmerón Infante Miguel 
Published: December 2021

Este artículo intenta estudiar el pensamiento de Friedrich Schiller entre 1792 y 1794 a través de su escritura autógrafa. Para ello nos hemos servido de textos manuscritos del autor digitalizados por el Goethe- und Schiller-Archiv de Weimar. Examinando las tachaduras, las correcciones y los añadidos de la escritura intentamos aproximarnos al pensamiento del autor durante el citado periodo. Este es un momento decisivo en la evolución de Schiller. En él ya están bien asentados los conceptos kantianos, tal y como demuestra lo resuelto de su escritura sobre filosofía práctica y estética. Sin embargo, la escritura sobre los géneros literarios, más sometida a corrección revela un proceso de cambio. Estas diferencias en la escritura las interpretamos como el intento de Schiller de hacer un compendio de la influencia que ejerció en él la filosofía de Kant y el comienzo de una fructífera relación intelectual con Goethe.
La escritura literaria en los desfiladeros de la locura y la muerte como trabajo de insurgencia ante el poder, en “Don Quijote de la Mancha” y poemas de Leopoldo Panero
Authors: Arley Fonseca Mauricio 
Published: December 2021

El estudio primario se dirige sobre fragmentos de los capítulos XI, XII, XIV y XV de Don Quijote de la Mancha, y otra selección de textos de Leopoldo Panero.
Panero permaneció recluido voluntariamente en un psiquiátrico por más de veinte años; su condición nos recuerda la cárcel del nacimiento de las primeras líneas imaginadas de don Quijote. Psiquiátrico y cárcel son matrices de escritura con un rasgo común: la batalla.
La locura y la muerte se convierten en actos insurgentes contra los regímenes de control, pero la escritura de ficción es un fiel escudero que juega con el lenguaje y crea nuevos significados para representar mundos llenos de gérmenes vitales.
Madrasah Reposition in Building Community Trust in Covid-19 Era Disruption
Authors: Salim Ahmad , Mustakim Muh 
Published: December 2021

The advancement of information systems is an opportunity and a challenge as well as for Islamic educational institutions. One of them is a madrasah. If madrasah does not respond appropriately and wisely to this progress, madrasah will be left behind and even abandoned. Thus, in simple terms the era of "disruption" has been described by many recent scientists. In addition, the Covid-19 pandemic has implications for human life, including education. Online learning is a necessity. How has madrasah responded toward two major phenomena in the past of year. This study used a qualitative method with a case study approach. The primary data sources came from the research locus, namely MI Maarif Kokap and MTsN 4 Kulon Progo. Data collection techniques are carried out through interviews, documentation and interviews. Meanwhile, data analysis adopted a triangulation system. The results of the study describe that the two madrasahs carried out five strategic steps in building community trust, namely (1) following the dynamics of the community, (2) making learning innovations, (3) involving the surrounding community, (4) assigning offline learning under certain conditions and (5) home visit activity. These findings show that in building public trust during the pandemic and disruption era, madrasahs need to be open to existing technological developments, follow community dynamics and strengthen relationships with stakeholders.
Investigating Students’ Academic Stress on the Transition to Online Learning During the Covid-19 Pandemic
Authors: Rosdialena Rosdialena , Trinova Zulvia , Dewita Erna , Deswila Nurhamsi , Maiseptian Fadil 
Published: December 2021

This research is based on the situation of students at the State Islamic University Imam Bonjol Padang that were stressed due to the changing of learning process into online learning during the pandemic of covid-19.The study aims to describe students state based on physical response, emotion, and behaviour. Quantitative method with descriptive approach were used. The objects of the research were chosen based on Random sampling. The instrument used in the research were questionnaire based on Likert. The research found that the level of academic stress based on physical response was high at 68 %, while in emotional response was 70 % and 65 % based on behaviour. The result of the research can be used as data to improve the quality and innovation of teaching and learning during the pandemic to avoid greater issues.
Service Innovation for Route Permits and Public Transport Operations Permits through Si Pintar Solo at the Surakarta City Department of Transportation
Authors: Safitri Nina Septiani , Setyowati Kristina 
Published: December 2021

Innovation is one way to restructure public services that are integrated with information technology. Starting from the existence of public transportation in the city of Surakarta that is no longer extending due to the revitalization of public transportation, the lack of network and route permits optimization and manual public transport permit services seem convoluted, slow and take a lot of time. The Surakarta City Department of Transportation created ‘Si Pintar Solo’ innovation, which is the the Solo Route and Operation Licensing Information System. This study aims to identify and understand the implementation of the Si Pintar Solo innovation by using the innovation theory according to Rogers (2003). This is a descriptive qualitative research, with primary data, such as interviews and secondary data from related documents. The sample selected by purposive sampling. The data validity used source triangulation. The data analyzed using interactive analysis. The results showed that the implementation of the Si Pintar Solo innovation described in each of the innovation attribute criteria, such as simplifying and accelerating services because it is supported by adequate facilities and infrastructure, according to community needs. Licensing is conducted online which does not require coming to the Surakarta City Department of Transportation office and is integrated with the e-Uji service. In addition, it could monitor the licensing process and the result of licensing data is stored in the database. However, there are obstacles, such as signal limitedness and the users’ quandary about innovations involving technology.
Defining patterns in the dynamic load and strength of the bearing structure of a covered freight car with a filler in the girder beam
Authors: Panchenko Sergii , Fomin Oleksij , Vatulia Glib , Lovska Alyona , Bahrov Oleksandr , Fedosov-Nikonov Dmytro , Rybin Andrij 
Published: December 2021

This paper reports a study into determining the dynamic load and strength of the bearing structure of a covered freight car under operational modes. A feature of the freight car's bearing structure is that the girder beam has a closed cross-section. To reduce the dynamic load of the frame, the girder beam is filled with a material with viscoelastic properties. Such a solution could contribute to the transformation of the kinetic energy of impact (due to jerk, stretching, compression) into work of viscoelastic friction forces, and, consequently, to reducing the load on the bearing structure.
To substantiate the proposed improvement, the dynamic load on the bearing structure of a covered freight car was mathematically modeled. The calculation was performed for the case of joint impacts at shunting. The study was carried out in a flat coordinate system. It was established that the maximum accelerations acting on the bearing structure of a covered freight car were about 37 m/s2. The calculated acceleration value is 3.2 % lower than that obtained for the bearing structure of a covered freight car without filler.
The results of calculating the strength of the load-bearing structure of a covered freight car are given. In this case, a finite-element method was applied. The maximum equivalent stresses occur in the zones of interaction between the girder beam and the pivot beams, and amount to 319.5 MPa, which is 8 % lower than permissible. The calculation was also performed regarding other operational modes of loading the freight car's bearing structure.
The model of the dynamic load on the bearing structure of a covered freight car was verified according to the F-criterion.
The research reported here could contribute to designing innovative rolling stock structures, thereby improving the efficiency of their operation.
Numerical investigation on crack analysis of H13 fixed die and structural analysis of moving die with two different materials
Authors: Abdulhadi Hassan Abdurssoul 
Published: December 2021

Die casting is forcing molten metal into a mould with high pressure. Die casting has two dies namely moving die and fixed die where the moving one will move over the fixed die. Die casting is majorly used for high-volume production. This paper focused on the physical phenomenon of die casting for two dies (moving die and fixed die) using two different alloy materials with variable material chemical compositions.
The numerical analysis is carried out for the die casting process to determine the crack formation zone by temperature distribution and structural analysis by stress-strain relationship. The numerical analysis is carried out for both the dies. The fixed die is analyzed with an H13 tool steel material with two moving die materials as aluminum alloy (A356) and magnesium alloy (AZ91D). Both the dies (fixed and moving) were designed by using design software and meshing is carried out followed by analysis using the analysis software. The physical parameter for the dies is applied that is temperature distribution is carried out by applying a temperature of 850 °C and 650 °C over the fixed die for aluminum and magnesium alloy, respectively. Structural analysis is carried out for the moving die with a load of 1,000 N for both aluminum and magnesium alloys with 1000 number of iterations. The results from the numerical analysis are derived and analyzed for both temperature distribution and structural analysis. The crack formation zone is found out by means of temperature gradient and the stress-strain relationship is found out by means of structural analysis. From the results, it was concluded that the crack zone is obtained at 1.22E-10 °C/mm and 6.856E-14 °C/mm of thermal gradient and structural analysis in terms of maximum stress of 446.94 MPa and 448.52 MPa for aluminum and magnesium alloys, respectively.
Improving the unit for melting cheese masses
Authors: Bondar Mariana , Skoromna Oksana , Ponomarenko Nataliia , Tesliuk Hennadii , Honcharova Iryna , Nedosiekova Nataliia , Shaferivskyi Bohdan , Zakharchenko Ruslan 
Published: December 2021

This paper reports the improved model of the unit for melting cheese masses. The device differs in the technique of heat supply to working tanks through the replacement of a steam jacket with heating by a flexible film resistive electric heater of radiative type (FFREhRT). The heat exchange surface of the working container was increased through heating the mixing device by FFREhRT. In addition, the unit is distinguished by utilizing secondary thermal energy of melting cheese masses (35...95 °C) by converting it with Peltier elements into a low-voltage power supply to autonomous fans (3.5...12 W) in order to cool the control unit. Such a solution would improve the efficiency of the proposed structure, which is explained by reducing the dimensional and weight parameters of the cheese melting unit by replacing the steam heating technique with an electric one.
A decrease in the time to enter a stationary mode (85 °C) when melting cheese masses was experimentally confirmed: for the bowl of the examined unit ‒ 575 s, compared to the analog ‒ 725 s. That confirms the reduction in the time to enter a stationary mode by 21 % compared to the base unit B6-OPE-400.
The estimation has established a 1.2-time decrease in the main indicator of resource efficiency of the specific energy consumption for heating the volume of a unit of product in the improved plant for melting cheese masses – 3,037.2 kJ/kg, compared to the base B6-OPE-400 – 3,672.5 kJ/kg. The results confirm an increase in resource efficiency that is achieved by the elimination of steam heat networks; the increased heat exchange surface of working bowls by heating the stirrer with the help of FFREhRT. The heat transfer that employs FFREhRT simplifies the operational indicators of the temperature stabilization system in the bowl of the cheese mass melting unit. The results reported here may prove useful when designing thermal equipment with electric heating while using secondary thermal energy.
Voltage stabilization of a controlled autonomous magnetoelectric generator with a magnetic shunt and permanent magnet excitation
Authors: Chumack Vadim , Bazenov Volodymyr , Tymoshchuk Oksana , Kovalenko Mykhailo , Tsyvinskyi Serhii , Kovalenko Iryna , Tkachuk Ihor 
Published: December 2021

The paper presents the results of testing and research of the characteristics of a controlled autonomous magnetoelectric synchronous generator with a magnetic shunt. Structurally, the studied generator is a modified asynchronous machine in which the rotor is made with permanent magnets and an additional system in the form of a magnetic shunt. By adjusting the winding current of the magnetic shunt, the output voltage of the generator is regulated. The following characteristics were investigated: the no-load characteristic during operation with permanent magnets and when the winding current of the magnetic shunt changes with forward and reverse polarity. Also, the external characteristic for active and active-inductive loads; the control characteristic when the load current changes at a constant generator voltage.
Analysis of the obtained characteristics makes it possible to determine the limits of regulation of the external characteristic, which is ≈40 % relative to the main magnetic flux. The obtained regulation depth allows maintaining the stability of the external characteristic for power factors not exceeding 0.9, which is the usual passport value for autonomous power plants based on synchronous generators. Comparison of the data of research conducted on the experimental setup shows sufficient convergence for engineering and practical tasks. The maximum quantitative difference is 9.3 %, which suggests the adequacy of the previously developed mathematical model. The control characteristic, constructed experimentally at constant generator voltage, is the control law of the magnetic shunt winding for the studied generator.
The investigated version of a synchronous generator with a magnetic shunt should be used for autonomous power plants, renewable energy systems, and autonomous power supply systems.
Development of mechanical coupling and exciter system in synchronous generators
Authors: Damij Raad Lafta 
Published: December 2021

Power is generated in a variety of ways, including renewable energy, nuclear power, and burning of fossil fuels. The majority of our power is currently generated by burning fossil fuels, mostly natural gas and coal, to spin turbines attached to an electromagnetic generator. The main advantage of AC generation is that the voltage levels can be altered up and down with transformers, allowing electricity to be sent across long distances to the loads that demand it. The excitation system demand for large synchronous generators with a few hundred-megawatt ratings becomes very enormous. The challenge of transmitting such a big amount of power through high-speed sliding contacts becomes daunting. Mechanical coupling with exciter for synchronous generators is essential to mitigate such problems as the corrected output is linked directly to the field winding. This paper aims to develop a simulation of a 3-phase diesel engine-based 2 MVA/400 V synchronous generator with mechanical coupling and an exciter system. The developed simulation of the synchronous machine is set to deliver 25 % of its rating value (500 kW) till the time of 3 sec. Then, additional power of 1 MW is switched at t=3 sec via a 3-phase circuit breaker. The dynamic response of field current and field voltage of the simulation shows reasonable step performance as the steady-state time is less than 3 sec. The control of the excitation system allows the generator to maintain voltage, control reactive power flow, and assist in maintaining power system stability. The simulation was accurate when measuring the voltage and current under these changes. This analysis can help to investigate further integration with renewable energy sources.
Determining the features of oscillations in prestressed pipelines
Authors: Suleimenov Ulanbator , Zhangabay Nurlan , Utelbayeva Akmaral , Ibrahim Mohamad Nasir Mohamad , Moldagaliyev Arman , Abshenov Khassen , Buganova Svetlana , Daurbekova Saltanat , Ibragimova Zaure , Dosmakanbetova Aibarsha 
Published: December 2021

This paper considers the structural solution for a main above-ground pipeline with a pre-stressed winding, which makes it possible to improve the efficiency of operation and reduce material consumption. The results from studying experimentally the features in the operation of prestressed pipelines under static operating loads are given. It is shown that the radial movements of the wall of a pre-stressed pipeline are constrained by the strained winding, which prevents its deformation. It was revealed that increasing the tension force of the winding wire reduces circular stresses in the pipeline wall by 1.3...1.6 times and increases meridional ones by 1.2...1.4 times.
The experimental study into the models of prestressed pipelines with free vertical and horizontal oscillations has established the dependence of frequency characteristics on the operating conditions and pre-stress parameters. It was found that the envelope amplitude on the oscillogram of free attenuated oscillations takes the shape of an exponent, which indicates the damping effect of the pre-stress. Analysis of the change in the dynamic characteristics of the models depending on the pre-stress force has revealed that the frequencies of free oscillations increase by 1.5÷1.6 times while the oscillation decrement decreases by 1.2÷1.25 times.
This paper reports the results of studying the influence of pre-stress parameters on the stressed-strained state of the pipeline model under forced horizontal and vertical oscillations.
It is shown that the diagrams of circular dynamic stresses and deformations in the models of a prestressed pipeline are smoother compared to similar characteristics of a conventional pipeline tested at the same experimental parameters.
The study results have made it possible to quantify the features in the operation of a pre-stressed pipeline under static and dynamic influences, taking into consideration the pre-stress parameters and operating conditions.