bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fully automated glioma tumour segmentation using anatomical symmetry plane detection in multimodal brain MRI
Authors: Barzegar Zeynab , Jamzad Mansour 
Published: March 2021

AbstractAutomatic brain abnormality detection is a major challenge in medical image processing. Manual lesion delineation techniques are susceptible to subjective errors, and therefore, computer aided preliminary screening of a lesion is necessary. This study introduces an efficient and automated algorithm based on the symmetry of the brain structures in the two hemispheres for brain tumour segmentation using multimodal brain magnetic resonoce imaging. Symmetry is a vital clue for determining intensity‐based lesion difference in the two hemispheres of brain. A reliable method is proposed for extracting the cancerous region in order to improve the speed and accuracy of brain tumour segmentation. First, a symmetry plane is detected and then through features extracted from both sides of the brain, a similarity measure for comparing the hemisphere is defined. The cancerous region is extracted using similarity measurement, and the accuracy is improved using postprocessing operation. This algorithm is evaluated against the BRATS datasets including high‐ and low‐grade glioma brain tumours. The performance indices are calculated and comparative analysis is implemented as well. Experimental results demonstrate accuracy close to manual lesion demarcation with performance indices.
A novel deadbeat predictive current control of permanent magnet synchronous motor based on oversampling scheme
Authors: Wang Zhiqiang , Xie Saifei , Jin Xuefeng , Shi Tingna , Yang Mingbo 
Published: March 2021

AbstractWhen the speed of permanent magnet motor is relatively high, the fundamental frequency of stator voltage and current will rise. However, due to the limitation of switching frequency of power electronic devices, the switching times of power devices will be greatly reduced in a fundamental cycle of stator voltage. For the traditional control method with constant switching frequency mode, the control algorithm is executed only once in a carrier wave cycle, which will result in a low control frequency operating condition for the PMSM control system. At this time, the dynamic and steady‐state control performance of stator current will be decreased. In response to above problem, this paper proposed a deadbeat predictive current control method based on oversampling scheme, which the core algorithm of current loop operated four times and updated the PWM duty twice in one switching cycle. The number of control times of the proposed method is greater than that of the conventional method when the conventional deadbeat method and the proposed method adopt the same switching cycle. Therefore, the control method does not increase the switching frequency of power devices, but improves the dynamic and stable performance of the system, especially under the high‐speed condition.
Speed fluctuation suppression of PMSM using active disturbance rejection and feedback compensation control
Authors: Xie Fang , Hong Wenjie , Qiu Chenming 
Published: March 2021

AbstractThis study proposes the active disturbance rejection control (ADRC) and feedback compensation control method that can solve the speed fluctuation problem of permanent magnet synchronous motors resulting from parameter variation and load disturbance. First, the influencing factors of speed fluctuation are analysed on the basis of a speed analytical model, and a motor robust control system is established. Second, the ADRC method is introduced to establish current controllers in accordance with the state equation for voltage output. The shuffled frog leaping algorithm is also used to automatically optimize the adjustable parameters of the active disturbance rejection controller and to improve the system robustness when the parameters vary. Third, a feedback compensation control method based on the electromagnetic torque observer is introduced to compensate for the q‐axis current in real time. The speed fluctuation caused by load disturbance is also suppressed. Lastly, the validity and feasibility of the proposed method are verified through experiments.
Review of methodologies used for detection of magnetising inrush and fault conditions in power transformer
Authors: Raichura Maulik , Chothani Nilesh , Patel Dharmesh 
Published: March 2021

AbstractReliable and dedicated protection of the transformer is the main requirement in the power system due to the supervision of a highly expensive equipment transformer. Non‐linear characteristics of the transformer give mysterious behaviour for the period of inrush and Current transformer saturation conditions. As a stagnant and electro‐magnetic device, a transformer is mainly affected by self‐inrush. The saturation of the core itself is a very critical situation that becomes a hindrance for fault discrimination. This article involves the elaboration of the effect of inrush on transformer operation, past research practices for the discrimination of inrush with the faulty condition, and a definite method to recognise inrush and fault condition of the transformer. More than 50 reputed journal articles, various book chapters, and books with research thesis thoroughly studied to review the inrush and fault discrimination conditions. A comparative analysis is prepared to suggest the identification of transformer abnormalities. Moreover, a total harmonics distortion (THD)‐based solution proposed for discrimination of the inrush condition from fault and other abnormal conditions using the short time Fourier transform technique. Hardware setup for 2 kVA transformer developed in the laboratory to study different inrush phenomena and altered fault conditions. Simulation and hardware results show various effects of inrush and fault with individual harmonic and THD‐based analysis. The collection of real‐time data is further used based on laboratory hardware setup to enhance real‐time protection schemes for power transformers.
Review of interface tailoring techniques and applications to improve insulation performance
Authors: Zhu Mingxiao , Xue Jianyi , Wei Yanhui , Li Guochang , Zhang Guanjun 
Published: March 2021

AbstractInterfaces between different materials, for instance, electrode–dielectrics and vacuum/air/SF6‐insulators and oilpaper, are universal in high‐voltage insulation systems. Targeted tailoring of the interfacial properties, e.g. chemical structures, micro‐/nanoscale morphology, the charge injection barrier, trap states, and surface conductivity, is thought to be an effective approach to improve insulation properties such as breakdown and flashover strength, corona/tracking resistance, and wettability. In this article, the authors review recent progress in interface tailoring methods and their application to improve various insulation properties. The potential application scenarios of interface tailoring in different facilities are first summarised, and the desired insulation properties of various applications are highlighted. Interface tailoring methods are classified as physical/chemical surface modification and surface coating (inorganic, organic and composite), and the features of different techniques are described in detail. The structure–property relationships between interfacial states and various microscopic parameters such as charge injection barrier, trap distribution and surface conductivity are discussed together with the tailoring mechanisms for different insulation properties. Finally, the future development prospects of interface tailoring methods and their applications, e.g. multifunctional coating and stimuli–response smart coating, are presented.
Intrinsic synchrosqueezing analysis on micro‐Doppler features for small unmanned aerial vehicles identification with dual‐channel radar
Authors: Zhao Yichao , Su Yi 
Published: March 2021

AbstractThe micro‐Doppler (m‐D) effect depends on the rotation of rotor blades in addition to the translation of the platform. Thus it is a characteristic for identifying small unmanned aerial vehicles (UAVs). However, compared with the Doppler signal induced by the translation of the platform, the m‐D signal is weak. In this article, a highly localised data‐association method, intrinsic synchrosqueezing analysis (ISA), is proposed for estimating m‐D characteristics from the returned signal of small UAVs with a dual‐channel radar. Employing synchrosqueezing transform on intrinsic mode functions derived from noise‐assisted multivariate empirical mode decomposition, the proposed ISA method separates the Doppler signal and enables denoising and sharpening time‐frequency representation of the m‐D signal. Simulation results confirm the theoretical analysis, showing the feasibility of estimating m‐D features in a noisy environment. Applications on field data illustrate brighter prospects for identifying small UAVs.
Magnetic field penetration through a circular aperture in a perfectly conducting plate excited by a coaxial loop
Authors: Lovat Giampiero , Burghignoli Paolo , Araneo Rodolfo , Celozzi Salvatore 
Published: March 2021

AbstractThe transmission of an electromagnetic field produced by a current loop of finite radius through a coaxial circular aperture in a perfectly conducting plate is evaluated through a rapidly convergent formulation in an exact form. By applying the equivalence principle, the problem is first formulated in the Hankel transform domain, obtaining a set of dual integral equations in which the equivalent surface magnetic current density defined on the aperture is not known. The set of dual integral equations is regularised in a second‐kind Fredholm integral equation by applying the Abel integral‐transform technique. The solution is achieved by expanding the unknown in a set of orthogonal basis functions that correctly reproduce the behaviour of the equivalent magnetic current at the edge of the aperture. Finally, under particular assumptions, a low‐frequency solution is extracted in a closed form. Numerical results are reported to validate the accuracy and efficiency of the proposed formulations.
On the spectral nature of entanglement
Authors: Mastriani Mario 
Published: March 2021

AbstractThis study establishes, for the first time in literature, that quantum entanglement, as well as the most important protocol derived from it, that is, quantum teleportation, completely rest on the Quantum Fourier Transform. This highlights the spectral nature of both protocols with important consequences on quantum computing, quantum communications, and quantum cryptography, with a particular emphasis on quantum Internet.
Intermodal Brillouin scattering in solid-core photonic crystal fibers
Authors: Jarschel Paulo F. , Lamilla Erick , Espinel Yovanny A. V. , Aldaya Ivan , Pita Julian L. , Gil-Molina Andres , Wiederhecker Gustavo S. , Dainese Paulo 
Published: March 2021

We investigate intermodal forward Brillouin scattering in a solid-core photonic crystal fiber (PCF), demonstrating efficient power conversion between the HE11 and HE21 modes, with a maximum gain coefficient of 21.4 W−1 km−1. By exploring mechanical modes of different symmetries, we observe both polarization-dependent and polarization-independent intermodal Brillouin interaction. Finally, we discuss the role of squeeze film air damping and leakage mechanisms, ultimately critical to the engineering of PCF structures with enhanced interaction between high-order optical modes through flexural mechanical modes.
Semitendinosus and biceps femoris long head active stiffness response until failure in professional footballers with vs. without previous hamstring injury
Authors: Freitas Sandro R. , Mendes Bruno , Firmino Telmo , Correia José Pedro , Witvrouw Erik E. M. C. , Oliveira Raúl , Vaz João R. 
Published: March 2021

ABSTRACTThis study sought to examine the active stiffness of semitendinosus (ST) and biceps femoris long head (BFlh) during a knee flexor isometric contraction at 20% of maximal voluntary isometric contraction until failure in elite footballers (n = 50, age: 22.3 ± 5.3 years; height: 1.82 ± 0.08 m; body mass: 74.7 ± 9.0 kg). Active stiffness was assessed using ultrasound‐based shear wave elastography by means of shear modulus quantification. Comparisons were performed between limbs with (n = 11) vs. without (n = 89) previous hamstring injury. A similar time until failure in the knee flexor fatigue task was observed between groups (p = .401). At the start of the task, lower limbs with previous hamstring injury showed a lower BFlh active stiffness (31.0.1 ± 10.4 kPa, p = .023) and BFlh/ST active stiffness ratio (0.50 ± 0.29), and no differences for ST (72.8 ± 26.8 kPa, p = .221) compared to lower limbs without previous hamstring injuries (BFlh: 38.0 ± 9.6 kPa; ST: 64.0 ± 18.4 kPa; BFlh/ST: 0.65 ± 0.27). During the task, the ST active stiffness in both groups decreased from 80% of task time (p = .032), in the absence of changes in BFlh active stiffness (p = .534), resulting in an increase in BFlh/ST active stiffness from 80% of task time (p = .029). No differences between limbs were observed during the fatigue task for all parameters (p > .099). Future research is warranted to verify if the differences found represent an increased risk of hamstring injury.

Highlights
The hamstring's active stiffness response to a fatigue protocol in soccer athletes with a history of injury is unknown.
Athletes with previous injury showed less active stiffness in the biceps femoris long head.
Similar response to fatigue was observed between athletes with and without hamstring injury history.
Decoherence effects in non-classicality tests of gravity
Authors: Rijavec Simone , Carlesso Matteo , Bassi Angelo , Vedral Vlatko , Marletto Chiara 
Published: March 2021

Abstract
The experimental observation of a clear quantum signature of gravity is believed to be out of the grasp of current technology. However, several recent promising proposals to test the possible existence of non-classical features of gravity seem to be accessible by the state-of-art table-top experiments. Among them, some aim at measuring the gravitationally induced entanglement between two masses which would be a distinct non-classical signature of gravity. We explicitly study, in two of these proposals, the effects of decoherence on the system’s dynamics by monitoring the corresponding degree of entanglement. We identify the required experimental conditions necessary to perform successfully the experiments. In parallel, we account also for the possible effects of the continuous spontaneous localization (CSL) model, which is the most known among the models of spontaneous wavefunction collapse. We find that any value of the parameters of the CSL model would completely hinder the generation of gravitationally induced entanglement.
Impact of neutron irradiation on hardening of baseline and advanced tungsten grades and its link to initial microstructure
Authors: Yin Chao , Terentyev Dmitry , Dubinko Andrii , Zhang Tao , Wirtz Marius , Antusch Steffen , Petrov Roumen H. , Pardoen Thomas 
Published: March 2021

Abstract
Six tungsten grades were irradiated in the Belgian material test reactor (BR2) and characterized by Vickers hardness tests in order to investigate the irradiation-induced hardening. These tungsten grades included: Plansee (Austria) ITER specification tungsten, ALMT (Japan) ITER specification tungsten, two products from KIT (Germany) produced by powder injection molding (PIM) and strengthened by 1% TiC and 2% Y2O3 dispersed particles, and rolled tungsten strengthened by 0.5% ZrC from ISSP (China). The materials were irradiated face-to-face at three temperatures equal to 600 °C, 1000 °C, and 1200 °C to the dose of ∼1 dpa. The Vickers hardness tests under 200 gf (HV0.2) were performed at room temperature. The Vickers hardness increases as the irradiation temperature increases from 600 to 1000 °C for all materials, except for the ZrC-reinforced tungsten, for which the increase of hardness does not depend on irradiation temperature. The irradiation-induced hardness decreases after irradiation at 1200 °C. This is a result of defect annealing enhanced by thermally activated diffusion. However, even at 1200 °C, the impact of neutron irradiation on the hardness increase remains significant; the hardness increases by ∼30 to 60% compared to the non-irradiated value. In the case of TiC-strengthened material, the irradiation hardening progressively raises with irradiation temperature, which cannot be explained by the accumulation of neutron irradiation defects solely.
Diagnosis misconceptions of junior high school in Lamongan on the heat concept using the three-tier test
Authors: Haryono H E , Aini K N 
Published: March 2021

Abstract
Misunderstanding is one of the causes of junior high school students in the city of Lamongan learning difficulties, especially studying physics material. The aim of this study was to investigate whether the three-tier test able to identify student misconceptions. Based on the research objectives to be achieved, this research is a descriptive study using descriptive qualitative methods in explaining the research results. The technique of collecting data through tests is by using a Three-Tier Test diagnostic instrument and open interview. Diagnostic results data are expressed in terms of percentage of the students’ conception categories. The sample of this research is the students who have received the Heat material, seventh graders. The subjects of this study were grade VII students totaling 150 students with details of 60 male students and 90 female students with age around 12 to 13 years old. Besides using written tests, interviews were conducted on several students to verify the results of the three-tier test. From the analysis of three-tier test diagnostic data students showed that from 47% including the criteria to master the concept, while the remaining 38% experienced misconceptions, 5% guess or not believe in the answers, and 10% don’t know the concept. Conclusions of this study is the three-tier test that has been developed on Heat topic is able to identify misconceptions students quickly and accurately. Therefore, a three-level diagnostic test tool that has been developed to diagnose students ‘misconceptions about temperature and heat materials can identify students’ misconceptions quickly and accurately.
The development of device learning based on TPACK (technological pedagogical content knowledge) in the form of hypercontent modules in electronics courses
Authors: Rufaida S , Nurfadilah  
Published: March 2021

Abstract
This study aims to develop a device learning based on TPACK (Technological Pedagogical Content Knowledge) in the form of hypercontent modules in electronics courses that combine technological, pedagogical, and material content knowledge by using QR code as a learning navigation tool so it acts as open resources for learning. This device sustains the 21st century system and independent learning, because students can begin to learn the subject needed with non-linearly and facilitate learning styles by providing variety of learning resources such as site addresses, journal texts, videos, audio, and images that can be accessed with QR code reader so learning feels contextual and able to direct students to think creatively in learning. Research and development carried out using the Borg and Gall models with the step of collecting information, do the planning, developing product formations, testing, revising, disseminating, and implementing the product. This research shows that device learning based on TPACK in the form of hypercontent modules is valid, practice, and effective for use in electronics courses as seen from the improvement of student learning outcomes.
Using three-tier test to diagnose students’ level of understanding
Authors: Pramesti Y S , Mahmudi H , Setyowidodo I 
Published: March 2021

Abstract
Assessment activities can help lecturer to understand the strengths and weaknesses experienced by students in learning. By implementing quality assessments and analyzing them to get information about student learning weaknesses, lecturers have a reference to make effective decisions in the learning process. Ability to understand is very important to solve physics problem. Geometric optics is a concept that occur in our daily life. In contrary, it doesn’t ensure students have correct concept about geometric optics. The purpose of this study is to diagnose students’ level of understanding in geometric optics concept. This study used mixed method design. The sample used in this study was Mechanical Engineering students who took Engineering Physics courses. Based on test result data using paired sample t-test, the average score was obtained from 39.08 to 75.76 (p <0.01). The results of data analysis from the three-tier test diagnostic instrument showed that there are 4 level of students’ understanding such as understand, guess, misconception, and don’t understand the concept. This study revealed the students’ difficulties such as students were not been able to analyze terms and conditions of

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The evaluation on the use of e-learning media to improve HOTS through authentic and holistic assessments
Authors: Yusuf I , Widyaningsih S W , Prasetyo Z K , Istiyono E 
Published: March 2021

AbstractThis study aims to improve students’ Higher Order Thinking Skills (HOTS) through the use of e-learning. The type of research used is Participatory Action Research (PAR) which refers to the Davison, Martinsons & Kock model. The subjects used were 11 students majoring in Department of Physics Education at the Universitas Papua who programmed basic physics courses with two lecturers as instructors. The students consisted of 6 female and 5 male, with an average age of 19 years. The research instruments are in the form of HOTS questions and online questionnaires about the effectivity and practicality of using e-learning. Students’ HOTS assessment were done authentically and holistically by looking at the various effects of optimizing the use of e-learning that can improve student HOTS. The results showed that the use of e-learning media consisting of various supporting devices such as modules, animation, simulation, multimedia, and online virtual laboratories could increase students HOTS. Students give agreeing responses to the use of e-learning media. It can be concluded that e-learning can improve HOTS ‘ability and students agree the learning process. This study’s recommendations are the need for sufficient internet access and affordable fees, especially for students.
Development and validation of students’ achievement, ability to ask and inductive thinking instruments in the static fluid course
Authors: Halim A , Ayunda D S , Susanna  , Mustafa  , Syukri M , Irwandi  
Published: March 2021

AbstractThe purpose of this article is to discuss the results of developing several test and non-test instruments to be used as a measurement of learning outcomes, questioning skills and students’ inductive thinking skills. Development using the ADDIE model. Based on expert assessments and trials on a limited sample, 20 items were obtained for the learning outcomes instrument, 12 items for the non-test question ability and 10 items for the non-test instrument inductive thinking ability. The results of the analysis of data for the Learning Outcomes Test of Statis Fluid (LOTSF), the Questioning Ability Observation Sheet instrument (QAOS), and the Inductive Thinking Ability Observation Sheet (ITAOS) instrument obtained a validity of 0.6 and a reliability value of 0.75. Inference from this study to lecturers or teachers who teach Static Fluid concepts can follow the test development procedure offered in this article or use instruments produced from this study.