bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis and implementation of virtual impedance for fixed‐frequency control strategy in microgrid
Authors: Qian Haiya , Xu Qingshan , Xia Yuanxing , Zhao Jun , Du Pengwei
Published: March 2021

Classic droop control ensures the synchronization of distributed generation (DG) units inside a microgrid without requiring any deployment of communication links, however it causes unwanted frequency fluctuations and degrades system dynamics. Angle droop control and control have been developed as two major global positioning system (GPS)‐based control methods, both of which realize a fixed‐frequency operation of the microgrid through synchronizing DG units with GPS timing technology and brings improvement to the dynamic response of the overall system. This paper reveals the similarities and the correlations between these two methods that they can both be regarded as different forms of virtual impedance control. A novel adaptive virtual impedance control method is proposed accordingly to generalize GPS‐based control strategies into a unified control frame. An impedance and inner controller design approach considering both stability constraints and power quality requirements based on the small‐signal model of GPS‐based microgrids is presented for practical implementation. An adaptive transient resistance concept is adopted to enhance the system stability during large disturbances and grid faults. Case studies are presented to validate the system performance and fault ride‐through abilities of the proposed control scheme.
Occluded pedestrian detection combined with semantic features
Authors: Ruan Binjie , Zhang Chongyang
Published: March 2021

The task of pedestrian detection is to identify the location and size of pedestrians in images or videos. However, occlusions are very common in real‐life scenarios, which make pedestrian detection more difficult. In order to solve the occlusion problem in pedestrian detection, a semantic feature enhancement module to acquire more informative and richer semantic features is proposed. The detector enhances semantic features by fusing feature maps of different layers, and detects pedestrians based on their locations and scales. The Experiments performed on Caltech and CityPersons datasets show that the algorithm achieves superior performance for detecting occluded pedestrians, especially heavily occluded ones. 30.6% and 47.9% log‐average missing rates are achieved in the heavily occluded subsets of Caltech and Cityperons, respectively. Moreover, this method is robust to the detection of heavily occluded pedestrians, and the module can be easily used by other detection frameworks.
Flexible circularly polarized antenna with axial ratio bandwidth enhancement for off‐body communications
Authors: Yang Hong Cai , Liu Xiong Ying , Fan Yi , Tentzeris Manos M.
Published: March 2021

A flexible circularly polarized (CP) wearable antenna is proposed for a wireless body area network at the 5.8‐GHz industrial, scientific, and medical band. The proposed antenna is made of flexible polyimide and foam material. The CP radiation is enabled by loading two pairs of shorting pins on a rectangular patch antenna. The 3‐dB axial ratio (AR) bandwidth is doubled by adding two inverted L‐shaped parasitic stubs on both sides of the antenna. For validation, the antenna with the dimensions of 0.68λ0 × 0.68λ0 × 0.044λ0 was fabricated and measured in various scenarios with an impedance bandwidth of 6.6% (5.67–6.05 GHz), an AR bandwidth of 3.85% (5.730–5.955 GHz), and a peak gain of 7.2 dBi. The measured radiation in the off‐body direction is achieved with a half‐power beamwidth of 65° and a 3‐dB AR beamwidth of 84°. With the specified input power of 100 mW, the specific absorption rates are 0.613 and 0.294 W/kg in 1‐g and 10‐g average tissues. Moreover, through analysing the link budget a reliable communication can be guaranteed within 20 m in indoor line‐of‐sight environments.
Angular characteristics of multipath propagation in an indoor industrial environment
Authors: Bamba Aliou , Tanghe Emmeric , Kamagaté Aladji , Laly Pierre , Challita Frédéric , Konaté Adama , Joseph Wout , Liénard Martine , Gaillot Davy P.
Published: March 2021

The characteristics of multipath components (MPCs) are addressed in an industrial environment at 1.3 GHz by means of measurements with a multidimensional channel sounder. The maximum likelihood estimator, RiMAX, is used to determine the MPCs parameters and takes into account the diffuse scattering. Both line‐of‐sight (LOS) and obstructed LOS (OLOS) scenarios have been considered, along with the four polarization states. We found that the environment is very rich in multipath, that is on average, about 120 (resp. 70) MPCs in LOS (resp. OLOS) scenario due to the presence of several metallic reflectors. The azimuthal angle implies clustering of the MPCs, and therefore, the estimated MPCs are grouped in clusters using the K‐powers‐means algorithm based on the multipath component distance. In general, one to four clusters are determined with three clusters occurring with the highest probability, regardless of the scenario. Next, the intra‐cluster parameters have been determined, and we show that the root‐mean‐square (rms) delay spread and rms angular spread follow a gamma distribution, regardless of the polarization. The MPC characteristics agree with the results in the literature and can be valuable when deploying a wireless sensor network in industrial environments.
Compact beam‐switchable antenna for mm‐wave 5G handheld devices
Authors: Arshad Farzana , Khan Zia Ullah , Ali Ahsan , Amin Yasar , Tenhunen Hannu
Published: March 2021

An electronically beam‐steerable antenna (BSA) is envisioned. The presented BSA is a possible solution to overthrow the limitations inherent to phased antenna arrays. The design consists of a gap coupling inset feed rectangular patch (driven element) and 3 × 1 passive parasitic patches deployed on both sides of the driven patch. Prototype having 20  × 20 mm dimensions is printed on Rogers® RT/duroid®5870. Four switches are used to load the reactive impedance on parasitic patches, which in turn, change the phases of surface current on parasitic elements and the driven element. Based on the different ON and OFF configuration of switches in parasitic array elements, the main beam is steered along with different directions. The simulated results show that the design can operate between 26.8 and 30.3 GHz a wide impedance bandwidth |S11|< −10 dB (12.5%) with a peak gain of 8.9 dBi and wide 3‐dB scanning angle that is, −37° to 156° in the azimuth plane. The exhibited performance of BSA with favourable characteristics, such as wideband, adequate gain, wide‐angle beam switching, and low profile renders the BSA a good candidate for 5G millimetre wave handheld devices. Moreover, to corroborate the performance, the design is fabricated, and experimental measurements were performed. Congruence is observed between the experimentally measured and computationally simulated results. The simulated results of spherical coverage analysis of BSA with the integration of smartphone form factor are also presented.
Switching transient‐based state of Ampere‐hour prediction of lithium‐ion, nickel‐cadmium, nickel‐metal‐hydride and lead acid batteries used in vehicles
Authors: Ray Debopoma Kar , Roy Tamal , Chattopadhyay Surajit
Published: March 2021

The state of the ampere‐hour capacity of the battery depends on the condition of materials used in it. Large reduction of capacity ends with maintenance or replacement of the battery. Modern battery materials include application of nanomaterials and nanotechnology in various stages of production. This article attempts to monitor the capacity of battery used for vehicles which are made of different types of materials using switching transients. The analytical part was done using wavelet‐based decompositions. Data sets of large number of coefficients have been developed for learning. Their statistical behaviour has been studied, and monitoring was initially carried out by some selective parameters. Then the artificial neural network‐based algorithm was developed which includes all features of statistical variation for better monitoring. Case studies have been carried out followed by comparison. The study ends with a satisfactory monitoring.
Transverse electric/magnetic switchable absorption ring modulator based on graphene
Authors: Zhou Feng , Liang Chen
Published: March 2021

We propose a transverse electric (TE)/transverse magnetic (TM) switchable absorption ring modulator based on graphene that can operate in either the TE or the TM mode. By adjusting the applied voltages onto the graphene layers in horizontal and perpendicular directions, either a TE or a TM absorption ring modulator can be configured, as has been previously reported. The simulation results show that a TE or TM modulator can be configured with a large extinction ratio and wide waveband from 1300 to 2000 nm. Specifically, the modulation bandwidth can be enlarged to over 130 GHz, which is rarely seen in conventional ring modulators. Also investigated is the possibility of extending the resonance wavelength shift to more than 5 nm by replacing the monolayer graphene structure with a quadrilayer graphene structure.
Theoretical study of hazardous carbon‐di‐oxide gas sensing using MIM structure‐based SPR sensing scheme
Authors: Srivastava Akash , Verma Alka , Prajapati Yogendra Kumar
Published: March 2021

This work mainly focussed on the sensing of the environmentally damaging gas carbon dioxide (CO2) by designing a gas sensor based on a surface plasmon resonance (SPR) principle. The proposed model is based on the metal‐insulator‐metal (MIM) model which mainly relies on metal thickness, dielectric thickness, and incident light wavelength. A comparative analysis between conventional as well as MIM‐based structure is shown in this study and it is observed that by operating at 4400 nm incident light wavelength,the MIM‐based structure shows sharp resonance curve, high resolution, minimum FWHM, and extremely high FOM. By using the modified Elden's formulae, the variation in refractive index is investigated by changing the numerical values of humidity, temperature, pressure, and CO2 content from the reference value, respectively. For each case, the sensitivity has been estimated. By using the proposed MIM‐based structure, FOM value as high as 1273.11RIU−1; at the end of this article, limit of detection (LOD) is calculated by varying the CO2 gas concentration.
Seismic constraints on the internal structure of evolved stars: From high-luminosity RGB to AGB stars
Authors: Dréau G. , Mosser B. , Lebreton Y. , Gehan C. , Kallinger T.
Published: March 2021

Context. The space-borne missions CoRoT and Kepler opened up a new opportunity for better understanding stellar evolution by probing stellar interiors with unrivalled high-precision photometric data. Kepler has observed stellar oscillation for four years, which gave access to excellent frequency resolution that enables deciphering the oscillation spectrum of evolved red giant branch and asymptotic giant branch stars.

Aims. The internal structure of stars in the upper parts of the red and asymptotic giant branches is poorly constrained, which makes the distinction between red and asymptotic giants difficult. We perform a thorough seismic analysis to address the physical conditions inside these stars and to distinguish them.

Methods. We took advantage of what we have learnt from less evolved stars. We studied the oscillation mode properties of ∼2.000 evolved giants in a model described by the asymptotic pressure-mode pattern of red giants, which includes the signature of the helium second-ionisation zone. Mode identification was performed with a maximum cross-correlation method. Then, the modes were fitted with Lorentzian functions following a maximum likelihood estimator technique.

Results. We derive a large set of seismic parameters of evolved red and asymptotic giants. We extracted the mode properties up to the degree ℓ = 3 and investigated their dependence on stellar mass, metallicity, and evolutionary status. We identify a clear difference in the signature of the helium second-ionisation zone between red and asymptotic giants. We also detect a clear shortage of the energy of ℓ = 1 modes after the core-He-burning phase. Furthermore, we note that the mode damping observed on the asymptotic giant branch is similar to that observed on the red giant branch.

Conclusions. We highlight that the signature of the helium second-ionisation zone varies with stellar evolution. This provides us with a physical basis for distinguishing red giant branch stars from asymptotic giants. Here, our investigation of stellar oscillations allows us to constrain the physical processes and the key events that occur during the advanced stages of stellar evolution, with emphasis on the ascent along the asymptotic giant branch, including the asymptotic giant branch bump.
The study of heat control on PVT modules with a new leaf-like heat exchanger
Authors: Zhang Yingbo , Shen Chao , Zhang Chunxiao , Lv Guoquan , Sun Cheng , Chwieduk Dorota
Published: March 2021

The photovoltaic/thermal (PVT) collector is an eco-friendly technology that simultaneously converts solar energy into electrical and thermal energy. However, a high solar cell temperature seriously affects the electrical efficiency of the PVT collector, which is an urgent problem that needs to be addressed. Some traditional cooling technologies for PVT collectors were previously investigated, but they were inefficient in heat collecting performance. In addition, a nonuniform solar cell temperature distribution accelerates the aging of PVT modules, and this topic has only rarely been discussed. In the present study, a new leaf-like heat exchanger based on bionics was proposed to improve heat control of the PVT collector. A three-dimensional mathematical model was developed in COMSOL and validated by comparing modeling results with experimental data already available in the literature. The effect of different operating conditions on the performance of the new PVT collector was investigated. The results of this study show that the bifurcation angle of the leaf-like heat exchanger with a symmetrical configuration between 20° and 35° was characterized by a lower and more uniform temperature distribution on solar cells in comparison with conventional heat exchangers. Moreover, the average temperature of the solar cell cooled by the new leaf-like heat exchanger decreased by 5.31 °C, and the pressure drop associated with the leaf-like heat exchanger was only half the value of the pressure drop associated with a conventional heat exchanger at a mass flow rate of 0.0314 kg/s. Finally, the total efficiency of the new PVT collector was 4.36% higher than that of the conventional PVT collector.
Why does New Zealand have such poor outcomes from colorectal cancer?: the importance of the pre-diagnostic period
Authors: Firth Melissa , Blackmore Tania , Chepulis Lynne , Keenan Rawiri , Stokes Tim , Elwood Mark , Weller David , Emery Jon , Lawrenson Ross
Published: March 2021

ABSTRACT INTRODUCTION Over 3000 cases of colorectal cancer (CRC) are diagnosed annually in New Zealand. The proportion of late stage diagnoses is higher than in similar countries, and highest in Māori and Pacific patients. Survival outcomes are poorer than for people in Australia and poor for Māori and Pacific peoples. A regional screening programme is not yet available to the entire target population (60–74 years). AIM This study reviews research investigating the pre-diagnostic pathway for CRC in New Zealand and how this may contribute to poorer outcomes. METHODS This was a scoping review of original articles examining the pre-diagnostic period for CRC published on the PubMed database between 2009 and 2019. Findings were interpreted within the Model of Pathways to Treatment framework and in context of international evidence. RESULTS In total, 83 publications were assessed; eight studies were included. Studies were mainly older than 5 years, qualitative, and focused on screening. Facilitatory factors for the appraisal and help-seeking intervals increased CRC public awareness and the critical role of general practitioners. No specific facilitatory or inhibitory factors were identified for the diagnostic interval, but two studies found that time frames did not meet national and international targets. One study discovered longer pre-diagnostic intervals were associated with younger age at diagnosis. DISCUSSION Limited recent research has investigated the CRC pre-diagnostic pathways in NZ. Identification of facilitatory and inhibitory factors and implementation of appropriate strategies to improve them alongside the wider uptake of the screening programme may improve stage at diagnosis and outcomes for New Zealand CRC patients.
Direct single-molecule imaging for diagnostic and blood screening assays
Authors: Ruan Qiaoqiao , Macdonald Patrick J. , Swift Kerry M. , Tetin Sergey Y.
Published: March 2021

Significance

Direct imaging and counting single molecules captured on magnetic microparticles enables diagnostic assays with ultrahigh sensitivities and wide linear detection ranges. The method offers simple assay protocols, short incubation times, minimal reagent consumption, and does not require enzymatic signal amplification. The ratiometric readout, linking the signal and binding area, eliminates the need for strict control over the number of microparticles. Direct imaging provides the sensitivity, flexibility, and simplicity required by rigorous clinical standards. Other benefits of the technique include a seamless transition between digital and analog data analysis modes, scalability, basic consumables, and the reliability to achieve robust implementation in high-throughput automated instruments. HDIA is a versatile tool that can easily be adopted for all receptor–ligand binding assays.
Metastable acceptors in boron doped silicon: evidence of the defects contributing to carrier induced degradation
Authors: Chen Xiaochi , Li Lei , Zhang Jian , Jian Yuan , Yang Guixia , Liu Xuqiang , Zeng Guang , Pang Yuanlong , Yu Xiaofei , Meng Xianfu , Shi Jianmin , Wu Xiaoli
Published: March 2021

This work focuses on the recombination-enhanced reactions of boron related defects in compensated silicon and their impact on the electrical performance of silicon devices. Using deep level transient spectroscopy, we measured the defect spectra in the collector of 14 MeV fusion neutron irradiated p-n-p silicon transistors during forward current injection, as well as the corresponding degradation kinetics of both current gain and leakage current on the same device. Two hole traps at

E

c

+ 0.43 eV and

E

c

+ 0.53 eV are proved to be acceptors in the lower half of the gap with significant recombination enhanced effects. These metastabe acceptors degrade the current gain by changing the space charge distribution in the p-n-p structure and are linked with carrier-induced boron-oxygen complexes responsible for the minority-carrier lifetime degradation of silicon photovoltaics.
Effects of photogenerated-hole diffusion on 3C-SiC/Si heterostructure optoelectronic position-sensitive detector
Authors: Nguyen Hung , Riduan Md Foisal Abu , Nguyen Thanh , Dinh Toan , Streed Erik W , Nguyen Nam-Trung , Viet Dao Dzung
Published: March 2021

Single-crystalline silicon carbide (3C-SiC) has been attracting significant attention in recent years due to its cost-effectiveness and high crystalline quality, mature fabrication techniques on Si-substrate and outstanding mechanical, chemical, and optoelectronic characteristics. Taking advantage of its large built-in potential, a promising application of 3C-SiC on Si (3C-SiC/Si) heterostructure is to develop position-sensitive detectors (PSDs) based on the lateral photovoltaic effect. The lateral photovoltage is generated under non-uniform illumination due to the asymmetry diffusion of photo-induced charge carriers. However, the full potential of 3C-SiC/Si heterojunction-based PSDs has not been elucidated yet. In this study, we investigate the influence of photogenerated hole and its diffusion path length on the sensing performance of the devices in attempts to obtain an optimal design and further pushing the limit of the PSD. Devices with different electrode spacings are fabricated on the 3C-SiC/Si heterostructure, and experiments are conducted under different illumination conditions to determine the position-sensitivity. Devices with short electrode spacings are found to have excellent position-sensitivity with the highest sensitivity of 470 mV mm−1 obtained in a device spacing of 300 µm under 980 nm (1000 µW) laser illumination. The physic mechanism underneath the experimentally observed behaviors are explained based on the generation and separation of electron–hole (e–h) pairs under the illumination, and charge carrier diffusion theory. The findings of this work will provide insights to design highly sensitive PSDs and explore its full potentials.
Origami-based adjustable sound-absorbing metamaterial
Authors: Jiang Pingting , Jiang Tianxi , He Qingbo
Published: March 2021

Broadband acoustic absorption at deep sub-wavelength has become a research hotspot, while current methods still suffer from thick structures and narrow bandwidth. This study proposes an origami-based foldable sound absorber based on micro-perforated resonators. The origami acoustic absorber is composed of six different channels. The resonance frequency of each channel can be easily tuned by origami process under the deep sub-wavelength thickness. When the structure is folded, the thickness is only 20 mm to 30 mm. The operating bandwidth can be tuned from 55 Hz to 80 Hz in the frequency range of 305 Hz to 540 Hz, where the average sound absorption coefficient is beyond 80%. Effective absorption can be realized via a design whose average thickness is only 1/34.4

λ

for the resonance frequency. This study broadens the sound absorption bandwidth and improves the low-frequency sound absorption ability, which provides an avenue for flexible low-frequency noise control.
SEIR order parameters and eigenvectors of the three stages of completed COVID-19 epidemics: with an illustration for Thailand January to May 2020
Authors: Frank T D , Chiangga S
Published: March 2021

By end of October 2020, the COVID-19 pandemic has taken a tragic toll of 1150 000 lives and this number is expected to increase. Despite the pandemic is raging in most parts of the world, in a few countries COVID-19 epidemics subsided due to successful implementations of intervention measures. A unifying perspective of the beginnings, middle stages, and endings of such completed COVID-19 epidemics is developed based on the order parameter and eigenvalue concepts of nonlinear physics, in general, and synergetics, in particular. To this end, a standard susceptible-exposed-infected-recovered (SEIR) epidemiological model is used. It is shown that COVID-19 epidemic outbreaks follow a suitably defined SEIR order parameter. Intervention measures switch the eigenvalue of the order parameter from a positive to a negative value, and in doing so, stabilize the COVID-19 disease-free state. The subsiding of COVID-19 epidemics eventually follows the remnant of the order parameter of the infection dynamical system. These considerations are illustrated for the COVID-19 epidemic in Thailand from January to May 2020. The decay of effective contact rates throughout the three epidemic stages is demonstrated. Evidence for the sign-switching of the dominant eigenvalue is given and the order parameter and its stage-3 remnant are identified. The presumed impacts of interventions measures implemented in Thailand are discussed in this context.
Determination of refractive index on three mediums based on the principle of refraction of light
Authors: Malik A , Mardianti D , Nurlutfiah D , Izzah D W , Mulhayatiah D , Nasrudin D , Suhendi H Y
Published: March 2021

This study aims to develop a tool to determine the refractive index and height of objects in three media based on the principle of light refraction. The method used was an experimental method. The results showed the refractive index values of the three media were quite accurate when compared to the absolute refractive index. The relationship of the angle of the incident ray was directly proportional to the angle of the refractive ray. The angle of light produced will be greater if the value of the given beam angle was greater. Thus, the set of refractive index laboratory tools developed is said to be good and suitable to be implemented in schools to explain the concept of the refractive index of light.
Experiential learning using STEM approach in improving students’ problem solving ability
Authors: Lestari I F
Published: March 2021

This study aims to explore the increase of students’ problem solving ability as the impact of the application of experiential learning using STEM approach. This study use a pre experiment method that is applying the one group pretest-posttest learning design. The participants are 40 students (18 male and 22 female) of second grade Science program in one high school in Province of West Java. The selection of the participants is using random class sampling technique. The data are collected based on the questions that are given to the participants. The questions are divided into five indicators of problem solving ability in Pascals’ principle learning material. According to the result of this study, that using normalized gain, it shows the increase of students’ problem solving ability that can be categorized in high level. The highest score for the students’ problem solving ability is in describing problem and planning a solution, whereas the lowest score is in giving evaluation for the solution of the problem. The result of this study shows that the experiential learning using STEM approach can be used as an alternative to improving students’ problem solving ability, especially in Pascals’ principle.
Spring oscillator as case based learning (CBL) device
Authors: Uskenat K , Iswanto B H , Indrasari W
Published: March 2021

This research aims to: (1) develop and find out the feasibility of a spring oscillator practicum; and (2) practice the spring oscillator tool developed. The research method was the research & development method with the ADDIE development model. The study was conducted at SMAN 1 Indramayu in July-August 2019. The instrument was developed using a laser distance sensor type VL53lX as a distance gauge, a vibrator made from a coil as a spring and LCD system shaker and a laptop to display the results of the experiment. The control system uses Arduino Nano. The study was conducted in March-May 2019 at the Physics Laboratory, FMIPA, Jakarta State University. The experimental results of measuring the spring constant get an average value of 6.527 N / m. The second experiment obtained an average value of the natural frequency of the system at 1.672 Hz. The third experiment obtained a maximum amplitude value of 4.8 cm and a period of 0.59 s. The results of expert validation from media experts, and material experts were 85.16% and 90.04%, respectively. The trial of practicum tools was carried out at SMAN 1 Indramayu, West Java, as many as 20 students with a percentage of 86.66% achievement. Based on the data it is concluded that the spring oscillator practicum tool developed is suitable for use as a learning medium.
Rural and urban students’ attitudes toward physics: a comparative study using Rasch analysis
Authors: Ringo S S , Kuswanto K , Samsudin A , Setiawan A
Published: March 2021

Physics education researchers have put out a large number of papers about attitudes. Yet, only few papers employed Rasch model to analyze data of attitudes. This paper reports a comparative study of students’ attitudes toward physics from rural and urban high schools (n=130). In order to collect data of attitudes toward physics, the Colorado Learning Attitudes about Science Survey (CLASS) was administered online to participated students. Obtained data were analyzed by using Rasch model and t-test. Prior Rasch analysis revealed that all items of the CLASS were fitted the Rasch model and had good psychometric properties. The present research found that there were no significant differences between rural and urban students in terms of attitudes toward physics. This result was in line with some earlier finding, but contrary to other previous result. One of variables probably affecting this outcome was teachers’ unawareness of technology usage and other school facilities to enhance teaching quality.
Evaluation of critical thinking skills of class x high school students on the material of Newton’s laws
Authors: Febriana R , Sinaga P
Published: March 2021

This study aims to determine of critical thinking skills of class X high school students in the material of Newton’s laws. The research subjects used 36 students consist of 18 males and 18 females with their average age 15 years old of class X at one of the high schools in Duri City. The research instrument used is the problem description which was constructed using indicators of critical thinking skills proposed by Ennis. Data analysis is based on the percentage of critical thinking skills. The results of total number of students, aspect of critical thinking skills providing simple explanations worth 49%, aspects of basic skills in making decisions, 39.5% of students were able to work on problems in skills Inference aspects worth 59.3%, aspects of advanced clarification skills worth 56.5%, and on aspects of strategy and tactic skills worth 57%. The results of these data indicate that students’ critical thinking skills are still low. The results of this study can provide teachers as an educator with information and illustration about the condition of students’ critical thinking skills. Teachers can make various efforts in improving students’ critical thinking skills in accordance with the demands of the curriculum in the 21st century.
Introducing physics in early childhood: logic, language, and literacy
Authors: Nasrudin D , Fitriyanti N , Muhtar SN , Dalimunthe R N R P , Nandang A , Hidayat W , Kurnia A
Published: March 2021

Physics is an important subject matter for everyone to learn. Therefore, introducing physics from an early age is a necessity. This paper wants to uncover various thoughts about efforts to introduce physics to early childhood. The method used is a Focus Group Discussion (FGD), which involves experts from physics education, linguists, management, and early education. There are several important points that became the result of the FGD, including (1) physics logic must be made simpler that is easy to understand (2) Mathematical formula which becomes a symbol language does not need to be introduced first. Language skills are needed to understand physics and communicate it (3) Through the right approach, method and media, learning that is delivered by the teacher will make early childhood more literate with physics. This research concludes that physics is possible to be taught in early childhood. We, therefore, recommend that early childhood teachers collaborate with physics teachers in planning, implementing, and evaluating physics learning.
Measuring collaborative problem-solving skills (CPSS) of vocational high school students using web-based assessment
Authors: Azura A , Suwarma I R , Efendi R
Published: March 2021

This study describes an online method for measuring students’ collaborative problem-solving skills individually using two interactive web-based assessment on the webcps program, with students working in pairs. The method used in this research is a qualitative method of case studies of vocational high school students on dynamic electric material. Process flow data was taken from 30 students (17 of them male students and 13 female students) who completed the assignment at one of the vocational high schools in Riau province. Data is transformed into indicators of collaborative problem-solving skills and is categorized based on four levels namely beginner (level 1), emerging (level 2), intermediate (level 3), and advanced (level 4). The results show that students are at various levels with different characteristics in both the social domain and cognitive domain in CPS skills. The assessment used in this study can be used as a measurement tools electrical circuit and as an instrument of measurement for collaborative problem-solving skills.
Promoting the model introducing, connecting, applying reflecting, and extending using Rasch analysis (ICARE-R) to improve students’ critical thinking skills on physics concepts
Authors: Sa’diyah L H , Siahaan P , Samsudin A , Suhendi E , Riani V R , Fatima W O
Published: March 2021

Critical thinking skills are important in physics learning because in physics learning comparable with examination actions on focuses reaching since detecting, formulating complications, collecting data, processing and considering data, and finishing. This study purposes on promoting of the ICARE model to improve students’ critical thinking skills on physics concepts using Rasch Analysis. The research method used a pre-experimental method with one group pretest-posttest design for 21 eleventh grade students (10 males and 11 females) and using Rasch analysis to measure the person reliability. Data were collected by pretest and posttest to measure of the ICARE model and person reliability on students’ critical thinking skills. The results showed that ICARE model persuaded critical thinking skills by the average score of 0.62, categorized as medium. It can be concluded that the ICARE model as one of the learning models that can influence and enhance students’ critical thinking skills.
The impact of PhET virtual lab worksheets on student learning outcomes on sound wave materials
Authors: Halim A , Farhan  , Ahyuni A , Susanna  , Andriani W , Irwandi
Published: March 2021

The need for students’ worksheets is felt urgent and very necessary, especially when the covid-19 pandemic. Therefore, through this research a Student Worksheet (SW) will be developed and the application to increase the understanding of the Sound Wave concept in Middle School students. The development of SW uses a Research and Development approach through the ADDIE model. SW limited trials were conducted on high school students. This research was conducted in 2 cycles of 4 meetings, each of which consisted of 4 stages: planning, implementation, observation and reflection. In addition, the feasibility of the learning tools used, the feasibility of learning, classroom management and students’ responses to learning were examined. Trials on limited samples, test student learning outcomes, teacher skills and student responses. Data analysis method used is descriptive method. Results that being analyzed with descriptive statistics it was found that the use of Lab Virtual PhET SW can improve student learning outcomes and teacher skills in the learning process in each cycle.
Experiments of the law of conservation of mechanical energy using video tracker in high school learning
Authors: Fahrunnisa S A , Rismawati Y , Sinaga P , Rusdiana D
Published: March 2021

Props have been made to prove the law of conservation of mechanical energy using a video tracker, a miniature road Roller Coaster is a teaching aid that will be used for experiments. Through this learning media, it is hoped that it can help the physics learning process of Covid-19. The learning implementation is carried out in one of the high schools in West Bandung Regency in the even semester of the 2019/2020 school year. Determination of the research area using the method of the purposive sampling area, which means the area was chosen deliberately based on specific objectives and considerations. The population in this study were all students of class X MIPA. Using a video tracker is very helpful in the experiential process, the results of the implementation of this learning media can be implemented well as indicated by the results of the achievement of student indicators.
Pedagogical and professional physics teacher training: why hybrid learning is important?
Authors: Mulhayatiah D , Sinaga P , Rusdiana D , Kaniawati I , Suhendi H Y
Published: March 2021

Teacher professional development is inseparable from the process of increasing teacher competency that can be trained through training activities. Training held to improve the pedagogic and professional competence of physics teachers both by the training organizers and the deliberation of subject teachers is generally still conducted face-to-face, even though the teacher has limited time and place in following it. This happens because the teacher also has to carry out his main task of teaching, so we need a training strategy that can be accessed by teachers anywhere and anytime. The purpose of this study is to find out the reasons why in the process of developing pedagogic and professional teachers need learning strategies that are based on hybrid learning. This research method is descriptive qualitative using data collection techniques in the form of interviews, documentation studies, and questionnaires for teacher needs in the implementation of training. The results obtained based on interviews with the training providers showed that the implementation of the pedagogical and professional teacher improvement training was still conducted face-to-face. Meanwhile, the results of the questionnaire distributed to 45 physics teachers showed that most of the teachers stated that they needed training to improve pedagogic and professional competencies, which facilitated the teacher’s training in the form of combining face-to-face and online. This can be done by implementing a hybrid learning training strategy, because in hybrid learning we can combine face-to-face and online training.
The analysis of IRS-7 using the Rasch model on material elasticity
Authors: Bohori M , Liliawati W , Suwarma I R
Published: March 2021

IRS-7 is the abbreviation of 7 (seven) indicators of representing information skills. This study aims to analyze the students’ scientific communication skills regarding the ability to represent information consisting of 7 indicators is: 1) schemes to graphs, 2) verbal to the scheme, 3) verbal to mathematical, 4) schemes to diagrams, 5) schemes to mathematical, 6) graphs to verbal, 7) graphs to mathematical. The skill of representing information is essential in the fourth revolution era and globalization era. This study used a case study approach with a post-test group research design. The sample of this study was high school students in grade XI, as many as 6 male students and 19 female students with an average age of 17 years old. Data were analyzed using Rasch model with the Software Ministeps assistance Version 4.4.1. The results showed that the students had some weaknesses in representing information from graphs into mathematical form 3.4 logits, graphs into verbal forms 3.8 logits, and from images into mathematical forms 5.2 logits. IRS-7 analysis of students on material elasticity can be analyzed properly using the Rasch model.
Effectiveness of use direct learning models for higher order thinking skills of pre-service physics teachers
Authors: Haryadi R , Situmorang R , Khaerudin
Published: March 2021

The purpose of this study was to determine the higher order thinking skills of prospective physics teacher students at the Sultan Ageng Tirtayasa University through direct learning models. The method used in this study is a quasi-experiment with the design of one group pre-test and post-test. The subjects of this study were students of prospective physics teachers at Sultan Ageng Tirtayasa University consisting of 13 male students and 12 female students with an average age of 20 years. The instrument used in this study was a test of high-level thinking skills on magnetic electric material, in the form of 10 breakdown tests. Each question evaluates aspects of analysing, evaluating, create. The average N-gain results in the physics teacher candidates at the Sultan Ageng Tirtayasa University were 0.37 in the medium category. So, it can be concluded that the higher order thinking by using the direct learning model of prospective physics teacher students at the Sultan Ageng Tirtayasa University is included in the medium category. Based on these results it shows that direct instruction learning model is quite effective to improve higher order thinking skills in learning physics, especially magnetic electric material.
Problems of online learning and the use of information and communication technology (ICT) in physics learning at Sumedang, West Java
Authors: Nurliani R , Sinaga P , Rusdiana D
Published: March 2021

This study investigates students’ and teachers’ perceptions of online learning problems and the use of Information and Communication Technology (ICT) in teaching and learning physics in high schools at Sumedang, West Java. The study population consisted of all high school students and physics teachers at one public high school in Sumedang, West Java. The sample was 69 students and 2 teachers selected from one public high school. The instrument used in collecting relevant data for this study was an online questionnaire consisting of 23 items that obtained information about the difficulties of online learning and the application of ICT in schools for learning physics. Data collected were analysed using frequency and percentage calculations. The results showed that online learning can simplify the learning process and mentoring besides ICT being able to broaden students’ insights about physics. However, there are several obstacles in online learning including the limitations of question and answer activities to friends or teachers directly, many assignments, and the lack of ICT facilities.
Real-time data acquisition of dynamic moving objects
Authors: Saputra H , Suhandi A , Setiawan A , Permanasari A , Putra R A
Published: March 2021

The problem frequently encountered in physics practicum activities is measuring instruments in limited reading data variable time of dynamic moving objects. In practical exercises needed the accuracy of measurement data to avoid a mistake in analysis and interpretation data. R-TDA of Dynamic Moving Objects measurement tool is expected to be a solution to overcome these problems. The electronic components used are Infra-Red Obstacle Sensor, connector cable, NodeMCU. The principle of this device is to send a recording time of modulo infrared to the cloud server and accessed via a smartphone and Personal Computer. The results show the sensor a responsive time of 6.8 x 10-11 seconds, and the effect of gravity acceleration of 9,70 m/s2 close to universal gravity acceleration 9,81 m/s2 with an average relative error of 1.22%. The R-TDA of Dynamic Moving Objects has a high response time and accuracy in recording the time of dynamic moving objects.
Critical thinking skills and science process skills in physics practicum
Authors: Firmansyah J , Suhandi A
Published: March 2021

The purpose of this article is to analyze the differences between indicators of science process skills and critical thinking skills in physics practicum. Both of these skills have the same indicators but certainly have differences. How to distinguish definitions and measurements of science process skills and critical thinking skills that are interrelated such as interpretation, inferring and predicting. These three indicators have different meanings in aspects of science process skills and critical thinking skills. The research method used is a literature review with descriptive analysis. The data used in this study are secondary in the form of articles, reports and books relating to science process skills and critical thinking skills in physics practicum. The data collection method used in this study is the documentation method. The analysis shows that the three intersecting indicators have different definitions and measurements. Therefore, in physics practicum, science process skills and critical thinking skills must be measured with different instruments and with different treatments. Critical thinking skills emerge after mastering content and concepts well and comprehensively, while science process skills are trained through the process to obtain physical concepts and content.
Development of circular motion experiment tool using sensor smartphone for high school students
Authors: Raharja E P , Ishafit
Published: March 2021

The growth of smartphone users in Indonesia can be a good potential for various fields, one of which is education. This research aims to produce a circular motion experiment tool using sensor smartphone in the horizontal and vertical position and find out its feasibility for use by high school students. The method of research used is research and development or R&D with the ADDIE development model (Analysis, Design, Development, Implementation, and Evaluation). The research result shows that the experimental tool has shown the influence of object distance directly proportional to centripetal acceleration when the angular velocity is constant. In addition, there is also a difference in tangential acceleration at the top of the circle and under the circle in a vertical position. In the questionnaire test, the average score of the feasibility of the experimental tool was 91.25% with a very good category. While the average score of module feasibility is 86.25% with a very good category. The average score obtained based on the response from students is 94.5% with a very good category.
Does reading comprehension competence determine level of solving mathematical word problems competence?
Authors: Hadianto D , Damaianti V S , Mulyati Y , Sastromiharjo A
Published: March 2021

This study aims to investigate the interaction between problem solving skills in mathematical words and reading comprehension. The method used is correlational by linking reading comprehension competence and ability to solve mathematical word problems. Participants were 300 children aged 9-10 (Grades 3 and 4) taken from 3 school clusters of low, medium and high categories from various aspects. Reading comprehension skills in text and children’s mathematical word problem solving performance are tested. The results showed that the ability to read comprehension had a very strong relationship with the ability to solve mathematical word problems. The ability to understand the relationship between words and words in a sentence that contains problems is crucial for students to solve mathematical word problems. The school cluster chosen also influences the level of children’s mathematical word problem solving ability and reading comprehension skills. From the results of this study, researcher recommend teaching reading and counting in elementary schools be carried out in an integrated manner.
Analysis of external factors affecting students’ achievement student of mathematics education of samudra university
Authors: Fadilah  , Priyanda R , Amalia R
Published: March 2021

The dominant external factors influencing student learning outcomes have been analyzed in this study. The participants of this study are year II and IV students of Mathematics Education FKIP Universitas Samudra in academic year of 2018/2019. Data collection used was questionnaire/questionnaire and interview. Approach and concept in this research using variable annotation with SPSS version 21. Interpretation of result of factor rotation indicate the formation of 3 factors together (main factor). The first to the third external factors that ranked first in the factors that are developing the results of the study of mathematics students FKIP Universitas Samudra in sequence is the community environment, school buildings, and campus environment.