bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of calcination temperature on the structure of iron oxide phase from west Sumatra
Authors: Fauzi Ahmad , Ratnawulan Ratnawulan
Published: May 2021

This research aimed to investigate the effect of calcination temperature on phase changes and the structure of iron oxide contained in iron ore from the area of West Sumatra. Complex geological regions in West Sumatra contribute to the characteristics of iron ore in the area. The calcination temperature used is 26 °C, 300 °C and 500 °C. The characterization tools used are X-ray powder diffractometer (XRD) and X-ray Fluorescence (XRF). The results of the analysis using XRF showed that this iron ore contained Fe content of 69.59% and after being purified at 87.50%. The results of the analysis using XRD indicate that the calcination temperature affects the iron oxide phase formed. At the calcination temperature of 300 °C, the iron oxide phase that appears is Magnetite, Hematite, and Maghemite. At the calcination temperature 500 °C the iron oxide phase that appears is Maghemite and hematite. The calcination temperature also affects changes in iron oxide structure. Structural changes that occur from cubic to cell units a = b = c = 8,3985 Å for Tetragonal structures with unit cells a = b 8,3460 Å and c = 25,0340 Å then to Rhombohedral structure a = b = 5,0320 Å and c = 13,7362Å.
Comparison of building understanding of students on newton’s laws with phenomenon-based ADI with assessment formative and ADI models
Authors: Parno  , Mufidah J , Diantoro M
Published: May 2021

The Newton’s laws cannot be separated from mechanics and real life phenomenon, but research is rarely done on improving understanding of Newton’s law through ADI-Phenomenon-AF. The purpose of the research was to compare the effectiveness between ADI-Phenomenon-AF and ADI models in building understanding of Newton’s law and describing students’ difficulties after the learning process. This study used a mixed method design with an embedded experimental design. The instrument of this study was Newton’s law Understanding Test in the form of reasoned multiple-choice questions with a reliability of 0.817. The research data were analyzed by Wilcoxon test, Mann-Whitney U test, N-gain, d-effect, and a description of the reasons for students’ answers. The results show that both models are effective in building students’ understanding, but the ADI-Phenomenon-AF model is more effective than the ADI model. After the learning process the students of both classes still have difficulty in analyzing the relationship between acceleration, force, and mass. In addition, ADI-Phenomenon-AF class students still have difficulty with the nature of force in Newton’s first law, while the ADI class analyzes the application of Newton’s first and second laws.
Validity of interactive student worksheets based on inquiry based learning models to improve knowledge competence
Authors: Samudra E YA , Yulkifli Y
Published: May 2021

Physics learning activities have not been carried out optimally as seen from the low competency of students’ knowledge. This is due to the lack of available teaching materials that fit the needs of students, the available teaching materials are very limited because they do not take advantage of technological developments and there is no model in them, so learning is not entirely student centered. Utilization of technology is one of the efforts to facilitate learning in accordance with the needs of students by developing non-printed teaching materials in the form of interactive student worksheet based on inquiry based learning models. The purpose of this research is to produce an interactive student worksheet based on a valid inquiry based learning model. This type of research is research and development using the ADDIE model. The method used in this research is descriptive statistics. The validity of the interactive student worksheet is assessed by three experts using a validity questionnaire. The validity of the interactive student worksheet is analyzed using the Aiken’s V. formula. The validation results show that the material validity aspect is 0.87; visual display 0.89; and learning design 0.85. Based on the analysis of the validity of interactive student worksheets data, an average of 0.87 is in the valid category. Thus, Interactive Student Worksheets based on inquiry based learning model can be implemented in physics learning to increase knowledge competence.
Validity of physics e-handouts based on the STEM approach to improve students’ knowledge competency
Authors: Yulia Sri Rahma , Pratiwi Yulia , Ramli Ramli
Published: May 2021

Physics e-handouts based on the STEM approach to improve students’ knowledge competence is able to facilitate students to increase knowledge optimally. Before using this e-handout, an e-handout feasibility test is needed. The purpose of validation is to determine the suitability of e-handout with physics learning material by using the Aiken’s V formula by 4 validators. Data collection by questionnaire method. Validation is assessed from 3 aspects, first the Material Substance Eligibility with a value of 0.80 is a valid category, secondly a visual display worthiness obtained of a value of 0.85 with a valid category. Third, the feasibility of the learning design obtained a value of 0.81 with a valid categorization. The overall conclusion is that the validity value of the physics e-handout based on the STEM approach is 0.82 with a Valid category. So that e-handouts are appropriate to be used in physics learning to improve the competency of high school students’ XI knowledge.
Mapping environmental curriculum in physics learning at senior high school grade X semester 2
Authors: Yusliani Erlina , Desnita
Published: May 2021

Global issues about the environment become a tranding topic and often heard in today’s era. There have been many reports of environmental damage occurring in Indonesia, ranging from floods, forest fires, waste handling problems, air pollution and landslides. So that it takes the care of the young generation for the environment from an early age by providing environmental education in schools. Environmental education given to students will have a positive impact, namely students are able to solve and prevent environmental problems they face. Environmental education will foster students’ environmental literacy. Environmental literacy is needed so that students are responsible and care for their environment. Therefore, it is necessary to instill environmental literacy in children from an early age through formal education, by integrating it in the learning process. One of them is by integrating through the subject matter that will be taught to students. The purpose of this research is to map the hidden environmental curriculum in the physics learning materials of senior high school grade X semester 2. This research is a descriptive study with a qualitative approach. This study describes the physics material for grade X semester 2 which contains environmental literacy. The data collection technique used in this research was through documentation study and the data analysis technique used in this study was the content analysis technique. The results of this study are in the form of an integrated environmental literacy matrix which can be used as a reference for physics learning tools.
Analysis of physics e-books assisted by application of learning house using quantum learning models to improve the 21st century skills of high school student
Authors: Sawitri Y , Asrizal A , Mufit F
Published: May 2021

At this time, known as the century of openness and globalization, human life has changed and is different from previous lives, this century is known as the 21st century. 21st Century is also known as the era of knowledge, which is all alternative efforts to meet the needs of life in a variety of more knowledge-based contexts. The 21st century education paradigm has experienced a shift marked by differences in learning orientations. The learning of the previous century emphasized literacy in reading, writing, and mathematics, in which in the 21st century they were used as the basis for developing new literacy, namely human, data and technological literacy which is very important to face the current and future globalization era. The problem found in the field is the low skill of students there are three. First, learning physics in schools is very theoretical and mechanistic. The learning process begins with an explanation of concepts accompanied by examples, followed by work on exercises in Physics questions. Secondly, schools do not arrange the learning environment. Third, students have difficulty learning physics. This is supported by the results of interviews with students that one of the subjects considered difficult is physics. This is caused by their ignorance of the benefits they get from studying physics. Based on the preliminary analysis conducted, the first it was found that Value Of Physics Learning is for the preliminary and closing components is 78 for preliminary activities and 78 for closing activities. The learning process delivered by the teacher should not only provide knowledge to students, but students who must build skills in their own minds. The results of the data analysis show that: the implementation of learning components and strategies using the quantum learning model in physics learning are grouped into sufficient categories, the use of e-books is that physics teachers have never used them, teacher only uses printed books or modules in learning. Therefore, the results of this study can be used as a basis for designing and developing the required physics e-book to increase student knowledge.
Preliminary study of physics e-module development using research-based learning model through smartphone to support digital learning in the revolutionary 4.0
Authors: Apriani M F , Yulikifli
Published: May 2021

The era of revolution 4.0 emphasizes the application of technology in life, including education. Example of the application of technology in education is digital learning which helps students teach technology to help them in the future. In physics learning, the use of technology is still not optimal. This is indicated by Physics learning materials used in schools that are still in print and learning activities are still centred on the teacher face-to-face. The spread of the Corona virus causes learning activities cannot be done face-to-face because not all schools are permitted to carry out learning activities. Therefore we need electronic learning materials that are able to improve the competence of attitudes, knowledge and skills of students even though not face-to-face. E-module with Research-based Learning model through smartphone is very appropriate learning material used to improve these three competencies and support digital learning. This study analyzes e-module development using Research-based Learning model in 10th grade physics subject on the first semester that discusses the analysis of needs, characteristics of students, materials and task analysis. Research method used is quantitative descriptive research with research sample are students of SMAN 10 Padang, SMAN 12 Padang and SMA Pertiwi 1 Padang.
Practicality of interactive multimedia of natural science integrated with the theme of motion in life using an integrated scientific approach to 21st-century learning
Authors: Kurniawati Annisa , Ratnawulan  , Fauzi Ahmad
Published: May 2021

This interactive multimedia was developed using a scientific approach and integrated with the characteristics that exist in 21st-century learning. The practicality test aims to assess the practicality of the interactive multimedia products being developed. The practicality test was carried out by distributing a questionnaire in the form of an instrument sheet for the practicality of the response of educators and the responses of students to 2 educators and 15 students. The data analysis technique to assess the practicality of the product is the Likert scale. The result is an Integrated Natural Science interactive multimedia developed with very practical criteria so that students and educators can use it in teaching and learning activities.
Preliminary research in the development of smartphone-based e-module learning materials using the ethno-STEM approach in 21st century education
Authors: Azis Hasbi , Yulkifli
Published: May 2021

Education is the most important aspect in building knowledgeable and skilled human resources in the field of technology and 4C Skills known as the 21st century learning paradigm. In addition, education based on local culture related to scientific fields also needs to be considered as it is hoped that the emergence of new knowledge adapted from the local culture. Physics learning should lead students towards the desired learning goals and the role of teaching materials can also influence this. This study aims to obtain information related to the application of smartphone-based E-module using the Ethno-STEM approach. This research is a descriptive study conducted through direct observation at 3 schools with the research sample being students of class XI MIPA and 2 physics teachers in grade 11th and used an instruments in the form of questionnaire and interview sheets. The results of the data analysis show that the application of the Ethno-STEM approach has never been applied in learning. The need for teaching materials that support learning has to be up-to-date, namely smartphone-based E-Modules. Due to this, it is necessary to carry out further research in the form of the development of a smartphone-based Physics E-Module using the Ethno-STEM approach.
Validity of physics edupark e-book with scientific approach based on tourism destinations of Rumah Gadang
Authors: Sadraini  , Rifai Hamdi
Published: May 2021

The 21st Century is known for being digitally based and technology that has an influence on learning. The curriculum 2013 seeks to perfect learning based on regional contexts and technology. Lack of integration of learning material with regional contexts and technology utilization makes it difficult for students to understand the concepts of physics. Teachers and students not yet using non-printed in learning material that integrated with the regional context. One of the solutions to this problem is that non-printed in learning material has been created in the form of e-book Edupark physics. The purpose of this study was to produce a physics Edupark e-book with a scientific approach based on tourism destination of Rumah Gadang with valid criteria. The type of this research is educational design research (EDR) using the Plomp development’s model. This stage called prototyping phase I to see the validity of the physics Edupark e-book that was designed. Validation was carried out by three experts, namely physicists, learning or display design experts, and linguists. The data analysis technique used Aiken’s V formula. Based on the results of the study, it can be concluded that the physics Edupark e-book with a scientific approach based on tourism destination of Rumah Gadang is very feasible, so that it is declared valid from the components of the material substance, learning design, display and language worthiness.
Validity and practicality of worksheet assisted by PhET interactive simulations to improve students creative thinking skills in a research based learning model
Authors: Chotimah C , Festiyed
Published: May 2021

Research has been carried out to determine the validity and practicality of the sheet using interactive simulations. This study aims to describe the validity and practicality of worksheets as a learning tool in research based learning model. The method used is descriptive analysis of quantitative data, the teachers response and the students responses to the questionnaire instrumen. The result showed that the validation of the students worksheet obtained an average score of 0,83 on the aspects of the feasibility of content, presentation, and language. The practical result obtained for the teachers response were 75% with the practical category and 81,70% for students responses with the very practical category. Based on the results of the developed phet assisted worksheets, it is stated that they are valid and practicality used in research based learning to improve the creative thinking skills of students at the high school.
Practicality of high school physics e-book integrated materials of meteor fall disaster mitigation based on guided inquiry model assisted google classroom
Authors: Alkadri Robika , Fauzi Ahmad
Published: May 2021

Learning media is a very important learning component who use by teachers for students in the learning process. The development of Information, Communication and Technology have big contributed for teachers to develop learning media as needed by students in learning. The purpose of this research is to analyze the media used by students in high school physics learning and to determine the right media in the development of flood-themed teaching materials. This research method is descriptive qualitative approach. Descriptive method is a method used to examine the condition of the natural objective.To obtain research data used questionnaire instrument. Instrument for retrieving data in the form of a questionnaire for analysis of learning media filled in by students. The result of the study showed that the use of learning media based on electronic can be used in physics learning and develop flood-themed teaching materials based on electronic.
Effects of science learning material of motion in daily life theme on new literacy of students
Authors: Yurnetti  , Asrizal  , Murtiani  , Usman E A
Published: May 2021

The 21st century demands education graduates have various skills. One of the skills needed is literacy skills. This literacy ability can be instilled in the learning process. However, the integration of literacy and the implementation of integrated science learning is still low. The solution that can be done is to develop science learning material by integrating new literacy. This study aims to determine the effect of using natural science learning material with the theme of motion in daily life integrated with new literacy on increasing the knowledge and skills of new literacy students of class VIII. This study used a before and after design with one sample group. The research subjects were 32 grade VIII students of SMP Negeri 1 Solok. The instrument for data collection consisted of two instruments. First, the knowledge aspect assessment instrument in the form of a written test consisting of 10 questions in the form of essay questions. Second, the skills aspect assessment instrument in the form of a performance appraisal sheet to assess students’ new literacy skills. The data analysis technique used descriptive analysis, normality test, homogeneity test, and correlated comparison test if the data were normally distributed and had the same variance. The Wilcoxon signed-rank test analysis is used if the data are not normally distributed and are not of the same variance. Therefore, an important result of this study is the use of science learning material on motion in daily life theme has a significant effect on increasing the knowledge and new literacy skills of grade VIII junior high school students at a 95% confidence level.
Assessing pre-service physics teachers’ competencies in designing photo-electric effect experiment using PhET simulation
Authors: Aminoto T , Pujaningsih F B , Dani R , Riantoni C
Published: May 2021

The advancement of learning technology requires that pre-service physics teachers should have adequate skills to integrate technology in the teaching and learning process. This study aimed to investigate the competencies of prospective physics teacher of Jambi University in designing the photo-electric effect experiment. This study used a mixed method approach with exploratory models. Ninety physics education students of Jambi university, having taken modern physics subject, were participated. Data were obtained from the students′ work of designing photo-electric effect experiment using PhET simulation. The students were asked to work in group, but the final report was done individually. Data analysis were done based on indicators of competencies to design a virtual lab activity. The indicators consisted of abilities to declare the objectives of experiment, compile the theoretical basis, and set up the procedure. The findings showed that the average ability of the prospective physics teacher in designing photo-electric experiment using PhET simulation was in the low category. Based on interviews, it was due to aspects of unfamiliarity with PhET simulation, technical problems related java player installation, insufficient of prior knowledge, and lack of skills in finding relevant information.
Interactive recitation methods as a solution to the students’ deepening physics material during the Covid-19 pandemic
Authors: Sundari P D , Dewi W S
Published: May 2021

The spread of Covid-19 in Indonesia has an impact on the implementation of learning at various levels of education, including higher education. During the Covid-19 pandemic, the implementation of learning is conducted by online learning. Students should be able to learn independently to understand learning material. This research purposes to describe the interactive recitation method as a solution for the students’ deepening of learning material during the Covid-19 pandemic. This research was conducted in odd semester 2019/2020 in the general physics course at Universitas Negeri Padang involving 141 students. Data were collected through survey, observation, interviews, and document analysis. The results showed that students’ understanding of the concept was still low for each lecture material. This can be seen from the mistakes of students’ answers to the questions given during lectures. Students have difficulty to memorize the physics concepts for a long term memory. So, an interactive recitation method needs to be developed as an solution to deepen lecture material. The interactive recitation method is loaded with various conceptual questions for each lecture material including feedback, and its makes easier for students to learn physics concepts independently during the Covid-19 pandemic.
Development of online learning device based on demonstration models on heat transfer materials
Authors: Serevina V , Priane W T
Published: May 2021

Whether we realize it or not, the faster and rapid development of technology has an impact on the faster and faster progress in the world of education. During the current covid-19 pandemic, much needed online learning tools, the concept of home-schooling has never been mainstream in the national education discourse. Because the teaching system has been changed through online learning, there is a need for the development of learning tools for teachers to be able to continue delivering material to their students. This study aims to develop online learning tools based on demonstration models on effective heat transfer material during the covid-19 pandemic. The development of this research uses the ADDIE model with stages of development: 1. Analysis, 2. Design, 3. Develop, 4. Implement, 5. Evaluate. Learning tools are made online to make it easier for teachers and students to carry out teaching and learning activities during online learning. Validation was carried out by 3 experts, namely media experts, material experts, learning experts and tested on students. The results of the analysis of the validation of material experts obtained an average percentage of 86.80 % in the very high category, the results of the analysis of learning experts obtained an average percentage of 88,70 % with a very high category, the results of the analysis of the media expert obtained a percentage of 86,70 % with a very high. The subject was tried in class XI high school. Data collection instruments using a questionnaire through the Google form. From the results of the development of online learning tools based on online demonstrations on heat transfer material obtained learning tools (Free Learning Implementation Plan, Worksheet and online media) have been tested for eligibility by experts and field trials with good criteria and are suitable for use.
Development of instruments for measuring contextual-based video quality of fluid for physics at senior high school grade XI
Authors: Desnita  , Festiyed  , Novisya Dira , Marsya Putri Bullquis , Hamida Sadra
Published: May 2021

Contextual learning videos present various events related to the topic of the lesson. One of the benefits of contextual-based learning videos is to improve critical thinking, creative thinking, collaboration, and communication skills (4C). The requirement for a video to meet the standards as a learning medium is valid, practical, and effective. An instrument is needed to measure the three the quality standard of the learning media. The instrument must meet valid and reliable criteria. An instrument has been developed to measure the validity, practicality, and effectiveness of CTL-based fluid learning videos for high school physics lessons level XI. The instruments consist of (1) validity according to expert physics learning and physicists, (2) practicality according to senior teachers and high school students, and (3) effectiveness for measuring critical thinking skills, creative thinking, collaboration, oral communication, and written communication; over all 9 instrument units. Expert validation tests have been carried out and all instruments are considered valid. Experts, teachers, and students have tested the use of instruments, the test results show that all the instruments are reliable. Based on the results obtained, it can be concluded that the instrument made meets the standards as a measuring tool for the quality of contextual-based fluid learning media.
Validity and practicality book chapter’s model on thermodynamics and mechanical waves material integrated new literacy and disaster literacy of students for grade XI high school
Authors: Anori S R , Mufit F , Asrizal
Published: May 2021

In the 4.0 revolution era, 21st century skills are needed that will build superior human resources who can compete in their lives. One of the 21st century skills is literacy. However, the real conditions that occur indicate the lack of new literacy and disaster literacy abilities possessed by students. The solution made to overcome these problems is to develop a book chapter’s model integrated new literacy and disaster literacy. The type of research carried out is Research and Development (R&D) with Sugiyono’s development. The instrument used was an instrument at the potential and problem stage consisting of observation sheets of physics learning implementation, document analysis sheets, and analysis sheets of students’ initial knowledge tests in physics learning, then the validity test instruments and practicality test instruments. The results of data analysis from the research are book chapter’s model integrated with new literacy and disaster literacy with a validation value of 79.78 with good category and a practical value of 84.77 with excellent categories. So, it can be concluded that the book chapter’s model on thermodynamic and mechanical waves material integrated new literacy and disaster literacy is valid and practical for students of grade XI high school.
Problems of students in following the online learning process in the covid-19 pandemic
Authors: Akmam A , Hidayat R , Mufit F , Jalinus N , Amran A
Published: May 2021

The Covid-19 pandemic requires people to work remotely from home or Work from Home (WFH), including lecture activities. The goal of WFH is to break the chain of spread of the corona virus. Transfer of lecture activities from campus to home as an effort to maintain social distancing. Like it or not, students must learn more independently. Many students respond well to online learning when it is implemented. However, students actually experience difficulties in learning after the online lecture process is running which has an impact on decreasing the quality of their learning. This survey research aims to determine the obstacles faced by physics students in participating in the online learning process during the Covid-19 pandemic. The research sample of 331 respondents who have participated in the online learning process activities in the Covid-19 pandemic were taken randomly. The research instrument was a questionnaire sheet distributed on google form for 20 days. The results showed that students tended to choose the learning process on campus compared to studying online. The factor influencing online learning are the internet network, the readiness of students to receive and send information and the accessing the Learning Management System (LMS). The influence of these factors is found by students when they take courses in Disaster Management, Fundamental Physics, Mathematical Physics, Computational Physics, Algorithms and Computer Programming.
Need analysis for the development of mobile virtual laboratory in junior high school for electricity and magnetics topics
Authors: Oktavia Rani , Putri Rahmah Evita , Arif Khairil
Published: May 2021

Science is compulsory subject at the junior high school level. Mastery of science material by students is highly prioritized so that students have the skills to solve daily problems related to science. One of the ways to develop this skill is by doing practical work. Electricity and magnetism are science subject matter that students should follow in the form of practical work because this material has a lot to do with problems in everyday life. However, the limited duration of learning time at school makes some science subject matter that should be studied in the form of practical work cannot be implemented. This happens because of the large amount of material that must be taught in accordance with the demands of the curriculum. Other factors that lead to not carrying out practical work are incomplete science laboratory facilities, inadequate teacher experience, and conditions that do not allow learning to occur directly in schools. The Mobile Virtual Laboratory is a virtual laboratory that can be accessed by students via an Android-based mobile phone so that students can learn practical work anywhere and anytime. This article describes an analysis of the needs of the Mobile Virtual Laboratory in teaching science in junior high schools for electricity and magnetism.
Development of inquiry based learning model - based student worksheets through the 21st century science process skills approach to grade XI physics learning
Authors: Widestra R A , Yulkifli
Published: May 2021

Students in the learning process are still not optimal and active in learning activities. One of the contributing factors is that the available Student Worksheet is still in print and has not contained model steps and learning approaches that lead to student activities. The purpose of this research is to establish a learning model based on interactive student worksheet inquiry. The model has a comprehensive scientific literacy and scientific process skills method to conduct eleventh grade physics learning with effective and practical standards.. This type of research is development research using ADDIE model consisting of analysis stage, design, development, implementation, evaluation. Research instruments include preliminary study questionnaires, validity questionnaires and practical questionnaires.. Data analysis techniques for validity use Aiken’s V formula, for practicality using descriptive percentages and effectiveness using N-gain score The results of the analysis stage show the need for the development of interactive student worksheet Development results show student worksheet is on a valid criteria with a value of 0.87; Practicality scores are very high based on the response of students and teachers with average scores of 84.76% and 96.45% respectively. t. Thus, it can be concluded that the student worksheet inquiry based learning model with a process skills approach to grade XI high school physics learning meets valid, practical criteria.
Development of virtual reality-based learning media on electromagnetic wave radiation material
Authors: Shepa M J , Serevina V , Astra I M
Published: May 2021

The aim of this study to develop virtual reality-based learning media on electromagnetic wave radiation material. The research method used the research and development (R & D) with the ADDIE models (Analysis, Design, Development, Implement, Evaluation). Data collection techniques used through observation and questionnaires. The development of virtual reality - based learning media was done in School of St. Yoseph Bekasi. This development research was conducted on science subject teachers. This virtual reality-based learning media has been validated by experts, that is content experts and media experts by providing validation instruments. Virtual reality-based learning media can be used to simulate a learning process that does not allow direct involvement because it will be dangerous for learning participants in this covid19 pandemic era. So, the virtual reality-based learning media just tried to the teachers and experts. The conclusion of this research was the development of virtual reality-based learning media on electromagnetic wave radiation material can be used as a learning resource for students.
Validation analysis of basic electronics textbooks 2 integrating creative thinking in the Physics Department, Universitas Negeri Padang
Authors: Hufri
Published: May 2021

This study aims to determine the validity of basic electronics book 2 by integrating creative thinking skills. This type of research is research and development (R&D) using the ADDIE design model, the research steps include : analysis, design, development, implementation, evaluation. The data collection instrument used is a validation sheet that has been previously validated by the validator. Based on the results of data analysis of the validation of basic electronics book 2 by integrating creative thinking skills, an average value of 86.6% was obtained with very valid criteria.
Infrasonic observation of microbarom signals in the middle latitude: An investigation of summer and winter season on the upper atmosphere
Authors: Batubara M , Yamamoto M-Y
Published: May 2021

We report the result of infrasound observation applied to microbaroms between peak winter and summer season of 2018, obtained from ambient noise. For our study several infrasound sensor over Shikoku island was used, which had been installed since 2015. Observation of our microbaroms shows regular pressure variations of a few milliPascals at around 0.2 Hz produced by the incoming of infrasound arrived from the ocean fields. As the result, their amplitudes show prominent greatly in winter time expect to depend on the appearance of the atmospheric sound ducts between the surface and the level at certain altitudes. These ducts depend on the wind structure and vertical temperature of the atmosphere. For our station close to the ocean, sound ducting from the oscillation wave of the ocean surface, requires strong contribution westerly winds at certain upper reflection point. With a global reanalysis horizontal wind assimilation, the seasonal wind structure at our geographical study, near 33° N, is shown to distinguish and to account for the observed profiles of microbaroms. Finally, we suggest that use of our network of infrasound sensors would provide a global complementary result to monitor the upper atmosphere conditions in the middle latitude regions.
A comparative study of sound sources separation by independent component analysis and binaural model
Authors: Atmaja B T , Arifianto D
Published: May 2021

Humans’ auditory system can separate mixed sounds based on their sources easily. However, mimicking this ability by computer algorithm is not an easy task. Some approaches have been developed, particularly based on the statistical approach and binaural modeling. From statistical methods, independent component analysis (ICA) grows fast to mimics sound separation and localization by human auditory processing. On the other side, mathematical modeling to model binaural hearing has been built block by block. This paper is a comparative study of both approaches, a statistical method represented by FastICA and binaural modeling represented by the frequency domain binaural model. The task is to mimic how to binaural processing works to separate sound sources. The result of the comparison was given by the perceptual evaluation of speech quality (PESQ) and Itakura-Saito (IS) distortion measurement. PESQ scores ICA method obtains better performance than the binaural model while, in contrast, IS scores the binaural model better than ICA.
Sound absorption behavior of woven fabrics as micro perforated panel absorber
Authors: Gunawan  , Prasetiyo I , Adhika D R , Brahmana F , Yuliarto B
Published: May 2021

Woven Fabrics are potentially developed as a sound absorber system because of the presence of micro perforation on their surface. By introducing air cavity backing the woven fabrics up, such system can undergo Helmholtz resonator mechanism as found in micro-perforated panel (MPP) absorber system. The micro perforations in a woven fabric are formed by yarn in x (weft) and y (warp) direction. The perforations can create a viscos-inertial effect when interact with sound fields that is useful as a basis for sound absorption mechanism. In this study, the works are focused on investigating the relationship of micro hole of woven fabric material to sound absorption characteristics. For this, micro holes are developed by controlling weft density. Meanwhile, the sound absorption coefficients are evaluated by measurement using impedance tube. From this study, it can be concluded that the sound absorption coefficients of woven fabric are affected by weft density variation by which the perforation parameter can be varied. Moreover, the performance of woven fabrics are promising as indicated by absorption coefficients that is ranging from 0.71-1.00 with absorption bandwidth of 3 kHz-5 kHz.
Performance evaluation of smartphone-based vibration meter application software
Authors: Prasasti N R , Putri C C , Hermawanto D , Dwisetyo B , Utomo F B , Palupi M R , Rusjadi D
Published: May 2021

Modern smartphones have been equipped with MEMS sensors allowing them to be used for advanced purposes. A MEMS accelerometer is embedded in the smartphone to sense motion and vibration. Recently, many smartphone-based vibration-meter applications software employed the embedded accelerometer and used them for vibration monitoring and field measurement. However, the accuracy of this kind of vibration meter has not known yet. In this paper, we discuss about the evaluation of smartphone-based vibration meter using the standard method for vibration meter calibration described in the ISO 16063-21. A vibration measurement by the smartphone-based vibration meter is compared to the reading of the reference accelerometer type B&K 8305. The evaluation was conducted in a frequency range of 10 Hz to 50 Hz with the amplitude of 0.1 G to 1 G. This study showed that the accuracy of the smartphone-based vibration meter is decreased in the higher frequency range.
An acoustic exploration of event construals in Bengali language
Authors: Chowdhury S , Gayen P K , Sarkar U , Banerjee A , Sanyal S , Karmakar S , Ghosh D
Published: May 2021

The world is full of events, and events are construed. One of the major research questions, therefore, seeks to understand the way events are construed through language. Event construals involve the syntacto-semantic properties of certain linguistic categories such as Verb, Tense, Aspect, Modality, etc. Serial Verb Constructions (SVC) and Complex Predicate Constructions (CPC) are no exception to this very fact. In this work, we look forward to compare both linear and non linear acoustical features generated from SVC and CPC events found in sentences of Bengali language. For this, we recorded 60 common utterances of Bengali language containing SVC and CPC events individually (around 36 of them belong to SV category while the rest belong to CP category), from 1 male and 1 female native Bengali speakers. The serial verb construction in these utterances may contain two (2) serial verbs in either simultaneous or sequential order, while few sentences are such that they can be interpreted both as SV or CP events. The main objective is to look for robust acoustic features which lead to perceptual categorization of events as SV or CP with a particular linguistic background. Various linear features like MFCC (Mel frequency Cepstral Coefficients), spectral skewness/energy, pause duration, pitch profile and nonlinear features like Fractal Dimension (FD) have been employed for the classification purpose. This work is a pilot study of an ongoing project which looks to explore the concept integrating capacity of human brain in terms of Syntactic Compositionality or Semantic Combinatorics in a complex sentence. This preliminary acoustic study reveals interesting new results in terms of perceptual linguistic representation of the event construals.
Study of the phase transition of a medium using reverberated signals
Authors: Farhat Y , Bustillo J , Achdjian H , Sabra M N , Zaouk D , Fortineau J
Published: May 2021

Non-destructive testing (NDT) methods nowadays are essential in materials and structures control due to their capability to not affect the integrity of material. These methods are particularly efficient for the monitoring of resin or composites formation. In particular, ultrasonic technics can be used to evaluate mechanical properties of materials by measuring acoustic waves characteristics. In general classical characterization techniques, based on linear measurements, give local information’s of medium. Reverberation methods, classically used in room acoustics, allow global characterization. This approach is not so common in NDT or structure monitoring. The reverberation signals which contain global information about propagation media properties, are highly dependent on the boundary conditions. Sabine’s formula gives the relationship between reverberation time RT and wall attenuation coefficient can be adapted in many acoustic applications. Previous studies established a relation between RT and solid interfaces absorption. In the case of a sol-gel material, the reverberation time measured in a metallic block can be linked to the material properties such as density or viscosity. The RT will vary during the phase transition of our material from liquid to solid state. Hence, our motivation is to derive the equation of the acoustic intensity for solid interface absorption considering the shear and the longitudinal waves. Furthermore, to estimate the reverberation time from the determined acoustic intensity (simulation part) and to compare the results with the experimental part. For this reason, experiments were performed to validate the simulation part. Measurements are preformed in an aluminium mold using five piezoelectric (PZT) patches, one being used as emitter and the others as receivers has been studied and it’s evolution is shown to lead to a good estimation of the phase transition time.
A silencer design and analysis of the effect of silencer perforation towards resonant frequency and insertion loss in a duct
Authors: Suyatno  , Panggabean N B
Published: May 2021

A silencer model was designed for application to HVAC systems, specifically for noise control in ducts. The goal was to see how the perforation of the silencer affected the resonant frequency and Insertion Loss (IL), as well as analyse physical phenomena that occurred in system. The materials used were 1/2-inch PVC pipes 5 cm in length and acrylic with a thickness of 2 mm used as the silencer frame. The varied parameters were the amount of PVC pipes (percentage of silencer perforation) from 0 holes (no perforation) to 10 holes. It is concluded that perforation affects the resonant frequency through changes in acoustic mass and affects the IL through acoustic resistance. It is inconclusive whether the resonant frequencies generated affected IL. It is assumed that negative valued IL observed at lower frequencies occurred due to resonance between the sound and duct (structure-borne sound) which increased sound pressure level, or that these may be the actual resonant frequencies generated. Further research is needed to study the generation of resonant frequencies and structure-borne sound in the system, study airflow and thermal performance of a HVAC system when the silencer is applied, the transmission loss (TL) of the silencer and optimisation of the design to improve low-frequency sound attenuation.
Tracking of an underwater source using sparse method
Authors: Pratiwi R U , Arifianto D , Anggrayni E , Widjiati E , Sukirman O , Amelia R R
Published: May 2021

The sparse method or better known as compressed sensing (CS), is a method often used for the signal reconstruction process. This method had considered better than conventional methods because it can reconstruct a signal with a smaller amount of data. Many algorithms had used for signal reconstruction using the CS method, including l1-minimization and orthogonal matching pursuit (OMP). In this study, the two algorithms were used for signal reconstruction of underwater objects and then compared to find out which algorithm is better for the signal reconstruction of underwater objects. Comparing the two algorithms had based on parameters in the form of PSNR and RMSE against sparsity. Based on the simulations that had been doing, known that the l1-minimization algorithm can reconstruct signal up to 40% sparsity. Whereas the OMP algorithm can only reconstruct signals up to 30% sparsity. PSNR and RMSE generated from the l1-minimization algorithm show that this algorithm provides better reconstruction results than OMP for underwater object signals. The results obtained show that the best tracking process is at an angle of incidence of 90°.
Folded planar resonator-based sonic Crystal scatterer: Part I. Shifting from split tube resonator design
Authors: Yahya Iwan , Suparmi  , Cari  , Ubaidillah
Published: May 2021

A split tube resonator (STR) is one of the typical base structures in many previous acoustic metamaterial structures. This paper introduces a brand new approach to designing the tunable concentric wall resonating structure to look like a similar shape but with a different response and performance to STR. The central concept is a planar resonator folded outward and inward direction. We found that the proposing approach gives the possibility for a single geometrical dimension tunable sonic crystal element that could not occur in a single degree of freedom conventional STR. The test model made of stiff paper and the sound absorption performance test conducted experimentally with impedance tube refers to ASTM E-150-98 standard.
Research and design of digital unit for direct digital frequency synthesizer
Authors: Lei Tong , Liang Liu
Published: May 2021

The direct digital frequency synthesizer (DDS) is a new kind of all digital frequency synthesizer, which has fast frequency switching speed and high frequency resolution. It has been widely used in the field of signal processing. In this article, we analyze the basic principle of DDS and study several methods of phase-amplitude conversion. We use the method of searching ROM table for rough rotation and the optimized CORDIC algorithm based on excess-fours structure for fine rotation to achieve the phase to amplitude conversion. The power consumption and area of the fine rotation element are reduced with the preprocessing of the phrase. The output frequency is increased by using a 4-channel-interpolation structure. After the design is completed, we verify its correctness and evaluate its performance. The results show the phase-amplitude conversion algorithm meets the need of correctness and the DDS can work stably at 1GHz.