bluuebunny/crossref_metadata_2025 huggingface dataset:
Bajo’s Adventure: An effort to develop students computational thinking skills through mobile application
Authors: Kusnendar J , Prabawa H W , Rahmanda
Published: November 2019

The thought of the need for ownership and developing computational thinking skills emerged in the last few decades. This raises a number of other interesting derivative ideas, including how to teach and train computational thinking skills in students. This study aims to develop a game-based mobile application that can be used as a means to train computational thinking skills. In addition, this study also aims to identify the relationship between learning experiences that students get through the mobile application with some basic abilities in computational thinking, especially in terms of generalizing and algorithmic abilities. The data shows that the ability to think student computing can be formed and even improved in a relatively short period of time through media that is discerning to teach and train computational thinking skills. Nevertheless, the teacher’s role is still needed that is pedagogically able to facilitate the students deadlock in connecting what students have gained through the media with the concepts they want to teach.
An investigation of blended learning in at-home and in-school education of information ethics using tablet PCs
Authors: Sasaki H
Published: November 2019

The goal of this study is to develop a blended learning in at-home and in-school education of information ethics using tablet PCs and to evaluate the effectiveness of the lesson. Information technology such as the internet and smart phones in society has been progressing speedily. On the other hand, the negative effects of information technology, such as bullying and calumniation on social media have become social problems for more than twenty years. The education of information ethics has been introduced to schools in order to solve these problems in Japan. However, the problems haven’t been solved yet. Then, the national curriculum standards of elementary and junior high schools stated that the education of information ethics should be brought into the moral instruction in 2008. This requested us to develop a teaching method of moral instruction to educate students in information ethics. Therefore, the theoretical framework of the information ethics was set up, and I established a new judgment model of information ethics. I assumed that ambivalence, the state of contradictory feeling or emotion, exists behind the three types of knowledge and that ambivalence affects inappropriate judgment related to information ethics. Therefore, a teaching method with the aim of overcoming ambivalence should be developed using the structural method. From now on, cooperation with parents is essential to enhance the education of information ethics. I conceived something available to help cooperation with parents. Recently tablet PCs have been brought into the school. Then, I devised the procedure of blended learning. As a result, I developed three steps: 1) Students learn the introduction part of moral instruction in school and learn how to use the tablet PCs. 2) Students take the tablet PCs home and discuss the learning material on the tablet PCs with their parents. 3) Students learn the conclusion part of moral instruction again in school. In order to assess the effectiveness of the lesson, blended learning was practiced on 4rd grade elementary school students. As a result, it was suggested that blended learning was fairly effective in educating the students in information ethics.
The use of fuzzy in determining the potential entrepreneur
Authors: Deliana Y , Djuendah E , Suminartika E , Wulandari E , Trimo L , Tuhpawana  , Kusnadi
Published: November 2019

Unemployment in Indonesia both in the village and in the city from year to year increase, because the number of workers who are not absorbed, and entrepreneurship is one solution. There are so many traits an entrepreneur must have to be successful, including risk taker, persuader, ambitious, skill, lead, and others. This entrepreneurial group has several criteria. Entrepreneur with high potential for success is to have eight qualities: reliable, broad network, training, serving, managing, experiencing, seeing opportunities and cooperation. Entrepreneurs who have the potential to succeed have five of the eight properties and low entrepreneurship has three of the eight properties. This research was conducted in Surian Subdistrict of Sumedang District with sample of 105 people taken at random. The purpose of this study is to determine entrepreneurship that has the potential for high success, medium and low. In addition to determining the constraints of becoming a successful entrepreneur. The results of research useful for aspiring entrepreneurs is to detect the odds of success in business, so it can determine the direction in developing the potential it has.
The contribution of friendly character through cooperative-learning model with example and non-example types (CLM-ENET) on energy concepts
Authors: Ningsih S S , Mustadi A
Published: November 2019

In the Curriculum 2013, character education is likely needed by primary students to realise the benefits of the 2045 gold generation, including 4C competencies; one of which is communication skills. The aim of the research is to analyse the contribution of cooperative learning model with example and non-example types (CLM-ENET) in the primary education level on the energy concepts. The research has already been conducted through Classroom-Action Research (CAR) in the one of fourth-grade students of Sleman, Yogyakarta. The data has been collected by using observation, interview and documentation techniques. The quantitative and qualitative data have ever been analysed via descriptive statistics and students responses regarding to the friendly characters. The research result reports that the implementation of CLM-ENET is able to improve students’ friendly characters on energy concept. Students have already given and listened to opinions in their classroom-discussions when they discussed and exemplified about energy conceptions and the formed-changing of energy. In conclusion, the implementation of CLM-ENET is able to improve primary students’ friendly-characters on energy concepts.
Mathematical connections process for elementary school students in problem solving of statistics
Authors: Astari E , Marsigit
Published: November 2019

This study belongs to the descriptive qualitative research which aims to describe the process of mathematics connections of grade 5 primary school students with high mathematical ability and low mathematical ability in problem solving of simple statistical. Subjects in this study were grade 5 students in SD Negeri 42 Pekanbaru each having different levels of mathematics ability, that is high and low. The process of mathematical connection in question is the student’s steps in connecting mathematics. Connection aspects observed in this research are (1) integrating information; (2) making connections within and across mathematical domains; (3) deciding which mathematical tools to use to solve problems; (4) solving nonroutine problems. Data analysis of the students’ mathematical connection ability use triangulation method technique that is test method and interview method. The results show that 5th grade students at SD Negeri 42 Pekanbaru were not familiar with the problem because overall the students mathematical connection skills were classified as low. So, it is very necessary to apply learning strategies that can improve student’s mathematical connection skills.
Instrument design of students self-regulated learning in statistics course
Authors: Cahyawati D , Wahyudin  , Prabawanto S
Published: November 2019

The purpose of this study was to obtain an appropriate and valid instrument for measuring students self-regulated learning in a statistics course. The first step was reviewing the definitions of self-regulated learning from some relevant references. The second was writing an instrument blueprint. The third was asking some expert judges to examine the instrument validity. The next step was compiling the statement items as the initial instrument design. Then the initial instrument was used to collect the self-regulated learning data from students in higher education. Those data were processed and analysed using exploratory factor analysis. The result was the final instrument which consists of 19-items with nine strategies that were grouped into five factors. The Factor-1 was fit into a goal, planning, and organizing strategies which had 7-items; The Factor-2 was fit into a structuring in physical and mental environment (3-items); The Factor-3 was fit into a seeking information (3-items); The Factor-4 was fit into a seeking assistance and rehearsing (3-items); and The Factor-5 was fit into a self-consequence and self-evaluation (2-items). This final instrument could be used as an appropriate and valid instrument for measuring students self-regulated learning in a statistics course in next study.
Improving Students’ mathematical creative thinking ability through problem-based learning
Authors: Supianti I I , Wahyudin  , Kartasasmita B G , Nurlaelah E
Published: November 2019

Creative thinking ability is one of the capabilities needed to face various situations and problems in life, students should have this ability. This study aims to know the effectiveness of the use of problem-based learning method in improving students’ creative thinking ability. This study used a mixed method research with explanatory sequential design. This method began with the use of quantitative methods by implementing pretest and posttest to find out the average normalized gains of the students’ creative ability, and then followed by interviews to find out more about their experience in using problem-based learning and its effectiveness in improving the ability of creative thinking. The result is an increase of students’ creative thinking ability by using problem-based learning model, with mean pretest rate (19.9) and posttest (71.4), and normalized gain score of 0.856, the increase is in high category. Interview results show that problem-based learning is useful and can accommodate creative thinking ability, as it also provides flexibility to improve other cognitive abilities.
How good pre-service mathematics teacher in reading mathematical proof?
Authors: Noto M S , Priatna N , Dahlan J A , Setiyani S
Published: November 2019

Mathematics learning at the college has demanded pre-services mathematics teacher to have high-level mathematical skills including mathematical proofs. Several studies have focused on improving these abilities, but very few focus on the ability to read mathematical proofs. Though this ability that is needed by students in learning mathematical proofs. The purpose of this study is to analyse the ability to read mathematical proofs of students. This research is qualitative research, data obtained through interview and test. There were two problems in geometry given to three students with different abilities. The results show that two of the three students have good the ability to reading the mathematical proof and one student has the ability to reading proof that is lacking. Even though the three students have high mathematical initial knowledge. It can be concluded that students have good the ability to reading proof.
The different way of understanding and way of thinking between gender on the problem the linear equations of two variables
Authors: Bakar M T , Suryadi D , Darhim D
Published: November 2019

This article discusses about way of understanding and way of thinking college students between gender in solve math problems. A way of understanding is a cognitive product of a mental act perform by someone, and way of thinking is a cognitive characteristic of a mental act. The mental act is obtained by observing their statements and actions. Open interviews conducted by researchers after watching the learning video and check the college student works. This research uses phenomenographic approach. Rusdi and Ira are prospective elementary teachers who have equal ability of between gender in solving four problems related to the linear equation of two variables. The results of this study revealed that female college students tend to relate previous concepts to problems on the subject, solution representation more than one way, and way of thinking appear are to use empirical solutions and tend to follow frequently used patterns. While the male college students answered practically, that is using the clue of the question to obtain a solution, and way of thinking appear are to as non refential symbolic. This implies that way of understanding college students depends on heavily on the characteristics of their way of thinking.
Reflective Abstraction in Matematics Learning
Authors: Wafiqoh R , Kusumah Y S
Published: November 2019

The aim of this research was on how the students’ reflective abstraction worked in mathematics learning. This research was qualitative research with case study research design. In Mathematics learning, before the concept of learning material is related to another concept of learning material, the students are expected to have good Reflective Abstraction capability. In Mathematics learning, if a student has good Reflective Abstraction capability, the student will not find difficulty in Mathematics learning which are the difficulty in comprehending the material learned, the difficulty in comprehending and doing tasks given by the teachers, and the difficulty in learning other Mathematics learning materials. The result of this study were, on the process of Mathematics learning, students’ reflective abstraction was needed especially when the students had to solve mathematics problems. The students’ reflective abstraction level might be different between one and another depending on the level of problems and the concept comprehension that the students had.
Learning obstacles on the concept of function: a hermeneutic phenomenological study
Authors: Septyawan S R , Suryadi D , Nurjanah
Published: November 2019

The meaning of a mathematical concept especially function, which formed by students, is subjective in nature and has its own interpretation. Therefore, this reality is important to examine further. This study aims to explore the learning obstacles on the concept of function based on the students’ meaning of the concept and how students acquire as well as construct the meaning related to their experiences. This is a qualitative study with uses a hermeneutic phenomenological approach involving 65 10th grade students who have learned about function. The data collected through a test and interview. The interviews were transcribed and then conducted in-depth analysis to identify the learning obstacles possibility. The results of this study showed that the concept of function is meant actually as a correspondence between two elements; there is the meaning of function inconsistency; and the meaning of function that tends to be partial. On the other hand, there is a tendency that students acquired and constructed the concept of function are limited on what they’ve learned during the classroom. Based on the results of this study, it can be concluded that in general there are learning obstacles on the concept of function includes epistemological, ontogenic, and didactical obstacles.
Students’ mathematical thinking and their learning style
Authors: Delima N , Rahmah M A , Noto M S
Published: November 2019

The purpose of this study is to describe the students’ mathematical thinking based on their own learning style. The second objective of this research is to find out which one of the learning styles which has the highest mean score of the students’ mathematical thinking. In addition, this study also aims to find out whether there is a relationship between the students’ mathematical thinking with the learning style they have. Based on the result of research, the students’ mathematical thinking mostly in the medium and high category. Meanwhile, the dimension of learning style possessed by the majority of students is an assimilating learning style. Students with moderate and high students’ mathematical thinking categories, have an assimilating learning style. The mean score of the highest students’ mathematical thinking test is obtained by group of students with converging learning style. Although there is a difference in the statistical description, but the relationship between students’ mathematical thinking with their own learning styles is not significant. Nevertheless, the knowledge of the description of these two variables can serve as a good enough reference for determining the students’ self-development direction in the future.
Reflective Inquiry: Why Area is Never Negative?
Authors: Hanifat A F , Suryadi D , Sumiaty E
Published: November 2019

Reflective Thinking is an important process for an educator to be more professional. Educator can have reflective thinking with doing reflective inquiry. The reflective inquiry has a doctrine, that we not receive immediately something into information, but it’s requires examined and proven to be accepted as information. Information that examine in this inquiry is statement about area is never negative. A deep inquiry to prove that area is never negative lead to a re-reconstruction of the belief system within self, thereby generating new perspective and providing alternative solution to answer why area is never negative? Although it’s not clearly defined that area is never negative, why people accept it as a common sense? What underlies that area is never negative, even teacher itself don’t know the reason? Doesn’t teaching without understanding is consider as irresponsible action to student? Worried with this condition researcher try to figure it out and prove area is never negative with relation between measure, metric, dimension, length, and area in real set. Measure is foundation in this relation, with measure defined non-negative, causes metric and dimension defined with non-negative value. Resulting length as measure in dimension one is non-negative and proved that area is never negative.
The challenge of implementing STEM for senior high school students in the city border of Jambi
Authors: Syarkowi A , Hendri M
Published: November 2019

The purpose of this study was to describe challenges of implementation of STEM learning for senior high students in the border of the city in Jambi. Case study research design was used for this research. The STEM project which used was a simple telescope. A teacher and 35 students were observed along the learning process and then 5 students who have the problem in learning and the teacher were interviewed after stem learning done. This study finds if to implement STEM learning in this typical area was quite challenging. The main problem was how to manage a class with low motivation for learning. The other challenge was to find ingredients and component for the project. However, implement STEM for teaching and learning in this area was very possible
Facilitating of fourth grade student’s problem solving skills on friction
Authors: Gumala Y , Suhandi A , Syaodih E , Maftuh B , Ningsih A R , Afiffah R N , Qonita  , Handayani H , Hermita N , Samsudin A
Published: November 2019

This research purposes to designate students’ problem-solving skills on friction concerning elementary level through experiential learning. The indicators of problem-solving skills applied in this research were the indicators convinced to the problem-solving skills on force and impulse. A descriptive-qualitative design has already been contented to collect data from fourth-grade elementary students in one of school in Bandung Barat Regency (37 participants: 9-10 years old). The instrument which is developed formed essay with the interview process. The result appearances that every single characteristic of problem-solving skills has been developed and described such as identification, arguments hypothesis, reasoning and alternate solution. To summarize, the experiential learning is able to designate the 4th-grade elementary students’ problem-solving skills on friction.
Effectiveness problem-based learning (PBL) with reading infusion strategic to improving scientific literacy for high school students on topic global warming
Authors: Nasution I B , Liliawati W , Hasanah L
Published: November 2019

The scientific literacy is an important skill to be provided to students as effort of preparing citizens who are able to compete in the 21st century. The scientific literacy has become the main goal of physics learning. However, PISA results show that the scientific literacy of Indonesian’ student is lower compared to other countries. The aims of this study is to comparing effectiveness PBL with reading infusion and only PBL to improving students’ literacy. The design research of this study was quasi experiment method with pretest-posttest non-equivalent control group design. The subjects of this research consisted of 44 students of XI MIA at a High school in Bandung. The students were divided into 2 groups. The data collection was conducted through scientific literacy instrument that was developed before this study. The data was analyzed using n-gain, T-test and effect size. Results shows that the scientific literacy in experiment group is higher than control group significantly and the implementation PBL with reading infusion strategy has large effect to improving students’ scientific literacy. The results clarify that PBL with reading infusion strategy in physics learning is effective to improving scientific literacy students at high school.
Use of geoel ectric practicum module for physics education students
Authors: Agustina R D , Chusni M M , Malik A , Dirgantara Y , Samsudin A
Published: November 2019

The purpose this research development geoelectric module in supporting material of Earth and Space Science lecture. Method this research used Research and Development. The design research that includes analysis, design, development, implementation, and evaluation. The subject of this study where student of physics education on Program Studi Pendidikan Fisika, UIN Sunan Gunung Djati. Feasibility of geoelectric module on expert search result and field practitioner. The result show that the geoelectric module meet the standard of the feasibility aspect of the teaching concept.
The characteristics of development teachers’ pedagogy competencies of electromagnetics test
Authors: Hakim L , Sinaga P , Setiawan A
Published: November 2019

The aim of this research was to evaluate the faces of the pedagogy competencies test and quantity mistakes rendering to classical test theory and item response theory. The test was constructed on the fundamental concepts and essential content of the electromagnetics, with an orientation to the pedagogy competencies physics teacher. The pedagogy competencies designate is the competencies integrated into teaching and learning electromagnetic. The research method is a mixed-method with embedded experimental models. The analysis was based on 40 answers of pre-service who have taken training teaching in school (PPL) courses at the Physics Education Department. Based on classical test theory indicates that 15 test items were analyzed, 12 items were good quality with reliability index is 0.72. As of information function and standard error measurement of item response theory, the conclusion of this evaluation is that the model 3PL is better to use when evaluating the test.
Apply model of teaching levels of inquiry for identifying experimental skills on solar system matter in the middle school
Authors: Nurjanah A , Utari S , Ramalis T R , Rusdiana D
Published: November 2019

Apply model of teaching Levels of Inquiry in middle school level can identify experiment skills use the similarity from every stage in Levels of Inquiry process according to ten aspect of experimental skills that is adopted from Brotosiswojo and Richard J. Rezba. There are observation, making prediction, knowing variable, formulating hypotheses, operating variable, designing experimental procedure, collecting data, analyzing data, and making conclusion. This research is applied in the one of the middle school in Lembang, West Java with solar system as the matter. The research design used one group pretest-posttest design to 30 seventh-grade students. The learning process used semi-experimental phenomena because solar system matter in the middle school does not deliver much mathematic analyze. Collecting data from three meetings with different sub matter (time zone, moon phase, and solar eclipse). Supported instrument is student worksheet assessed using Lati criteria (very poor, poor, fair, good, and excellent). Identifying experiment skills can use its model and it can enhance from first to third meeting with the result is poor, fair, and good.
University student’s self-reflection ability on thermal insulation concept
Authors: Nurjannah N , Setiawan A , Rusdiana D , Muslim M
Published: November 2019

We have already probed students’ self-reflection ability on thermal insulation concept. Self-reflection is needed to investigated because it influences the development of students’ conceptual understanding. The thermal insulation problem has been given to 20 preservice physics students who have been enrolled in the Introductory Physics I. Qualitative way has chosen to analyze the test. The data analysis has mainly fixated on students’ self-reflection on thermal insulation problem. Stand on data analysis, it can be decided that students’ self-reflection ability on thermal insulation concept is still poor category.
Case study: investigating of eleventh graders’ translating among modes of representation ability on linear motion
Authors: Rahmadewi B , Setiawan A , Siahaan P
Published: November 2019

The purpose of this study is to describe the profile of students’ translating among modes of representation ability on physics. The ability to represent information into verbal, graphical, picture, table and mathematical representations in order to help students define suited physics’ concepts on solving physics problems. Participants included 28 11st grade students in a senior high school in Bandung. The sampling technique is random sampling. This study used description method to describe the profile of students’ translating among modes of representation ability. The findings showed that students’ translating among modes of representation ability were classified in medium category with 54.44% of mastery. The highest average score on students’ ability to represent picture representations into mathematical format was 69.60% from its ideal maximum score. Whilst students’ ability to represent pictorial format into graphical reached 25%. It can be concluded that students’ translating among modes of representation ability is insufficient category.
The analysis of tenth grade LMM on work and energy
Authors: Putri N , Samsudin A , Nugraha M G , Fratiwi N J
Published: November 2019

The purpose of this research was to intimidated LMM (Learners’ Mental Model) of work and energy. The mental model can be used to considered more extremely apparatus of misconceptions. The research method is a case study with descriptive quantitative analysis. The samples are 30 tenth grade students (14 boys and 16 girls, their ages were middling 16 years-old) at one of senior high school in Bandung. The research sample used cluster random sampling technique or random class. LMM was analysis through two-tier test in the form of open-ended questions as many as 5 questions. The data investigation was approved purchasable in two stages. In the first stage the analysis learners level of understanding and in the second stage the analysis learners model of understanding. The result illustrations that mental models have been identified in the three categories, that are, 1) Scientific 26,7%, 2) Synthetic 16%, 3) Initial 57,3%. In conclusion, mental model of the initial category is higher than other categories.
Improving students’ conceptual knowledge on optical device materials with computer simulations
Authors: Rahmadani S , Samsudin A , Danawan A , Kaniawati I , Suhendi E
Published: November 2019

One of the factors causing the low level of student’s conceptual knowledge on optical device materials is the difficulty of students to observe the shadow formation process so that one can see an object. Students difficult to understanding the function and way of working the parts of the eye. Therefore, it is necessary to develop computer-based instructional learning media on optical device materials. The development of learning media using development method with the sample of research as many as 23 high school students. The instruments utilized to determine the increase of students’ conceptual knowledge were pre-test and post-test in the form of FTOPT (Four-Tier Optic and Photonics Test). After using Optics Simulation (OpSi) in physics learning, student’s conceptual knowled2,5ge of optical device material has increased as indicated by the normalized gain  = 50,93% with the medium category.
Effectiveness of the use of developed teacher’s book in guiding the implementation of physics teaching that provides science literacy and instill spiritual attitudes
Authors: Suhandi A , Samsudin A
Published: November 2019

Research and development to produce Physics teacher’s book products to guide the planning and implementation of Physics teaching that can provide scientific literacy and instill students’ spiritual attitudes has been carried out. Usage test of the developed teacher’s books have been carried out in one of the high schools in West Java. Subject in this study is one of physics teacher and 40 students. The focus of the research is to get an overview of the effectiveness of the use of the developed physics teacher’s books in guiding teachers to carry out physics learning that can improve the science literacy and spiritual attitudes of students. The instrument used in this study are the science literacy test and the spiritual attitude scale respectively. The effectiveness of the teacher’s book in guiding the teacher to carry out physics teaching is determined based on the number of students who achieve a high increase in science literacy and spiritual attitudes. The results of the study show that the use of the developed teacher’s books has high effectiveness in guiding teachers to carry out physics learning that can improve science literacy and moderate effectiveness in instill a spiritual attitude.
K-12 students’ misconception ability on global warming: a case study
Authors: Satriadi S , Liliawati W , Hasanah L , Samsudin A
Published: November 2019

A case study is a research design to identify misconception about high school students on global warming. Diagnosing misconception process is important factor to help teachers overcome their learning problems. The participants are 100 students with 43 males and 57 females of the third grade students of senior high schools in Bandung. The data has been collected by distributing diagnostic test items in the form of three tier test. The study indicates that there are several misconceptions related to global warming such as (1) Global warming is caused by ozone layer depletion, (2) The greenhouse effect is not a natural but man-made phenomenon, (3) Carbon dioxide (CO2) which has been erode the ozone layer in the stratosphere, (4) Greenhouse gases increase due to the depletion of the ozone layer, and (5) The ozone layer is the layer involved in the process of the greenhouse effect. In conclusion, the results of this study established that the diagnostic test is able to analyse the students’ misconceptions as well as categorize the level of students understanding toward the global warming; understand the concepts, misconceptions, or don’t understand concepts.
Identification of the causes of misconception on the concept of dynamic electricity
Authors: Halim A , Lestari D , Mustafa
Published: November 2019

This study aims to find out the causes of misconceptions on the high school students in the subject matter of dynamic circuit through mixed method. The population of this study is all students of class XII SMAN 2 Banda Aceh. The sample was chosen by random sampling, so that there were 21 students for the control class and 21 students for the experimental class. Data collection was done by questionnaire technique in the form of questionnaire about the cause of misconceptions which is called the Instrument for Identifying the Causes of Misconceptions (IICM) consisted of 35 items was developed by researchers with validity and reliability indices respectively 0.75 and 0.85. The results of data analysis show that the largest percentage of causes of misconception is by students and by context. Thus it can be concluded that the cause of misconception among high school students for dynamic electrical circuitry is caused by the student’s self as well as the context. The causes of misconceptions in students are more at the stage of cognitive development of students and in most contexts caused by feelings of pleasure/displeasure or free/depressed.
Eleventh grade students’ conception analysis: a case-study on heat transfer
Authors: Syamsiah E N , Maknun J , Syamsudin A , Muslim M , Hasanah L , Suhandi A
Published: November 2019

We have precisely conducted research to identify students’ conceptions on heat transfer. A case study has been implemented by using purposive sampling technique. The research participants are 11 males and 24 females of eleventh grade students. The largest percentage of students’ conception is in the category of misconception, such as: (1) heat transfer is taking place while system has reached thermal equilibrium, so temperature difference still exists; (2) Objects that absorb heat more quickly, will emit heat radiation more slowly; (3) In conduction, heat flows because it is carried by moving electron of a medium; (4) In convection, the rate of convection goes faster as the water boils.
Enhancing student creative thinking skills through HOTVL design
Authors: Nur A U , Setiawan A , Ramalis T R , Nurhayati
Published: November 2019

The purpose of this study was to investigate the creative thinking skills improvement through Higher Order Thinking Virtual Lab (HOTVL) learning. This research used a quasi-experiment method with pre- and post-test group design. 57 students took part in this research from eleventh grade student in a senior high school which is divided into two classes, experiment and control group. Student of experiment group using HOTVL experiment design and control group using lab virtual verification design. Students’ creative thinking skill was measured using tests of creative thinking skill in form of nine essay question about global warming. Learning activities in this research completed with a worksheet and lab virtual learning multimedia. This research using item response theory (IRT) to analyse the data. The result showed that the percentage of students’ latent variable (score) of creative thinking skill in HOTVL class was higher than the percentage of students’ score in lab virtual verification.
High Performance Secondary Index Design for Complex Queries in Smart Grid System
Authors: Jiafeng Qin , Shitai Shu , Longlong Li , Chengqi Li , Demeng Bai , Wenjie Zheng
Published: November 2019

Since the traditional relational database is difficult to cope with the massive data and properties produced by thousands of sensors in the smart grid, the HBase database of the new large data platform, as a column oriented key value storage database, has gradually become the mainstream large data platform database. Though HBase can support large data volume, but it is still difficult to cope with the demand of high frequency and short response time in power grid data analysis. In this study, we proposed a query oriented two level index scheme that can speed up the query. The experimental results show that when the two table connection queries are involved, our scheme can provide a minimum of 1.026 to the maximum 4.761 times the acceleration ratio compared to the classic two level index, when it involves three table connection queries, Our scheme provides a minimum of 1.797 to a maximum of 8.581 times the speed ratio of the classic two level index scheme. After further optimization, the scheme can also save much of the storage space of the index table. The two level indexing scheme proposed in this study has a good effect in terms of query performance and storage efficiency.
Comprehensive Evaluation of Two-side Voltage Sag based on Local State Variable Weight and Complex Correlation Coefficient Method
Authors: Tianhao Zhang , Lijun Tian , Fangheng Zhang
Published: November 2019

The severity assessment of voltage sag is one of the important basis to measure power quality.At present, voltage sag assessment is mostly based on system or load, lacking of unity on both sides.The evaluation indexes of the voltage sag on the side of the system are divided into the first level and the second level.The load-side evaluation adopts the equipment failure rate based on the comprehensive tolerance curve of sensitive equipment, and the failure probability model is based on the energy function.The complex correlation coefficient method is used to synthesize the indexes of system side and load side to avoid the excessive evaluation caused by the repetition of information in the evaluation.At last, an example analysis is carried out on the proposed method based on the measured data, which verifies the correctness and superiority of the method.
Electric Field Simulation of Equipotential Live-line Work in 500kV Cup-type-tower
Authors: Guo Tao , Wang Shichun , Xu Lianggang , Shi Hongyun , Liu Yongxin
Published: November 2019

As an important part of the power grid, the safe and reliable operation of overhead transmission lines is of great significance. In order to ensure the reliability and continuity of power supply in power grid, the overhaul mode of live-line work is usually adopted. At present, there is little research on live-line work of overhead transmission line overhaul arrester at home and abroad. In order to ensure the safety of live-line work operators, this paper models and simulates live-line work of overhauling surge arrester with support clearance in 500 kV cup-type-tower. The distribution of electric field on the surface of live-line work operators under this line structure is calculated and analyzed, which can provide reference for the personal safety of live-line work operators.
Application of Improved BPNN Algorithm in GIS Insulation Defect Type Identification
Authors: Feng X Y , Hu X L , Yong J , Yang B , Sun X B , Duan Y B , Meng H L , Xu Y P
Published: November 2019

In this paper, a new BP neural network has been built with GA algorithm, which possesses high effectivity, parallel processing ability and global search feature, in order to overcome the original shortcomings such as the low convergence rate and the confusion of local minimum points. Ten parameters of partial discharge characteristics are obtained as input of BPNN to identify four typical insulation defect physical models designed in this paper for the purpose of measuring the recognition accuracy of the improved BPNN. Experiments show that the improved BPNN has a better performance of convergence speed and recognition accuracy than that of adaptive momentum BP neural network.
Study of Temperature Field and Ampacity of 110kV AC Submarine Cables under Different Laying Conditions
Authors: Chen Zhenxin , Le Yanjie , Liu Heng , Yang Fan , Hu Wenkan , Hu Kai , Li Jinxian , He Tingting
Published: November 2019

Submarine cables have complicated structures and high production process requirements. In order to make sure the submarine cables to operate safely and reliably, this paper takes into account how the different laying conditions of submarine cables affect the maximum allowable ampacity. A 110kV YJQ-1×500 XLPE submarine cable is taken as the research object, based on the finite element method, the electromagnetic-thermal coupling models of the submarine cable laying in underwater soil, seawater and pipeline is established respectively in Comsol Multiphysics to study their thermal field and ampacities. The results indicate that the laying conditions would affect the cables’ heat dissipation, submarine cable lays in seawater has the highest ampacity and lays in the pipeline in landing section of the cable has the lowest ampacity. Moreover, the variation of temperature of seawater would also influence the ampacity of the submarine cable.
Energy Efficiency Optimization for Ubiquitous Power Internet of Things
Authors: Jijun Wang , Min Xiao , Yongqiu Chen , Mingsheng Xu
Published: November 2019

In the research of internet of things, considering power allocation of base station from the perspective of energy efficiency (EE) is very meaningful for ubiquitous power internet of things (UPIoT) optimization. In this paper, the EE of UPIoT was analyzed and a new method for internet optimization was proposed by adjusting the small cell transmits power. First, the UPIoT was modeled by two-tier homogeneous Poisson point process (PPP), and the coverage probability of base stations in each tier was derived. Second, according to the definition of EE, and the closed-form of EE was given by deriving the total power consumption and total throughput of UPIoT respectively. At last, the impact of the small cell transmission power on the EE of UPIoT was analyzed, and a small cell power optimization algorithm was proposed to maximize EE. Simulation results show that, the transmission power of cell has a significant impact on the EE of UPIoT. Furthermore, by optimizing the transmission power of small cell, the EE of UPIoT can be improved effectively.
Features of heat transfer with cooling by dispersed flow
Authors: Mirnov S V , Komov A T , Varava A N , Dedov A V , Lyublinski I E , Vertkov A V , Zakharenkov A V , Smorchkova Yu V
Published: November 2019

Two types of heat transfer were established during cooling by a dispersed flow, depending on the values of the mass flow rate. Equations are proposed for calculating the heat transfer coefficient.
Increase of maneuverability of nuclear and geothermal power plants by hydrogen-oxygen complexes
Authors: Schastlivtsev A I , Borzenko V I , Dunikov D O
Published: November 2019

We present results of feasibility analysis of hydrogen-oxygen complexes for base load power plants. To increase flexibility of nuclear and geothermal power plants it is proposed to produce hydrogen and oxygen by excess power and use the gases in hydrogen-oxygen steam generators to produce high temperature steam and provide additional power during power ramps. It is possible to decrease the time of power ramp from 20% to 100% of nominal capacity from 13-15 min to 1.5, while the main steam generator increases capacity with the rate 5-6%/min. Taking into account a rare need in such a big power ramps and low capital intensity of hydrogen-oxygen steam generators, the total increase of capital investments in a nuclear plant should be ca. 1%.
Isotopes of water molecules in a glow discharge in mixtures of helium with H2O and D2
Authors: Bernatskiy A V , Kochetov I V , Lagunov V V , Ochkin V N
Published: November 2019

The article presents the results of theoretical and experimental research on the concentrations of water isotopomers (H2O, HDO, and D2O) in plasma of a DC discharge in mixtures consisting of helium, molecular deuterium, and water vapor. Dependence of the isotopomers concentrations on the initial mixture composition is described. The measurements were performed using tunable diode laser absorption spectroscopy (TDLAS). Theoretical results were obtained with the use of a homogeneous kinetic model. The model included the balance equations for charged and neutral particles and the Boltzmann equation for the electron energy distribution function in the two-term approximation. The experimental and theoretical values of H2O and HDO concentrations were compared and showed good agreement.
Calculation of ionized chemically nonequilibrium flow around a reentry module
Authors: Molchanov A M , Popov V E
Published: November 2019

A method for calculating a hypersonic ionized flow at the entrance of the reentry module into the Earth’s atmosphere has been developed. The mathematical modeling of such a flow was performed using a system of equations, which includes the equations of the continuity of components, the equation of momentum, the equations of total energy, vibrational energy, and electron energy. Chemical reactions and ionization reactions were taken into account. The vibrational temperatures of diatomic molecules and electrons were calculated. Calculations were made for various flight altitudes (60-85 km) at free-stream speeds from the first to the second cosmic velocity. The results of computations according to the proposed methodology are in satisfactory agreement with the experimental data and the computation results of other authors.
Research on structure of a ash-slag pulp and its influence on pipelines’ attrition of a thermal power plants’ hydraulic ash removal system
Authors: Chugunkov D V , Seyfelmliukova G A , Kuzema V P , Bogdanova A E
Published: November 2019

One of the key characteristics, affecting intensity of slurry pipelines’ attrition, is the abrasiveness of the transported material. It depends on the content of silicon oxides, a form and fineness of ashes particles. According to input data, it is figured out that different types and grades of coals with different chemical properties, fractional composition and coal fineness were incinerated at different times on HTPP-3. Because of it the attrition is result of different types’ transportation of ashes with various abrasive properties, with various fineness, density and chemical composition. Calculation results of pulp pipelines’ specific attrition at transportation of ash-slag pulp on HTPP-3 are given in this work.
Neutron yield from Z-pinches at generation of the power-degree spectrum of fast deuterons
Authors: Vikhrev V V , Yu Frolov A , Yu Chirkov A
Published: November 2019

The neutron yield from the plasma of deuterium Z-pinch is analyzed with a power-law spectrum of fast deuterons in the energy range from several hundred keV to several MeV. The influence of the typical energies of fast deuterons and the exponent index of the spectrum is considered. The efficiency of neutron generation is estimated by the ratio of the neutron yield to the average deuteron energy. It was shown that when generating fast deuterons with energies of the order of 1 MeV, the reaction rate is much higher than for Maxwellian plasma with a temperature of the order of 10 keV.
Experimental investigation of thermophysical properties of rhenium near its melting point
Authors: Senchenko V N , Belikov R S
Published: November 2019

An experimental technique of millisecond electrical pulse heating was used for experimental investigation of Re near its melting point. Experimental data on the specific enthalpy and thermal expansion of rhenium at the temperatures close to the melting point were obtained during the experiments.