bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation through a viscoelastic surfactant of a fracable hydrocarbon-containing formation
Authors: Kuchin Viacheslav , Dvoynikov Mikhail , Nutskova Mariia 
Published: May 2020

AbstractIn this paper water cut of well products problem is considered. To solve this problem it is proposed to use a technology of water inflows isolation during the drilling process developed by the authors. Not only does our approach stimulates the production of hard-to-recover hydrocarbons but it also protects local water and undisturbed geological formations against the impact of hydraulic fracturing operations. This approach also enables higher well potential due to a longer service life of the wellbore. The use of a device-pressure regulator with synchronous injection of the developed blocking fluid is presented. Mathematical modeling of the experiment was performed, aimed at determining the dependence of the change in pressure drop in the annular space of the well on the flow conditions of the blocking composition with a device installed in the bottom hole assembly that will effectively apply the controller device, taking into account the drilling parameters of a particular well. The novelty of this approach lies in the fact that this work offers an aquifer isolation technology, which suggests applying a pressure regulating device, and provides a layout of a blocking viscoelastic system.
Coverage Based Test Suite Minimization using UML Behavioural Diagrams
Authors: Gupta Rashmi , Jaglan Vivek 
Published: May 2020

Abstract
There is an important role of software systems testing in the software development cycle. The software testing is used to reveal errors in software which enhances overall quality and efficiency of the software. The approach followed for software testing should be such that it can detect maximum number of errors in minimum time which can lower the effort spent in maintenance phase. Coverage criteria are very important to analyze test cases which can be useful in fault coverage and minimizing the test suite. As it takes a lot of time in the software system testing, so minimizing the test cases can help in minimizing the overall effort required to lower the testing time. Test cases should be selected such that they are covering maximum of activities, basic path and conditions present in the graph and taking less time while executing.
Selection of Optimal Tire and Design Optimisation of Steering System for a Formula Student Race Car through Tire Data Treatment
Authors: Swamy Varsha S , Karan Shivayogi H G , Rajesh Mathivanan N 
Published: May 2020

Abstract
Selection of tires plays a crucial role in Vehicle Dynamics, which is important to design the steering and suspension system. An attempt is made to select the most optimum tire for lateral performance by using the tire data acquired from Tire Testing Consortium. Parameters including the tire’s lateral grip, cornering stiffness, cornering stiffness coefficient, camber stiffness, and lateral frictional coefficient have aided this selection. The tire is modelled using the Pacejka Magic Formula where the lateral and aligning coefficients are found, and used to get pneumatic trail, a parameter not provided in the raw data. The novelty of the work is seen when the selected tire is analysed to set the camber, pressure, and caster using the Design of Experiments method, without the need for building and testing a car. Making the best use of the tires’ forces and moments, the steering geometry is designed for a target range of radii by operating the tire slip angles at its optimum value. Further the influence of the change in toe angle on the Ackermann percentage is examined. Steering moment, calculated using the aligning moment curves of the tire, is applied to the steering column to conduct finite element analysis.
A Radial Basis Function Neural Network Based Approach to Mitigate Soiling from PV Module
Authors: Kumar Sujit , Kamal Neel , Gaur Aditya , Pathak Mohit , Shrinivas Kumar , Singh Priyanshu 
Published: May 2020

Abstract
Solar power is available in abundance and is free of cost but despite this fact photovoltaic (PV) systems are not reliable as the efficiency of PV module is still not up to the mark. Amount of sun light absorbed by the module is the fuel for the PV modules, there are many factors which play a vital role such as front surface reflectivity, solar beam incidence angle and the most important is the transmissivity of the front surface. Objective of this paper is to examine the function of a neural network based model of a module to mitigate the soiling and improve the accuracy of dust prediction over the module and enhance the efficiency which was degraded by soiling. One of the techniques in artificial intelligence named, radial basis function neural networks (RBFNN) is utilized here to predict the dust data by reading the data of solar irradiance, module temperature, PV voltage, current and power and generates the control signal to the windshield wiper motor that drives the wiper to wipe the dust from the panel. A considerable measure of accessible exploratory information was utilized for the preparation of the RBFNN, and a back propagation algorithm was utilized.
Mathematical critical thinking ability of students with realistic mathematics learning innovations with ethnomathematics (PMRE)
Authors: Muslimahayati  , Dasari D , Agustiani R 
Published: May 2020

Abstract
The importance of critical thinking ability is on the demands with the current curriculum which wants students to have the ability to analyze and solve problems, especially in everyday life. However, this ability is still not explored maximally by the teacher in classroom learning. Therefore, this study examines the improvement of critical thinking ability among students who obtained the PMRE approach with students who obtained conventional learning, reviewed as a whole and reviewed according to the high, medium and low mathematical initial ability categories. This research is a quasi-experimental study with nonequivalentpre-test and post-test control-group design. The data obtained were analyzed using the mean difference test namely t-test and mann-whitney. The results showed that: 1) the improvement of critical thinking skills of students who received PMRE approach as a whole was better than students who obtained conventional learning with a moderate category 2) reviewed from mathematical initial ability, increased critical thinking skills of students in the medium category who were getting PMRE learning more better than students who get conventional learning, while for high and low students who get PMRE learning is no better than students who get conventional learning.
Design of mathematics learning in the grand mosque of palembang
Authors: Martadinata I , Somakim  , Darmawijoyo  , Araiku J 
Published: May 2020

Abstract
This study aims to describe the role of the context of the Grand Mosque of Palembang to support the mathematics learning process and produce learning trajectories to help students in understanding quadrilateral material (square, rectangle, and isosceles trapezoid) with RME approach. The methodology in this research is design research, consisting of preliminary design, design experiment, and retrospective analysis. The subjects are seventh graders of MTSN 1 Palembang. The instruments in this research are videos, documentation, student activity sheets, pre-test, and post-test. The results show that the context of the Grand Mosque of Palembang helps students to compare and connect the perimeter and area of a rectangular plane. All strategies and models that students find, describe and discuss, show how the construction and contribution of students help their initial understanding of the topic. In experience based activity, comparing and connecting the perimeter and area of rectangular plane holds an important role in transitioning from informal to formal levels.
Development of proof-based student worksheets in trigonometry
Authors: Ismerelda I , Hartono Y 
Published: May 2020

Abstract
Research has been conducted for: (1) Developing student worksheets based on valid trigonometric mathematical proofs, (2) Developing student worksheets based on practical trigonometric mathematical proofs and (3) Knowing the advantages and limitations of validation student product based on trigonometric mathematical proof developed. The research method used is research and development (R&D) with a development model developed by Rowntree, using three stages, namely: (1) the planning stage, (2) the development phase and, (3) the evaluation phase. The results of data analysis can be concluded The results give meaning that the developed: (1) is appropriate and appropriate to use, because it is in accordance with core competencies, basic competencies, indicators, objectives, scenarios of teaching and learning activities and has phases that are measurable and clearly easily understood by students and can develop Student that have been developed to meet the eligibility as a good Student, (2) both at one to one stage and small groups based on the criteria of practical use for each indicator in the practicality category on good level. (3) Excellence Developed Students can increase motivation, foster interest in learning, foster an attitude of confidence, can foster an honest attitude, increase discipline and foster cooperation among fellow students.
Students’ characters in solving higher-order thinking skill questions assisted with technology
Authors: Suci A , Aisyah N , Meryansumayeka  
Published: May 2020

Abstract
The purpose of this study was to describe students characterr in solving HOT (Higher order thinking) questions assisted with ICT (Information and Communication of Technology). Research conducted is a descriptive qualitative research. This study have 4 focus characters namely hard work, creative, thorough, and curiosity. The subject in this study is 4 students of class XI IPS SMA Srijaya Negara Palembang. Data collection in this study include tests, interview, observation, documentation, and using triangulation techniques of data collection to check the validity of the data instrument. The results of this study indicate that the most dominant character values appeared during the learning process with HOT and ICT-assisted media are the value of hard work and curiosity.
Ethnomathematics-based learning using oil palm cultivation context
Authors: Marleny A S , Somakim  , Aisyah N , Darmawijoyo  , Araiku J 
Published: May 2020

Abstract
Agriculture is a culture that has been embedded in Indonesian society. Along with the changing times, then this culture began to be abandoned and tend not to be known by the current generation. Ethnomathematics exists to bridge the gap between culture and education. The purpose of this study was to find out the mathematical ideas on oil palm cultivation and determine students’ responses in Ethnomathematics-based learning. This research uses descriptive qualitative. In this study, an assessment of the knowledge, ideas, or findings contained in the literature was carried out to provide theoretical information and interviews to oil palm companies and smallholders related to oil palm cultivation and implemented in mathematics learning. The application of agricultural activities in mathematics learning is expected to introduce and preserve agricultural culture to students and learning becomes more fun and meaningful.
Designing HOTs-oriented learning material using PMRI approach
Authors: Septiani E , Aisyah N 
Published: May 2020

AbstractThis research aims to generate higher-order thinking skills (HOTs)-oriented learning trajectories that can help students to understand the material of two-variable linear equation using Indonesian realistic mathematics approach (PMRI). There are three stages in this research, namely preliminary design, learning experiments, and retrospective analysis. The subjects in this study are eighth grade students of SMPN 46 in Palembang. Data collection techniques use observation, interviews, video recordings, pre-test and post-test, and field notes.The results of this study is the development of Hypothetical Learning Trajectory into learning trajectory with 3 activities namely identifying problems and making examples, making mathematical models, and being able to solve problems in daily life.
Mathematical modeling teaching materials using hyperthermia context
Authors: Irwansyah E , Darmawijoyo  
Published: May 2020

Abstract
The purpose of this paper is to produce teaching materials for mathematical modeling in the context of hyperthermia for students of MTs Negeri 1 Lahat. This research uses design research with the type of development study that has two stages: preliminary and formative evaluation. The preliminary phase is carried out by making product modeling and evaluation teaching materials, data obtained by validating with experts. The success criteria of this study are to obtain valid teaching material, based on input from expert review and analyzing results from one-to-one stages. Based on the results of validation with experts and student answers at one-to-one. Needed, obtained valid modeling teaching materials.
Mathematical modeling worksheet using health context
Authors: Yusherlly H , Darmawijoyo  
Published: May 2020

Abstract
The purpose of this study is to produce a valid mathematical modeling student worksheet. The method in this study uses the design research method with the type of development study. The research instrument developed was a mathematical modeling student worksheet. The subject of this study were 11th grade of senior high school student at Tebing Tinggi. The results of this study were a valid mathematical modeling student worksheet
Students’ responses on ethnomathematics based learning with the context of Kayuagung community
Authors: Sari H J , Somakim  , Araiku J 
Published: May 2020

Abstract
This research belongs to the type of qualitative research with ethnographic design, which aims to find out the mathematical ideas contained in the innate ritual or the conveyance of the people of Kayuagung, Ogan Komering Ilir district called oban yadikon rasan. And to find out learning using the context of the oban yadikon rasan. The subjects in this study were resource persons who had knowledge about the wooden yadikon oban yadikon and IX grade students in SMP Negeri 2 Kayuagung. This research generates mathematical ideas to build dimensional space 3, which corresponds to junior high school students, namely the material to construct curved side spaces in class IX. After learning by using these mathematical ideas, students in class IX.1 as the subject of this study conclude that learning is more interesting and increases students’ interest in learning mathematics. Thus ethnomathemics-based learning with the context of oban yadikon rasan agung for junior high school students, received a positive response that is more interesting and increased student interest in learning.
Developing a learning design of mathematical modelling courses on understanding basic concept of mathematical modelling
Authors: Kurniadi E , Darmawijoyo  , Pratiwi W D 
Published: May 2020

Abstract
The approach to learning mathematical modelling is an approach that focuses on mathematics learning by using the context of real world phenomena so that the use of mathematics can be used in describing a process of understanding, simplifying, and solving problems in the form of mathematical modelling in order to have deeper understanding. Therefore, undergraduate students of the mathematics education as prospective mathematics teachers in schools need to get in-depth competencies related to mathematical modelling learning. These competencies were obtained by students in mathematics modelling courses. Based on the importance of mathematical modelling courses for students of mathematics education study programs need to be made in the design of learning in the subject of mathematical modelling based on the development of questions according to the characteristics of mathematical modelling. This study aims to generate local instruction theory in mathematics modelling courses after lectures are based on designing modelling task. Therefore this research will refer to design research methods in learning by constructing the Hypothetical Learning Trajectory (HLT) which will become Local Instruction Theory in the subject of mathematical modelling. In this paper, we focussed on the first step on HLT that is the basic concept of mathematical modelling. The results of this study are forming hypotheses, developing learning designs, and testing the truth according to research design methodology.
Secondary students’ higher-order thinking skills in solving PISA- like mathematical tasks
Authors: Meryansumayeka  , Putri R I I , Zulkardi  , Hiltrimartin C 
Published: May 2020

Abstract
Higher order thinking skills have become one of the main focuses in learning mathematics based on Indonesia curriculum currently. One of the teacher’s efforts to help students to develop higher order thinking skills is to provide questions like PISA questions. This is because PISA is a test of students’ abilities on an international scale, which also serves as a benchmark for the mathematical abilities of Indonesian students. This study is a descriptive type qualitative study. It purposed to describe students’ mathematical ability especially related to their higher order thinking skills in solving tasks like PISA tasks. Six secondary students consisting of 3 boys and 3 girls with different type of mathematical abilities were involved as research subject. Data were gathered through observation, interview, and documents such as students’ worksheets and they were analyzed qualitatively. The result showed that the most dominant skill appeared among analyzing, evaluating, and creating skills is analyzing skill. Although students sometimes made mistakes in determining final answers, they indicated trying to develop their skills by solving problem categorized as analyzing, evaluating or creating problem.
Analysis of student’s proof construction on logarithms
Authors: Jessica C , Hapizah  , Scristia  
Published: May 2020

Abstract
This research is a descriptive study that aims to describe the construction of student’s proof on logarithmic material. Proof construction is the ability to construct direct or indirect proof using information provided such as definitions, principles, theorems, and assumptions in a logical and detailed manner. The research subjects were 40 students of the X-grade students of MIA 6 in Palembang 10 Public High School. The learning process is carried out with direct learning steps. The data collection technique used is a written test consisting of 3 questions. The data obtained will be corrected, grouped and analysed using evaluation of proof consisting of five categories to identify students’ understanding of the construction of proof for each questions. The results of the study stated that the construction of proof by students on logarithmic material in the X-grade students of MIA 6 in Palembang 10 Public High School was already in the K1 category. This is due students are able to provide valid general arguments and use them to construction of proof.
Developing lesson plan and student worksheet on realistic mathematics approach oriented to achievement and interest in mathematics
Authors: Sukmaningthias N 
Published: May 2020

Abstract
This study aimed to produce lessons plan and student worksheet based on realistic mathematics approach oriented to the Achievement and Interest of mathematics learning which is good quality and fulfill valid, practical and effective criteria. This study was development research. The method used in this study was the development method of ADDIE. The ADDIE development method consists of analysis, design, development, implementation, and evaluation. The result of this study shows that the lessons plan and worksheet developed have been valid, the lesson plan is in very good quality with the average score 150.33, and the student worksheet is in good quality with the average score 117.67. The lessons plan and worksheet that have been developed is practical, with very good quality based on the teacher’s assessment and good quality by student assessment. The implementation of learning activity is 98%. The results also show that lessons plan and worksheet are effective. It is shown by the improvement of achievement and interest mathematics learning of students after using lesson plan and worksheet. Achievement has high quality with average score 82 and students learning completeness percentage reaches 82%. Similarly, the questionnaire results of interest are of high quality with the average score 88.71. Therefore, the lessons plan and worksheet fulfill the criteria of validity, practicality, and effectiveness.
Analysis of students’ mistakes in solving mathematics olympiad problems
Authors: Shinariko L J , Saputri N W , Hartono Y , Araiku J 
Published: May 2020

Abstract
This study aims at analysing students’ mistakes in solving mathematical olympiad problems. The test was conducted in SMA Negeri 1 Palembang involving 40 students. The main topics are algebra, combinatorics, geometry, and number theory. The analysis is based on Newman Error Analysis. The results show that the most common mistakes are found in combinatorics and geometry. The most common mistakes analysed using Newman Error are comprehension and transformation errors. In order to solve this problem, teachers need to assign various mathematical problems. Hence, the students will have more flexibility to apply problem-solving strategies.
High school students’ mathematical modeling skills in problem-based learning (PBL)
Authors: Sakinah A R , Hiltrimartin C , Hartono Y , Indaryanti  
Published: May 2020

Abstract
This study aims to know the mathematics modeling skill in Problem-based learning (PBL) in high school. Data were collected by test method in Students grade 10 SMA Negeri 2 in system of linear equation in three variable material. Based on the results of the research analysis, 64.7% of categorized learners have excellent modeling skills, 32.5% of the categories are good and 2% are poor. That is because students do not understand the problem, even though one of the goals of mathematics learning is students can solve mathematical problems which are covered by understanding problems and modeling problems into mathematical form. To realize these learning objectives the use of appropriate learning models is an important aspect. One learning model that can be used so that students have good modeling skill is Problem-based learning (PBL). PBL has a focus learning on contextual problems, so students can understand the problem and able to make mathematical models of the contextual problems presented.
High school student’s mathematical modeling skills in open-ended learning
Authors: Damayanti U , Hartono Y , Hiltrimartin C , Indaryanti  
Published: May 2020

AbstractThis research is a descriptive study aims to determine the mathematical modeling skills of students after using the open-ended learning to algebraic arithmetic operations in class VII SMP Negeri 17 Palembang. The subjects of this study were grade VII.6 students of SMP Negeri 17 Palembang with 32 students. The learning process is adapted to the stages of the open-ended learning. On the student worksheet, the problem given is an open-ended problem. The researcher also uses problem-solving questions during the evaluation test. Data collected using tests. The results of this study indicate that the mathematical modeling skill of students in open-ended learning in class VII.6 in SMP Negeri 17 Palembang is categorized good with an average of 78.54%. Students who are still lacking in modeling mathematical problems because they still incorrectly understand the problem and draw up a problem-solving plan.