Indonesia Conference Directory

Corresponding Author
Alberta Parinters Makur

Institutions
1 STKIP Santu Paulus, Jl. Jl. Ahmad Yani no 10, Ruteng, 86511, Indonesia

Abstract
This research was conducted to explore the relationship between formal mathematics and Lingko, a system of traditional agricultural land distribution in Pocoleok, Manggarai-NTT Regency. Lingko was interesting to study concerning mathematics because of the philosophical values contained in lingko and the lingko sharing ceremony. This research focused on two things, namely: (1) how the distribution of ulayat land, Lingko, was mathematically reviewed while still paying attention to cultural values, and (2) how the community practiced mathematical concepts in the distribution of Lingko. The first focus of the problem was to uncover the mathematical activity of the distribution of ulayat land, Lingko, which was unknowingly carried out by the Pocoleok, Manggarai indigenous peoples. Knowledge gained from this first study might produce a new approach to learning mathematics, both from a mathematical or mathematical education perspective. The second focus of the problem seeks to reveal the extent to which the basic concepts of Manggarai culture (following understanding) to solve mathematical problems faced in the reality of life. This second study provides more space for cultural-based mathematics learning, namely how to understand mathematical concepts based on contextual issues that arise in Manggarai culture.

Keywords
Ethnomathematics; Lingko; Mathematics

Topic
Mathematics Education

Link: https://ifory.id/abstract/EBHwy3JVYdNa

Corresponding Author
Erwin Harahap

Institutions
a) Department of Mathematics, Universitas Islam Bandung
Jalan Tamansari No. 1 Bandung 40116, Indonesia.

b) Department of Statistics, Universitas Islam Bandung
Jalan Tamansari No. 1 Bandung 40116, Indonesia.

Abstract
Traffic is a very vital medium for various means of land transportation that connects various locations and even large cities. The smooth traffic of a city is one of the performance parameters of the local government. Furthermore, the smooth traffic determines the great development of economic, social, educational and technology. As the increasing level of civilization development and also the population, traffic becomes more congested and becomes a big problem that is very difficult to avoid. In this study, we proposed a traffic simulator system LINTAS-BD 1.2, or commonly called as "LINTAS" which served as a tool to solve traffic congestion problems. Various methods and traffic engineering designs can be simulated first through the LINTAS system, before they are actually implemented on the road. The benefit of the LINTAS is to evaluate and simulate traffic conditions based on the design of a particular method or traffic engineering. Furthermore, through simulations, it can be known and tested analytically about the level of accuracy, efficiency, and effectiveness of the method and design. Through the simulation, the most appropriate traffic management method can be found, so that the problem of traffic congestion can be solved. The model and the design system of LINTAS is the arrangement and integration of various blocks or modules included: roads, traffic light, arrival of vehicles, queues, servers, and various obstacles such as intersections, terminals, markets, branches, etc. These various blocks are then combined into a single unit application as a simulator. The objective of this research is to compile a simulation application (traffic simulator) that can be used as a tool to accurately predict traffic situations, and as a medium for testing traffic engineering. The LINTAS simulator is created using the SimEvents toolbox and runs on the MATLAB-Simulink software. The LINTAS system is compiled based on Mathematics, specifically the Queueing Theory.

Keywords
traffic, congestion, simulation, queuing networks, simevents-matlab

Topic
Applied Mathematics

Link: https://ifory.id/abstract/DUuP84k26rJ3

Corresponding Author
Indah Puspita Sari

Institutions
IKIP Siliwangi

Abstract
This study aims to design and develop learning trajectories in triangular and quadrilateral material and examine students mathematical understanding by using the local instruction theory. The research method used is design research with 3 stages, namely preliminary design, teaching experiment, and retrospective analysis. The instruments in this study were tests and non-tests. As for the subjects in this study were seventh-grade junior high school students as many as 40 people. This study describes how the learning trajectory developed can affect mathematical comprehension skills. The final result of this study is an increase in students mathematical understanding skills using the local instruction theory

Keywords
Local Instruction Theory, Design Research

Topic
Mathematics Education

Link: https://ifory.id/abstract/Hd8TEVGBhW9D

Corresponding Author
Muhammad Ghiyats Ristiana

Institutions
Department of Mathematics Education, Universitas Pendidikan Indonesia
*kanghiyats[at]upi.edu

Abstract
A teacher should present a lesson concept well, not just only using it to solve a question on exams. However, teacher should make their students understand all of the concepts. This thing should be built since we are in a golden age or in elementary school. Elementary school teacher should have better skills in teaching, because they teach a lesson base, especially mathematics. If students do not understand the base of mathematics, they will not able to solve more complex mathematics problems. Therefore, logical thinking skill is needed for this, especially for an elementary school teacher. The aim of this research is to see whether students of prospective elementary school teacher have a good logical thinking skill or not. In order to do so, we used descriptive qualitative method. We presented an easy mathematics questions to see their logical thinking skills. The result shows that prospective elementary school teacher students did not have good logical thinking skills yet. They still should increase their logical thinking skills to be a better teacher. Their lecturer should have a better teaching concept to make a better elementary school teacher later.

Keywords
Logical Thinking Skills; Primary School Teachers; Mathematics; Prospective Teachers

Topic
Mathematics Education

Link: https://ifory.id/abstract/WYmtv2BQPJdb

Corresponding Author
Bagus Ardi Saputro

Institutions
Universitas PGRI Semarang

Abstract
This research aims to design learning materials with context of onion plantation in Brebes, Central Java, Indonesia. The research began with the observation and interview on how farmer manage and cultivate the plantation area of onions. Finding from this exploration is “gondang”, area of onion plantation made by farmer by which the area larger than that with no gondang. From this finding, designer adopt it to the class. Grid paper is chosen as mathematics tools to model the everyday situation to be mathematics. The preliminary design of the learning materials is learning design on Geometry and Measurement with the applicative domain consider on Princip-s of Realistic Mathematics Education.

Keywords
Ethnomathematics; Learning Design; Realistic Mathematics Education

Topic
Mathematics Education

Link: https://ifory.id/abstract/Mvn462ALDdTU

Corresponding Author
Odorlina Marbun

Institutions
IKIP Siliwangi

Abstract
The purpose of this study is to development research of matematical comunication ability and self regulated learning. The good matematical comunication ability can solve matematicaly problem and self regulated learning maturity will seem in doing matematicaly activity The sucses matematicaly factor were interested students and teacher spirit to development learning ability so that does not cause bore in the class, to construct interest and motivation in learning activities so boredom that are erasier and more enjoyable and matematicaly comunication ability taught self regulated learning when snowball throwing aproach. The experiment to invold 25 grade -7 students in Karawang , Jawa Barat district. The instruments are matematical comunication and self regulated learning abilities test and opinion scale. The study found that: a) Excelent of snowball throwing to improve approach matematical comunication ability students. b) Descripe of matematicaly comunication ability students with low and high very good. c) There was high association betwen matematical comunication ability and self regulated learning. c) Students interested and enjoyable to snowball throwing approach.

Keywords
snowball throwing,matematical comunication

Topic
Mathematics Education

Link: https://ifory.id/abstract/RM6ga23vrCVA

Corresponding Author
Rosliana Siregar

Institutions
Universitas Islam Sumatera Utara

Abstract
In learning mathematics mathematical connections ability is one of the mathematical ability that must be possessed by students. The strong connection between concepts in mathematics implies that mathematical connections ability also contains other mathematical aspects or vice versa. Viewing mathematics as a whole is very important in learning and thinking about connections between topics in mathematics. This study uses qualitative research methods with phenomenology research design types. The participants in this study were 8 middle school mathematics teachers who taught at different schools. This study uses a short interview form which consists of five open questions to determine the teachers understanding of mathematical connection ability. It was found that middle school math teachers had sufficient comprehensive and adequate knowledge of their views on mathematical connection ability, moreover there were also respondents who could not provide examples of mathematical problems that contained the characteristics of mathematical connection ability even though they were able to define what mathematical connection is. Likewise, the development of teachers in mathematical connection ability in learning is still limited to the scope of the relationship of mathematics with mathematics itself and mathematics with everyday life.

Keywords
mathematical connection ability, perception, phenomenology.

Topic
Mathematics Education

Link: https://ifory.id/abstract/9CFPVEngKDJb

Corresponding Author
Anik Yuliani

Institutions
IKIP Siliwangi

Abstract
The purpose of this study is to analyze students creative problem solving (CPSM) abilities based on the cognitive stage. The number of students involved in this study was 32 eighth grade students, a set of TOLT to determine the cognitive stage of students and a description test (CPSM). The results of this study found that: a. as many as 70% of students are still at the concrete stage, 25% of students are in the transition stage, and 5% have reached the formal stage; b. Overall students achieve CPSM quality at a moderate level; but there are differences in CPSM quality between students in the formal, transition and concrete stages; The CPSM quality of the students is in the formal stage, the transition phase, and the concrete stages are successively at a fairly good level, medium, and lacking; c. Concrete stage students experience more difficulties in completing CPSM tasks, while students in the transitional and formal stages only experience little difficulty in completing CPSM tasks.

Keywords
cognitive development stage, TOLT, mathematical creative problem solving

Topic
Mathematics Education

Link: https://ifory.id/abstract/atGgHkwQByeW

Corresponding Author
Rippi Maya

Institutions
1) Pendidikan Matematika, IKIP Siliwangi, Cimahi, Indonesia
2) Pendidikan Matematika, Universitas Islam Negeri Sunan Gunung Djati, Bandung, Indonesia
3) Pendidikan Guru Madrasah Ibtidaiyah, Universitas Islam Nusantara, Bandung, Indonesia

Abstract
The purpose of this study is to analyze the ability of mathematical critical thinking of Mathematics Education students. The subjects are 86 students of one university in Bandung, who took Ordinary Differential Equation Course. The length of the study is about 4 months. In the first two months, the students got the Direct Learning and the other two months, the students got the Indirect Learning. Instruments in this study were two sets of critical thinking test, which consist of each three essay questions. The results showed that the mathematical critical thinking ability of students is low. There are no difference abilities of mathematical critical thinking among the two learning approach, their achievements are still in low categories. Among the three indicators of the tests, ‘identifying the underlying concepts- got the lowest score, ‘answering question with relevant reasons- got the medium score and ‘examining the truth of the statements and explain it- got the highest score, but those three scores are still in low category.

Keywords
mathematical critical thinking, ordinary differential equation, direct learning, indirect learning

Topic
Mathematics Education

Link: https://ifory.id/abstract/WT47Pa9EBpdF

Corresponding Author
Harry Dwi Putra

Institutions
a) Mathematics Education, Institut Keguruan dan Ilmu Pendidikan Matematika Siliwangi
Jalan Terusan Jenderal Sudirman, Cimahi 40526, Indonesia

Abstract
Prospective mathematics teachers must have critical thinking skills and confidence in teaching. To study the critical thinking skills and self-confidence of prospective mathematics teacher students, research needs to be done. The research subjects were 32 students of mathematics teacher candidates at one of the universities in Cimahi. The instruments used included tests of mathematical reflective thinking skills and a self-confidence scale that had been validated by three experts in the field of mathematics education. Prospective teacher students are grouped according to high, medium and low levels. The results of data analysis showed that mathematical critical thinking skills of students of mathematics teacher candidates at 9.38% had high criteria, 12.50% had moderate criteria, and 78.13% had low criteria. The self-confidence of mathematics teacher prospective students is 90.63% having high criteria, 6.25% having moderate criteria, and 3.13% having low criteria. This finding states that prospective mathematics teacher students have a low level to mathematical critical skills but have high self-confidence.

Keywords
Mathematical Critical Thinking Skills; Self-Confidence; Prospective Teacher Students

Topic
Mathematics Education

Link: https://ifory.id/abstract/BCgtMyDkKWn2

Corresponding Author
Martin Bernard

Institutions
a) Fakultas Pendidikan Matematika dan Sains, Institut Keguruan dan Ilmu Pendidikan Siliwangi, Jalan Terusan Jenderal Sudirman, Cimahi 40526, Indonesia
*pamartin23rnard[at]gmail.com
b)Fakultas Ilmu Pendidikan, Institut Keguruan dan Ilmu Pendidikan Siliwangi, Jalan Terusan Jenderal Sudirman, Cimahi 40526, Indonesia

Abstract
Mathematical deterministic algorithms are a method for solving mathematical problems that are appropriate in every step of an algorithm. Where each student will make steps from the questions given, then they make the right decisions to link the relationship of mathematical language into the language of the ActionScript 3.0 program through several processes so that the goal of media creation is achieved as a result of the implementation of the algorithm. The purpose of the method is to provide student knowledge of the meaningfulness of mathematics learned can be implemented in everyday life. Students can make their own decisions to make the right strategy in solving problems, Students learn to develop their own different processes to the right results. ActionScript 3.0 is a programming language based on ECMAScript which is a standard language program developed by ECMA (European Computer Manufacturer Association) that provides a student or prospective teacher to make a product in the form of more interactive images or animations as innovative learning media and learning enrichment applications Internet. Of course the development is based on students creative abilities to achieve the objectives of various processes in the form of algorithms made, after which results are tested, checking and observing steps that need to be corrected if an error occurs or added if there is a need to develop, finally students give the right conclusions from the process beginning to end process.

Keywords
Mathematical Deterministic Algorithm, ActionScript 3.0 Adobe Flash, Student Creative Reasoning Capabilities

Topic
Mathematics Education

Link: https://ifory.id/abstract/2RND8pbxhjKL

Corresponding Author
Eva Dwi Minarti

Institutions
IKIP Siliwangi

Abstract
This study aims to examine the effect of mathematical disposition of junior high school students on mathematical critical thinking skills. A quantitative approach with a correlational method used by researchers to examine both variables. The subjects in this study were 32 students of class VIII in one of the Bandung junior high schools. The instrument used consists of a test instrument which is a test of mathematical critical thinking skills with indicators that are interpretation, analysis, evaluation and conclusion. The results of the study show that the mathematical disposition of junior high school students has a positive influence on mathematical critical thinking skills. Students with a positive disposition toward mathematical learning can interpret and not hesitate to express ideas.

Keywords
Mathematical Disposition, Mathematical Critical Ability, Middle School Students

Topic
Mathematics Education

Link: https://ifory.id/abstract/tX8HPMQbGm9h

Corresponding Author
Mega Nur Prabawati

Institutions
1. Pendidikan Matematika, Universitas Siliwangi, Jl. Siliwangi No. 24 Kota Tasikmalaya, Jawa Barat Indonesia

2. Universitas Pendidikan Indonesia, Jl. Dr. Setiabudhi No. 229 Bandung 40154 Jawa Barat Indonesia

Abstract
Having good mathematical literacy skills is expected to help students solve problems related to mathematics. The focus of mathematics literacy skills on students is the ability to analyze, justify, and communicate ideas effectively, formulate, solve and interpret mathematical problems in various forms and situations. This study aims to describe students mathematical literacy skills seen from gender differences. The approach used in this study is a qualitative approach with case studies. The study subjects consisted of two male students and two female students from junior high school students. Data was collected through analysis of student work results and interviews.. Students are asked to convey what they are thinking when solving problems in a given mathematical literacy test. After students finish getting the solution from the problem, the researcher classifies the students answers and analyzes them. Furthermore, the data obtained are grouped and analyzed according to indicators of mathematical literacy skills. Male students have good results from each indicator in mathematical literacy ability, namely in the first indicator of the sixth indicator, while for female students have good mathematical literacy skills for the first indicator, second indicator, third indicator, fourth indicator and sixth indicator, except for the fifth indicator, female students have sufficient mathematical literacy skills.

Keywords
Literacyt, Mathematicall literacy skill, gender.

Topic
Mathematics Education

Link: https://ifory.id/abstract/9fgXDpWCerJb

Corresponding Author
Indrie Noor Aini

Institutions
(a) Universitas Singaperbangsa Karawang, (b) Universitas Sriwijaya Palembang, (c) Universitas Pasundan Bandung

Abstract
The aim of this study is to develop valid and practical mathematical problems of PISA-like with “Tugu Kebulatan Tekad” contexts in Karawang. The subjects were tenth-grade students of senior high school, research methodology used was designed research with the type of development study divided into 2 stages, preliminary and formative evaluation. The preliminary stage included the student analysis, curriculum analysis, and analysis of PISA problems. Formative evaluation stage included one-to-one and expert reviews than the small group. Data collection techniques used were documentation, walk through, interview, and observation. The aim of this study is to develop valid and practical mathematical problems of PISA-like with “Tugu Kebulatan Tekad” contexts in Karawang. Valid based on the results of the validator assessment at the expert reviews phase which states that the matter had been well viewed in terms of content, constructs and language and workmanship of students at the one-to-one phase. Practical could be seen from small group phase that students could use the problem device well.

Keywords
mathematical problems, PISA-like, Tugu Kebulatan Tekad

Topic
Mathematics Education

Link: https://ifory.id/abstract/9ZaHcj4fDpvV

Corresponding Author
Ambar Prawoto

Institutions
Mathematics Education Program Post Graduate IKIP Siliwangi, Cimahi

Abstract
This study was a descriptive survey having a goal to examine attainment of student-s mathematical reasoning (MR) and self regulated learning(SRL) according to student-s cognitive stage. The survey implicate 36 eleventh grade students of 17 years old, test of logical thinking (TOLT), an essay MR test,a SRL scale. By using TOLT, the survey investigated many students with 17 years old had not reached formal cognitive stage, namely 19 % students at formal stage, 25 % students at transition stage, and rest 56% students at concrete stage. In addition, survey invented that entirely students obtained MR at very low grade level, and according to student-s cognitive stage, formal students obtained higher grade MR than the grade of transisiton students and concrete students. Even if, those grades were still at low and very low level. Either entirely or based on student-s cognitive stage there were no different grades on student-s SRL and those grade were fairly good level. SRL at fairly good grade level, transistion stage students attained MR and SRL at medium grade Other finding, there was medium association between cognitive stage and MR, but therewere no association between cognitive stage and MR, and SRL and between MR and SRL. In general, these findings were, that in normal condition formal cgnitive stage will reach by students in 12 -13 years old, or in 13-14 years old, even in specific condition in 19 – 20 years old; and that formal students possess higher abilities than concrete students on completing HOT tasks such as MR tasks which needed formal operational thinking.

Keywords
cognitive stage, TOLT, mathematical reasoning, self regulated learning.

Topic
Mathematics Education

Link: https://ifory.id/abstract/McFDj6JpBxXq

Corresponding Author
Gunawan, S.Pd.I

Institutions
Mathematics Education Program Post Graduate IKIP Siliwangi, Cimahi

Abstract
This study was a descriptive survey having a goal to examine attainment of student-s mathematical reasoning (MR) and self regulated learning(SRL) according to student-s cognitive stage. The survey implicate 36 eleventh grade students of 17 years old, test of logical thinking (TOLT), an essay MR test,a SRL scale. By using TOLT, the survey investigated many students with 17 years old had not reached formal cognitive stage, namely 19 % students at formal stage, 25 % students at transition stage, and rest 56% students at concrete stage. In addition, survey invented that entirely students obtained MR at very low grade level, and according to student-s cognitive stage, formal students obtained higher grade MR than the grade of transisiton students and concrete students. Even if, those grades were still at low and very low level. Either entirely or based on student-s cognitive stage there were no different grades on student-s SRL and those grade were fairly good level. SRL at fairly good grade level, transistion stage students attained MR and SRL at medium grade Other finding, there was medium association between cognitive stage and MR, but therewere no association between cognitive stage and MR, and SRL and between MR and SRL. In general, these findings were, that in normal condition formal cgnitive stage will reach by students in 12 -13 years old, or in 13-14 years old, even in specific condition in 19 – 20 years old; and that formal students possess higher abilities than concrete students on completing HOT tasks such as MR tasks which needed formal operational thinking.

Keywords
cognitive stage, TOLT, mathematical reasoning, self regulated learning.

Topic
Mathematics Education

Link: https://ifory.id/abstract/FX3dmhkUNKZL

Corresponding Author
Adi Nurjaman

Institutions
IKIP Siliwangi

Abstract
This study aims to examine conducting in-depth studies of mathematical reasoning abilities based on gender and learning motivation. The research design used in this study is a case study and grounded theory. The researcher chose to use the case study design because the researcher wanted to explore in depth and in detail the subjects to be studied using various procedures to collect data and answer the researchers questions. Researchers use qualitative research because researchers want to explore deeply about the things that affect the occurrence of something. The procedure for the grounded theory design process is open coding, axial coding, and selective coding. The school which is the place of research is one of the junior high schools in West Bandung Regency. Determination of subjects purposively based on characteristics that bloom in each student. The results in this study are high-ability students who tend to be able to estimate answers and process solutions in solving problems, for students with moderate abilities tend to be able to use patterns and relationships to analyze

Keywords
mathematical reasoning abilities; gender

Topic
Mathematics Education

Link: https://ifory.id/abstract/RK8YXNBEJkmp

Corresponding Author
Luvy Sylviana Zanthy

Institutions
a) IKIP Siliwangi
Jalan Ters. Jend.Sudirman, Cimahi, Indonesia
*zanthyluvy[at]gmail.com

b) Universitas Pendidikan Indonesia
Jalan dr. Setia Budhi, Bandung, Indonesia

Abstract
The aim of this study is to analyze the mathematical resilience of high school students. The instrument used The Norm Reference Value (NRV), which consisted of 42 items. This Resilience Test consist of 6 indicators, that is: 1) Diligent, confident, working hard and not easily giving up on problems, failures and uncertainties; 2) Desire to socialize, easily provide assistance, discuss with peers, and adapt to their environment; 3) Bring up new ideas/ ways and find creative solutions to challenges; 4) Using experience of failure to build self motivation and self control; 5) Showing curiosity, reflecting, researching, utilizing various sources; 6) Having language skills, controlling themselves and being aware of their feelings. The resilience analysis based on a comparison of the average value of each indicator with a reference value that has been determined in NRV. The results showed that all indicators were in medium category.

Keywords
Mathematical Resilience

Topic
Mathematics Education

Link: https://ifory.id/abstract/cFrTbtfKxPNE

Corresponding Author
Amelia Utari

Institutions
Sriwijaya University

Abstract
Indonesia has experienced the improvement of PISA result despite the result is lower than other countries. therefore, the result of this study is to find out the studentss mathematics literacy ability in using PISA model questions in the context of coconut. this article also describe the studentss ability in solving mathematical problem in the context of coconut. this is a design research with two development studies types, namely preliminary and formative evaluation which include self evaluation, expert reviews, one to one, small group and field test. based on the result of analysis, the researcher showed that in solving the mathematical problem of PISA model in the context of coconut tree, students mostly utilize to choose strategy in solving the problem and communication ability.

Keywords
Design Research, Mathematical literacy, PISA, PMRI

Topic
Mathematics Education

Link: https://ifory.id/abstract/BmDeUVZH7XtM

Corresponding Author
Yanti Mulyanti

Institutions
1Program Studi Pendidikan Matematika, FKIP UMMI
2Pendidikan Matematika, FMIPA UPI
3Pendidikan Matematika, FMIPA UPI
4Pendidikan Matematika, FMIPA UPI

Abstract
This study aims to determine the initial ability of students of the Mathematics and Teaching Faculty of Muhammadiyah Sukabumi (FKIP UMMI) Mathematics Education Study Program as a mathematician (Mathpreneur) entrepreneur who has contracted Entrepreneurship courses. The research method used is descriptive with a quantitative approach. Data collection using survey methods, using instruments in the form of questionnaires whose statements are based on the components of entrepreneur character.

Keywords
The character of Mathpreneur, Student of Mathematics Education

Topic
Mathematics Education

Link: https://ifory.id/abstract/cDBVjJAZ3286

Corresponding Author
Benidiktus Tanujaya

Institutions
University of Papua

Abstract
The purpose of this research was to study the application of think pair share, the type of cooperative models, which can be implemented in mathematics instruction in Manokwari, West Papua Indonesia. This study was conducted at Senior High School of Manokwari (SMA Negeri 1) and Mathematics Education Department, the University of Papua. The research was carried out using research and development methods. The results showed that there were two main things in the application of the think pair share model in mathematics instruction in Manokwari West Papua, particularly the selection of group members and the determination of the number of group members. Group members must consist of students who already know each other well, while the number of group members must start from two students.

Keywords
modification of think pair share, mathematics instruction

Topic
Mathematics Education

Link: https://ifory.id/abstract/Dnc3wZpWTX9e

Corresponding Author
Findinilah Faraswati

Institutions
1)Departemen Pendidikan Matematika, Sekolah Pascasarjana, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi No. 229, Bandung 40154, Indonesia
*findinilah.faraswati[at]upi.edu
2)Departemen Pendidikan Matematika, Universitas Pendidikan Indonesia, Jl. Dr. Setiabudi No. 229, Bandung 40154, Indonesia

Abstract
The underlying problem of this research is the lack of students competencies in understanding the concept area of triangle in geometry as the results of the teaching and learning pattern that only receiving information rather than to construct knowledge. The process of construct knowledge by students during learning requires high attention and motivation from students for learning which is then facilitated by the teacher. The purpose of this research is to develop the didactical design of area of triangle that is to construct knowledge and motivation to learn geometry involving student motor action. The used research method is a qualitative research in the form of the didactical design research through three phases of analysis i.e. didactical situation analysis, metapedadidactical analysis, and retrospective analysis, which conducted in students from 7th grade at one of public schools in West Bandung Regency. Based on the results of research and analysis, the didactical designs that has been made is capable to change students learning habit, construct students learning motivation and are quite capable of developing students competencies in the concept of triangle area.

Keywords
motoric action; didactical design; learning of triangle area

Topic
Mathematics Education

Link: https://ifory.id/abstract/qWXzrVme2uBp

Corresponding Author
Christine Wulandari Suryaningrum

Institutions
a) Universitas Muhammadiyah Jember

Abstract
Representation has an important role in solving mathematical problems. Problems that initially seem difficult and complicated can be seen more easily and simply by considering its representations. Mathematical expressions can be interpreted with various representations including visual representation, symbol representation, verbal representation and multiple representations. In Peirce theory, semiotic consists of three aspects, namely sign, object and interpretant. A semiotic reasoning is a process of deducing a conclusion based on the object, sign (representamen), and students interpretation in interpreting the meaning of sign (interpretant). This study aims to identify the mathematical representations of 3rd grade students in solving problems of fractions. The type of this study is qualitative research with case analysis of case studies. The participants of the present study are 3rd grade students of a private primary school in Jember. The results show that first participant 1 used verbal, visual, and symbol representations. The steps taken by the first participant in solving the problems were correct but the participant drew a wrong conclusion caused by the lack of practice in solving non-routine problems. Second participant solved the problem by using verbal and visual representations. The second participant described the solution with verbal ability and could solve the problem correctly. Third participant solved the problem by employing verbal and visual representations. The steps of the third participant in solving problem were correct but the participant drew a wrong conclusion caused by the lack of ability in understanding the concept of fractions. The conclusion is three participants used multiple representations, namely visual, verbal, and symbol representation in solving a problem.

Keywords
visual representation; verbal presentation; symbol representation; problem solving; fraction

Topic
Mathematics Education

Link: https://ifory.id/abstract/DgtU4NHVmTJG

Corresponding Author
Luthfi Hakim

Institutions
Universitas Islam Majapahit

Abstract
New results in the form of velocity distribution in the square duct elbow 90-degree have been obtained from the simulation results. The flow characteristics through which are analyzed using commercial CFD software. The Reynolds averaged Navier Stokes (RANS) equation will be solved numerically using the finite difference method and using the SIMPLE algorithm. The test model to be used in this study is square duct which is installed in the inlet section 90-degre elbow with a double damper placed at a distance offrac{x}{D_{h}}=2 after out late elbow. In this paper, the effect of the damper opening angle on the velocity profile on the 90-degree square duct is simulated in simulation at the opening angle of 30-degree clockwise direction and 30-degree counter-clockwise direction. The simulation results in the form of velocity profile distribution in each position are shown through the graph and obtained a maximum velocity magnitude value of 26.143 m/s which is exactly the place of the damper.

Keywords
Double damper, velocity profile, square duct

Topic
Applied Mathematics

Link: https://ifory.id/abstract/GAcNZzbLx2ad

Corresponding Author
MOH IVAN AZIS

Institutions
Hasanuddin University

Abstract
A boundary element method is utilized to find numerical solutions to boundary value problems of trigonometrically graded media governed by a spatially varying coefficients anisotropic-diffusion convection equation. The variable coefficients equation is firstly transformed into a constant coefficients equation for which a boundary integral equation can be formulated. A boundary element method (BEM) is then derived from the boundary integral equation. Some problems are considered. The numerical solutions justify the validity of the analysis used to derive the boundary element method with accurate and consistent solutions. A FORTRAN script is developed for the computation of the solutions. The computation shows that the BEM procedure elapses very efficient time in producing the solutions. In addition, results obtained from the considered examples show the effect of the anisotropy of the media on the solutions. An example of a layered material is presented as an illustration of the application.

Keywords
Boundary element method; Steady anisotropic-diffusion convection equation; Trigonometrically graded media; Incompressible flow

Topic
Applied Mathematics

Link: https://ifory.id/abstract/PZRAu4w3xpah

Corresponding Author
Faryad Ali

Institutions
Al-Imam Mohammad Ibn Saud Islamic University (IMSIU),
Riyadh 11623,
Kingdom of Saudi Arabia

Abstract
The projective special orthogonal group $PSO^+_8( 3) cong O^+_8(3).2_1$ is a group obtained from the special orthogonal group $SO_8(3)$ on factoring by the group of scalar matrices it contains. The group $PSO^+_8( 3)$ has a maximal subgroup of the form $2^6{cdot}S_8$ with index $3838185$. The group $ar{Q}cong 2^6{cdot}S_8$ is a non-split group extension of an elemenrary abelian $2$-group of order $64$ by the symmetric group $S_8$. In the present article, we construct the non-split extension $ar{Q}$ and compute its character table by using the Fischer-Clifford matrices.

Keywords
Fischer matrices; Non-split extension; Character table

Topic
Applied Mathematics

Link: https://ifory.id/abstract/u4ZyLqYG7bDr

Corresponding Author
NURDINI ELMUNAWARAH

Institutions
a) Master of Mathematics Education, Sriwijaya University, Komplek Unsri Jalan Srijaya Negara Bukit Lama, Kec. Ilir Barat I, Palembang 30137, Indonesia
*ratu.ilma[at]yahoo.com
b) Master of Mathematics Education, Sriwijaya University, Komplek Unsri Jalan Srijaya Negara Bukit Lama, Kec. Ilir Barat I, Palembang 30137, Indonesia

Abstract
The aims of this article was to design PISA-like problems of mathematics by using online ticketing system as its context and Macromedia Flash as its media that is valid, practical, and has potential effects. This research method is Design Research type of development studies with two stages, namely preliminary and formative evaluation. The research subjects were class X students of Senior High School Number 1 Palembang. Data collection techniques with documents, wolkthrough, tests, interviews, and observations. In the learning process, this research uses the Indonesian Realistic Mathematics Education (PMRI) approach with the Lesson Study for learning Community (LSLC) system where all mathematics teachers in class X are involved starting from the process of developing the problem to the field test. Based on the results of the study it was found that the mathematical problem of the PISA model uses the context of online tickets through interactive learning media assisted by Adobe Flash Macromedia which is valid and practical, and has potential effects. Valid in terms of content, constructs, language, and workmanship of students in the one-to-one stage. Practical seen from the workmanship of students in the small group stage. From the results of the field test it was found that the problem has a potential effect on mathematical literacy skills, namely communication, mathematizing, representation, reasoning and argument, devising strategies for solving problems, using symbolic, formal, and technical language and operation.

Keywords
PISA, Mathematical Literacy, Online Tickets, Macromedia Adobe Flash

Topic
Mathematics Education

Link: https://ifory.id/abstract/pvBtJnjR9GaL

Corresponding Author
Rika Amelia

Institutions
a) Master Program in Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, INDONESIA
*rika17003[at]mail.unpad.ac.id
b) Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, INDONESIA

Abstract
One of the main obstacles in crop cultivation is the occurrence of fungal infections. Fungal spores can spread due to direct contact between susceptible hosts and infected hosts, which can be controlled using botanical fungicides. We constructed a mathematical model of the growth of logistics on the spread of plant diseases. From this model, we show the value of the Basic Reproduction Number (R0) of plant diseases transmission. The value of R0 is obtained by finding the largest eigenvalue of the next generation matrix. The results obtained show that when R0 is greater than one (R0>1), the endemic equilibrium point will be stable. However, if R0 is less than one (R0<1), the endemic equilibrium point is unstable. In addition, the results of this discussion indicate that by using botanical fungicides can reduce the infected host population. We provide numerical simulations to describe the results of the analysis obtained.

Keywords
Basic Reproduction Number; Local Stability Analysis; Optimal Control

Topic
Applied Mathematics

Link: https://ifory.id/abstract/RJNaQbHnjVmv

Corresponding Author
Tri Susilawati

Institutions
a) Department of Civil Engineering, Sumbawa University of Technology
jalan Raya Olat Maras Kecamatan Moyo Hulu Kabupaten Sumbawa 84314, Indonesia
*tri.susilawati[at]uts.ac.id
b) Department of Agro Industrial Technology, Sumbawa University of Technologi
*mikhratunnisa[at]uts.ac.id

Abstract
The utilization of land in Sumbawa District to produce corn will effect cutting trees new land fields It-s not paddi field . It has effect on environment. Those such as lack of water in ground, flood, and soon. Henceforth this research aim at making optimation model cutting tree for new land could enhance the productivity of corn and making appropriate model to optimalize of farmets benefit by using simplex methode. Based on simplex counting, it-s needed 21.618 and 77.873 Ha paddy field and non paddy field to plant corn in order to increase corn harvest. To boost farner-s benefit, they harvest 672609 tonas follows, 434.001 ton of corn by 15% of water content, 46.182 ton of corn by 20% of water content and 192.426 ton of corn by 25% of water content.

Keywords
Simplex Method, Optimization, Corn

Topic
Applied Mathematics

Link: https://ifory.id/abstract/8BJmEew9WTkA

Corresponding Author
Kalfin Kalfin

Institutions
a) Master Program in Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Jatinangor 45363, Sumedang. West Java, INDONESIA
*kalfin17001[at]mail.unpad.ac.id
b) Department of Mathematics, Faculty of Mathematics and Natural Sciences, Universitas Padjadjaran, Jl. Raya Bandung-Sumedang Km 21, Jatinangor 45363, Sumedang. West Java, INDONESIA

Abstract
Investing in mining stocks, investors are often faced with risk problems. Usually to minimize risk, this is done by forming an investment portfolio. This paper aims to discuss the optimization of the investment portfolio. The data analyzed are several mining stocks traded on the capital market in Indonesia. Optimization is done by using the mean-absolute deviation model to determine the optimal weight. Where optimization is done using a singular covariance matrix. Based on the results of optimization, we can obtain a weight allocation composition that provides an optimal portfolio. In addition, we also predict the amount of return on expectations and risks in the optimal portfolio formed. So that the composition of this optimal weight can be used as a consideration for investors in investing their capital in several analyzed mining stocks.

Keywords
Mining stocks, return, portfolio, optimization, mean-absolute deviation

Topic
Applied Mathematics

Link: https://ifory.id/abstract/r3WuLFpqfdcb