bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stability and Numerical Simulation of Prey-predator System with Holling Type-II Functional Responses for Adult Prey
Authors: Savitri Dian 
Published: December 2019

Abstract
In this paper, we analyze the local stability of the prey-predator model. This model was constructed from two prey involving stage-structure and one predator. The population of prey is divided into two subpopulations, adult prey and immature. The ratio of intrinsic growth of predator population density divided by adult prey conversion factors into a predator. Reduction of predator populations has a reciprocal relationship with the availability of favorite foods determined by the environmental resources. We also consider that Holling type II the functional response for the predator. We have investigated the local stability and the solution of the system. We have studied the existence and feasibility of various equilibrium points. The system has three positive equilibria, namely the original, the extinction of the predator and the interior point. We explore the stabilities of all nonnegative equilibrium point by the real parts of the eigenvalues of the Jacobian matrix at each equilibrium point must be negative. We also use the Routh-Hurwitz criterion to investigate the stability at the interior equilibrium point. This study aims to detect the limit cycle with its phase portrait and its time-series graphs of the prey-predator system. Numerical simulated are represented as phase portraits to draw the stability of the equilibrium point. In our Numerical outcomes confirmed the analytical results and the local behavior prey-predator model which start from their positive initial condition. The parameter value is taken mainly from the literature and assumption. By a computational Python using the fourth-order Runge-Kutta method, we solved the prey-predator system and showed some new phase portraits such as the existence of the stable or unstable equilibrium point under a suitable value of the parameter. The next research, we will explore the global stability analysis behavior of the interior equilibrium point.
Estimation of Super Pairwise Alignment (SPA) parameters on zika virus mutation using Artificial Bee Colony
Authors: Rahmalia D , Rohmatullah A , Pradana M S 
Published: December 2019

Abstract
There are many diseases caused by viruses or bacteria. The structure of virus and bacteria always mutate to create new structures. Sequence alignment is important so that it can be used to research genetic diseases and epidemics. In this reseach, we take case study of zika virus. To see the similarity between original virus and the mutation virus, it is required the alignment process of two virus sequences. The method used for aligning two virus sequences is Super Pairwise Alignment (SPA). Due to the value of objective function depends on SPA parameters, in this research we will apply heuristic method, such as Artificial Bee Colony (ABC) algorithm to optimize SPA parameters minimizing penalty value or maximizing similarity value as objective function. ABC is the optimization method which is inspired by the behaviour of bee colony in which the advantages are there are three types of bees that will update optimal solution in approaching. From the ABC simulations, we can obtain optimal SPA parameters resulting minimum penalty value or maximum similarity value between two aligned zika virus protein sequences in approaching.
Magnetic property approach for identification of dominant crystal structure in AISI420 treated by RF-DC Plasma N2-H2
Authors: Herdianto H 
Published: December 2019

Abstract
The nitridation of RF-DC plasma N2-H2 into AISI420 produces several phases namely α’ (bcc),ε (hcp), and γ (fcc) which are randomly distributed in a number that is difficult to identify. So the most dominant justification of crystal phase was needed. Based on the concept of isothermal transformation of AISI420 transformed from the α’ phase (ferromagnetic), to ε phase (paramagnetic), and to γ phase (nonmagnetic). It can be used as the underlying theory that magnetic property approach can potentially identify the dominant crystal phase. This study measured the magnetic properties of AISI420 treated by RF-DC plasma N2-N2 for identification of dominant crystal structure. Based on the hysteresis curve (M-H loop) of VSM method, magnetic characteristics can be produced such as susceptibility. Furthermore, the atomistic simulations were performed with the LAMMPS. Modelling of schematic picture of the structure using VESTA v.3.3.2 64 bit. Susceptibility value of AISI420 treated with RF-DC Plasma N2-H2 is range in the notation of 10-5 to 10-3, so it meets criteria of 10-5 ⩽ 10-3 which can be categorized as paramagnetic and super-paramagnetic. It has the dominant ε-Fe3N phase with trigonal-hcp microstructure based on magnetic property approach and simulations of LAMMPS and VESTA.
The Potency and Food Safety of Lamp Shells (Brachiopoda: Lingula sp.) as Food Resources
Authors: Ambarwati R , Rahayu D A , Faizah U 
Published: December 2019

Abstract
Lamp shells is one of primitive brachiopods that can be found in the tropical region. One species of brachiopod has been reported found in Indonesia. This invertebrate is collected by local people for consumption as well as traded in the local market in the area of the southern shore of Madura Island and the northern shore of East Java, Indonesia. This research aimed to analyze the potency of lamp shells as food resources based on the protein and fat content and to evaluate the food safety based on the content of lead (plumbum) and cadmium. The sample of lamp shells was collected from Probolinggo beach. Fresh samples of flesh and pedicle of lamp shell were kept in a cool box for laboratory analysis. The protein content was analyzed using Kjeldahl method, while the content of fat was analyzed using soxhlet method. In addition, the level of plumbum and cadmium in the flesh and pedicle of lamp shell were tested using atomic adsorption spectroscopy. The results revealed that both of the flesh and the pedicle of lamp shells contained protein, namely 14.02±0.62% and 12.06±0.44% respectively. The flesh contained 1.12±0.13% of fat, meanwhile, the pedicle contained 0.84±0.07% of fat. These nutrient content were comparable other marine invertebrates. It seems that the nutrient content outweighs the content of heavy metal that can be accumulated in the sessile invertebrate. The content of plumbum in the flesh and pedicle of lamp shells were 0.10±0.01 ppm and 0.08±0.01 ppm respectively. Meanwhile, the content of cadmium in the flesh and pedicle of lamp shells were 0.09±0.01 ppm and 0.06±0.01 ppm respectively. These numbers are considerably lower that the level permitted. Hence, it can be concluded that lamp shells has potency as food recources.
The Content Validity of Digital Test Items for Evaluation Courses Based on Superitem-Wondershare Using Aiken’s Calculation
Authors: Divayana D G H , Adiarta A , Sudirtha I G 
Published: December 2019

Abstract
The digital test item for evaluation courses that is designed with tiered arrangements use super item concept and is showed digitally use the Wondershare application makes it easy for students to practice the quality of their critical thinking in working on test questions whenever and wherever they are. But to get the good quality test items, then it is still necessary to test the item validity properly and accurately. The method that can be done to determine the valid test items is through calculating the validity of the items uses the Aiken model. Based on those matters, the purpose of this study was to show the calculation process of the test items validity uses the Aiken model. Subjects that were involved in the calculated process the validation of each test item were four experts, including two experts in the field of evaluation and two experts in the field of informatics engineering. The tool was used to assess the test items was a questionnaire consisting of 42 question items. The method used to analyze the test items was by comparing the results of the test item validation used the Aiken model with the validation classification according to Guilford. The study results were showed that from 42 test items tested; there were two invalid items and 40 valid items.
Statistical reasoning or statistical method: Students’ preferences for learning Statistics
Authors: Kusumarasdyati  
Published: December 2019

AbstractStatistical reasoning should precede the statistical method in the teaching of statistics because the students should master the concepts before they perform computations. To find out whether the students were aware of this principle, the present study explored their preference and the underlying reasons. Twenty undergraduates were taught central tendency and variability by using statistical method (with machine computation) and statistical reasoning (with manual computation) respectively in one session. Most of them turned out to prefer to reason and compute numeric data manually because they understood the statistical concepts and the process of the computation. On the other hand, the rest of the undergraduates preferred the teaching of statistics using the statistical method with machine computation for three reasons: accuracy, efficiency, and convenience. The implications of these findings for the teaching of statistics were presented.
Ancient China history-based task to support students’ geometrical reasoning and mathematical literacy in learning Pythagoras
Authors: Fachrudin A D , Ekawati R , Kohar A W , Widadah S , Kusumawati I B , Setianingsih R 
Published: December 2019

Abstract
This study aims to identify the potential learning opportunities provided by ancient china’s geometric diagram introduced by Liu Hui into student task in learning Pythagorean theorem. We investigate the role of the history-based task, from Nine Chapter, in supporting students’ mathematics literacy and geometrical reasoning. Design research was chosen as a method to reach the purpose. Our discussion is limited only from a part of one phase, namely pilot experiment, from three main phases of design research. This research was conducted at three different Junior High schools in Indonesia. The instructional activities were designed based on history-based problem-solving. The analysis was focused on students’ learning process, and specifically, the results of their visual reasoning and mathematical literacy. The result indicated that the use of figures or diagrams, with written information act as a support for performing algebraic calculations for students who are unfamiliar using symbol or algebraic operation. In this way, by using geometric manipulation, a new figure is arrived at on which the solution can now be read easier. Furthermore, by using history-based context, students got more opportunities to improve their performance in mathematics literacy by formulating various contextual mathematics problem, sourced from history, into mathematical form.
Student’s Mathematical Representation in Solving Geometry Problems Based on Cognitive Style
Authors: Adnan S , Juniati Dwi , Sulaiman Raden 
Published: December 2019

AbstractThis research aims to describe the student’s mathematical representation of junior high school who had field independent cognitive style and field dependent in solving geometry problem. Subjects were selected based on the test results of the Group Embedded Figures Test (GEFT), and had equivalent mathematical abilities. The research subjects consisted of two female students who had field independent and field dependent cognitive style. This research uses a qualitative method. The results showed that the subject used mathematical representation in expressing his idea to solve geometry problems by using Polya’s problem solving. The mathematical representation of field independent in solving geometry problem is: understanding information and what is asked in verbal, devising a plan in a visual of geometric images, then presenting verbal plans, carrying out the plan in symbolic by doing calculations, and looking back in symbolic by doing recalculation. Where as field dependent mathematical representations to solving geometry problems is: understanding information and asking in visual of geometrical images and verbal, devising a plan in a visual in the form of subsequent images presenting verbal plans, carrying out the plan in symbolic by performing calculations, and looking back in symbolic in the form of recalculation.
Student’s Multiple Representation in Solving Addition and Subtraction of Fraction Problem
Authors: Yuliani T W , Fuad Y , Ekawati R 
Published: December 2019

Abstract
Fraction is one of mathematics’ topics that difficult to be understood. Many representation form from fraction. Representation has an important role in mathematic. Representation helps student to create mathematic ideas more concrete. So, multi-representation is needed in fractional problem solving. This study is to describe students’ ability of multi-representation in solving fraction problem. The sample of this study is the VII-B grade students of a state junior high school in Munjungan city, East Java. There are eight classes from A to H, VII-B was chosen purposively. There were 10 boys and 12 girls in VII-B. Multi-representation test was given to each student. Three volunteer were chosen as our respondents. The semi-structured interview was utilized to investigate the process and students conceptual of fraction. This study shows that the students still have difficulties to represent fraction. The students were success to solve model representation, but they have difficulty to solve fraction in number line. The error in representation on addition and subtraction of fraction problem shows that student did not understand fraction concept well. Student ability on multi-representations should be conducted through exercise continually.
Relationship of Teacher’s Content Knowledge on Fraction Topic Toward Student Performance
Authors: Kutub A H W , Wijayanti P , Manuharawati  
Published: December 2019

Abstract
The aim of this study was to describe the relationship between teacher content knowledge and student performance in Fraction. This study used the mixed method that provided Content Knowledge test for fifteen teachers who taught the seventh class. The test consists of multiple choices to measure facts and procedures, knowledge of concepts and relationships, and knowledge of generalization. The study was divided into two phase, Quantitative phase and Qualitative phase. The Quantitative phase, teachers were mapped in two different levels, low and high based on score of Content Knowledge test. Two samples were classified into low level and high level. Furthermore, two groups/classes of the teacher samples were analyzed using Chi-Square test to investigate the relationship between teachers and student performance. The Qualitative phase of the study were included into three stages: (1) teacher interview, and (2) Student Problem solving, (3) description of the relationship of teacher’s content knowledge and student learning performance. The results of the study showed that the Teachers content knowledge in Fraction were affected to student performance, in addition, there were also similarities in the pattern of student performance tests on fraction and the teacher’s answers based on the results of the CK test.
Creative Mathematical Reasoning of Prospective Teachers in Solving Problems Reviewed Based on Working Memory Capacity
Authors: Palengka I , Juniati D , Abadi  
Published: December 2019

AbstractReasoning requires logical thinking in solving problems, and working memory capacity becomes something important. This study aimed at investigating the creative mathematical reasoning of prospective teachers in solving problems reviewed based on working memory capacity. This research was qualitative. The study conducted at Indonesian Christian University of Toraja to Mathematics Education study program students. The selection of research subjects was done by giving operation span (O-SPAN) assignments to select 1 student with a high category of working memory capacity and 1 student with a low category of working memory capacity. Then they were given a creative mathematical reasoning test and interview. Based on the data analysis, it obtained that the creative mathematical reasoning of prospective teachers in solving problems on the research subject who had low working memory capacity showedcreativityandplausibilitycriteria but it did not showanchoringbecause he could not provide arguments that supported the selection of strategies based on mathematics. Furthermore, creative mathematical reasoning of prospective teachers in solving problems on the research subject who had high working memory capacity met the three criteria for creative mathematical reasoning, namelycreativity, plausibility and anchoring.
Student Teachers’ Construction of Mathematical Theorem of Set and Cardinality
Authors: Palupi Evangelista Lus Windyana , Rosyidi Abdul Haris , Putri Hani Rizkia 
Published: December 2019

AbstractConstructivists suggest that teachers should guide and facilitate their students in reinventing and or reconstructing mathematics concepts as in reconstructing a theorem. A theorem in mathematics holds a vital role as a fundamental aspect in building the mathematics itself. Hence, students must learn and acquire this ability. Furthermore, by reconstructing a theorem, students not only learn about the theorem but also learn about problem-solving since the theorem that should be reconstructed can be presented as a problem. In which, this skill is needed and promoted in the 21st century. Hence, the teacher has to be able to reconstruct and prove their construction of theorem. However, many studies were focused on investigating students’ mathematical proof ability, not on the ability to reconstruct a theorem. This study is aimed to investigate mathematics undergraduate students’ ability to reconstruct and prove a theorem. A problem to make a general statement regarding the numbers of all possibility of the cardinality of A B, with A, B is set, and n(A) is a and n(B) is b, is given to 60 undergraduate students who are majoring mathematics education. The statement then is analyzed and categorized into 0 to 5 based on the developed framework. The result shows that most students’ answers (29 answers) are categorized as an incomplete or irrelevant theorem (level 0), while only seven answers can be categorized as level 5 (well structured). As for level 2, 3, and 4, there are 13, 8, 3 answers representatively. Also, there is no student answer, which is categorized as level 1. The mistakes occur because students do not fully understand the mathematics notion. Then, the theorem made is different from the one that is asked, the given condition mentioned by the students is not general enough (does not represent all cases); the conclusion made is false. However, no conclusion is unrelated to the condition.
The Performance of Prospective Teachers in Interpreting Graphs on context-based tasks
Authors: Hidayat D , Siswono TYE , Hartono S , Prihartiwi NR , Kohar AW 
Published: December 2019

Abstract
Graphing ability facilitates students to understand and to connect graphs of data with real-world situations. This ability related to mathematical competencies such as logical thinking and visual representation. One aspect of graphing ability that is important for the student to get meaning from the graph is the interpreting graph. The purpose of this study is to investigate the performance of prospective teachers in interpreting graphs on context-based tasks. This study uses a descriptive-explorative method involving 24 prospective teacher participants at the Universitas Negeri Surabaya. This article presents the performance of prospective teachers’ interpreting graph abilities based on five levels of graph interpretation by Aoyama. The prospective teachers’ graph interpretation is explained along with the difficulties.
The Effectiveness of the Methods and Approaches of ESD for 2030 Sustainable Development Goals; From Analysis of the Questionnaire Survey to the School Teachers
Authors: Icihnose T 
Published: December 2019

Abstract
ESD is a key element of quality education. Its cross-cutting competencies in cognitive, socio-emotional and behavioural dimensions of learning bear relevance to all areas of education. (UNESCO Executive Board 20 February 2019). This study, the result of four years of research in 279 primary and secondary schools in Japan, reveals that in integrated study periods, and with the engagement of local human resources, an increase of activities across different classrooms and grades are a clear result of enhanced ESD and students’ collaboration, cooperativeness, cooperative attitude, and ability to communicate are interconnected. From a pluralistic perspective of ESD, teaching students to confront tensions and conflicts and tackling issues with no single answer seems to be difficult. Since the ESD curriculum has been constructed through whole-school educational activities in Japan by linking it with other subjects and areas, utilizing integrated study periods, it is important to examine approaches to understanding the effectiveness of a whole-school approach of ESD.
Understanding the Nature of Science Through a Content Analysis of Dynamic Fluid: Voices of Pre-Service Physics Teachers
Authors: Suprapto N , Mubarok H , Adam A S 
Published: December 2019

Abstract
Understanding the Nature of Science (NOS) is useful for pre-service, novice, and senior teachers. The specific purposes of this research were analysing the reasoning of NOS among Pre-service Physics Teachers’ (PSPTs) regarding the fact, concept, principle, hypothesize, law, and theory of dynamic fluid, and analysing these NOS variables based on gender, GPA, and score of Philosophy of Science course. This research utilised a mixed-method study, descriptive-interpretive approach with supporting by quantitative analysis of the NOS in relating to PSPTs voices on dynamic fluid. A content analysis was considered in helping the researcher to better comprehend the process of constructing meaning. The study involved of a written questionnaire and followed by a semi-structured interview. A number of thirty one (31) PSPTs in public university in Surabaya, Indonesia were invited to complete the questionnaire form and joined a semi-structured interview. The PSPTs’ voices were categorised into four levels: dissatisfied (naïve), intelligible, plausible, and fruitful that represents the levelling of reasoning. The findings indicated the distribution of PSPTs’ reasoning in dynamic fluid concept varied from the level of dissatisfied to fruitful. PSPTs female performed better in reasoning of NOS than male of dynamic fluid. Moreover, PSPTs whose GPA is better also performed better in reasoning of NOS. Finally, the score of course had also in line with the level of reasoning of NOS.