Authors:Arif Fatahillah, Azza Liarista Anggraini, Susi Setiawani Pages: 131 - 142 Abstract: There is a deadly cardiovascular disease that can cause swelling of the Abdominal Aorta. This disease is known as Abdominal Aortic Aneurysm (AAA). AAA is believed to be a degenerative process caused by genetic factors, gender, body weight, and age. Changes in collagen and elastin in the aortic wall are the cause of the degeneration process. Therefore, it will cause dilatation of the aortic wall. Swelling of the aortic blood vessels will affect the blood flow velocity in the aortic blood vessels. This research aims to analyze the velocity of blood flow in the Abdominal Aortic Aneurysm based on swelling diameter, proximal neck length, and aneurysm channel length using Computational Fluids Dynamics (CFD). The blood flow velocity was modeled using mathematical language based on mass continuity equations and momentum equations. Then the finite volume method was one method to solve the mathematical model. MATLAB and ANSYS FLUENT software were used to simulate the velocity of blood flow analysis. The results of the research were shown that the larger the diameter and swelling channel length, the smaller the velocity of blood flow produced. Then, the greater the length of the proximal neck, the faster the resulting blood flow will be. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.9928 Issue No:Vol. 5, No. 2 (2022)

Authors:Slamet Mey Rizalno, Sigid Edy Purwanto Pages: 143 - 154 Abstract: This research has a background, namely the ability to think mathematical creatively. This is because students pay less attention to the mathematics learning process. This will have an impact on the ability to think creatively in mathematics so that it will not develop properly. Adversity Quotient is the creative thinking ability of a student who can solve problems well if supported by good solving skills. The purpose of this research is to see the creative thinking ability of students in terms of the adversity quotient. The method in this research is descriptive qualitative research with an interview process. Data collection in this research is in the form of instrument questions that contain indicators of creative thinking, namely fluency, flexibility, originality, and elaboration. The results of the research were seen from the results of the answers to the questions on the mathematical creative thinking ability instrument and the adversity quotient, which contained that students had three types of adversity quotient, namely Climbers, Campers, and Quitters. Subjects with indicators of fluency, flexibility, originality, and elaboration with the Climbers type were able to solve the questions according to each indicator, the Campers type students were able to solve the questions correctly but were still lacking in preparing answers, and the Quitters type students still did not understand how to solve the questions so that the answer was wrong. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.12642 Issue No:Vol. 5, No. 2 (2022)

Authors:Ummu Wachidatul Latifah, Sugiyarto - Surono, Suparman suparman Pages: 155 - 168 Abstract: The Human Development Index (HDI) is very important in measuring the country's success as an effort to build the quality of life of people in a region, including Indonesia. The government needs to make groupings based on the needs of a city/district. To facilitate data grouping based on the similarity of existing characteristics, it is necessary to have a data grouping method, namely the clustering technique. There are several algorithms that are often used in clustering techniques, namely K-Means and Fuzzy C-Means. Each algorithm has advantages and disadvantages. Therefore, in this research, the comparison of the best clustering algorithms will be discussed. The purpose of this research is to compare the K-Means and Fuzzy C-Means algorithms in the grouping of Regencies/Cities in Central Java Province in 2021 based on the Human Development Index (IPM) indicator. The method used is descriptive qualitative. The data used is obtained from the Central Java Statistics Agency, which is in the form of the Central Java Province HDI indicator in 2021 which consists of 35 Regency/City members and has 4 variables, namely Life Expectancy (AHH) (X1), Expectation of School Years (HLS) (X2), Average Length of School (RLS) (X3) and Expenditure Per Capita (X4). The results showed that after a comparative analysis with the standard deviation ratio method, the FCM clustering method was better than the K-Means method. The value of the FCM standard deviation ratio is 0.460093 and the K-Means standard deviation ratio is 0.473601. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.12204 Issue No:Vol. 5, No. 2 (2022)

Authors:Muhammad Wakhid Musthofa, Malahayati Malahayati Pages: 169 - 176 Abstract: There is a similarity in concept between 'aul and the definite integral. 'Aul deals with the issue of the quantity of inheritance which must be divided into smaller quantities in order to be handed over to the heirs, while definite integral relates to the problem of calculating the broad of an area by dividing the area into smaller ones, followed by summing up the broad of each area. Achmad Yani used the definite integral to solve the problem of 'aul. But, in our opinion, the concept he used was wrong and there were still some errors in the construction that he described. This article aims to provide some corrections to such errors and provide some notes that as far as our research, the definite integral has not been able to be used in solving the problem of 'aul yet. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.12417 Issue No:Vol. 5, No. 2 (2022)

Authors:Randhi Nanang Darmawan Pages: 177 - 186 Abstract: The development of the tourism industry in Banyuwangi before the COVID-19 pandemic was quite rapid, including the food and beverage industries, but when the COVID-19 pandemic hit, it impacted the number of tourists in Banyuwangi decreasingly, and this had a significant impact on various economic sectors. However, interesting data showed that the number of food and beverage industries can be said to be stable during COVID-19, the trend indicated that there will be an increase in the number of the food and beverage industries after the pandemic subsides. In line with the Banyuwangi Rebound program, it is likely that the quantity of food and beverage industries will increase. Then, based on this phenomenon, the aim of this research was to forecast the number of food and beverage industries in Banyuwangi using the trend-adjusted exponential smoothing method. The accuracy and feasibility of forecasting results were measured based on the Mean Absolute Percentage Error (MAPE) and Tracking Signal (TS) values. The obtained forecasting model will be used to forecast the growth of the food and beverage industries in 2022, 2023, 2024, and 2025. The results of this research obtained that a forecasting model , with the results of forecasting the number of the food and beverage industries in Banyuwangi were 547 in 2022, 561 in 2023, 576 in 2024, and 589 in 2025. The average MAPE value for each forecasting result was 37.87% and the average TS value was 0.225, so it was included in the category of feasible to be used. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.12782 Issue No:Vol. 5, No. 2 (2022)

Authors:Hilda Amalia, Hella Jusra Pages: 187 - 196 Abstract: This research aims to analyze the mathematical problem-solving ability of students in terms of self-regulated learning. The method used in this research is the qualitative descriptive method. There are 4 indicators of problem-solving ability in this research, namely understanding the problem, formulating the problem, solving the problem, and re-examining the answers. The four indicators of problem-solving ability can be met by subjects who have a high self-regulated learning category. Subjects with medium self-regulated learning category were only able to fulfill 3 indicators of problem-solving ability. Meanwhile, subjects with low self-regulated learning were only able to fulfill 2 indicators of problem-solving ability. The results showed that the ability to solve problems with high categories was owned by subjects with high self-regulated learning. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.12893 Issue No:Vol. 5, No. 2 (2022)

Authors:Hisna Tiana, Sigid Edy Purwanto Pages: 197 - 210 Abstract: This research aims to justify students' mathematical problem-solving abilities on the material of the System of Linear Equations in Two Variables in terms of the Hippocrates-Galenus personality type. This research method is included in qualitative descriptive research. The technique used is purposive sampling. The instruments in this research were personality-type questionnaires, mathematical problem-solving ability tests, and interviews. The triangulation technique was obtained by comparing the results of the student's problem-solving ability tests on the material of the System of Linear Equations in Two Variables with the results of the interviews. The results of this research are that the sanguine did not fulfill the aspect of re-examining all the stages that have been carried out, the choleric did not meet the problem-identifying aspect, the melancholy fulfilled the four aspects of mathematical problem-solving, and the phlegmatic did not meet two aspects, namely solving the problem according to the plan and re-examining all the stages that have been completed. Each student with each personality type according to Hippocrates-Galenus has different thoughts and steps to solve mathematical problems, therefore both educators and students who have different mindsets are expected to understand different thoughts. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.13050 Issue No:Vol. 5, No. 2 (2022)

Authors:Dwi Haryanto, Fida Fathiyah Addini Pages: 211 - 222 Abstract: In this research, a Markov chain model was constructed from the conditions that might be experienced by the people during the Delta or Omicron variant of the COVID-19 pandemic. This condition is divided into 3 states; "0" indicates a healthy condition, "1" indicates the state of being infected with COVID-19, and "2" indicates the death state. Furthermore, from the model obtained, a transition probability matrix is made to determine the transition probability value and calculate the average number of steps needed to get to the death state. From the results of the analysis, the probability of transition to a state of death is 1. This shows that a person will surely die from being healthy or positive for COVID-19 within a certain time. During the Delta variant of the COVID-19 pandemic, the average time that a person reaches a death state from a healthy state is 34.02 years. Meanwhile, the average time taken for someone infected with the Delta variant of COVID-19 to death is 33.79 years. During the Omicron variant of the COVID-19 pandemic, the average time that a person reaches a death state from a healthy state is 37.63 years. Meanwhile, the average time taken for someone infected by the Omicron variant of COVID-19 to death is 37.41. This shows that the average age of a person infected with the Delta variant of COVID-19 has decreased by 2.79 months, while the average age of a person infected with the Omicron variant of COVID-19 has decreased by 2.70 months. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.13567 Issue No:Vol. 5, No. 2 (2022)

Authors:Fraulein Intan Suri, Bambang Sri Anggoro, Komarudin Komarudin, Rohmah Romadhona Fahmi Pages: 223 - 234 Abstract: Media Islamic Math e-Comic is a mathematical comic with Islamic nuances that has mathematical problem solving with clear illustrations and problem-solving methods according to indicators that can improve students' mathematical communication skills. This study aims to determine how much the increase in mathematical communication skills in the use of Islamic Math e-Comic media on the subject of flat side space for class VIII. The media is developed through stages in the ADDIE model (Analysis, Design, Development, Implementation, and Evaluation). This type of research is Quasy Experiment by giving pretest and posttest questions on small-scale tests and large-scale tests. Then, the effectiveness test of the use of Islamic Math e-Comic media was carried out using the Effect Size test, obtaining results of 0.53 with the "medium" criteria. This shows an increase in the value obtained by students after using the Islamic Math e-Comic media on the flat side space building material. PubDate: 2022-08-30 DOI: 10.24042/djm.v5i2.12910 Issue No:Vol. 5, No. 2 (2022)