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Hukmah Hukmah, Syamsuddin Toaha, Jeffry Kusuma
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 67-77;

The Intra-guild predation model is an interaction between three species where two of them compete and prey on each other for the same resource. This study considers the stage structure of prey on and combines Beddington-DeAngelis and Holling type I as functional responses in the model. Furthermore, the equilibrium point and stability of the model will be analyzed. The numerical result at the equilibrium point shows that the solution converging toward the equilibrium point so that the population is stable and will not become extinct with increasing time. In addition, the population tends to be stable when the density of prey is larger than the predator.
Samy Abdelmoezz, Salah M. Mohamed
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 1-11;

We introduce and study the Kumaraswamy Lindely Distribution (KLD) model, which has increasing, decreasing, upside-down bathtub and bathtub shaped hazard functions.. We perform a Monte Carlo simulation study to assess the finite sample behavior of the maximum likelihood estimates of the parameters. We define a new regression model based on the new distribution. The new regression was applied to data from the Egyptian stock exchange in the period of (2015-2019). Finally, we study some properties of regression Residual analysis The martingale residual, Deviance component residual.
Nur Suci Ramadhani, Toaha Toaha, Kasbawati Kasbawati
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 12-21;

In this paper, the modified Leslie-Gower predator-prey model with simplified Holling type IV functional response is discussed. It is assumed that the prey population is a dangerous population. The equilibrium point of the model and the stability of the coexistence equilibrium point are analyzed. The simulation results show that both prey and predator populations will not become extinct as time increases. When the prey population density increases, there is a decrease in the predatory population density because the dangerous prey population has a better ability to defend itself from predators when the number is large enough.
Erna Nurmawati, Robby Hasan Pangaribuan, Ibnu Santoso
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 22-30;

One way to deal with the presence of missing value or incomplete data is to impute the data using EM Algorithm. The need for large and fast data processing is necessary to implement parallel computing on EM algorithm serial program. In the parallel program architecture of EM Algorithm in this study, the controller is only related to the EM module whereas the EM module itself uses matrix and vector modules intensively. Parallelization is done by using OpenMP in EM modules which results in faster compute time on parallel programs than serial programs. Parallel computing with a thread of 4 (four) increases speed up, reduces compute time, and reduces efficiency when compared to parallel computing by the number of threads 2 (two).
Andi Utari Samsir, Syamsuddin Toaha, Kasbawati Kasbawati
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 42-54;

This article discusses the optimal control of a mathematical model on smoking. This model consists of six population classes, namely potential to become smoker snuffing class irregular smokers regular smokers temporary quitters and permanent quitters The completion of this research uses the Pontryagin minimum principle and numerically using the forward-backward Sweep method. Numerical simulations of the optimal problem show that with the implementation of education campaigns and anti-nicotine medicine, the smokers can be decreased more quickly and the smoking population who quit permanently can be increased. The implementation of both through large amounts needs to be done from the beginning. The use of control in the form of education campaigns is of great value until the end of the research period means that it needs to be done continuously to reduce the number of smokers in the population.
Salsavira Salsavira, Jahra Afifah, Fiqih Tri Mahendra, Lathifah Dzakiyah
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 31-41;

Early marriage has become an important issue in Indonesia. Even though the rate of early marriage shows a decline until 2020, the number still makes Indonesia become the country with the second highest early marriage in Southeast Asia. Early marriage that occurs can hinder the achievement of the Sustainable Development Goals (SDG) and can have an impact on the Human Development Index. The existence of a relationship between early marriage and HDI encourages researchers to conduct studies that aimed at examining the effect of the prevalence of early marriage on HDI in each district/city in Indonesia on 2020. This study uses the Geographically Weighted Logistic Regression (GWLR) analysis method with the data sourced from the National Socio-Economic Survey (SUSENAS) raw data in March 2020 and publication data on the website of The Central Bureau of Statistics. The results of the analysis found that the prevalence of early marriage has a negative and significant effect in several districts/cities in the Provinces of Aceh, North Sumatra, West Sumatra, Riau, Jambi, South Sumatra, Bengkulu, Lampung, Bangka Belitung Islands, Riau Islands, West Java, Central Sulawesi, South Sulawesi, Southeast Sulawesi, Maluku, and West Papua. This research is expected to be a recommendation for the government and community organizations to conduct socialization regarding the maturity age of marriage and the adverse effects that can be caused by early marriage.
Salsabila Ammari, Muh Nur, Naimah Aris
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 93-101;

This paper discussed about the proof of the fixed point theorem on the standard 2-normed spaces by using completeness. The completeness of the standard 2-normed spaces is shown by defining a new norm. Two linear independent vectors on standard 2-normed spaces are used to define the new norm, namely which has been shown to be equivalent to standard norm.
Melisa Arumsari, Sri Wahyuningsih, Meiliyani Siringoringo
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 78-92;

The Singular Spectrum Analysis (SSA)-Autoregressive Integrated Moving Average (ARIMA) hybrid method is a good combination of forecasting methods to improve forecasting accuracy and is suitable for economic data that tends to have trend and seasonal patterns, one of which is inflation data. The purpose of this study is to obtain the results of inflation forecasting for East Kalimantan Province in 2021 using the SSA-ARIMA hybrid model. The results of the inflation forecasting for East Kalimantan Province in 2021 using the SSA-ARIMA(1,1,1) hybrid model overall experienced an increase and the highest inflation in 2021 occurred in December of 0.92% with a forecasting accuracy level based on the Root Mean Square Error (RMSE) was 0.069399 and Mean Absolute Percentage Error (MAPE) was 32.61084%
L.M. Jamaluddin Al Afgani
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 121-129;

The Zero-Inflated Generalized Poisson (ZIGP) distribution is a case-based distribution where the discrete data has a large number of zeros and an overdispersion occurs, i.e. the variance is greater than the mean value. The purpose of this study is to determine the Exponential Weight Moving Average (EWMA) control chart with the assumption that the data has a Zero-Inflated Generalized Poisson (ZIP) distribution. The results show that the ARL value of the ARL ZIGP EWMA control chart has better accuracy when compared to when using the ZIP EWMA control chart on ZIGP distributed data. This is indicated by the smaller ARL value compared to the ZIP EWMA control chart, namely when φ = 1.4, and φ = 0.6. So that the ARL ZIGP EWMA control chart has a fairly good accuracy in detecting out of control conditions for ZIGP distributed data. In addition, the modified ARL shows the same values ​​before and after the modification for the underdispersion data and shows a larger or negative value for the overdispersion data. This can eliminate or reduce errors in analyzing the accuracy of the control chart.
Aprilia Lutviana Dewi, Budyanra Budyanra
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 102-120;

Traffic accidents among students are one of the problems experienced in the Greater Jakarta area. World Health Organization (WHO) stated that younger drivers are the most vulnerable group to experiencing traffic accidents, including the students. According to Badan Pusat Statistik (BPS), it was estimated that as many as 301,120 Jabodetabek commuters had experienced a traffic accident in 2019. Moreover, 13 to 14 out of the 100 commuters who had experienced traffic accidents are student commuters or commuters with the main activities going to school. Therefore, this study was conducted to determine the factors that affect the accident status of Jabodetabek student commuters in 2019 and their odds ratios by using the 2019 Jabodetabek Commuter Survey data. The analytical method used is a binary logistic regression with the parameter estimation method using penalized maximum likelihood estimation (PMLE). And the results showed that the variables of age, gender, last education, mode of transportation, classification of the area of residence, distance traveled, and the area of the activity had a significant influence on the accident status of Jabodetabek student commuters. Furthermore, student commuters who live in rural areas have the highest tendency to experience a traffic accident.
Nur Annisa Fitri, Memi Nor Hayati, Rito Goejantoro
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 141-149;

Cluster analysis has the aim of grouping several objects of observation based on the data found in the information to describe the objects and their relationships. The grouping method used in this research is the Fuzzy C-Means (FCM) and Subtractive Fuzzy C-Means (SFCM) methods. The two grouping methods were applied to the people's welfare indicator data in 42 regencies/cities on the island of Kalimantan. The purpose of this study was to obtain the results of grouping districts/cities on the island of Kalimantan based on indicators of people's welfare and to obtain the results of a comparison of the FCM and SFCM methods. Based on the results of the analysis, the FCM and SFCM methods yield the same conclusions, so that in this study the FCM and SFCM methods are both good to use in classifying districts/cities on the island of Kalimantan based on people's welfare indicators and produce an optimal cluster of two clusters, namely the first cluster consisting of 10 Regencies/Cities on the island of Kalimantan, while the second cluster consists of 32 districts/cities on the island of Borneo.
Yanuwar Reinaldi, Nurissaidah Ulinnuha, Moh. Hafiyusholeh
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 130-140;

Community welfare is one of the important points for a region and is also the essence of national development. The welfare of the people in Indonesia is fairly unequal, especially in East Java. To be able to map an area to the welfare of its people in East Java, one way that can be used is to use clustering. The hierarchical clustering method is one of the clustering methods for grouping data. In hierarchical clustering, single linkage, complete linkage, and average linkage methods are suitable methods for grouping data, which will compare the best method to use. The results of the calculation show that the average linkage method with three clusters is the best calculation with a silhouette index value of 0.6054, with the 1st cluster there are 23 regions, namely the city/district with the highest community welfare, the 2nd cluster there are 11 regions, namely cities/districts with moderate social welfare, and in the third cluster there are 4 regions, namely cities/districts with the lowest community welfare.
Muhammad Qolbi Shobri, Ferra Yanuar, Dodi Devianto
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 150-160;

At the end of 2019 the world was shocked by a new disease caused by SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2). The disease is called Covid-19 (Coronavirus Disease). The mortality rate due to disease is increasing every day. In Indonesia as of April 2021, confirmed Covid-19 patients who died reached 42,530 patients, seeing the high mortality rate of Covid-19 patients so it needs to be studied further so that the risk of death of these Covid-19 patients can be minimized. This research utilizing binary logistic regression with Bayesian method parameter estimation. In this study, the predictor variables used were in the form of categories that each category in the predictor variables was assumed to have the same risk of death risk of Covid-19 patients. The results of this study indicate that the number of comorbids has a significant effect on the risk of death of Covid-19 patients, the more the number of comorbids suffered by the patient, the higher the risk of death of the patient. The accuracy of this method in classifying data is 84.68%.
Miftahuddin Miftahuddin, Wanda Sri Noviana
Jurnal Matematika, Statistika dan Komputasi, Volume 18, pp 55-66;

Sea surface temperature (SST) is one of the attributes of the world climate system and global warming. The relationship between SST and other climate parameters can be represented in a linearity approach. Through this approach, SST variability shows monthly and yearly effects. Information on these two time effects is important for knowing the period of peak effect as well as other statistical measures in the linear fitting model. The models used include transformation and without covariate transformation, interaction and without covariate interaction, and with centering and with the addition of time covariates in the model. The linear fitting model chosen as the basis for construction is a model with a combination effect of covariate interaction and transformation giving an increase in the magnitude of multiple R2 (56.62%) and adjusted R2 (56.13%) respectively 0.31% and 0.43%. This indicates that the time covariate has a very strong significant effect on the model compared to the continuous covariate. In general, the model has a statistical significance of p-value < 2.2e-16, as well as for the time covariate. However, because the model has an autocorrelation and a large AIC value, this effect is removed by means of an autoregressive moving average. The obtained linear fitting model for SST data is the model with AIC 403.2987.
Rahmahdani Japri
Zona Laut : Jurnal Inovasi Sains Dan Teknologi Kelautan pp 26-34;

Kapal general cargo adalah kapal yang mengangkut bermacam-macam muatan berupa barang. Barang yang diangkut biasanya merupakan barang yang sudah dikemas. Ukuran utama kapal didapatkan dengan menggunakan metode pembanding regresi yang didasarkan pada data 2 kapal pembanding yang di dapat dari korea register of shipping (KRS). Pada penelitian ini direncanakan desain konstruksi profil kapal general cargo yang dirancang sesuai dengan ukuran utama kapal yang sesui dengan aturan Rules Biro klasifikasi Indonesia. Dari hasil perencanaan didapat untuk kapal berkapasitas 17000 DWT didapat dimensi kapal dengan length over all (LOA) 153,45 m, length between prependiculars (LBP) 144,24 m, Length on load waterline (LWL) 147,85 m, lebar (B) 25,27 m, tinggi (H) 13,5 m, sarat (T) 9,52 m, kecepatan (V) 14,75 Knot. Metode pembanding ini memudahkan perancangan kapal dengan hasil yang lebih akurat.
Windi Widianingrum, Juswan Sade, Habibi Palippui
Zona Laut : Jurnal Inovasi Sains Dan Teknologi Kelautan pp 18-25;

Korosi adalah salah satu penyebab kerusakan yang umum terjadi pada mooring buoy akibat adanya oksidasi pada permukaan pelat baja. Tujuan dari penelitian ini adalah untuk mengetahui kebutuhan dan peletakan proteksi katodik serta biaya yang dibutuhkan dalam pengadaan proteksi katodik pada mooring buoy dengan menggunakan aturan BKI (Biro Klasifikasi Indonesia) dan DNV (Det Norske Veritas Industry Norway). Dalam sistem proteksi katodik terdapat dua metode proteksi katodik yaitu Sacrificial Anode Cathodic Protection (Anoda Korban) dan Impressed Current Cathodic Protection (ICCP). Pada penelitian ini digunakan metode anoda korban karena instalasi lebih sederhana sehingga tidak memerlukan keahlian khusus dan penghubung anoda telah terlindungi secara katodik. Mooring buoy dengan tinggi 2,380 m, berdiameter 3,200 meter dengan umur desain proteksi katodik yaitu 5 tahun. Anoda yang digunakan pada penelitian ini adalah anoda dengan tipe Longated flush-mounted Z9.0H1 (Welded Type) dengan dimensi 355 x 85 x 45 mm. Dari hasil penelitian ini didapatkan total massa anoda yang dibutuhkan untuk memproteksi mooring buoy adalah 48 kg dengan jarak pemasangan antar anoda pada pelat lambung topside adalah 2,000 m dan pada pelat bottom swim lambung adalah 3,000 m serta estimasi biaya yang dibutuhkan dalam pengadaan proteksi katodik mooring buoy adalah Rp. 7.487.075.
Ashari Wicaksono, Nike Ika Nuzula
Zona Laut : Jurnal Inovasi Sains Dan Teknologi Kelautan pp 1-5;

Indonesia merupakan negara kepulauan yang tidak dilewati secara langsung oleh siklon tropis. Akan tetapi, dampak yang ditimbulkan oleh adanya siklon tropis seperti gelombang tinggi, angin kencang yang berdampak pada wilayah pesisir pada utamanya. Siklon tropis Surigae merupakan salah stu siklon tropis yang dilaporkan terbentuk di samudera pasisfik yang berdekatan dengan perairan Indonesia bagian utara yang berbatasan dengan selat Sulawesi. Penelitian ini dilakukan dengan cara menganalisis data SLA dan ADT untuk mendapatkan model dinamika dan anomali muka laut pada saat kondisi terjadinya siklon tropis Surigae. Hasil model menunjukkan bahwa dari analisis data SLA didapatkan ketinggian rata-rata 0.1 - 0.2 meter, dan untuk ADT didapatkan rata-rata ketinggian 0.9 - 1.1 meter, dan hasil model juga memperlihatkan terjadinya fenomena arus eddi di timur negara Filipinan selama siklon tropis Surigae berlangsung. Data SLA dan ADT memiliki kemampuan dalam mendeteksi perubahan muka laut akibat adanya siklon tropis, dan dapat digunakan juga untuk mendeteksi pergerakan arus dan fenomena arus eddi.
Yusman Yusman
Zona Laut : Jurnal Inovasi Sains Dan Teknologi Kelautan pp 6-10;

Pertemuan lempeng Indo-Australia, Lempeng Eurasia, dan Lempeng Pasifik membuat kondisi geologis Indonesia menjadi tidak stabil sehingga rawan terjadi gempa. Kabupaten Majene termasuk wilayah rawan gempa sehingga dianjurkan bangunan yang tahan gempa. Tujuan dari penelitian ini adalah untuk mengetahui dan mengklasifikasikan jumlah rumah yang terdampak gempa serta penyebab tingginya tingkat kerusakan. Metode yang digunakan adalah metode survei dan wawancara. Proses survei dilakukan dengan mengamati rumah warga dan mengklasifikasikan tingkat kerusakan berdasarkan petunjuk teknis yang dikeluarkan oleh Tim Balai Litbang Bahan & Struktur Bangunan Kementerisan PUPR tahun 2019 . Dari hasil survei diperoleh rumah rusak berat berjumlah 1.713, rusak sedang berjumlah 1.060 dan rusak ringan berjumlah 1.107. Dari hasil survei dan wawancara dipeoleh bahwa kondisi struktur bangunan rumah pada umumnya tidak sesuai dengan panduan pembangunan perumahan dan pemukiman oleh Tim Balai Litbang Bahan & Struktur Bangunan Kementerisan PUPR. 2016 yaitu tidak memiliki sloof, ring balok atau kolom sehingga mengakibatkan presentasi kerusakan rumah lebih tinggi.
Abrari Noor Hasmi, Alamsyah Alamsyah, Asram Dio Pratama
Zona Laut : Jurnal Inovasi Sains Dan Teknologi Kelautan pp 11-17;

Rudder adalah perangkat untuk mengubah arah kapal dengan mengubah arah arus air yang mengakibatkan manuver pada kapal. Rudder ditempatkan diujung belakang lambung kapal/ buritan belakang baling-baling. Jenis umumnya banyak dipakai adalah tipe konvensional namun adapun jenis rudder selain jenis konvesional, yaitu jenis fishtail. Penelitian ini bertujuan untuk menganalisa perbedaan performa antara rudder konvensional dan rudder fishtail terhadap nilai Drag Force dan Lift Force. Metode yang digunakan adalah persamaan Clark dengan bantuan aplikasi berbasis CFD untuk mengetahui performa yang dihasilkan pada saat kapal Drag Force dan Lift Force dengan memvariasikan sudut belok 5°, 10° dan 35°. Hasil penelitian didapatkan rudder konvensional memiliki tingkat keefektivitas drag force dan coefficient drag yang lebih baik dibandingkan rudder fish tail, sedangkan pada rudder fish tail memiliki tingkat memiliki tingkat keefektivitas lift force dan coefficient lift yang lebih baik dibandingkan rudder konvensional.
Jaiyen Pagau, Pahrizah Puji Anugrah
Zona Laut : Jurnal Inovasi Sains Dan Teknologi Kelautan pp 40-46;

Salah satu proses yang kritikal ketika fabrikasi offshore yaitu proses transfer offshore module (Top Side) dari atas jetty ke PT. Indusri Kapal Indonesia merupakan perusahaan yang berusaha dalam bidang pembuatan kapal dan perbaikan kapal, Perusahaan ini telah menerapkan sistem manajemen lingkungan, keselamatan dan kesehatan kerja. terdapat hubungan antara faktor manusia dengan kecelakaan kerja. Karena itu diperlukan suatu penelitian yang bertujuan untuk mengidentifikasi faktor-faktor manusia yang menyebabkan kecelakaan kerja, mempelajari karakteristik faktor manusia pada responden terhadap kecelakaan kerja dan menganalisis pengaruh faktor manusia terhadap kecelakaan. Penelitian ini akan menerapkan metode kuesioner sebanyak 30 respoden untuk mengumpulkan data primer dari beberapa responden dan merupakan penelitian cross-sectional study (pendekatan silang). Hasil penelitian menunjukkan terdapat 15 respoden(50%) pekerja mengalami cedera ringan, 3 respoden (10%) pekerja perna mengalami kecelakaan berat, dan 12 respoden (40%) pekerja tidak pernah mengalami cedera. Diharapkan perusahaan memberikan informasi yang cukup kepada pekerja tentang pentingnya K3, lebih intensif dalam memberikan program pelatihan (training), mengadakan kontes-kontes keselamatan dengan memberikan reward bagi pekerja, serta pekerja mampu meningkatkan kedisiplinan dalam penggunaan APD dan meningkatkan kesadaran untuk menciptakan lingkungan kerja yang aman.
Sugeng Marsudi, Alya Ramadani
Zona Laut : Jurnal Inovasi Sains Dan Teknologi Kelautan pp 35-39;

Kebutuhan daya listrik antara desain awal kapal dengan keadaan yang ada di lapangan. Pada akhirnya, dapat dibuktikan secara teoritis bahwa perencanaan sistem kelistrikan di kapal dapat diterapkan secara nyata dan sesuai dengan ketentuan yang berlaku sehingga pada saat pemasangan instalasi listrik di kapal dan tujuan di masa yang akan datang dapat dihandalkan serta kepuasan bagi pemilik kapal. Metode yang digunakan adalah melakukan analisa dan pengolahan data maka akan di dapatkan analisis kebutuhan daya pada pompa kapal cargo. Semua hasil pengolahan data berupa gambar, grafik, serta perhitungan yang diperoleh hasil dari proses tersebut, kemudian dilakukan pengelompokan untuk dianalisa. Dari hasil perhitungan daya pompa terpakai dapat dilihat bahwa daya pompa terbesar dibutuhkan pada saat kapal dalam keadaan darurat dimalam hari yaitu 46,76 Kw, maka besarnya daya ini menjadi standar dalam pemilihan mesin bantu agar kebutuhan daya pada kondisi tersebut dapat dipenuhi
Ji Li, Masaya Nakatsuka
Journal of Asian Rural Studies, Volume 5, pp 98-110;

The purpose of this study is to clarify the barriers and the process of supports obtained in starting the farm-stay businesses with inbound tourism from the perspective of migrants. In- depth interviews on entrepreneurship of farm-stay businesses among local vitalization cooperators (LVC) were conducted, and the following results were found. First, there are two main types of barriers when starting farm-stay businesses namely barriers caused by new businesses start-up and barriers caused by local life. The barriers caused by local life have three aspects: an inadequate understanding of the ways to interact with local residents, insufficient information on community rules, and insufficient agricultural knowledge. The barriers to receiving foreigners include lack of understanding by neighbors, publicity, service and activities supplied, and matching facilities. Second, supports can also be divided into two categories: supports in local life and those in business start-up. The network and trust relationship established with local residents during the first stage of overcoming local life barriers can help overcome the barriers faced when starting businesses. Meanwhile, supports in business start-up deepen the relationship between migrants and local residents, thus playing a supportive role in life stabilization. Third, by analyzing the LVC cases, we conclude that ordinary migrants need ample time to undergo the process of accommodating to local life, thereby building a network and trust with local regions before starting new businesses. This research provides references on the study of starting new businesses in rural areas from the migrants’ views and issues to farm-stay businesses and inbound tourism at the starting phase.
Sérgio Jordão Augusto Ponguane, Bento Mussumbuluco, Nézia Mucavele
Journal of Asian Rural Studies, Volume 5, pp 135-142;

Demand for agricultural land by foreign investors has been increasing in Mozambique over the last years and the Wanbao project is an example. The implementation of this project in Gaza has divided opinions between the government, civil society and academia. This study aims to contribute to the debate on whether Wanbao project can be considered as land grabbing and the extent to which the project contributes to the development of small-scale agriculture in Gaza Province. Data were collected through a semi-structured questionnaire in December 2019 and January 2020, covering a total of 66 household affected by the Wanbao project. The data were analyzed by a descriptive statistic and a cross-check of the Mozambican land law, the available literature on land grabbing and the information collected on the ground from the farmers affected by the project. The results show that the land concession to Wanbao was made without any consideration of customary rights, however, it was found that the contract farming program can increase rice productivity in the short term, but its sustainability remains questionable. Thus, if the Mozambican government intends to transform agriculture through large investments, it must ensure that the concession of land respects customary rights and the companies involved ensure the transfer of technologies in an effective and sustainable manner.
Kazuko Tatsumi
Journal of Asian Rural Studies, Volume 5, pp 111-125;

Rural communities have long endured poverty, and they continue to tackle the problems of depopulation, a declining birth rate, and an aging population in Japan. Some rural communities face a crisis of survival. The question of this study are how sustainable communities in rural areas are being created. This study examine the process by which rural women have transformed the Livelihood Improvement Program (LIP) into a movement. The process was to expand rural women’s activities to enable them to play an active role in their family, women’s groups, and their community. This expansion reflects the effects of the LIP in rural areas. The LIP was started by the Ministry of Agriculture and Forestry in Japan in 1948 to develop self- reliant farmers. The women tried to find solutions to their problems using LIP approaches including problem-solving and the three-by-five cognitive method in group discussions. The LIP was a long-term program and officially ended in 2004. However, the LIP has been continued as a movement for the sustainable development of their community by the women. This study focuses on a case study at the community level involving an update of the LIP program in Yamaguchi Prefecture. The analysis is based on a literature review, secondary and historical data, and fieldwork carried out between 2004 and 2020. From a medium- to long-term viewpoint, their self-confidence improved and they became self-reliant famers. Now women in the older generations are creating employment opportunities through community businesses so that the younger generations may choose to remain in the rural areas in the future. There has been an increasing tendency for young people who moved to the cities to study or work to return to their hometowns. This study found that the most important aspects in susutainable community development are people’s initiative, identity, and pride.
Chrysl Avegeil Vallejo, Cleofe Torres, Ma. Theresa Velasco, Benjamina Paula Flor, Josefina Dizon
Journal of Asian Rural Studies, Volume 5, pp 143-149;

This paper aimed to explain how rice farmers in Sto. Domingo, Nueva Ecija, Philippines managed to properly appropriate flatbed dryers. It also sought to describe the modes of appropriation offlatbed dryers: adoption, adaptation, and peer/group learning. Data were gathered through a survey among 131 rice farmers and key informant interviews. Findings revealed that the rice farmers experimented and modified the features of flatbed dryers to better adapt the technology to their needs. The rice farmers have encountered problems in using the technology but have managed to employ adaptation strategies to address these problems which resulted to peer/group learning among them.
Rizzi Angelica Ternida Dagos
Journal of Asian Rural Studies, Volume 5, pp 90-97;

This study aimed to determine the role of microfinance institutions (MFIs) in alleviating poverty among households of San Jose, Occidental Mindoro. Particularly, this study aimed to: (1) characterize microfinance household clients in San Jose, Occidental Mindoro, in terms of: socio- demographic, economic and communication; (2) determine the driving forces of clients to avail microfinance services; (3) identify the household-clients’ frequently availed/accessed/paid microfinance services; and (4) determine the household clients’ perceived effect of microfinance services in terms of: economic, social and personal. A total of 200 randomly selected household MFI clients, both from rural and urban barangays of San Jose, Occidental Mindoro were interviewed for this study. Descriptive statistics such as mean, weighted mean, frequency and percentage distribution were used in analysing and presenting the data. The results of the study revealed that most of the respondents are female, married and literate. They have other sources of income. Among the most common driving forces of household clients in availing microfinance services are financial security, health-related concerns and education. The frequently availed services of household clients are savings, insurance and loans and their most common microfinance service provider is the Center for Agriculture and Rural Development Incorporated (CARD Bank). The household clients experienced reduced poverty and increased acquisition of assets as economic effect of microfinance services, while they had improved lifestyle and improved relationships with other people as social effects and increased self-confidence and fulfillment as personal effects of microfinance services.
Iboh Andrew Okidim, Lynda Ogechi Egwue, Data Irene Ekine, Eleoke Chikwe Chukuigwe
Journal of Asian Rural Studies, Volume 5, pp 126-134;

Food insecurity is a challenge in developing countries, especially in the rural areas of Nigeria. It remains a global challenge and continues to be a major public policy in Nigeria and other developing nations. Despite these, COVID-19 set in and posed a serious threat to food system and security globally. This study, therefore, assessed the level of food security among the rural farming households and how they cope with the situation during the COVID-19 pandemic. Data for the study were collected primarily from 200 farming households with the use of questionnaires and analysed using descriptive statistics, food security index and Likert scale. The findings showed that the level of food insecurity was very high during the pandemic as 69.5% were food insecure with a high concentration among those with large household size. The widely adopted coping strategies during COVID-19 pandemic among the rural farming households were eating less expensive food (=2.7), reducing rational consumption (=2.68), allowing children to eat first (=2.56), engaging in additional small scale productivity activities (=2.27), skipping meal within a day (=2.26), buying food on credit (=2.05) and borrowing money to buy food (=2.01). The study recommends effective and urgent policy measures which will support rural households’ food availability to boost their food security status. Also, enlightenment of the rural households on the important of modern family planning on their food security status is needed.
Fitriatusakiah Fitriatusakiah, Andi Kresna Jaya, La Podje Talangko
ESTIMASI: Journal of Statistics and Its Application pp 105-114;

The level of poverty in a Regency/city in South Sulawesi in 2017 is different. The grouping of poverty status can be done based on the value of the HeadCount Index (HCI) of South Sulawesi. Factors affecting poverty will differ for each area being observed. The statistical modeling method developed for data analysis by taking into account the location factor is semiparametric Geographical Weighted Logistic Regression (GWLR). The GWLR semiparametric Model consists of parameters that are affected by the location and not affected by the location. The parameter estimator of the GWLR semiparametric model used in this research was obtained using the maximum method likelihood estimation. The result of a semiparametric model of GWLR each district/city in South Sulawesi in 2017 has the value Estimator parameter for global parameters is the same value for each location, namely, a3 = 0.1724, a4 = 0.0204, and a6 = 0.0261 whereas the parameter estimator for local parameters has different values so that GWLR semiparametric model of each district/city.
, Syaripuddin Syaripuddin, Rito Goejantoro
ESTIMASI: Journal of Statistics and Its Application pp 57-70;

Exponential smoothing is forecasting method used to predict the future. Lazarus is an open source software based on free pascal compiler. at this research, program Lazarus be design used exponential smoothing method to predict electricity consumption data in Samarinda City from September to November 2018. Purposed of this researched is to determine the procedure of building an exponential smoothing forecasting application and obtained forecasting result using the built application. Procedure of built the application are designed interface, designed properties and filled coding. The optimum smoothing parameters were obtained used the golden section method. Based on the analysis, electricity consumption data in Samarinda City shows a trend pattern, then the forecasting was used double exponential smoohting (DES) method are DES Brown and DES Holt. The best forecasting method for at this researched is DES Holt, because DES Holt method produced MAPE 0,0659% less than DES Brown method produced MAPE 0,0843%.
Ika Fitriana, Erna Tri Herdiani, Georgina Maria Tinungki
ESTIMASI: Journal of Statistics and Its Application pp 80-87;

Stock is one of the popular financial market instruments. Issuing shares are one of the company's choices when deciding to fund a company. The uncertainty of stock prices in the stock market is an important event to be taken into consideration in making a decision by investors so that a model is needed to describe a stock event. GARCH Dynamic Conditional Correlation (DCC) is a model with a conditional and variance time-dependent that describes the dynamics of stock volatility. This study discusses the DCC GARCH model equation which is applied to the LQ 45 data. The model obtained for BCA shares 𝑸t = + + so it can be concluded that DCC GARCH is more appropriate for BCA shares.
, Anna Islamiyati, Raupong Raupong
ESTIMASI: Journal of Statistics and Its Application pp 71-79;

The regression approach can be carried out using three approaches namely parametric, nonparametric and semiparametric approaches. Nonparametric regression is a statistical method used to see the relationship between the response variable and the predictor variable when the shape of the data curve is unknown. Diabetes mellitus (DM) or commonly called diabetes is a disease that is found and observed in various parts of the world today. DM is often marked by a significant increase in blood sugar levels. In this study using blood sugar levels as response variables, body mass index and triglycerides as predictor variables. Data were analyzed using truncated linear spline with one, two and three point knots experiments. The best model is obtained based on the minimum generalized cross validation (GCV) value. The results obtained that the best model is linear spline using three point knots.
, Nurdiana Nurdiana, Abdul Halim
ESTIMASI: Journal of Statistics and Its Application pp 88-95;

Weaning too early can affect the growth of the baby and the mother often ignores the nutritional needs of the baby. In addition, malnutrition is more common today than during the first 4-6 months of life. This is because many families do not understand the special needs of babies and are unable to provide food with good nutritional value. The type of research used is a survey with a cross-sectional study approach. The population is all mothers who have babies aged 6 months and the sample is all mothers who have babies aged 6 months. The sampling technique was simple random sampling. The results showed that there was a significant effect between mothers who did weaning for less than 6 months with education = 0.006. There is a significant effect between mothers who do weaning for less than 6 months with employment status = 0.008. There is a significant effect between mothers who do weaning less than 6 months with birth spacing = 0.007.
, Anisa Anisa
ESTIMASI: Journal of Statistics and Its Application pp 96-104;

Crime needs to be analyzed and grouped so that the act does not cause harm either ecologically or psychologically. The statistical method that can be used to classify crime is the Average Linkage Algorithm. The study aims to group and analyze the characteristics of criminal cases in Indonesia. From the results of the analysis, 3 clusters were formed based on the average of each cluster. Cluster 1 consists of Aceh, West Sumatra, Riau, Jambi, South Sumatra, Bengkulu, Lampung, Kep. Bangka Belitung, Kep. Riau, West Java, Central Java, DI Yogyakarta, East Java, Banten, Bali, West Nusa Tenggara, East Nusa Tenggara, West Kalimantan, Central Kalimantan, South Kalimantan, East Kalimantan, North Sulawesi, Central Sulawesi, South Sulawesi, Southeast Sulawesi, Gorontalo, Maluku, North Maluku and Papua. Cluster 2 consists of North Sumatra while Cluster 3 consists of Metro Jaya. The grouping results are the basis of the government, apparatus, and the community in implementing the handling of criminal acts that occur in each cluster area so that prevention can minimize the losses caused by these crimes.
Joko Hermanianto, Dhita Sari, Nugraha Edhi Suyatma
Canrea Journal: Food Technology, Nutritions, and Culinary Journal pp 48-58;

Beef meatballs are in great demand by the public because of their non- porous texture, juicy, and chewy characteristics, as well as their ability to be stable at cooking temperatures with a long shelf life. The use of Isolated Soy Protein (ISP) shapes the character of meatballs because of its functional properties, including good water holding capacity and emulsion stability formation in a mixture of processed meat products. This research aims to technically determine the multiple emulsion properties of ISP at doses of 0%, 2%, 4%, and 8% and obtain a meatball formulation with a long shelf life that suits the target consumer. The tests include the ISP emulsification, meatball peel formation, product stability, Arrhenius shelf life method, and the sensory evaluation of the hedonic test. Subsequently, data were processed in a completely randomized 1x5 and a 4x3 factorial design using SPSS. The emulsification properties of ISP were determined by producing OE (Oil Emulsion) and PG (Purine Gel). Furthermore, ISP was discovered to change the percentage of meat consumed by approximately 2% as the characteristics of meatball products desired by consumers were achieved. The best formulation of meatballs was achieved with 2% dry ISP in the first mixing and was conducted at a boiling point of 65°C
Rachma Indriyani, Asmar Abdul Rahim, Ruzita Azmi
Hasanuddin Law Review, Volume 7, pp 89-104;

Indonesia committed to conserving the tuna resources by participating in some RFMOs. From all regional organizations where Indonesia has been joined, the CCSBT is the unique one, due to it governs a single tuna species, which is called Southern Bluefin Tuna. This kind of tuna is essential for Indonesia because it is the world’s most expensive tuna and SBT migrates through Indonesian fisheries management zones and goes even further within the territorial waters, where the SBT spawning area is located. This natural characteristic distinguishes Indonesia from other Parties to CCSBT. Nevertheless, the Country has been dealing with its obligation to comply with national quota allocation. For some fishing season periods, the CCSBT indicated Indonesia as a non-compliant. By applying the qualitative approach, this study considers how Indonesia’s non-compliance has been addressed in fishing for shared fish stocks. The data collection was conducted through semi-structured interviews and legal analysis of law and policy instruments. This method leads the elaboration to reveal domestic factors affecting non-compliance by Indonesia. This study argues, the fisheries legislation should consider the provision concerning fishing for resources under quota system, hence, it will provide sufficient legal base to take enforcement measures towards non-compliance with fishing quota.
Mazliza Mohamad, Ricco Survival Yubaidi, Safinaz Mohd Hussein, Rahmah Ismail, Suzanna Mohamed Isa, Saidatul Nadia Abdul Aziz
Hasanuddin Law Review, Volume 7, pp 61-74;

The ratio between the increased demand and limited land makes affordable housing in urban areas more difficult to accommodate. Indonesia and Malaysia, as populous countries, face problems related to housing access, especially for low-income earners in urban areas. The research was undertaken for two reasons. First, problems related to housing access for low-income earners in urban areas should be solved as soon as possible. Second, it is necessary to conduct a study in order to analyze and compare these two countries in measuring low-income earners on housing access in urban areas. To this end, the normative legal approach was applied. The materials used in this study were relevant statutes, rules, regulations, journals, articles, thesis, seminar papers, and electronic materials. The result showed that the fulfillment of housing access highly depends on the state’s developmental goals. It is also associated with principles of development that each country adheres to. The government is expected to provide accurate data in measuring low-income earners on housing access. Identification of beneficiaries by combining income classification and ability to housing access may facilitate policymakers with ease when taking affirmative measures. It is necessary to suggest initiative collaboration involving academicians, business sectors, community, and government (ABCG) in Indonesia and Malaysia to provide adequate housing in urban areas.
Andi Padauleng Meliani Anwar, Fatma Maruddin, Farida Nur Yuliati, Jamyang Tashi Wangdi, Muhammad Ihsan Andi Dagong
Canrea Journal: Food Technology, Nutritions, and Culinary Journal pp 8-16;

Kefir has a sour taste and distinctive aroma. This condition affects the level of consumer acceptance. The level of consumer acceptance of kefir can be improved by adding a sweetener, namely honey. This study aims to determine the characteristics of kefir made from commercial liquid milk to total lactic acid, pH value, viscosity, organoleptic (taste and preference) panelists to kefir with the addition of honey. This study used a completely randomized design (CRD). The treatment of this research was 4 honey concentrations (5%, 7%, 9% and without the addition of honey (0%) as a control) and was repeated 3 times. Kefir addition of honey is made in the following way: the liquid milk is sterilized at 105oC for 5 minutes and then the sterile milk is cooled down to a temperature of about 40oC. After chilling, sterile milk was inoculated with 3% (v/v) pre-propagated kefir starter and incubated at 37oC for 24 hours. Furthermore, kefir was added with honey treatment with a concentration of 5%, 7% and 9% (v/v) respectively and homogenized. Kefir honey is carried out in a series of tests including total lactic acid, acidity (pH), viscosity, organoleptic (taste and preference). The results showed that the different use of honey kefir did not change the lactic acid content. Increasing use of honey concentration causes pH value, viscosity, sweetness, and preference to increase. The best use of honey concentration in making kefir is 9%.
Mato Hang
Canrea Journal: Food Technology, Nutritions, and Culinary Journal pp 68-74;

Naniura is a traditional Batak food that is made without going through a heating process, but is made through a fermentation process using acid and salt. The use of acid and salt acts as a preservative because it can inhibit the growth of pathogenic microbes and spoilage microbes. In addition, naniura fermentation has the potential to be a growth medium for lactic acid bacteria, most of which strains can act as probiotics. However, the potential for probiotic naniura is still rarely studied and studied, so this review article is made to examine the potential for probiotic naniura and the health effects that can be obtained. The writing of this journal uses the literature study method, namely by collecting information from various scientific sources. Several studies have shown that naniura contains lactic acid bacteria that can act as broad-spectrum antimicrobials and can specifically inhibit the growth of Salmonella typhi, Bacillus cereus, Clostridium botulinum, E. coli and S. aureus. Consuming probiotic foods can have a positive effect on health, including improving the quality of the digestive tract, increasing the immune system in the body and degrading lactose so that it can be used for lactose intolerant sufferers.
Muhammad Insan Tarigan, Raisha Hafandi
Hasanuddin Law Review, Volume 7, pp 119-132;

Since the time Covid-19 was discovered in Southeast Asia, around 2.5 million people have been infected and more than 54 thousand have died by early March 2021. Even though ASEAN members have followed most of the WHO recommendations to deal with Covid-19, cases are still liable to increase. Therefore, vaccine utilization is the best chance which people believe in to fight the pandemic for now. However, the vaccine’s availability and distribution are a dilemma for the ASEAN member countries. Therefore, this article aims to determine the possibility of ASEAN’s role in creating equal access to the Covid-19 vaccine for everyone. According to the juridical normative research, ASEAN is committed to protect and promote human rights and to realize the Sustainable Development Goals (SDGs). On that basis, the organization tends to play an important role in Covid-19 vaccination in Southeast Asia by cooperating with its partners to research and create the required vaccine.
Nima Norouzi, Heshmat-Ullah Khanmohammadi, Elham Ataei
Hasanuddin Law Review, Volume 7, pp 75-88;

The Corona crisis is one of the crises that has engulfed the world and Uruguay and has marked all human beings' death and life. This crisis has many legal, political, social, and economic dimensions and has and will have different consequences in this area. So far in the last two centuries, twelve major epidemics of infectious diseases and fifteen famines, and severe droughts have engulfed our world, but this crisis is "of a different kind." It has been less critical to cover the whole world. Infect millions of people, create new words in cultures, and announce major changes in international relations, politics, law, and the world and country economies. No geographical point is safe from this, and it has a serious impact on human relations. This paper is aimed to study the Uruguayan legal system in the post-Covid-19 world. In this paper, Constitutional, Financial, commercial, Labor, Public, and judicial law is discussed in the light of the Covid-19, and its impacts and strategies to mitigate those impacts are mentioned.
Devi Dwi Siskawardani, Warkoyo Warkoyo, Jumpen Onthong
Canrea Journal: Food Technology, Nutritions, and Culinary Journal pp 1-7;

Bread is main food in several country. Sweet bread is one popular type that has a lasting sweet taste and soft textured with or without stuffing. Baking is the most important process of bread production. The temperature and time required in the baking varies according to the type of bread, big dough, and baking pan in the oven used. This research aimed to identify the optimum level of baking temperature and duration to the chemical properties of sweet bread. Randomized Complete Block Design (RCBD) Factorial with 2 factors and 3 replications were applied for this research. The first factor was baking temperature consisted 4 level (T1= 180 oC, T2= 190 oC, T3= 200 oC, T4= 210 oC), and the second factor was baking duration which composed 4 level (A1= 10 minutes, A2= 15 minutes, A3= 20 minutes, A4= 25 minutes). The results showed that there wasn’t interaction between baking temperature and duration to water content, fat, protein, and carbohydrate, but it was interaction to the ash content. The baking temperature and duration separatelly had significantly effect to the all parameter. The best result according to the SNI 01-3840-1995 was S4W4 (185 oC: 14 minutes) with water content (23.572%), fat (10.906), protein (1.105%), carbohydrate (62.940 %), and ash content (1.736 %).
Andi Nur Faidah Rahman, Victor Crystaline Muhammad, Februadi Bastian
Canrea Journal: Food Technology, Nutritions, and Culinary Journal pp 17-47;

Kepok bananas are processed bananas that have ABB genotype, the letter B indicates that banana kepok has a stronger resistance to disease and chilling injury in cold temperatures storage. Storage at cold temperatures can extend the shelf life of bananas, because cold temperatures can slow down the respiration and enzymatic processes. The purpose of this study is to observe the effect of storage temperature on quality and shelf life, and to determine optimum storage temperature. The method used is storage temperature at room, 15oC and 10oC until the banana is damaged. The parameters observed were respiration patterns, weight loss, hardness, fruit skin color, total acid, vitamin C, pH, and total soluble solids. The results showed that bananas stored at cold temperatures (10oC and 15oC) can last up to 20 days while at room temperature only lasts for 10 days. Kepok bananas stored at 10oC have not shown symptoms of chilling injury.
Dimas Pinandoyo, Asriadi Masnar, Ratih Titik Haryati, Sachin Badguja
Canrea Journal: Food Technology, Nutritions, and Culinary Journal pp 59-67;

Bir Pletok is one of traditional heritage of Betawi Culinary. Till day, Bir Pletok’s popularity is decreasing especially in young generation. This research aimed to get a new option of Bir Pletok product so that the acceptability and popularity of Bir Pletok as one of Betawi traditional culinary heritage can be preserved. Ice cream was made using mixing and freezing method. The composition for formulation was 3:1 for milk: Bir Pletok. Sensory characteristic measured with 7 levels hedonic methods. Triangle test was conducted to standardized the panelist. Panelist subjected for sensory test was semi trained panelist. Research was conducted in Politeknik Negeri Media Kreatif Art Culinary Department. Research found that overall acceptability of ice cream still medium (4.96). Respondents tend to slightly like the taste of Bir Pletok ice cream (5.47); neutrally respond to the aroma (4.67) and color (4.07), and tend to like the mouthfeel (5.53) and slightly like the after taste (5.07) of the ice cream.
Awad Ali Alanzi
Hasanuddin Law Review, Volume 7, pp 105-118;

Administrative contracts are conducted to meet government agencies' requirements in terms of procurement, which is done by tendering. The government infrastructure demand and day-to-day other needs are contracted with vendors, who render their services by applying the announced tender. Hence, the legal framework related to tendering is very important, which protects the legal rights of tender authority and vendors. This present research aims to explore the tendering law in Saudi Arabia and Egypt, having a close legal framework regarding tendering. Egypt is carrying the tender law of 1998, which is updated in 2018 recently. Moreover, tendering in Saudi Arabia depends on the Government Tenders and Procurement Law (GTPL) of 2019, which is updated from the previous version of GTPL 2006. The research explores the basic structure of the procurement system and tendering in both systems, including the discussions on procurement agency, tendering methods, basic tendering regulations, public-private partnership, transparency issue, and tendering with foreigners' bidders. Also, the recent improvements in both tendering systems are discussed. The research traces many similarities and differences in both tendering systems and suggests taking help from each other's experiences.
Drajat Indra Purnama
Jurnal Matematika, Statistika dan Komputasi, Volume 17, pp 357-369;

Smoking is a habit that is not good for health. Smoking habits are generally practiced by adults but it is possible for teenagers to do so.The Report of Southeast Asia Tobacco Control Alliance (SEATCA) entitled The Tobacco Control Atlas, ASEAN Region shows that Indonesia is the country with the highest number of smokers in ASEAN, namely 65.19 million people. This figure is equivalent to 34 percent of the total population of Indonesia in 2016. Based on these data, the authors are interested in modeling the daily cigarette consumption data for adults in Indonesia obtained from the 2015 Indonesia Family Life Survey. The variables used include the variable amount of cigarette consumption, education, level of welfare and income per month. The author wants to compare the best model that can be used to model the daily cigarette consumption of adults in Indonesia. The models being compared are Zero Inflated Poisson Regression (ZIP), Zero Inflated Negative Binomial Regression (ZINB) and Binomial Negative Hurdle Regression (HNB). The comparison results of the three models obtained that the best model is the Zero Inflated Negative Binomial (ZINB) Regression model because it has the smallest Akaike's Information Criterion (AIC) value.
Dwi Sulistiowati, Maya Sari Syahrul, Ilham Dangu Rianjaya
Jurnal Matematika, Statistika dan Komputasi, Volume 17, pp 428-437;

The Covid-19 pandemic caused the price of gold produced by PT Aneka Tambang (Antam) to experience a high increase following the world gold price, while stock investment decreased. Measuring risk is significant in financial analysis; this is related to investment funds, which are quite large and narrow about public funds. This study analyzes the risk data on Antam gold price and Antam stock closing price with an estimated Shortfall (ES). The method used to measure the risk of investing in stocks is ES. ES is the expectation of a conditional loss that exceeds Value at Risk (VaR). To compute ES data showing deviations from normality and Cornish-Fisher expansion. The volatility measurement model used is the autoregressive conditional heteroskedasticity (ARCH) and generalized ARCH (GARCH) model.This study found that the ES value of Antam gold price was smaller than Antam stock price.
Muhammad Nur -Hidayat, Jeffry Kusuma, Naimah Aris
Jurnal Matematika, Statistika dan Komputasi, Volume 17, pp 405-417;

A new two-dimensional mathematical model was developed to describe the transport phenomena of carbon dioxide in concrete structures. By treating transport phenomena as a concrete carbonation process, a two-dimensional linear partial differential equation was derived based on the principle of mass balance and convective-dispersive Equation. It was found the analytical solution by the separation of variables method combined with some substitution approaches. The numerical results are presented to illustrate the practical application of this model.
Abdul Wahab, I Nyoman Budiantara, Kartika Fitriasari
Jurnal Matematika, Statistika dan Komputasi, Volume 17, pp 438-446;

Given a nonparametric regression model Yi = g(xi) + ei, i = 1, 2, …, n, where Y is a dependent variable, x is an independent variable, g is an unknown function and e is an error assumed to be an independent, identical, and is distributed with mean 0 and variance σ2. In this research Rice estimator is used to determine the biased value of a residual variance estimator. The Rice estimator is given as follows: . The biased value of residual variance estimator of the Rice method is: , where and. Using the Rice estimator, the Tong-Wang residual variance estimator is obtained, that is: , Where , , , , , k = 1, 2, … , m. Based upon the data simulation by considering the exponential, arithmetical, and trigonometrical models, it is found that the MSE value of the Tong-Wang estimator tends to be less compared to those of the Rice estimator as well as the GSJ (Gasser, Sroka, and Jennen) estimator.
Rokhana Dwi Bekti, Yudi Setyawan, Enik Laksminiasih
Jurnal Matematika, Statistika dan Komputasi, Volume 17, pp 381-393;

The Covid-19 in Indonesia has had an impact on almost all lives, especially at economic, social, education, and health.. Efforts to prevent and reduce the number of cases are still ongoing. Likewise, research on the causes of the emergence of the Covid-19 pandemic outbreak, drugs, vaccines, and the factors that influence it are still being carried out. This study analyzes the effect of Covid-19 on inflation and the effect of population density on Covid-19 in Java. The method used is area spatial modeling. To make it easier for researchers to analyze data, this study also developed a web application based on the R shiny framework. This application has displayed valid output from the results of its use and is in accordance with existing theories, and is able to make it easier for users to carry out Covid-19 analysis in Java using the area spatial model method. The estimation results of the Spatial Durbin Model (SDM) show that the variable that has a significant effect on inflation is the inflation lag in the model with cumulative positive cases (α = 10%). This shows that the inflation of a province tends to be influenced by other neighboring provinces. Meanwhile, population density is also significant for Covid-19 positive cases (α = 5%).
Nita Anggriani, Syamsuddin Toaha, Kasbawati Kasbawati
Jurnal Matematika, Statistika dan Komputasi, Volume 17, pp 339-348;

This article examines the optimal control of a mathematical model of the spread of drug abuse. This model consists of five population classes, namely susceptible to using drugs (S), light-grade drugs (A), heavy-grade drugs (H), medicated drugs (T), and Recovery from drugs (R). The system is solved using the Pontryagin minimum principle and numerically by the forward-backward sweep method. Numerical simulations of the optimal problem show that with the implementation of anti-drug campaigns and strengthening of self-psychology through counseling, the spread of drug abuse can be eradicated more quickly. The implementation of campaigns and strengthening of self-psychology through large amounts of counseling needs to be done from the beginning then the proportion can be reduced until a certain time does not need to be given anymore. The use of control in the form of strengthening efforts to self-psychology through counseling means that it needs to be done in a longer time to prevent the spread of drug abuse.
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