Judul: Modeling Human Movement in the Spread of Covid-19 Using the Modified Graph PageRank Algorithm (Case Study: East Java Province)
Abstrak: Covid-19 merupakan penyakit menular yang disebabkan oleh SARS-CoV-2. Pada 1 Mei 2021, Provinsi Jawa Timur merupakan salah satu provinsi dengan tingkat penyebaran dan kematian Covid-19 paling tinggi di Indonesia. Penelitian ini akan memodelkan pergerakan manusia dalam kaitannya dengan penyebaran Covid-19 di Provinsi Jawa Timur dengan menggunakan 22 variabel demografi, sosial, dan ekonomi untuk menggambarkan aktivitas manusia dan karakteristik wilayah. Algoritme Modifikasi Graph PageRank akan menghitung nilai PageRank untuk setiap variabel dengan nilai koefisien yang menunjukkan besaran pengaruh dari masing-masing variabel (dilambangkan dengan β). Penelitian ini menunjukkan bahwa variabel produk domestik regional bruto, jumlah penduduk laki-laki, tingkat pengangguran, jumlah kejahatan, kepadatan penduduk, dan angka melek huruf memberikan pengaruh terhadap pergerakan manusia dalam kaitannya dengan penyebaran Covid-19 di Provinsi Jawa Timur dengan nilai koefisien korelasi sebesar 0,867., Covid-19 is an infectious disease caused by SARS-CoV-2. As of May 1st, 2021, East Java Province is one of the provinces with the highest spread and mortality rates of Covid-19 in Indonesia. This study will model human movement in the spread of the Covid-19 in East Java Province by using 22 demographic, social, and economic variables to describe human activities and regional characteristics. The Modified Graph PageRank Algorithm will calculate the PageRank score for each variable with a coefficient value that indicates the magnitude of the influence of each variable (denoted as β). This study shows that gross regional domestic product, male population, unemployment rate, crime rate, population density, and literacy rate variables have an influence on human movement in the spread of Covid-19 in East Java Province with a correlation coefficient of 0.867.
Keyword: Covid-19, East Java, Human Movement, Modified Graph PageRank

Judul: Modeling Human Mobility by Train on the Spread of COVID-19 Using Distance-Decay PageRank Algorithm
Abstrak: Sejak awal tahun 2020, dunia sedang dilanda wabah penyakit menular COVID-19. Pada 9 April 2021, telah tercatat 1,552,880 jiwa yang terinfeksi penyakit ini di Indonesia. Seseorang yang telah terinfeksi COVID-19, berpotensi untuk menularkan virus tersebut kepada orang lain. Penelitian ini bertujuan untuk memodelkan pergerakan manusia menggunakan transportasi kereta api pada sebuah jaringan spasial yang dibentuk berdasarkan stasiun kereta api serta sebaran perjalanan kereta di Provinsi Jawa Timur. Hal ini dilakukan agar dapat menganalisis kaitan antara pergerakan manusia menggunakan transportasi kereta api terhadap penyeabaran penyakit COVID- 19. Model dibuat menggunakan algoritme Distance-decay PageRank. Penelitian ini telah memodelkan pergerakan manusia menggunakan transportasi kereta api di Provinsi Jawa Timur serta menunjukkan bahwa hubungan antara pergerakan manusia menggunakan transportasi kereta api terhadap penyebaran COVID-19 di Provinsi Jawa Timur berkorelasi tinggi dengan nilai koefisien korelasi sebesar 0,7 (r = 0,7)., Since early 2020, the world is dealing with the COVID-19 outbreak. In Indonesia, up to April 9th, 2021, people infected with the disease are about 1,552,880. A person who has been infected with COVID-19 has the potential to transmit the virus to others. This study aims to model human mobility by train using spatial network in East Java Province. This research examines the relationship between human mobility by train to the spread of the COVID-19 disease in East Java Province. The spatial network is formed based on train stations and train trips, and the model was created using the Distance-decay PageRank algorithm. This research has modeled human mobility using the train in East Java Province. It shows that human mobility using the train is highly correlated with the spread of COVID-19 in East Java Province, with correlation coefficient is 0.7 (r = 0.7).
Keyword: Modeling human mobilty, COVID-19, Distance-Decay PageRank, Spatial network, East Java

Judul: Sintesis dan Pencirian Natrium Titanat (Na2Ti2O4(OH)2) Berbahan Dasar Titanium Dioksida
Abstrak: TiO2 can be utilized as basic material for synthesis of sodium titanate (Na2Ti2O4(OH)2). This research was purposed to synthesize and characterize sodium titanate from TiO2 rutile powder as a basic material. Sodium titanate was synthesized by hydrothermal process at temperature 130 °C by mixing TiO2 rutile powder with 5 M and 10 M NaOH solution, then each was calcinated at temperature 700 °C. The energy dispersive X-ray analysis showed that sodium titanate has been successfully synthesized. This result was also supported by functional group analysis with Fourier transform infrared (FTIR) spectrofotometer showing the existence of Ti-O-Na vibration band at 989.42 cm-1. The formation of sodium titanate was depend on the reaction condition such as temperature, reaction time, and NaOH concentration. Scanning electron microscope image indicated that sodium titanate synthesized at 130 °C in 20 hours reaction time with 10 M NaOH had crystal size of 99.37 nm.
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