Judul: Mapping the Extent and Density of Mangroves Using Sentinel 2A Image Classification in CMC Tiga Warna
Abstrak: Mangrove adalah tumbuhan pantai yang tumbuh di daerah pasang surut dan pantai berlumpur. Berfungsi sebagai zona penyangga dan melindungi garis pantai dari kerusakan akibat abrasi. Teknologi penginderaan jauh sangat tepat digunakan untuk pemantauan ekosistem mangrove di CMC Tiga Warna yang mengalami peningkatan belakangan ini. Tujuan dari penelitian ini adalah untuk mengetahui perubahan luasan dan kerapatan mangrove menggunakan Citra Sentinel-2A. Klasifikasi kerapatan citra menggunakan metode Normalized Difference Vegetation Index (NDVI) dan dilakukan pengambilan data lapang sebanyak 55 titik menggunakan metode Hemispherical photography. Hasil penelitian menunjukkan 3 kelas kerapatan mangrove yaitu kelas rapat dengan luasan sebesar 46,10 ha, kelas sedang 0,75 ha, dan kelas jarang 0,82 ha pada tahun 2015. Tahun 2023 luas mangrove untuk kelas rapat, sedang dan jarang masing-masing adalah 62,27 ha, 1,01 ha, dan 0,59 ha. Luas total hutan mangrove tahun 2015 sebesar 47,67 ha dan tahun 2023 sebesar 63,87 ha. Kerapatan mangrove di CMC Tiga Warna mengalami peningkatan selama 8 tahun terakhir pada kelas rapat dan sedang. Hal ini mengindikasikan program pengelolaan mangrove di lokasi ini dapat dikatakan berhasil., Mangroves are coastal plants that grow in tidal and muddy areas. They function as buffer zones and protect coastlines from abrasion damage. Remote sensing technology is highly suitable for monitoring the mangrove ecosystem in CMC Tiga Warna, which has experienced recent growth. The objective of this study is to determine changes in the extent and density of mangroves using Sentinel-2A imagery. The classification of density was conducted using the Normalized Difference Vegetation Index (NDVI) method, and field data collection is conducted at 55 points using the Hemispherical Photography. The research results show that there are 3 density classes of mangroves, namely dense class with an area of 46.10 ha, moderate class 0.75 ha, and sparse class 0.82 ha in 2015. In 2023, the area of mangroves for dense, moderate, and sparse classes respectively are 62.27 ha, 1.01 ha, and 0.59 ha. The total area of mangrove density in 2015 was 47.67 ha, while in 2023 it reached 63.87 ha. The mangrove density in CMC Tiga Warna has increased by 16.2 ha over the past 8 years for the dense and moderate classes. It indicates that the development program of mangrove in this location can be considered successful.
Keyword: CMC Tiga Warna, Kerapatan, Mangrove, NDVI, Sentinel 2A Satelit

Judul: Mangrove Distribution and Density Analysis  Using Sentinel-2A Imagery at Bandar Bakau Dumai
Abstrak: Mangrove merupakan tumbuhan yang hidup di daerah pesisir pantai yang berfungsi sebagai habitat biota laut, dan melindungi garis pantai. Penelitian ini bertujuan memetakan sebaran, luasan, dan kerapatan mangrove di Bandar Bakau Dumai pada tahun 2022 menggunakan citra Sentinel-2A. Data lapang yang dibutuhkan yaitu foto tutupan kanopi dan titik koordinat pengambilan data. Perhitungan persentase tutupan mangrove dihitung menggunakan metode hemispherical photography. Indeks vegetasi dari citra satelit dihitung menggunakan algoritma NDVI. Uji akurasi klasifikasi citra menggunakan metode MLH. Terdapat 10 jenis mangrove yang ditemukan di wilayah penelitian dan didominasi oleh Rhizophora apiculate dan Xylocarpus granatum. Nilai tutupan kanopi mangrove hasil pengamatan berkisar antara 89,2% hingga 31,14%. Nilai indeks vegetasi dilokasi kajian pada tahun 2022 dengan metode NDVI berkisar pada -0,195 hingga 0,775. Luas sebaran mangrove di Bandar Bakau Dumai pada tahun 2022 sebesar 35,52 ha dengan dua tipe kerapatan yaitu mangrove rapat dan mangrove sedang. Hasil uji akurasi klasifikasi citra sebesar 81,63%. Hasil koefisien korelasi antara tutupan kanopi dan NDVI sebesar 75% tergolong korelasi tinggi. Penelitian ini menunjukkan nilai NDVI dapat menjadi acuan nilai tutupan kanopi mangrove., Mangroves are plants that live in coastal areas that function as a habitat for marine life and protect the coastline. This studied aim to map the distribution, area, and density of mangroves in Dumai Bakau Airport in 2022 using Sentinel-2A imagery. The required field data were photos of canopy cover and coordinate points for data collection. Mangrove cover percentage was calculated using the hemispherical photography method. Vegetation index from satellite imagery was calculated using NDVI algorithm. Image classification accuracy test was using MLH method. There were 10 mangrove species found in the study area and were dominated by Rhizophora apiculate and Xylocarpus granatum. The observed mangrove canopy cover value ranged from 89.2% to 31.14%. The vegetation index valued at the study location in 2022 using the NDVI method ranges from -0.195 to 0.775. The distribution area of mangroves in Dumai Bakau Airport in 2022 was 35.52 ha with two types of density, namely very dense and dense mangroves. The result of image classification accuracy test was 81.63%. Correlation coefficient between canopy cover and NDVI of 75% was classified as high correlation. This studied show that the NDVI value can be used as a reference for the mangrove canopy cover value.
Keyword: Bandar Bakau Dumai, Mangrove, Sentinel-2A, NDVI

Judul: The Dynamic of HIV Virus Infection as a Result of Protease Inhibitor Therapy.
Abstrak: Acquired immunodeficiency syndrome (AIDS) is defined as symptoms of deterioration human immune system caused by human immunodeficiency virus (HIV). The virus damages the leucocytes; therefore, once a person infected by the HIV, his/her immune system will be paralyzed and eventually will not be able to survive from any disease. HIV is transmitted in many ways, such as having unsafe sex, using unsterilized syringe, blood transfusion, and many more. So far, there has not been discovered yet a way or a medicine that can totally cure this disease. However, reverse transcriptase inhibitor therapy, protease inhibitor, or combination of those two can decline the growth of virus inside the body of the infected person. Therefore, the immune system will be enhanced back to normal phase. In this paper, will analyze the effect of protease inhibitor therapy on the dynamics of virus inside the blood with different value of effectiveness. There are two mathematical models of protease inhibitor therapy to consider, i.e. perfect and imperfect protease inhibitor. The perfect protease inhibitor therapy hinders the virus to grow well and not to infect healthy leucocytes. On the other hand, the imperfect one cannot completely detained the virus growth.
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