Judul: Pemetaan Padang Lamun dengan Citra ALOS dan Citra ASTER di Pulau Pari, Kabupaten Administratif Kepulauan Seribu
Abstrak: One of the utilization of remote sensing technology is in the seagrass observations. Utilization of satellite imagery for mapping seagrass has been done before in Pari Island in 2008. Tobe able to see the changes therefore seagrass monitoring still needs to be done. The purpose of this study is to map the distribution of seagrass in Pari Island using ALOS and ASTER imagery as well as know the value of the accuracy of the seagrass distribution maps. Image processing for image sharpening using composite and Lizenga algorithm. Image classification was conducted using unsupervised classification and supervised classification. Type of seagrass found in the waters of Pari Island in general is Enhalus accoroides, Thalassia hemprichii, and Cymodocea rotundata. Extensive seagrass beds mapped with unsupervised classification method on ALOS imagery is 1.641 km2 with an accuracy of 71.01 % and the ASTER image of 1794 km2 with an accuracy of 68.11 %. Mapping the supervised classification methods known seagrass mapped area of 1.373 km2 is the ALOS images with an accuracy of 62.32 % and the ASTER image of 1.389 km2 with an accuracy of 60.87 %. Seagrass mapping with ALOS imagery has higher accuracy value of mapping using ASTER imagery.
Keyword: seagrass, classification, image, accuracy

Judul: Pemetaan Padang Lamun Menggunakan Citra Alos Avnir Dan Worldview 2 Di Pulau Pari, Kepulauan Seribu
Abstrak: Teknologi penginderaan jauh merupakan salah satu alternatif yang baik untuk memetakan lamun. Tujuan penelitian ini adalah untuk memetakan ekosistem padang lamun menggunakan dua citra dengan tingkat resolusi spasial yang berbeda. Metode yang digunakan untuk klasifikasi citra adalah metode klasifikasi tak terbimbing (unsupervised classification). Sebaran lamun pada peta hasil klasifikasi citra ALOS AVNIR banyak terdapat di sebelah barat laut Pulau Pari dan luas lamun yang didapatkan adalah sebesar 414.000 m2. Sedangkan sebaran lamun pada citra Worldview-2 terlihat menyebar diseluruh perairan dengan luas lamun sebesar 545.278 m2. Uji akurasi menggunakan confusion matrix. Nilai akurasi keseluruhan atau overall accuracy (OA) berdasarkan klasifikasi tak terbimbing menggunakan citra ALOS AVNIR adalah sebesar 56,95% sedangkan nilai OA menggunakan citra Worldview-2 sebesar 65,28%. Hasil tersebut menunjukan bahwa penggunaan citra Worldview-2 dalam memetakan padang lamun lebih baik dibanding menggunakan citra ALOS AVNIR
Keyword: lamun, ALOS AVNIR, Worldview-2, confussion matrix, Pulau Pari

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model