Judul: Benthic Community in Mesophotic Coral Ecosystems (MCEs) North Lombok Strait
Abstrak: Ekosistem terumbu karang mengalami kerusakan akibat peningkatan suhu dan kegiatan manusia (antropogenik) seperti pariwisata dan perikanan tangkap. Fenomena tersebut biasa ditemukan pada perairan 5 - 18 meter. Teridentifikasi terdapat kehidupan ekosistem terumbu karang berada di kedalaman lebih dari 30 meter atau zona mesofotik yang tidak terpengaruh terhadap tekanan lingkungan pesisir. Penelitian ini bertujuan untuk mengetahui sebaran komposisi komunitas bentik serta persentase tutupannya di ekosistem terumbu karang mesofotik (MCEs) di perairan Selat Lombok Utara dengan metode Underwater Photo Transect (UPT). Penelitian dilaksanakan pada tanggal 3 – 5 September 2020 di 3 stasiun dengan kedalaman 10 - 50 meter. Kondisi ekosistem terumbu karang di Perairan Selat Lombok pada kedalaman 10 hingga 20 m di setiap stasiun mengalami kerusakan akibat tekanan sehingga presentasi tutupan abiotic dan dead coral with algae tinggi. Puncak persentase tutupan hard coral di setiap stasiun berada di kedalaman 30 hingga 40 m. Semakin bertambahnya kedalaman komunitas bentik dengan kategori sponge, soft coral, dan other fauna semakin meningkat persentase tutupannya., Coral reef ecosystem are damaged due to the impact of rising sea surface temperature and anthropogenic activities such as tourism and fishing activities. This phenomenon is usually found in waters with a depth of 5–18 meters. It was identified there is life in the coral reef ecosystem at a depth more than 30 meters (mesophotic zone) which is not affected by the anthropogenic activities. This study was conducted to determine the distribution of benthic community composition and percentage cover in Mesophotic Coral Ecosystems (MCEs) in North Lombok Strait using Underwater Photo Transect (UPT) method. The study was conducted from 3- 5 September 2020 at 3 stations with depths of 10 - 50 meters. The condition of the MCEs in the depth of 10 to 20 m at each station was damaged due to many factors that influenced it, resulting in a high percentage of abiotic and dead coral with algae cover at that location. The highest percentage of hard coral cover was at each station with a depth of 30 to 40 m. As the depth increases, the percentage of benthic community cover also increases with the categories of sponge, soft coral, and other fauna.
Keyword: North Lombok Strait, Benthic Community, Mesophotic, Depth

Judul: Benthic and Nektonic Complexity in Kei Besar Coral Reef Ecosystem, Southeast Maluku
Abstrak: Penelitian ini dilakukan untuk menentukan kondisi ekosistem terumbu karang di perairan Kei Besar, dengan mengukur komposisi dan kompleksitas habitat terumbu karang terhadap kelimpahan dan keanekaragaman spesies ikan terumbu. Penelitian dilakukan dengan pengamatan bawah air menggunakan Point Intercept Transect (PIT), Belt Transect dan estimasi visual kompleksitas struktural habitat di sembilan titik pengamatan pesisir timur Kei Besar. Hasil menunjukkan persen tutupan karang yang tinggi (hingga 75%) dan kemungkinan yang rendah untuk terjadi pergeseran dominansi ke tutupan organisme bentik lain seperti alga, karang lunak, atau spons. Tidak diperoleh hubungan yang spesifik (multikorelasi) antara kekayaan jenis dan kelimpahan ikan dengan sejumlah variabel komunitas bentik terumbu, terutama tutupan karang keras hidup dan kekayaan genus karang. Satu-satunya variabel bentik yang didapati berpengaruh positif terhadap komunitas ikan adalah kompleksitas habitat dasar terumbu karang., This research was conducted to determine the condition of coral reef ecosystems in Kei Besar, by measuring the composition and complexity of coral reef habitats, abundance and diversity of reef fish species. It was carried out using underwater observation using Point Intercept Transect (PIT), Belt Transect and visual estimation of the structural complexity of the habitat at nine observation points along the eastern coast of Kei Besar. The results showed a high percentage of coral cover (up to 75%) and low probability of a shift in dominance of other benthic organisms such as algae, soft corals, or sponges. No specific relationship (multicorrelation) was found between species richness and fish abundance with a number of reef benthic community variables, especially live hard coral cover and coral genera richness. The only benthic variable that was found to have a positive effect on the fish community was the complexity of the coral reef base habitat.
Keyword: organisme bentik, ikan terumbu, kompleksitas habitat, komunitas, ekosistem terumbu karang, benthic organism, reef fish, habitat complexity, communities, coral reef ecosystem

Judul: Pemodelan Harga Saham Menggunakan Generalisasi Proses Wiener dan Model ARIMA
Abstrak: The capital stock of a business entity represents the original capital paid or invested in the business by its founders. Since it is known that the stock price fluctuates in time, it is necessary to have a model to forecast the stock price in the future. In this study, stock price is assumed to follow a continous stochastic process. One of stochastic models that can be used to model the stock price is a model of generalized Wiener process. This model describes the time evolution of stock price as a stochastic variable with constant drift and variance rate. On the other hand, since stock prices data are time series data, so ARIMA model can also be used to model this phenomena and to predict the stock price in the future. Both models are estimated using a chosen set of data. The result is then used to forecast the stock price in the future time. It can be concluded that forecasting study using generalized Wiener process shows a slightly better result than the ARIMA model.
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