Judul: Analysis of Urban Heat Island Phenomenon in Bogor City Using Cloud Computing Technology
Abstrak: Fenomena Urban Heat Island (UHI) merupakan fenomena yang biasa terjadi di kota-kota besar karena tingginya kepadatan lahan terbangun. UHI dapat diidentifikasi menggunakan data citra satelit menggunakan teknik penginderaan jauh. Seiring berjalannya waktu, teknik penginderaan jauh dapat dilakukan melalui internet tanpa perlu mengunduh data terlebih dahulu dengan menggunakan teknologi cloud computing atau komputasi awan. Penelitian ini menggunakan Google Earth Engine sebagai platform komputasi awan untuk keperluan analisis data citra satelit. Data yang digunakan adalah Landsat 8 OLI/TIRS path 112 row 64 & 65 dan peta batas administrasi Kota Bogor. Penelitian ini mengidentifikasi fenomena UHI dengan mengestimasi suhu permukaan dan suhu udara, mengestimasi indeks spektral, dan mengestimasi Urban Thermal Field Variance Index (UTFVI). Hasil yang diperoleh menunjukkan bahwa sebaran suhu di Kota Bogor memiliki nilai yang tinggi di pusat Kota Bogor tepatnya di Kecamatan Bogor Tengah. Hal ini diperkuat dengan hasil UTFVI dimana Kecamatan Bogor Tengah memiliki nilai indeks terburuk. Kedua hasil ini dapat menggambarkan fenomena UHI di Kota Bogor. Nilai indeks spektral Normalized Difference Built-up Index (NDBI) memiliki pengaruh signifikan terhadap nilai suhu permukaan di Kota Bogor dengan nilai koefisien determinasi yang diperoleh adalah 0,769, 0,725, dan 0,782. NDBI dapat dijadikan acuan atau indikator fenomena UHI., The Urban Heat Island (UHI) phenomenon is a common phenomenon in big cities due to high density of built-up area. UHI can be identified using satellite image data with remote sensing techniques. As time goes by, remote sensing techniques can be done via internet without downloading the data first by using cloud computing technology. This study uses Google Earth Engine as a cloud computing platform for analyzing satellite image data. The data used are Landsat 8 OLI/TIRS path 112 row 64 & 65 and administrative boundary map of Bogor City. This study identified UHI phenomena by estimating the surface temperature and air temperature, estimating the spectral indices, and estimating Urban Thermal Field Variance Index (UTFVI). The results show that the temperature distribution in Bogor City has a high value in the center of Bogor City, precisely in Central Bogor District. This is reinforced by the UTFVI results where Central Bogor District has the worst index value. These two results can describe the UHI phenomenon in Bogor City. The Normalized Difference Built-up Index (NDBI) value has a significant effect on the surface temperature value in Bogor City. The coefficient of determination values obtained are 0.769, 0.725, and 0.782. NDBI can be used as a reference or indicator of the UHI phenomenon.
Keyword: Google Earth Engine, land surface temperature, spectral indices, surface energy balance

Judul: Distribusi Spasial dan Temporal Urban Heat Island Wilayah Bogor
Abstrak: The activities which is centered in the urban or industrial areas form a typical microclimate characteristic that is the urban heat island. In general, UHI refers to increase of the air temperature, but it can also refer to the relative heat surface or sub-surface material that have a higher temperature than the temperature surround it. In this study analysis is conducted by using remote sensing data that has advantages in the provision of spatial data with a wide coverage area. The determination of spatial and temporal distributions of UHI Bogor region use Terra MODIS L1B raster image data with channel 31 and channel 32 through extraction surface temperature components. The raster image uses two raster image data (day and night) in a month of July in the year 2000 until 2011. The results of this study indicate that Bogor area at the day time have an average surface temperature of 26.8 °C, while at the night time an average surface temperature of 19.4 oC. During the day time, the surface temperature forms the urban heat island pattern which centered in the city of Bogor. While at the night time, the surface temperature tends to form an increasing surface temperature gradient towards to the city of Depok until to the city of Jakarta. At the day time, the city of Bogor gives the intensity of UHI greater than at night time. During the daytime the intensity of UHI which are concentrated in the city of Bogor has an average value of 2.1 °C at the distance of 7 km and 3.6 °C at the distance of 14 km. While at the night time the intensity of UHI has an average value of 0.3 °C at the distance of 7 km and 1.2 °C at the distance of 14 km.
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Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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