Judul: The Ability of Tree Vegetation to Reduce Surface Temperature in Serang City, Banten
Abstrak: Kota Serang merupakan pemekaran dari Kabupaten Serang berdasarkan UU No. 32/2007 yang disahkan pada tanggal 10 Agustus 2007. Berbagai fasilitas perkotaan dan pemerintahan telah dibangun untuk memenuhi kebutuhan penduduk yang tinggal di Kota Serang, sehingga terjadi peningkatan luas lahan terbangun di kota ini. Hal ini berpengaruh terhadap penurunan atau peningkatan suhu permukaan lahan. Penelitian ini bertujuan untuk menganalisis dan membandingkan pola perubahan spasial dan temporal tutupan lahan dan suhu permukaan di Kota Serang pada tahun 2016 dan 2022. Selama tahun 2016 hingga 2022, perubahan tutupan lahan terbesar terjadi pada tutupan lahan kategori vegetasi non pohon sebesar 32,28%. Sementara itu, peningkatan luas wilayah di Kota Serang dialami oleh jenis tutupan lahan berupa lahan terbangun sebesar 4.207,71 ha atau 84,62%. Kota Serang mengalami peningkatan suhu permukaan rata-rata sebesar 2,42 ?. Kelas vegetasi pohon memiliki nilai rata-rata indeks vegetasi tertinggi dan suhu permukaan terendah pada tahun 2016 dan 2022, yaitu masing-masing sebesar 0,48 dan 21,45 °C, 0,43 dan 23,11 °C., Serang City is an expansion of Serang Regency according to UU No. 32/2007, enacted on August 10, 2007. Various urban and government facilities have been built to meet the needs of the population living in Serang City, increasing built-up land area in the city, which affects the decrease or increase in land surface temperature. This study aims to analyze and compare the spatial and temporal change patterns of land cover and surface temperature in Serang City in 2016 and 2022. From 2016 to 2022, the largest land cover change occurred in the non-tree vegetation category land cover by 32.28%. Meanwhile, the built-up land in Serang City experienced an increase of 4,207.71 ha or 84.62%. Serang City experienced a 2.42 ? increase in average surface temperature. The tree vegetation class had the highest average value of vegetation index and the lowest surface temperature in 2016 and 2022, which were 0,48 and 21,45 ?, 0,43 and 23,11 ? respectively.
Keyword: Landsat 8, suhu permukaan, tutupan lahan, land cover, Landsat 8, kota serang, serang city, surface temperature

Judul: Distribusi Spasial Suhu Permukaan dan Kecukupan Ruang Terbuka Hijau di Kota Semarang
Abstrak: Semarang is one of cities that become center of public activity which is always developing in many aspects such as settlement, , roads, industries and other infrastructures. Unfortunately, The development seems to ignore environmental sustainability, in which large of green open space are converted into other land uses. The conversion will lead micro climate changes resulted in Urban Heat Island and green house effect. Those phenomenon can be observed by utilizing Geographic Information System and remote sensing. The objectives of the research are as follows : (1) land cover type identification and surface thermal of spatial distribution, , (2) the relationship between surface thermal with Green Space capacity, open land and built areas. (3) the relationship between surface thermal with Normalized Difference Vegetation Index (NDVI), through interpretation and landsat Imaginery 7 ETM. The research area situated at in Semarang City and data used were Landsat Imaginery 7ETM path/row 120/065 acquiring on April 2001 and June 2006. Landsat imagery were analyzed using an Arc View 3.2 and ERDAS Imagine 8.5 software. Surface temperature were estimated using band 6. Those analysis were aimed to identify relationship between surface thermal with Green Space, the open land, built area and NDVI. Semarang city with 38.721.70 Ha are dominated by land cover, such as built area 27.52% on year 2001 and 35,58% in 2006. The biggest land cover changes happened on built area and with advancing is 8.06%. Thermal Surface distribution were found ranges from <20 oC - ≥34 oC. The area which have thermal surface value of ≥34 oC was expanded from 16.80 % in 2001 to 25.68% in 2006. However, green space capacity areal are still covering 30%, inline with proportion based on UU. No.26 on 2007 about areal governance. The relationship between surface thermal with Green Space and other land uses were identified. It showed that surface temperature of open space area is lower than other landuses such as bare land and settlement. Moreover, It analysis result showed that surface temperature will infllence by NDVI, in which the surface temperature will increase by the lowering NDVI and vice versa.
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Judul: The Exploration of Discrete Logarithm over Finite Field GF(3m)
Abstrak: The security of many public~key algorithms is based on the problem of finding discrete logarithms. The generalized discrete logarithm problem is the following: given a finite cyclic group G of order n, a generator a of G, and an element fl E G, find the integer x, 0 ~ x ~ n - 1, such that 0: = fl. Algorithm for discrete logarithm problem focused on Menezes et al. (1997) that consist of exhaustive search algorithm, the baby-step giant-step algorithm, Pollard's rho algorithm, Pohlig-Hellman algorithm, and index-calculus algorithm. These algorithms are explorated to be used in discrete logarithm problem over finite field GF(3m ). The exploration also produces some algorithms, i.e. naif negative algorithm, baby-step mother-step algorithm, baby-step mother free-step algorithm, and baby-step free-step algorithm. All algorithms implemented using Maple 11. The Pohlig-Hellman and baby-step giant-step algorithms are efficient enough to be used in discrete logarithm problem over finite field GF(3m ) for m < 20.
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