Judul: The fern diversity of South East Sulawesi
Abstrak: Floristic study has played an important role in expressing the diversity of plant species in a region. However such fern explorations are very rare, thus the data and information about ferns in Sulawesi Island particularly in South East Sulawesi is very limited. The objectives of this study is to know the diversity of fern species in South East Sulawesi region. The methods used in this study were exploration and description based on morphological characters. The study had been carried out in three locations, namely Mekongga Mountains, Uluiwoi and Wawonii Island. Materials used for this study comprised of herbarium specimens in the Herbarium Bogoriense and new specimens collected from exploration during this research in South East Sulawesi. This study documented 189 species belonging to 70 genera and 29 families. There are 173 species new collections of Pteridophyte from South East Sulawesi, 28 species of it are new from Sulawesi for Herbarium Bogoriense. Two species presumed as new species and 4 species are new records from Sulawesi. Fern in South East Sulawesi varied in their habit, rhizome, hair/scale, fronds and soral characters. Based on the habitat, there are nine types of ferns. Among three locations the greatest species diversity found in Mekongga Mountains (126 species), followed by Wawonii Island (87 species) and Uluiwoi (76 species). The degree of similarity of fern species at three different locations is low. Fern species are also used by local people for foods, medicine, ornamental plants, handycraft and construction. The identification key to the families, genera and species are provided.
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Judul: Keanekaragaman Tumbuhan Paku Terestrial di Hutan Kota DKI Jakarta
Abstrak: Urban forest is an ecosystem consisted of plant vegetation community that resembles natural forest. Trees within the urban forest form canopy that construct well-suited environment for the understory life. One of the understory is fern. Fern is a vascular and intermediate plant that produces spores as its main characteristic. This research was intended to compare the diversity of fern under three urban forests in DKI Jakarta region which were the urban forest University of Indonesia (UI), Arboretum Cibubur, and urban forest PT Jakarta Industrial Estate Pulogadung (PT JIEP) Pulogadung. The research was started in November 2011 until March 2012. Vegetation analysis was made by doing purposive sampling with square method. Fern and non-fern specimens were collected for herbarium purpose then were identified based on identification book. Light intensity, temperature, humidity, soil pH were measured and recorded as supported data. The other environment factors that measured were physical and chemical structures of soil and also the quality of the air. The coverage data and the frequency of each species were used to count the importance value index (INP). Sharon Diversity Index (H'), Evenness Index (E), and Sorenson Similarity Index (IS) were also counted in. There were epiphytes fern (4 species) and terrestrial fern (18 species) in the research urban forest. The ferns have herb habit, but they varied in the growth types which are erect; creeping and climbing. Fern leaves have variation in size, shape of fertile and sterile leaves, shape of the first leaf and so on. Based on the leaf size, two kinds of leaf, microphyl and megaphyl, were found. Based on the different shape of fertile and sterile leaves, monomorphyc and dimorphic leaves were found. The shape of monomorphyc leaf varied which were simple, pinnatus and bi-pinnatus. Fern reproductive structure in urban forest varies in the sori shape, location and composition, such as 1) sporangium is located in the leaf tips, form organ so called as strobilus; 2) longitudinal grooved sori on the edge as though covering the edge; 3) sori is located along vascular leaf between costa and the edge of the leaf; 4) sori is rounded or oval spreaded on the vascular leaf with or without indusium; 5) sori is rounded or oval, located on the tips on the free vascular near the leaf edge; 6) sori on the fertile leaflet produces sporangia that spread from the edge of the leaf to the venation tips. Sporangia on two rows is covered by indusia. The sum of terrestrial ferns found in three research urban forests were 18 species belong to 8 familia and 11 genera. In UI urban forest, it was found 10 genera with 14 species; in Arboretum Cibubur, it was found 8 genera with 11 species; but there was no fern in PT JIEP urban forest. The number of all individual ferns found in three urban forest were 1030, consisted of 334 individual in Arboretum Cibubur urban forest and 696 in UI urban forest. The species diversity index (H' = 1.97) and evenness index (E = 0.82) in Arboretum Cibubur urban forest was higher than that of
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Judul: Model Interaksi Gravitasi Banyak Massa Untuk Prediksi Dinamika Harga Bitcoin.
Abstrak: Penelitian ini ditujukan untuk memprediksi harga Bitcoin dengan menggunakan metode pengoptimuman berbasis interaksi gravitasi banyak massa (Gravitational Search Algorithm atau GSA) dengan parameter yang akurat berdasarkan nilai error yang kecil. Nilai parameter yang diperoleh dari metode GSA disubstitusi pada persamaan Gaussian untuk meramalkan harga Bitcoin selanjutnya. Hasil peramalan divalidasi dengan uji R2 dan uji MAPE. Hasil menunjukkan bahwa Model Gaussian Termodifikasi Orde 5 memberikan hasil terbaik dengan nilai R2 sebesar 0.8824 dan nilai MAPE minimal sebesar 8.4672%. Hasil simulasi dengan variasi rentang nilai parameter [0,8000], [0,800] dan [0,80] yaitu model 3 memberikan nilai R2 terbesar yaitu 0.89865, namun untuk nilai MAPE terkecil didapatkan dari simulasi dengan variasi rentang parameter [0,10000], [0,1000], dan [0,100] yaitu model 1. Hasil interpolasi, prediksi dan validasi harga Bitcoin menggunakan data harian selama 1 tahun dengan model 1 dan model 3 menunjukkan hasil yang kurang baik, ditunjukkan dengan nilai R2 yang kurang dari 0.50. Model 3 dapat dinyatakan sebagai model yang lebih baik dari model 1, dengan nilai koefesien deterministik (R2) sebesar 0.38944 dan nilai MAPE sebesar 21.21732% dibandingkan dengan model 1, dengan nilai R2 sebesar -0.43704 dan nilai MAPE sebesar 33.75404%.
Keyword: bitcoin, prediksi, GSA, gaussian