Judul: . Manfaat Ekonomi Reklamasi Tambang Holcim Educational Forest Bagi Masyarakat (Studi Kasus: Desa Sekarwangi Cibadak Kabupaten Sukabumi Jawa Barat)
Abstrak: PT Holcim Indonesia Tbk telah melakukan pertambangan silika selama 35 tahun di Desa Sekarwangi Cibadak, Kabupaten Sukabumi, Jawa Barat dan melakukan reklamasi setelah tutup tambang. Holcim Educational Forest (HEF) adalah program dari reklamasi tersebut. HEF merupakan kolaborasi antara PT Holcim Indonesia Tbk dan Fakultas Kehutanan Institut Pertanian Bogor. Adanya HEF merupakan pelaksanaan kewajiban dari pemerintah dan juga menjalankan fungsi pemberdayaan masyarakat dan pendidikan. Tujuan dari penelitian ini adalah untuk mengestimasi kerugian masyarakat akibat pertambangan, mengidentifikasi langkah-langkah program HEF dan mengestimasi manfaat ekonomi. Metode penelitian ini adalah replacement cost, contingent valuation method, analisis deskriptif dan benefit transfer. Hasil penelitian ini menunjukkan rata-rata masyarakat di RW 13 dan RW 17 harus mengeluarkan Rp. 43.703,7/bulan untuk mendapatkan air bersih untuk memenuhi kebutuhan sehari-hari dan nilai total ekonomi untuk reklamasi ini adalah Rp. 729.554.543 /tahun.
Keyword: Contingent Valuation Method, Holcim Educational Forest, Reklamasi Tambang, Replacement cost

Judul: Kajian dampak reklamasi lahan tambang batubara terhadap komponen fungsi hidrologis dan ekologis DAS serta manfaat bagi masyarakat
Abstrak: This research was conducted at the PT Adaro Indonesia coal mining area in Negara watershed, sub-watershed of Barito, South Kalimantan Province. The aims of the study were: 1) to identify of the methods used for coal mined land reclamation; 2) to analyze the impacts of the reclamation on the hydrological and ecological functions of the watershed; and 3) to analyze the impact of the land reclamation activities on the involvements of and benefits for the communities. This study was carried out using survey method and field measurements in identifying the methods of reclamation. Analyzis of watershed hydrological function showed that reclamation activities significantly increased soil infiltration rate from 0.27 cm/hr to 1.01 cm/hr, decreased runoff coefficient from 49.04% to 13.97% and decreased erosion rate from 130.28 ton/ha to 7.64 ton/ha. Biodiversity analysis showed that there was no significant impact of reclamation activities on biodiversity at the early stage of reclamation trees up to 6 years of its development. However, after the reclamation trees were at the age of 15 years, the biodiversity indexes increased significantly; shurb index increased up to 1,10, seedlings 0.76, saplings 0.85, poles 0.53, and trees 0.23. Carbon sequestration analysis showed that the reclamation activities increased carbon sequestration significantly. At the area where the reclamation trees were at 15 years old the carbon stock reached 103.57 ton/ha, which consist of 95.94 ton/ha at trees, 4.12 ton/ha at undergrowth, and 3.51 ton/ha at the litter. Analysis of the impact of reclamation on social-economic of the local communities showed that the income of labor increased substantially up to Rp 36,000,000 per year, the income that have been greater than the income that can support life worthed living standard (Rp 24,000,000/year). This income was also already greather than income of South Kalimantan GDP (195%) and national GDP (117%). Multiple benefits gained by the local communities during the reclamation activities among others were the opportunities for supplier of food and housing, compost and plant seeds; the post-mining benefits from timber and non timber product of reclamation; as well as benefits from infrastructure/roads and recreation facilities.
Keyword: 

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
Keyword: