Judul: Eksternalitas Pertambangan Emas Rakyat Di Kabupaten Buru Maluku
Abstrak: Pertambangan emas di Kabupaten Buru dimulai tahun 2012, dengan ditemukan emas pada akhir tahun 2011di lokasi “Gunung Botak” atau biasa disebut masyarakat adat dengan nama “Leabumi”. Pertambangan ini diatur oleh Pemerintah adat Dataran Waeapo petuanan Kayeli yang diatur oleh Raja (Kepala Desa) Kayeli dan Hinolong Baman (kewang/penjaga dataran tinggi) serta marga-marga yang mempunyai hak atas wilayah Leabumi. Karena pertambangan yang ada tidak ada campur tangan pemerintah maka pertambangan ini termasuk pertambangan tanpa izin usaha (PETI) atau illegal. Permasalahan umum yang terjadi di Kabupaten Buru dengan adanya dampak pertambangan rakyat terhadap kehidupan masyarakat dan perubahan kualitas lingkungan yaitu pencemaran Merkuri. Tujuan penelitian yaitu : 1) mengetahui persepsi masyarakat terhadap keberadaan pertambangan. 2) mengidentifikasi kerusakan air tanah yang diakibatkan dari pertambangan. 3) mengestimasi nilai perubahan produksi perikanan akibat pertambangan. 4) mengidentifikasi dan menghitung biaya transaksi dari pertambangan emas rakyat liar. 5) mengidentifikasi dan menghitung WTP biaya transaksi dan WTP perbaikan kualitas lingkungan. 6) mengidentifikasi nilai eksternalitas dari kegiatan pertambangan emas rakyat liar. Metode analisis yang digunakan yaitu analisis pendekatan statistik, uji laboratorium untuk kualitas air, analisis nilai perubahan produksi perikanan, analisis willingness to pay dengan model contingent valuation method (CVM), analisis regresi linier dan analisis logistic regression. Hasil dari penelitian ini adalah : 1) Persepsi masyarakat terhadap keberadaan pertambangan emas illegal ini 20 responden memilih ditutup dan 24 responden memilih dibuka. Responden yang merasakan akan adanya bahaya lingkungan yang juga berpengaruh terhadap usahanya akan memilih ditutup, sedangkan responden yang merasakan dampak positif dari pertambangan terhadap pendapatan akan memilih dibuka. 2) Pertambangan emas rakyat di Kabupaten Buru menimbulkan eksternalitas positif dan negatif. Penurunan kualitas lingkungan dalam hal ini air sungai maupun air tanah di Kabupaten Buru belum terdeteksi adanya Merkuri namun bukan berarti tidak terjadi pencemaran Merkuri, karena Merkuri yang ada masih sangat kecil. 3) Akibat adanya pertambangan produksi perikanan mengalami penurunan produksi pada tahun 2012 sebesar 1.560,2 ton. 4) Biaya masuk pertambangan diatur oleh Pemerintah Adat Dataran Kayeli. Biaya masuk untuk penambang laki-laki sebesar Rp.750.000/orang/tiga bulan, untuk penambang wanita sebesar Rp.500.000/orang/tiga bulan 5) Kesediaan membayar untuk perbaikan kualitas lingkungan sebesar Rp.430.000/orang/bulan. 6) Total kerugian pemerintah daerah terhadap pungutan biaya masuk pertambangan emas rakyat ini adalah sebesar Rp.131.187.700.000/ tahun, dan total kerugian dari penurunan produksi perikanan adalah sebesar Rp.1.214.227.000. .
Keyword: Eksternalitas pertambangan, willingness to pay, produksi perikanan, dampak ekonomi

Judul: Valuasi Ekonomi Kegiatan Pertambangan Emas dan Persepsi Masyarakat Terhadap Dampak Sosial di Kecamatan Huta Bargot, Sumatera Utara
Abstrak: Mandailing Natal is one of the regencies in North Sumatra which is rich in natural resources. The natural resource which has been managed is gold mining. Huta Bargot is one of the sub-districts in the regency where there is Illegal Gold Mining (PETI). The existence of this illegal gold mining has socio-economic impact on the people involved in the mining activities either directly or indirectly, which can be positive or negative. This study aimed to analyze the economic impact through economic valuation with cost-benefit analysis, people’s perceptions of social changes due to the gold mining, and the form of community wisdom on the utilization of natural resources. This study used secondary data and primary data. The secondary data was obtained from written documents either in the form of scientific papers or official documents from the relevant authorities. The primary data was obtained from direct observation at the study site and through interviews (in-depth and structured). The determination of the respondents in the study used purposive sampling method, which was based on the research need appropriate to the research objectives. The respondents included 30 miners and 30 non-miners, with 9 key persons consisting of 3 religious leaders, 3 adat leaders and 3 village heads. The data analysis of economic valuation used Net Present Value (NPV) and Benefit Cost Ratio (BCR) with a period of 20 years and an interest rate of 8%. The data analysis of the people’s perceptions used perception index. The data analysis of local wisdom was conducted descriptively. The cost analysis obtained from mining costs due to the forest degradation (as producer firewood, animals, medicinal plants, erosion-flood control) amounted to Rp. 1 966 086 740 per year. The cost of water resource reduction (water availability and fish production) was Rp 275,676,000 per year. The cost of ladang production decline was Rp. 530 596 800 per year. The cost of people’s health deterioration amounted to Rp. 19 936 000 per year. The benefit value derived from the increase in revenues was Rp. 128 679 996 per year. Based on the costbenefit analysis, the NPV obtained was Rp. -21 606 438 873 and the BCR was 0.055. The NPV indicated that the land conversion—from the forest land to the mine land—resulted in a loss of Rp. -21 606 438 873, so that the people’s gold mining was not feasible to continue. The BCR showed that every Rp 1 000 spent by the people only brought benefit to a group of people from mining activities amounting to Rp 55. Social changes had occurred in the form of increased crime, social jealousy and an increasingly consumptive community.There was a perception gap between miners and non-miners on the social impacts in terms of increased crime, social jealousy, an increasingly consumptive community, and those who should rehabilitate the post-mining land. The people were concerned about the impacts which would continue to increase due to the absence of land rehabilitation. According to the local wisdom in Bargot Huta, people should utilize the natural resources wisely and they must have the awareness of maintaining the quantity and quality
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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