Judul: Financial Feasibility of Glagah Wangi Istambul Mangrove Ecotourism after Rehabilitation in Tambakbulusan, Demak Central Java
Abstrak: Rehabilitasi hutan mangrove akibat abrasi pantai dan konversi lahan di Desa Tambakbulusan telah dilakukan. Untuk mencegah rusaknya hutan mangrove hasil rehabilitasi tersebut perlu dikembangkan pemanfaatan mangrove pasca rehabilitasi yang lebih ramah lingkungan, salah satunya dengan mengembangkan usaha Ekowisata Mangrove Glagah Wangi Istambul, yang dikelola oleh Badan Usaha Milik Desa (BUMDes) Istambul Karya. Penelitian ini bertujuan untuk mengetahui kondisi ekosistem mangrove pasca rehabilitasi, mengetahui estimasi jumlah pengunjung, mengetahui kelayakan finansial, dan mengetahui sensitivitas usaha. Analisis yang digunakan yaitu analisis deskriptif kuantitatif, peramalan jumlah pengunjung, analisis biaya dan manfaat, analisis aliran kas, dan analisis nilai pengganti. Hasil peramalan jumlah pengunjung bulan Oktober 2020-November 2023 menunjukkan tren multiplikatif dengan kecenderungan meningkat. Hasil analisis kelayakan finansial menunjukkan ekowisata ini layak diusahakan dan mendatangkan keuntungan pada tingkat diskonto bulanan 1,16%. Tingkat kepekaan maksimum terhadap kenaikan biaya sebesar 209,3%, dan pada penurunan pendapatan sebesar 8,70%., Rehabilitation of mangrove forests due to coastal abrasion and land conversion in Tambakbulusan Village has been carried out. To prevent the destruction of the rehabilitated mangrove forest, it is necessary to develop a more environmentally friendly post-rehabilitation mangrove utilization, one of which is by developing the Glagah Wangi Istambul Mangrove Ecotourism business, which is managed by the Village-Owned Enterprises (BUMDes) Istambul Karya. This study aims to determine the condition of the post rehabilitation mangrove ecosystem, estimated the number of visitors, financial feasibility, and business sensitivity of Glagah Wangi Istambul Mangrove Ecotourism. The research using quantitative descriptive analysis, forecasting the number of visitors, cost and benefit analysis, cash flow analysis, and switching value analysis. Forecasting the number of visitors in October 2020-November 2023 show a multiplicative trend with an increasing trend. The results of the financial feasibility analysis show that business is feasible and profitable at monthly discount of 1.16%. The maximum level of sensitivity to the increase in costs is 209,3%, and to a decrease in income is 8,70%.
Keyword: Ecotourism, Financial feasibility, Forecasting, Glagah Wangi Istambul Mangrove, Rehabilitation, Switching value analysis

Judul: Economic Assessment and Sustainability of  Post Rehabilitation Mangrove Forest Ecosystem in Karangsong Village, Indramayu  District
Abstrak: Kerusakan ekosistem hutan mangrove di Desa Karangsong didominasi oleh konversi lahan mangrove menjadi areal tambak yang berdampak pada berkurangnya luas hutan mangrove dan hilangnya fungsi dan manfaat dari ekosistem hutan mangrove tersebut. Kerusakan ini membuat masyarakat menyadari pentingnya menjaga kelestarian ekosistem hutan mangrove dan mulai melakukan upaya pemulihan kembali ekosistem hutan mangrove melalui kegiatan rehabilitasi mangrove dari tahun 2008 sampai 2016. Penelitian ini bertujuan untuk (1) mengestimasi nilai ekonomi total dari ekosistem mangrove pasca rehabilitasi di Desa Karangsong, dan (2) menganalisis status keberlanjutan ekosistem mangrove pasca rehabilitasi di Desa Karangsong. Metode pada penelitian ini menggunakan valuasi ekonomi dan Multidimensional Scaling (MDS) dengan alat analisis Rap_Mforest Hasil estimasi nilai ekonomi total ekosistem hutan mangrove Karangsong yaitu sebesar Rp. 39.554.620.325 per tahun. Status keberlanjutan ekosistem hutan mangrove Karangsong memiliki cukup berkelanjutan (64,43)., The destruction mangrove forest ecosystem in Karangsong Village was dominated by the conversion of mangrove area into pond areas, those situation has an impact on the reduction of mangrove forest area and the loss of environmental services of the ecosystem. Furthermore, the community realize the importance of preserving mangrove forest ecosystem and began to restore mangrove forest ecosystem through mangrove rehabilitation activities from 2008 to 2016. This study aims to: (1) estimate the total economic value of the post-rehabilitation mangrove ecosystem in Karangsong Village, and (2) analyze the sustainability status of the post-rehabilitation mangrove ecosystem in Karangsong Village. The method in this study uses economic valuation and Multidimensional Scaling (MDS) with the Rapfish analysis tool. The estimation result of the total economic value of the Karangsong mangrove forest ecosystem is IDR 39.554.620 per year. The sustainability status of the Karangsong mangrove forest ecosystem is moderately sustainable (64.43).
Keyword: Economic valuation, damage to mangrove ecosystems, multidimensional scaling, Rap_Mforest

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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