Judul: The Contribution of Ecotourism of Petengoran Mangrove Forest to the Income of the Gebang Village Community
Abstrak: Berbagai tipe hutan memiliki potensinya masing-masing seperti halnya hutan mangrove yang berpotensi menjadi ekowisata guna memberikan manfaat ekonomi bagi masyarakat sekitar. Penelitian ini bertujuan menganalisis kontribusi Ekowisata Hutan Mangrove Petengoran terhadap pendapatan masyarakat, menganalisis persepsi pengunjung ekowisata serta mengidentifikasi tingkat kesejahteraan rumah tangga masyarakat pengelola ekowisata. Pengumpulan data dilakukan dengan wawancara terhadap 28 responden masyarakat yang menjadi pengelola ekowisata dan 30 pengunjung ekowisata serta studi pustaka. Hasil penelitian menunjukkan kontribusi ekowisata terhadap pendapatan total rata-rata rumah tangga masyarakat sebesar 32,04%, mayoritas pengunjung merasa puas dengan fasilitas, pengelolaan dan harga tiket masuk ekowisata dan kesejahteraan masyarakat pengelola berada pada tingkat cukup hidup layak., Various types of forests have their own potential, such as mangrove forests which have the potential to become ecotourism in order to provide economic benefits for the surrounding community. Data were collected by interviews to 28 respondents which are ecotourism management communities and 30 visitors as well as literature study. The results showed that the contribution of ecotourism to the average total income of the community's household was 32.04%, and the majority of visitors were satisfied with the facilities, management, and ticket prices for ecotourism and the welfare of the managing community was at a decent level of living.
Keyword: Kontribusi, Kesejahteraan, Hutan Mangrove, Ekowisata

Judul: Kontribusi Pengelolaan Hutan Rakyat Terhadap Pendapatan Rumah Tangga Petani dan Analisis Kelayakan Usaha Hutan Rakyat. (Studi di Desa Babakanreuma, Kecamatan Sindangagung, Kabupaten Kuningan, Propinsi Jawa Barat)
Abstrak: According to Hardjanto (2000), income of community forest farmers in Java are still positioned as a by product and incidental. Range of income is not more than 10 % of total revenue and sought simply. It shows that the contribution of community forest have not become the foundation of households subsistence, so it is necessary to conduct a study about how is the contribution of community forests management to total household income and it’s feasibility, especially in the Village Babakanreuma, District Sindangagung, Kuningan Regency, West Java Province. The purpose of this study was to identify the system of community forests management and marketing, knowing the contributions community forests management to households total income as well as examine the linkage of effectiveness of community forests area to the households total income and to determine the feasibility of it’s businesses. Determination of the respondents conducted using stratified random sampling method in which the respondents were 36 people obtained from the slovin formula. This study uses a qualitative approach that conducted by survey method using questionnaire and supported by quantitative techniques. The results shows that the contribution of community forests management to the households income has been very visible, reinforced by the magnitude of the contribution value that become higher and increasing in strata. So that the farmers land area of community forest significantly affected their household income. From the data obtained, in 1st strata , the resulting contribution is Rp. 2,208,333.00 per year (7.79%), 2nd strata is Rp 3.800.000,00 per year (11.98%), and 3rd strata is Rp 5.500.000,00 per year (13.00%). Management of community forests is feasible to run on all three strata. These statements are based on the amount of NPV (Net Present Value) that is not negative, BCR (Benefit Cost Ratio) is greater than one and the IRR (Internal Rate of Return) is greater than the prevailing rates. NPV values in strata I, II and III is Rp 6.378.880,00; Rp 14.134.803,00 and Rp 3.985.918.00. Community forests management systems at the sites are still modest. The harvesting is still based on needs and not according to the Sengon plant cycle which is the staple in this village. The timber marketing is only done by a contract system or the middleman (tengkulak) / buyer and furthermore become the responsibility of the middleman / buyer it self.
Keyword: 

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm