Judul: Risiko Produksi Padi Sehat Dan Padi Anorganik Di Kecamatan Cigombong, Kabupaten Bogor Jawa
Abstrak: Kesadaraan akan bahaya yang timbul dari penggunaaan bahan kimia sintetis dalam pertanian, mendorong petani untuk mengurangi bahan kimia yang digunakan dalam budidaya. Daerah yang telah mengembangkan pertanian berkelanjutan adalah Kabupaten Bogor, dengan fokus pada komoditas padi sehat (semi-organik). Tujuan dalam penelitian ini untuk menganalisis perbandingan risiko produksi antara petani padi sehat dan petani anorganik. Data yang diperoleh dari petani padi sehat dan petani padi anorganik dipilih menggunakan teknik purposive sampling. Penelitian menggunakan pendekatan hasil produksi dan struktur pendapatan petani. Hasil menunjukan bahwa produksi dari petani padi sehat lebih rendah daripada petani padi anorganik serta petani padi sehat memiliki risiko produksi lebih tinggi daripada petani padi anorganik. Kesimpulnya adalah sebagai produsen petani padi sehat memberikan pendapatan lebih sedikit dibandingankan petani padi anorganik.
Keyword: padi sehat, risiko produksi, pendapatan petani

Judul: Manajemen risiko produksi dan penerimaan padi semi organik (Studi : petani gabungan kelompok tani silih asih di Desa Ciburuy, Kec. Cigombong, Kab. Bogor)
Abstrak: Indonesia sebagai negara agraris memiliki potensi pertanian yang mentpakan penyumbang pertumbuhan ekonomi terbesar Indonesia, yaitu sebesar 19,3 persen, terjadi pada triwulan pertama tahun 2009. Preferensi konsumen terhadap pangan yang terbebas dari unsur-unsur kimia yang dapat menyebabkan gangguan kesehatan, menyebabkan pengalihan minat konsumen terhadap produk organik. Petani yang tergabung dalam Gabungan Kelompok Tani Silih Asih memiliki Standar Operasional Prosedur (SOP), dimana input yang digunakan dalam sarana tani mengacu pada pengendalian dan pencegahan hama penyakit melalui pestisida nabati. Proses produksi padi semi organik sangat dipengaruhi iklim kemarau, fluktuasi produktifitas, harga penjualan, dan penerimaan yang mengindikasikan adanya risiko usaha. Penelitian ini bertujuan untuk, (1) mengidentifikasi sumber-sumber risiko produksi dan risiko penerimaan padi semi organik yang terjadi pada petani, (2) menganalisis dampak risiko yang disebabkan oleh sumber-sumber risiko pada kegiatan produksi padi semi organik terhadap petani, dan (3) menganalisis strategi penanganan risiko pada petani yang tergabung dalam Gapoktan Silih Asih.
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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