Judul: Hubungan Beberapa Karakteristik dan Perilaku Komunikasi Pemuka-Pemuka Tani dalam Diseminasi Teknologi Model Farm di Daerah Aliran Sungai (DAS) Citanduy Ciamis Jawa Barat
Abstrak: Penelitian ini bertujuan untuk: (1) mengetahui distribusi pemuka tani model farm dan dampak diDAS Citanduy menurut karakteristik mereka yang diamati, (2) mengetahui perilaku komunikasi pemuka tani itu dalam proses diseminasi teknologi model farm, dan (3) mengukur derajat hubungan antara perilaku komunikasi pemuka tani itu dengan beberapa karakteristik sosial ekonomi mereka yang diamati.
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Judul: Hubungan beberapa karakteristik terpilih petani model farm dengan perilaku mereka mendengarkan radio: kasus studi di beberapa desa di daerah aliran sungai Citanduy
Abstrak: Penelitian ini bertujuan untuk: (1). mempelajari distribusi petani model farm di DAS Citanduy menurut karakteristik mereka yang diamati, (2). mengidentifikasi perilaku penggunaan radio petani model farm di DAS Citanduy, dan (3) mengukur derajat hubungan antara perilaku petani model farm mendengarkan radto dengan beberapa karakteristik mereka yang diamati. Desain penelitian merupakan suatu survai yang bersifat Diskriftif. Peubah anteseden yang digunakan adalah beberapa karakteristik petani model farm yang meliputi ( 1 ) umur, (2) jenis kelamin, (3) pendidikan (formal, non-formal, informal ) , ( 4) penguasaan bahasa ( indonesia dan sunda) , ( 5 ) pendapatan keluarga, dan ( 6) kekosmopolitan (frekuensi ke kota, frekuensi mengunjungi penyuluh pertanian, frekuensi surat menyurat tentang pertanian, frekuensi mengunjungi petanian, keterdedahan televisi dan keterdedahan media cetak). Sedangkan peubah konsekuensinya adalah perilaku petani mendengarkan radio yang meliputi: ( 1) jenis acara s i a ran yang di den gar, ( 2) tempat mendengarkan, ( 3) waktu mendengarkan, ( 4) frekuensi menden garkan, ( 5) lama mendengarkan, dan (6) cara mendengarkan radio. Pengumpulan data di lakukan selama dua bulan (Pebruari-Maret 1.988). Data primer di kumpulkan langsung dari responden dengan cara wawancara (terstruktur dan bebas) dan observasi langsung di lapangan. Sampel penelitian diambil 60 persen sub DAS dari populasi sebanyak 5 sub DAS, dan masing-masing 30 persen model farm dari total populasi 69 model farm. Sampel petani diambil sebanyak masing-masing 10 persen dari 1500 petani model farm di sub DAS yang terpilih (Ci t anduy H ulu 30 o r a n g, Ci s e el 70 orang, dan Cijolang 50 orang). Data yang diperoleh dianalisis dengan menggunakan perhitungan nilai tengah frekuensi distribusi. Sedangkan untuk analisis hubungan digunakan prosedur khiKuadrat (Chi-Square). ...
Keyword: River basin

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