Judul: Motivasi Menabung dan Aktivitas Menabung Keluarga Pemetik Teh di Desa Purwabakti, Kecamatan Pamijahan, kabupaten Bogor.
Abstrak: Tujuan dari penelitian ini adalah untuk menganalisis pengaruh motivasi menabung keluarga terhadap aktivitas menabung keluarga pemetik teh di Desa Purwabakti, Kecamatan Pamijahan, Kabupaten Bogor, Jawa Barat. Penelitian ini melibatkan 100 keluarga pemetik teh dan dipilih secara acak sederhana. Hasil penelitian menunjukkan bahwa motivasi menabung keluarga pemetik teh berada pada kategori sedang. Sebagian besar keluarga sudah melakukan kegiatan menabung dengan alasan untuk mengatasi apabila terjadi kejadian tidak terduga. Motivasi menabung keluarga memiliki pengaruh positif signifikan terhadap aktivitas menabung keluarga. Artinya, semakin tinggi motivasi menabung keluarga tersebut maka akan menainkkan aktivitas menabung keluarga. Selain itu, pendapatan berpengaruh terhadap motivasi menabung dan aktivitas menabung keluarga.
Keyword: Aktivitas menabung, Motivasi menabung, Pemetik teh, Pendapatan

Judul: Modal Keluarga, Strategi Nafkah, Dan Kesejahteraan Keluarga Buruh Pemetik Teh
Abstrak: Penelitian ini bertujuan untuk menganalisis pengaruh karakteristik keluarga, kepemilikan modal keluarga, dan strategi nafkah terhadap kesejahteraan keluarga. Contoh dalam penelitian ini adalah keluarga dengan istri yang bekerja sebagai buruh pemetik teh di Desa Purwabakti, Kecamatan Pamijahan, Kabupaten Bogor. Contoh dalam penelitian ini sebanyak 100 orang yang dipilih secara acak. Kesejahteraan keluarga diukur dengan menggunakan indikator BKKBN dan BPS. Analisis yang digunakan merupakan analisis deskriptif, uji beda independent sample T-test dan uji regresi logistik. Hasil penelitian menunjukkan umur suami dan besar keluarga berpengaruh negatif signifikan terhadap kesejahteraan keluarga. Modal fisik dan modal finansial berpengaruh positif signifikan terhadap kesejahteraan keluarga. Sementara itu, strategi nafkah tidak berpengaruh signifikan terhadap kesejahteraan keluarga.
Keyword: kesejahteraan keluarga, modal keluarga, strategi nafkah

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