Judul: Analisis Faktor yang berpengaruh terhadap Keputusan Pembelian Komik Shonen Studi Kasus Mahasiswa Institut Pertanian Bogor
Abstrak: Komik shonen merupakan salah satu produk budaya popular Jepang yang diminati oleh remaja di Indonesia. Penelitian ini bertujuan untuk menganalisis karakteristik konsumen komik shonen serta menganalisis apakah faktor budaya, sosial, personal dan psikologi konsumen berpengaruh terhadap keputusan pembelian shonen manga. Penelitian ini merupakan penelitian deskriptif kuantitatif. Penelitian ini menetapkan mahasiswa Institut Pertanian Bogor sebagai populasi. Teknik pengambilan sampel dilakukan dengan metode purposive sampling. Data yang digunakan terdiri dari data primer (observasi, kuesioner) dan data sekunder (studi literatur). Teknik analisis data yang digunakan adalah analisis faktor. Hasil penelitian menunjukkan bahwa faktor- faktor baru yang terbentuk dari hasil analisis faktor berpengaruh positif terhadap keputusan pembelian shonen manga oleh konsumen. Hal ini dibuktikan dengan nilai korelasi antar faktor yang bernilai lebih besar dari 0,5.
Keyword: analisis faktor, keputusan pembelian, shonen manga

Judul: Faktor-Faktor yang Memengaruhi Keputusan Pembelian Buku Pada Mahasiswa
Abstrak: Penerbit dan toko buku mengalami penurunan penjualan buku dari tahun 2013 sampai 2020. Dalam penelitian ini peneliti ingin mengetahui apakah faktorfaktor yang menyebabkan penjualan buku mengalami penurunan. Penelitian ini bertujuan mencari faktor-faktor apa saja yang memengaruhi mahasiswa dalam membeli buku. Ada berbagai faktor yang memengaruhi dalam keputusan pembelian buku, yaitu: faktor harga, produk, lokasi, promosi, gaya hidup, word of mouth teknologi, dan informasi. Penelitian ini menggunakan 205 responden yang merupakan mahasiswa IPB University. Teknik pengumpulan data yang digunakan adalah Probability sampling yaitu metode pengambilan sampel secara random atau acak. Pemilihan sampel dengan menggunakan convinience sampling yaitu teknik penarikan sampel dari orang atau unit yang paling mudah dijumpai atau diakses. Metode penarikan sampel menggunakan metode wawancara dan mengisi kuesioner pada google form. Penelitian menggunakan alat uji SEM PLS. SEM (Structural Equation Models) merupakan teknik statistik yang bertujuan untuk membangun maupun menguji model statistik yang biasanya dalam bentuk model sebab akibat. Penelitian ini merupakan bidang ilmu perilaku konsumen. Penelitian dilakukan di kampus Institut Pertanian Bogor bulan Desember 2020 sampai April 2021. Lokasi penelitian dipilih secara sengaja (purposive) karena obyek penelitiannya adalah mahasiswa Institut Pertanian Bogor yang aktif. Hasil penelitian menunjukkan bahwa faktor produk, harga, word of mouth, gaya hidup, teknologi, dan informasi berpengaruh secara positif dan signifikan terhadap keputusan pembelian buku pada mahasiswa. Faktor lokasi, dan promosi tidak berpengaruh secara signifikan terhadap keputusan pembelian buku pada mahasiswa., Publishers and bookstores declined in book sales from 2013 to 2020. The study aimed to find out factors that caused book sales declined and students influencing factors in buying books. There are various factors that influencing the decision to purchase books, i.e price, product, location, promotion, lifestyle, word of mouth technology, and information. This study used 205 respondents who are students of IPB University. The data collection technique used is Probability sampling, a random sampling method. Sample selection using convenience sampling is a sampling technique from the person or unit that is the easiest to find or access. The sampling done by the interview method and filled out a questionnaire on the google form. PLS SEM test tool used to data analysis. SEM (Structural Equation Models) is a statistical technique that aims to build or test statistical models, which are usually causal This research is a field of consumer behaviour science. The research was conducted on the Bogor Agricultural University campus from December 2020 to April 2021. The author chose the location of this research purposively because the object of the research was active Bogor Agricultural University students The study results showed that the product, price, word of mouth, lifestyle, technology, and information factors had a significant effect on students buying book decisions. Location and promotion factors have no significant effect on students purchase book decisions.
Keyword: books, student, purchase decisions, buku, toko buku, keputusan pembelian

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