Judul: Faktor-Faktor Lingkungan Dan Teknik Budidaya Yang Berkaitan Dengan Penyakit Kanker Batang Kopi Di Kabupaten Tanggamus, Lampung.
Abstrak: Tanaman kopi merupakan salah satu komoditas penting di Indonesia. Kopi memiliki nilai ekonomi penting dan merupakan salah satu komoditas ekspor terbesar Indonesia. Hama dan penyakit menjadi salah satu faktor pembatas dalam produksi kopi. Salah satu penyakit yang menyerang tanaman kopi adalah penyakit kanker batang kopi. Penyakit kanker batang kopi merupakan penyakit baru dan belum diketahui penyebabnya. Tujuan penelitian ini adalah mengetahui faktor– faktor lingkungan dan teknik budidaya yang berkaitan dengan penyakit kanker batang kopi di Kabupaten Tanggamus, Lampung. Metode yang dilaksanakan meliputi pengambilan data sekunder, metode wawancara petani, serta pengamatan langsung kejadian dan keparahan penyakit di lapangan. Hasil penelitian ini menunjukkan bahwa faktor-faktor yang berkaitan dengan perkembangan penyakit kanker batang kopi adalah umur tanaman kopi, frekuensi penggunaan herbisida, kurangnya pemupukan, dan curah hujan yang mengalami peningkatan selama sepuluh tahun terakhir.
Keyword: Kanker batang, kopi, penyakit

Judul: Potential Attack of Coffee Berry Borer (Hypothenemus hampei Ferr.) Based on Climatic Conditions in Tanggamus Regency
Abstrak: Kopi merupakan salah satu komoditas andalan dalam sektor perkebunan di Indonesia. Salah satu sentra kopi di Indonesia ada di Provinsi Lampung dengan kontribusi 17% dari produksi kopi nasional. Hama penggerek buah kopi (Hypothenemus hampei Ferr.) menjadi hama utama yang menyerang tanaman kopi di Indonesia yang menyebabkan penurunan hasil panen dan kualitas biji kopi. Kabupaten Tanggamus merupakan salah satu kabupaten di Provinsi Lampung dengan produksi kopi sebesar 34.129 ton pada tahun 2020. Penelitian ini bertujuan untuk menganalisis potensi serangan hama penggerek buah kopi (Hypothenemus hampei Ferr.) di Kabupaten Tanggamus berdasarkan nilai ecoclimatic index (EI) menggunakan model Climex dengan periode tahun 1989- 2018. Nilai EI di Kabupaten Tanggamus memiliki rentang nilai 71 sampai 97 yang menandakan hama BPKo sesuai dengan kondisi iklim di Kabupaten Tanggamus. Indeks stress (SI) menjadi faktor yang membatasi perkembangan hama penggerek buah kopi di Kabupaten Tanggamus pada tahun 1989, 1991, 1997, 2008, 2012 dan 2015. Dry stress (DS) terjadi tiga kali yaitu tahun 1991, 1997 dan 2015, kejadian dry stress (DS) tersebut dipicu karena adanya penurunan rata-rata curah hujan yang menyebabkan nilai soil moisture (SM) berada dibawah nilai ambang batas dry stress (SMDS). Selain itu, ketinggian tempat mempengaruhi nilai EI hama penggerek buah kopi di Kabupaten Tanggamus, semakin tinggi suatu tempat maka nilai EI akan semakin rendah., Coffee is one of the prime commodities in the plantation sector in Indonesia. One of the coffee growing hubs in Indonesia is Lampung with a 17% contribution to the national coffee production. The coffee berry borer (Hypothenemus hampei Ferr.) is the main pest that attacks coffee plants in Indonesia, which leads to a decrease in yield and quality of coffee beans. Tanggamus Regency is a one of the regency in Lampung Province with 34.129 tons of coffee production in 2020. This research aims to analyze the potential attack of coffee berry borer pests (Hypothenemus hampei Ferr.) in Tanggamus Regency based on the ecoclimatic index (EI) value using the Climex model with the period 1989-2018. The EI value in Tanggamus Regency has a value range from 71 to 97, which indicates that BPKo pests are compatible with the climatic conditions in Tanggamus Regency. The stress index (SI) is a factor that limits the development of coffee berry borer in Tanggamus Regency in 1989, 1991, 1997, 2008 and 2015. Dry stress (DS) occurred three times in 1991, 1997 and 2015, which was triggered by a decrease in average rainfall, causing the soil moisture (SM) value to be below the dry stress threshold value (SMDS). In addition, the altitude of the place affects the EI value of coffee berry borer pests in Tanggamus Regency, as the higher the place, its EI value will be lower.
Keyword: Climex, ecoclimatic index, altitude, pest compatibility

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