Judul: Gejala burik pada buah manggis: asosiasi trips (Thysanoptera: Thripidae) dengan bunga dan buah manggis (Garcinia mangostana)
Abstrak: Scar or mangosteen fruit is one of the problems in increasing the fruit export volume of Indonesia. Scar is a kind of fruit damage that occurs on the surface of the skin (exocarp) that could reduce consumer's interest. The source of sear appearance in mangosteen fruit has not been explored well, but presumably that is because of the activity of thrips.
Keyword: 

Judul: Inventarisasi Hama Manggis (Garcinia mangostana L.)  Di Kebun Manggis Pusat Kajian Buah Tropika,  Tajur, Bogor, Jawa Barat
Abstrak: Manggis adalah salah satu komoditas buah tropis yang sangat potensial untuk dikembangkan khususnya sebagai komoditas ekspor. Budidaya manggis tidak dapat lepas dari adanya organisme pengganggu tanaman seperti hama. Namun sampai saat ini informasi mengenai hama manggis masih terbatas sehingga perlu dilakukan penelitian mengenai hama yang menyerang tanaman manggis. Penelitian ini bertujuan untuk mengetahui jenis-jenis hama pada tanaman manggis di kebun manggis Pusat Kajian Buah Tropika, Tajur, Bogor, Jawa Barat. Selain itu dihitung juga persen tanaman terserang dan luas serangan pada daun muda hama yang paling dominan, yaitu pengorok daun manggis. Penelitian diawali dengan menentukan lahan tanaman manggis yang akan diteliti. Pengamatan dilakukan pada bagian-bagian tanaman yaitu bunga, daun, ranting dan batang tanaman manggis. Serangga yang tidak dapat diidentifikasi di tempat dibawa ke Laboratorium Biosistematika Serangga sebagai sampel untuk dipelihara sampai fase imago khususnya untuk serangga dari ordo Lepidoptera. Sampel serangga yang sudah imago dibuat koleksi kering untuk diidentifikasi. Serangga dari ordo Thysanoptera dan Hemiptera yang ditemukan di lapang langsung dimasukkan ke dalam botol film yang berisi alkohol 70% dan kemudian dibuat preparat mikroskop untuk diidentifikasi. Hasil identifikasi didapat jenis hama yang merusak tanaman manggis yaitu Phyllocnistis sp. (Lepidoptera: Gracillariidae), ulat kantung (Lepidoptera: Psychidae), ulat jengkal (Lepidoptera: Geometridae), ulat manggis (Lepidoptera: Noctuidae), ulat pelipat daun (Lepidoptera), Toxoptera aurantii (Hemiptera: Aphididae), Pseudococcus cryptus Hempel dan Exallomochlus hispidus Morrison (Hemiptera: Pseudococcidae) serta Thrips hawaiiensis Morgan dan Selenothrips rubrocinctus Giard (Thysanoptera: Thripidae). Persen tanaman terserang di kedua petak pengamatan mencapai 100%. Persen daun muda terserang rata-rata sebesar 11,55% di petak I dan 13,37% di petak 2. Musuh alami yang ditemukan adalah parasitoid dari Famili Eulophidae dan Braconid
Keyword: 

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