Judul: Pengaruh kemasan dan goncangan terhadap mutu fisik jambu biji (Psidium guajava L.) selama transportasi
Abstrak: Indonesia merupakan negara penghasil komoditas hortikultura yang potensial. Jambu biji sebagai salah satu jenis produk hortikultura tropis memilii kandungan gizi yang tinggi. Akan tetapi, di Indonesia tidak banyak daerah penghssil jambu biji. Beberapa daerah penghasil jambu biji adalah Sumatra Utara, Jawa Tengah, NTB, Bali, dan Jawa Barat (Cianjur, Bandung, Purwakarta). Oleh karena itu diperlukm transportasi untuk pemasaran buah berkhasiat tersebut ke berbagai wilayah di Indonesia.
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Judul: Kajian Teknik Penyimpanan dan Pengemasan Jambu Biji (Psidium guajava L.)
Abstrak: Indonesia merupakan negara penghasil komoditas hortikultura yang potensial. Buah-buahan sebagai komoditas hortikultura memiliki potensi untuk dikembangkan baik untuk memenuhi kebutuhan dalam negeri maupun luar negeri. Di daerah tropis, buah dan sayuran cepat mengalami kerusakan terutama disebabkan oleh kondisi suhu dan kelembaban lingkungan. Kurangnya penanganan pasca panen (pengangkutan, sortasi, pengemasan dan penyimpanan) ikut mempengaruhi nilai perubahan mutu dari produk. Perubahan mutu selama proses penyimpanan terjadi karena buah-buahan dan sayuran masih melakukan respirasi, dimana selama proses respirasi tersebut produk mengalami pematangan dan kemudian diikuti dengan proses pembusukkan. Kecepatan respirasi produk tergantung dari suhu penyimpanan, ketersediaan oksigen untuk berespirasi dan karakteristik produk itu sendiri. Jambu biji merupakan salah satu jenis buahbuahan yang belum mendapatkan perhatian khusus di Indonesia. Umumnya jambu biji diperdagangkan dalam keadaan segar setelah dipetik. Masalah yang sering dihadapi setelah panen adalah keadaan teksturnya yang mudah rusak akibat pengaruh mekanis, disamping tingkat kematangannya yang sering kali tidak merata dan penentuan suhu penyimpanan pun menjadi kendala sehingga menurunkan nilai jualnya. Buah jambu yang menjadi matang selama pengangkutan atau selama proses penyimpanan, dalam kondisi lingkungan yang kurang baik akan menyebabkan buah jambu mengalami kerusakan, baik dalam penampakan, kepadatan, aroma dan nilai gizi
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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