Judul: Karakteristik Kimiawi Dadih Susu Sapi Hasil Fermentasi Bakteri Probiotik yang Disimpan pada Suhu Berbeda
Abstrak: Dadih merupakan bahan pangan tradisional dan Sumatera Barat hasil fermentasi alami susu kerbau yang dapat dikembangkan untuk meningkatkan pendapatan dan gizi masyarakat. Kualitas dadih terutama ditentukan oleh kualitas fisik, kandungan nutrisi serta keasamannya. Dadih yang baik secara fisik berwama putih dengan konsitensi yang menyerupai susu asam (yoghurt) dan aroma khas (Sirait et al., 1995). Pengolahan dadih melalui fermentasi yang terkontrol menggunakan probiotik selain meningkatkan kualitas dadih yang dihasilkan diharapkan dapat meningkatkan pula nilai gunanya sebagai pangan fungsionaL Penelitian ini bertujuan untuk mengetahui karaktenstik kimiawi dadih yang dibuat dari susu sapi dengan starter Lactobacillus plantarum (Lp) asal dadih yang dikombinasikan dengan starter probiotik lainnya yaitu. Lactobacillus acidophilus (La) dan Bifidobacterium bifidum (Bf).
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Judul: Karakteristik Dadih dengan Bahan Baku Susu dan Starter yang Berbeda
Abstrak: Dadih merupakan salah satu susu fermentasi yang berasal dari Sumatra Barat yang dibuat dengan cara menuangkan susu kerbau segar ke dalam batang bambu dan diinkubasi pada suhu ruang selama dua hari. Pengembangan dadih di Indonesia menghadapi beberapa kendala, terutama dalam hal ketersediaan susu kerbau. Hasil ternak perah lain seperti susu sapi dan kambing berpotensi untuk menggantikan susu kerbau. Tujuan penelitian ini adalah mempelajari karakteristik dadih yang dibuat dari dua jenis susu (susu sapi dan kambing) dan tiga jenis starter yang berbeda (Starter dadih, Lactobacillus plantarum, Lactobacillus plantarum+Lactobacillus rhamnosus). Hasil analisis ragam menunjukan bahwa susu dan starter yang berbeda tidak mempengaruhi (P>0.05) kadar protein, kadar air, kadar abu, dan total plate count dadih, namun starter yang berbeda berpengaruh nyata (P<0.05) terhadap kadar lemak dan total bakteri asam laktat (BAL) serta berpengaruh sangat nyata (P<0.01) terhadap aktivitas daya hambat terhadap Escherichia coli, viskositas, pH, dan total asam tertitrasi. Jenis susu yang berbeda tidak berpengaruh nyata (P>0.05) terhadap aktivitas daya hambat terhadap E. coli, viskositas, dan kadar lemak dadih namun berpengaruh sangat nyata (P<0.01) terhadap total BAL, pH, dan total asam tertitrasi. Dadih susu sapi dan kambing yang dihasilkan memiliki kualitas nutrisi yang tidak berbeda nyata dan dadih yang dihasilkan dengan starter campuran (L. plantarum+ L. rhamnosus) memiliki jumlah BAL, viskositas, dan aktivitas daya hambat terhadap E. coli yang nyata lebih tinggi dibandingkan dadih dengan starter tunggal. Kata kunci : dadih, fermentasi, kambing, kerbau, sapi
Keyword: dadih, fermentasi, kambing, kerbau, sapi

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