Judul: Karakteristik Fisik Dan Kimia Yoghurt Beku Dengan Penambahan Krim Dan Penstabil
Abstrak: Penambahan krim dan penstabil dapat mempengaruhi karakteristik yoghurt beku. Penelitian ini menguji pengaruh persentase krim dan penstabil yang berbeda terhadap karakteristik fisik dan kimia yoghurt beku. Penambahan krim dilakukan pada taraf 0%, 4%, dan 8%. Penambahan penstabil dilakukan pada taraf 0.5%, 1.0%, dan 1.5%. Peubah yang diamati terdiri atas : nilai kadar protein, kadar lemak, kadar air, kadar abu, total asam tertitrasi (TAT), pH, daya leleh, dan overrun. Hasil penelitian menunjukkan bahwa penambahan krim dan penstabil tidak nyata mempengaruhi nilai TAT, daya leleh, pH, overrun, dan protein. Penambahan krim dapat menurunkan kadar air dan kadar abu serta meningkatkan lemak yoghurt beku. Penambahan krim pada taraf 8% hanya berpengaruh terhadap sifat kimia yoghurt beku.
Keyword: krim, penstabil, sifat fisik dan kimia, yoghurt beku

Judul: Physicochemical Characteristics, Nutritional Value And Organoleptic Of Synbiotic Yoghurt Gembili Flour (Dioscorea esculenta L.)
Abstrak: Yoghurt merupakan pangan fungsional dari susu yang memiliki variasi jenis, tekstur, dan rasa. Salah satunya adalah yoghurt sinbiotik yaitu susu hasil fermentasi mikroba probiotik dan ditambah prebiotik. Prebiotik terdapat diberbagai bahan pangan, salah satunya umbi gembili (Dioscorea esculenta L.) dengan kandungan inulin sebesar 14,77%. Penelitian bertujuan menganalisis karakteristik fisikokimia, nilai gizi dan organoleptik yoghurt sinbiotik tepung gembili. Penelitian menggunakan Rancangan Acak Lengkap (RAL) untuk mengamati karakteristik fisikokimia (pH, Aw, viskositas, dan total asam titrasi (TAT)), nilai gizi (protein, lemak, air, abu, karbohidrat, gula, dan serat pangan (dietary fiber) serta uji organoleptik. Penambahan tepung gembili berpengaruh nyata (P<0,05) terhadap pH, viskositas, kadar lemak, air, abu, karbohidrat dan serat pangan. Uji hedonik dan mutu hedonik berpengaruh nyata (P<0,05) terhadap warna, rasa, dan tekstur. Formulasi terbaik yaitu penambahan tepung gembili 6% dengan kandungan serat pangan sebesar 4,22% serta telah memenuhi SNI 2981:2009 tentang yoghurt., Yoghurt is a functional food made from milk that comes in various types, textures, and flavors. One is synbiotic yoghurt, which is milk fermented by probiotic microorganisms and supplemented with prebiotics. Prebiotics can be found in various food ingredients, and one of them is the gembili tuber (Dioscorea esculenta L.) tuber, with an inulin content of 14,77%. The research aims to analyze the physicochemical characteristics, nutritional value, and organoleptic of synbiotic yoghurt by adding gembili flour. The research employs a completely randomized design (RAL) to observe the physicochemical characteristics (pH, Aw, viscosity, and total titratable acid (TAT)), nutritional value (protein, fat, moisture, ash, carbohydrates, sugar, and dietary fiber), and organoleptic test. Adding gembili flour significantly affects (P<0.05) the pH, viscosity, fat content, moisture, ash, carbohydrates, and dietary fiber. The hedonic test and hedonic quality significantly affect (P<0,05) the color, taste, and texture. The best formulation is the addition of 6% gembili flour with a dietary fiber content of 4,22%, which meets the Indonesian National Standard (SNI 2981:2009) for yoghurt.
Keyword: gembili flour, nutritional value, physicochemistry, organoleptic, yoghurt

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