Judul: Physicochemical Characteristics, Microbiology and  Market Test of Strawberry Rosela Yogurt Smoothies on Teenagers and Adults in  Bogor
Abstrak: Yogurt smoothies rosela stroberi merupakan yogurt yang telah mengalami perlakuan pengurangan kadar air dan penambahan ekstrak bunga rosela serta selai stroberi. Sebelum dipasarkan, produk ini perlu diuji keamanan serta peluang pasarnya. Penelitian ini bertujuan menganalisis karakteristik fisikokimia, mikrobiologi dan uji pasar yogurt smoothies rosela stroberi pada usia remaja dan dewasa di Bogor. Karakteristik fisikokimia yang diuji meliputi pH, aktivitas air (aw), viskositas dan total asam tertitrasi. Parameter mikrobiologi yang diuji adalah total bakteri asam laktat dan cemaran Salmonella sp . Parameter uji pasar yang diuji meliputi analisis persepsi dan preferensi konsumen serta korelasinya terhadap pola konsumsi yogurt. Uji pasar yang dilakukan menggunakan 100 orang responden yang terdiri dari 50 orang siswa SMAN 1 Bogor dan 50 orang Mahasiswa IPB University. Hasil penelitian menunjukkan karakteristik fisik (pH, aktivitas air, viskositasdan total asam laktat) telah memenuhi persyaratan SNI mutu yogurt. Karakteristik kima atau kandungan nutrisi serta karakteristik mikrobiologi yogurt smoothies telah memenuhi persyaratan mutu standar yogurt berdasarkan SNI. Hasil penelitian menunjukkan responden memiliki persepsi yang baik serta preferensi suka terhadap atribut yogurt smoothies. Preferensi konsumen mengenai warna kemasan, bahan kemasan, bentuk kemasan, keterangan dalam kemasan, rasa yogurt serta tekstur yogurt memiliki korelasi yang positif dengan rentang harga yogurt yang dibeli, frekuensi konsumsidan volume konsumsi yogurt., Strawberry Rosela Yogurt Smoothie is yogurt that has been processed by reducing the water content and adding rosela flower extract and strawberry jam. Before being marketed, these products need to be tested for safety and market opportunities. This study aims to analyze the physicochemical characteristics, microbiology and market tests of strawberry rosela yogurt smoothies in adolescents and adults in Bogor. The physicochemical characteristics tested included pH, water activity (aw), viscosity and total titrated acid. The microbiological parameters tested were total lactic acid bacteria and Salmonella sp. The market test parameters tested include analysis of consumer perceptions and preferences and their correlation with yogurt consumption patterns. The market test was carried out using 100 respondents consisting of 50 students from SMAN 1 Bogor and 50 students from IPB University. The results showed that the physical properties (pH, water activity, viscosity, and total lactic acid) fulfilled the SNI yogurt quality requirements. The chemical properties or nutritional content and microbiological properties of yogurt smoothies have met the requirements for yogurt quality standards based on SNI. The results showed that respondents had good perceptions and preferences on the attributes of smoothies yogurt. Consumer preferences regarding packaging color, packaging material, packaging shape, packaging description, yogurt taste and yogurt texture are positively correlated with the price range of yogurt purchased, frequency of consumption, and volume of yogurt consumption.
Keyword: karakteristik fisikokimia, karakteristik mikrobiologi, persepsi konsumen, preferensi konsumen

Judul: Characteristics and market test of dried yoghurt in adolescent and adults consumer in Bogor City
Abstrak: Yoghurt adalah minuman fermentasi yang mengandung bakteri probiotik. Dried yoghurt merupakan salah satu inovasi produk yoghurt. Dried yoghurt lebih banyak beredar luas diluar negeri dibandingkan didalam negeri dan umumnya diluar negeri sudah sangat dikenal. Oleh sebab itu perlu identifikasi karakteristik dan uji pasar. Uji pasar meliputi bagaimana potensi pasar, persepsi konsumen, respon (tanggapan) konsumen terhadap dried yoghurt, kemudian perilaku pembelian konsumen dan atribut-atribut yang mempengaruhi pembelian dried yoghurt yang dilakukan oleh remaja dan dewasa di Kota Bogor. Dried yoghurt belum pernah dipasarkan sehingga dilakukan analisis deskriptif perilaku pembelian dried yoghurt diperlukan untuk melihat bagaimana perilaku pembelian dried yoghurt yang dilakukan oleh konsumen di Kota Bogor. Pengambilan sampel dilakukan dengan menggunakan rumus slovin dengan nilai kritis sebesar 10 % maka total sampel yang diambil adalah 100 orang. Pengambilan sampel dilakukan secara purposive sampling. Dried yoghurt aman dikonsumsi berdasarkan karakateristiknya sesuai dengan SNI dan berpotensi dipasarkan di Kota Bogor karena banyak remaja dan dewasa yang sadar akan kesehatan. Hasil analisis conjoint dried yoghurt produsen harus mendesain dried yoghurt dengan kandungan probiotik, kemasan produk harus sesuai dengan selera konsumen dalam hal ini konsumen lebih menyukai dried yoghurt dengan kemasan 7 gram. Konsumen lebih menyukai jika harga dried yoghurt 10.000/pcs. Berdasarkan hasil analisis deksriminan memperlihatkan dari 100 responden sebanyak 90 orang akan membeli dried yoghurt jika dipasarkan. Kemudian 4 orang tidak akan membeli dried yoghurt jika dipasarkan dan 6 orang ragu-ragu terhadap pilihannya. Berdasarkan hasil penelitian menunjukan bahwa dari 100 responden terdapat 47 orang perempuan dan 53 orang laki-laki dengan keluarga besar berjumlah 4 orang, pekerjaan sebagai pelajar/mahasiswa, berpendidikan terakhir SMP-SMA/Sederajat dengan pendapatan dan pengeluaran rata-rata sebulan sebesar Rp 500.000 – Rp 1.500.000. Dried yoghurt berpotensi dipasarkan di Kota Bogor karena banyak remaja dan dewasa yang sadar akan kesehatan. Rekomendasi pemasaran dried yoghurt yaitu memproduksi dried yoghurt sesuai dengan selera konsumen yaitu dried yoghurt dengan kandungan probiotik, harga yang terjangkau, berat produk yang lebih banyak dan kemasan yang menarik., Yoghurt is a fermented drink that contains probiotic bacteria. Dried yoghurt or dry yoghurt is one of the innovations of yoghurt products. Dried yoghurt is more widely circulated abroad than domestically and generally abroad is very well known. Therefore, it is necessary to identify characteristics and test the market. Market Test includes how the market potential, consumer perception, consumer response (response) to dried yoghurt, then consumer purchasing behavior, and attributes that influence the purchase of dried yoghurt made by adolescents and adults in Bogor City. Dried yoghurt has never been marketed so a descriptive analysis of dried yoghurt buying behavior is needed to see how dried yoghurt buying behavior is carried out by consumers in Bogor City. Sampling is carried out using the Slovin formula with a critical value of 10% then the total sample taken is 100 people. Sampling is carried out by purposive sampling. Dried yoghurt is safe for consumption based on its characteristics in accordance with SNI and has the potential to be marketed in Bogor City because many adolescents and adults are health-conscious. Results of conjoint analysis dried yoghurt, producers must design dried yoghurt with probiotic content, the product packaging must be in
Keyword: dried yoghurt, marketing, development, 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