Judul: Consumer's Knowledge and Preference of Yogurt Products in Jambi City
Abstrak: Yogurt merupakan olahan susu fermentasi yang memiliki banyak manfaat bagi tubuh, sehingga dijadikan sebagai produk pangan fungsional. Tujuan penelitian ini untuk mengetahui tentang pengetahuan dan preferensi konsumen terhadap produk yogurt di Kota Jambi. Data dikumpulkan dari 100 responden yang ditentukan dengan metode Purposive Sampling. Data dideskripsikan dan dianalisis menggunakan bantuan Microsoft Excel 2013 dan program Statictical Package for the Social Sciences. Hasil menunjukkan konsumen yogurt di Kota Jambi mayoritas perempuan (70%), berusia ≤ 20 tahun (53%), pendidikan terakhir SMA (64%) dengan status pekerjaan sebagai pelajar atau mahasiswa (84%) yang berpenghasilan <Rp 1.000.000,- per bulan (52%). Masyarakat Kota Jambi mengetahui yogurt dari iklan di televisi/baliho/dll (68,75%) dengan alasan konsumsi rasanya yang enak (51,25%). Konsumsi yogurt secara rutin setiap bulan (58,75%), membeli di supermarket/minimarket (96,25%), mengonsumsi secara langsung (78,75%), menyukai yogurt cair (81,25%) yang dikemas menggunakan botol plastik (60%), dan rasa buah (83,75%). Konsumen menyukai yogurt sebagai camilan (77,5%) yang diminum langsung (86,25%) dengan penyimpanan di kulkas (± 4 ºC) (88,75%). Masyarakat Kota Jambi yang mengonsumsi yogurt memiliki pengetahuan yang kurang baik terhadap produk yogurt (40,6%) karena banyak yang belum mengetahui tentang pembuatan yogurt dan informasi seputar Nomor Kontrol Veteriner (NKV), sehingga belum mempertimbangkan NKV saat memilih yogurt. Faktor-faktor yang memengaruhi preferensi konsumen pangan asal hewan secara berurutan dari yang terbesar yaitu adanya logo halal, adanya masa kadaluarsa, kebersihan tempat berjualan, dan adanya logo NKV., Yoghurt is a fermented dairy product with a lot of benefits to our body, thus it was categorized as a functional food. This paper is aimed to assess the degree of consumers knowledge and their preference of yoghurt products in Jambi City. The research uses 100 samples of people that determined with Purposive Sampling method. Data were presented descriptively and analyzed using Microsoft Excel 2013 and Statistical Package for Social Sciences. The result shows that yoghurt consumers at Jambi City are mainly females (70.00%), aged ≤ 20 years old (53.00%) with a background of high school graduates (64.00%) and currently occupied as students (84.00%) with monthly incomes less than Rp 1.000.000 (52.00%). Study found that people from Jambi knows about yoghurt mainly from TV and billboards (68.75%) with a reason of good taste (51.25%). The majority consumes routinely once in a month (58.75%) consumed directly (78.75%), often buys from supermarket/minimarket (96.25%), preferably thin yoghurt rather than thick and creamy (81.25%), packed in a plastic bottle (60%) with fruit-based flavors (83.75%). Consumers like yoghurt as a beverage (77.50%) and drink directly (86.25%) from a refrigerator (± 4 ºC) (88.75%). Consumers from Jambi have a poor knowledge around yoghurt products (40.60%) because a lot of them have not known about yoghurt manufacture and the information about Veterinary Control Number (NKV), thus not considering NKV as a factor of choosing the products. Factors affecting consumers preferences on choosing animal source foods (ASF)—sorted from the most significant—are the halal logo, expiration date, the hygiene of the store, and the NKV logo.
Keyword: konsumen, nomor kontrol veteriner, pengetahuan, preferensi, yogurt, consumer, knowledge, preference, veterinary control number, yoghurt

Judul: Consumer Nutritional Behavior on Packaged Yoghurt Drinks in Bekasi City
Abstrak: Yoghurt merupakan produk minuman kemasan yang berbahan dasar susu dan sudah melalui proses fermentasi. Yoghurt memiliki peranan penting untuk kesehatan terutama saluran pencernaan. Tujuan penelitian ini adalah mengetahui perilaku gizi konsumen minuman yoghurt kemasan pada masyarakat Kota Bekasi. Desain penelitian ini yaitu cross sectional study dengan 166 responden dari Kota Bekasi. Hasil penelitian menunjukkan bahwa sebagian besar responden memiliki pengetahuan gizi dan sikap gizi tentang yoghurt dengan kategori tinggi. Sikap konsumen terhadap produk yoghurt X dan yoghurt Z termasuk dalam kategori sangat baik. Hasil uji hubungan antara pengetahuan gizi dan sikap gizi menunjukkan bahwa terdapat hubungan signifikan yang cukup dan searah antara pengetahuan gizi dengan sikap gizi. Hasil uji hubungan dengan frekuensi konsumsi yoghurt menunjukkan bahwa terdapat hubungan yang signifikan antara pendapatan perbulan, usia, jenis kelamin, pengetahuan gizi, dan sikap gizi terhadap frekuensi konsumsi minuman yoghurt., Yoghurt is a packaged beverage product made from milk and has gone through fermentation process. Yoghurt has an important role for our health especially for digestive tract. The purpose of this study is to know consumer nutritional behavior on packaged yoghurt drinks in Bekasi City. The design of this study is cross sectional study with 166 respondents from Bekasi City. The results showed most of the respondents has a high category of nutritional knowledge and nutritional attitude. Consumer attitude against the Yoghurt X and Yoghurt Z belongs to the very good category. The results from relationship test shows that there is a suf icient one way significant relationship between nutritional knowledge and nutritional attitude. The results from another relationship test shows that there is a significant relationship between monthly income, age, gender, nutritional knowledge, and nutritional attitude with frequency of yoghurt drinks consumption.
Keyword: Yoghurt, Nutritional Behavior, Nutritional Knowledge, Nutritional Attitude

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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