Judul: Analysis of Student Behaviour towards Beef  Consumption Before and During COVID-19 Pandemic
Abstrak: Daging sapi merupakan salah satu pangan yang permintaan meningkat setiap tahun. Konsumsi daging sapi akan meningkat seiring dengan pertumbuhan pendapatan nasional, namun kondisi tersebut tidak dapat dipastikan akibat pandemi COVID-19. Tujuan penelitian ini yaitu menganalisis perubahan perilaku konsumsi daging sapi dari masa sebelum pandemi dan selama pandemi COVID-19 berlangsung. Penelitian ini menggunakan data primer yang diperoleh melalui metode wawancara dengan google form. Kriteria responden merupakan mahasiswa di Indonesia. Hasil data yang diperoleh dianalisis secara deskriptif. Hasil penelitian menunjukkan bahwa perubahan perilaku mahasiswa terhadap konsumsi daging sapi relatif tidak berbeda dari sebelum pandemi hingga berlangsungnya pandemi COVID-19., Beef is one type of food that has an increasing demand level each year. Nationally, beef consumption will rise along with the growth of income, however, the current condition cannot be ascertained because of the COVID-19. The purpose of this research is to analyse the behavioural change of beef consumption before and during the COVID-19 Pandemic. This research use primary data which obtained through survey method using google from. The criteria of the respondent Indonesian collage student. The result from this research shown that beef consumption behaviour relatively did not change before until the pandemic COVID-19 continuous.
Keyword: beef consumption, behaviour, pandemic

Judul: Analisis Minat Beli Konsumen pada Produk Daging Olahan dengan Sistem Keterlacakan QR (Quick Response) Code di Masa Pandemi COVID-19
Abstrak: Sejak terjadinya pandemi COVID-19, masyarakat menjadi lebih selektif terhadap bahan pangan yang dikonsumsi dan industri pengolahan daging dalam negeri mengalami penurunan permintaan. Salah satu solusi untuk produk daging olahan yang aman serta berkualitas adalah sistem keterlacakan QR Code. Penelitian ini bertujuan untuk menganalisis minat beli konsumen terhadap produk daging olahan dengan sistem keterlacakan QR Code semasa pandemi COVID-19 di Jakarta melalui integrasi model berdasarkan pendekatan Theory of Planned Behaviour (TPB), Technology Acceptance Model (TAM), variabel health consciousness, media exposure, serta habits. Responden yang diperoleh sebanyak 230 orang. Data yang digunakan dalam penelitian ini merupakan data primer dan data sekunder. Penelitian ini menggunakan metode analisis deskriptif dan SEM-PLS. Hasil dari penelitian ini adalah subjective norms dan attitude memengaruhi purchase intention secara langsung. Media exposure memengaruhi purchase intention melalui health consciousness, perceived information, dan attitude. Perceived information memengaruhi purchase intention melalui perceived usefulness. Perceived usefulness memengaruhi purchase intention melalui attitude. Perceived Ease of Use memengaruhi purchase intention melalui perceived usefulness dan attitude. Health Consciousness dan Habits tidak berpengaruh langsung dengan purchase intention, tetapi health consciousness berpengaruh baik dengan habits, habits berpengaruh baik dengan attitude yang berpengaruh baik dengan purchase intention., Since the COVID-19 pandemic, people become selective on food and the domestic meat processing industry has experienced a decline in demand. One of the solutions for safe processed meat products is the QR Code traceability system. This study aims to analyse consumer’s purchase intention towards traceable processed meat products with QR Code during the COVID-19 pandemic in Jakarta through model integration based on the approach of Theory of Planned Behavior (TPB), Technology Acceptance Model (TAM) and variables including health consciousness, media exposure, as well as habits. Total respondents obtained were 230 people. This research uses descriptive analysis method and SEM-PLS with primary data and secondary data. The results show that subjective norms and attitudes directly affect purchase intention. Media exposure affects purchase intention through health consciousness, perceived information, and attitude. Perceived information affects purchase intention through perceived usefulness. Perceived usefulness affects purchase intention through attitude. perceived ease of use affects purchase intention through perceived usefulness and attitude. health consciousness and habits do not have a direct effect on purchase intention, but health consciousness has a good effect on habits, habits have a good effect on attitude which has a good effect on purchase intention.
Keyword: COVID-19, Processed Meat Products, Purchase Intention, QR Code, Traceability System

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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