Judul: The Factors that Influence Millennial Consumer Decisions in Buying Fresh Oranges during the Covid-19 Pandemic
Abstrak: Kondisi pandemi Covid-19 menyebabkan tingkat partisipasi konsumsi jeruk oleh rumah tangga tertinggi namun besarnya konsumsi jeruk lebih rendah daripada tahun sebelumnya. Generasi milenial memiliki peluang berkontribusi terhadap konsumsi jeruk tersebut. Penelitian ini bertujuan untuk menganalisis karakteristik konsumen jeruk milenial dan nonmilenial, proses keputusan pembeliannya, dan faktor-faktor yang memengaruhi keputusan konsumen milenial membeli jeruk segar kembali di masa pandemi Covid-19. Data dikumpulkan dengan metode purposive sampling dan quota sampling maka diperoleh 267 responden. Metode analisis yang digunakan yaitu analisis dekriptif, uji chi square, dan uji regresi logistik. Hasil penelitian menunjukkan karakteristik dan keputusan konsumen milenial dan nonmilenial membeli jeruk segar di masa pandemi Covid-19 hampir tidak ada perbedaan karena generasi nonmilenial sebagian besar adalah generasi Z yang tahun kelahirannya dekat dengan generasi milenial. Faktor-faktor yang memengaruhi konsumen milenial membeli jeruk segar kembali di masa pandemi Covid-19 yaitu motif membeli jeruk dan sikap terhadap jeruk segar., The Covid-19 pandemic condition caused the orange consumption participation rate by households become the highest, but the oranges consumption was lower than the previous year. The millennial generation has the opportunity to contribute the oranges consumption. This study aims to analyze the characteristics of millennial and nonmillennial oranges consumers, their purchasing decision processes, and the factors that influence millennial consumers to repurchase fresh oranges during the Covid-19 pandemic. Data were collected by purposive sampling and quota sampling methods, so that 267 respondents were obtained. The analytical method used are descriptive analysis, chi-square test, and logistic regression test. The results of the study show that the characteristics and decisions of millennial and nonmillennial consumers purchase fresh oranges during the Covid-19 pandemic are almost undifferent because the nonmillennial generation is mostly generation Z whose birth year is close with millennial generation. The factors that influence millennial consumers repurchase fresh oranges during pandemic are the motive for buying oranges and attitudes towards fresh oranges.
Keyword: Covid-19, Millennial Generation, Fresh Oranges, Purchasing Decisions, Logistic Regression

Judul: Analysis of the Behavior of Purchasing Health Products through E-Commerce for Millennial Generation during the Covid-19 Pandemi.
Abstrak: Pandemi Covid-19 membuat pemerintah memberlakukan kebijakan Pembatasan Sosial Berskala Besar (PSBB) agar dapat mengurangi penyebaran Covid-19. Hal ini membuat masyarakat untuk melakukan segala aktivitas dari rumah termasuk belanja produk kesehatan agar dapat mengurangi penyebaran virus. Tujuan dari penelitian ini adalah (1) menganalisis karakteristik generasi milenial dalam melakukan pembelian produk kesehatan di masa Pandemi Covid- 19, (2) menganalisis perbedaan perilaku kesadaran akan kesehatan sebelum dan sesudah pandemi Covid-19, (3) menganalisis pengaruh variabel theory of planned behavior terhadap intensi generasi milenial dalam melakukan pembelian produk kesehatan pada masa pandemi Covid-19. Metode pengolahan data menggunakan analisis deskriptif, uji wilcoxon, analisis SEM-LISREL, dan net promoter score. Hasil penelitian ini menunjukkan bahwa netizen yang mempengaruhi konsumen saat memutuskan pembelian produk kesehatan. Sehingga dalam perilaku pembelian produk kesehatan di masa Pandemi Covid-19 netizen atau pembeli lain yang mempengaruhi konsumen dalam memutuskan produk kesehatan yang dibeli.
Keyword: belanja online, LISREL-SEM, produk kesehatan, theory of planned behavior

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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