Judul: Analisis Sikap Konsumen Pada Masa Pandemi Covid-19 dan Pengaruhnya Terhadap Keputusan Pembelian di Coffee Shop Jabodetabek
Abstrak: Pandemi Covid-19 berdampak negatif pada berbagai macam jenis usaha secara langsung termasuk coffee shop yang merupakan tempat orang melakukan interaksi dan berkumpul. Tujuan penelitian adalah untuk menganalisis pengaruh sikap konsumen pada pandemi Covid-19 terhadap keputusan pembelian di coffee shop. Sampel dari penelitian ini adalah masyarakat di Jabodetabek sebanyak 100 orang menggunakan metode non-probability sampling dan teknik purposive sampling. Pengambilan data sampel dilakukan dengan menyebarkan kuesioner ke konsumen yang pernah melakukan kunjungan coffee shop di Jabodetabek . Analisis dilakukan dengan metode Structural Equation Modelling (SEM). Hasil analisis menunjukkan konsumen mengetahui dan meyakini pandemi Covid-19 dan protokol kesehatan. Konsumen juga menerapkan protokol kesehatan Covid-19 dari pemerintah. Sikap konsumen pada masa pandemi ini berpengaruh negatif terhadap keputusan pembelian di coffee shop Jabodetabek
Keyword: Attitudes, Coffee Shop, Covid-19 Pandemic, Purchase Decision, SEM

Judul: Pengaruh Social Media Marketing terhadap Minat Konsumen Membeli Produk Imaji Kopi Selama Masa Pandemi COVID-19
Abstrak: Kopi merupakan salah satu minuman yang banyak dikonsumsi oleh masyarakat Indonesia. Hal ini membuat meminum kopi menjadi sebuah gaya hidup baru di masyarakat. Tingginya minat konsumen terhadap coffee shop membuat semakin bertambahnya jumlah coffee shop di berbagai kota, termasuk Kota Bontang. Semakin banyaknya coffee shop bermunculan, membuat persaingan semakin ketat. Penelitian ini bertujuan untuk dapat melihat pengaruh dari social media marketing terhadap minat konsumen melakukan pembelian di Imaji Kopi. Penelitian ini menggunakan Structural Equation Model (SEM-PLS) sebagai metode penelitian. Hasil penelitian menunjukkan bahwa dari lima indikator terdapat tiga indikator yang berpengaruh signifikan dan dua indikator tidak berpengaruh signifikan. Indikator yang berpengaruh signifikan adalah Trendiness, Connecting dan Customization. Sedangkan indikator content sharing dan content creation tidak berpengaruh signifikan., Coffee is one of a drinks that is consumed by Indonesians. This phenomenon made the new lifestyle among Indonesian youngsters. The hype about coffee can be seen everywhere, including in Bontang. The interest of building a coffee shop is higher and higher among the people and it sure affects the market rivalry between others. The purpose of this study is to analysis the effect of social media marketing on consumer's interest to buy coffee from Imaji Kopi. This study is using the Structural Equation Model (SEM-PLS) as the methodology. The result of the study showed that from five indicators, only three indicators showed significant effect while the other two didn't show any significant effect. The significant indicators are Trendiness, Connecting and Customization. The other indicators, namely Sharing and Content Creation, didn't show any significant effect.
Keyword: Coffee Shop, Purchase Intention, Social Media Marketing, Structural Equation Model

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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