Judul: Pengaruh Perceived Usefulness, Perceived Ease of Use, dan Perceived Risk terhadap Intention to Reuse ShopeePay pada Masa Pandemi COVID-19
Abstrak: World Health Organization telah menganjurkan kebijakan physical distancing untuk mengurangi kontak fisik, termasuk transaksi pembayaran selama masa pandemi COVID-19. Pembayaran digital merupakan salah satu alternatif untuk mengurangi risiko selama masa pandemi COVID-19. Salah satu pembayaran digital teratas selama masa pandemi COVID-19 ialah ShopeePay. Penelitian ini secara garis besar bertujuan untuk menganalisis pengaruh perceived usefulness, perceived ease of use, dan perceived risk terhadap intention to reuse ShopeePay di Jabodetabek. Responden pada penelitian ini sebanyak 492 responden. Teknik penentuan sampel dilakukan menggunakan non probability sampling dengan metode judgmental sampling. Teknik analisis data yang digunakan adalah analisis deskriptif dan SEM PLS. Hasil dari penelitian ini menunjukkan bahwa perceived usefulness, perceived ease of use, dan perceived risk memiliki pengaruh positif signifikan terhadap Intention to Reuse ShopeePay pada masa pandemi COVID-19. Kata kunci : Intention to Reuse, perceived usefulness, perceived ease of use, perceived risk, shopeepay, World Health Organization has recommended a physical distancing policy to reduce physical contact, including payment transactions during the COVID-19 pandemic. Digital payments are an alternative to reduce risk during the COVID-19 pandemic. One of the top digital payments during the COVID-19 pandemic was ShopeePay. This study broadly aims to analyze the effect of perceived usefulness, perceived ease of use, and perceived risk on the Intention to Reuse ShopeePay in Jabodetabek. Respondents in this study were 492 respondents. The sampling technique was carried out using non probability sampling with judgmental sampling method. The data analysis technique used is descriptive analysis and SEM PLS. The results of this study indicate that perceived usefulness, perceived ease of use, and perceived risk have a significant positive effect on ShopeePay's Intention to Reuse during the COVID-19 pandemic. Keywords: Intention to Reuse, perceived usefulness, perceived ease of use, perceived risk, shopeepay
Keyword: Intention to Reuse, Perceived Usefulness, Perceived Ease of Use, Perceived Risk, ShopeePay

Judul: The Effect of Online Consumer Review and Rating  on Purchase Intention of Health Products on Shopee E-Marketplace During the  Covid-19 Pandemic in Jabodetabek
Abstrak: Pandemi COVID-19 menyebabkan peningkatan pembelian produk-produk kesehatan seperti masker, handsanitizer, obat-obatan dan lain-lain. Shopee merupakan salah satu e-marketplace yang sedang berkembang di Indonesia dan menyediakan fitur online consumer review dan rating pada platformnya. Penelitian ini bertujuan untuk menganalisis pengaruh online consumer review dan rating terhadap minat beli produk kesehatan pada e-marketplace Shopee selama masa pandemi COVID-19 di Jabodetabek. Penarikan sampel dilakukan dengan teknik purposive sampling. Metode yang digunakan dalam penelitian ini adalah analisis deskriptif dan SEM-PLS. Hasil analisis menunjukkan variabel online consumer review dan rating berpengaruh positif dan signifikan terhadap minat beli produk kesehatan dengan variabel rating memiliki pengaruh lebih dominan., COVID-19 pandemic led to an increase in purchases of health products such as masks, handsanitizers, medicines and others. Shopee is one of the growing online marketplaces in Indonesia that provides online consumer review and rating features on its. This study aimed to analyze the effect of online consumer review and rating on purchase intention of health products on shopee online marketplace during the COVID-19 pandemic. The sampling method used in this study was purposive sampling technique. The method used in this research was descriptive analysis and SEM-PLS. The results of the analysis show that online consumer review and rating variables have a positive and significant effect on purchase intention in health products with the rating variable as the dominant influence.
Keyword: Health Products, Online Consumer Review, Purchase Intention, Rating, Shopee

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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