Judul: Pengaruh Rating dan Online Customer Review Terhadap Keputusan Pembelian di E-commerce Shopee
Abstrak: Kemajuan teknologi informasi menimbulkan adanya E-commerce yang membuat aktivitas belanja menjadi semakin mudah. Berdasarkan jumlah pengunjung bulanan situs E-commerce pada kuartal IV 2020, Shopee merupakan E-commerce yang paling banyak dikunjungi oleh pengguna internet. Penelitian ini bertujuan menganalisis pengaruh rating dan online customer review terhadap keputusan pembelian di E-commerce Shopee. Sumber data menggunakan data primer yang diperoleh berdasarkan hasil pengisian kuesioner oleh responden dan data sekunder yang diperoleh melalui literasi jurnal ilmiah, buku, dan sumber bacaan lainnya. Penelitian ini dilaksanakan pada bulan juni 2022. Responden pada penelitian ini adalah mahasiswa Institut Pertanian Bogor. Teknik data yang digunakan yaitu uji validitas dan uji reliabilitas dengan metode pengolahan data yang digunakan yaitu analisis deskriptif dan SEM-PLS. Hasil penelitian menjelaskan bahwa Variabel rating berpengaruh secara positif dan signifikan terhadap variabel keputusan pembelian dan variabel customer online review berpengaruh secara positif dan signifikan terhadap keputusan pembelian., Advances in information technology have given rise to E-commerce which makes shopping activities easier. Based on the number of monthly visitors to E-commerce sites in the fourth quarter of 2020, Shopee is the most visited E-commerce by internet users. This study aims to analyze the effect of ratings and online customer reviews on purchasing decisions at E-commerce Shopee. Data sources use primary data obtained based on the results of filling out questionnaires by respondents and secondary data obtained through literacy in scientific journals, books and other reading sources. This research was conducted in June 2022. Respondents in this study were students of the Bogor Agricultural University. The data technique used is the validity test and reliability test with the data processing method used is descriptive analysis and SEM-PLS. The results of the study explain that the rating variable has a positive and significant effect on the purchasing decision variable and the online customer review variable has a positive and significant effect on the purchasing decision. Keywords: E-commerce, Online Customer Review, Rating, Purchase Decision, SEM-PLS
Keyword: E-commerce, Online Customer Review, Rating, Purchase Decision, SEM-Pls

Judul: The Influence of Online Consumer Reviews on Purchasing  Decisions on High Involvement Products with Shopee and Tokopedia marketplace  mediation in Bogor City
Abstrak: Tahun 2019-2020 (Q2) diketahui penetrasi internet di Indonesia mencapai 73,7% dengan jumlah pengguna internet 196.71 juta jiwa, angka tersebut meningkat 8,9% dari tahun 2018 dengan pertumbuhan pengguna 25.53 juta jiwa menurut APJII 2020. Data tersebut menunjukan toko offline mulai berubah menjadi toko online. Hal ini didukung oleh survei SIRCLO pada tahun 2020, platform belanja online yang paling banyak digunakan masyarakat Indonesia adalah marketplace (97% responden). Tujuan penelitian yang dilakukan adalah: mengidentifikasi karakteristik pelanggan Shopee dan Tokopedia, serta menganalisis pengaruh online consumer reviews terhadap keputusan pembelian pada high involvement products dengan mediasi lokapasar Shopee dan Tokopedia di Kota Bogor. Pada penelitian yang dilakukan digunakan teknik sampling non-probability, yaitu teknik purposive sampling dengan jumlah 100 responden yang memiliki karakteristik yang pernah berbelanja online melalui Shopee dan Tokopedia. Teknik analisis data yang digunakan adalah analisis deskriptif dan analisis Structural Equation Modeling-Partial Least Score (SEM-PLS). Hasil penelitian menunjukan terdapat dua variabel yang berpengaruh signifikan terhadap keputusan pembelian dengan mediasi Shopee dan Tokopedia yaitu, Review Valence dan Source Credibility.
Keyword: High Involvement Products, Purchase Decisions, Shopee and Tokopedia Marketplace, Online Consumer Reviews, SEM-PLS

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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