Judul: The Relationship between Electronic Word of Mouth Communication and the Purchase Decision of Vegetable Products through Instagram Segari
Abstrak: Pandemi yang sebelumnya melanda Indonesia, mengakibatkan keterbatasan mobilititas masyarakat yang mengubah aktivitas masyarakat menjadi serba daring. Salah satu aktivitas yang mengalami perubahan tersebut yaitu aktivitas jual beli. Pertimbangan konsumen dalam belanja online dapat dilakukan salah satunya melalui ulasan yang ditulis melalui media internet atau yang dikenal dengan Electronic word of mouth. Electronic word of mouth dapat mendorong keputusan pembelian konsumen produk sayuran melalui e-commerce. Penelitian ini bertujuan untuk menganalisis hubungan penyebaran informasi melalui komunikasi electronic word of mouth dengan keputusan pembelian produk sayuran melalui media sosial instagram segari. Metode yang digunakan adalah metode penelitian survei dengan pendekatan kuantitatif menggunakan kuesioner yang didukung dengan data kualitatif berupa wawancara mendalam. Teknik pemilihan responden dilakukan dengan purposive sampling diambil dari pengikut instagram @Segari.id dan sudah pernah membeli produk sayuran Segari sebanyak 140 orang. Hasil penelitian menunjukkan bahwa dimensi electronic word of mouth yaitu, intensitas penggunaan media sosial instagram Segari dan isi informasi memiliki hubungan dengan keputusan pembelian., The pandemic that previously hit Indonesia resulted in limited community mobility which turned people's activities completely online. One of the activities that has experienced these changes is buying and selling activities. Consumer considerations in online shopping can be done one of them through reviews written through internet media or what is known as electronic word of mouth. Electronic word of mouth can encourage consumer purchasing decisions for vegetable products through e-commerce. This study aims to analyze the relationship between the dissemination of information through electronic word of mouth communication and the purchase decision of vegetable products through Instagram Segari social media. The method used is a survey research method with a quantitative approach using a questionnaire supported by qualitative data in the form of in-depth interviews. The respondent selection technique was carried out by purposive sampling taken from Instagram followers @Segari.id and 140 people who had bought Segari vegetable products. The results of the study show that the dimensions of electronic word of mouth, namely the intensity of social media instagram Segari use and information content, have a relationship with purchasing decisions.
Keyword: Electronic word of mouth, Instagram, Keputusan pembelian

Judul: Pengaruh Electronic Word of Mouth (eWOM) Terhadap Keputusan Pembelian Produk Esteh Indonesia
Abstrak: Sebelum melakukan pembelian produk makanan/minuman, konsumen sekarang ini cenderung akan mencari ulasan/review secara online terlebih dahulu, salah satunya melalui autobase @FOODFESS2. Kehadiran autobase @FOODFESS2 di Twitter memudahkan konsumen dalam mencari review produk makanan/minuman termasuk produk Esteh Indonesia. Electronic word of mouth (eWOM) yang dilakukan followers autobase tersebut diduga mampu memengaruhi keputusan pembelian terhadap produk Esteh Indonesia. Penelitian ini bertujuan untuk menganalisis pengaruh electronic word of mouth (eWOM) terhadap keputusan pembelian produk Esteh Indonesia. Analisis data menggunakan analisis deskriptif dan analisis SEM-PLS. Hasil analisis SEM-PLS menunjukkan bahwa dimensi expressing positive feelings berpengaruh signifikan terhadap keputusan pembelian produk Esteh Indonesia. Sedangkan dimensi platform asistance, concern for other customer, venting negative feelings, dan advice seeking tidak berpengaruh signifikan terhadap keputusan pembelian produk Esteh Indonesia. Berdasarkan hasil penelitian ini, disarankan kepada Esteh Indonesia untuk konsisten dalam meningkatkan kualitas produk, peningkatan layanan konsumen, terus mengajak konsumen untuk membagikan pengalaman positifnya, dan mengumpulkan testimoni pelanggan agar konsumen mau membagikan pengalaman positifnya terhadap Esteh Indonesia
Keyword: autobase, eWOM, keputusan pembelian, SEM-PLS, twitter

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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