Judul: Analisis Efektivitas Promosi Somethinc dengan Attention, Interest, Search, Action, Share (AISAS) Model
Abstrak: Pertumbuhan industri kosmetik lokal di Indonesia mengalami peningkatan sehingga persaingan dalam meningkatkan penjualan antar perusahaan kosmetik lokal semakin tinggi. Perusahaan membuat strategi untuk dapat bertahan pada pasar dengan menggunakan social media marketing. Penelitian ini bertujuan untuk menganalisis efektivitas promosi Somethinc dengan attention, interest, search, action, dan share (AISAS) model serta mengidentifikasi karakteristik konsumen Somethinc. Penelitian ini menggunakan 185 responden yang berdomisili di wilayah Jabodetabek. Teknik penentuan sampel menggunakan metode non-probability sampling jenis quota sampling. Metode analisis pada penelitian ini adalah analisis deskriptif dan Structural Equation Modelling Partial Least Square (SEM PLS). Hasil penelitian ini menyatakan bahwa variabel social media marketing berpengaruh signifikan terhadap attention, interest, dan keinginan seseorang untuk mencari tahu lebih banyak tentang informasi yang dipromosikan. Variabel attention, interest, search berpengaruh signifikan terhadap keputusan pembelian, serta aktivitas pembelian konsumen memengaruhi keinginan konsumen dalam membagikan pengalaman., The growth of the local cosmetic industry in Indonesia has increased, the competition between local cosmetic companies to increase sales is getting higher. The company has a strategy to survive in the market by using social media marketing. This study aims to analyze the effectiveness of Something product promotion using the attention, interest, search, action, and share (AISAS) model and identify the characteristics of consumers of Somethinc. This study used 185 respondents who live in Jabodetabek. The sampling technique was non-probability sampling method of quota sampling. The methods of analysis in this study were descriptive analysis and Structural Equation Modeling Partial Least Square (SEM-PLS). The results of this study state that social media marketing variables show a significant effect on attention, interest, and desire to discover more about the information being promoted. The attention, interest, and search variables show a significant effect on purchase decision, and consumer purchasing activities influence their desire to share their experiences.
Keyword: AISAS model, social media, SEM-PLS, social media marketing, Somethinc

Judul: Pengaruh Electronic Word of Mouth dan Brand Image terhadap Keputusan Pembelian Kosmetik Somethinc pada E-Commerce di Jabodetabek
Abstrak: Kebutuhan akan produk kosmetik berakibat pada tinginya pengguna kosmetik di Jabodetabek. Pada tahun 2022 preferensi merek lokal mencapai 54%. Somethinc sebagai salah satu merek kosmetik lokal menduduki peringkat keempat sebagai kosmetik dengan pengguna terbanyak pada 2022. Meningkatnya pengguna internet di Indonesia dimanfaatkan juga untuk melakukan jual beli dengan memanfaatkan e-commerce. E-commerce sendiri menjadi media pembelian kosmetik terbesar pada 2022. Namun penjualan Somethinc tidak menentu dan industri kosmetik yang bertambah meningkatkan persaingan. Sehingga diperlukan strategi untuk meningkatkan penjualan. Penelitian ini bertujuan untuk menganalisis electronic word of mouth dan brand image terhadap keputusan pembelian kosmetik Somethinc pada e-commerce di Jabodetabek. Penelitian ini menggunakan data primer dengan menyebar kuesioner dan data sekunder yang bersumber dari buku, jurnal, dll. Metode penarikan sampel menggunakan teknik quota sampling dan diolah menggunakan metode analisis deskriptif dan SEM-PLS. Hasil penelitian menunjukkan adanya pengaruh yang positif dan signifikan antara electronic word of mouth dan brand image terhadap keputusan pembelian produk kosmetik Somethinc pada e-commerce di Jabodetabek., The need for cosmetic products results in a high number of cosmetic users in Jabodetabek. In 2022, the preference for local brands reached 54%. Somethinc as one of the local cosmetic brands is ranked fourth as the cosmetic with the most users in 2022. The increasing number of internet users in Indonesia is also used to buy and sell by utilizing e-commerce. E-commerce itself will be the largest medium for purchasing cosmetics in 2022. However, Somethinc's sales are erratic and the growing cosmetics industry increases competition. Therefore a strategy is needed to increase sales. This study aims to analyze electronic word of mouth and brand image on purchasing decisions for Somethinc cosmetics in e-commerce in Jabodetabek. This study uses primary data by distributing questionnaires and secondary data sourced from books, journals, etc. The sampling method uses quota sampling technique and is processed using descriptive analysis method and SEMPLS. The results showed a positive and significant influence between electronic word of mouth and brand image on purchasing decisions for Somethinc cosmetic products in e-commerce in Jabodetabek.
Keyword: brand image, e-commerce, electronic word of mouth, purchase decision

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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