Judul: Factors Affecting Vegetables Repurchase Intention on E-commerce Using C-TAM-TPB Model Approach
Abstrak: Digitalisasi ekonomi telah membawa inovasi terhadap pemasaran produk pertanian termasuk komoditas sayuran sehingga kini sayur dapat dijual secara online di e-commerce. Namun, selama setengah tahun pertama 2022 telah terjadi penurunan persentase adopsi online groceries termasuk sayur pada masyarakat SEA dari 64 persen menjadi 3 persen dibanding tahun 2021. Hal ini mengindikasikan adanya kemungkinan penurunan minat konsumen untuk kembali membeli produk tersebut. Oleh karena itu, penting untuk melakukan sebuah studi guna memahami karakteristik konsumen saat ini dan menganalisis faktor-faktor yang dapat mendorong konsumen untuk membeli sayur di e-commerce secara berulang. Penelitian ini melibatkan 180 responden dan digunakan analsis deskriptif untuk mendeskripsikan karakteristik responden serta digunakanan analisis SEMPLS untuk menganalisis faktor-faktor yang memengaruhi intensi pembelian ulang sayur di e-commerce menggunakan pendekatan Model C-TAM-TPB. Diketahui bahwa mayoritas konsumen berasal dari kalangan mahasiswa/pelajar yang melakukan pembelian kurang dari tiga kali dalam sebulan. Terdapat tiga faktor yang berpengaruh positif signifikan secara langsung kepada intensi pembelian ulang sayur di e-commerce, yaitu sikap, norma subjektif, dan persepsi kontrol perilaku. Sementara secara tidak langsung juga terdapat tiga faktor yang berpengaruh positif signifikan terhadap intensi pembelian ulang sayur di ecommerce, yaitu persepsi kegunaan, persepsi kemudahan penggunaan, dan pengalaman konsumen., Economic digitalization has brought innovation to the marketing of agricultural products including vegetable commodities so that now vegetables can be sold online via e-commerce. However, during the first half of 2022 there has been a decline in the percentage of adoption of online groceries including vegetables in SEA communities from 64 percent to 3 percent compared to 2021. This indicates a possible decline in consumer interest in purchasing vegetables again. Therefore, it is important to conduct a study to understand the characteristics of current consumers and analyze the factors that may encourage consumers to purchase vegetables through e-commerce on a recurring basis. This study involved 180 respondents and used descriptive analysis to describe the characteristics of respondents and SEM-PLS analysis to analyze the factors that influence the intention to repurchase vegetables through e-commerce based on the C-TAM-TPB model. It is known that the majority of consumers are students who make purchases less than three times a month. There are three factors that have a significant positive effect directly on the intention to repurchase vegetables through e-commerce, namely attitudes, subjective norms, and perceived behavioral control. While indirectly there are also three factors that have a significant positive effect on the intention to repurchase vegetables through e-commerce, namely perceived usefulness, perceived ease of use, and consumer experience.
Keyword: C-TAM-TPB, e-commerce, intensi pembelian ulang, pengalaman konsumen, SEM-PLS

Judul: The Effect of New Normal Situation on Intention and Behavior to Purchase Vegetables Through Agricultural E-commerce
Abstrak: Tren peningkatan penetrasi internet di Indonesia dimanfaatkan masyarakat untuk melakukan transaksi bisnis secara daring melalui e-commerce pertanian. Situasi new normal di Indonesia tetap menjadi faktor penting keputusan pembelian sayuran secara online. E-commerce pertanian digunakan masyarakat untuk memenuhi kebutuhan sehari-hari dalam membeli produk sayuran. Penelitian ini bertujuan untuk menganalisis sikap, norma subjektif, kontrol perilaku, dan situasi new normal terhadap niat dan perilaku pembelian sayuran melalui e-commerce pertanian. Penelitian ini menggunakan data primer melalui penyebaran kuesioner secara daring dengan jumlah 130 responden. Metode yang digunakan dalam penelitian ini adalah analisis deskriptif dan Structural Equation Model-Partial Least Square (SEM-PLS). Hasil penelitian ini menunjukkan bahwa konsumen sayuran e-commerce pertanian adalah perempuan muda yang mandiri dan menyukai belanja sayuran di Sayurbox, HappyFresh, Segari, TukangSayur.id, dan Astro. Variabel sikap dan situasi berpengaruh signifikan terhadap niat pembelian sayuran dan kontrol perilaku berpengaruh signifikan secara langsung terhadap perilaku pembelian sayuran melalui e-commerce pertanian., An increasing trend of increasing internet penetration which is used by the public to conduct business transaction through agricultural e-commerce. New normal situation in Indonesia remains an important factor in online purchasing decisions for vegetables. Agricultural e-commerce is used by the community to provide their daily needs in buying vegetable products. This study aims to analyze planned behavior attitudes, subjective norms, behavioral control, and situation on vegetable purchase intentions and behavior through agricultural e-commerce. This study uses primary data through online questionnaires with a total of 130 respondents. The method used in this research is descriptive analysis and Structural Equation Model-Partial Least Square (SEM-PLS). The results of this study indicate that consumers of vegetables through agricultural e-commerce is an independent young woman who loves shopping for vegetables at Sayurbox, HappyFresh, Segari, TukangSayur.id, and Astro. Attitude and situation variables have a significant effect on the intention to buy vegetables and behavioral control has a significant direct effect on the decision to buy vegetables through agricultural e-commerce.
Keyword: e-commerce, perilaku pembelian, 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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