Judul: User Research on E-Commerce Application Regarding The Use of Digital Nudge to Form Responsible Consumption
Abstrak: Teknologi informasi yang semakin kompleks telah memicu pertumbuhan e-commerce dengan pengaruh besar pada kehidupan manusia. E-commerce telah meningkat seiring dengan perkembangan internet yang meluas. Pandemi COVID-19 mempercepat pertumbuhan e-commerce di Indonesia sebagai respons terhadap kebutuhan untuk menghindari kontak fisik. Strategi nudging diperlukan untuk mendorong konsumsi bertanggung jawab yang sejalan dengan Sustainable Development Goals (SDGs) Nomor 12. Penelitian ini berfokus pada sikap dan perilaku serta efektifitas digital nudge pengguna usia 18-35 tahun melalui tahapan persiapan instrumen, rekrutmen partisipan, uji pengguna, wawancara, pengisian kuesioner, analisis hasil, dan dokumentasi desain. Hasil yang diperoleh terdapat ketidaksesuaian antara sikap dan perilaku. Partisipan memiliki pemahaman dan sikap yang baik terhadap fitur seperti donasi. Namun, perilaku belum mencerminkan hal tersebut dikarenakan alasan seperti ketidakjelasan informasi dan tujuan, biaya, dan ketidaktahuan. Selain itu, fitur rating serta kesulitan menerapkan kemasan yang ramah lingkungan juga menjadi perhatian., The increasingly complex information technology has led to the growth of e-commerce, significantly impacting human lives. E-commerce has grown alongside the widespread development of the Internet. The COVID-19 pandemic has sped up e-commerce growth in Indonesia as a response to the need to avoid physical contact. Nudging strategies are needed to encourage responsible consumption in line with Sustainable Development Goals (SDGs) Number 12. This research focuses on the attitudes and behaviors, as well as the effectiveness of digital nudges for users aged 18-35, through stages including instrument preparation, participant recruitment, user testing, interviews, questionnaire completion, result analysis, and design documentation. The results show a mismatch between attitudes and behaviors. Participants have good understanding and positive attitudes towards features like donations. But, their behaviors don't reflect this due to reasons like unclear information and objectives, costs, and lack of awareness. Additionally, features like rating and the difficulty in implementing eco-friendly packaging are also concerns.
Keyword: digital nudge, e-commerce, konsumsi bertanggung jawab, responsible consumption

Judul: Research on the Use of Digital Nudges to Form Responsible Consumption Habits for Online Groceries App Users
Abstrak: Permasalahan meningkat akibat konsumsi bahan makanan yang tidak bertanggung jawab. Sekitar 12% total sampah nasional terdiri dari sampah kertas/karton/kardus, setara dengan 4,14 juta ton/tahun, hanya sekitar 66,47% yang dikelola baik. Mencerminkan konsumsi yang tidak melihat dampak terhadap lingkungan. Perubahan ini mempengaruhi sikap dan perilaku, ditambah hadirnya online groceries. Solusi yang diharapkan menggunakan digital nudge. Penelitian ini bertujuan mengevaluasi efektivitas sikap dan perilaku generasi muda terhadap konsumsi bertanggung jawab. Metode melibatkan persiapan instrumen, rekrutmen partisipan, uji pengguna, wawancara, pengisian kuesioner, analisis hasil dan dokumentasi desain. Hanya 4 dari 22 responden menggunakan fitur nudge. Hasil uji menunjukkan perbedaan antara pemahaman dan sikap dengan perilaku. Mayoritas pengguna mengetahui adanya fitur nudge ini karena minimnya kesadaran akan isu lingkungan, penyajian informasi yang kurang menarik, dan frekuensi berbelanja yang tidak terlalu sering., The problem increases due to irresponsible consumption of foodstuffs. About 12% of the total national waste consists of paper/cardboard/cardboard waste, equivalent to 4.14 million tons/year, only about 66.47% of which is managed properly. Reflecting consumption that does not see the impact on the environment. These changes affect attitudes and behaviors, plus the presence of online groceries. The expected solution is to use digital nudge. This study aims to evaluate the effectiveness of young people's attitudes and behaviors towards responsible consumption. Methods involved instrument preparation, participant recruitment, user testing, interviews, questionnaire completion, result analysis and design documentation. Only 4 out of 22 respondents used the nudge feature. The test results showed a difference between understanding and attitude and behavior. The majority of users are aware of the nudge feature due to the lack of awareness of environmental issues, the presentation of information that is less interesting, and the frequency of shopping that is not too frequent.
Keyword: digital nudge, Konsumsi yang bertanggung jawab, online groceries (sayubox), pengguna aplikasi

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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