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: Online Food Delivery Application Users Research on  The Use Of Digital Nudge to Shape Responsible Consumption
Abstrak: Layanan pesan antar makanan daring di Indonesia berkembang pesat, tetapi juga berdampak pada lingkungan dan konsumsi berlebih. Sebagai upaya untuk meminimalisir dampak negatif, aplikasi online food delivery telah menerapkan strategi nudging. Di Indonesia efektivitasnya masih belum dianalisis serta masih diperlukan analisis untuk menemukan strategi nudging yang efektif. Oleh karena itu, penelitian ini mengevaluasi efektivitas digital nudge pada generasi muda usia 18-29 tahun. Penelitian ini mengeksplorasi sikap dan perilaku terkait konsumsi yang bertanggung jawab serta penggunaan digital nudge dalam aplikasi, dengan menggunakan metode kuantitatif dan kualitatif. Hasilnya menunjukkan ketidaksesuaian antara sikap dan perilaku partisipan terkait konsumsi bertanggung jawab. Faktor-faktor seperti kurangnya kesadaran terhadap keberadaan fitur, biaya tambahan, penyajian informasi yang kurang menarik, kurangnya kerjasama serta pemahaman dari pihak restoran, dan kurangnya kepercayaan terhadap transparansi alokasi dana menjadi kendala dalam mencapai efektivitas yang diharapkan., Online food delivery in Indonesia is growing rapidly, despite its impact on the environment and overconsumption. To minimize negative impacts, online food delivery apps have implemented nudging strategies. In Indonesia, its effectiveness has not been analyzed and analysis is still needed to find an effective nudging strategy. Therefore, this study evaluates the effectiveness of digital nudge among young people aged 18-29 years. This research explores attitudes and behaviors related to responsible consumption and the use of digital nudging in apps, using quantitative and qualitative methods. The results showed a mismatch between participants' attitudes and behaviors regarding responsible consumption. Factors such as lack of awareness of the features, additional costs, unattractive presentation of information, lack of cooperation and understanding on the part of restaurants, and lack of trust in the transparency of fund allocation are obstacles to achieving the expected effectiveness.
Keyword: digital nudge, efektivitas, generasi muda, konsumsi bertanggung jawab, layanan pesan antar makanan

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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