Judul: Usability Testing of Web Application for  Agroecological Assessment of Land Suitability for Garlic (INA Agro-GARLIC)
Abstrak: Permintaan bawang putih di Indonesia terus meningkat dan tidak selalu sejalan dengan produktivitasnya. Evaluasi kesesuaian lahan untuk penanaman bawang putih sangat penting dilakukan guna meningkatkan produktivitas bawang putih. Sebelumnya telah dikembangkan aplikasi web INA Agro-GARLIC untuk memudahkan penilaian agroekologi kesesuaian lahan bawang putih, namun belum dilakukan uji kebergunaan terhadap aplikasi tersebut. Penelitian ini bertujuan menguji kebergunaan INA Agro-GARLIC dengan melibatkan partisipan sebagai calon pengguna menggunakan PSSUQ (Post-Study System Usability Questionnaire) berdasarkan komponen efektivitas, efisiensi, dan kepuasan pengguna. Pengujian kebergunaan dilakukan sebanyak tiga iterasi, dengan masing masing jumlah partisipan adalah sembilan, sepuluh dan 20 partisipan. Secara keseluruhan, skor PSSUQ yang dihasilkan pada masing-masing iterasi pengujian sudah baik yaitu mendapat nilai 1.99, 1.65, dan 1.83. Selain itu, nilai rata-rata keberhasilan partisipan menyelesaikan tugas pada pengujian terakhir adalah 90%. Penelitian ini menghasilkan beberapa rekomendasi perbaikan berupa catatan dan desain untuk pengembangan selanjutnya yang didapatkan dari analisis masalah kebergunaan., The demand for garlic in Indonesia continues to rise, yet productivity doesn’t always align with this demand. Evaluating land suitability for garlic cultivation is crucial to enhance productivity. Previously a web application, INA Agro-GARLIC, was developed to facilitate the agroecological assessment of land suitability for garlic planting. However, it’s usability has not been previously tested. This research aims to evaluate the usability of INA Agro-GARLIC by involving participants as potential users, using the Post-Study System Usability Questionnaire based on effectiveness, efficiency, and user satisfaction. Usability testing was conducted in three iterations, with nine, ten, and 20 participants in each iteration. Overall, the PSSUQ from each testing iteration were satisfactory, achieving values of 1.99, 1.65, and 1.83. Additionally, the average success rate of participants in completing tasks in the last iteration of testing was 90%. This research resulted in several recommendations for further development from the analysis of usability issues.
Keyword: bawang putih, INA Agro-GARLIC, kesesuaian lahan, uji  kebergunaan, PSSUQ, garlic, land suitability, usability testing

Judul: Pengujian Aplikasi Mobile pada Penilaian Agroekologi Kesesuaian Lahan Bawang Putih (INA AgroGARLIC) dengan Usability Testing
Abstrak: Bawang putih (Allium sativum L) merupakan jenis sayuran yang paling sering dikonsumsi oleh masyarakat Indonesia. Sayangnya, produktivitas bawang putih domestik semakin menurun ketika bawang putih impor dari China mulai masuk ke Indonesia. Saat ini pemerintah sedang berusaha untuk meningkatkan produktivitas bawang putih. Untuk membantu upaya tersebut dibentuklah Sistem Pendukung Keputusan Spasial dalam bentuk aplikasi mobile berbasis Android dengan nama INA Agro-GARLIC. Aplikasi tersebut dapat melihat kesesuaian lahan untuk ditanami bawang putih. Pada pengembangan iterasi pertama dan keduanya INA Agro-GARLIC belum melalui tahapan tes non-fungsional. Penelitian ini dilakukan dengan metode Usability Testing dan kuesioner PSSUQ (Post Study System Usability Questionnaire). Tujuan uji kebergunaan dari aplikasi ini supaya nantinya pengguna merasa terbantu dan tidak ragu untuk melakukan adopsi teknologi dengan memanfaatkan INA Agro-GARLIC. Hasil penelitian ini berupa rekomendasi perbaikan system. Rekomendasi yang diberikan yaitu memperbaiki beberapa desain tombol, diskusi kembali dengan pakar terkait penggunaan istilah dan memberikan beberapa tambahan fitur., Garlic (Allium sativum L) is the type of vegetable most often consumed by Indonesian people. Unfortunately, domestic garlic productivity continues to decline when imported garlic from China begins to enter Indonesia. Currently the government is trying to increase garlic productivity. To assist these efforts, a Spatial Decision Support System was formed in the form of an Android-based mobile application with the name INA Agro-GARLIC. This application can see the suitability of the land for planting garlic. In the development of the first and second iterations, INA Agro-GARLIC has not yet gone through the non-functional testing stage. This research was conducted using the Usability Testing method and the PSSUQ (Post Study System Usability Questionnaire) questionnaire. The aim of testing the usability of this application is so that later users will feel helped and will not hesitate to adopt technology by utilizing INA Agro-GARLIC. The results of this research are recommendations for system improvements. The recommendations given are to improve several button designs, discussing again with experts regarding the use of terms and providing several additional features.
Keyword: garlic, mobile application, PSSUQ, usability testing

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.
Keyword: