Judul: Development of Backend Module on Garlic Land Suitability Spatial Decision Support System
Abstrak: Bawang putih merupakan salah satu komoditas hortikultura yang memiliki beragam manfaat dan banyak dikonsumsi. Permasalahan dalam meningkatkan produksi bawang putih bermutu adalah sulitnya menentukan lahan yang sesuai, karena bawang putih tidak dapat tumbuh di sembarang tempat. Lahan yang tidak sesuai mengakibatkan pertumbuhan tanaman bawang putih tidak optimal sehingga menurunkan angka produktivitas bawang putih. Penelitian ini bertujuan untuk pengembangan modul backend dari sistem pendukung keputusan spasial sebagai inovasi teknologi untuk mengevaluasi kesesuaian lahan serta menampilkan visualisasi data hasil evaluasi dalam bentuk gambar atau peta. Sistem dikembangkan dengan menggunakan framework Express.js dan basis data PostgreSQL dalam pembuatan REST API, serta metode Prototyping sebagai metode pengembangannya. Penelitian ini mengembangkan module backend untuk penentuan penanaman lahan bawang putih yang telah menghasilkan 12 URI API dan 1 scheduler yang telah berhasil diuji dengan menggunakan metode blackbox testing, Garlic is one of the horticultural commodities that has various benefits and widely consumed. The problem faced when you want to increase the production of qualified garlic is the difficulty of determining the appropriate land, because garlic cannot just grow anywhere. The inappropriateness of the land used will result in the suboptimal growth of garlic plants and reducing the productivity. This study focuses on the development of the backend module of a spatial decision support system as a technological innovation to evaluate the suitability of garlic land and display the visualization of the evaluation data in images or maps. The system is developed using the Express.js framework and PostgreSQL database in making the REST API, and also the Prototyping method as the development method. This study develops a backend module for determining garlic plantations which has produced 12 API URIs and 1 scheduler that has been successfully tested using the blackbox testing method
Keyword: backend, garlic, land suitability evaluation, REST API, spatial decision support system

Judul: Pengembangan Fitur pada Modul Backend Sistem Pendukung Keputusan Spasial Kesesuaian Lahan Bawang Putih
Abstrak: Permasalahan dalam meningkatkan produktivitas bawang putih adalah sulitnya menentukan lahan yang sesuai. Penelitian sebelumnya telah berhasil mengembangkan modul backend sistem pendukung keputusan spasial untuk melakukan evaluasi kesesuaian lahan bawang putih. Penelitian ini bertujuan untuk melakukan pengembangan dari modul backend pada penelitian sebelumnya. Pengembangan tersebut di antaranya melakukan pembatasan akses pada fitur penilaian kesesuaian lahan, membuat fitur-fitur yang bergantung dengan fungsi penyimpanan fail dapat digunakan, membuat data lokasi lahan pengguna dapat ditampilkan pada peta, memperbaiki penentuan titik tengah data satuan peta tanah (SPT), dan mendapatkan data lama penyinaran terbaru secara otomatis untuk daerah SPT pada data kesesuaian lahan. Tahapan pada penelitian ini yaitu identifikasi dan analisis kebutuhan, pemodelan modul backend, pengembangan modul backend, serta pengujian dan pengunggahan modul backend. Pengembangan menghasilkan 16 tabel baru yang telah dinormalisasi pada basis data. Kemudian, dihasilkan 37 Application Programming Interface baru dan 1 scheduler baru yang telah berhasil diunggah ulang dan diuji., The problem in increasing garlic productivity is the difficulty of determining suitable land. Previous study has succeeded in developing a spatial decision support system backend module to evaluate garlic land suitability. This study aims to improve the backend module developed in the previous study. These developments include restricting access to the land suitability assessment feature, making features that depend on the file storage function usable, making user-entered field location data can be shown on the map, fixing soil map unit (SMU) data midpoint determination, and getting the latest length of irradiation data automatically for SMU area on land suitability data. The stages in this study are identification and analysis of needs, backend module modeling, backend module development, and backend module testing and deployment. Development generates 16 new tables that have been normalized in the database. This study results 37 new Application Programming Interfaces and 1 new scheduler which have been successfully re-uploaded and tested.
Keyword: backend, garlic, garlic productivity, land suitability, spatial decision support system

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: