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: Development of Frontend Module on Spatial Decision Support System for Garlic Land Suitability
Abstrak: Permasalahan dalam pengembangan lahan tanaman bawang putih adalah kurang sempurnanya pertumbuhan bawang putih yang disebabkan oleh tidak sesuainya lahan yang ditanami bawang putih. Penelitian sebelumnya telah mengembangkan sistem pendukung keputusan spasial yang dapat digunakan untuk mengevaluasi kesesuaian lahan bawang putih. Penelitian ini bertujuan untuk memperbarui tampilan pada penelitian sebelumnya dan menambahkan beberapa fitur yang dapat memberikan informasi mengenai kesesuaian lahan bawang putih. Visualisasi peta menggunakan ArcGIS yang terintegrasi dengan API dengan menggunakan framework Next.js dan TailwindCSS dengan metode prototyping sebagai metode pengembangan. Fitur utama yang ada pada sistem berupa fitur yang dapat diakses oleh publik yaitu peta kesesuaian lahan, penilaian kesesuaian lahan, about dan glosarium. Fitur pendukung yang ada pada sistem berupa fitur yang memiliki akses terbatas yaitu unduh berkas data kesesuaian lahan dan memasukkan berkas. Berdasarkan hasil dari pengujian yang dilakukan menggunakan metode blackbox testing, fitur utama dan fitur pendukung mampu berjalan dengan baik., The problem in developing garlic plantations is the incomplete growth of garlic caused by the inappropriateness of the land planted with garlic. Previous research has developed a spatial decision support system that can be used to develop garlic fields. This study aims to update the appearance of previous studies and add some features that can provide information about the availability of garlic fields. Map visualization using ArcGIS which is integrated with the API using the Next.js framework and TailwindCSS with the prototyping method as the development method. The main features in the system are features that can be accessed by the public, namely land maps, land suitability evaluation, about and a glossary. Supporting features available on the system are features that have limited access, namely downloading land suitability data files and input files. Based on the results of the tests carried out using the blackbox testing method, the main features and supporting features are able to run well.
Keyword: ArcGIS, Garlic, Land suitability, Prototyping, 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.
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