Judul: Design an Android Based Shallot Distribution Traceability System Using QR Code
Abstrak: Tingginya jumlah produksi bawang merah di Indonesia tidak diiringi dengan informasi yang jelas mengenai asal-usul produk selama proses distribusi. Asal-usul di sini mencakup penanaman, kualitas, jumlah, harga, penanganan yang dilakukan, dan pelaku yang bertanggung jawab selama proses distribusi sampai ke tahap akhir rantai pasok. Oleh karena itu sistem ketertelusuran (traceability) menjadi hal penting untuk dikembangkan untuk memperoleh informasi asal-usul yang jelas dari suatu produk. Penelitian ini bertujuan mengidentifikasi rantai pasok distribusi bawang merah dan membuat rancang bangun sistem ketertelusuran distribusi berbasis android dengan implementasi Quick Response (QR) Code. Metode yang digunakan dalam penelitian ini adalah System Development Life Cycle (SDLC) model waterfall. Hasil penelitian menunjukkan bahwa rantai pasok bawang merah dimulai dari petani, perantara, pedagang pengepul, pasar induk, pengecer, dan konsumen rumah tangga. Penelitian juga menghasilkan aplikasi android bernama Shobis yang dibangun menggunakan bahasa Kotlin dan layanan Firebase. Seluruh data ketertelusuran disimpan menggunakan kode unik berupa QR Code. Sistem ketertelusuran yang dibangun dapat dikelola oleh kementrian perdagangan, e-commerce, dan konsumen industri seperti UMKM. Biaya yang diperlukan untuk menjalankan sistem ini dibagi menjadi dua yaitu biaya yang dikeluarkan aktor dan organisasi meliputi biaya tetap serta biaya tidak tetap. Pengujian sistem dilakukan untuk mengetahui seluruh sistem berfungsi dengan baik. Pemeliharaan juga dilakukan untuk mengevaluasi sistem yang telah dibangun. Evaluasi dilakukan menggunakan metode System Usability Scale (SUS) dan memperoleh skor 70,48 serta percentile rank 56%., The high amount of shallot production in Indonesia is not accompanied by clear information on the origin of the product during the distribution process. This includes planting, quality, quantity, price, handling, and responsible actors during the distribution process to the final stage of the supply chain. Therefore, it is important to develop a traceability system to obtain clear information on the origin of a product. This research aims to identify the shallot distribution supply chain and design an Android-based distribution traceability system with Quick Response (QR) Code implementation. The method used in this research is the System Development Life Cycle (SDLC) waterfall model. The results showed that the shallot supply chain starts from farmers, intermediaries, collecting traders, wholesale markets, retailers, and household consumers. The research also produced an Android application called Shobis which was built using the Kotlin language and Firebase services. All traceability data is stored using a unique code in the form of a QR Code. The traceability system can be managed by the Ministry of Trade, e-commerce, and industrial consumers such as MSMEs. The costs required to run this system are divided into 2 namely, costs incurred by actors and organizations, including fixed and non-fixed costs. System testing is conducted to determine if the entire system is functioning properly. Maintenance is also carried out to evaluate the system that has been built. The evaluation was carried out using the System Usability Scale (SUS) method and obtained a score of 70.48 and a percentile rank of 56%.
Keyword: android, QR Code, SDLC, shallot, traceability

Judul: Front-End Development of Blockchain Based Shallot Supply Chain System Using Prototyping Method
Abstrak: Bawang merah (Allium ascalonicum L.) merupakan komoditas hortikultura yang memiliki angka konsumsi rumah tangga tertinggi di Indonesia. Untuk menjaga kualitas dan keamanan produk maka diperlukan pemantauan pada kualitas produk pada rantai pasok bawang merah yang dimulai dari panen benih oleh penangkar hingga sampai ke tangan konsumen. Blockchain sebagai buku besar transaksi, dapat dimanfaatkan untuk melakukan pencatatan transaksi dan penelusuran transaksi pada rantai pasok. Penelitian ini bertujuan untuk mengembangkan aplikasi front-end pada sistem rantai pasok bawang merah berbasis blockchain menggunakan library ReactJS dan REST API untuk komunikasi data. Pengembangan sistem ini dilakukan secara tim dan menggunakan metode Prototyping. Hasil dari penelitian ini merupakan progressive web app yang dapat mencatat transaksi penangkar, petani, dan pengumpul pada rantai pasok dan dapat membantu konsumen dalam melakukan penelusuran pada komoditas bawang merah yang telah diuji menggunakan metode black-box. Diharapkan pada penelitian selanjutnya dapat dilakukan penelitian pada aspek user experience pada aktor rantai pasok., Shallot (Allium ascalonicum L.) is a horticultural commodity that has the highest household consumption rate in Indonesia. To maintain the quality and safety of the product, it is necessary to monitor product quality in the shallot supply chain, starting from seed harvesting by breeders to the hands of consumers. Blockchain as a transaction ledger can be used to record and trace transactions in the supply chain. This study aims to develop a front-end on the shallot supply chain blockchain system using the React JS library and REST API for data communication. The development of this system is carried out in a team using the Prototyping method. The results of this study are progressive web app that can record the transactions of shallot breeders, farmes, and collectors in the supply chain and enables consumers to conduct searches on the shallot commodity that have been tested using black-box method. It is hoped that further studies can conduct researchs on the user experience aspect of supply chain actors.
Keyword: blockchain, front-end, prototyping, shallots, supply chain

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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