Judul: Estimation of Sugarcane (Saccharum officinarum L.) Productivity in the ENSO Phase using Crop Simulation Model
Abstrak: Indeks kejadian ENSO menurunkan setidaknya 22% jumlah produktivitas tanaman tebu. Produktivitas tebu memiliki potensi yang lebih tinggi pada tahun normal dibandingkan dengan tahun kejadian El Nino dan La Nina. Konsumsi gula nasional tahun 2013 mencapai 3 juta ton/ha. Penelitian ini bertujuan untuk menyusun model simulasi pertumbuhan, perkembangan, dan submodel neraca air tanaman tebu untuk memperkirakan produktivitas dan kebutuhan air tanaman tebu pada tiga tahun kejadian yang berbeda (El Nino, La Nina, dan tahun normal), serta menjelaskan pengaruh variabilitas iklim seperti ENSO (El Nino Southern Oscillation) terhadap produktivitas tanaman tebu. Produktivitas tanaman tebu hasil dugaan model memiliki perbedaan dengan nilai produktivitas hasil observasi dengan nilai R2 sebesar 0,99, sedangkan nilai galatnya sebesar 2,58 % pada tahun kejadian El Nino (2015 dan 2019), 2,67% pada tahun kejadian La Nina (2010 dan 2011), dan sebesar 0,19% pada tahun normal (2013 dan 2014). Kebutuhan air tanaman tebu berkisar antara 46 – 116 mm/bulan dalam sekali masa tanam., The ENSO event index reduces the total productivity of sugarcane plants by at least 22%. Sugarcane productivity has a higher potential in normal years compared to El Nino and La Nina years. National sugar consumption in 2013 reached 3 ton/ha. This study aims to develop a simulation model for sugarcane growth, development, and water balance sub-models to estimate sugarcane productivity and water demand in three different incident years (El Nino, La Nina, and normal years), as well as to explain the effects of climate variability such as ENSO (El Nino Southern Oscillation) on sugarcane productivity. The productivity of sugarcane plants as a result of the alleged model has a difference with the observed productivity value with an R2 value of 0,99, while the error value is 2,58% in El Nino years (2015 and 2019), 2,67% in La Nina years (2010 and 2011), and by 0,19% in normal years (2013 and 2014). Sugarcane water needs range from 46 – 116 mm/month in one planting period.
Keyword: tebu, model simulasi, produktivitas, kebutuhan air, ENSO

Judul: Mode simulasi dinamika nitrogen dan penentuan total kebutuhan nitrogen pada tanaman tebu (saccharum officinarum L)
Abstrak: Gula yang berasal dari tanaman tebu (Saccharum Officinarum L.) merupakan sumber pemanis utama di dunia, karena hampir 70% gula atau pemanis berasal dari tebu. Indonesia dengan jumlah penduduk terbesar keempat di dunia memiliki tingkat konsumsi gula yang sangat tinggi. Oleh karena itu, untuk menghasilkan produktifitas tebu yang optimum maka perlu mengetahui dinamika nitrogen dan efisiensi pemberian pupuk N pada tanaman tebu. Tujuan penelitian ini adalah membuat model simulasi dinamika nitrogen serta mengetahui kebutuhan nitrogen untuk penentuan jadwal pemupukan tanaman tebu di Kabupaten Cinta Manis, Sumatera Selatan berdasarkan aspek agroklimat. Pendekatan yang dilakukan adalah pengamatan sifat fisik tanah dan penyusunan simulasi model tanaman berdasarkan parameter tanah dan iklim. Hasil model dinamika nitrogen menunjukkan kebutuhan nitrogen optimum memerlukan penambahan pupuk pada tahun 2014-2015 sebesar 135 kg/ha sebelum hari ke 24 pada fase-1, tahun 2015-2016 sebesar 129 kg/ha sebelum hari ke 24 pada fase-1, dan tahun 2016-2017 harus dilakukan penambahan pupuk nitrogen sebesar 107 kg/ha sebelum hari ke 23 pada fase ke-1. Hasil produktifitas biomassa tebu sebesar 89968 kg/ha pada tahun 2014-2015, 88332 kg/ha tahun 2015-2016, dan 84919 kg/ha tahun 2016-2017. Hal ini menunjukkan bahwa model hasil simulasi dapat mendukung peningkatan produktivitas tebu untuk mendukung target swasembada gula dalam pemenuhan kebutuhan pangan.
Keyword: efisiensi, model, nitrogen, pemupukan

Judul: Algorithm Construction of HLI Hash Function
Abstrak: Cryptography is a study of mathematical techniques related to aspects of information security regarding on confidentiality, data integrity, entity authentication, and data origin authentication. Data integrity is a service, which is associated with the conversion of data carried out by unauthorized parties. To maintain data integrity, one can use hash functions. An hash function is a computationally efficient function to map an arbitrary length bitstring to a fixed length bitstring called as hash value. The use of hash function in maintaining the information integrity and authentication is in digital signatures, virus protection, and software distribution. Illustration of the hash function in the integrity and authentication of information that is emailed as follow. The sender sends the information and hash value to the recipient. If the hash value of the information is equal to the hash value that is sent by the sender, then information has not been changed. Otherwise the information has been changed. An hash function has two properties, one way and collision resistance. An hash function is called one way if it is computationally infeasible to find any input such that when given any hash value . Meanwhile an hash function is called collision resistant if it is computationally infeasible to find any two inputs where such that . The purpose of this study is to construct a HLI hash function algorithm, to analyze the speed and security of the hash functions as a results of construction. Furthermore, it is to compare it with SWIFFT. Hash function is constructed based on the result of algebraic operations on modular polynomial ringwith . Modular polynomial ring noted as is a set of all polynomials of degree at most with coefficients in . can be represented as a set of integer vector of modulo in dimension . So, it is simple to implement in a computer. In vector operations, is lattice . Furthermore, alattice that is defined from certain polynomial ring is called ideal lattice. HLI hash function is consists of addition and multiplication algorithm in the ring. Addition algorithm consists of sumation operations of modulo and multiplication consists of multiplication operations of modulo . Generally, algorithm of HLI hash function consists of multiplication operations of modulo and addition operations of modulo . However, if the input is binary number then multiplication algorithm only consists of multiplication operation of modulo , so algorithm of HLI hash function consists of multiplication operations of modulo and addtion operations of modulo . An hash function is secured if it has two properties, i.e., one way and collision resistance. HLI hash function hash is one way, it is following the proof of Micciancio. It is has collision resistant because of polynomial is irreducible over and monic. Moreover, it is proved that for every unit vector , the vector is small vector. If the input of hash function is a binary number then HLI hash function only involves addition operations of modulo . So the time that used almost same with SWIFFT. The excellence of HLI hash function is the key size smaller than SWIFFT. This effect on
Keyword: hash function, modular polynomial ring, lattice