Judul: Kajian Teknologi Irigasi Bawah Tanah Dalam Pengelolaan Lahan Pasir (Studi Kasus di Desa Karangwuni, Kulon Progo, Yogyakarta)
Abstrak: Penelitian ini bertujuan untuk: (a) mengevaluasi teknologi irigasi bawah tanah peranan bio-teknologi dalam konservasi tanah dan air untuk lahan berpasir khususnya di lingkungan pesisir, (b) melihat ketersediaan airtanah dan keseimbangan airtanah daerah pesisir serta (c) melihat kedalaman intrusi air laut di wilayah pesisir. Metoda yang digunakan adalah dengan plot percobaan tanaman cabai merah keriting, dimana masing-masing mempunyai luas 6 x 3 sebanyak 16 buah dengan 2 kali ulangan. Setiap plot terdapat tingkat perbedaan perlakukan pemberian pupuk dan sistem penyiramannya (gembor dan irigasi bawah tanah). Melihat ketersediaan airtanah dan keberadaannya untuk konsumsi domestik dan pertanian serta kedalaman intrusi air laut dengan metode pumping test data dan geolistrik.
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Judul: Kinerja Penetes dan Rancangan Sistem Irigasi Tetes pada Lahan Pertanian di Desa Cikarawang Darmaga Bogor
Abstrak: Metoda irigasi tetes merupakan metoda irigasi yang telah dikembangkan dengan baik dengan keuntungan, antara lain : debit keluaran penetes yang kecil dengan tekanan operasi yang rendah dan disesuaikan dengan kebutuhan air tanaman, pembasahan dilakukan hanya pada daerah perakaran sehingga evaporasi dan perkolasi berkurang, meniadakan limpasan, menjaga kelembaban daerah perakaran selalu konstan. Penggunaan metoda irigasi tetes pada lahan pertanian dengan tanaman bernilai ekonomis tinggi serta kerentanan terhadap kekurangan air yang tinggi dapat meningkatkan hasil panen yang diperoleh karena kelembaban di daerah perakaran yang relatif konstan dapat terpenuhi. Masalah khusus ini bertujuan untuk mengamati kinerja penetes, mencari koefisien kekasaran pipa elastis berdin- ding ganda, mengamati diameter pembasahan dan kedalaman penetrasi air irigasi serta mengamati variasi tekanan dan debit keluaran penetes sepanjang saluran rancangan sistem. Lahan bernilai Bulk Density sebesar 0.9745 gr/cm³ dan bertekstur liat halus. Kadar air pada kapasitas lapang 49.4% dan 31.1% pada titik layu permanen. Kecepatan infil- trasi potensial tanah sebesar 11 20.417 -0.4828 dan 12 11.482 -0.3617 (cm/jam) pada kadar air 50.3% sedang ..dst
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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