Judul: Pengelolaan Tanaman Tebu (Saccharum officinarum L.) di Pabrik Gula Madukismo, PT Madubaru, Yogyakarta dengan Aspek Khusus Mempelajari Produktivitas Tiap Kategori Tanaman dan Tipe Kemasakan.
Abstrak: Pengelolaan tanaman tebu dilakukan untuk menghasilkan produksi tebu serta rendemen yang optimal. Teknik budidaya yang belum baik serta keprasan yang lebih dari tiga kali menyebabkan produktivitas tebu mengalami penurunan. Kegiatan magang dilaksanakan mulai 6 Februari 2017 hingga 5 Juni 2017 di wilayah kerja PG. Madukismo, PT. Madubaru, Yogyakarta. Kegiatan magang ini secara khusus bertujuan untuk menganalisis produktivitas tiap kategori tanaman dan tipe kemasakan. Hasil pengamatan menunjukkan produktivitas pada lahan kering wilayah Bantul dan Purworejo naik pada kategori tanaman RC I kemudian turun pada kategori tanaman berikutnya. Produktivitas varietas masak tengah lambat wilayah Bantul lebih tinggi daripada wilayah Purworejo. Pengukuran brix yang dilakukan pada bulan Mei menunjukkan bahwa varietas masak tengah lambat memiliki rendemen yang rendah pada saat masa awal giling pabrik gula.
Keyword: awal giling, kemasakan, keprasan, rendemen

Judul: Pengelolaan Tanaman Tebu (Saccharum Officinarum L.) Di Pabrik Gula Madukismo Dengan Aspek Khusus Penataan Varietas
Abstrak: Salah satu langkah dalam meningkatkan produktivitas dan rendemen tebu adalah dengan mengelola tanaman tebu secara maksimal. Penataan varietas perlu dilakukan untuk menghasilkan tebu sesuai potensi produksinya dan mendapatkan rendemen maksimal selama musim giling. Kegiatan magang ini bertujuan untuk mengidentifikasi dan menganalisis penataan varietas tebu terutama di pabrik gula Madukismo. Kegiatan magang dilaksanakan di Pabrik Gula Madukismo pada tanggal 9 Februari 2015 hingga 8 Juni 2015. Pengamatan dilakukan dengan menganalisis tipologi lahan wilayah kerja PG Madukismo, data komposisi varietas tebu di kebun tebu giling dan data komposisi varietas di kebun bibit datar, serta melakukan wawancara kepada petani tebu mandiri wilayah binaan PG Madukismo. Tipologi lahan wilayah kerja Madukismo secara umum sesuai dengan syarat tumbuh tanaman tebu. Komposisi varietas di kebun tebu giling PG Madukismo belum mencapai komposisi ideal namun PG Madukismo telah mulai memperbaiki penataan varietas di kebun pembibitannya. Masih banyaknya petani mandiri wilayah binaan PG Madukismo yang fanatik terhadap varietas PS 862 dan BL menyebabkan penataan varietas sulit dilakukan.
Keyword: komposisi varietas, petani tebu, tipologi lahan

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