Judul: Potensi Verbena brasiliensis Vell. sebagai Tumbuhan Invasif di Resort Ranu Pani Taman Nasional Bromo Tengger Semeru Jawa Timur
Abstrak: Salah satu bentuk ancaman dan gangguan lingkungan yang sedang menjadi isu global adalah invasi jenis asing yang mampu menurunkan keanekaragaman hayati. Selain merubah komunitas, keberadaan jenis invasif dapat menggangu kestabilan struktur serta fungsi ekosistem yang terinvasi. Verbena brasiliensis Vell. adalah jenis native Amerika Selatan yang diduga berpotensi invasif di wilayah Resort Ranu Pani Taman Nasional Bromo Tengger Semeru, Jawa Timur. Jenis tersebut telah berhasil tumbuh subur dan menyebar luas di kawasan padang rumput Oro-Oro Ombo. Luas tutupan V. brasiliensis di wilayah tersebut diperkirakan mencapai ±20 ha, sedangkan tutupan jenis rumput semakin menyempit. Adanya simpanan propagul dan aktifitas manusia menjadikan invasi V. brasiliensis berpotensi semakin luas ke wilayah Resort Ranu Pani lain. Pengelolaan terhadap V. brasiliensis penting segera dilakukan untuk mencegah perluasan persebaran dan dampak lebih buruk dari invasi. Langkah awal perumusan pengelolaan V. brasiliensis adalah dengan mengumpulkan informasi mengenai dampak invasi, karakter biologi jenis, dan potensi persebaran di wilayah lain. Penelitian ini dilaksanakan dengan tujuan: 1) Menguraikan dampak invasi V. brasiliensis terhadap keanekaragaman dan komposisi vegetasi Oro-Oro Ombo; 2) Menguraikan karakter perkecambahan, pertumbuhan, potensi penghambatan melalui alelopati, dan kemampuan bertunas pasca kerusakan tajuk yang menyebabkan keinvasifan V. brasiliensis; 3) Menganalisis potensi persebaran V. brasiliensis di wilayah Resort Ranu Pani. Pengambilan data vegetasi dilakukan di Oro-Oro Ombo mewakili wilayah terinvasi V. brasiliensis, dan Pangonan Cilik mewakili wilayah yang belum terinvasi V. brasiliensis. Pengambilan data pertumbuhan dan kemampuan bertunas pasca kerusakan tajuk dilakukan di Oro-Oro Ombo. Percobaan perkecambahan dan potensi penghambatan alelopati dilakukan di Laboratorium Ekologi dan Sumber Daya Tumbuhan Departemen Biologi FMIPA Institut Pertanian Bogor. ...
Keyword: dampak invasi, karakter penyebab invasif, Oro-Oro Ombo, potensi persebaran, Verbena brasiliensis

Judul: Potensi Invasif Trembesi (Samanea saman Jacq.) di Zona Rehabilitasi Taman Nasional Meru Betiri, Jawa Timur
Abstrak: Tumbuhan asing invasif merupakan tumbuhan yang hidup di luar habitat alaminya, tumbuh dengan pesat karena tidak mempunyai musuh alami sehingga menjadi gulma, hama, dan penyakit pada spesies-spesies asli. Trembesi merupakan salah satu spesies eksotik yang berpotensi invasif. Penelitian ini bertujuan mengidentifikasi komposisi dan struktur vegetasi dan mengidentifikasi potensi invasif trembesi (Samanea saman Jacq.) di zona rehabilitasi Taman Nasional Meru Betiri, Jawa Timur. Metode yang digunakan yaitu analisis vegetasi kombinasi jalur dan garis berpetak, diagram profil, serta sebaran titik sebaran trembesi dengan GPS. Berdasarkan penelitian didapat 2 spesies pada tingkat semai yaitu Samanea saman dan Aleurites moluccana, 2 spesies pada tingkat tiang yaitu Parkia timoreniana dan Alstonia scholaris, serta 6 spesies pada tingkat pohon yaitu Parkia timoreniana, Samanea saman, Aleurites moluccana, Pangium edule, Alstonia scholaris dan Parkia speciosa. Pola sebaran trembesi secara umum adalah seragam. Potensi invasif trembesi di Zona Rehabilitasi, Resort Andongrejo Taman Nasional Meru Betiri belum nampak terjadi dikarenakan tingkat regenerasinya relatif rendah.
Keyword: invasif, pola sebaran, taman nasional Meru Betiri, trembesi, zona rehabilitasi

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