Judul: Perencanaan interpretasi kawasan Danau Toba dan Pulau Samosir
Abstrak: Penelitian ini bertujuan untuk menyusun perencanaan interpretasi kawasan Danau Toba dan Pulau Samosir dengan langkah menentukan tujuan interpretasi, mengidentifikasi dan menganalisis objek interpretasi, menentukan tema, serta menyusun skenario cerita interpretasi. Metode yang digunakan dalam pengambilan data adalah studi literatur, wawancara dan observasi lapang. Objek interpretasi yang diidentifikasi adalah objek geologis berupa sejarah proses terbentuknya Danau Toba dan Pulau Samosir, objek biologis berupa flora dan fauna serta budaya masyarakat yakni legenda dan mitos. Kondisi keanekaragaman flora dan fauna di kawasan Danau Toba dan Pulau Samosir beragam karena terdapat beberapa jenis burung dan tumbuhan langka. Sementara itu, masyarakat di kawasan Danau Toba dan Pulau Samosir pada umumnya masih mempercayai adanya legenda dan mitos yang berhubungan dengan Danau Toba. Skenario cerita interpretasi yang disusun adalah proses terjadinya Danau Toba dan Pulau Samosir yang terbentuk melalui proses tektonik dan vulkanik dengan letusan gunung api raksasa (supervulcano) Gunung Toba
Keyword: biodiversity, geodiversity, interpretation planning.

Judul: Rencana penataan kawasan wisata berkelanjutan di Danau Toba Sumatera Utara (Kasus: Sub DAS Naborsahon)
Abstrak: Lake Toba is the biggest lake in South East Asia, in the middle of which Samosir Island occurs, is located at 906-1800 m above sea level with mountainous landscape providing natural freshness and lake visual potential. The natural beauty of Lake Toba makes this region one of potential tourism spots, locallyand internationally. Nowadays, both physical and visual scenic qualities of this region have been declining which are affected by the increasing number of visitation and mushrooming of tourism infrastructures.
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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