Judul: Respon Pertumbuhan Kayu Afrika (Maesopsis eminii Engl.) terhadap Pemberian Pupuk Kompos dan Dolomit pada Media Tanah Tercemar Oli Bekas
Abstrak: Penggunaan minyak pelumas mesin seperti oli dapat menjadi limbah apabila tidak disimpan dan dikelola dengan benar, sehingga dapat berdampak pada pencemaran lingkungan hidup. Penanaman Maesopsis eminii Engl. serta pemberian pupuk kompos dan dolomit dapat memperbaiki ekosistem yang rusak akibat pencemaran oli bekas. Penelitian ini bertujuan untuk menganalisis pengaruh pemberian pupuk kompos dan dolomit terhadap respon pertumbuhan bibit kayu afrika pada media tanah tercemar oli bekas serta memperoleh informasi mengenai dosis pemberian pupuk kompos dan dolomit yang optimal untuk pertumbuhan bibit kayu afrika pada media tanah tercemar oli bekas. Hasil penelitian ini menunjukkan bahwa pemberian pupuk kompos, dolomit serta interaksi pupuk kompos dan dolomit tidak berpengaruh nyata terhadap parameter tinggi, nisbah pucuk akar, dan panjang akar. Pemberian pupuk kompos berpengaruh nyata pada parameter diameter dengan dosis terbaik 120 g pupuk kompos. Pemberian pupuk kompos dengan dosis 40 g berpengaruh nyata pada parameter berat basah total dan berat kering total. Pemberian pupuk kompos 80 g dan 40 g dolomit memberikan respon terbaik pada respirasi tanah (jumlah CO2).
Keyword: dolomit, Maesopsis eminii, oli bekas, pupuk kompos

Judul: Respon Pertumbuhan Kayu Afrika (Maesopsis eminii) terhadap Pemberian Kompos dan Arang pada Tanah Tercemar Oli Bekas
Abstrak: Degradasi kualitas tanah akibat tercemar limbah oli bekas dapat dihentikan dengan penanaman jenis komersil seperti kayu afrika (Maesopsis eminii Engl.) serta pemberian pupuk kompos dan arang tempurung kelapa. Tujuan penelitian ini adalah menganalisa respon pertumbuhan kayu afrika terhadap pemberian kompos dan arang tempurung kelapa pada media tercemar oli bekas, serta memperoleh informasi mengenai dosis pemberian pupuk kompos dan arang tempurung kelapa yang optimal dalam pertumbuhan bibit kayu afrika pada media tercemar oli bekas. Penelitian ini menggunakan 60 bibit kayu afrika dan oli bekas dengan konsentrasi 60 ml/kg media, dengan metode Rancangan Acak Lengkap (RAL). Hasil penelitian menunjukkan bahwa pemberian arang tempurung kelapa tunggal berpengaruh nyata pada parameter tinggi dengan dosis terbaik 0 gram (A0). Pemberian dosis pupuk kompos 40 gram dan arang tempurung kelapa 10 gram (K1A1) memberikan respon terbaik pada parameter berat basah total. Pemberian dosis pupuk kompos 80 gram dan arang tempurung kelapa 40 gram (K2A4) memberikan respon terbaik pada panjang akar bibit kayu afrika. Pemberian kompos dan arang menurunkan konsentrasi Pb sebesar 0.73 ppm.
Keyword: Arang, kompos, Maesopsis eminni, oli bekas

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