Judul: Kemampuan eceng gondok (eichornia crassipes) untuk menurunkan kadar timbal dalam air tawar
Abstrak: Kemampuan eceng gondok dalam menurunkan kadar Pb di dalam air tawar telah dilaksanakan dalam penelitian ini. Satu, tiga dan lima rumpun eceng gondok ditempatkan dalam ember plastik yang berisi air sumur dan larutan Pb(NO₂), 5 ppm. Konsentrasi Pb diukur ketika hari ke-0, 7, 14, 21, dan 28 dengan spektrofotometer serapan atom pada panjang gelombang 217 nm. Hasil penelitian membuktikan bahwa eceng gondok dapat menurunkan kadar logam Pb dengan cepat. Setelah hari ke-7 kadar logam Pb menurun hingga 95,0% perlakuan 1 eceng gondok, 97,3% untuk perlakuan 3 eceng gondok dan 98,5% untuk perlakuan 5 eceng gondok dari konsentrasi hari ke-0. Analisis pada hari selanjutnya menunjukan perubahan kadar logam Pb tidak terlalu jauh dengan kadar logam Pb pada hari ketujuh.
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Judul: Kapasitas eceng gondok (Eichornia crassipes) dalam menurunkan konsentrasi logam Fe di perairan tawar
Abstrak: Kemampuan eceng gondok dalam menurunkan konsentrasi logam besi di perairan tawar telah dilaksanakan. Satu, dua, dan tiga rumpun eceng gondok ditempatkan dalam ember plastik yang berisi air sumur, FeSO4 5 ppm dan ditambahkan HNO3 untuk menjaga keasaman. Konsentrasi Fe diukur pada hari ke-0, 7, 14, 21, dan 28 dengan menggunakan spektrofotometer serapan atom pada panjang gelombang 248,3 nm. Hasil penelitian menunjukkan bahwa semakin hari logam besi yang terserap semakin banyak. Dan pada hari ke-28 konsentrasi Fe hampir mendekati 0 untuk perlakuan 2 (menggunakan 2 numpun eceng gondok) dan perlakuan 3 (menggunakan 3 rumpun eceng gondok). Berdasarkan analisis statistik diketahui balıwa pada hari ke-7, 14 dan 21, eceng gondok memberikan respon yang nyata dalam menurunkan logam Fe untuk ke-3 perlakuan. Namun pada hari ke-28 eceng gondok yang berjumlah 2 dan 3 rumpun memberikan respon yang tidak berbeda nyata dalam menurunkan logam besi. Penurunan yang drastis terjadi pada awal perlakuan yaitu mencapai 3.177 ppm (65.45%) untuk 1 rumpun eceng gondok, 3.511 ppm (71.93%) untuk 2 rumpun eceng gondok dan 3.686 ppm (74.47%) untuk 3 rumpun eceng gondok.
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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