Judul: Peranan vegetasi sebagai indikator pencemaran udara di daerah Bogor dan sekitarnya
Abstrak: Tumbuhan selain mempunyai potensi mengurangi pencemaran udara, dapat juga digunakan sebagai indikator pencemaran, berdasarkan kepada gejala makroskopis, gejala mikroskopis (sitologi) maupun gejala fisiologis (seperti penurunan kandungan klorofil-a) dan biokimia. Penelitian ini bertujuan untuk mengkaji peranan vegetasi sebagai indikator pencemaran udara, khususnya terhadap pencemaran SO₂ dan debu terutama akibat kegiatan transportasi di Kebun Raya Bogor/KRB (daerah hutan kota), Terminal Bis Baranang Siang/TBS (daerah padat kendaraan) dan Kompleks Perumahan Villa Duta Baranang Siang/VD, berdasarkan kandungan klorofil-a dan abnormalitas sel pada daun. Bahan yang digunakan untuk analisa kandungan klorofil-a yaitu daun dari 9 jenis pohon (Mimusops elengi, Pterocarpus indicus, Artocarpus heterophyllus, Mangifera indica, Bauhinia purpurea, Lagerstroemia speciosa, Acacia auriculiformis, Psidium guajava dan Ficus benjamina), yang terdapat di sekitar lokasi pengambilan sampel udara, baik daun muda, daun dewasa maupun daun tua. Preparat daun hanya dibuat untuk daun Pterocarpus indicus dan Artocarpus heterophyllus. Sebagai permbanding, diambil contoh daun dari Kompleks Perumahan Dosen di Kampus IPB Darmaga. Metode yang digunakan untuk mengetahui kandungan SO, yaitu Metode Pararosanilin (metode spektrofotometri), sedangkan debu dengan metode gravimetri. Kandungan klorofil- a diukur dengan metode spektrofotometri. Penghitungan abnormalitas sel, pengukuran panjang dan lebar sel daun dilakukan pada semua jaringan daun (epidermis atas/bawah, palisade dan bunga karang).
Keyword: vegetasi

Judul: Dampak Pencemaran Udara Terhadap Tumbuhan di Kebun Raya Bogor
Abstrak: The Bogor Botanical Garden is the one of the biggest and most complete botanical garden in the world. But recently, pollution sources around of the garden such as motor vehicles could be harms to the garden. Air pollution gasses such as SO,,NO, and Pb particle are released by the motor vehicles and known as a phytotoxic agent. The objective of this research is to study the impact of the air pollution on the vegetation by measuring; concentration of SO,, NO, and Pb particles in the air, chlorotic and necrotic damage level on the leaves, damage percentage and the measurement of the cells and chlorophyll content in the leaves. This research was conducted from August 1997 to Februw 1998. Research used seven plots and nineteenth plants species of dicotyl class. Air pollution gasses were observed by Spectrophotometer and Pb particles by Atomic Absorption Spectrophotometer. Chlorotic and necrotic damages were observed by magnifying glass, cells damages and measurement by microscope, and leaves chlorophyll content by Spectrophotometer. Varian, regression and descriptive analysis analyzed data. The result of this research shows that pollution by SO2, NO2 gasses and Pb particles in the air of the garden mostly higher in every side of the garden. NO2 and Pb particles polluted the garden over the threshold limit allowed. Statistic analysis result that from the three pollutants in the air observed NO2 was only significant between plots. The concentration was mostly influenced by -amount of motor vehicles and wind directions. The impact on the vegetation showed that there are no both chlorotic and necrotic on the 19 plant species observed, so it was classified as zero in Kovack's levels. Cells damage was variously founded from one species to another. The highest damage was founded on F. Racemosa, V.cofassus and T. Hornemanium, which are growth on the roadside plots and highly air pollutant concentration. Chlorophyll content are significant different between species in each plot and was influenced by air pollution. The impact on kenari (C. vulgare) plant clearly observed that the leave cells anatomy measured become narrower, chlorophyll content lower and Pb particles higher when the air pollutants concentration are high.
Keyword: 

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