Judul: Keanekaragaman Tumbuhan Paku (Pteridophyta) di Taman Kota Bumi Serpong Damai, Tangerang Selatan
Abstrak: Tumbuhan paku yang dijumpai di ruang terbuka hijau cukup beragam meliputi kelompok epifit dan terestrial. Taman kota berfungsi sebagai area rekreasi publik. Tumbuhan paku di taman kota berperan dalam menyeimbangkan ekosistem. Keanekaragaman tumbuhan paku di hutan alami sudah banyak dilaporkan sebelumnya, namun untuk taman kota belum banyak dikaji. Penelitian ini bertujuan mengidentifikasi tumbuhan paku, serta menganalisis komposisi dan keterkaitan antara kondisi iklim mikro terhadap keanekaragaman tumbuhan paku di Taman Kota Bumi Serpong Damai, Tangerang Selatan. Data keanekaragaman tumbuhan paku diperoleh dengan metode kuadrat bertingkat dan pembuatan plot (2 m x 2 m untuk paku terestrial dan 60 cm x 50 cm untuk paku epifit). Faktor yang berpengaruh terhadap keanekaragaman tumbuhan paku dianalisis dengan Principal Component Analysis (PCA). Tumbuhan paku di Taman Kota Bumi Serpong Damai, Tangerang Selatan berjumlah 14 spesies termasuk dalam 9 famili yang terdiri atas 10 paku terestrial dan 4 paku epifit. Faktor-faktor yang mempengaruhi keanekaragaman tumbuhan paku yaitu kelembapan, suhu, intensitas cahaya dan kecepatan angin. Paku terestrial yang memiliki indeks nilai penting tertinggi yaitu Cyclosorus heterocarpus (74,95%) dan paku epifit yaitu Drynaria quercifolia (83,80%)., The ferns found in green open spaces are quite diverse, including epiphytic and terrestrial groups. City parks serve as public recreation areas. Ferns in city parks play a role in balancing the ecosystem. The diversity of ferns in natural forest has been reported before, but for city parks it has not been studied much. This study aimed to identify fern, as well as analyze the composition and association between microclimate conditions to the diversity of fern in Taman Kota Bumi Serpong Damai, South Tangerang. Data on the diversity of ferns were obtained by stratified squares method and plotting (2 x 2 m for terrestrial fern and 60 x 50 cm for epiphytic fern). Factors that influence the diversity of ferns were analyzed using Principal Component Analysis (PCA). There are 14 species of ferns in Bumi Serpong Damai City Park, including 9 families, consisting of 10 terrestrial ferns and 4 epiphytic ferns. The factors that influence the diversity of ferns are humidity, temperature, light intensity and wind speed. The terrestrial fern with the highest index of importance was Cyclosorus heterocarpus (74.95%) and epiphytic fern was Drynaria quercifolia (83.80%).
Keyword: epiphytic ferns, microclimate, PCA, terrestrial ferns

Judul: Keanekaragaman Tumbuhan Paku Terestrial di Hutan Kota DKI Jakarta
Abstrak: Urban forest is an ecosystem consisted of plant vegetation community that resembles natural forest. Trees within the urban forest form canopy that construct well-suited environment for the understory life. One of the understory is fern. Fern is a vascular and intermediate plant that produces spores as its main characteristic. This research was intended to compare the diversity of fern under three urban forests in DKI Jakarta region which were the urban forest University of Indonesia (UI), Arboretum Cibubur, and urban forest PT Jakarta Industrial Estate Pulogadung (PT JIEP) Pulogadung. The research was started in November 2011 until March 2012. Vegetation analysis was made by doing purposive sampling with square method. Fern and non-fern specimens were collected for herbarium purpose then were identified based on identification book. Light intensity, temperature, humidity, soil pH were measured and recorded as supported data. The other environment factors that measured were physical and chemical structures of soil and also the quality of the air. The coverage data and the frequency of each species were used to count the importance value index (INP). Sharon Diversity Index (H'), Evenness Index (E), and Sorenson Similarity Index (IS) were also counted in. There were epiphytes fern (4 species) and terrestrial fern (18 species) in the research urban forest. The ferns have herb habit, but they varied in the growth types which are erect; creeping and climbing. Fern leaves have variation in size, shape of fertile and sterile leaves, shape of the first leaf and so on. Based on the leaf size, two kinds of leaf, microphyl and megaphyl, were found. Based on the different shape of fertile and sterile leaves, monomorphyc and dimorphic leaves were found. The shape of monomorphyc leaf varied which were simple, pinnatus and bi-pinnatus. Fern reproductive structure in urban forest varies in the sori shape, location and composition, such as 1) sporangium is located in the leaf tips, form organ so called as strobilus; 2) longitudinal grooved sori on the edge as though covering the edge; 3) sori is located along vascular leaf between costa and the edge of the leaf; 4) sori is rounded or oval spreaded on the vascular leaf with or without indusium; 5) sori is rounded or oval, located on the tips on the free vascular near the leaf edge; 6) sori on the fertile leaflet produces sporangia that spread from the edge of the leaf to the venation tips. Sporangia on two rows is covered by indusia. The sum of terrestrial ferns found in three research urban forests were 18 species belong to 8 familia and 11 genera. In UI urban forest, it was found 10 genera with 14 species; in Arboretum Cibubur, it was found 8 genera with 11 species; but there was no fern in PT JIEP urban forest. The number of all individual ferns found in three urban forest were 1030, consisted of 334 individual in Arboretum Cibubur urban forest and 696 in UI urban forest. The species diversity index (H' = 1.97) and evenness index (E = 0.82) in Arboretum Cibubur urban forest was higher than that of
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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