Judul: Pengaruh beberapa cara pengendalian gulma terhadap penutupan dan biomassa gulma di pastura alam
Abstrak: Penelitian ini dilakukan di Pastura Alam yang terletak di Unit Pendidikan dan Penelitian Peternakan Terpadu Jonggol, Fakultas Peternakan, Institut Pertanian Bogor, selama tiga bulan, dari bulan Maret sampai Juni 1988. Tujuan penelitian adalah untuk mempelajari pengaruh beberapa cara pengendalian gulma terhadap terhadap penutupan dan biomassa gulma di pastura alam Jonggol. Perlakuan yang diberikan yaitu: Kontrol (T0), Gulma dipotong 10 cm (T₁), Glipho- sat dosis 3.0 1/ha (T2), 2,4-D dosis 2.0 1/ha (T3), Piclo ram dosis 1.0 1/ha (T4), Potong 10 cm disemprot 2,4-D do sis 2.0 1/ha (T5), Potong 10 cm disemprot Picloram dosis 1.0 1/ha (T7), Bongkar disemprot Ametryne dosis 2.0 1/ha (T6), Bongkar (T8). Rancangan percobaan yang digunakan adalah Rancangan A- cak Kelompok. Untuk mempelajari nilai rataan dari masing-masing perlakuan digunakan Uji Jarak Duncan (Steel dan Torrie, 1981). Hasil penelitian menunjukkan bahwa pengaruh pengendalian gulma terhadap penutupan gulma Eupatorium odoratum, Melastoma affine, Lantana camara, Stachytarpheta jamaicensis adalah nyata (P/ 0.05) dari dua minggu sampai dua belas minggu setelah perlakuan. Pada perlakuan penyemprotan herbisida Gliphosat 3.0 1/ha (T), pembongkaran gulma yang diikuti penyemprotan herbisida Ametryne dosis 2.0 1/ha (T2), pembongkaran gulma (T7) cukup efektif untuk mengendalikan penutupan gulma Eupatorium odoratum, Melastoma affine, Lantana camara sampai dua belas minggu setelah perlakuan. Sedangkan perlakuan penyem- protan herbisida 2,4-D dosis 2.0 1/ha (T3), pembongkaran gulma yang diikuti penyemprotan herbisida Ametryne dosis 2.0 1/ha (T7), pembongkaran gulma (T8) ulma cukup efektif untuk mengendali- kan penutupan gulma Stachytarpheta jamaicensis sampai dua belas minggu setelah perlakuan. Sedangkan pengaruh pengendalian gulma terhadap biomassa gulma Eupatorium odoratum, Melastoma affine, Lantana camara, Stachytarpheta jamaicensis adalah nyata (P/ 0.05) dari satu sampai tiga bulan setelah perlakuan. Perlakuan penyemprotan herbisida Gliphosat dosis 3.0 1/ha T2), cukup efektif untuk mengendalikan biomassa gulma Eupa…dst
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Judul: Pengaruh berbagai cara pengendalian terhadap populasi dan biomassa beberapa jenis gulma di Padang Rumput Alam
Abstrak: Penelitian ini dilakukan di Unit Pendidikan dan Pene- litian Peternakan Jonggol (UP3J), Fakultas Peternakan, Institut Pertanian Bogor. Penelitian dilakukan selama em- pat bulan, sejak tanggal 27 Maret 1987 sampai tanggal 27 Juli 1987. Tujuan penelitian ini adalah untuk mempelajari efektifitas beberapa cara pengendalian gulma diukur dari biomassa dan perubahan jumlah individu gulma di padang rumput. Penelitian menggunakan Rancangan Acak Kelompok (RAK). Ada enam perlakuan yang diteliti pengaruhnya, yaitu pengolahan tanah, pemakaian herbisida 'preemergence' Diuron, herbisida 'pre-emergence Alachlor, herbisida 'postemergence 2,4-D, herbisida 'post-emergence Picloram, dan Kontrol. Untuk mengetahui pengaruh berbagai cara pengendalian terhadap masing-masing parameter, digunakan analisis sidik ragam yang dilanjutkan dengan uji jarak berganda Duncan. Hasil penelitian menunjukkan bahwa perlakuan tidak memberikan pengaruh yang berbeda nyata terhadap peningkatan jumlah individu gulma Chromolaena odorata, Lantana camara, Stachytarphe achytarpheta jamaicensis, serta gulma lain-lain (P0.05). Demikian pula terhadap biomassa masing-masing jenis gulma, kecuali Chromolaena odorata dan Melastoma m labathricum. Pengaruh perlakuan terhadap biomassa kedua jenis guima tersebut adalah berbeda nyata (P0.05). Perlakuan herbisida 'post-emergence 2,4-D dan Piclo- ram tidak berhasil menekan jumlah individu gulma Melastoma malabathricum. Namun perlakuan 'pre-emergence Diuron dan Alachlor, serta pembongkarn tanah, menenyatakan penyebaran M. malabathricum. Herbisida 'pre-emergence Diuron berhasil mene kan peningkatan jumlah individu gulma sampai tingkat yang pa- ling rendah dibandingkan yang lain….
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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