Judul: Pengamatan Penyakit Penting Karet (Havean brasilliensis Muell. Arg) Da Usaha Pengendaliannya Di Perkebunan Ngobo, PTP XVIII (Persero) Semarang-Jawa Timur
Abstrak: Praktek Lapang ini dilakukan di afdeling Klepu dan Jatirunggo Perkebunan Ngobo, dengan tujuan untuk mengetahui luas dan intensitas serangan penyebab penyakit penting karet di pertanaman tua yang telah menghasilkan lateks (TM) dan di pertanaman muda yang belum menghasilkan (TBM). Selain mengamati penyakitnya, dilakukan juga pengamatan usaha pengendalian penyakit di perkebunan tersebut. Penyakit penting tanaman karet yang terdapat di Perkebunan Ngobo adalah penyakit cendawan akar putih (pada akar), penyakit jamur upas (pada cabang), penyakit mouldy rot, penyakit kanker garis dan penyakit kulit dalam coklat (pada bidang sadap) serta beberapa penyakit daun seperti penyakit gugur daun Corynespora, penyakit bercak daun Cylindrocladium, dan penyakit gugur daun Colletotrichum. Penyakit-penyakit tersebut dapat mengurangi hasil serta ketahanan pohon karet. Terjadinya penyakit penting di Perkebunan Ngobo selalu ada setiap waktu walaupun dalam persentase serangan ringan, kecuali penyakit gugur daun. Corynespora yang merupakan penyakit baru dan menimbulkan masalah yang cukup berarti untuk tahun 1985. Hasil pengamatan menunjukkan bahwa di Perkebunan Karet Ngobo terdapat perbedaan luas dan intensitas serangan penyakit akibat perbedaan umur tanaman di masing-masing blok pertanaman yang ada. Penyakit cendawan akar putih dan penyakit jamur upas ditemukan di pertanaman tua yang telah menghasilkan dan di pertanaman muda yang belum meng- hasilkan, walaupun demikian banyak dan lebih parah keada- annya di pertanaman muda. Diduga salah satu penyebabnya yaitu ketahanan pohon muda lebih rendah dibandingkan de- ngan pohon tua. Sebaliknya penyakit yang hanya dijumpai di pertanaman tua yang telah lama menghasilkan lateks yaitu penyakit bidang sadap. Timbulnya penyakit bidang sadap diperkirakan akibat sistem penyadapan yang cukup berat sehingga melemahkan ketahanan pohon…dst
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Judul: Pengamatan Penyakit penting Tanaman Karet (Hevea Muell, Arg.) dI Wilayah Kerja Balai Penyuluhan Pertanian Cikalongkulon Kabupaten Cianjur- Jawa Barat
Abstrak: Survai ini dilakukan di perkebunan karet rakyat desa Mekargalih, desa Cijagang dan desa Majalaya, dengan tujuan untuk menghitung luas serangan patogen yang ada dan intensitas serangan patogen penting pada tanaman karet yang telah menghasilkan lateks (TM) dan pada tanaman karet muda yang belum menghasilkan (TBM). Selain mengamati panyakitnya, juga dilakukan pengamatan sepintas hama yang ada di perkebunan karet rakyat tersebut. Penyakit penting tanaman karet yang terdapat di perkebunan karet rakyat Wilayah Kerja Balai Penyuluhan Pertanian Cikalongkulon ialah gugur daun (Colletotrichum gloeosporioides), embun tepung (Oidium heveae), bercak daun (Cephaleuros sp.), mati pucuk (Botryodiplodia theobromae), mouldy rot (Ceratostomella fimbriata) dan benalu (Loranthus sp.) serta defisiensi kalium. Penyakit-penyakit tersebut dapat mengurangi hasil serta ketahanan pohon karet. Penyakit gugur daun karet yang disebabkan oleh cendawan Colletotrichum gloeosporioides merupakan penyakit yang dominan di perkebunan karet rakyat di daerah ini. Menurut keterangan petugas Dinas Perkebunan setempat, daerah ini merupakan daerah asal eksplosi serangan patogen tersebut.
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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