Judul: KUSWANDORA. CO2 Gas Emission and Carbon Balance on Corn, Peanut, and Cassava Fields in Ranca Bungur District, Bogor.
Abstrak: Perubahan iklim adalah salah satu isu global yang menjadi topik hangat diskusi seluruh dunia. Tiga gas rumah kaca (GRK) yang paling berkontribusi terhadap peningkatan emisi GRK yaitu CO2, CH4, dan N2O. Selain pada daerah industri, emisi gas CO2 dari lahan pertanian disinyalir tinggi. Namun, penelitian mengenai emisi CO2 dari lahan pertanian tropis sangat terbatas terutama pada tanah mineral. Beberapa penelitian dilakukan pada lahan gambut. Oleh karena itu, sangat penting untuk mengumpulkan informasi emisi CO2 pada tanah mineral tropis. Penelitian ini bertujuan untuk mengukur jumlah emisi CO2 pada penggunaan lahan yang berbeda, mengetahui faktor-faktor yang mempengaruhi emisi CO2, dan menghitung nilai neraca karbon pada masing-masing lahan di lokasi penelitian. Penelitian ini dilakukan pada lahan jagung, kacang tanah, dan singkong di Bogor, Jawa Barat, dari November 2010 sampai Juni 2011. Fluks CO2 diukur dengan metode ruang tertutup, dua ulangan pada baris, satu ulangan antar baris pada lahan jagung dan singkong, serta tiga ulangan pada kacang tanah (tidak ada baris). Variabel lingkungan seperti suhu udara, suhu tanah diukur pada kedalaman 5 cm, kelembaban udara, dan kadar air tanah juga diukur. Pengukuran fluks CO2 dan variabel lingkungan ini dilakukan setiap minggu dari penanaman sampai panen. Emisi CO2 dihitung dengan mengalikan fluks CO2 rata-rata dan durasi antara waktu sampling yang berdekatan. Dalam rangka untuk membandingkan setiap lahan, diasumsikan bahwa lahan ini dilanjutkan untuk ditanam tanaman yang sama selama satu tahun untuk perhitungan. Saat panen, seluruh bagian sampel tanaman diambil untuk diukur kadar karbonnya dengan menggunakan CHNS elemental analyzer. Semua tanaman ditanam pada bulan November 2010. Masa pertumbuhan pada lahan jagung, kacang tanah, dan singkong masing-masing adalah 77, 75, dan 218 hari. Emisi CO2 dari lahan jagung 14,95 ton C ha-1 thn-1, diikuti oleh 10,64 ton C ha-1 thn-1 pada lahan singkong, dan 10,07 ton C ha-1 thn-1 pada lahan kacang tanah. Pada lahan jagung dan singkong, fluks CO2 pada baris tanam lebih tinggi dari antar baris. Suhu tanah dan kadar air tanah berkorelasi positif dengan fluks CO2 pada baris, tapi tidak berkorelasi dengan fluks CO2 antar baris. Hasil ini menunjukkan bahwa aktivitas tanaman dapat mempengaruhi emisi CO2, kandungan air, dan suhu yang tinggi bisa meningkatkan CO2 yang dipancarkan dari tanah. Nilai Produksi Primer Bersih (PPB) untuk masing-masing lahan yaitu 21,98 ton C ha-1 thn-1 pada lahan jagung, 10,86 ton C ha-1 thn-1 pada lahan kacang tanah, dan 12,19 ton C ha-1 thn-1 pada lahan singkong. Terdapat hubungan positif antara emisi CO2 dan PPB.
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Judul: Fluks CO2 dari Andosol pada Penggunaan Lahan Kebun Sayur dan Hutan di Kecamatan Cisarua Kabupaten Bogor
Abstrak: Recently, agricultural activities are considered as one source of greenhouse gas emissions (GHG). Researchs on GHG emission from agricultural land are mostly done on peat soils, while researchs on mineral soil are still limited. This research was aimed to find out and to compare CO2 flux from vegetable garden, forest, and bare land on Andosol, and to compare CO2 flux from peat soils with these of mineral soils. This research was carried out at tea plantation area of PT Sumber Sari Bumi Pakuan, Tugu Utara Village, Cisarua District, Bogor Regency (Puncak area). Gas samples were taken using a chamber method and CO2 measurement was done using a CO2 Analyzer. The results of CO2 flux measurement of each of the land uses on Andosol indicate that CO2 flux from vegetable garden and forest were almost similar, about 4.26 g C-CO2/m2/d and 4.28 g C-CO2/m2/d, while that of bare land showed smaller results, about 2.0 g CCO2/ m2/d. The results of analysis of soil respiration showed the same thing that is CO2 produced from soil of vegetable garden and forest is higher than that of bare land. These results are resembled by the results of the analysis of microbial populations in the soils of vegetable garden and forest that were higher than that of the bare land. That facts indicate that the amount of CO2 flux are more originated from respiration activity that depends on the plants condition and the microbes activity. CO2 flux from three landuses of Andosol ranging from 1.00 to 6.00 g C-CO2/m2/d (3.65-21.90 tons C-CO2/ha/y). The amount of CO2 flux on this range is comparable with that of the CO2 flux from peat soil. CO2 flux from Andosol (high organic matter soil) in this research was lower than that from Latosol (low organic matter soil), indicating that the soil organic matter not directly influence the CO2 flux from the soil. Differences of soil and environmental conditions that affects of plant respiration and soil microbial at the study site are supposed to be a major factor in influencing the difference of CO2 flux.
Keyword: agricultural land, CO2 flux, Andosol

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