Judul: Potential Biomass, Carbon and CO2 Emissions on Necromass in Gunung Walat Educational Forest, Sukabumi Regency
Abstrak: Nekromassa merupakan bagian dari pohon yang telah mati baik yang masih berdiri tegak ataupun telah tumbang dan terletak di permukaan tanah. Potensi tegakan yang berada di Hutan Pendidikan Gunung Walat sangat beragam yang didominasi oleh tumbuhan berkayu dengan umur tegakan yang relatif tua. Pohon dengan diameter >30 cm dapat memberikan sumbangan yang cukup tinggi terhadap total biomassa pohon. Penelitian ini bertujuan mengetahui potensi biomassa, simpanan karbon dan emisi CO2 pada nekromassa. Teknik pengambilan data menggunakan metode simple random sampling. Plot contoh yang digunakan berbentuk persegi panjang dengan ukuran plot (20 m x 30 m) sebanyak 83 plot yang terbagi menjadi dua sub plot yaitu sub plot A (20 m x 30 m) untuk pengukuran kayu mati sedangkan sub plot B (20 m x 20 m) untuk pengukuran pohon mati. Pengambilan data di laboratorium dengan mengoven kayu mati pada suhu 105°C selama 24 jam. Hasil penelitian menunjukkan bahwa rata-rata potensi biomassa, karbon, dan emisi CO2 pada nekromassa berturut-turut yaitu sebesar 3,362 ton/ha, 1,543 ton/ha, dan 5,769 ton CO2/ha., Necromass is part of dead tree that is either still standing upright or has fallen and located on the ground. The potential of stands in Gunung Walat Educational Forest is very diverse, which is dominated by woody plants with relatively old stands. Trees with a diameter >30 cm can provide a high enough contribution to total tree biomass. This study aims to determine the potential of biomass, carbon storage and CO2 emissions in necromass. Data collection technique used simple random sampling method. The sample plot used is rectangular with plot size (20 m x 30 m) as many as 83 plots, which is divided into two sub plots, namely sub plot A (20 m x 30 m) for measuring dead wood while sub plot B (20 m x 20 m) for measuring dead tree. Data were collected in the laboratory by roasting dead wood at a temperature of 105°C for 24 hours. The results showed that the average potential for biomass, carbon, and CO2 emissions in necromass was 3,362 tons/ha, 1,543 tons/ha, and 5,769 tons CO2/ha.
Keyword: biomass, carbon, CO2 emissions, Gunung Walat, necromass

Judul: Dead Organic Matter’s Carbon Potential Estimation Based on Decomposition Level in Various
Abstrak: Hutan alam merupakan agen penting dalam mengurangi perubahan iklim global melalui penyerapan dan penyimpanan karbon dalam bentuk biomassa. Perubahan iklim global akibat naiknya konsentrasi gas rumah kaca (CO2, CH4, N2O, CFC) ke lapisan atmosfir sudah menimbulkan dampak lingkungan. Kadar CO2 dari tahun ke tahun terus mengalami peningkatan yang diakibatkan oleh aktivitas manusia. Salah satu tipe hutan yang memiliki potensi dalam penyerapan dan penyimpanan karbon ialah hutan rawa gambut. Karbon yang terdapat di hutan gambut tersimpan di atas dan bawah permukaan tanah.Sumber karbon hutan salah satunya terdapat pada bahan organik mati (nekromasa/kayu mati dan serasah) yang berpotensi untuk melepaskan CO2 ke atmosfir melalui proses dekomposisi. Penelitian ini bertujuan untuk menduga besarnya biomassa dan potensi karbon bahan organik mati di berbagai kondisi hutan gambut (primary forest,logged over area/LOA, secondary forest, dan degraded forest) berdasarkan tingkat dekomposisi tidak lapuk, setengah lapuk, dan lapuk untuk nekromasa serta dekomposisi kasar dan halus untuk serasah. Penelitian ini dilaksanakan di areal IUPHHK-HA PT. Diamond Raya Timber pada bulan Juni – Juli 2011, dilanjutkan dengan pengujian contoh nekromasa dan serasah di Laboratorium Departemen Hasil Hutan pada bulan Agustus-September 2011. Metode penelitian terdiri atas metode penelitian di lapangan dan metode penelitian di laboratorium. Metode penelitian di lapangan yaitu pengukuran bahan organik mati (petak ukur nekromasa 100 m x 100 m, dan serasah 1 m x 1 m), analisis vegetasi nekromasa, dan pengambilan contoh bahan organik mati. Sedangkan metode penelitian di laboratorium yaitu penentuan kadar air, berat jenis nekromasa, berat kering/biomassa, kadar zat terbang, kadar abu, kadar karbon (C%), dan potensi karbon bahan organik mati. Hasil penelitian ini menunjukan bahwa biomassa dan karbon nekromasa berdasarkan dekomposisi dari yang tertinggi sampai terendah yaitu tidak lapuk, setengah lapuk, dan lapuk. Pada serasah yaitu serasah kasar lebih besar dibandingkan serasah halus. Potensi biomassa dan karbon pada nekromasa di setiap kondisi hutan dari yang tertinggi sampai terendah yaitu LOA, degraded forest, secondary forest, dan primary forest. Pada serasah yaitu primary forest, LOA, degraded forest, dan secondary forest. Potensi biomassa pada nekromasa di setiap kondisi hutan rata-rata sebesar 51.12 ton/ha. Sedangkan pada serasah rataratanya sebesar 9.48 ton/ha. Potensi karbon pada nekromasa di setiap kondisi hutan rata-ratanya sebesar 24.22 tonC/ha. Sedangkan pada serasah rata-ratanya sebesar 3.18 tonC/ha.
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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