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: Estimation of Biomass, Carbon and CO2Emissions in Litter and Humus in Gunung Walat Educational Forest, Sukabumi Regency
Abstrak: Hutan Pendidikan Gunung Walat (HPGW) sebagai hutan tanaman memiliki kontribusi serasah dan humus yang cukup tinggi terhadap potensi biomassa, karbon dan emisi CO2. Hal itu dikarenakan serasah dan humus di HPGW sangat melimpah. Penelitian ini bertujuan untuk menduga potensi biomassa, karbon dan menduga emisi CO2 di HPGW. Pengambilan data di lapangan dilakukan secara destruktif dengan metode simple random sampling yaitu peletakan plot contoh secara acak agar menggambarkan dan mewakili tiap tegakan yang ada di HPGW. Plot contoh berbentuk persegi dengan ukuran (2 x 2) m dengan total plot sebanyak 83 plot dengan total sampel yang diambil sebanyak 166 sampel. Pengambilan data di laboratorium dengan mengoven serasah dan humus pada suhu 105 °C selama 24 jam. Hasil dugaan biomassa serasah dan humus secara berturut-turut sebesar 3,91 ton/ha dan 0,923 ton/ha. Pendugaan karbon serasah dan humus secara berturut-turut sebesar 1,839 ton/ha dan 0,434 ton/ha. Emisi CO2 dari proses dekomposisi serasah dan humus secara berturut-turut diperkirakan sebesar 6,74 ton CO2/ha dan 1,59 ton CO2/ha., Gunung Walat Educational Forest (HPGW) as a plantation forest has a high litter and humus contribution to the potential for biomass, carbon and CO2 emissions. because the litter and humus in HPGW is very abundant. The purpose of this research is to estimate the potential of biomass, carbon and to estimate CO2 emissions in HPGW. Data collection in the field was carried out destructively with the simple random sampling method, namely the placement of sample plots at random in order to describe and represent each stand in the HPGW. The sample plots are square with the size (2 x 2) m with a total plot of 83 plots with a total of 166 samples taken. Data were collected in the laboratory by roasting the litter and humus at a temperature of 105 °C for 24 hours. The estimated results of litter and humus biomass were 3.91 tons/ha and 0.923 tons/ha, respectively. Estimation of litter and humus carbon was 1.839 tons/ha and 0.434 tons/ha, respectively. CO2 emissions from the decomposition of litter and humus were estimated at 6.74 tons CO2/ha and 1.59 tons CO2/ha, respectively.
Keyword: biomass, carbon, CO2 emissions, humus, litter

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