Judul: Estimation of Potential Carbon Stock Area of Taman Kehati, PT Tirta Investama Plant Ciherang, Bogor
Abstrak: Karbon merupakan salah satu komponen biomassa yang ada pada suatu tegakan hutan. PT Tirta Investama Plant Ciherang selain memiliki luasan tegakan hutan (kawasan hijau) yang lebih luas dibandingkan luasan kawasan terbangunnya, ia juga berkomitmen untuk terus menjaga lingkungan terutama dapat ikut serta menyerap karbon yang menjadi salah satu unsur penting dalam perubahan iklim. Penelitian ini bertujuan untuk mengetahui nilai besaran potensi dugaan stok karbon, serapan karbon dioksida (CO2), dan peta sebaran potensi dugaan stok karbon yang ada di tegakan PT Tirta Investama Plant Ciherang. Metode yang digunakan yaitu dengan mengidentifikasi dan mengukur secara langsung diameter dan tinggi pohon, serta menggunakan literatur untuk data pendukung seperti pemilihan persamaan allometrik. Hasil dari penelitian ini didapatkan bahwa total potensi dugaan stok karbon sebesar 6842,84 ton/ha, sedangkan serapan CO2 sebesar 25113,22 ton/ha. Peta potensi pendugaan stok karbon menggambarkan bahwa dari 95 petak terdapat 66 petak potensi dugaan stok karbon dengan kelas rendah (0,00–90,00 ton/ha). Besar kecilnya nilai dari potensi dugaan stok karbon sangat dipengaruhi dari besar kecilnya diameter tegakan, sehingga apabila rata-rata diameter tegakan semakin besar, maka potensi dugaan stok karbon akan semakin tinggi.
Keyword: allometric, biomass, carbon, carbon distribution map, CO2 absorption

Judul: Estimation of Biomass, Carbon Stock, and CO2 Uptake in Various Age Classes of Teak Stands in RPH Cipeundeuy, KPH North Bandung
Abstrak: Ekosistem hutan berperan penting dalam siklus karbon dunia, khususnya hutan tropis karena memiliki potensi terbesar dalam mitigasi CO2 dengan karbon yang tersimpan dalam biomassa hidup, tanah hutan, hingga kayu mati. Indonesia sangat berpotensi menjadi negara dengan penyerap emisi karbon karena mempunyai hutan tropis yang luas. Tujuan penelitian ini, yakni mengetahui dugaan biomassa dan stok karbon pada berbagai kelas umur tegakan Tectona grandis serta potensinya dalam menyerap karbondioksida (CO2) serta memproduksi oksigen (O2). Metode yang digunakan dalam pengambilan data, yakni menggunakan Stratified Sampling dengan plot persegi berukuran 25 m x 25 m sebanyak 55 plot. Kandungan biomassa diduga menggunakan persamaan alometrik. Hasil penelitian menunjukan simpanan biomassa 44.456,8 ton, stok karbon 22.228,4 ton, serapan CO2 163.156,6 ton, dan produksi O2 59.275,8 ton., Forest ecosystems play an important role in the world's carbon cycle, especially tropical forests because they have the greatest potential for CO2 mitigation with carbon stored in living biomass, forest soil, and dead wood. Indonesia has the potential to become a country that absorbs carbon emissions because it has extensive tropical forests. This study aims to determine the estimation of biomass and carbon stock in various age classes of stands of Tectona grandis and their potential to absorb carbon dioxide (CO2) and produce oxygen (O2). The data collection is using stratified sampling with 55 square plots (25 x 25 m). The biomass content was estimated using the allometric equation. The results showed that the biomass content of the stands was simpanan biomassa 44.456,8 ton , stok karbon 22.228,4 ton, produksi O2 59.275,8 ton, dan serapan CO2 163.156,6 ton, the carbon stock of the stands was 22.228,4 ton, the CO2 absorption potential of the stands was 163.156,6 ton, and the O2 production potential of the stands was 59.275,8 ton.
Keyword: biomass, carbon, oxygen, Tectona grandis, carbon dioxide

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm