Judul: Macrofungal Diversity in Dungus Iwul Nature Reserve and Oil Palm Plantation with Landscape Ecological Approach
Abstrak: As the biggest tropical country in Southeast Asia with the third-largest forest, Indonesia has limited data on macrofungal diversity. The limitation of the data is due to the lack of macrofungal research in high biodiversity locations. One such place is Dungus Iwul Nature Reserve (CADI). The purpose of this study was to determine and examine the macrofungal species diversity caused by changes in landscape structure (fragmentation and land-use change) that occurred in the CADI Fragment and the Oil Palm Plantation of PT Perkebunan Nusantara VIII (PTPN) Matrix, Cigelung, West Java. The sampling method used was opportunistic sampling assisted by line intercept. Macrofungal identification used morphological characters. Macrofungal community ecology analyses were performed in R software. The results showed macrofungal population and diversity in CADI were the highest, followed by PTPN planted in 2004 and 2003, with a significant difference of macrofungal community among the three study locations. The macrofungal community dominance index shows the opposite, with the highest in PTPN 2003 and the lowest in CADI. These results showed changes in macrofungal population and diversity from the conversion in landscape structure. There were eleven possible indicator species in CADI, two species in PTPN 2003, and five species in PTPN 2004., Sebagai negara tropis terbesar di Asia Tenggara dengan hutan terluas ketiga, Indonesia memiliki data keanekaragaman cendawan makroskopis (makrofungi) yang terbatas. Keterbatasan data tersebut disebabkan karena kurangnya penelitian makrofungi di lokasi yang memiliki keanekaragaman hayati tinggi. Salah satunya adalah Cagar Alam Dungus Iwul (CADI) yang merupakan remnant fragment hutan hujan tropis dataran rendah. Tujuan penelitian ini adalah untuk mengetahui dan mengkaji perbandingan keragaman spesies makrofungi yang disebabkan oleh perubahan struktur lanskap (fragmentasi dan alih fungsi lahan) yang terjadi di Fragmen CADI dan Matriks Kebun Kelapa Sawit PT Perkebunan Nusantara VIII (PTPN), Cigelung, Jawa Barat. Metode pengambilan sampel yang digunakan adalah opportunistic sampling dibantu line intercept. Identifikasi makrofungi didasarkan pada karakter morfologi. Analisis ekologi komunitas makrofungi dilakukan dengan menggunakan perangkat lunak R. Hasil penelitian menunjukkan populasi dan keanekaragaman makrofungi pada CADI merupakan yang tertinggi, disusul PTPN tahun penanaman 2004 dan 2003, dengan perbedaan komunitas makrofungi yang signifikan antara ketiga lokasi tersebut. Indeks dominasi komunitas menunjukkan sebaliknya, tertinggi di PTPN 2003 dan terendah di CADI. Hasil ini menunjukkan adanya perubahan populasi dan keragaman makrofungi dari perubahan struktur lanskap. Terdapat sebelas spesies di CADI, dua spesies di PTPN 2003, dan lima spesies di PTPN 2004 yang berpotensi sebagai spesies indikator lokasi masing-masing.
Keyword: macroscopic fungi, R software, remnant fragment

Judul: Keanekaragaman Cendawan Mikoriza Arbuskula (CMA) di Hutan Pantai Ujung Genteng, Sukabumi-Jawa Barat
Abstrak: Indonesia is one of the countries that has a megadiversity of microorganisms and has a large area of coastal forests. However, research on microbial diversity particularly AMF as one of the dominant microbes in a coastal forest ecosystems has not been done extensively. The main objective of this research was to study the diversity and distribution of AMF in coastal forest and to analyse effects of salinity on the fungal and plant community at Coastal Forest Ujung Genteng Cape, Sukabumi - West Java. This research was carried out in two parts: field, green house and laboratorium experimental activities. Field experimental activities were conducted for vegetation analysis, collecting of plant root system, rhizosphere soils from tree and pole phase,. seedling of understorey plants for fungal colonization analysis, isolation and identification of AMF and soil characteristics, include salinity. Green house and laboratorium activities were carried out for isolation, identification and colonization analysis of AMF. Field research location was divided into three zones, first zone was 0 – 70 m distance from coastal area (P), second zone was 71 – 140 m distance from coastal area (T), and third zone was 141 m distance from coastal until forest up to area in the center (H). Twenty three AMF species from 45 plant rizosphere were identified. The fungi belong to 5 species of Acaulospora, 2 species of Gigaspora, 13 species of Glomus, 1 species of Paraglomus and 2 species of Scutellospora. Glomus geosporum was the most dominant AMF in the ecosystem with the value of frequency was 16.49% - 23.67%. Glomus etunicatum, Acaulospora foveata, A. longula, A. scrobiculata, A. tuberculata, and Scutellospora auriglobosa were the AMF that had frequency higher than other species but less than G. geosporum in the field. Results from vegetation analysis indicated that Ujung Genteng Coastal Forest had 68 plant species belonging to 40 families. Dysoxylum parasiticum and Piper cf. baccatum were dominant plants in the ecosystem. The plant community measured at the three zones experimental sites were differed. The similarity index value of the plant community (Is) between coastal P) and center (T) area was 35.42%, between center (T) and forest center (H) was 32.53%, and between coastal edge (P) and forest center (H) was 27.04%. There was no correlation between diversity of plant and diversity of AMF onserved. Diversity of AMF were influenced with all interaction environment factors especially salinity. Two species of AMF had a narrow distribution and found only in a rhizosphere of one plant species . Glomus sp 5. found only in Guettarda speciosa rhizosphere and Glomus sp6. in Salacia sp. rhizosphere. Nineteen species were identified from P zone, 17 species from T zone and 14 species from H zone, with the index diversity values of AMF were 0.73 – 6.64, 0.85 – 4.93 and 1.26 – 4.84, respectively. The salinity at Ujung Genteng Cape was falled in moderate degree with the value of 420 – 1735 μs/cm. The salinity influenced the diversity of AMF and plant community structures. Nineteen species were identified from P zone, 17 species from T zone and 14 species from H zone,
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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