Judul: Beberapa aspek ekologi burung bubut hitam (Centropus nigrorufus cuvier) di RPH Cangkring, BKPH Indramayu KPH Indramayu, Perum Perhutani Unit III Jawa Barat
Abstrak: Status dan pengetahuan kita tentang burung Bubut Hitam (Centropus nigrorufus), salah satu jenis burung endemik Pulau Jawa, sangat minim. Padahal burung ini telah dimasukkan ke dalam data merah IUCN (Red Data Book). Sejauh pengetahuan penulis belum pernah dilakukan penelitian secara mendalam tentang ekologinya. Oleh karena itu, penelitian ini bertujuan untuk menghimpun informasi tentang beberapa aspek ekologi (morfologi, perilaku, jenis makanan, karakteristik sarang, suara dan habitat) C. nigrorufus. Hasil yang diperoleh diharapkan dapat dijadikan dasar bagi penelitian lanjutan dan upaya pelestariannya. Penelitian dilaksanakan di RPH Cangkring, BKPH Indramayu, KPH Indramayu, Perum Perhutani Unit III Jawa Barat dalam rentang waktu antara bulan Desember 1995 hingga bulan Maret 1996. Data yang diambil meliputi data morfologi, perilaku dan vegetasi. Data morfologi diperoleh melalui pengukuran terhadap spesimen-spesimen C. nigrorufus. Pengamatan perilaku dilakukan secara ad libitum yaitu dengan cara mencatat segala hal yang teramati. Data vegetasi diperoleh dengan menggunakan metode garis berpetak. Hasil yang didapat dianalisis secara deskriptif, grafik dan prosentase. Secara umum, C. nigrorufus berwarna hitam kecoklatan. Warna hitam hampir menutupi seluruh permukaan tubuhnya, kecuali beberapa bulu pada bagian sayap berwarna coklat kemerahan. Bulu-bulu di sekitar leher tampak berkilau ungu, sedangkan pada dada terdapat coretan-coretan berwarna putih. Burung muda serupa dengan burung dewasa namun warna bulunya tampak lebih kusam. Anak burung memiliki kulit yang berwarna hitam dan diselimuti oleh bulu-bulu natal yang berwarna putih.
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Judul: Ekologi pecuk hitam (Phalacrocorax sulcirostris Brandt, 1931) di Taman Burung Kota Baru Bandar Kemayoran Jakarta
Abstrak: Kota Baru Bandar Kemayoran (KBBK) terletak di pusat kota Jakarta dan kaya akan avifauna. Di dalam kawasan ini direncanakan pengembangan suatu taman burung, yang selain berfungsi untuk perlindungan juga berfungsi untuk kegiatan rekreasi bersifat mendidik, khususnya rekreasi pengamatan burung (bird watching). Salah satu jenis burung yang menarik untuk diamati yaitu Pecuk Hitam (Phalacrocorax sulcirostris), yang merupakan jenis dominan dan sering dijumpai. Jenis ini mempunyai perilaku khas yang tidak dimiliki oleh spesies lain, yaitu tarian gerakan sayap untuk menarik pasangan (wing waving) dan gerakan membuka sayap membentuk sudut patah di bagian siku berbentuk delta winged disebut wing spreading. Berdasarkan pengamatan awal, populasi Pecuk Hitam tersebar pada hampir semua tipe habitat, meliputi: habitat rawa, habitat mangrove, habitat semak dan habitat waduk buatan, sehingga mudah dijumpai, terutama di waduk buatan. Kondisi ini sangat baik untuk pengembangan rekreasi pengamatan burung (bird watching).
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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