Judul: Analisis Degradasi Fungsi Ekologi Mangrove sebagai Habitat Makrozoobentos dan Pengelolaannya di Pantai Angke Kapuk, Jakarta Utara
Abstrak: Ekosistem mangrove merupakan sumberdaya alam yang memiliki banyak manfaat ekologi bagi ekosistem pesisir, diantaranya adalah sebagai habitat dan sumber pakan bagi kehidupan biota darat maupun laut. Salah satu wilayah Indonesia yang memiliki kawasan hutan mangrove yang cukup luas adalah di Propinsi DKI Jakarta bagian utara yakni kawasan pantai Angke Kapuk yang memiliki sabuk hijau seluas 327,70 ha dan tersebar di beberapa wilayah (BKSDA DKI Jakarta, 2003). Kawasan mangrove di Angke Kapuk berperan penting dalam pelestarian ekosistem karena menjadi suaka bagi sejumlah spesies yang menempatinya salah satunya adalah makrozoobentos. Seiring dengan perkembangan pembangunan kota, mangrove menjadi salah satu sumberdaya pesisir yang rentan oleh degradasi lingkungan seperti pariwisata, perikanan, dan industri. Tujuan penelitian ini adalah untuk menganalisis fungsi ekologi mangrove sebagai habitat makrozoobentos di kawasan Pantai Angke Kapuk, menentukan status tingkat kerusakan mangrove dan merekomendasikan pengelolaan ekosistem mangrove yang berkelanjutan di kawasan Pantai Angke Kapuk. Penelitian ini dilaksanakan pada bulan Juni 2013 dan Maret 2014 pada enam stasiun berbeda berdasarkan keterwakilan kondisi lokasi penelitian. Pengumpulan data terdiri dari pengumpulan data makrozoobentos dan pengukuran beberapa parameter kualitas air yaitu kekeruhan, DO, COD, BOD, salinitas, pH, nitrat (NO3-N), nitrit (NO2-N), orto fosfat (PO4-P), dan padatan tersuspensi (TSS). Hasil penelitian menunjukan bahwa sebagai habitat makrozoobentos, kawasan mangrove di pantai Angke Kapuk telah mengalami degradasi fungsi ekologis dan status mangrove di pantai Angke Kapuk telah masuk dalam kategori rusak berdasarkan kriteria baku kerusakan mangrove Kepmen LH No 201 Tahun 2004 kerapatan mangrove <1000 pohon/ha dan penutupan <50%, sehingga upaya rehabilitasi sangat perlu dilakukan dengan melibatkan peran masyarakat dan sektor pengelola terkait dalam pengelolaan kawasan mangrove yang berkelanjutan. Perbaikan habitat dapat dilakukan dengan membersihkan sampah dan mengangkutan sampah keluar dari kawasan mangrove, terutama pada kelompok stasiun A yang memiliki kondisi mangrove paling rusak dan paling banyak menerima tekanan lingkungan, begitu juga dengan kelompok stasiun B yang sangat berpotensi mengalami degradasi fungsi ekologi akibat tekanan pembangunan yang besar pada kawasan mangrove di kelompok ini, kemudian dilakukan penanaman vegetasi mangrove pada site yang telah siap untuk ditanam.
Keyword: Angke Kapuk, degradasi, makrozoobentos, mangrove, pengelolaan

Judul: Analysis of Mangrove Damage and Rehabilitation Steps in the Angke Kapuk Protected Forest, North Jakarta
Abstrak: Ekosistem mangrove merupakan salah satu habitat alami pada kawasan pesisir yang sangat rentan terhadap ancaman alam baik dari darat maupun laut. Selain disebabkan oleh alam, ancaman terhadap ekosistem mangrove juga dapat disebabkan oleh kegiatan manusia. Penelitian ini bertujuan untuk menganalisis tingkat kerusakan mangrove dan potensi rehabilitasi mangrove di Hutan Lindung Angke Kapuk, Jakarta Utara. Penelitian ini dilaksanakan pada bulan Desember 2021 hingga Januari 2022 dengan lokasi penelitian terdiri dari tiga stasiun yang meliputi tiga tipe yaitu teluk, muara sungai, dan pantai reklamasi. Kerapatan dan penutupan mangrove di Angke Kapuk tergolong dalam kriteria rendah, kecuali stasiun 1 yang memiliki kerapatan sangat tinggi dan penutupan mangrove dalam kriteria rendah. Kondisi ini mengakibatkan nilai indeks kesehatan mangrove menjadi sedang pada stasiun 1, sedangkan stasiun 2 dan 3 tergolong kategori rendah. Indeks kualitas lingkungan pada ketiga stasiun tergolong kedalam kategori tinggi. Berdasarkan nilai kedua indeks tersebut, tingkat kerusakan pertumbuhan mangrove tergolong tinggi dan kerusakan lingkungan mangrove tergolong rendah dan diketahui matriks rehabilitasi mangrove dengan strategi replantasi. Strategi replantasi tersebut mempertimbangkan zonasi dalam penentuan jenis mangrove yang ditanam., Mangrove , one of the natural ecosystems in coastal areas is very vulnerable to n threats both from land and sea. Besides being caused by nature, threats to mangrove ecosystems can also be caused by human activities. This study aims to analyze the level of damage to mangroves and the potential for mangrove rehabilitation in the Angke Kapuk Protection Forest, North Jakarta. This research was carried out from December 2021 to January 2022 with research locations consisted of three stations covering three types, namely bays, river mouths, and reclamation beaches. The density and cover of mangroves in Angke Kapuk are classified as low criteria, except for station 1 which has a very high density and mangrove cover is in the low criteria. This condition causes the mangrove health index value to be moderate at station 1, while stations 2 and 3 are in the low category. The environmental quality index at the three stations belongs to the high category. Based on the values of these two indices, the level of damage to mangrove growth is classified as high and environmental damage to mangroves is classified as low and it is known that the mangrove rehabilitation matrix with a replantation strategy. The replantation strategy considers zoning in determining the type of mangrove to be planted
Keyword: kesehatan mangrove, kualitas lingkungan, mangrove, rehabilitasi, environmental quality, mangrove health, rehabilitation, mangroves

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