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: Study of Economic Value and Sustainability of Mangrove Ecosystem Management in Angke Kapuk Nature Tourism Park
Abstrak: Konversi lahan mangrove menjadi peruntukkan lain kerap kali terjadi di Indonesia, tidak terkecuali di Provinsi DKI Jakarta. Salah satu lahan mangrove yang berhasil dipertahankan sebagai lokasi ekowisata oleh Pemerintah Provinsi DKI Jakarta adalah Taman Wisata Alam (TWA) Angke Kapuk. Selain mempertahankan fungsi ekosistem mangrove sebagai penyedia jasa lingkungan, keberadaan TWA Angke Kapuk juga memiliki banyak kegunaan baik secara langsung maupun tidak langsung bagi wisatawan dan masyarakat sekitar. Penelitian ini bertujuan untuk (1) mengkaji kondisi ekosistem mangrove di TWA Angke Kapuk, (2) mengestimasi nilai ekonomi total dari ekosistem mangrove di TWA Angke Kapuk, (3) menganalisis status keberlanjutan ekosistem mangrove di TWA Angke Kapuk. Metode penelitian yang digunakan adalah studi kasus, sedangkan metode analisis yang digunakan adalah analisis deskriptif kuantitatif, valuasi ekonomi, Travel Cost Method (TCM), dan Rapid Appraisal of Mangrove Forest (Rap_Mforest). Hasil penelitian menunjukkan kondisi ekosistem mangrove TWA Angke Kapuk lebih baik setelah adanya rehabilitasi dilihat dari pertambahan luas tutupan vegetasi, jenis, kerapatan, serta perubahan pemanfaatan ekosistem mangrove. Hasil estimasi nilai ekonomi total ekosistem mangrove TWA Angke Kapuk yaitu sebesar Rp17.943.600.572/tahun atau Rp179.759.573/ha/tahun. Status keberlanjutan ekosistem mangrove TWA Angke Kapuk memiliki status kurang berkelanjutan untuk dimensi ekologi (50,23), sedangkan untuk dimensi ekonomi (64,83), dimensi sosial (56,95), dan dimensi kelembagaan (53,75) memiliki status cukup berkelanjutan. Pengelolaan TWA Angke Kapuk perlu ditingkatkan agar ekosistem mangrove dapat mencapai status keberlanjutan baik., Conversion of mangrove land into other uses often occurs in Indonesia, including in Special Capital Region of Jakarta. One of the mangrove lands that has been successfully preserved as an ecotourism area by the Jakarta Provincial Government is the Angke Kapuk Nature Tourism Park (NTP). Besides to maintain its function as an environmental service providers, the existence of Angke Kapuk NTP is also directly and indirectly useful for tourists and the surrounding community. This research aims to (1) examine the condition of mangrove ecosystem in Angke Kapuk NTP, (2) estimate the total economic value of mangrove ecosystem in Angke Kapuk NTP, and (3) analyze the sustainability status of mangrove ecosystem in Angke Kapuk NTP. The research method used in this research is case study, while the analytical methods used are quantitative descriptive analysis, economic valuation, Travel Cost Method (TCM), and Rapid Appraisal of Mangrove Forest (Rap_Mforest). The results of the research showed that the condition of mangrove ecosystem after rehabilitation is in a better condition, which can be seen from the improvement in the area of vegetation cover, type, density, and appropriate utilization of mangrove ecosystem in Angke Kapuk NTP. The total economic value of mangrove ecosystem in Angke Kapuk NTP is Rp17.943.600.572 per year or Rp179.759.573 per hectare per year. The sustainability analysis of mangrove ecosystem in Angke Kapuk NTP are classified as less sustainable for the ecological dimension (50,23), while for other dimensions which consist of the economic dimension (64,83), the social dimension (56,95), and the institutional dimension (53,75) are classified as quite sustainable. Therefore, the management of Angke Kapuk NTP needs to be improved in order to obtain a good sustainability status of the mangrove ecosystem.
Keyword: konversi lahan mangrove, Rap_Mforest, status keberlanjutan, TCM, valuasi ekonomi

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