Judul: Sebaran Penyakit dan Gangguan Kesehatan Karang Keras di Perairan Pesisir Timur Pulau Kei Besar, Maluku Tenggara
Abstrak: Penyakit karang merupakan infeksi bakteri, jamur, atau virus yang biasanya diawali oleh menurunnya kondisi kesehatan karang akibat stres atau jenis-jenis gangguan kesehatan karang dari lingkungan perairan maupun biota laut. Penelitian ini bertujuan mengidentifikasi penyakit dan gangguan kesehatan di perairan timur Pulau Kei Besar, Maluku Tenggara. Pengamatan penyakit dan gangguan kesehatan karang keras dilakukan pada 2-18 November 2018 di enam lokasi pengamatan meliputi Ohoifau, Hollat, Fako, Ngefuit Bawah, Weduar, dan Kilwait. Pengamatan dilakukan menggunakan metode Belt Transect dengan klasifikasi penyakit dan gangguan kesehatan karang. Hasil pengamatan menunjukkan terdapat sebelas bentuk pertumbuhan, 19 genera dan 224 koloni karang keras yang terjangkit penyakit karang serta sebelas bentuk pertumbuhan, 46 genera dan 2172 koloni karang keras yang terdampak gangguan kesehatan karang. Terdapat enam jenis penyakit karang dengan penyakit yang paling mendominasi adalah Focal Bleaching (FBL) serta sembilan jenis gangguan kesehatan karang dengan gangguan kesehatan yang paling mendominasi adalah Sediment Damage (SD).
Keyword: penyakit karang, gangguan kesehatan karang, belt transect, sediment damage, focal bleaching, coral disease, compromised health

Judul: Coral Reef Health Index in East Coastal Waters of Kei Besar Island, Southeast Maluku
Abstrak: Kei Besar Island has the potential of coral reef resources that have not been explored and utilized optimally. The lives of the people of Kei Besar Island depend on marine resources, especially from coral reef ecosystems. This causes the need for management of coral reef ecosystems by looking at the health conditions of coral reefs. The purpose of this study was to examine the distribution of the reef health index in the eastern coastal waters of Kei Besar Island. Data collection was carried out on 3-18 November 2018 in the coastal waters of East Kei Besar with 6 location points, namely Ohoifau, Hollat, Fako, Ngufit Bawah, Weduar, and Kilwait at a depth of 3 meters using the Point Intercept Transect (PIT) and Underwater Visual Census methods. (UVC). The results showed that the East coast of Kei Besar has a fairly well-maintained condition of the coral reef ecosystem. This can be seen from the condition of coral reef cover (hard coral) which is classified as good. The distribution of coral reef health index values in the coastal waters of East Kei Besar shows that the waters are classified as good at a value of 5-6. The Hollat location has the lowest coral health value because at this location it is affected by a decrease in ship anchors and high algal cover. This research is expected to be useful in providing information to the local community and government in an effort to improve coral reef resources., Pulau Kei Besar memiliki potensi sumberdaya terumbu karang yang belum tereksplorasi dan dimanfaatkan dengan optimal. Kehidupan masyarakat Pulau Kei Besar bergantung dengan sumberdaya laut terutama dari ekosistem terumbu karang. Hal ini menyebabkan perlu adanya pengelolaan ekositem terumbu karang dengan melihat kondisi kesehatan terumbu karang. Tujuan penelitian ini adalah untuk melihat persebaran indeks kesehatan terumbu di perairan pesisir Timur Pulau Kei Besar. Pengambilan data dilaksanakan pada tanggal 3 – 18 November 2018 di perairan pesisir Timur Kei Besar dengan 6 titik lokasi yaitu Ohoifau, Hollat, Fako, Ngufit bawah, Weduar, dan Kilwait pada kedalaman 3 meter menggunakan metode Point Intercept Transect (PIT) dan Underwater Visual Census (UVC). Hasil penelitian menunjukkan pesisir Timur Kei Besar memiliki kondisi ekosistem terumbu karang yang cukup terjaga. Hal ini terlihat dari kondisi tutupan terumbu karang (hard coral) tergolong baik. Sebaran nilai indeks kesehatan terumbu karang di perairan pesisir Timur Kei Besar menunjukkan bahwa perairan tersebut tergolong baik berada pada nilai 5-6. Lokasi Hollat memiliki nilai kesehatan karang terendah karena pada lokasi ini dipengaruhi oleh penurunan jangkar kapal dan tingginya tutupan alga. Penelitian ini diharapkan dapat bermanfaat dalam memberikan informasi kepada masyarakat dan pemerintah setempat dalam upaya meningkatkan sumberdaya terumbu karang.
Keyword: coral reef health index, coral reefs, point intercept transect, underwater visual census

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