Judul: Analisis Variabilitas Iklim Terhadap Kondisi Terumbu Karang di TWP Kapoposang – Kepulauan Spermonde Selat Makassar
Abstrak: Variabilitas iklim global dapat ditandai dengan dinamika parameter klimatologi-oseanografi dan dapat mempengaruhi kondisi terumbu karang. Untuk mempelajari dampak variabilitas iklim, kami menganalisis (1) karakteristik parameter fisik klimatologi-oseanografi dan korelasinya dengan El Niño–Southern Oscillation (ENSO); (2) parameter biokimia oseanografi (klorofil, nitrat, dan fosfat) dan korelasinya dengan ENSO; dan (3) variabilitas iklim (ENSO) dan kondisi terumbu karang di Taman Wisata Bahari Kapoposang Pulau Spermonde. Kumpulan data tutupan terumbu karang diperoleh dari Pusat Penelitian Kelautan Kementerian Kelautan dan Perikanan (KKP) Republik Indonesia, digabungkan dengan analisis citra Landsat dari tahun 2000 hingga 2020, dan data sekunder lainnya dari berbagai sumber. (Misalnya, MoMAF, Universitas Hasanuddin, artikel ilmiah). Berdasarkan hasil penelitian, secara umum terlihat bahwa peningkatan konsentrasi nitrat di setiap musim tidak memberikan pengaruh signifikan pada peningkatan konsentrasi klorofil di kawasan TWP Kapoposang. Sebaliknya terjadi peningkatan konsentrasi fosfat yang cenderung memberikan dampak yang lebih besar terhadap peningkatan konsentrasi klorofil di musim Timur dan Barat. Terjadinya fenomena ENSO memberikan dampak pada variabilitas parameter biologi-kimiawi di lokasi studi. Hasil koefisien korelasi tahunan dan bulanan antara ENSO dan Klorofil-a menunjukan hubungan lemah hingga kuat. Hasil koefisien korelasi tahunan dan bulanan antara ENSO dan NO3 menunjukan hubungan lemah, sedangkan ENSO dan PO4 menunjukan hubungan sangat lemah hingga kuat (tahunan dan bulanan). Variasi NO3 (mmol/m3), PO4 (mmol/m3) dan Chlorophylla berasosiasi dengan variabilitas interannual ENSO. Analisis korelasi menunjukkan bahwa fenomena ENSO menyebabkan variabilitas parameter klimatologi-oseanografi. Parameter klimatologi seperti curah hujan tahunan menunjukkan hubungan yang kuat dengan ENSO (-0,60) dan curah hujan bulanan dengan ENSO (-0,69). Suhu tahunan memiliki hubungan yang lemah (0,20) sedangkan suhu bulanan sangat kuat (0,41). Parameter oseanografi seperti Suhu Permukaan Laut (SST) tahunan memiliki hubungan yang sangat lemah dengan ENSO (-0,08), dan hubungan yang lemah antara SST bulanan dan ENSO (- 0,27). Salinitas tahunan memiliki hubungan yang lemah dengan ENSO (0,39) tetapi hubungan yang kuat antara salinitas bulanan dan ENSO (0,66). Analisis statistik antara SST Nino 3.4 dan SPL lokal dengan tutupan terumbu karang menunjukkan arah koefisien korelasi positif.
Keyword: ENSO, climatological-oceanographic parameters, Kapoposang Marine Tourism Park, coral reefs

Judul: Pengaruh Faktor Pengendali Variabilitas Iklim terhadap Suhu Permukaan Laut dan Klorofil-a di Perairan Pulau Natuna Kepulauan Riau
Abstrak: Faktor pengendali variabilitas iklim memengaruhi iklim laut. Perairan Pulau Natuna yang terletak di tengah Laut Natuna Utara mengalami anomali iklim yang dipengaruhi oleh fenomena Monsun, ENSO, dan IOD. Penelitian bertujuan untuk menganalisis suhu permukaan laut (SPL) dan klorofil-a di perairan Pulau Natuna saat iklim normal, ENSO dan IOD serta menganalisis hubungan korelasi ENSO dan IOD terhadap suhu permukaan laut dan konsentrasi klorofil-a. Penelitian dilakukan secara spasial dengan melakukan pemetaan permusim dengan data empat rerata triwulan; Desember-Januari Februari (DJF), Maret-April-Mei (MAM), Juni-Juli-Agustus (JJA) dan September-Oktober-November (SON) untuk SPL dan klorofil-a saat fenomena ENSO dan IOD. Penelitian secara temporal disajikan dengan data time series dan hasil korelasi antara data SPL dan klorofil-a terhadap data ONI dan DMI. Hasil penelitian menunjukkan korelasi negatif antara SPL dan klorofil-a sebesar -0.73. ENSO dan IOD memberikan pengaruh yang berbeda terhadap perairan Pulau Natuna pada setiap musim monsun. Di perairan Pulau Natuna korelasi positif antara ONI dan SPL terkuat pada bulan DJF (0.47), sementara korelasi negatif dengan klorofil-a terkuat pada bulan SON (-0.68). DMI menunjukkan korelasi negatif (-0.42) dengan SPL selama bulan JJA dan juga korelasi negatif dengan klorofil-a di perairan Pulau Natuna selama musim JJA (-0.57) dan SON (-0.67)., Climate variability significantly influence the marine climates. The waters of Natuna Island, in the middle of North Natuna Sea experiences climate anomalies influenced by Monsoons, ENSO, and IOD. This study aims to analyze sea surface temperature (SST) and chlorophyll-a in the waters of Natuna Island during normal climate, ENSO and IOD, and to analyze the correlation between ENSO and IOD with SST and chlorophyll-a concentration. The study was conducted spatially by mapping four quarterly averages seasonal data; December-January-February (DJF), March-April-May (MAM), June-July-August (JJA), and September-October-November (SON) for SST and chlorophyll-a during ENSO and IOD phenomenon. Temporally, the study presented with time series graphs and the correlation results between SST and chlorophyll-a data with ONI and DMI data. The results showed a negative correlation between SST and chlorophyll-a of -0.73. ENSO and IOD have different influences on the waters of Natuna Island in each monsoon season. In the waters of Natuna Island, the positive correlation between ONI and SST is strongest during the DJF months (0.47), while the negative correlation with chlorophyll-a is strongest during the SON months (-0.68). DMI showed negative correlation (-0.42) with SST during JJA season and also negative correlation with chlorophyll-a during JJA (-0.57) and SON (-0.67).
Keyword: klorofil-a, ENSO, IOD, Monsun, SPL

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