Judul: Kegunaan data anomali suhu muka laut Pasifik (NINO 3.4) untuk prediksi produksi padi di Indonesia
Abstrak: Indonesia as the third largest producer of rice still frequently experience the crop failure due to extreme climate events. The decline of rice production will lead to instability of food security since the rice price will rising and harm poor people who spend a larger portion of their income on rice than do wealthier member of society. This study aims to know the relationship between the rice production at each province in Indonesia with the sea surface temperature anomalies (SSTA) of Nino 3.4, which is one index of ENSO. The correlation between SSTA Nino 3.4 with paddy production ranged between 0.40 to 0.70, which means that the SSTA of Nino 3.4 data has a strong correlation with paddy production data so it can be used as a predictor. The correlation shows that if SSTA Nino 3.4 increasing (El-Nino event), the rice production on January-April declining, while the production on Mei-August and on September-December rising, it is due to the advancing of planting date. But the increase of rice production on Mei-August and on September-December are not as big as the decline on January-April. The provinces that their rice production are influenced by ENSO are the provinces which the rainfall type are monsoon. The best predictor for paddy production is SSTA September one year before. R2 of the prediction model for January-April production >40% which means that the model is good to explain the diversity of production data. While the model for Mei-August and on September-December production are not considered good to explain the diversity of the production data. It is expected that these forecast can be used by the governments and other parties who have interest in establishing a strategy in order to maintain the stability of food security in Indonesia.
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Judul: Optimalization Regional and Global Climate Predictors for Development of Model for Prediction of of Rainy Season over Rice Production in Northern Coast of West Java Province.
Abstrak: Tantangan terbesar di daerah tropis adalah bagaimana mendapatkan model prediksi iklim yang mempunyai akurasi yang tinggi dan konsisten. Iklim Indonesia tidak hanya dipengaruhi oleh iklim lokal tetapi juga sangat dipengaruhi oleh iklim regional dan global seperti aktivitas ElNiño Southern Oscillation (ENSO) yang berada di lautan Pasifik, Southern Oscillation Index (SOI) dan Indian Ocean Dipole Mode (IOD) di lautan India sebelah barat Sumatera serta suhu muka laut (SST) yang belakangan ini diketahui juga mempengaruhi musim di Indonesia. Parameter tersebut telah dijadikan sebagai prediktor model prediksi musim hujan baik secara tunggal maupun gabungan tetapi akurasi hasil luaran model prediksi tersebut masih belum konsisten., In tropical areas of the greatest challenges for climate prediction models is how to develop a model with a high level prediction accuracy due to the complexity of the climate system and the interaction between local conditions, regional and global. Rainfall in Indonesia is influenced by many factor, the main factor is the monsoon circulation. Disturbance in the monsoon often associated with impaired local, regional and global levels. Three phenomena that often affect the rainfall are SST Indonesia, Indian Ocean Dipole Mode and El Nino or La Nina.
Keyword: Seasonal prediction model, Sasonal predictors, PCR, Stepwise regression, Paddy production, Rice Production, Global climate predictors, Linier regression, Global circulation models

Judul: Cycle Hamilton pada Graf Lengkap, Graf Regular, dan Graf 2-Connected 4-Regular Berorder Kurang dari Sepuluh
Abstrak: Suatu graf disebut graf Hamilton apabila graf tersebut memuat cycle Hamilton, yaitu cycle yang melewati setiap vertex tepat satu kali. Menentukan keberadaan cycle Hamilton pada suatu graf dapat menggunakan syarat cukup yang berupa teorema-teorema yang telah diperkenalkan sejak tahun 1950-an. Beberapa syarat cukup yang dibahas dalam karya ilmiah ini adalah syarat cukup yang berhubungan dengan graf lengkap dan graf regular. Suatu graf lengkap berorder 𝑛������ ≥ 3 dan graf r-regular berorder 𝑛������ ≤ 2𝑟������ + 1 merupakan graf Hamilton, Karena kedua graf tersebut memuat cycle Hamilton. Selanjutnya, syarat cukup tersebut digunakan untuk menentukan keberadaan cycle Hamilton pada graf 2-connected 4- regular berorder kurang dari 10.
Keyword: graf Hamilton, graf regular, graf lengkap, graf 2-connected 4-regular