Judul: Penggabungan Ekstraksi Fitur menggunakan Early Integration pada Klasifikasi Fragmen Metagenome
Abstrak: Analisis metagenom merupakan salah satu cabang ilmu ekologi mikroba yang berkembang begitu pesat dalam beberapa tahun terakhir. Ilmu metagenom mengacu kepada akses secara langsung konten genetik seluruh komunitas organisme pada sampel lingkungan yang diambil. Sudah banyak penelitian dilakukan dalam bidang ini, terutama pada pengelompokan berdasarkan komposisi, dengan berlandaskan fakta bahwa dua organisme yang sejenis memiliki komposisi nukleotida yang mirip. Pada penelitian ini, digunakan k-mers, Characterization Vector (CV) dan Gray Level Co-occurrence Matrix (GLCM) sebagai ekstraksi fitur dikombinasikan dengan early integration sebagai metode penggabungan fitur. Support Vector Machine dipilih sebagai mesin klasifikasi. Hasil penelitian menunjukkan bahwa penggabungan di antara ketiga ekstraksi fitur tidak meningkatkan akurasi secara signifikan. Nilai akurasi untuk panjang fragmen 3 Kbp untuk k-mers adalah 89.513%, mersCV 89.506%, mersGLCM 89.427%. Disimpulkan bahwa ekstraksi fitur CV dan GLCM kurang baik dalam memisahkan fragmen ke dalam kelasnya masing-masing.
Keyword: fragmen metageno, ekstraksi fitur, early integration

Judul: Klasifikasi Fragmen Metagenom Menggunakan Metode SVM dan Fast Correlation Based Filter sebagai Penyeleksi Fitur
Abstrak: Bioinformatika memiliki banyak bidang kajian penting dan terus berkembang, salah satunya adalah analisis metagenom. Metagenom merupakan materi genetik yang diperoleh dari sampel yang langsung diambil dari lingkungan tanpa budidaya di laboratorium. Untuk mengklasifikasikan fragmen metagenom ke dalam tingkat taksonomi yang berbeda perlu dilakukan proses binning. Pada penelitian ini dilakukan proses binning dengan pendekatan komposisi menggunakan metode supervised learning. Proses klasifikasi dilakukan dengan menggunakan Support Vector Machine (SVM) sebagai classifier, perhitungan frekuensi k-mers untuk mengekstraksi fitur, dan Fast Correlation Based Filter (FCBF) sebagai penyeleksi fitur. Pada proses seleksi fitur, jumlah fitur yang terseleksi ditentukan oleh nilai threshold. Dari penelitian ini akurasi hasil klasifikasi SVM dengan seleksi fitur berkisar antara 79.13% sampai 96.68% untuk 3-mers, sedangkan jika menggunakan 4-mers akurasi berkisar antara 83.59% sampai 99.35%.
Keyword: metagenom, binning, k-mers, feature selection, fast correlation based filter, threshold, SVM

Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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