Judul: Penerapan analisis artificial neural networks (ANN) dalam pengelompokkan ekstrak daun jati Belanda (Guazuma ulmifolia Lamk.)
Abstrak: Penelitian bertujuan untuk mengidentifikasi keberadaan gugus fungsi ekstrak Flavonoid N Butanol, Flavonoid Etil Asetat, Kloroform, Heksana, Triterpenoid dan Steroid dari daun Jati Belanda (Guazuma Ulmifolia Lamk.). Disamping itu, penelitian ini juga bertujuan untuk mencari model yang dapat mengelompokkan keenan jenis ekstrak dan sekaligus mencari pola hubungan antara aktivitas enzim lipase murni dari ekstrak tersebut dengan pola spektra IR-nya.
Keyword: Artificial Neural Networks, Quasi-Newton, Analisis Komponen Utama

Judul: Pemodelan Klasifikasi Obat Bahan Alam dengan Metode Partial Least Squares Discriminant Analysis (Studi Kasus: Reflektans Daun Jati Belanda).
Abstrak: Umur memengaruhi kadar senyawa aktif di dalam tumbuhan. Apabila komponen senyawa aktif yang terkandung dalam tumbuhan telah dipastikan keseragamannya, obat bahan alam terjamin keamanan dan khasiatnya. Salah satu cara untuk mengidentifikasi komponen senyawa aktif dari ekstrak tumbuhan secara cepat dan efisien adalah dengan menggunakan spektrofotometer reflektans sinar tampak yang dikombinasikan dengan analisis multivariat. Analisis yang digunakan dalam penelitian ini yaitu Partial Least Squares Discriminant Analysis (PLS-DA) karena metode ini tepat digunakan pada data metabolomik yang cenderung berdimensi tinggi, terdapat data hilang, derau, dan multikolinearitas. Kombinasi keduanya digunakan untuk mengklasifikasikan daun jati belanda (Guazuma ulmifolia Lamk.) berumur satu bulan, dua bulan, dan tiga bulan yang digunakan sebagai peubah respon. Nilai akurasi yang diperoleh dari model PLSDA dalam melakukan klasifikasi dan prediksi masing-masing sebesar 95% dan 86.67%. Selain itu, masih terdapat misklasifikasi yang disebabkan oleh pola spektrum dan nilai rataan reflektansnya.
Keyword: daun jati belanda, klasifikasi, PLS-DA, spektrofotometer reflektans sinar tampak

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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