Judul: Interpolasi multi dimensi
Abstrak: Interpolasi adalah metode untuk menaksir nilai data yang tidak ada atau hilang di antara nilai-nilai data yang diberikan. Tujuan penelitian ini adalah untuk mempelajari metode interpolasi dalam dimensi dua, yaitu Bilinear dan mempelajari pengembangan metode interpolasi Bilinear dalam dimensi banyak, serta mengimplementasikan metode interpolasi Multidimensi sampai dengan dimensi tiga. Pada interpolasi dimensi banyak, suatu penduga y(x1, x2,...,x) diperoleh dari suatu grid berdimensi n yang ditabulasikan ke dalam nilai y, dengan n vektor berdimensi satu adalah merupakan nilai-nilai tabulasi dari masing-masing variabel bebas x1, x2,...,n. Dalam hal ini hanya dibatasi untuk interpolasi pada grafik Cartesian, dan hanya dilakukan pada interpolasi berdimensi dua. Untuk interpolasi pada dimensi tiga atau lebih dilakukan generalisasi dari perhitungan tersebut. Dasar pemikiran yang digunakan pada metode Bilinear adalah pemecahan masalah dalam suatu urutan interpolasi berdimensi satu. Interpolasi dilakukan dalam dua arah, yaitu arah x₁ dan x2. Sedangkan untuk interpolasi dalam dimensi banyak, perhitungan yang dilakukan mengikuti metode Bilinear dengan melakukan interpolasi dalam semua arah x; untuk i=1,2,...,n.
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Judul: Interpolasi Multinomial Lagrange di Rn dan Implementasinya dalam MATLAB®
Abstrak: Interpolation is a method to construct a function which goes through a given set of data points. Interpolation is usually implemented in two dimensions. Polynomial Lagrange interpolation is one of formulas that used in R². The purposes of this research are to develop the multinomial Lagrange formula in Rn by reconstructing polynomial Lagrange formula and to build an algorithm of multinomial Lagrange in R³ and its implementation. Systems of linear equations are used as illustration in a process of reconstructing polynomial Lagrange formula. The Vandermonde matrix V is the coefficient matrix of the system. The column vectors of the solution of system are coefficients of interpolation function. A method to reconstruct polynomial Lagrange formula is developed by substituting the rows of Vandermonde matrix V with monomial basis. This method is the basic of construction of multinomial Lagrange interpolation in R". The method is applied by adapting the basis used which is a multinomial basis. An algorithm of multinomial Lagrange interpolation in R³ has been constructed and implemented using MATLAB®. The result of the computation shows that the algorithm is able to work properly.
Keyword: Lagrange interpolation, multinomial basis, Vandermonde matrix

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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