Judul: Analisis data percobaan faktorial 4x4 dengan perlakuan-perlakuan berpasangan terhadap blanko (Plasebo) dengan metode doolittle dipersingkat
Abstrak: Tujuan dari telaahan statistika ini adalah ingin meli- hat efisiensı dari percobaan yang dilakukan (terutama terha- dap prosedur pengelompokan yang digunakan), serta mencari analısıs yang sesuai dengan keadaan data yang telah diperoleh.....
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Judul: The application of LASSO method in determination of main effect and significant interaction in fractional factorial experiment results
Abstrak: Analisis regresi dapat diterapkan pada berbagai macam data termasuk pada data hasil percobaan. Rancangan Faktorial Pecahan (RFP) banyak digunakan untuk mengatasi masalah biaya pada percobaan yang melibatkan banyak faktor. Penentuan pengaruh utama maupun interaksi yang signifikan adalah salah satu tujuan dari suatu percobaan faktorial. Namun, penentuan pengaruh utama maupun interaksi yang signifikan pada RFP cukup rumit, karena jumlah observasi lebih sedikit daripada pengaruh utama maupun interaksi yang akan diduga pengaruhnya. Adanya pembauran juga menjadi masalah pada RFP. Pada penelitian ini digunakan Metode Least Absolute Shrinkage and Selection Operator (LASSO) dengan mempertimbangkan prinsip heredity, hierarchy, dan sparsity untuk menyelesaikan masalah pada RFP. Hasil penelitian menunjukkan bahwa hasil dari metode LASSO pada data simulasi hampir sama dengan pengaruh utama maupun interaksi yang sengaja ditentukan berpengaruh signifikan. Untuk data percobaan real juga menghasilkan hasil yang hampir sama dengan metode lain untuk data yang sama, Regression analysis can be applied to a wide variety of data, including the experimental data. Fractional Factorial Design (FFD) is widely used to address cost issues in the experiment involving many factors. Effect determination of the main effect as well as a significant interaction was one of the goals of a factorial experiment. However, it is quite complicated, because the number of observations less than the main effect and the interaction that will supposedly influence. The existence of confounding is also an issue in the FFD. The method used in this study are Least Absolute Shrinkage and Selection Operator (LASSO) by considering the principle of heredity, hierarchy, and sparsity to solve problems in the FFD. The results showed that simulated data is almost the same in LASSO method as the main effect as well as the interaction that deliberately determined to have a significant effect. Real experimental data also yield almost the same results with other methods for the same data. Keywords: Determination of significant effect, FFD, LAR Algorithm, LASSO.
Keyword: Algoritma LAR, LASSO, Penentuan pengaruh signifikan, RFP

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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