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.....
Keyword: 

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: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite