Judul: Analisis biplot untuk memetakan mutu sekolah yang sesuai  dengan nilai ujian nasional
Abstrak: Mutu sekolah dalam bidang akademik biasanya dikaitkan dengan nilai Ujian Nasional, sedangkan nilai tersebut hanya digunakan sebagai acuan untuk menentukan kelulusan siswa. Sebagai tindak lanjut, nilai Ujian Nasional dapat dianalisis untuk mendapatkan informasi lain dalam hubungannya dengan peningkatan mutu sekolah. Pemetaan mutu sekolah merupakan suatu proses untuk memperoleh gambaran mutu sekolah yang sesuai dengan nilai Ujian Nasional dan peubahpeubah yang mempengaruhinya. Dalam statistika dikenal suatu analisis data yang menganalisis secara serempak peubah amatan lebih dari satu, yaitu Analisis Peubah Ganda. Salah satu teknik yang digunakan adalah pereduksian dimensi data peubah ganda. Analisis Peubah Ganda yang menggunakan teknik ini antara lain ialah Analisis Komponen Utama dan Analisis Biplot.
Keyword: 

Judul: Analisis Biplot untuk Memetakan Provinsi Berdasarkan Prestasi Mahasiswa TPB IPB dan Nilai Ujian Nasional
Abstrak: Quality description of schools in academic field is supposed to be seen from attainment of national exam (UN) score. Students’ achievement in college can be described with acquisition of high GPA. Provincial mapping can be used to obtain a description of its position in accordance with the achievement of UN score and students’ achievement in college. The data used in this study for provincial mapping are TPB IPB students’ achievement in 2007/2008 academic year. Provincial mapping is conducted by using biplot analysis. Preliminary data exploration is conducted by using boxplot, GPA-UN plot, and Pearson’s correlation matrix. The correlation between UN score and GPA, which is 0.41**, is highly significant but not large enough to measure successfulness in college. In this study, biplot analysis can explain 74.56% of data variability. Based on the proximity among provinces and the interrelationship of provinces with variables used, these provinces can be grouped into nine groups. This grouping is expected to provide informations on advantages and disadvantages of each province in order to improve its educational quality.
Keyword: 

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.
Keyword: