Judul: Perbandingan Metode Diskretisasi Dalam Model Regresi Logistik (Studi Kasus : Pembentukan Model Penskoran Kredit Bank X)
Abstrak: The number of KPR customers of bank X decreased since February 2012 until August 2012. Logistic regression which is used in credit scoring model is not only able to identify the significance factors but also to know the scoring value in each category of explanatory variable. The data used in credit scoring model must be categorical data. Continuous data needs to be discretized in order to get categorical data. Discretization process can use chimerge method (model I) and equal with interval method (model II). Based on logistic regression, the factors that affect the respon are sex, employment status, education, occupation, age, and income. Correct classification table, shows that model I is better to classify than model II, therefore the scorecard is made based on model I.
Keyword: scorecard, logistic regression, equal with interval, credit scoring, chimerge

Judul: Kajian Perbandingan Model Credit Scoring Terhadap Data Numerik Dan Tata Kategorik Menggunakan Regresi Logistik
Abstrak: Model scoring diperlukan oleh berbagai institusi dan perusahaan untuk meningkatkan profitabilitas mereka. Model regresi logistik merupakan salah satu teknik yang sering digunakan. Penggunaan teknik ini pun menjadi populer karena memberikan kemudahan dalam interpretasi dan ketersediaan software yang dapat menanganinya. Permasalahan yang sering muncul dalam penyusunan model scoring ini adalah bagaimana memilih peubah penjelas yang akan dimasukkan ke model dan mampu mencerminkan keadaan finansial debitor. Selain itu dalam pembentukkan model terganggu dengan keberadaan data outlier dan data yang hilang (missing) pada kasus-kasus tertentu. Data-data yang ada saat ini sangat rentan terhadap noise, missing value, dan tidak konsisten. Salah satu teknik yang digunakan untuk menanganinya adalah dengan transformasi data dan reduksi data. Oleh karena itu penelitian dilakukan untuk membandingkan model scoring yang dibangun oleh nilai asli peubah penjelasnya dengan model scoring yang dibangun oleh nilai hasil diskretisasi peubah penjelasnya menggunakan metode regresi logistik. Berdasarkan perbandingannya tersebut model yang peubah penjelasnya dibangun oleh nilai hasil diskretisasi memberikan peluang untuk menghasilkan model dengan performans yang lebih baik.
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Judul: Application of phycocyanin from microalgae Spirulina platensis as light harvesting in anatase TiO2 nanoparticle solar cell.
Abstrak: The dye sensitized solar cell (DSSC) has been assemblied used hybrid titanium oxide (TiO2) film/phycocyanin. The TiO2 film was synthesized by sol gel method with titanium chlorida (TiCl4) as precursor by hydrolysis used sulfuric acid (H2SO4). Furthermore, it calcinated for 2,5 hours in variation of annealing temperature (400oC, 600oC, 800oC, dan 1000oC). In XRD patterns exhibited which annealing temperature at 400oC to 800oC were anatase phase all. When annealed at temperature 1000oC, it caused phase transformation from anatase to rutile. The crystals size according to XRD patterns were 13,75 nm, 20,79 nm, 25,25 nm, 48,88 nm and particle size from SEM images were 43,06 nm, 44,91 nm dan 64,99 nm, 80,40 nm, respectively. The crystals and particle size increased with annealing temperature. The film thickness influenced material absorption. The optical measurement of TiO2 film and TiO2/phycocyanin hybrid film used UV-Vis spectrophotometer. Additional phycocyanin caused peak width of absorbed region from ultraviolet to visible region. The band gap energy of TiO2 can be calculated using the cut off wavelength obtained from the absorbance spectrum of a nanoparticles TiO2 films. Based on intersection between linear and energy (hv) axis. In this study just limited for anatase phase. It was caused anatase band gap is wider than rutile phase. That’s meaningful for solar cell application such as dye sensitized solar cell (DSSC). The absorption coefficient average at difference annealing temperature such as at 400oC, 600oC, 800oC were 8,1600x102, 1,7535x103 and 4,0154x102, where α < 104 include to direct transition. Band gap energy 400oC, 600oC, 800oC were 3,79 eV, 3,59 eV, and 3,35 eV, respectively. Based on this result, exhibition that band gap energy of TiO2 semiconductor film decreased with increasing annealing temperature. Spirulina platensis was cultivated in technical modification (Hastuti) with aeration under light intensity about 3000 lux. The cell density (stationer phase) for eighth day which OD value was more than 0,5. It means, the culture can be harvested. In 80 liters Spirulina platensis culture have been produced biomass dry about 10,46 gram and extracted phycocyanin in dry powders was 5,50 gram. The phycocyanin absorption spectrum at the wavelength of 619,36 nm (visible region) which had relaxation energy was 2,945 eV. The emission peak at the wavelength of 708,55 nm with relaxation energy about 2,793 eV. The Stokes shift based on difference energy absorption and emission calculated about 0,152 eV. Both of this showed phycocyanin can absorbed and radiated the sun light which received. This choice characteristic pigment was a good one related to sensitizer in solar cell application. Integration between light harvesting protein and TiO2 semiconductor surface had important role in improving of output as solar cell materials. The presence of carboxylate group (-COOH) made pigment be more efficient was due to anchored to the surface of TiO2 ampoter. The phycocyanin pigment had carboxylate group which reacted with TiO2 surface formed ester. The carboxylate group increased of dye electronics couple from excited state (p anti bonding orbital) to semiconductor acceptor state (TiO2 conduction band). The samples which made based on annealing temperature variation formed be solar cell respectively. Furthermore, cells be assembled for
Keyword: anatase, dye sensitized solar cell, efficiency, gap energy, phycocyanin