Judul: Perbandingan Oversampling Duplikasi Terhadap Oversampling Acak pada Algoritme K-Nearest Neighbour untuk Kasus Imbalanced Data
Abstrak: Imbalanced class can give negative effect, especially the tendency of the data classes becomes imbalanced. It causes the data will be more inclined to the majority class composition and ignore the minority class. But, minority class sometimes has important information even more difficult to predict than the majority class. In addition, it can also decrease the classifier performance of imbalanced class. The solution will be done by modifying the dataset using duplication oversampling and random oversampling. In this study, a comparison will be made between the random oversampling and duplication oversampling. In this study, we use k-nearest neighbour as the clasifier. The results show that duplication oversampling has better performance than random oversampling, but random oversampling. However, the f-measure of random oversampling is slightly different compared to that of the duplication oversampling
Keyword: Oversampling., K-Nearest Neighbour, Bogor Agricultural University (IPB), Imbalanced data, F-measure

Judul: Klasifikasi Debitur Kartu Kredit Menggunakan Algoritme K-Nearest Neighbor untuk Kasus Imbalanced Data
Abstrak: Data is said to suffer the class imbalanced problem when the class distribution are highly imbalance. In this case, minority class is more difficult to predict then the majority class. Though the minority class sometime has important information. In this paper, classification analysis of credit card debtors is conducted by using k-nearest neighbor that can classify debtors into two categories, good or bad. Analysis of a prospective debtor is essential to minimize credit risk. One approach taken to overcome imbalanced data problems is to modify instance distribution using oversampling and undersampling method. The evaluation is conducted by comparing the value of parameter k, accuracy, precision, recall, and F-measure. The evaluation results show that oversampling technique gives the best result of 96.24% with k = 3, 99.23% recall with k = 2, 95.21% precision with k = 1, and 96.30% F-measure with k = 3.
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Judul: Pembuatan Film Tipis Cu2ZnSnS4 sebagai Lapisan Penyerap Cahaya pada Sel Surya Menggunakan Metode Elektrodeposisi
Abstrak: Thin film of Cu2ZnSnS4 (CZTS) is an alternative semiconductor used as light absorber layer on solar cell. CZTS can replace silicon that commonly used as commercial semiconductor. The advantage of using CZTS as absorber layer is due to the abundance of its chemical composer on earth, and its high value of absorption coefficient. The absorber layer was made by using electrodeposition method on ITO glass substrates. The films were deposited at room temperature using potentiostatic mode with a potential of –1.05 V for 30, 45, and 60 minutes. After that, the films were annealed at two different temperatures, 180 ºC and 500 °C, for 45 minutes in N2/H2S atmosphere. Based on X-ray diffraction analysis, the polycrystalline thin film obtained fall into kesterite crystal phase. This type of crystal was obtained when the CZTS was annealed at 500 °C in H2S/N2 atmosphere. The value of optical band gap energy for the CZTS thin film was 2.2 eV with the film thickness about 1.228–6.366 μm. The sample of CZTS with electrodeposition time of 45 minutes and annealing temperature of 500 °C showed the best result and in conformity with absorber layers criteria for solar cells.
Keyword: semiconductor, ITO glass, CZTS thin film, electrodeposition