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: Classification of imbalanced data using weighted k-nearest neighbor in data bank credit card debtors
Abstrak: Manajemen risiko kredit bertujuan untuk meminimalkan potensi kerugian dari kredit macet. Analisis data debitur bermasalah yang sudah ada dapat menjadi model dalam kualifikasi pemberian kredit selanjutnya. Data debitur bank termasuk kasus data tidak seimbang. Proses klasifikasi menjadi tidak optimal karena kelas dengan jumlah data lebih banyak memberikan pengaruh yang sangat besar dalam hasil klasifikasi. Penelitian ini bertujuan untuk mengembangkan model klasifikasi data debitur kartu kredit menggunakan algoritme weighted k-nearest neighbor dan metode sampling yang bertujuan meningkatkan kualitas klasifikasi pada data tidak seimbang. Metode sampling yang digunakan yaitu oversampling dan undersampling. Metode oversampling acak menghasilkan nilai f-measure terbaik sebesar 86.51%. Metode oversampling duplikasi menghasilkan nilai recall terbaik sebesar 100%., Credit risk management aims to minimize potential losses of non-performing loans. The classification results of existing data debtors can be referred for credit qualifications. The debtors data, most likely, are imbalanced due to the good debtors dominated the bad one. Classification process could not be optimum because of the class with more data had tremendous influence in the classification result. This research aims to develop a data classification model based on credit card debtors using weighted k-nearest neighbor and sampling method which aimed to improve the quality of classification on the imbalanced data. The sampling methods used are the oversampling and undersampling. The random oversampling method obtains the best performance with F-measure of 86.51%. Moreover, the duplication oversampling can obtain 100% recall. Keywords: imbalanced data, oversampling, undersampling, weighted k-nearest neighbor
Keyword: data tidak seimbang, oversampling, undersampling, weighted k-nearest neigbor

Judul: Pemurnian dan karakterisasi protein inhibitor RNA helikase virus hepatitis C
Abstrak: Hepatitis C virus (HCV) infection is the second most common chronic viral infection in the world with global prevalence. This infection is contribution to chronic hepatitis and liver cirrhosis, often leading to hepatocellular carcinoma. There is no effective drug and vaccine available against HCV. The current standard treatment, a combination of pegylated interferon-α with ribavirin, is limited by its suboptimal response rate in a significant patient population, side effects, and affordability. Therefore, development of effective drug is needed. One approach to find out the candidate of antiviral drug is to discover the inhibitor of enzyme that essential for virus replication, such as RNA helicase. Streptomyces chartreusis 5-095 produce the inhibitor of HCV RNA helicase. The aim of this study was to purify the protein inhibitor which has inhibition activity against ATPase activity of RNA helicase HCV from S. chartreusis 5-095. The supernatant of culture S. chartreusis 5-095 exhibited high inhibiton activity against ATPase activity of RNA helicase HCV (approximately 72%) at 10 days of incubation. The extracellular protein inhibitor was partially purified by procedures of precipitation with ammonium sulfate to 65% saturation and gel filtration (Sephadex G50) using methanol water solution (4:6) as an eluen. The purity of protein inhibitor was monitored by SDS PAGE. The protein inhibitor showed a relative molecular mass were estimated to be 14 kDa and increased the purity 23,08 fold than those of the crude protein. The specific activity and IC50 after purification were 13,1338 U/mg and 0,0767 mg/mL, respectively. The activity of purified protein inhibitor showed its stability over pH range from 5-8 and optimum at pH 7,4. The inhibition activity showed its stability up to 70% at temperature 100 oC. The purified protein inhibitor relatively stable its activity at storage in the range of -20 oC to room temperature for 35 days.
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