Judul: Penerapan Algoritme Prefixspan dan Clospan untuk Mencari Pola Sekuensial pada Data Peminjaman Buku di Perpustakaan IPB
Abstrak: Library is an important facility in university. From the library data we can obtain various information, such as patterns of borrowing books by library users. This study aims to determine the sequential patterns of IPB’s library book loan data using two algorithms namely Clospan and Prefixspan. This study used the dataset with the size ranging from 50 to 4.140 and minimum support ranging from 5% to 15%. The experimental results show that the larger dataset and the minimum support used, Clospan algorithm has better performance than Prefixspan. In addition, the results of two sequential pattern algorithms which shows the relationships between the book code 027 (general libraries) with 820 (literature) books, 631 (farm management,agronomy, andhorticulture) books with book code 636 (animal husbandry and breeding in general), and 631 (farm management,agronomy, andhorticulture) to 658 (business management, administration, and commercial organization).
Keyword: Clospan, Prefixspan, library circulation data, sequential pattern

Judul: Penentuan pola sekuensial pada data transaksi perpustakaan IPB menggunakan algoritma graph search techniques
Abstrak: Data transaksi di Perpustakaan IPB terutama peminjaman buku dicatat setiap hari sehingga menghasilkan kumpulan data transaksi peminjaman buku dalam ukuran besar. Untuk mengetahui pola perilaku peminjaman buku oleh seluruh anggota perpustakaan khususnya mahasiswa Strata 1 (S1) tahun masuk 2003 digunakan salah satu metode dalam data mining yaitu sequential pattern mining dengan algoritma Graph Search Techniques (GST) sebagai pembentuk large sequence. Algortima GST dapat menemukan urutan large k-sequence (k ≥ 3) tanpa mengetahui langsung large (k-1) sequence. Pola sekuensial yang merupakan large sequence maksimal dicari dari seluruh large sequence yang terbentuk. Pola sekuensial yang diperoleh kemudian direpresentasikan agar mudah dipahami dan diinterpretasikan. Informasi yang diperoleh diharapkan dapat berguna bagi pengelola perpustakaan dalam peningkatan mutu layanan di Perpustakaan IPB.
Keyword: 

Judul: Pengaruh Konsentrasi Katalis Methyl Ester Sulfonic Acid Terhadap Sifat Fisikokimia Gliserol Ester Oleat yang Dihasilkan
Abstrak: Glycerol is a by-product from palm olein biodiesel industry which could be value-added to obtain various products. One of the alternatives is to modify glycerol become glycerol ester oleat. Before processing, glycerol was first refined using 5% (v/v) phosphoric acid 85%. The refinery showed that glycerol content was increased from 49% to 80%. Glycerol was then esterified with oleic acid and catalyst methyl ester sulfonic acid (MESA) to obtain glycerol ester. Esterification was conducted at 240°C and nitrogen atmosphere using 200 rpm of mixing for 90 minutes. The best catalyst concentration used in esterification process is at 0,5% and resulting glycerol ester oleat with acid number 48,07 mg KOH/g sample, density of 0,9124 g/cm3, viscosity 68,32 cP (25°C), kinematic viscosity 36 cSt (40°C), flash point 230°C and pour point -15°C.
Keyword: glycerol ester, glycerol