Judul: Deteksi Pencilan pada Data Titik Panas Menggunakan Clustering Berbasis Medoids
Abstrak: Forest fire is one of disasters which has a very adverse impact. Land and forest fires in Indonesia are caused by several factors, such as prolonged drought, human negligence and irresponsible parties who deliberately set fire to achieve certain goals. Hotspot is an indicator of forest fires. The purpose of this study is to detect outliers in hotspots in 2001 until 2012. Hotspot data were obtained from the NASA FIRM. The outlier detection was performed using medoid based clustering methods, namely PAM and CLARA. The result of PAM algorithm show that outliers occur in cluster k=17 with medoid 13,14,15,16 and 17. The result of CLARA algorithm show that outliers occur in cluster k = 19 with medoid 14,15,17 and 19. PAM and CLARA algorithm detect outliers in February, March, June, July and August. Clustering results are expected to assist the authorities in determining potential areas for forest fires prevention
Keyword: Bogor Agricultural University (IPB), outlier detection, hotspot, forest fires, k-medoids, clustering

Judul: Outlier detection on hotspot data in province riau using K-Means Clustering algorithm
Abstrak: Kebakaran hutan merupakan masalah yang selalu berulang di Provinsi Riau. Salah satu solusi dari masalah ini adalah memanfaatkan data titik api hasil penginderaan jarak jauh. Tujuan penelitian ini adalah mendeteksi pencilan yang terdapat pada data titik api di Provinsi Riau dari tahun 2001 hingga 2012. Deteksi pencilan dilakukan dengan menggunakan metode clustering k-means serta digunakan pendekatan pencilan global dan kolektif. Pada fungsi kmeans digunakan nilai k sebesar 10 sehingga dihasilkan nilai sum of squared error sebesar 18 526.14. Hasil menunjukkan bahwa berdasarkan pendekatan pencilan kolektif dideteksi pencilan titik api terdapat pada cluster 5, 7, dan 10. Di samping itu diperoleh 30 pencilan titik api berdasarkan pendekatan pencilan global. Kemunculan pencilan pada data titik api banyak terjadi pada bulan Februari, Maret, Juni, dan Agustus. Frekuensi pencilan titik api tertinggi terjadi pada tahun 2005 yaitu sebanyak 1118 titik api pada 21 Juni 2005. Adapun frekuensi pencilan titik api terkecil yaitu sebanyak 295 titik api pada tahun 2005 dan rata-rata frekuensi pencilan titik api sebesar 482.22., Forest fire is considered as periodic event in several areas in Indonesia including in Riau Province. One of solutions in fire prevention is analyzing hostpot occurrences data that are produced by remote sensing technology The objective of this research is to detect outliers on hotspot data in Riau Province for the period 2001 to 2012. Outlier detection was done using the clustering k-means algorithm, and use a approach global outliers and collective outlier. The best clustering result was selected on the number of cluster 10 and the sum of squared error value is 18526.14. The results showed that based on a collective outlier approach, the outliers were obtained on cluster 5, 7 and 10. In addition, 30 outliers on hotspot data were detected based on the global outlier approach. The outliers on the hotspot data were mostly occurred in February, March, June, and August. The highest frequency of outliers occurred in 2005 reach 1118 hotspots on 21 June 2005. While the lowest frequency of outliers is 295 in 2005 and the average frequency of outliers is 482.22. Keywords: clustering, hotspot, k-means, outlier, riau
Keyword: clustering, k-means, pencilan, Riau, titik api

Judul: Extracellular Expression of thermostable Geobacillus stearothermophilus T1.2RQ Lipase for Biodiesel Production
Abstrak: The extracellular expression of enzymes in an excellent secretion host such as Bacillus subtilis is a useful strategy for making enzymes of industrial significance more affordable by lowering the cost of its downstream processing. Lipases are a category of hydrolases that catalyze the hydrolysis of triglycerides to glycerol and free fatty acids. Also, lipases catalyze the hydrolysis and transesterification of other esters as well as the synthesis of esters. They can perform very specific biotransformation reactions and are widely used in food, organic synthesis, detergents, cosmetic, and pharmaceutical industries. Geobacillus stearothermophilus T1.2RQ lipase is an industrially-desired thermostable lipolytic enzyme with an excellent hydrolytic and transesterification activity. This study aimed to express T1.2RQ lipase, in B. subtilis WB800 and ensure its secretion into the extracellular medium. Three signal peptides (AmyQ, Epr, LipA) and two promoters (Pgrac01 and Pgrac100) were used in the secretory-expression of T1.2RQ lipase, based on five constructed expression vectors constructed by restriction cloning and PCR mutagenesis. Sangers sequencing was used to verify constructs to ensure they are in the correct reading frame. Recombinants vectors, pHT43 (plasmid control), pHT43-T1.2RQ, pHT43- T1.2RQ_AmyQ, pHT43-T1.2RQ_Epr, and pHT43-T1.2RQ_LipA, were transformed by electroporation into Bacillus subtilis WB800. The electroporation was successful with the optimum condition of 2500V, 200 ohms, 25µF, and 5milliseconds. Recombinant B. subtilis pHT43 (negative control) and pHT43-T1.2RQlip + signal peptides were streaked on the lipidic agar, LA+TBN. All four recombinants, including the negative control (B. subtilis WB800-pHT43), produced clear zones on the TBN agar plate after overnight incubation (fig 2), indicating the presence of a lipolytic enzyme in all of the recombinant B. subtilis cells. pHT43-T1.2RQlip + signal peptides (AmyQ, Epr, and LipA) have clear zones with significantly higher diameters than B. subtilis WB800-pHT43 (negative control). This phenomenon suggests that the recombinant thermostable lipase T1.2RQ introduced into these cells was successfully expressed, thereby increasing the lipolytic capability of its host cells T1.2RQ lipase was expressed in 50ml terrific broth medium (TB) and the expression induced with 1mM IPTG. Lipase activity assay using p-nitrophenyl esters showed that all three signal peptides directed the secretion of T1.2RQ lipase into the extracellular medium. Signal peptide, LipA, resulted in the highest extracellular activity of 5.6 U/mL, which corresponds to a 6-fold increase over the parent B. subtilis WB800 strain. Meanwhile, signal peptides, AmyQ and Epr produced 4.2 U/mL and 3.4 U/mL activity respectively. SDS-Zymogram analysis confirmed that T1.2RQ lipase was correctly processed and secreted in its original size of 44 kDa. An attempt to further increase lipase expression level by promoter optimization showed that, contrary to expectation, promoter Pgrac100 exhibited similar expression levels as the original Pgrac01. Nevertheless, the demonstration of the successful secretion of T1.2RQ lipase in this work confirms the latter as a promising approach for the industrial production of the enzyme
Keyword: Bacillus subtilis, Expression, Extracellular, Heterologous, Lipase, Thermostable