Judul: Clustering Jamur Asterinaceae Menggunakan Metode K-Means
Abstrak: Fungi are one of the many cultivated crops by farmers in upland areas. Fungi are beings who are heterotrophic eukaryotes, which absorbs organic matter from the environment so that his life is parasitic and saprophyte. Diversity of these fungi cause difficulty to distinguish between one type and another. Before identifying fungi taxa Asterinaceae Australia, a grouping or clustering method is required to recognize the fungi by their characteristics. In grouping these fungi, characteristics possessed are first converted into binary form. K-Means clustering method is then utilized. There are three main stages for the clustering purpose, namely normalization, K-Means method, and Davies Bouldin Index calculation. The results show that the best clustering is obtained with 10 clusters.
Keyword: K-Means., fungi Asterinaceae, Davies Bouldin Index

Judul: Grouping of Agaric Fungus Stature Based on Landmark Geometric Morphometric Method
Abstrak: Jamur makroskopis merupakan organisme dengan keanekaragaman yang tinggi dengan sifat saprob, parasit atau fakultatif dengan banyak manfaat. Metode pengklasifikasian jamur agarik biasanya menggunakan karakter morfologi seperti bentuk cap, bentuk stipe, karakter lamella, annulus, dan volva. Pengklasifikasian jamur dapat dilakukan dengan menggunakan metode morfometrik dengan menggunakan koordinat potongan melintang tubuh buah yang dibuat perawakannya. Tujuan dari penelitian ini adalah mengelompokkan perawakan jamur agarik berdasarkan perbedaan koordinat dengan menggunakan metode morfometrik geometrik landmark. Foto sayatan membujur jamur agarik diperoleh dari lapang (18 sampel) dan literatur (33 sampel). Perawakan jamur dari foto tersebut kemudian dibuat dengan menggunakan Software MediBang Paint versi 19.5 yang dilanjutkan dengan penempatan landmark anatomi. Pengelompokan perawakan jamur ditampilkan dengan metode PCA dalam scatter plot dengan menggunakan bentuk tidak seragam (non-affine) . Hasil menunjukkan bahwa seluruh sampel dikelompokkan menjadi 4 kelompok PCA. Hanya Agaricus xanthodermes dan Agaricus silvicola (PCA 1); Lepista nuda dan Calocybe gambosa (PCA 1); Agaricus campestris dan Agaricus arvensis (PCA 3) didukung pengelompokannya berdasarkan filogenetik molekuler dari beberapa literatur. Untuk menguatkan pengelompokan sampel lainnya dalam hasil analisis PCA tersebut maka diperlukan data molekuler yang sangat banyak.
Keyword: Jamur agarik, landmark, morfometrik, perawakan

Judul: Sintesis BaTiO3 dari Campuran Ba(OH)2 dan TiO2 dengan Tambahan PbO
Abstrak: Piezoelectric material can generate electric field in response to applied mechanical stress. Conversely, they can stretch and contract in response to an electric field. This material can be used for many applications such as transducer, microphone, ultrasound, and pressure gauge. Barium titanate is a ferroelectric material with piezoelectric properties that can be synthesized easily. The aim of this study is to synthesis barium titanate from mixture of Ba(OH)2 and TiO2, also observe its optimum temperature and the effect of PbO addition. The method of synthesis was solid-state reaction and sol-gel method, then the products were characterized with x-ray diffraction (XRD). Based on XRD analysis, the optimum temperature for both methods was 800°C. Addition of PbO to BaTiO3 in the solid-state reaction formed a compound with formula of Ba1-xPbxTiO3. The addition has changed diffraction pattern peak at 2θ and strengthened its tetragonal structure. The best result was obtained at x of 0.5 which will form a compound of Ba0.5Pb0.5TiO3.
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