Judul: Pengaruh Penggunaan Zeolit Bayah sebagai Matriks Imobilisasi pada Aktivitas Antioksidan Superoksida Dismutase Deinococcus radiodurans
Abstrak: Immobilization of superoxide dismutase (SOD) from extract of D. radiodurans has been studied over past years. D. radiodurans is a bacteria that produces enzyme Mn-SOD. The optimum condition of SOD antioxidant activity of D. Radiodurans extract is at 30 °C, pH 9, 137.5 mg of zeolite Bayah and 1500 g/L extract of D. radiodurans concentrate. The determination of kinetics reaction is based on the method of Lineweaver-Burk and Eadie-Hoofstee, which resulted KM app SOD value of immobilized extract D. radiodurans on zeolite is higher than without immobilized extract D. radiodurans. Furthermore, the value of IM app of immobilized extract D. radiodurans is really massive, 7.0373 μA. The electrode stability of immobilized extract D. radiodurans still 57.70% after 8 hours, compared to without immobilized extract D. radiodurans that dropped to 45.04% after 2 hours.
Keyword: zeolite, superoxide dismutase, Deinococcus radiodurans, antioxidant

Judul: Aktivitas dan Stabilitas Superoksida Dismutase dari Ekstrak Deinococcus radiodurans yang Diimobilisasi pada Zeolit Alam sebagai Biosensor Antioksidan
Abstrak: Immobilization of superoxide dismutase (SOD) from extract of Deinococcus radiodurans have been studied. D. radiodurans is a bacteria having an enzyme Mn-SOD. The optimum condition of SOD antioxidant activity of the extract was at 31 °C, pH 9, and 157 mg zeolite. Determination of Michaelis-Menten constant was based on Lineweaver- Burk, Eadie-Hoofstee, and Hanes methods. The KMapp of SOD of the extract immobilized on zeolite was lower than that of without immobillization. Electrode stability was relatively stable up to 22 hours. Antioxidant activity of using zeolite as the matrix was higher than that of the unimmobilization. The antioxidant activity on electrode with zeolite at 22nd hour was 64.0 %, and the stability of electrodes without zeolite at the same time was only 49.3 %. The SOD of D. radiodurans is potential as a biosensor for antioxidants because of the high antioxidant activity despite of the low stability.
Keyword: superoxide dismutase, natural zeolites, Deinococcus radiodurans, antioxidant biosensor

Judul: Pemodelan chord pada piano menggunakan metode fuzzy learning vector quantization
Abstrak: Seorang pemain piano pemula maupun autodidak umumnya belum melalui tahap latihan yang baik sehingga kemampuan untuk mengenali chord yang dimiliki masih kurang. Oleh karena itu, suatu sistem yang dapat mengenali chord untuk membantu proses pemahaman chord yang dimainkan dibutuhkan. Penelitian ini memodelkan chord yang terdiri atas 3 nada (triad) ke dalam beberapa kelas. Data yang digunakan dalam penelitian ini adalah 24 chord mayor dan minor. Data training dan data testing divariasikan dalam 4 model menggunakan 5-fold crossvalidation. Ekstraksi ciri akan dilakukan dengan metode Mel Frequency Cepstrum Coefficients, dan klasifikasi akan dilakukan dengan metode Fuzzy Learning Vector Quantization (FLVQ). Pemodelan FLVQ dilakukan dengan melakukan variasi pada learning rate serta koefisien fuzzyness. Penelitian ini telah berhasil membentuk model FLVQ dengan akurasi rata-rata 79.38% serta akurasi maksimum 100%. Akurasi maksimum dicapai dengan nilai learning rate α sebesar 0.05 dan koefisien fuzzyness β sebesar 0.05 menggunakan epoch sebanyak 20 pada FLVQ model 2.
Keyword: chord, FLVQ, MFCCs, modeling, note.