Judul: Keberadaan H2S Pascaaerasi Hipolimnion pada Kawasan Keramba Jaring Apung (KJA) di Danau Lido, Bogor, Jawa Barat
Abstrak: Tujuan dari penelitian ini adalah mempelajari keberadaan hidrogen sulfida (H2S) pascaaerasi hipolimnion dengan lokasi penelitian di Danau Lido, Bogor, Jawa Barat. Penelitian dilakukan dari bulan Mei hingga Agustus 2011 dengan pengambilan sampel pada 5 titik yang ditentukan secara purposive sampling berdasarkan arus yang keluar dari outlet alat aerasi, yaitu 0; 1,5; 3; 4,5; dan 8 m. H2S merupakan salah satu bentuk sulfur anorganik yang bersifat racun (toksik) yang dihasikan dari aktivitas biologis bakteri pada kondisi anaerob bahan-bahan organik yang mengandung sulfur serta berasal dari hasil reduksi sulfat (SO42-) di dalam lapisan sedimen. H2S banyak ditemukan di lapisan hipolimnion, karena dalam kondisi oksigen yang sangat rendah akan terjadi akumulasi H2S akibat adanya peningkatan pertumbuhan bakteri anaerob. Aerasi hipolimnion yang dilakukan diharapkan dapat meningkatkan konsentrasi oksigen sehingga proses perombakan bahan organik yang mengandung sulfur tidak menghasilkan H2S yang merugikan bagi kehidupan biota akuatik di dalam danau. Hasil penelitian ini menunjukkan bahwa aerasi yang dilakukan selama 10 jam mampu menurunkan konsentrasi H2S di lapisan hipolimnion Danau Lido, rata-rata sebesar 51,85%. Penurunan terbesar terjadi pada jarak 3 m dari titik outlet aerasi (60%). Setelah aerasi dihentikan konsentrasi hidrogen sulfida mengalami peningkatan, akan tetapi dengan konsentrasi lebih kecil dibandingkan sebelum aerasi dilakukan.
Keyword: aerasi hipolimnion, hidrogen sulfida

Judul: Keberdaan Fosfat Pascaaerasi Hipolimnion pada Lokasi Keramba Jaring Apung di Danau Lido, Bogor, Jawa Barat
Abstrak: The purpose of this research is to study about phosphate presence after hypolimnetic aeration in Lido Lake, Bogor, West Java. The research is carried out from May to July 2011 with 5 sampling spot which is decided by purposive sampling based on the aeration equipment outflows, consist of 0 m;1,5 m; 3 m; 4,5 m; and 8 m. Orthophosphate is one of dissolved inorganic phosphate form that can be used by algae and aquatic plant directly. The presence of orthophosphate is affected by dissolved oxygen concentration in water. Orthophospate mostly found in hypolimnetic layer, this is happened because orthophosphate can form a bond and precipitation with Fe, Ca, or Al ion in the oxic condition, then fall to the bottom of water. In the other side, in anoxic condition, the bond between orthophospate and Fe, Ca, or Al ion will be released. This research aim to observe the presence of phosphate after hypolimnetic aeration. This aeration is expected to increase the ability of ions to make a bond and do precipitation with orthophosphate. The research showed that aeration which is done for 10 hours can decrease the orthophosphate concentration in hypolimnetic layer of Lido Lake for 21,05- 97,56%. The most slope is occurred in 3 m distance from the outlet of aeration (97.56%). After the aeration, the decrease of orthophosphate concentration still can be maintained for 5 hours. The concentration of orthophosphate begin to increase after 10 hours from the end of aeration.
Keyword: 

Judul: Application of Mel Frequency Cepstrum Coefficients (MFCC) as Feature Extraction on Phoneme Recognition with Probabilistic Neural Network (PNN) as Classifier
Abstrak: Voice recognition (speech recognition) is one field of study in voice processing. This technology can convert voice signals into a form of written information (text). With this technology, people can interact with a computer. MFCC feature extraction computes the cepstral coefficients by considering the human hearing. This research is a phoneme recognition using feature extraction MFCC and PNN as feature matching model. This study compares the coefficient, overlap, and the test data without noise and with noise. MFCC is used with 13, 20, 26 coefficients and 0%, 25%, 50% overlap. Noise is added by 30 dB, 20 dB and 10 dB. From the comparison of the three overlaps, produced the best accuracy at 50% overlap with an accuracy of 94,71%. From comparing the three coefficients, better accuracy resulting in coefficients of 20 and 26 with an accuracy of 97,12% at 50% overlap. After comparing between the coefficients of 20 and 26 with overlap of 25% then the coefficient 26 is obtained that better accuracy of 94,23%. This shows that in this study the coefficient 26 is the best. In this research, there are three noise variables. The variables are 10 dB, 20 dB, and 30 dB. The best accuracy reached when the noise variable is 30 dB rather than 10 dB or 20 dB because the accuracy has the closest accuracy compared by the accuracy when noise was not added into the data. When the noise variable is 30 dB, the percentage of accuracy is 85,3%.
Keyword: