Judul: Pengenalan Kata Berbahasa Indonesia dengan Hidden  Markov Model (HMM) menggunakan Algoritme Baum-  Welch
Abstrak: Pengenalan suara atau Speech Recognition adalah proses konversi sebuah sinyal akustik, yang berasal dari mikropon atau telepon, menjadi satu atau sekumpulan kata. Sinyal suara sendiri merupakan gelombang yang tercipta dari tekanan udara yang berasal dari paru-paru yang berjalan melewati lintasan suara menuju mulut dan rongga hidung, sehingga memiliki frekuensi yang berbeda. Agar sistem komputer dapat mengenali sebuah kata, maka dibutuhkan representasi yang tepat terhadap sinyal-sinyal yang masuk berikut perubahan frekuensinya dalam rentang waktu tertentu. Penelitian ini menggunakan Algoritme Baum-Welch dalam melatih HMM sebagai model kata. Adapun tujuan penelitian ini ialah menerapkan HMM menggunakan algoritme Baumwelch untuk mengenali sebuah kata. Kata yang digunakan terbatas pada 40 buah kata berbahasa Indonesia yang dibedakan ke dalam 2 macam jumlah suku kata, yaitu : 2 suku kata dan 3 suku kata. Pembicara pada penelitian ini juga dibatasi pada 2 orang pembicara perempuan dan 2 orang pembicara laki-laki yang telah terlatih sebelumnya.
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Judul: Pengembangan Hidden Markov Models untuk fonem berbahasa Indonesia pada sistem konversi suara ke teks
Abstrak: Speech to text transcription system is a system used to convert a voice signal from a microphone or a telephone into a single or a set of words. Research on speech to text transcription systems has been widely applied. But these systems tend to be developed based on words, hence they are inefficient when developed for a large vocabulary. This study uses Baum Welch algorithm for HMM training, Forward algorithm for HMM testing, and Mel-Frequency cepstral coefficient (MFCC) to extract voice features. Data used in this study consist of 5 words in Indonesian language. Phonemes are generated from the segmentation process, and then trained with Baum Welch algorithm to generate the model. This study produced 10 models. The best accuracy obtained is 82% generated by testing the HMM with 2 States and 5 epochs
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Judul: Hybrid solar cells of ZnO nanoparticles/chlorophyll was modified metal ions (Zn2+ and Cu2+ )
Abstrak: Zinc Oxide (ZnO) is a n-type semiconductor with a wide the energy band (Band Gap) is 3.37 eV at room temperature and 3.34 eV at low temperature with a large exiton binding energy is 60 meV. ZnO has been synthesized by hydrothermal method, resulting in a decrease in particle size over the duration of the hydrothermal changes. Crystallographic structure of ZnO were characterized using XRD, has shown the characteristic pattern of a hexagonal wurtzite structure, the crystallite size increases to changes in particle size. Changes in particle size has also led to a change in the absorption peak of ZnO as has been demonstrated posted under test using the optical properties of UV-Vis spectrophotometer. Changes of this uptake has also led to changes in the energy band gap, which increases its band gap energy of the particle size. In electronic applications, especially in solar cells. Chlorophyll is considered less effective, because of their very nature are easily degraded as a result of several reactions which are acid, lighting and temperature. The results of the stability test using a halogen lamp 34 W/m2 for 5 hours, that the substitution of chlorophyll with metal ions Zn2+ and Cu2+ has been shown to form more stable than natural chlorophyll. The characterization of the optical properties, the combination of ZnO / chlorophyll in the form of hybrid films has led to a shift in the absorption region of ZnO becomes more widely from the UV to Visible. ZnO/chlorophyll has absorption range of 350-515 nm, ZnO / Zn-feofitin 332-401 nm and 332-632 nm for Cu-feofitin. The combination of ZnO/chlorophyll and CuSCN as a solid electrolite in hybrid solar cell, a modified chlorophyll with metal ions Zn2+ and Cu2+ has been shown to form a more stable I-V curve. It is characterized by its fill factor value greater than natural chlorophyll. Nevertheless, solar cells with natural chlorophyll has been able to produce higher efficiency values of chlorophyll were substituted.
Keyword: Hydrothermal, ZnO/Chlorophyll modified, Hybrid Solar Cell