Judul: Pembangunan Metode Codebook untuk Identifikasi Chord Gitar dengan Teknik Ekstraksi Ciri MFCC
Abstrak: Various types of chords can be produced by a guitar instrument. However, it is difficult to recognize a guitar chord manually. This research develops a system to recognize a chord on the guitar using codebook, MFCC, and K-means clustering. The codebook is used as the pattern recognition method for identification of guitar sound, while MFCC is used as a method of feature extraction. The parameters used in the process of MFCC are the number of cepstral coefficients, overlap, and the time frame, while the parameter used in the process of K-means clustering is the number of cluster. This research used 1440 guitar sound data that are divided into 72 class, so that each class has 20 guitar sound data. The results showed that the maximum accuracy obtained is 99.72% when the number of cepstral coefficients are 26, overlap value is 0.4, time frame is 30 ms, and the number of cluster is 5.
Keyword: Chord, Codebook, Guitar, K-Means, MFCC

Judul: Pengenalan Chord pada Alat Musik Gitar Menggunakan Codebook dengan Teknik Ekstraksi Ciri MFCC
Abstrak: Human auditory system is capable of extracting rich and meaningful data from complex audio signal. To recognize chord sequences that played in some kind of music is not an easy task. People need big effort to train their sense of hearing so they can recognize that kind sound of chords. This condition is also valid in a computer system. Finding the key and labeling the chords automatically from music are great use for those who want to do harmonic analysis of music. Hence automatic chord recognition has been a topic of interest in the context of Music Information Retrieval (MIR) for several years, and attempts have been made in implementing such systems using well understood signal processing and pattern recognition techniques. This research is about to recognize the sound of chord that played and recorded by guitar instrument. There are 24 major-minor chords that used in this research. MFCC is used as feature extraction and the number of coefficient cepstral that used are 13 and 26. Each chord signal that has been extracted then clustered using K-means algorithm with 8, 12, 16, 20, 24, 28, 32 k numbers to create codebook that use as a model of each chord. For the recognition process, there are two methods that used in this research, unstructured recognition and structured recognition. For the result, this research produces two kinds model of codebook that are codebook with 13 coefficients and codebook with 26 coefficients. Both types of codebook show a good result with accuracy level above 88%. The best result yielded from usage of 26 coefficient cepstral with structured recognition. It’s accuracy level reach 97%. Hence the usage of 26 coefficient cepstral is better than the usage of 13 coefficient cepstral with difference of accuration level is about 7%. This research also shows the affectation of the numbers k-means that used. An increasing accuration level shown by increasing the amount of k-cluster.
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Judul: Peranan Infeksi Transplasental Virus Bovine Viral Diarrhea Pada Sapi
Abstrak: Tulisan ini bertujuan untuk mengetahui peranan infeksi transplasental virus bovine viral diarrhea pada sapi ditinjau dari segi patogenesa dan imunitasnya. Bovine Viral Diarrhea (BVD) merupakan penyakit pada saluran pencernaan dan pernafasan yang ditandai dengan gejala demam, salivasi, keluarnya sekresi nasal dan kadang-kadang diikuti diare. Penyakit ini disebabkan oleh Pestivirus. Penularan penyakit BVD pada sapi dapat terjadi melalui kontak secara langsung maupun tak langsung dengan sekresi dan ekskresi yang dihasilkan sapi yang terinfeksi virus BVD. Domba, rusa dan babi dapat pula menularkan penyakit ini pada sapi. Pada sapi tidak bunting, infeksi ini menyebabkan penyakit pada saluran pencernaan dan pernafasan yang bersifat ringan. Sapi yang terinfeksi virus BVD akan segera membentuk zat kebal dalam tubuhnya. Kekebalan yang telah terbentuk dapat melindungi sapi tersebut terhadap infeksi virus BVD selanjutnya. Sedangkan pada sapi bunting, infeksi ini selain menyebabkan penyakit pada saluran pencernaan dan pernafasan juga dapat mempengaruhi perkembangan fetus melalui infeksi secara transplasental.
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