Judul: Synthesis of Violin String Picks and Swipe With Variation of Pick Points Using Fourier Transform
Abstrak: Penelitian ini bertujuan menganalisis sinyal periodik yang dihasilkan petikan dan gesekan senar biola. Terdapat dua tahapan pada penelitian ini yakni tahap analisis dan tahap sintesis bunyi setiap senar biola. Senar biola dipetik pada beberapa posisi dengan simpangan sebesar 1 mm hingga 5 mm. Data dianalisis dengan software MATLAB untuk mendapatkan koefisien redaman, grafik simpangan sebagai fungsi waktu, dan spektrum frekuensi dari bunyi yang dihasilkan. Hasil penelitian menunjukkan frekuensi bunyi petikan senar biola berbanding lurus dengan koefisien redamannya dan terdapat pergeseran frekuensi lebih rendah pada kenaikan amplitudo tarikan. Setelah itu, data disusun untuk disintesis menggunakan MATLAB agar menghasilkan simpangan sebagai fungsi waktu dan bunyi dari petikan dan gesekan senar biola. Pengolahan data lanjutan menggunakan software Microsoft Excel untuk menampilkan perbandingan koefisien redaman dan hasil sintesis., This study aims to analyze the periodic signal generated by the plucking and swiping violin strings. There are two stages in this research, namely the analysis stage and the sound synthesis stage for each violin string. The violin strings are plucked in several positions with a deviation of 1 mm to 5 mm. The data were analyzed using MATLAB software to obtain the attenuation coefficient, the deviation graph as a function of time, and the frequency spectrum of the sound generated. The results showed that the frequency of the plucked violin strings was directly proportional to the damping coefficient and there was a lower frequency shift as the amplitude of the pull increased. After that, the data was compiled to be synthesized using MATLAB in order to produce deviations as a function of time and sound from the plucking and friction of the violin strings. Advanced data processing using Microsoft Excel software to display the comparison of attenuation coefficients and synthesis results.
Keyword: detache, pizzicato, FFT, damping coefficient, violin strings

Judul: Analisis dan Sintesis Bunyi Petikan Senar Ukulele dengan Variasi Titik Petik Menggunakan Transformasi Fourier
Abstrak: Penelitian ini bertujuan untuk menganalisis bunyi yang dihasilkan senar ukulele dengan variasi titik petik menggunakan Transformasi Fourier. Membuat model matematis dalam fungsi frekuensi sebelum ditransformasikan ke dalam fungsi waktu untuk menghasilkan bunyi sintesis. Senar ukulele dipetik pada beberapa posisi dengan tegangan 4,0 N. Bunyi senar ukulele direkam dengan sensor bunyi yang terhubung dengan software PASCO Capstone. Data dianalisis menggunkan software Octave. Pulsa lancip ditemukan di daerah frekuensi nada dasar dan nada atas. Amplitudo relatif nada-nada atas bervariasi tergantung pada posisi titik-titik petik, yaitu semakin dekat ke ujung senar, semakin besar amplitudo relatifnya. Untuk titk petik di 0,33 L, lebar pulsa nada dasar akan bertambah seiring dengan bertambahnya frekuensi, yaitu 3,36 Hz, 11,44 Hz, 27,93 Hz, dan 34,79 Hz untuk frekuensi 258 Hz, 313 Hz, 383 Hz, dan 434 Hz. Hasil ini menunjukkan bahwa suara ukulele yang dibuat oleh model matematika sangat mirip dengan aslinya., This research aims to analyze the sound produced by ukulele strings with variation of the pluck points using the Fourier Transformation. A mathematical model was built in the frequency domain before being transformed into the time domain for creating a synthetic sound. Ukulele strings were plucked at several positions with a tension of 4.0 N. The sound of the ukulele strings is recorded with a sound sensor connected to the PASCO Capstone software. Data were analyzed using Octave software. The sharp pulses were found in the frequency area of the basic and upper notes. The relative amplitude of the overtones varies depending on the position of the pluck points, i.e. the closer to the end of the string, the bigger the relative amplitude is. For the pick points at L/3, the pulse width of the fundamental tone will increase as the frequency increases, namely 3.36 Hz, 11.44 Hz, 27.93 Hz, and 34.79 Hz for the frequencies of 258 Hz, 313 Hz, 383 Hz, and 434 Hz. The results have shown that the ukulele’s sound created by the mathematical model are very similar to the original one.
Keyword: fourier transform, pulse width, ukulele strings

Judul: Codiaeum Malesia
Abstrak: The Malesian genus Codiaeum has been revised based on the morphological character using available herbarium collections in Herbarium Bogor iense and loan specimens from Rijksherbarium Leiden. The study is based on the observation of 350 specimens. Eleven species have been recognized, namely Codiaeum variegatum, C. luzonicum, C. palawanense, C. trichocalyx, C. megalanthum, C. cilliatum, C. affine, C. tenerifolium dan C. hirsutum, C. macgregorii, C. ludovicianum. number of species is found in the Philippines The highest (8 species), Two species (C. tenerifolium and C. ludovicianum) endemic in Lousiade Archipelago of the New Guinea and C. affine endemic in Banguey Island. C. variegatum is widespread by nature or in cultivation almost in all of Malesian region. C. cillia tum is a species in the earliest level among the other species according to 20 selected characters.
Keyword: Codiaeum, Malesia