Judul: Enkripsi Suara pada Raspberry Pi Menggunakan Algoritma AES Dengan Mode OFB
Abstrak: Privasi adalah salah satu aspek yang harus diperhatikan saat ini dikarenakan munculnya isu-isu spionase dan penyadapan yang dilakukan oleh pihak lain terhadap pengguna telekomunikasi selular. Penelitian ini akan memberikan proof of concept tentang pengamanan komunikasi data khususnya data suara dalam telekomunikasi seluler menggunakan sebuah algoritma enkripsi AES dengan mode output feedback (OFB). Algoritma ini akan diimplementasikan ke dalam Raspberry Pi sebagai salah satu media yang memiliki kemiripan dengan smartphone dari segi arsitektur sistem. Hasil penelitian ini belum dapatditerapkan pada smartphone dengan sistem operasi berbasis Android sebagai sebuah program aplikasi. Kendala yang dihadapi adalah bahwa program aplikasi enkripsi suara hasil penelitian ini dikembangkan menggunakan bahasa pemrograman yang belum didukung sepenuhnya oleh arsitektur sistem smartphone.
Keyword: AES, output feedback, proof of concept, Raspberry Pi

Judul: Analisis hasil enkripsi file wave menggunakan sandi algoritme berkelamp-massey
Abstrak: Secured voice data transfer is an important thing to be noticed, especially when dealing with confidential data. A technique used in assuring the transfer is encrypting the data. This technique applied symmetric key stream cipher Left Feedback Shift Register (LFSR) generator. The key developed by LFSR generator also contains high level of safety because it has semirandom byte stream key with large period. However, the influence of voice encryption using LFSR symmetric key to the wave format files is not widely known. Besides, this technique's safety level must be examined further as a consideration for larger use. This research tends to test the impact of encryption using LFSR symmetric key stream cipher on voice recorded as wave file format, and its safety level. Wave files employed on this research recorded using Sound Recorder application on Windows Operation System. These files have various fast and slow rythm. The result of this research was the change on the voice after being encrypted, with different intensity of noise, that will affect the clarity of voice's message contents. Some voices have message that could be identified well, and others couldnn't be identified at all. The result of the analysis showed that the factors influence the encryption were the rythm of the voice, and the type of polynomial applied (primitive / non primitive; polynomial degree, and linear complexity measured by Berlekamp- Massey Algorithm). Furthermore, the encrypted voices could be recovered to their genuine source while the key to decrypt is similar with the encryption key.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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