Judul: Algoritma uji komposit berdasarkan teorema kongruensi fermat dan teorema strong pseudoprime
Abstrak: Dalam menentukan apakah suatu bilangan bulat positif ganjil m merupakan bilangan komposit atau bukan, diperlukan suatu uji. Uji tersebut dinamakan uji komposit. Uji Komposit I adalah uji yang didasarkan pada Teorema Kongruensi Fermat. Input dari uji ini adalah bilangan bulat m dan a sebagai basis. Jika uji berhasil maka m dapat dikatakan sebagai bilangan komposit. Jika tidak, maka m dikatakan bilangan diduga prima berbasis a, dimana a adalah anggota dari himpunan bilangan-bilangan bulat modulo m yang relatif prima dengan m. Uji Komposit II adalah uji yang didasarkan pada Teorema Strong Pseudoprime. Input dari uji ini adalah bilangan yang tidak dapat ditentukan kekompositannya menggunakan Uji Komposit II, yaitu bilangan diduga prima berbasis a. Jika uji berhasil maka m merupakan bilangan komposit dan disebut bilangan prima semu berbasis a. Jika tidak, maka m dikatakan bilangan diduga kuat prima berbasis a.
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Judul: Pembangkitan Bilangan Prima dengan Metode Saringan Eratosthenes
Abstrak: Cryptograph is required in securing information or data transmission. In cryptograph, prime numbers are required in high level message security. These prime numbers are acquired by generation method. There are many considerable methods which can be implemented to find prime numbers, one of them is the sieve of Eratosthenes method. There is another method to generate prime numbers, which is called Miller-Rabin prime test algorithm. The aims of this paper are to study and implement the sieve of Eratosthenes method and Miller-Rabin prime test algorithm, and then to compare these algorithms. The sieve of Eratosthenes method is applied to find all prime numbers up to a specified integer n. The filtering is acquired by determining all prime numbers which are smaller or equal to L J;, J and cancelling all integers which are multiple of these prime numbers. In Miller-Rabin prime test algorithm all prime numbers in one interval is determined by applying a certain test to each number within this interval. According to the implementation results, time requirement to execute the sieve Eratosthenes algorithm is shorter than the Miller-Rabin prime test algorithm. The sieve Eratosthenes algorithm needs o( n(lgn)2Ig Ign) bit operations, while generation of prime numbers using Miller-Rabin prime test algorithm needs O({10gnf) bit operations. Nevertheless, the memory requirement of sieve Eratosthenes is higher than Miller-Rabin prime test algorithm. It is because the sieve Eratosthenes algorithm consumes n array and memory consumption of the Miller-Rabin prime test algorithm is negligible (constant).
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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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