http://blogs.najah.edu/author/allam-mousa An-Najah Blogs :: Allam Mousa en-us Sat, 27 Jul 2024 19:07:29 IDT Sat, 27 Jul 2024 19:07:29 IDT [email protected] [email protected] http://blogs.najah.edu/staff/allam-mousa/article/ldquoVoice-Conversion-Using-Pitch-Shifting-Algorithmby-Time-Stretching-with-PSOLA-and-Re-SamplingrdquoPublished ArticlesVoice Conversion Using Pitch Shifting Algorithmby Time Stretching with PSOLA and Re-Samplinghttp://blogs.najah.edu/staff/allam-mousa/article/ldquoChannel-Estimation-in-OFDM-System-over-Rician-Fading-Channel-Based-on-Comb-Type-Pilots-ArrangementrdquoPublished ArticlesChannel Estimation in OFDM System over Rician Fading Channel Based on Comb-Type Pilots Arrangementhttp://blogs.najah.edu/staff/allam-mousa/article/ldquoSecurity-and-Performance-of-ElGamal-Encryption-ParametersrdquoPublished ArticlesSecurity and Performance of ElGamal Encryption Parametershttp://blogs.najah.edu/staff/allam-mousa/article/Kalman-Filter-Channel-Estimation-Based-On-Comb-Type-Pilots-for-OFDMPublished Articles Kalman-filter method have been used for the estimation of time-frequency-selective fading channels in OFDM systems the estimation is based on Comb- type pilot frequencies arrangement the channel coefficients that belong to the pilot subcarriers are estimated Then these estimates are interpolated using different types of interpolations like; Low pass interpolation Spline cubic interpolation or Linear interpolation The performances of all schemes have been compared by finding Bit Error Rate where BPSK modulation scheme was used http://blogs.najah.edu/staff/allam-mousa/article/Evaluation-of-the-RC4-Algorithm-for-Data-EncryptionPublished ArticlesAnalysis of the effect of different parameters of the RC4 encryption algorithm where examined Some experimental work was performed to illustrate the performance of this algorithm based on changing some of these parameters The execution time as a function of the encryption key length and the file size was examined; this has been stated as complexity and security Various data types were analyzed and the role of the data type was also emphasized The results have been analyzed and interpreted as mathematical equations showing the relationship between the examined data and hence can be used to predict any future performance of the algorithm under different conditions The order of the polynomial to approximate the execution time was justified IJCSA 32: 44-56 2006http://blogs.najah.edu/staff/allam-mousa/article/Sensitivity-of-Changing-the-RSA-Parameters-on-the-Complexity-and-Performance-of-the-AlgorithmPublished ArticlesThe RSA algorithm has some important parameters affecting its level of security It is shown here that increasing the modules length plays an important role in increasing the complexity of decomposing it into its factors This will increase the length of the public key and the length of the encrypted message making it more difficult to be decrypted without knowing the decryption key However the public key length has no major affect on the private key length When the length of the message is changed then the length of the encrypted message will proportionally change hence larger chunks are selected to obtain larger encrypted message to increase the security of the data in use Journal of Applied Sciences 5 1: 60-63 2005 http://blogs.najah.edu/staff/allam-mousa/article/Evaluation-of-the-Sensitivity-of-Certain-JPEG-ParametersPublished ArticlesJordan Journal of Applied Science Natural Sciences 2005 Volume 7; Number 2 pages 68-78http://blogs.najah.edu/staff/allam-mousa/article/Data-encryption-performance-based-on-BlowfishPublished ArticlesSome of the important parameters of the blowfish encryption algorithm are being analyzed and examined to see how these parameters may affect the performance of the algorithm The performance indices here are the security and speed of the algorithm This study is applied to different types of data; text sound and image For each case the encryptiondecryption key length has been changed and its effect on the performance was noticed Moreover the file size is changed and its affect on the performance of the algorithm was noticed This has shown that changing the key length has no effect on the encryption or decryption time whereas changing the plaintext file size is directly reflected on the processing time The results obtained here have been converted into modules of equations of high orders thus the future performance of the algorithm may be predicted from these equations ELMAR 2005 47th International Symposium http://blogs.najah.edu/staff/allam-mousa/article/The-Role-of-Pitch-Filter-in-Pulse-by-Pulse-Reoptimization-of-the-LP-Synthesis-FilterPublished ArticlesTwo iterative analysis algorithms were developed for the reoptimization of the LP synthesis filter based on a pulse-by-pulse reoptimization manner In this study the use of the pitch filter in the analysis algorithms is introduced Similar to the no pitch case improvement in the gain is achieved On the other hand this gain has dropped compared to the no pitch case Moreover the number of pulses needed to reoptimize the LP filter found to be much less than that in the no pitch case An-Najah University Journal for Research - Natural Sciences A ISSN: 1727-2114 Volume 16 Issue 2 2002 Pages: 103-115http://blogs.najah.edu/staff/allam-mousa/article/Pulse-by-pulse-reoptimization-of-the-synthesis-filter-inpulse-based-codersPublished ArticlesTwo iterative algorithms for pulse-based linear predictive PB-LP analysis are developed At the kth step one of the algorithms assumes that the pulse locations of k pulses are known and calculates the LP coefficients jointly with k pulse amplitudes In contrast the other algorithm assumes that the previous k-1 pulse amplitudes are known and jointly estimates the LP filter coefficients and the kth pulse amplitude These algorithms are proposed for synthesis filter reoptimization in pulse-based LP coders and their effectiveness in multipulse coding is demonstrated through several simulations